On Fri, Jun 09, 2017 at 02:59:20PM +0200, Neil Armstrong wrote:

On 05/30/2017 04:23 PM, Russell King wrote:

...

Add CEC notifier support to the HDMI bridge driver, so that the CEC part of the IP can receive its physical address.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 4e1f54a675d8..966422576c44 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -36,7 +36,10 @@ #include "dw-hdmi.h" #include "dw-hdmi-audio.h"

+#include <media/cec-notifier.h>

#define DDC_SEGMENT_ADDR 0x30

#define HDMI_EDID_LEN 512

enum hdmi_datamap { @@ -173,6 +176,8 @@ struct dw_hdmi {

unsigned int reg_shift; struct regmap *regm;

• struct cec_notifier *cec_notifier;

};

#define HDMI_IH_PHY_STAT0_RX_SENSE \ @@ -1870,6 +1875,7 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector) hdmi->sink_is_hdmi = drm_detect_hdmi_monitor(edid); hdmi->sink_has_audio = drm_detect_monitor_audio(edid); drm_mode_connector_update_edid_property(connector, edid);

• cec_notifier_set_phys_addr_from_edid(hdmi->cec_notifier, edid);
  

  ret = drm_add_edid_modes(connector, edid); /* Store the ELD */ drm_edid_to_eld(connector, edid);

@@ -2108,11 +2114,16 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) * ask the source to re-read the EDID. */ if (intr_stat &

•    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD))
  

•    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD)) {
  

  __dw_hdmi_setup_rx_sense(hdmi, phy_stat & HDMI_PHY_HPD, phy_stat & HDMI_PHY_RX_SENSE);

• if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0)
  

• 	cec_notifier_set_phys_addr(hdmi->cec_notifier,
  

• 				   CEC_PHYS_ADDR_INVALID);
  

• }

• if (intr_stat & HDMI_IH_PHY_STAT0_HPD) { dev_dbg(hdmi->dev, "EVENT=%s\n", phy_int_pol & HDMI_PHY_HPD ? "plugin" : "plugout");

@@ -2365,6 +2376,12 @@ __dw_hdmi_probe(struct platform_device *pdev, if (ret) goto err_iahb;

• hdmi->cec_notifier = cec_notifier_get(dev);
• if (!hdmi->cec_notifier) {

• ret = -ENOMEM;
  

• goto err_iahb;
  

• }
• /*
  • To prevent overflows in HDMI_IH_FC_STAT2, set the clk regenerator
  • N and cts values before enabling phy

@@ -2437,6 +2454,9 @@ __dw_hdmi_probe(struct platform_device *pdev, hdmi->ddc = NULL; }

• if (hdmi->cec_notifier)

• cec_notifier_put(hdmi->cec_notifier);
  

• clk_disable_unprepare(hdmi->iahb_clk);

err_isfr: clk_disable_unprepare(hdmi->isfr_clk);

Hi Archit,

I think this one could go through drm-next since it's quite standalone and will reduce the DW-HDMI CEC patchset and dependencies.

Not a good idea. If you read all the comments, Hans is suggesting that CEC should be part of dw-hdmi itself, not stand-alone. That would mean this patch probably changes - basically, with CEC support built-in to dw-hdmi, we don't need the notifier stuff.

So, I'd suggest _not_ merging it at the moment, because the patch could well become obsolete.

Wait until the CEC changes that Hans has talked about have hit mainline and I've had a chance to rework this for those. We're waiting on Mauro for that at the moment.

(I do find it rather frustrating that CEC seems to evolve very rapidly, it makes it quite difficult to publish a patch set, and get it merged.)

On 06/09/2017 03:38 PM, Russell King - ARM Linux wrote:

On Fri, Jun 09, 2017 at 02:59:20PM +0200, Neil Armstrong wrote:

...

On 05/30/2017 04:23 PM, Russell King wrote:

...

Add CEC notifier support to the HDMI bridge driver, so that the CEC part of the IP can receive its physical address.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 4e1f54a675d8..966422576c44 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -36,7 +36,10 @@ #include "dw-hdmi.h" #include "dw-hdmi-audio.h"

+#include <media/cec-notifier.h>

#define DDC_SEGMENT_ADDR 0x30

#define HDMI_EDID_LEN 512

enum hdmi_datamap { @@ -173,6 +176,8 @@ struct dw_hdmi {

unsigned int reg_shift; struct regmap *regm;

• struct cec_notifier *cec_notifier;

};

#define HDMI_IH_PHY_STAT0_RX_SENSE \ @@ -1870,6 +1875,7 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector) hdmi->sink_is_hdmi = drm_detect_hdmi_monitor(edid); hdmi->sink_has_audio = drm_detect_monitor_audio(edid); drm_mode_connector_update_edid_property(connector, edid);

• cec_notifier_set_phys_addr_from_edid(hdmi->cec_notifier, edid);
  

  ret = drm_add_edid_modes(connector, edid); /* Store the ELD */ drm_edid_to_eld(connector, edid);

@@ -2108,11 +2114,16 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) * ask the source to re-read the EDID. */ if (intr_stat &

•    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD))
  

•    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD)) {
  

  __dw_hdmi_setup_rx_sense(hdmi, phy_stat & HDMI_PHY_HPD, phy_stat & HDMI_PHY_RX_SENSE);

• if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0)
  

• 	cec_notifier_set_phys_addr(hdmi->cec_notifier,
  

• 				   CEC_PHYS_ADDR_INVALID);
  

• }

• if (intr_stat & HDMI_IH_PHY_STAT0_HPD) { dev_dbg(hdmi->dev, "EVENT=%s\n", phy_int_pol & HDMI_PHY_HPD ? "plugin" : "plugout");

@@ -2365,6 +2376,12 @@ __dw_hdmi_probe(struct platform_device *pdev, if (ret) goto err_iahb;

• hdmi->cec_notifier = cec_notifier_get(dev);
• if (!hdmi->cec_notifier) {

• ret = -ENOMEM;
  

• goto err_iahb;
  

• }
• /*
  • To prevent overflows in HDMI_IH_FC_STAT2, set the clk regenerator
  • N and cts values before enabling phy

@@ -2437,6 +2454,9 @@ __dw_hdmi_probe(struct platform_device *pdev, hdmi->ddc = NULL; }

• if (hdmi->cec_notifier)

• cec_notifier_put(hdmi->cec_notifier);
  

• clk_disable_unprepare(hdmi->iahb_clk);

err_isfr: clk_disable_unprepare(hdmi->isfr_clk);

Hi Archit,

I think this one could go through drm-next since it's quite standalone and will reduce the DW-HDMI CEC patchset and dependencies.

Not a good idea. If you read all the comments, Hans is suggesting that CEC should be part of dw-hdmi itself, not stand-alone. That would mean this patch probably changes - basically, with CEC support built-in to dw-hdmi, we don't need the notifier stuff.

Hi Russell,

Yes, but on the Amlogic Meson plarform, the DW-HDMI CEC controller is not used, but a custom one, so this notifier is actually useful for this platform and maybe others.

So, I'd suggest _not_ merging it at the moment, because the patch could well become obsolete.

It won't since the Meson platform needs it...

Wait until the CEC changes that Hans has talked about have hit mainline and I've had a chance to rework this for those. We're waiting on Mauro for that at the moment.

(I do find it rather frustrating that CEC seems to evolve very rapidly, it makes it quite difficult to publish a patch set, and get it merged.)

Should we really wait until I push the Amlogic AO CEC driver ? Having a notifier in the DW-HDMI driver won't harm anybody since it *will be used*.

Neil

On 30/05/17 16:23, Russell King wrote:

The video setup path aways sets the clock disable register to a specific value, which has the effect of disabling the CEC engine. When we add the CEC driver, this becomes a problem.

Fix this by only setting/clearing the bits that the video path needs to.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

For what it is worth:

Acked-by: Hans Verkuil hans.verkuil@cisco.com

Regards,

Hans

---

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 966422576c44..58781d4c1034 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -166,6 +166,7 @@ struct dw_hdmi { bool bridge_is_on; /* indicates the bridge is on */ bool rxsense; /* rxsense state */ u8 phy_mask; /* desired phy int mask settings */

• u8 mc_clkdis; /* clock disable register */

  spinlock_t audio_lock; struct mutex audio_mutex;

@@ -1543,8 +1544,6 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi, /* HDMI Initialization Step B.4 */ static void dw_hdmi_enable_video_path(struct dw_hdmi *hdmi) {

• u8 clkdis;
• /* control period minimum duration */ hdmi_writeb(hdmi, 12, HDMI_FC_CTRLDUR); hdmi_writeb(hdmi, 32, HDMI_FC_EXCTRLDUR);

@@ -1556,17 +1555,21 @@ static void dw_hdmi_enable_video_path(struct dw_hdmi *hdmi) hdmi_writeb(hdmi, 0x21, HDMI_FC_CH2PREAM);

/* Enable pixel clock and tmds data path */

• clkdis = 0x7F;
• clkdis &= ~HDMI_MC_CLKDIS_PIXELCLK_DISABLE;
• hdmi_writeb(hdmi, clkdis, HDMI_MC_CLKDIS);

• hdmi->mc_clkdis |= HDMI_MC_CLKDIS_HDCPCLK_DISABLE |

• 	   HDMI_MC_CLKDIS_CSCCLK_DISABLE |
  

• 	   HDMI_MC_CLKDIS_AUDCLK_DISABLE |
  

• 	   HDMI_MC_CLKDIS_PREPCLK_DISABLE |
  

• 	   HDMI_MC_CLKDIS_TMDSCLK_DISABLE;
  

• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_PIXELCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);

• clkdis &= ~HDMI_MC_CLKDIS_TMDSCLK_DISABLE;
• hdmi_writeb(hdmi, clkdis, HDMI_MC_CLKDIS);

• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_TMDSCLK_DISABLE;

• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);

  /* Enable csc path */ if (is_color_space_conversion(hdmi)) {

• clkdis &= ~HDMI_MC_CLKDIS_CSCCLK_DISABLE;
  

• hdmi_writeb(hdmi, clkdis, HDMI_MC_CLKDIS);
  

• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_CSCCLK_DISABLE;
  

• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
  

  }

  /* Enable color space conversion if needed */

@@ -1580,7 +1583,8 @@ static void dw_hdmi_enable_video_path(struct dw_hdmi *hdmi)

static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi) {

• hdmi_modb(hdmi, 0, HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);

• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_AUDCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);

}

/* Workaround to clear the overflow condition */ @@ -2261,6 +2265,7 @@ __dw_hdmi_probe(struct platform_device *pdev, hdmi->disabled = true; hdmi->rxsense = true; hdmi->phy_mask = (u8)~(HDMI_PHY_HPD | HDMI_PHY_RX_SENSE);

• hdmi->mc_clkdis = 0x7f;

  mutex_init(&hdmi->mutex); mutex_init(&hdmi->audio_mutex);

Hi Russell,

On 30-05-2017 15:23, Russell King wrote:

Add a CEC driver for the dw-hdmi hardware.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/Kconfig | 8 + drivers/gpu/drm/bridge/synopsys/Makefile | 1 + drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 320 ++++++++++++++++++++++++++ drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h | 19 ++ drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++- 5 files changed, 387 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h

diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig index 40d2827a6d19..bd30a0a07272 100644 --- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO help Support the I2S Audio interface which is part of the Synopsys Designware HDMI block.

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
• select MEDIA_CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

Synopsis -> Synopsys

•  Designware HDMI block.
  

diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile index 17aa7a65b57e..6fe415903668 100644 --- a/drivers/gpu/drm/bridge/synopsys/Makefile +++ b/drivers/gpu/drm/bridge/synopsys/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o +obj-$(CONFIG_DRM_DW_HDMI_CEC) += dw-hdmi-cec.o diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c new file mode 100644 index 000000000000..761ef5ae687d --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c @@ -0,0 +1,320 @@ +/*

• • Designware HDMI CEC driver
• • Copyright (C) 2015-2017 Russell King.
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License version 2 as
• • published by the Free Software Foundation.
• */

+#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h>

+#include <drm/drm_edid.h>

+#include <media/cec.h> +#include <media/cec-notifier.h>

+#include "dw-hdmi-cec.h"

+enum {

• HDMI_IH_CEC_STAT0 = 0x0106,
• HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
• HDMI_CEC_CTRL = 0x7d00,
• CEC_CTRL_START = BIT(0),
• CEC_CTRL_NORMAL = 1 << 1,
• HDMI_CEC_STAT = 0x7d01,
• CEC_STAT_DONE = BIT(0),
• CEC_STAT_EOM = BIT(1),
• CEC_STAT_NACK = BIT(2),
• CEC_STAT_ARBLOST = BIT(3),
• CEC_STAT_ERROR_INIT = BIT(4),
• CEC_STAT_ERROR_FOLL = BIT(5),
• CEC_STAT_WAKEUP = BIT(6),

I rather like the format HDMI_{REGISTER_NAME}_{FIELD_NAME} so that it clearly identifies this is a internal driver register and not a CEC core register, but I guess its up to you :)

• HDMI_CEC_MASK = 0x7d02,
• HDMI_CEC_POLARITY = 0x7d03,
• HDMI_CEC_INT = 0x7d04,
• HDMI_CEC_ADDR_L = 0x7d05,
• HDMI_CEC_ADDR_H = 0x7d06,
• HDMI_CEC_TX_CNT = 0x7d07,
• HDMI_CEC_RX_CNT = 0x7d08,
• HDMI_CEC_TX_DATA0 = 0x7d10,
• HDMI_CEC_RX_DATA0 = 0x7d20,
• HDMI_CEC_LOCK = 0x7d30,
• HDMI_CEC_WKUPCTRL = 0x7d31,

+};

+struct dw_hdmi_cec {

• struct dw_hdmi *hdmi;
• const struct dw_hdmi_cec_ops *ops;
• u32 addresses;
• struct cec_adapter *adap;
• struct cec_msg rx_msg;
• unsigned int tx_status;
• bool tx_done;
• bool rx_done;
• struct cec_notifier *notify;
• int retries;
• int irq;

+};

+static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset) +{

• cec->ops->write(cec->hdmi, val, offset);

+}

+static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset) +{

• return cec->ops->read(cec->hdmi, offset);

+}

+static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr) +{

• struct dw_hdmi_cec *cec = adap->priv;

You can use "cec = cec_get_drvdata(adap)" here, as in the rest of the code.

• u32 addresses;
• if (logical_addr == CEC_LOG_ADDR_INVALID)

• addresses = cec->addresses = 0;
  

• else

• addresses = cec->addresses |= BIT(logical_addr) | BIT(15);
  

• dw_hdmi_write(cec, addresses & 255, HDMI_CEC_ADDR_L);
• dw_hdmi_write(cec, addresses >> 8, HDMI_CEC_ADDR_H);
• return 0;

+}

+static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,

• 		u32 signal_free_time, struct cec_msg *msg)
  

+{

• struct dw_hdmi_cec *cec = adap->priv;
• unsigned i;
• cec->retries = attempts;

I think you should check first if CEC engine is in normal operation mode, as a safety measure.

• for (i = 0; i < msg->len; i++)

• dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
  

• dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
• dw_hdmi_write(cec, CEC_CTRL_NORMAL | CEC_CTRL_START, HDMI_CEC_CTRL);
• return 0;

+}

+static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• unsigned stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
• irqreturn_t ret = IRQ_HANDLED;
• if (stat == 0)

• return IRQ_NONE;
  

• dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
• if (stat & CEC_STAT_ERROR_INIT) {

• if (cec->retries) {
  

• 	unsigned v = dw_hdmi_read(cec, HDMI_CEC_CTRL);
  

• 	dw_hdmi_write(cec, v | CEC_CTRL_START, HDMI_CEC_CTRL);
  

• 	cec->retries -= 1;
  

• } else {
  

• 	cec->tx_status = CEC_TX_STATUS_MAX_RETRIES;
  

• 	cec->tx_done = true;
  

• 	ret = IRQ_WAKE_THREAD;
  

• }
  

• } else if (stat & CEC_STAT_DONE) {

• cec->tx_status = CEC_TX_STATUS_OK;
  

• cec->tx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• } else if (stat & CEC_STAT_NACK) {

• cec->tx_status = CEC_TX_STATUS_NACK;
  

• cec->tx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• }
• if (stat & CEC_STAT_EOM) {

• unsigned len, i;
  

• len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);
  

• if (len > sizeof(cec->rx_msg.msg))
  

• 	len = sizeof(cec->rx_msg.msg);
  

• for (i = 0; i < len; i++)
  

• 	cec->rx_msg.msg[i] =
  

• 		dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
  

• cec->rx_msg.len = len;
  

• smp_wmb();
  

• cec->rx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• }
• return ret;

+}

+static irqreturn_t dw_hdmi_cec_thread(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• if (cec->tx_done) {

• cec->tx_done = false;
  

• cec_transmit_done(adap, cec->tx_status, 0, 0, 0, 0);
  

• }
• if (cec->rx_done) {

• cec->rx_done = false;
  

• smp_rmb();
  

• cec_received_msg(adap, &cec->rx_msg);
  

• }
• return IRQ_HANDLED;

+}

+static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable) +{

• struct dw_hdmi_cec *cec = adap->priv;
• if (!enable) {

• dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
  

• dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
  

• cec->ops->disable(cec->hdmi);
  

• } else {

• unsigned irqs;
  

• dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);
  

• dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
  

• dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
  

• cec->ops->enable(cec->hdmi);
  

• irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
  

•        CEC_STAT_DONE;
  

• dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);
  

• dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);
  

• dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);
  

• }
• return 0;

+}

+static const struct cec_adap_ops dw_hdmi_cec_ops = {

• .adap_enable = dw_hdmi_cec_enable,
• .adap_log_addr = dw_hdmi_cec_log_addr,
• .adap_transmit = dw_hdmi_cec_transmit,

+};

+static void dw_hdmi_cec_del(void *data) +{

• struct dw_hdmi_cec *cec = data;
• cec_delete_adapter(cec->adap);

+}

+static int dw_hdmi_cec_probe(struct platform_device *pdev) +{

• struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
• struct dw_hdmi_cec *cec;
• int ret;
• if (!data)

• return -ENXIO;
  

• /*

• * Our device is just a convenience - we want to link to the real
  

• * hardware device here, so that userspace can see the association
  

• * between the HDMI hardware and its associated CEC chardev.
  

• */
  

• cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
• if (!cec)

• return -ENOMEM;
  

• cec->irq = data->irq;
• cec->ops = data->ops;
• cec->hdmi = data->hdmi;
• platform_set_drvdata(pdev, cec);
• dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
• dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
• dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
• dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
• cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",

• 			 CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
  

• 			 CEC_CAP_RC, CEC_MAX_LOG_ADDRS);
  

• if (IS_ERR(cec->adap))

• return PTR_ERR(cec->adap);
  

• /* override the module pointer */
• cec->adap->owner = THIS_MODULE;
• ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
• if (ret) {

• cec_delete_adapter(cec->adap);
  

• return ret;
  

• }
• ret = devm_request_threaded_irq(&pdev->dev, cec->irq,

• 			dw_hdmi_cec_hardirq,
  

• 			dw_hdmi_cec_thread, IRQF_SHARED,
  

• 			"dw-hdmi-cec", cec->adap);
  

• if (ret < 0)

• return ret;
  

• cec->notify = cec_notifier_get(pdev->dev.parent);
• if (!cec->notify)

• return -ENOMEM;
  

• ret = cec_register_adapter(cec->adap, pdev->dev.parent);
• if (ret < 0) {

• cec_notifier_put(cec->notify);
  

• return ret;
  

• }
• /*

• * CEC documentation says we must not call cec_delete_adapter
  

• * after a successful call to cec_register_adapter().
  

• */
  

• devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
• cec_register_cec_notifier(cec->adap, cec->notify);
• return 0;

+}

+static int dw_hdmi_cec_remove(struct platform_device *pdev) +{

• struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
• cec_unregister_adapter(cec->adap);
• cec_notifier_put(cec->notify);
• return 0;

+}

+static struct platform_driver dw_hdmi_cec_driver = {

• .probe = dw_hdmi_cec_probe,
• .remove = dw_hdmi_cec_remove,
• .driver = {

• .name = "dw-hdmi-cec",
  

• },

+}; +module_platform_driver(dw_hdmi_cec_driver);

+MODULE_AUTHOR("Russell King rmk+kernel@armlinux.org.uk"); +MODULE_DESCRIPTION("Synopsis Designware HDMI CEC driver for i.MX");

Synopsis -> Synopsys

+MODULE_LICENSE("GPL"); +MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec"); diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h new file mode 100644 index 000000000000..cf4dc121a2c4 --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h @@ -0,0 +1,19 @@ +#ifndef DW_HDMI_CEC_H +#define DW_HDMI_CEC_H

+struct dw_hdmi;

+struct dw_hdmi_cec_ops {

• void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
• u8 (*read)(struct dw_hdmi *hdmi, int offset);
• void (*enable)(struct dw_hdmi *hdmi);
• void (*disable)(struct dw_hdmi *hdmi);

+};

+struct dw_hdmi_cec_data {

• struct dw_hdmi *hdmi;
• const struct dw_hdmi_cec_ops *ops;
• int irq;

+};

+#endif diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 58781d4c1034..5a389f1f58d9 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -35,6 +35,7 @@

#include "dw-hdmi.h" #include "dw-hdmi-audio.h" +#include "dw-hdmi-cec.h"

#include <media/cec-notifier.h>

@@ -133,6 +134,7 @@ struct dw_hdmi { unsigned int version;

struct platform_device *audio;

• struct platform_device *cec; struct device *dev; struct clk *isfr_clk; struct clk *iahb_clk;

@@ -1766,7 +1768,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi) hdmi_writeb(hdmi, 0xff, HDMI_AUD_HBR_MASK); hdmi_writeb(hdmi, 0xff, HDMI_GP_MASK); hdmi_writeb(hdmi, 0xff, HDMI_A_APIINTMSK);

• hdmi_writeb(hdmi, 0xff, HDMI_CEC_MASK); hdmi_writeb(hdmi, 0xff, HDMI_I2CM_INT); hdmi_writeb(hdmi, 0xff, HDMI_I2CM_CTLINT);

@@ -2223,6 +2224,29 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi) return -ENODEV; }

+static void dw_hdmi_cec_enable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static void dw_hdmi_cec_disable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis |= HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static const struct dw_hdmi_cec_ops dw_hdmi_cec_ops = {

• .write = hdmi_writeb,
• .read = hdmi_readb,
• .enable = dw_hdmi_cec_enable,
• .disable = dw_hdmi_cec_disable,

+};

static const struct regmap_config hdmi_regmap_8bit_config = { .reg_bits = 32, .val_bits = 8, @@ -2245,6 +2269,7 @@ __dw_hdmi_probe(struct platform_device *pdev, struct device_node *np = dev->of_node; struct platform_device_info pdevinfo; struct device_node *ddc_node;

• struct dw_hdmi_cec_data cec; struct dw_hdmi *hdmi; struct resource *iores = NULL; int irq;

@@ -2445,6 +2470,17 @@ __dw_hdmi_probe(struct platform_device *pdev, hdmi->audio = platform_device_register_full(&pdevinfo); }

• cec.hdmi = hdmi;
• cec.ops = &dw_hdmi_cec_ops;
• cec.irq = irq;
• pdevinfo.name = "dw-hdmi-cec";
• pdevinfo.data = &cec;
• pdevinfo.size_data = sizeof(cec);
• pdevinfo.dma_mask = 0;
• hdmi->cec = platform_device_register_full(&pdevinfo);
• /* Reset HDMI DDC I2C master controller and mute I2CM interrupts */ if (hdmi->i2c) dw_hdmi_i2c_init(hdmi);

@@ -2475,6 +2511,8 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi) { if (hdmi->audio && !IS_ERR(hdmi->audio)) platform_device_unregister(hdmi->audio);

• if (!IS_ERR(hdmi->cec))

• platform_device_unregister(hdmi->cec);
  
  

  /* Disable all interrupts */ hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);

Best regards, Jose Miguel Abreu

Hi Russell,

First a few top-level questions:

1) What was the reason for using the cec-notifier here? Isn't this tightly integrated into the main dw-hdmi block? For the tda driver it is clearly required, but for tightly coupled HDMI & CEC HW I just create the adapter from the HDMI driver. As a small bonus it avoids adding the cec-notifier code and the control flow is a bit easier to trace.

2) I may have asked this before, apologies if I repeat myself: does this CEC implementation support CEC monitoring (aka snooping)? If it does, then I recommend that it is implemented since it is very useful.

3) Is the CEC still active if there is no hotplug signal? Or is it powered off in that case? Ideally it should still be possible to send CEC messages even if there is no hotplug. This is explicitly allowed by the CEC 2.0 spec to wake up displays that turn off the HPD, but that still have a working CEC controller.

If this is not possible, then you need to use the CEC_CAP_NEEDS_HPD capability. See: https://patchwork.linuxtv.org/patch/41478/

This will almost certainly be merged for 4.13 since other CEC drivers need this as well.

On 05/30/17 16:23, Russell King wrote:

Add a CEC driver for the dw-hdmi hardware.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/Kconfig | 8 + drivers/gpu/drm/bridge/synopsys/Makefile | 1 + drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 320 ++++++++++++++++++++++++++ drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h | 19 ++ drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++- 5 files changed, 387 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h

diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig index 40d2827a6d19..bd30a0a07272 100644 --- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO help Support the I2S Audio interface which is part of the Synopsys Designware HDMI block.

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
• select MEDIA_CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

•  Designware HDMI block.
  

This will change. Patches to fix the config handling are pending for 4.12.

Here you can see the pending patches: https://git.linuxtv.org/hverkuil/media_tree.git/log/?h=drm-cec

The patches from 'cec-notifier.h: handle unreachable CONFIG_CEC_CORE' to 'cec: drop MEDIA_CEC_DEBUG' should all be merged in 4.12.

That means that this config becomes:

+ +config DRM_DW_HDMI_CEC + tristate "Synopsis Designware CEC interface" + depends on DRM_DW_HDMI + select CEC_CORE + select CEC_NOTIFIER + help + Support the CE interface which is part of the Synopsis + Designware HDMI block.

diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile index 17aa7a65b57e..6fe415903668 100644 --- a/drivers/gpu/drm/bridge/synopsys/Makefile +++ b/drivers/gpu/drm/bridge/synopsys/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o +obj-$(CONFIG_DRM_DW_HDMI_CEC) += dw-hdmi-cec.o diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c new file mode 100644 index 000000000000..761ef5ae687d --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c @@ -0,0 +1,320 @@ +/*

• • Designware HDMI CEC driver
• • Copyright (C) 2015-2017 Russell King.
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License version 2 as
• • published by the Free Software Foundation.
• */

+#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h>

+#include <drm/drm_edid.h>

+#include <media/cec.h> +#include <media/cec-notifier.h>

+#include "dw-hdmi-cec.h"

+enum {

• HDMI_IH_CEC_STAT0 = 0x0106,
• HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
• HDMI_CEC_CTRL = 0x7d00,
• CEC_CTRL_START = BIT(0),
• CEC_CTRL_NORMAL = 1 << 1,
• HDMI_CEC_STAT = 0x7d01,
• CEC_STAT_DONE = BIT(0),
• CEC_STAT_EOM = BIT(1),
• CEC_STAT_NACK = BIT(2),
• CEC_STAT_ARBLOST = BIT(3),
• CEC_STAT_ERROR_INIT = BIT(4),
• CEC_STAT_ERROR_FOLL = BIT(5),
• CEC_STAT_WAKEUP = BIT(6),
• HDMI_CEC_MASK = 0x7d02,
• HDMI_CEC_POLARITY = 0x7d03,
• HDMI_CEC_INT = 0x7d04,
• HDMI_CEC_ADDR_L = 0x7d05,
• HDMI_CEC_ADDR_H = 0x7d06,
• HDMI_CEC_TX_CNT = 0x7d07,
• HDMI_CEC_RX_CNT = 0x7d08,
• HDMI_CEC_TX_DATA0 = 0x7d10,
• HDMI_CEC_RX_DATA0 = 0x7d20,
• HDMI_CEC_LOCK = 0x7d30,
• HDMI_CEC_WKUPCTRL = 0x7d31,

+};

+struct dw_hdmi_cec {

• struct dw_hdmi *hdmi;
• const struct dw_hdmi_cec_ops *ops;
• u32 addresses;
• struct cec_adapter *adap;
• struct cec_msg rx_msg;
• unsigned int tx_status;
• bool tx_done;
• bool rx_done;
• struct cec_notifier *notify;
• int retries;
• int irq;

+};

+static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset) +{

• cec->ops->write(cec->hdmi, val, offset);

+}

+static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset) +{

• return cec->ops->read(cec->hdmi, offset);

+}

+static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr) +{

• struct dw_hdmi_cec *cec = adap->priv;
• u32 addresses;
• if (logical_addr == CEC_LOG_ADDR_INVALID)

• addresses = cec->addresses = 0;
  

• else

• addresses = cec->addresses |= BIT(logical_addr) | BIT(15);
  

• dw_hdmi_write(cec, addresses & 255, HDMI_CEC_ADDR_L);
• dw_hdmi_write(cec, addresses >> 8, HDMI_CEC_ADDR_H);

The addresses local variable doesn't really seem needed.

• return 0;

+}

+static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,

• 		u32 signal_free_time, struct cec_msg *msg)
  

+{

• struct dw_hdmi_cec *cec = adap->priv;
• unsigned i;
• cec->retries = attempts;

Should probably be 'cec->retries = attempts - 1;' Since 2 attempts == 1 retry.

• for (i = 0; i < msg->len; i++)

• dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
  

• dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
• dw_hdmi_write(cec, CEC_CTRL_NORMAL | CEC_CTRL_START, HDMI_CEC_CTRL);
• return 0;

+}

+static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• unsigned stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
• irqreturn_t ret = IRQ_HANDLED;
• if (stat == 0)

• return IRQ_NONE;
  

• dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
• if (stat & CEC_STAT_ERROR_INIT) {

• if (cec->retries) {
  

• 	unsigned v = dw_hdmi_read(cec, HDMI_CEC_CTRL);
  

• 	dw_hdmi_write(cec, v | CEC_CTRL_START, HDMI_CEC_CTRL);
  

• 	cec->retries -= 1;
  

Why handle retries here at all? Just mark this as CEC_TX_STATUS_ERROR and set tx_done to true. The CEC core will just call dw_hdmi_cec_transmit again if it needs to make another attempt. I suggest that the whole retry code is dropped.

• } else {
  

• 	cec->tx_status = CEC_TX_STATUS_MAX_RETRIES;
  

• 	cec->tx_done = true;
  

• 	ret = IRQ_WAKE_THREAD;
  

• }
  

• } else if (stat & CEC_STAT_DONE) {

• cec->tx_status = CEC_TX_STATUS_OK;
  

• cec->tx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• } else if (stat & CEC_STAT_NACK) {

• cec->tx_status = CEC_TX_STATUS_NACK;
  

• cec->tx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• }
• if (stat & CEC_STAT_EOM) {

• unsigned len, i;
  

• len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);
  

• if (len > sizeof(cec->rx_msg.msg))
  

• 	len = sizeof(cec->rx_msg.msg);
  

• for (i = 0; i < len; i++)
  

• 	cec->rx_msg.msg[i] =
  

• 		dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
  

• cec->rx_msg.len = len;
  

• smp_wmb();
  

• cec->rx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• }
• return ret;

+}

+static irqreturn_t dw_hdmi_cec_thread(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• if (cec->tx_done) {

• cec->tx_done = false;
  

• cec_transmit_done(adap, cec->tx_status, 0, 0, 0, 0);
  

I think I will make a patch for a new helper function where you can just call:

cec_transmit_attempt_done(adap, cec->tx_status);

and that will call cec_transmit_done filling in the other arguments based on the status.

Most CEC HW doesn't do retries so only make one attempt. In that case only one of the remaining count arguments is 1 and that's based on the status.

Having correct error counts is useful for debugging problems.

• }
• if (cec->rx_done) {

• cec->rx_done = false;
  

• smp_rmb();
  

• cec_received_msg(adap, &cec->rx_msg);
  

• }
• return IRQ_HANDLED;

+}

+static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable) +{

• struct dw_hdmi_cec *cec = adap->priv;
• if (!enable) {

• dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
  

• dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
  

• cec->ops->disable(cec->hdmi);
  

• } else {

• unsigned irqs;
  

• dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);
  

• dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
  

• dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
  

• cec->ops->enable(cec->hdmi);
  

• irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
  

•        CEC_STAT_DONE;
  

• dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);
  

• dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);
  

• dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);
  

• }
• return 0;

+}

+static const struct cec_adap_ops dw_hdmi_cec_ops = {

• .adap_enable = dw_hdmi_cec_enable,
• .adap_log_addr = dw_hdmi_cec_log_addr,
• .adap_transmit = dw_hdmi_cec_transmit,

+};

+static void dw_hdmi_cec_del(void *data) +{

• struct dw_hdmi_cec *cec = data;
• cec_delete_adapter(cec->adap);

+}

+static int dw_hdmi_cec_probe(struct platform_device *pdev) +{

• struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
• struct dw_hdmi_cec *cec;
• int ret;
• if (!data)

• return -ENXIO;
  

• /*

• * Our device is just a convenience - we want to link to the real
  

• * hardware device here, so that userspace can see the association
  

• * between the HDMI hardware and its associated CEC chardev.
  

• */
  

• cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
• if (!cec)

• return -ENOMEM;
  

• cec->irq = data->irq;
• cec->ops = data->ops;
• cec->hdmi = data->hdmi;
• platform_set_drvdata(pdev, cec);
• dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
• dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
• dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
• dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
• cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",

• 			 CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
  

• 			 CEC_CAP_RC, CEC_MAX_LOG_ADDRS);
  

• if (IS_ERR(cec->adap))

• return PTR_ERR(cec->adap);
  

• /* override the module pointer */
• cec->adap->owner = THIS_MODULE;
• ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
• if (ret) {

• cec_delete_adapter(cec->adap);
  

• return ret;
  

• }
• ret = devm_request_threaded_irq(&pdev->dev, cec->irq,

• 			dw_hdmi_cec_hardirq,
  

• 			dw_hdmi_cec_thread, IRQF_SHARED,
  

• 			"dw-hdmi-cec", cec->adap);
  

• if (ret < 0)

• return ret;
  

• cec->notify = cec_notifier_get(pdev->dev.parent);
• if (!cec->notify)

• return -ENOMEM;
  

• ret = cec_register_adapter(cec->adap, pdev->dev.parent);
• if (ret < 0) {

• cec_notifier_put(cec->notify);
  

• return ret;
  

• }
• /*

• * CEC documentation says we must not call cec_delete_adapter
  

• * after a successful call to cec_register_adapter().
  

• */
  

• devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
• cec_register_cec_notifier(cec->adap, cec->notify);
• return 0;

+}

+static int dw_hdmi_cec_remove(struct platform_device *pdev) +{

• struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
• cec_unregister_adapter(cec->adap);
• cec_notifier_put(cec->notify);
• return 0;

+}

+static struct platform_driver dw_hdmi_cec_driver = {

• .probe = dw_hdmi_cec_probe,
• .remove = dw_hdmi_cec_remove,
• .driver = {

• .name = "dw-hdmi-cec",
  

• },

+}; +module_platform_driver(dw_hdmi_cec_driver);

+MODULE_AUTHOR("Russell King rmk+kernel@armlinux.org.uk"); +MODULE_DESCRIPTION("Synopsis Designware HDMI CEC driver for i.MX"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec"); diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h new file mode 100644 index 000000000000..cf4dc121a2c4 --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h @@ -0,0 +1,19 @@ +#ifndef DW_HDMI_CEC_H +#define DW_HDMI_CEC_H

+struct dw_hdmi;

+struct dw_hdmi_cec_ops {

• void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
• u8 (*read)(struct dw_hdmi *hdmi, int offset);
• void (*enable)(struct dw_hdmi *hdmi);
• void (*disable)(struct dw_hdmi *hdmi);

+};

+struct dw_hdmi_cec_data {

• struct dw_hdmi *hdmi;
• const struct dw_hdmi_cec_ops *ops;
• int irq;

+};

+#endif diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 58781d4c1034..5a389f1f58d9 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -35,6 +35,7 @@

#include "dw-hdmi.h" #include "dw-hdmi-audio.h" +#include "dw-hdmi-cec.h"

#include <media/cec-notifier.h>

@@ -133,6 +134,7 @@ struct dw_hdmi { unsigned int version;

struct platform_device *audio;

• struct platform_device *cec; struct device *dev; struct clk *isfr_clk; struct clk *iahb_clk;

@@ -1766,7 +1768,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi) hdmi_writeb(hdmi, 0xff, HDMI_AUD_HBR_MASK); hdmi_writeb(hdmi, 0xff, HDMI_GP_MASK); hdmi_writeb(hdmi, 0xff, HDMI_A_APIINTMSK);

• hdmi_writeb(hdmi, 0xff, HDMI_CEC_MASK); hdmi_writeb(hdmi, 0xff, HDMI_I2CM_INT); hdmi_writeb(hdmi, 0xff, HDMI_I2CM_CTLINT);

@@ -2223,6 +2224,29 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi) return -ENODEV; }

+static void dw_hdmi_cec_enable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static void dw_hdmi_cec_disable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis |= HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static const struct dw_hdmi_cec_ops dw_hdmi_cec_ops = {

• .write = hdmi_writeb,
• .read = hdmi_readb,
• .enable = dw_hdmi_cec_enable,
• .disable = dw_hdmi_cec_disable,

+};

This feels over-engineered and I suspect it is simplified if you just add a cec_adapter pointer to struct dw_hdmi and link dw-hdmi-cec.c together with dw-hdmi.c.

In other implementations I have done (see e.g. the recent drm displayport CEC patch series) this works quite well.

static const struct regmap_config hdmi_regmap_8bit_config = { .reg_bits = 32, .val_bits = 8, @@ -2245,6 +2269,7 @@ __dw_hdmi_probe(struct platform_device *pdev, struct device_node *np = dev->of_node; struct platform_device_info pdevinfo; struct device_node *ddc_node;

• struct dw_hdmi_cec_data cec; struct dw_hdmi *hdmi; struct resource *iores = NULL; int irq;

@@ -2445,6 +2470,17 @@ __dw_hdmi_probe(struct platform_device *pdev, hdmi->audio = platform_device_register_full(&pdevinfo); }

• cec.hdmi = hdmi;
• cec.ops = &dw_hdmi_cec_ops;
• cec.irq = irq;
• pdevinfo.name = "dw-hdmi-cec";
• pdevinfo.data = &cec;
• pdevinfo.size_data = sizeof(cec);
• pdevinfo.dma_mask = 0;
• hdmi->cec = platform_device_register_full(&pdevinfo);
• /* Reset HDMI DDC I2C master controller and mute I2CM interrupts */ if (hdmi->i2c) dw_hdmi_i2c_init(hdmi);

@@ -2475,6 +2511,8 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi) { if (hdmi->audio && !IS_ERR(hdmi->audio)) platform_device_unregister(hdmi->audio);

• if (!IS_ERR(hdmi->cec))

• platform_device_unregister(hdmi->cec);
  
  

  /* Disable all interrupts */ hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);

Regards,

Hans

On 06/01/17 11:46, Russell King - ARM Linux wrote:

On Thu, Jun 01, 2017 at 10:31:10AM +0200, Hans Verkuil wrote:

...

Hi Russell,

First a few top-level questions:

Hi Hans,

...

1. What was the reason for using the cec-notifier here? Isn't this tightly integrated into the main dw-hdmi block? For the tda driver it is clearly required, but for tightly coupled HDMI & CEC HW I just create the adapter from the HDMI driver. As a small bonus it avoids adding the cec-notifier code and the control flow is a bit easier to trace.

It's to avoid complex dependencies. If it's all built in to the HDMI driver, then the HDMI driver needs to depend on all the media stuff being non-modular. For a video output device, this is sub-optimal, because you want the video output device to work during boot.

This is no longer true after my rework of the CEC kernel config.

After doing a 'select CEC_CORE' the cec framework will be compiled correctly.

It no longer depends on the media subsystem (except if you want to use the remote control passthrough since the RC framework is part of media).

Selecting CEC_CORE will only select the cec core code.

I feel strongly about this point, especially as we have had many years of users being able to use dw-hdmi without needing CEC enabled.

...

2. I may have asked this before, apologies if I repeat myself: does this CEC implementation support CEC monitoring (aka snooping)? If it does, then I recommend that it is implemented since it is very useful.

It does not.

...

3. Is the CEC still active if there is no hotplug signal? Or is it powered off in that case? Ideally it should still be possible to send CEC messages even if there is no hotplug. This is explicitly allowed by the CEC 2.0 spec to wake up displays that turn off the HPD, but that still have a working CEC controller.

This is not specified in the documentation, so I don't think we know without experimentation. This would be a future enhancement to the patch set.

...

...

diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig index 40d2827a6d19..bd30a0a07272 100644 --- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO help Support the I2S Audio interface which is part of the Synopsys Designware HDMI block.

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
• select MEDIA_CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

•  Designware HDMI block.
  

This will change. Patches to fix the config handling are pending for 4.12.

Here you can see the pending patches: https://git.linuxtv.org/hverkuil/media_tree.git/log/?h=drm-cec

The patches from 'cec-notifier.h: handle unreachable CONFIG_CEC_CORE' to 'cec: drop MEDIA_CEC_DEBUG' should all be merged in 4.12.

That means that this config becomes:

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI
• select CEC_CORE
• select CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

•  Designware HDMI block.
  

You will also need to select MEDIA_SUPPORT to avoid dependency issues. CEC_CORE and CEC_NOTIFIER are both lumped under an "if MEDIA_SUPPORT" block in drivers/media/Kconfig, so they depend on this symbol.

No, they've been moved up. They no longer depend on the MEDIA_SUPPORT. So that's been fixed.

Asking Kconfig to select these two symbols without MEDIA_SUPPORT creates an invalid configuration - unless CEC has been moved out from being under MEDIA_SUPPORT. (I haven't looked at your tree yet.)

...

...

+static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr) +{

• struct dw_hdmi_cec *cec = adap->priv;
• u32 addresses;
• if (logical_addr == CEC_LOG_ADDR_INVALID)

• addresses = cec->addresses = 0;
  

• else

• addresses = cec->addresses |= BIT(logical_addr) | BIT(15);
  

• dw_hdmi_write(cec, addresses & 255, HDMI_CEC_ADDR_L);
• dw_hdmi_write(cec, addresses >> 8, HDMI_CEC_ADDR_H);

The addresses local variable doesn't really seem needed.

Ok.

...

...

+static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,

• 		u32 signal_free_time, struct cec_msg *msg)
  

+{

• struct dw_hdmi_cec *cec = adap->priv;
• unsigned i;
• cec->retries = attempts;

Should probably be 'cec->retries = attempts - 1;' Since 2 attempts == 1 retry.

Probably correct, but rather moot given your comment below.

...

...

+static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• unsigned stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
• irqreturn_t ret = IRQ_HANDLED;
• if (stat == 0)

• return IRQ_NONE;
  

• dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
• if (stat & CEC_STAT_ERROR_INIT) {

• if (cec->retries) {
  

• 	unsigned v = dw_hdmi_read(cec, HDMI_CEC_CTRL);
  

• 	dw_hdmi_write(cec, v | CEC_CTRL_START, HDMI_CEC_CTRL);
  

• 	cec->retries -= 1;
  

Why handle retries here at all? Just mark this as CEC_TX_STATUS_ERROR and set tx_done to true. The CEC core will just call dw_hdmi_cec_transmit again if it needs to make another attempt. I suggest that the whole retry code is dropped.

Probably comes from a previous iteration of your CEC core which required the driver to do retries, so it can probably be fixed up in the way you describe.

However, presumably this needs a different status other than "CEC_TX_STATUS_MAX_RETRIES"? I don't see a way to report this error to the CEC core in a way that it will retry.

If the framework does the retries, then the cec driver will never return the MAX_RETRIES status. Just whether the transmit was OK/NACKed/LOW_DRIVE/ERROR.

...

...

+static irqreturn_t dw_hdmi_cec_thread(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• if (cec->tx_done) {

• cec->tx_done = false;
  

• cec_transmit_done(adap, cec->tx_status, 0, 0, 0, 0);
  

I think I will make a patch for a new helper function where you can just call:

cec_transmit_attempt_done(adap, cec->tx_status);

and that will call cec_transmit_done filling in the other arguments based on the status.

Most CEC HW doesn't do retries so only make one attempt. In that case only one of the remaining count arguments is 1 and that's based on the status.

Having correct error counts is useful for debugging problems.

It hasn't been clear to me which counts should be non-zero, and it seems like entirely redundant information given that the status argument indicates what happened to the message.

True for HW that doesn't retry. Expect a patch today/tomorrow.

...

...

+static void dw_hdmi_cec_disable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis |= HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static const struct dw_hdmi_cec_ops dw_hdmi_cec_ops = {

• .write = hdmi_writeb,
• .read = hdmi_readb,
• .enable = dw_hdmi_cec_enable,
• .disable = dw_hdmi_cec_disable,

+};

This feels over-engineered and I suspect it is simplified if you just add a cec_adapter pointer to struct dw_hdmi and link dw-hdmi-cec.c together with dw-hdmi.c.

As I mention above, to do so would mean that dw-hdmi has to be modular if you want CEC to be modular, and I don't think that is reasonable for a video output device, which may be the source of kernel boot messages.

Indeed, but this dependency mess has been fixed, so this is no longer an issue.

Regards,

Hans

On 05/30/2017 04:23 PM, Russell King wrote:

Add a CEC driver for the dw-hdmi hardware.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/Kconfig | 8 + drivers/gpu/drm/bridge/synopsys/Makefile | 1 + drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 320 ++++++++++++++++++++++++++ drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h | 19 ++ drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++- 5 files changed, 387 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h

diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig index 40d2827a6d19..bd30a0a07272 100644 --- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO help Support the I2S Audio interface which is part of the Synopsys Designware HDMI block.

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
• select MEDIA_CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

•  Designware HDMI block.
  

diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile index 17aa7a65b57e..6fe415903668 100644 --- a/drivers/gpu/drm/bridge/synopsys/Makefile +++ b/drivers/gpu/drm/bridge/synopsys/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o +obj-$(CONFIG_DRM_DW_HDMI_CEC) += dw-hdmi-cec.o diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c new file mode 100644 index 000000000000..761ef5ae687d --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c @@ -0,0 +1,320 @@ +/*

• • Designware HDMI CEC driver
• • Copyright (C) 2015-2017 Russell King.
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License version 2 as
• • published by the Free Software Foundation.
• */

+#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h>

+#include <drm/drm_edid.h>

+#include <media/cec.h> +#include <media/cec-notifier.h>

+#include "dw-hdmi-cec.h"

+enum {

• HDMI_IH_CEC_STAT0 = 0x0106,
• HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
• HDMI_CEC_CTRL = 0x7d00,
• CEC_CTRL_START = BIT(0),
• CEC_CTRL_NORMAL = 1 << 1,
• HDMI_CEC_STAT = 0x7d01,
• CEC_STAT_DONE = BIT(0),
• CEC_STAT_EOM = BIT(1),
• CEC_STAT_NACK = BIT(2),
• CEC_STAT_ARBLOST = BIT(3),
• CEC_STAT_ERROR_INIT = BIT(4),
• CEC_STAT_ERROR_FOLL = BIT(5),
• CEC_STAT_WAKEUP = BIT(6),
• HDMI_CEC_MASK = 0x7d02,
• HDMI_CEC_POLARITY = 0x7d03,
• HDMI_CEC_INT = 0x7d04,
• HDMI_CEC_ADDR_L = 0x7d05,
• HDMI_CEC_ADDR_H = 0x7d06,
• HDMI_CEC_TX_CNT = 0x7d07,
• HDMI_CEC_RX_CNT = 0x7d08,
• HDMI_CEC_TX_DATA0 = 0x7d10,
• HDMI_CEC_RX_DATA0 = 0x7d20,
• HDMI_CEC_LOCK = 0x7d30,
• HDMI_CEC_WKUPCTRL = 0x7d31,

+};

+struct dw_hdmi_cec {

• struct dw_hdmi *hdmi;
• const struct dw_hdmi_cec_ops *ops;
• u32 addresses;
• struct cec_adapter *adap;
• struct cec_msg rx_msg;
• unsigned int tx_status;
• bool tx_done;
• bool rx_done;
• struct cec_notifier *notify;
• int retries;
• int irq;

+};

+static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset) +{

• cec->ops->write(cec->hdmi, val, offset);

+}

+static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset) +{

• return cec->ops->read(cec->hdmi, offset);

+}

+static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr) +{

• struct dw_hdmi_cec *cec = adap->priv;
• u32 addresses;
• if (logical_addr == CEC_LOG_ADDR_INVALID)

• addresses = cec->addresses = 0;
  

• else

• addresses = cec->addresses |= BIT(logical_addr) | BIT(15);
  

• dw_hdmi_write(cec, addresses & 255, HDMI_CEC_ADDR_L);
• dw_hdmi_write(cec, addresses >> 8, HDMI_CEC_ADDR_H);
• return 0;

+}

+static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,

• 		u32 signal_free_time, struct cec_msg *msg)
  

+{

• struct dw_hdmi_cec *cec = adap->priv;
• unsigned i;
• cec->retries = attempts;
• for (i = 0; i < msg->len; i++)

• dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
  

• dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
• dw_hdmi_write(cec, CEC_CTRL_NORMAL | CEC_CTRL_START, HDMI_CEC_CTRL);
• return 0;

+}

+static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• unsigned stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
• irqreturn_t ret = IRQ_HANDLED;
• if (stat == 0)

• return IRQ_NONE;
  

• dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
• if (stat & CEC_STAT_ERROR_INIT) {

• if (cec->retries) {
  

• 	unsigned v = dw_hdmi_read(cec, HDMI_CEC_CTRL);
  

• 	dw_hdmi_write(cec, v | CEC_CTRL_START, HDMI_CEC_CTRL);
  

• 	cec->retries -= 1;
  

• } else {
  

• 	cec->tx_status = CEC_TX_STATUS_MAX_RETRIES;
  

• 	cec->tx_done = true;
  

• 	ret = IRQ_WAKE_THREAD;
  

• }
  

• } else if (stat & CEC_STAT_DONE) {

• cec->tx_status = CEC_TX_STATUS_OK;
  

• cec->tx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• } else if (stat & CEC_STAT_NACK) {

• cec->tx_status = CEC_TX_STATUS_NACK;
  

• cec->tx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• }
• if (stat & CEC_STAT_EOM) {

• unsigned len, i;
  

• len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);
  

• if (len > sizeof(cec->rx_msg.msg))
  

• 	len = sizeof(cec->rx_msg.msg);
  

• for (i = 0; i < len; i++)
  

• 	cec->rx_msg.msg[i] =
  

• 		dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
  

• cec->rx_msg.len = len;
  

• smp_wmb();
  

• cec->rx_done = true;
  

• ret = IRQ_WAKE_THREAD;
  

• }
• return ret;

+}

+static irqreturn_t dw_hdmi_cec_thread(int irq, void *data) +{

• struct cec_adapter *adap = data;
• struct dw_hdmi_cec *cec = adap->priv;
• if (cec->tx_done) {

• cec->tx_done = false;
  

• cec_transmit_done(adap, cec->tx_status, 0, 0, 0, 0);
  

• }
• if (cec->rx_done) {

• cec->rx_done = false;
  

• smp_rmb();
  

• cec_received_msg(adap, &cec->rx_msg);
  

• }
• return IRQ_HANDLED;

+}

+static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable) +{

• struct dw_hdmi_cec *cec = adap->priv;
• if (!enable) {

• dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
  

• dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
  

• cec->ops->disable(cec->hdmi);
  

• } else {

• unsigned irqs;
  

• dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);
  

• dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);
  

• dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
  

• dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
  

• cec->ops->enable(cec->hdmi);
  

• irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
  

•        CEC_STAT_DONE;
  

• dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);
  

• dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);
  

• dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);
  

• }
• return 0;

+}

+static const struct cec_adap_ops dw_hdmi_cec_ops = {

• .adap_enable = dw_hdmi_cec_enable,
• .adap_log_addr = dw_hdmi_cec_log_addr,
• .adap_transmit = dw_hdmi_cec_transmit,

+};

+static void dw_hdmi_cec_del(void *data) +{

• struct dw_hdmi_cec *cec = data;
• cec_delete_adapter(cec->adap);

+}

+static int dw_hdmi_cec_probe(struct platform_device *pdev) +{

• struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
• struct dw_hdmi_cec *cec;
• int ret;
• if (!data)

• return -ENXIO;
  

• /*

• * Our device is just a convenience - we want to link to the real
  

• * hardware device here, so that userspace can see the association
  

• * between the HDMI hardware and its associated CEC chardev.
  

• */
  

• cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
• if (!cec)

• return -ENOMEM;
  

• cec->irq = data->irq;
• cec->ops = data->ops;
• cec->hdmi = data->hdmi;
• platform_set_drvdata(pdev, cec);
• dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
• dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
• dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
• dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
• cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",

• 			 CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
  

• 			 CEC_CAP_RC, CEC_MAX_LOG_ADDRS);
  

• if (IS_ERR(cec->adap))

• return PTR_ERR(cec->adap);
  

• /* override the module pointer */
• cec->adap->owner = THIS_MODULE;
• ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
• if (ret) {

• cec_delete_adapter(cec->adap);
  

• return ret;
  

• }
• ret = devm_request_threaded_irq(&pdev->dev, cec->irq,

• 			dw_hdmi_cec_hardirq,
  

• 			dw_hdmi_cec_thread, IRQF_SHARED,
  

• 			"dw-hdmi-cec", cec->adap);
  

• if (ret < 0)

• return ret;
  

• cec->notify = cec_notifier_get(pdev->dev.parent);
• if (!cec->notify)

• return -ENOMEM;
  

• ret = cec_register_adapter(cec->adap, pdev->dev.parent);
• if (ret < 0) {

• cec_notifier_put(cec->notify);
  

• return ret;
  

• }
• /*

• * CEC documentation says we must not call cec_delete_adapter
  

• * after a successful call to cec_register_adapter().
  

• */
  

• devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
• cec_register_cec_notifier(cec->adap, cec->notify);
• return 0;

+}

+static int dw_hdmi_cec_remove(struct platform_device *pdev) +{

• struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
• cec_unregister_adapter(cec->adap);
• cec_notifier_put(cec->notify);
• return 0;

+}

+static struct platform_driver dw_hdmi_cec_driver = {

• .probe = dw_hdmi_cec_probe,
• .remove = dw_hdmi_cec_remove,
• .driver = {

• .name = "dw-hdmi-cec",
  

• },

+}; +module_platform_driver(dw_hdmi_cec_driver);

+MODULE_AUTHOR("Russell King rmk+kernel@armlinux.org.uk"); +MODULE_DESCRIPTION("Synopsis Designware HDMI CEC driver for i.MX"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec"); diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h new file mode 100644 index 000000000000..cf4dc121a2c4 --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h @@ -0,0 +1,19 @@ +#ifndef DW_HDMI_CEC_H +#define DW_HDMI_CEC_H

+struct dw_hdmi;

+struct dw_hdmi_cec_ops {

• void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
• u8 (*read)(struct dw_hdmi *hdmi, int offset);
• void (*enable)(struct dw_hdmi *hdmi);
• void (*disable)(struct dw_hdmi *hdmi);

+};

+struct dw_hdmi_cec_data {

• struct dw_hdmi *hdmi;
• const struct dw_hdmi_cec_ops *ops;
• int irq;

+};

+#endif diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 58781d4c1034..5a389f1f58d9 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -35,6 +35,7 @@

#include "dw-hdmi.h" #include "dw-hdmi-audio.h" +#include "dw-hdmi-cec.h"

#include <media/cec-notifier.h>

@@ -133,6 +134,7 @@ struct dw_hdmi { unsigned int version;

struct platform_device *audio;

• struct platform_device *cec; struct device *dev; struct clk *isfr_clk; struct clk *iahb_clk;

@@ -1766,7 +1768,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi) hdmi_writeb(hdmi, 0xff, HDMI_AUD_HBR_MASK); hdmi_writeb(hdmi, 0xff, HDMI_GP_MASK); hdmi_writeb(hdmi, 0xff, HDMI_A_APIINTMSK);

• hdmi_writeb(hdmi, 0xff, HDMI_CEC_MASK); hdmi_writeb(hdmi, 0xff, HDMI_I2CM_INT); hdmi_writeb(hdmi, 0xff, HDMI_I2CM_CTLINT);

@@ -2223,6 +2224,29 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi) return -ENODEV; }

+static void dw_hdmi_cec_enable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static void dw_hdmi_cec_disable(struct dw_hdmi *hdmi) +{

• mutex_lock(&hdmi->mutex);
• hdmi->mc_clkdis |= HDMI_MC_CLKDIS_CECCLK_DISABLE;
• hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
• mutex_unlock(&hdmi->mutex);

+}

+static const struct dw_hdmi_cec_ops dw_hdmi_cec_ops = {

• .write = hdmi_writeb,
• .read = hdmi_readb,
• .enable = dw_hdmi_cec_enable,
• .disable = dw_hdmi_cec_disable,

+};

static const struct regmap_config hdmi_regmap_8bit_config = { .reg_bits = 32, .val_bits = 8, @@ -2245,6 +2269,7 @@ __dw_hdmi_probe(struct platform_device *pdev, struct device_node *np = dev->of_node; struct platform_device_info pdevinfo; struct device_node *ddc_node;

• struct dw_hdmi_cec_data cec; struct dw_hdmi *hdmi; struct resource *iores = NULL; int irq;

@@ -2445,6 +2470,17 @@ __dw_hdmi_probe(struct platform_device *pdev, hdmi->audio = platform_device_register_full(&pdevinfo); }

• cec.hdmi = hdmi;
• cec.ops = &dw_hdmi_cec_ops;
• cec.irq = irq;
• pdevinfo.name = "dw-hdmi-cec";
• pdevinfo.data = &cec;
• pdevinfo.size_data = sizeof(cec);
• pdevinfo.dma_mask = 0;
• hdmi->cec = platform_device_register_full(&pdevinfo);

Maybe you should check the config bit before enabling CEC :

/* CONFIG0_ID field values */ + HDMI_CONFIG0_CEC = 0x2,

if (config0 & HDMI_CONFIG0_CEC) { }

• /* Reset HDMI DDC I2C master controller and mute I2CM interrupts */ if (hdmi->i2c) dw_hdmi_i2c_init(hdmi);

@@ -2475,6 +2511,8 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi) { if (hdmi->audio && !IS_ERR(hdmi->audio)) platform_device_unregister(hdmi->audio);

• if (!IS_ERR(hdmi->cec))

• platform_device_unregister(hdmi->cec);
  
  

  /* Disable all interrupts */ hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);

Apart from that and the s/Synopsis/Synopsys/ typos:

Reviewed-by: Neil Armstrong narmstrong@baylibre.com

Neil

Hi Hans,

On 02-06-2017 07:31, Hans Verkuil wrote:

On 06/01/2017 03:47 PM, Neil Armstrong wrote:

...

On 05/30/2017 04:23 PM, Russell King wrote:

...

Add a CEC driver for the dw-hdmi hardware.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/Kconfig | 8 + drivers/gpu/drm/bridge/synopsys/Makefile | 1 + drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 320 ++++++++++++++++++++++++++ drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h | 19 ++ drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++- 5 files changed, 387 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h

diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig index 40d2827a6d19..bd30a0a07272 100644 --- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO help Support the I2S Audio interface which is part of the Synopsys Designware HDMI block.

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
• select MEDIA_CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

•  Designware HDMI block.
  

diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile index 17aa7a65b57e..6fe415903668 100644 --- a/drivers/gpu/drm/bridge/synopsys/Makefile +++ b/drivers/gpu/drm/bridge/synopsys/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o +obj-$(CONFIG_DRM_DW_HDMI_CEC) += dw-hdmi-cec.o diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c new file mode 100644 index 000000000000..761ef5ae687d --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c @@ -0,0 +1,320 @@ +/*

• • Designware HDMI CEC driver
• • Copyright (C) 2015-2017 Russell King.
• • This program is free software; you can redistribute it

and/or modify

• • it under the terms of the GNU General Public License

version 2 as

• • published by the Free Software Foundation.
• */

+#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h>

+#include <drm/drm_edid.h>

+#include <media/cec.h> +#include <media/cec-notifier.h>

+#include "dw-hdmi-cec.h"

+enum {

• HDMI_IH_CEC_STAT0 = 0x0106,
• HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
• HDMI_CEC_CTRL = 0x7d00,
• CEC_CTRL_START = BIT(0),
• CEC_CTRL_NORMAL = 1 << 1,
• HDMI_CEC_STAT = 0x7d01,
• CEC_STAT_DONE = BIT(0),
• CEC_STAT_EOM = BIT(1),
• CEC_STAT_NACK = BIT(2),
• CEC_STAT_ARBLOST = BIT(3),
• CEC_STAT_ERROR_INIT = BIT(4),
• CEC_STAT_ERROR_FOLL = BIT(5),
• CEC_STAT_WAKEUP = BIT(6),

I hadn't realized until Jose Abreu's latest reply, but you need to check the ARBLOST status and set the TX state to CEC_TX_STATUS_ARB_LOST.

I think CEC_STAT_ERROR_FOLL might equal CEC_TX_STATUS_LOW_DRIVE, but without documentation I can't be sure.

My experience is that this low drive condition tends to be poorly reported by hardware. Either that or poorly documented. This is why I added a CEC_TX_STATUS_ERROR status as a catch-all error status when it is unclear from the hardware/documentation what error occurred.

Jose, do you know which status bit is used to report a follower pulling the CEC line low for a long time (approx. 3.6 ms) to signal a CEC error?

Bit 5 for follower error, bit 4 for initiator error.

Best regards, Jose Miguel Abreu

Regards,

Hans

On Fri, Jun 02, 2017 at 11:06:24AM +0200, Hans Verkuil wrote:

On 06/02/17 08:43, Jose Abreu wrote:

...

Hi Hans,

On 02-06-2017 07:31, Hans Verkuil wrote:

...

On 06/01/2017 03:47 PM, Neil Armstrong wrote:

...

On 05/30/2017 04:23 PM, Russell King wrote:

...

Add a CEC driver for the dw-hdmi hardware.

Signed-off-by: Russell King rmk+kernel@armlinux.org.uk

drivers/gpu/drm/bridge/synopsys/Kconfig | 8 + drivers/gpu/drm/bridge/synopsys/Makefile | 1 + drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 320 ++++++++++++++++++++++++++ drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h | 19 ++ drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++- 5 files changed, 387 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h

diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig index 40d2827a6d19..bd30a0a07272 100644 --- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO help Support the I2S Audio interface which is part of the Synopsys Designware HDMI block.

+config DRM_DW_HDMI_CEC

• tristate "Synopsis Designware CEC interface"
• depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
• select MEDIA_CEC_NOTIFIER
• help

•  Support the CE interface which is part of the Synopsis
  

•  Designware HDMI block.
  

diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile index 17aa7a65b57e..6fe415903668 100644 --- a/drivers/gpu/drm/bridge/synopsys/Makefile +++ b/drivers/gpu/drm/bridge/synopsys/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o +obj-$(CONFIG_DRM_DW_HDMI_CEC) += dw-hdmi-cec.o diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c new file mode 100644 index 000000000000..761ef5ae687d --- /dev/null +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c @@ -0,0 +1,320 @@ +/*

• • Designware HDMI CEC driver
• • Copyright (C) 2015-2017 Russell King.
• • This program is free software; you can redistribute it

and/or modify

• • it under the terms of the GNU General Public License

version 2 as

• • published by the Free Software Foundation.
• */

+#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h>

+#include <drm/drm_edid.h>

+#include <media/cec.h> +#include <media/cec-notifier.h>

+#include "dw-hdmi-cec.h"

+enum {

• HDMI_IH_CEC_STAT0 = 0x0106,
• HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
• HDMI_CEC_CTRL = 0x7d00,
• CEC_CTRL_START = BIT(0),
• CEC_CTRL_NORMAL = 1 << 1,
• HDMI_CEC_STAT = 0x7d01,
• CEC_STAT_DONE = BIT(0),
• CEC_STAT_EOM = BIT(1),
• CEC_STAT_NACK = BIT(2),
• CEC_STAT_ARBLOST = BIT(3),
• CEC_STAT_ERROR_INIT = BIT(4),
• CEC_STAT_ERROR_FOLL = BIT(5),
• CEC_STAT_WAKEUP = BIT(6),

I hadn't realized until Jose Abreu's latest reply, but you need to check the ARBLOST status and set the TX state to CEC_TX_STATUS_ARB_LOST.

I think CEC_STAT_ERROR_FOLL might equal CEC_TX_STATUS_LOW_DRIVE, but without documentation I can't be sure.

My experience is that this low drive condition tends to be poorly reported by hardware. Either that or poorly documented. This is why I added a CEC_TX_STATUS_ERROR status as a catch-all error status when it is unclear from the hardware/documentation what error occurred.

Jose, do you know which status bit is used to report a follower pulling the CEC line low for a long time (approx. 3.6 ms) to signal a CEC error?

Bit 5 for follower error, bit 4 for initiator error.

I gathered that from the define names :-)

But what does it mean? What sort of error is reported here?

I think the problem is that no one really knows, the documentation is quite poor:

5 An error is notified by a follower. Abnormal logic data ERROR_FOLL bit error (for follower). 4 An error is detected on cec line (for initiator only). ERROR_INIT

It is so vague that you can read anything into that description.