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 SynopsisDesignware 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?
Regards,
Hans