On Mon, 28 Mar 2022 11:14, AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com wrote:
Il 28/03/22 00:39, Guillaume Ranquet ha scritto:
From: Markus Schneider-Pargmann msp@baylibre.com
This patch adds a DisplayPort driver for the Mediatek mt8195 SoC.
It supports the mt8195, the embedded DisplayPort units. It offers DisplayPort 1.4 with up to 4 lanes.
The driver shares its iomap range with the mtk-dp-phy driver using the regmap/syscon facility.
This driver is based on an initial version by Jason-JH.Lin jason-jh.lin@mediatek.com.
Signed-off-by: Markus Schneider-Pargmann msp@baylibre.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com Reported-by: kernel test robot lkp@intel.com
Hello Guillaume, as you know, there's some more work to do on this driver.
I will also mention here, not on the code, that at this point, your mtk_dp_aux_transfer() function has something VERY similar to function drm_dp_dpcd_access(), so I really believe that you can instead use functions drm_dp_dpcd_read() and drm_dp_dpcd_write(), avoiding code duplication around.
Please check drivers/gpu/drm/dp/drm_dp.c.
This is already in my TODO list as this has been suggested by Rex earlier.
drivers/gpu/drm/mediatek/Kconfig | 8 + drivers/gpu/drm/mediatek/Makefile | 2 + drivers/gpu/drm/mediatek/mtk_dp.c | 2221 ++++++++++++++++++++++++ drivers/gpu/drm/mediatek/mtk_dp_reg.h | 568 ++++++ drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 + drivers/gpu/drm/mediatek/mtk_drm_drv.h | 1 + 6 files changed, 2801 insertions(+) create mode 100644 drivers/gpu/drm/mediatek/mtk_dp.c create mode 100644 drivers/gpu/drm/mediatek/mtk_dp_reg.h
diff --git a/drivers/gpu/drm/mediatek/Kconfig b/drivers/gpu/drm/mediatek/Kconfig index 2976d21e9a34..03ffa9b896c3 100644 --- a/drivers/gpu/drm/mediatek/Kconfig +++ b/drivers/gpu/drm/mediatek/Kconfig @@ -28,3 +28,11 @@ config DRM_MEDIATEK_HDMI select PHY_MTK_HDMI help DRM/KMS HDMI driver for Mediatek SoCs
+config MTK_DPTX_SUPPORT
Actually, I think that the best would be DRM_MEDIATEK_DP_TX or DRM_MEDIATEK_DP... ...also, ordering is important, please!
I will update the name. What do you mean by ordering? do you expect the configs to be ordered alphabetically?
- tristate "DRM DPTX Support for Mediatek SoCs"
- depends on DRM_MEDIATEK
- select PHY_MTK_DP
- select DRM_DP_HELPER
- help
DRM/KMS Display Port driver for Mediatek SoCs.diff --git a/drivers/gpu/drm/mediatek/Makefile b/drivers/gpu/drm/mediatek/Makefile index 29098d7c8307..d86a6406055e 100644 --- a/drivers/gpu/drm/mediatek/Makefile +++ b/drivers/gpu/drm/mediatek/Makefile @@ -21,3 +21,5 @@ mediatek-drm-hdmi-objs := mtk_cec.o \ mtk_hdmi_ddc.o
obj-$(CONFIG_DRM_MEDIATEK_HDMI) += mediatek-drm-hdmi.o
+obj-$(CONFIG_MTK_DPTX_SUPPORT) += mtk_dp.o diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c new file mode 100644 index 000000000000..7cd8459cf719 --- /dev/null +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -0,0 +1,2221 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- Copyright (c) 2019 MediaTek Inc.
- Copyright (c) 2021 BayLibre
- */
+#include <drm/drm_atomic_helper.h> +#include <drm/drm_bridge.h> +#include <drm/drm_crtc.h> +#include <drm/dp/drm_dp_helper.h> +#include <drm/drm_edid.h> +#include <drm/drm_of.h> +#include <drm/drm_panel.h> +#include <drm/drm_print.h> +#include <drm/drm_probe_helper.h> +#include <linux/arm-smccc.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/nvmem-consumer.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <sound/hdmi-codec.h> +#include <video/videomode.h>
+#include "mtk_dp_reg.h"
+#define MTK_DP_AUX_WAIT_REPLY_COUNT 20 +#define MTK_DP_CHECK_SINK_CAP_TIMEOUT_COUNT 3
+//TODO: platform/device data or dts?
Assuming that your TODO is about the maximum number of lanes, { .compatible = "mediatek,mt8195-edp-tx", .data = &some_const_structure },
Yes, exactly that, it'll be in v10.
+#define MTK_DP_MAX_LANES 4 +#define MTK_DP_MAX_LINK_RATE MTK_DP_LINKRATE_HBR3
..snip..
+static int mtk_dp_bulk_16bit_write(struct mtk_dp *mtk_dp, u32 offset, u8 *buf,
size_t length)+{
- int i;
- int ret = 0;
- int num_regs = (length + 1) / 2;
- /* 2 bytes per register */
- for (i = 0; i < num_regs; i++) {
u32 val = buf[i * 2] |(i * 2 + 1 < length ? buf[i * 2 + 1] << 8 : 0);ret = mtk_dp_write(mtk_dp, offset + i * 4, val);if (ret)goto out;if (ret) return ret;
- }
+out:
Remove this label.
- return ret;
+}
+static unsigned long mtk_dp_sip_atf_call(unsigned int cmd, unsigned int para) +{
- struct arm_smccc_res res;
- arm_smccc_smc(MTK_DP_SIP_CONTROL_AARCH32, cmd, para, 0, 0, 0, 0, 0,
&res);- pr_debug("[DPTX]%s cmd 0x%x, p1 0x%x, ret 0x%lx-0x%lx", __func__, cmd,
para, res.a0, res.a1);- return res.a1;
+}
+static int mtk_dp_msa_bypass_disable(struct mtk_dp *mtk_dp) +{
- const u16 bits_to_set =
BIT(HTOTAL_SEL_DP_ENC0_P0_SHIFT) |BIT(VTOTAL_SEL_DP_ENC0_P0_SHIFT) |BIT(HSTART_SEL_DP_ENC0_P0_SHIFT) |BIT(VSTART_SEL_DP_ENC0_P0_SHIFT) |BIT(HWIDTH_SEL_DP_ENC0_P0_SHIFT) |BIT(VHEIGHT_SEL_DP_ENC0_P0_SHIFT) |BIT(HSP_SEL_DP_ENC0_P0_SHIFT) | BIT(HSW_SEL_DP_ENC0_P0_SHIFT) |BIT(VSP_SEL_DP_ENC0_P0_SHIFT) | BIT(VSW_SEL_DP_ENC0_P0_SHIFT);- return mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3030, bits_to_set,
bits_to_set);+}
+#define MTK_UPD_BITS_OR_OUT(mtk_dp, offset, val, mask, ret, label) \
- do {\
ret = mtk_dp_update_bits(mtk_dp, offset, val, mask); \if (ret) \goto label; \- } while (0)
I'm sorry, no offense - but this macro is a bit ugly...
I think I understand why you have introduced it, but in my opinion this decreases human readability a lot, I was even about to point out multiple functions that you had unused labels before checking this macro, as that was totally unexpected...
In my opinion, this should be open-coded everywhere... yes it makes the file a bit fatter in terms of amount of text, but eh... it's life :)))
No offense taken... I find the macro ugly too... but I couldn't think of anything less ugly... I'll bite the bullet and write all of the code then.
....snip....
+static int mtk_dp_set_color_format(struct mtk_dp *mtk_dp,
enum mtk_dp_color_format color_format)+{
- u32 val;
- int ret;
- mtk_dp->info.format = color_format;
- /* Update MISC0 */
- ret = mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3034,
color_format << DP_TEST_COLOR_FORMAT_SHIFT,DP_TEST_COLOR_FORMAT_MASK);- if (ret)
return ret;- switch (color_format) {
- case MTK_DP_COLOR_FORMAT_YUV_422:
val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_YCBCR422;break;- case MTK_DP_COLOR_FORMAT_YUV_420:
val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_YCBCR420;break;- case MTK_DP_COLOR_FORMAT_YONLY:
- case MTK_DP_COLOR_FORMAT_RAW:
- case MTK_DP_COLOR_FORMAT_RESERVED:
- case MTK_DP_COLOR_FORMAT_UNKNOWN:
drm_warn(mtk_dp->drm_dev, "Unsupported color format: %d\n",color_format);fallthrough;Uhm, are you sure that you should fallthrough? If we get a color format that we don't understand, the best thing that would happen is that we'd get scrambled colors... which is something unwanted.
The best idea is to return -EINVAL here, hence refuse to go on with an invalid color format.
Will do.
- case MTK_DP_COLOR_FORMAT_RGB_444:
- case MTK_DP_COLOR_FORMAT_YUV_444:
val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_RGB;break;- }
- return mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_303C, val,
PIXEL_ENCODE_FORMAT_DP_ENC0_P0_MASK);+}
...snip...
+static void mtk_dp_initialize_hpd_detect_settings(struct mtk_dp *mtk_dp) +{
- // Debounce threshold
I think I already told you to fix comments style.
- mtk_dp_update_bits(mtk_dp, MTK_DP_TRANS_P0_3410,
8 << HPD_DEB_THD_DP_TRANS_P0_SHIFT,HPD_DEB_THD_DP_TRANS_P0_MASK);- mtk_dp_update_bits(mtk_dp, MTK_DP_TRANS_P0_3410,
(HPD_INT_THD_DP_TRANS_P0_LOWER_500US |HPD_INT_THD_DP_TRANS_P0_UPPER_1100US)<< HPD_INT_THD_DP_TRANS_P0_SHIFT,HPD_INT_THD_DP_TRANS_P0_MASK);- // Connect threshold 1.5ms + 5 x 0.1ms = 2ms
- // Disconnect threshold 1.5ms + 5 x 0.1ms = 2ms
- mtk_dp_update_bits(mtk_dp, MTK_DP_TRANS_P0_3410,
(5 << HPD_DISC_THD_DP_TRANS_P0_SHIFT) |(5 << HPD_CONN_THD_DP_TRANS_P0_SHIFT),HPD_DISC_THD_DP_TRANS_P0_MASK |HPD_CONN_THD_DP_TRANS_P0_MASK);- mtk_dp_update_bits(mtk_dp, MTK_DP_TRANS_P0_3430,
HPD_INT_THD_ECO_DP_TRANS_P0_HIGH_BOUND_EXT,HPD_INT_THD_ECO_DP_TRANS_P0_MASK);+}
..snip..
+static int mtk_dp_power_disable(struct mtk_dp *mtk_dp) +{
- int ret;
- ret = mtk_dp_write(mtk_dp, MTK_DP_TOP_PWR_STATE, 0);
- if (ret)
goto out;- usleep_range(10, 200);
- ret = mtk_dp_write(mtk_dp, MTK_DP_0034,
DA_CKM_CKTX0_EN_FORCE_EN | DA_CKM_BIAS_LPF_EN_FORCE_VAL |DA_CKM_BIAS_EN_FORCE_VAL |DA_XTP_GLB_LDO_EN_FORCE_VAL |DA_XTP_GLB_AVD10_ON_FORCE_VAL);- if (ret)
goto out;- /* Disable RX */
- ret = mtk_dp_write(mtk_dp, MTK_DP_1040, 0);
- if (ret)
goto out;- ret = mtk_dp_write(mtk_dp, MTK_DP_TOP_MEM_PD,
0x550 | BIT(FUSE_SEL_SHIFT) | BIT(MEM_ISO_EN_SHIFT));+out:
You are using a goto instead of a return, but you're not reverting any change, so this goto usage is not justified - hence, wrong.
Please simply return ret when anything fails, and return 0 at the end of this function.
....... (blahblah function code)
ret = something() if (ret) return ret;
return 0; }
- return ret;
+}
...snip...
I'll remove all the gotos that have no unwrapping then.
+static int mtk_dp_dt_parse(struct mtk_dp *mtk_dp,
struct platform_device *pdev)+{
- struct device *dev = &pdev->dev;
- int ret = 0;
- void __iomem *base;
- base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(base))
return PTR_ERR(base);- mtk_dp->regs = syscon_node_to_regmap(dev->of_node);
- if (IS_ERR(mtk_dp->regs))
return PTR_ERR(mtk_dp->regs);- //TODO: optional clock?
Well, if it's optional, you should use devm_clk_get_optional(), meaning that......
- mtk_dp->dp_tx_clk = devm_clk_get(dev, "faxi");
- if (IS_ERR(mtk_dp->dp_tx_clk)) {
ret = PTR_ERR(mtk_dp->dp_tx_clk);dev_info(dev, "Failed to get dptx clock: %d\n", ret);mtk_dp->dp_tx_clk = NULL;...I shouldn't see this snippet of code, as it should be a bit different... :)
It is still unclear to me if this should be optional or not, hence the 'TODO'
- }
- return 0;
+}
..snip..
+static void mtk_dp_bridge_atomic_disable(struct drm_bridge *bridge,
struct drm_bridge_state *old_state)+{
- struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
- mtk_dp_video_mute(mtk_dp, true);
- mtk_dp->state = MTK_DP_STATE_IDLE;
- mtk_dp->train_state = MTK_DP_TRAIN_STATE_STARTUP;
- mtk_dp->enabled = false;
- msleep(100);
100 milliseconds is an eternity, why are we sleeping for *so long* here?
Please, either add a comment that fully explains the resons for that, or remove the sleep entirely: to my eyes, it doesn't look like this sleep is really needed for anything important because here you are disabling the bridge and *powering off* the IP entirely.
This sleep can be removed. I will also make an effort to document all the other delays in the code for v10.
- mtk_dp_poweroff(mtk_dp);
+}
..snip..
+static enum drm_mode_status +mtk_dp_bridge_mode_valid(struct drm_bridge *bridge,
const struct drm_display_info *info,const struct drm_display_mode *mode)+{
- struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
- u32 rx_linkrate = (u32)mtk_dp->train_info.link_rate * 27000;
- u32 bpp = info->color_formats & DRM_COLOR_FORMAT_YCBCR422 ? 16 : 24;
- if (rx_linkrate * mtk_dp->train_info.lane_count < mode->clock * bpp / 8)
return MODE_CLOCK_HIGH;- if (mode->clock > 600000)
return MODE_CLOCK_HIGH;- //TODO: explain magic number: 62?
Please fix this TODO for v10.
- if ((mode->clock * 1000) / (mode->htotal * mode->vtotal) > 62)
return MODE_CLOCK_HIGH;- return MODE_OK;
+}
Thx a lot for your review, Guillaume.