[PATCH 3/3] [RFC] drm/exynos: Add basic i.MX8MM support code

Michael Tretter m.tretter at pengutronix.de
Wed Feb 3 19:53:39 UTC 2021


On Mon, 05 Oct 2020 15:42:50 +0200, Marek Vasut wrote:
> This adds basic i.MX8MM glue code for the Samsung DSIM PHY.
> There are still a couple of items which need to be sorted out
> in drivers/gpu/drm/bridge/samsung-dsim.c before this can even
> be merged, specifically:
> 
> - The dsi->out_bridge is not populated until samsung_dsim_host_attach()
>   is called, however samsung_dsim_host_attach() is not called until the
>   next bridge attaches and calls mipi_dsi_attach(), and that only happens
>   after the DSIM calls drm_bridge_attach() on that next bridge.

IMO, the DSIM behaves correctly by calling drm_bridge_attach() only after
samsung_dsim_host_attach() was called. At this point some DSI device has
appeared and told the DSI host that it is the next bridge in the pipeline.

Other DRI host bridges that I looked at behave the same. Either deferring the
bridge_attach until a DSI device has attached or even adding the bridge only
after a DSI device has attached. If a DSI device behaves differently, the DSI
device should be fixed to attach during probe instead of during bridge_attach.

> 
> - The samsung_dsim_bridge_mode_fixup() is needed for iMX8MM LCDIF to set
>   the correct sync flags. This likely needs to be done in the glue code.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Guido Günther <agx at sigxcpu.org>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Cc: Marek Szyprowski <m.szyprowski at samsung.com>
> Cc: Michael Tretter <m.tretter at pengutronix.de>
> Cc: NXP Linux Team <linux-imx at nxp.com>
> Cc: Shawn Guo <shawnguo at kernel.org>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-samsung-soc at vger.kernel.org
> To: dri-devel at lists.freedesktop.org
> --
> NOTE: This depends on https://patchwork.kernel.org/project/dri-devel/list/?series=347439
> ---
>  drivers/gpu/drm/bridge/Kconfig            |   6 +
>  drivers/gpu/drm/bridge/Makefile           |   1 +
>  drivers/gpu/drm/bridge/samsung-dsim-imx.c | 161 ++++++++++++++++++++++
>  drivers/gpu/drm/bridge/samsung-dsim.c     |  25 +++-
>  4 files changed, 192 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/bridge/samsung-dsim-imx.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 2d4459f78cdc..f97a8ebfcef1 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -129,6 +129,12 @@ config DRM_SAMSUNG_DSIM
>  	help
>  	  Samsung MIPI DSI bridge driver.
>  
> +config DRM_SAMSUNG_DSIM_IMX
> +	tristate "Samsung MIPI DSI bridge extras for NXP i.MX"
> +	depends on DRM_SAMSUNG_DSIM
> +	help
> +	  Samsung MIPI DSI bridge driver extras for NXP i.MX.
> +
>  config DRM_SIL_SII8620
>  	tristate "Silicon Image SII8620 HDMI/MHL bridge"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index f7972d703c5d..61188a0cd052 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
>  obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
>  obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
>  obj-$(CONFIG_DRM_SAMSUNG_DSIM) += samsung-dsim.o
> +obj-$(CONFIG_DRM_SAMSUNG_DSIM_IMX) += samsung-dsim-imx.o
>  obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o
>  obj-$(CONFIG_DRM_SII902X) += sii902x.o
>  obj-$(CONFIG_DRM_SII9234) += sii9234.o
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim-imx.c b/drivers/gpu/drm/bridge/samsung-dsim-imx.c
> new file mode 100644
> index 000000000000..6c7307ce7eaf
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/samsung-dsim-imx.c
> @@ -0,0 +1,161 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * NXP i.MX8M SoC MIPI DSI driver
> + *
> + * Copyright (C) 2020 Marek Vasut <marex at denx.de>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <drm/bridge/samsung-dsim.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_encoder.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_probe_helper.h>
> +#include <drm/drm_simple_kms_helper.h>
> +
> +enum {
> +	DSI_PORT_IN,
> +	DSI_PORT_OUT
> +};
> +
> +struct imx_dsim_priv {
> +	struct samsung_dsim *dsi;
> +	struct drm_encoder encoder;
> +};
> +
> +static const unsigned int imx8mm_dsim_reg_values[] = {
> +	[RESET_TYPE] = DSIM_SWRST,
> +	[PLL_TIMER] = 500,
> +	[STOP_STATE_CNT] = 0xf,
> +	[PHYCTRL_ULPS_EXIT] = 0xaf,
> +	[PHYCTRL_VREG_LP] = 0,
> +	[PHYCTRL_SLEW_UP] = 0,
> +	[PHYTIMING_LPX] = 0x06,
> +	[PHYTIMING_HS_EXIT] = 0x0b,
> +	[PHYTIMING_CLK_PREPARE] = 0x07,
> +	[PHYTIMING_CLK_ZERO] = 0x26,
> +	[PHYTIMING_CLK_POST] = 0x0d,
> +	[PHYTIMING_CLK_TRAIL] = 0x08,
> +	[PHYTIMING_HS_PREPARE] = 0x08,
> +	[PHYTIMING_HS_ZERO] = 0x0d,
> +	[PHYTIMING_HS_TRAIL] = 0x0b,
> +};
> +
> +static int imx_dsim_host_attach(struct device *dev,
> +				  struct mipi_dsi_device *device)
> +{
> +	struct imx_dsim_priv *dsi = dev_get_drvdata(dev);
> +	struct drm_device *drm = dsi->encoder.dev;
> +
> +	if (drm->mode_config.poll_enabled)
> +		drm_kms_helper_hotplug_event(drm);
> +
> +	return 0;
> +}
> +
> +static int imx_dsim_host_detach(struct device *dev,
> +				  struct mipi_dsi_device *device)
> +{
> +	struct imx_dsim_priv *dsi = dev_get_drvdata(dev);
> +	struct drm_device *drm = dsi->encoder.dev;
> +
> +	if (drm->mode_config.poll_enabled)
> +		drm_kms_helper_hotplug_event(drm);
> +
> +	return 0;
> +}
> +
> +static const struct samsung_dsim_host_ops imx_dsim_host_ops = {
> +	.attach = imx_dsim_host_attach,
> +	.detach = imx_dsim_host_detach,
> +};
> +
> +static const struct samsung_dsim_driver_data imx8mm_dsi_driver_data = {
> +	.reg_ofs = EXYNOS5433_REG_OFS,
> +	.plltmr_reg = 0xa0,
> +	.has_clklane_stop = 1,
> +	.num_clks = 2,
> +	.max_freq = 2100,
> +	.wait_for_reset = 0,
> +	.num_bits_resol = 12,
> +	.reg_values = imx8mm_dsim_reg_values,
> +	.host_ops = &imx_dsim_host_ops,
> +};
> +
> +static const struct of_device_id imx_dsim_of_match[] = {
> +	{ .compatible = "fsl,imx8mm-mipi-dsim",
> +	  .data = &imx8mm_dsi_driver_data },
> +	{ }
> +};
> +
> +static int imx_dsim_probe(struct platform_device *pdev)
> +{
> +	struct imx_dsim_priv *dsi;
> +	struct device *dev = &pdev->dev;
> +
> +	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> +	if (!dsi)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, dsi);
> +
> +	dsi->dsi = samsung_dsim_probe(pdev);
> +	if (IS_ERR(dsi->dsi))
> +		return PTR_ERR(dsi->dsi);
> +
> +	pm_runtime_enable(dev);
> +
> +	return 0;
> +}
> +
> +static int imx_dsim_remove(struct platform_device *pdev)
> +{
> +	struct imx_dsim_priv *dsi = platform_get_drvdata(pdev);
> +
> +	pm_runtime_disable(&pdev->dev);
> +
> +	samsung_dsim_remove(dsi->dsi);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx_dsim_suspend(struct device *dev)
> +{
> +	struct imx_dsim_priv *dsi = dev_get_drvdata(dev);
> +
> +	return samsung_dsim_suspend(dsi->dsi);
> +}
> +
> +static int __maybe_unused imx_dsim_resume(struct device *dev)
> +{
> +	struct imx_dsim_priv *dsi = dev_get_drvdata(dev);
> +
> +	return samsung_dsim_resume(dsi->dsi);
> +}
> +
> +static const struct dev_pm_ops imx_dsim_pm_ops = {
> +	SET_RUNTIME_PM_OPS(imx_dsim_suspend, imx_dsim_resume, NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				pm_runtime_force_resume)
> +};
> +
> +static struct platform_driver imx_dsim_driver = {
> +	.probe = imx_dsim_probe,
> +	.remove = imx_dsim_remove,
> +	.driver = {
> +		   .name = "imx-dsim-dsi",
> +		   .owner = THIS_MODULE,
> +		   .pm = &imx_dsim_pm_ops,
> +		   .of_match_table = imx_dsim_of_match,
> +	},
> +};
> +
> +module_platform_driver(imx_dsim_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marex at denx.de>");
> +MODULE_DESCRIPTION("NXP i.MX8M SoC MIPI DSI");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 42b49546dd00..12aeceb40450 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -28,6 +28,7 @@
>  #include <drm/drm_bridge.h>
>  #include <drm/drm_fb_helper.h>
>  #include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_of.h>
>  #include <drm/drm_panel.h>
>  #include <drm/drm_print.h>
>  #include <drm/drm_probe_helper.h>
> @@ -1388,8 +1389,15 @@ static int samsung_dsim_bridge_attach(struct drm_bridge *bridge,
>  {
>  	struct samsung_dsim *dsi = bridge->driver_private;
>  	struct drm_encoder *encoder = bridge->encoder;
> +	struct device *dev = dsi->dev;
> +	struct device_node *np = dev->of_node;
>  	int ret;
>  
> +	ret = drm_of_find_panel_or_bridge(np, 1, 0,
> +					  &dsi->panel, &dsi->out_bridge);
> +	if (ret)
> +		return ret;
> +
>  	if (!dsi->out_bridge && !dsi->panel)
>  		return -EPROBE_DEFER;
>  
> @@ -1398,7 +1406,6 @@ static int samsung_dsim_bridge_attach(struct drm_bridge *bridge,
>  					bridge, flags);
>  		if (ret)
>  			return ret;
> -		list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);
>  	} else {
>  		ret = samsung_dsim_create_connector(dsi);
>  		if (ret)
> @@ -1456,18 +1463,31 @@ static void samsung_dsim_bridge_mode_set(struct drm_bridge *bridge,
>  	drm_mode_copy(&dsi->mode, adjusted_mode);
>  }
>  
> +static bool samsung_dsim_bridge_mode_fixup(struct drm_bridge *bridge,
> +					   const struct drm_display_mode *mode,
> +					   struct drm_display_mode *adjusted_mode)
> +{
> +	/* At least LCDIF + DSIM needs active low sync */
> +	adjusted_mode->flags |= (DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
> +	adjusted_mode->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
> +
> +	return true;
> +}
> +
>  static const struct drm_bridge_funcs samsung_dsim_bridge_funcs = {
>  	.attach = samsung_dsim_bridge_attach,
>  	.detach = samsung_dsim_bridge_detach,
>  	.enable = samsung_dsim_bridge_enable,
>  	.disable = samsung_dsim_bridge_disable,
>  	.mode_set = samsung_dsim_bridge_mode_set,
> +	.mode_fixup = samsung_dsim_bridge_mode_fixup,
>  };
>  
>  static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
>  				    struct mipi_dsi_device *device)
>  {
>  	struct samsung_dsim *dsi = host_to_dsi(host);
> +#if 0
>  	const struct samsung_dsim_host_ops *ops = dsi->driver_data->host_ops;
>  	struct drm_bridge *out_bridge;
>  
> @@ -1493,13 +1513,16 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
>  		if (ret)
>  			return ret;
>  	}
> +#endif
>  
>  	dsi->lanes = device->lanes;
>  	dsi->format = device->format;
>  	dsi->mode_flags = device->mode_flags;
>  
> +#if 0
>  	if (ops && ops->attach)
>  		ops->attach(dsi->dsi_host.dev, device);
> +#endif
>  
>  	return 0;
>  }
> -- 
> 2.28.0
> 
> 


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