[PATCH 2/4] drm/imx: add bridge wrapper driver for i.MX8MP DWC HDMI
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Fri Aug 26 19:49:24 UTC 2022
Hi Lucas,
Thank you for the patch.
On Fri, Aug 26, 2022 at 09:24:22PM +0200, Lucas Stach wrote:
> Add a simple wrapper driver for the DWC HDMI bridge driver that
> implements the few bits that are necessary to abstract the i.MX8MP
> SoC integration.
>
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> Tested-by: Marek Vasut <marex at denx.de>
> ---
> drivers/gpu/drm/bridge/imx/Kconfig | 9 ++
> drivers/gpu/drm/bridge/imx/Makefile | 2 +
> drivers/gpu/drm/bridge/imx/imx8mp-hdmi.c | 141 +++++++++++++++++++++++
> 3 files changed, 152 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/imx/imx8mp-hdmi.c
>
> diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
> index 608f47f41bcd..d828d8bfd893 100644
> --- a/drivers/gpu/drm/bridge/imx/Kconfig
> +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> @@ -44,4 +44,13 @@ config DRM_IMX8QXP_PIXEL_LINK_TO_DPI
> Choose this to enable pixel link to display pixel interface(PXL2DPI)
> found in Freescale i.MX8qxp processor.
>
> +config DRM_IMX8MP_DW_HDMI_BRIDGE
> + tristate "i.MX8MP HDMI bridge support"
> + depends on OF
> + depends on COMMON_CLK
> + select DRM_DW_HDMI
> + help
> + Choose this to enable support for the internal HDMI encoder found
> + on the i.MX8MP SoC.
> +
> endif # ARCH_MXC || COMPILE_TEST
> diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
> index aa90ec8d5433..03b0074ae538 100644
> --- a/drivers/gpu/drm/bridge/imx/Makefile
> +++ b/drivers/gpu/drm/bridge/imx/Makefile
> @@ -7,3 +7,5 @@ obj-$(CONFIG_DRM_IMX8QXP_LDB) += imx8qxp-ldb.o
> obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
> obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
> obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK_TO_DPI) += imx8qxp-pxl2dpi.o
> +
> +obj-$(CONFIG_DRM_IMX8MP_DW_HDMI_BRIDGE) += imx8mp-hdmi.o
> diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi.c b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi.c
> new file mode 100644
> index 000000000000..66089bc690c8
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi.c
> @@ -0,0 +1,141 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Copyright (C) 2022 Pengutronix, Lucas Stach <kernel at pengutronix.de>
> + */
> +
> +#include <drm/bridge/dw_hdmi.h>
> +#include <drm/drm_modes.h>
> +#include <linux/clk.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +struct imx_hdmi {
The driver is specific to the i.MX8MP, so I'd name the structure
imx8mp_hdmi. Same for the probe and remove functions and for
imx_dw_hdmi_of_table.
> + struct dw_hdmi_plat_data plat_data;
> + struct dw_hdmi *dw_hdmi;
> + struct clk *pixclk;
> + struct clk *fdcc;
> +};
> +
> +static enum drm_mode_status
> +imx8mp_hdmi_mode_valid(struct dw_hdmi *dw_hdmi, void *data,
> + const struct drm_display_info *info,
> + const struct drm_display_mode *mode)
> +{
> + struct imx_hdmi *hdmi = (struct imx_hdmi *)data;
> +
> + if (mode->clock < 13500)
> + return MODE_CLOCK_LOW;
> +
> + if (mode->clock > 297000)
> + return MODE_CLOCK_HIGH;
> +
> + if (clk_round_rate(hdmi->pixclk, mode->clock * 1000) !=
> + mode->clock * 1000)
> + return MODE_CLOCK_RANGE;
I wonder if we need some tolerance here. It can be done later.
> +
> + /* We don't support double-clocked and Interlaced modes */
> + if ((mode->flags & DRM_MODE_FLAG_DBLCLK) ||
> + (mode->flags & DRM_MODE_FLAG_INTERLACE))
> + return MODE_BAD;
> +
> + return MODE_OK;
> +}
> +
> +static int imx8mp_hdmi_phy_init(struct dw_hdmi *dw_hdmi, void *data,
> + const struct drm_display_info *display,
> + const struct drm_display_mode *mode)
> +{
> + return 0;
> +}
> +
> +static void imx8mp_hdmi_phy_disable(struct dw_hdmi *dw_hdmi, void *data)
> +{
> +}
> +
> +static const struct dw_hdmi_phy_ops imx8mp_hdmi_phy_ops = {
> + .init = imx8mp_hdmi_phy_init,
> + .disable = imx8mp_hdmi_phy_disable,
> + .read_hpd = dw_hdmi_phy_read_hpd,
> + .update_hpd = dw_hdmi_phy_update_hpd,
> + .setup_hpd = dw_hdmi_phy_setup_hpd,
> +};
> +
> +static int imx_dw_hdmi_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct dw_hdmi_plat_data *plat_data;
> + struct imx_hdmi *hdmi;
> + int ret;
> +
> + hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL);
> + if (!hdmi)
> + return -ENOMEM;
> +
> + plat_data = &hdmi->plat_data;
> +
> + hdmi->pixclk = devm_clk_get(dev, "pix");
> + if (IS_ERR(hdmi->pixclk))
> + return dev_err_probe(dev, PTR_ERR(hdmi->pixclk),
> + "Unable to get pixel clock\n");
> +
> + hdmi->fdcc = devm_clk_get(dev, "fdcc");
> + if (IS_ERR(hdmi->fdcc))
> + return dev_err_probe(dev, PTR_ERR(hdmi->fdcc),
> + "Unable to get FDCC clock\n");
> +
> + ret = clk_prepare_enable(hdmi->fdcc);
Any chance to handle this through runtime PM (or through something else,
depending on what the clock is) to avoid leaving it enabled all the time
?
> + if (ret)
> + return dev_err_probe(dev, ret, "Unable to enable FDCC clock\n");
> +
> + plat_data->mode_valid = imx8mp_hdmi_mode_valid;
> + plat_data->phy_ops = &imx8mp_hdmi_phy_ops;
> + plat_data->phy_name = "SAMSUNG HDMI TX PHY";
> + plat_data->priv_data = hdmi;
> +
> + hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
> + if (IS_ERR(hdmi->dw_hdmi))
You need to disable the fdcc clock here.
> + return PTR_ERR(hdmi->dw_hdmi);
> +
> + /*
> + * Just release PHY core from reset, all other power management is done
> + * by the PHY driver.
> + */
> + dw_hdmi_phy_gen1_reset(hdmi->dw_hdmi);
Any risk of race condition where the PHY wouldn't be released out of
reset before the HDMI bridge is used, as you call dw_hdmi_probe() first
?
> +
> + platform_set_drvdata(pdev, hdmi);
> +
> + return 0;
> +}
> +
> +static int imx_dw_hdmi_remove(struct platform_device *pdev)
> +{
> + struct imx_hdmi *hdmi = platform_get_drvdata(pdev);
> +
> + dw_hdmi_remove(hdmi->dw_hdmi);
> +
> + clk_disable_unprepare(hdmi->fdcc);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id imx_dw_hdmi_of_table[] = {
> + { .compatible = "fsl,imx8mp-hdmi" },
> + { /* Sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, imx_dw_hdmi_of_table);
> +
> +static struct platform_driver im_dw_hdmi_platform_driver = {
This one is even missing the x from imx :-)
imxmp_dw_hdmi_platform_driver for coherency with the rest.
> + .probe = imx_dw_hdmi_probe,
> + .remove = imx_dw_hdmi_remove,
> + .driver = {
> + .name = "imx-dw-hdmi",
> + .of_match_table = imx_dw_hdmi_of_table,
> + },
> +};
> +
> +module_platform_driver(im_dw_hdmi_platform_driver);
> +
> +MODULE_DESCRIPTION("i.MX8M HDMI encoder driver");
s/i.MX8M/i.MX8MP/
With these issues addressed,
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> +MODULE_LICENSE("GPL");
--
Regards,
Laurent Pinchart
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