[PATCH v3 2/2] drm/bridge: imx: add driver for HDMI TX Parallel Video Interface

Adam Ford aford173 at gmail.com
Sun Dec 10 17:35:11 UTC 2023


On Wed, Sep 20, 2023 at 3:57 PM Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Lucas,
>
> Thank you for the patch.
>
> On Wed, Sep 20, 2023 at 07:10:09PM +0200, Lucas Stach wrote:
> > This IP block is found in the HDMI subsystem of the i.MX8MP SoC. It has a
> > full timing generator and can switch between different video sources. On
> > the i.MX8MP however the only supported source is the LCDIF. The block
> > just needs to be powered up and told about the polarity of the video
> > sync signals to act in bypass mode.
> >
> > Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> > Reviewed-by: Luca Ceresoli <luca.ceresoli at bootlin.com> (v2)
> > Tested-by: Marek Vasut <marex at denx.de> (v1)
> > Tested-by: Luca Ceresoli <luca.ceresoli at bootlin.com> (v2)
> > Tested-by: Richard Leitner <richard.leitner at skidata.com> (v2)
> > Tested-by: Frieder Schrempf <frieder.schrempf at kontron.de> (v2)
> > ---
> >  drivers/gpu/drm/bridge/imx/Kconfig           |   7 +
> >  drivers/gpu/drm/bridge/imx/Makefile          |   1 +
> >  drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c | 206 +++++++++++++++++++
> >  3 files changed, 214 insertions(+)
> >  create mode 100644 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c
> >
> > diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
> > index 9fae28db6aa7..3a4e663d922a 100644
> > --- a/drivers/gpu/drm/bridge/imx/Kconfig
> > +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> > @@ -3,6 +3,13 @@ if ARCH_MXC || COMPILE_TEST
> >  config DRM_IMX_LDB_HELPER
> >       tristate
> >
> > +config DRM_IMX8MP_HDMI_PVI
> > +     tristate "Freescale i.MX8MP HDMI PVI bridge support"
> > +     depends on OF
> > +     help
> > +       Choose this to enable support for the internal HDMI TX Parallel
> > +       Video Interface found on the Freescale i.MX8MP SoC.
> > +
> >  config DRM_IMX8QM_LDB
> >       tristate "Freescale i.MX8QM LVDS display bridge"
> >       depends on OF
> > diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
> > index 8e2ebf3399a1..be9b4f9adb50 100644
> > --- a/drivers/gpu/drm/bridge/imx/Makefile
> > +++ b/drivers/gpu/drm/bridge/imx/Makefile
> > @@ -1,4 +1,5 @@
> >  obj-$(CONFIG_DRM_IMX_LDB_HELPER) += imx-ldb-helper.o
> > +obj-$(CONFIG_DRM_IMX8MP_HDMI_PVI) += imx8mp-hdmi-pvi.o
> >  obj-$(CONFIG_DRM_IMX8QM_LDB) += imx8qm-ldb.o
> >  obj-$(CONFIG_DRM_IMX8QXP_LDB) += imx8qxp-ldb.o
> >  obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
> > diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c
> > new file mode 100644
> > index 000000000000..5ccd70c98187
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pvi.c
> > @@ -0,0 +1,206 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +
> > +/*
> > + * Copyright (C) 2022 Pengutronix, Lucas Stach <kernel at pengutronix.de>
> > + */
> > +
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_bridge.h>
> > +#include <drm/drm_crtc.h>
> > +#include <linux/bitfield.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_graph.h>
> > +#include <linux/pm_runtime.h>
> > +
> > +#define HTX_PVI_CTRL                 0x0
> > +#define  PVI_CTRL_OP_VSYNC_POL               BIT(18)
> > +#define  PVI_CTRL_OP_HSYNC_POL               BIT(17)
> > +#define  PVI_CTRL_OP_DE_POL          BIT(16)
> > +#define  PVI_CTRL_INP_VSYNC_POL              BIT(14)
> > +#define  PVI_CTRL_INP_HSYNC_POL              BIT(13)
> > +#define  PVI_CTRL_INP_DE_POL         BIT(12)
> > +#define  PVI_CTRL_MODE_MASK          GENMASK(2, 1)
> > +#define  PVI_CTRL_MODE_LCDIF         2
> > +#define  PVI_CTRL_EN                 BIT(0)
> > +
> > +struct imx8mp_hdmi_pvi {
> > +     struct drm_bridge       bridge;
> > +     struct device           *dev;
> > +     struct drm_bridge       *next_bridge;
> > +     void __iomem            *regs;
> > +};
> > +
> > +static inline struct imx8mp_hdmi_pvi *
> > +to_imx8mp_hdmi_pvi(struct drm_bridge *bridge)
> > +{
> > +     return container_of(bridge, struct imx8mp_hdmi_pvi, bridge);
> > +}
> > +
> > +static int imx8mp_hdmi_pvi_bridge_attach(struct drm_bridge *bridge,
> > +                                      enum drm_bridge_attach_flags flags)
> > +{
> > +     struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
> > +
> > +     return drm_bridge_attach(bridge->encoder, pvi->next_bridge,
> > +                              bridge, flags);
> > +}
> > +
> > +static void imx8mp_hdmi_pvi_bridge_enable(struct drm_bridge *bridge,
> > +                                       struct drm_bridge_state *bridge_state)
> > +{
> > +     struct drm_atomic_state *state = bridge_state->base.state;
> > +     struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
> > +     struct drm_connector_state *conn_state;
> > +     const struct drm_display_mode *mode;
> > +     struct drm_crtc_state *crtc_state;
> > +     struct drm_connector *connector;
> > +     u32 bus_flags, val;
> > +
> > +     connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
> > +     conn_state = drm_atomic_get_new_connector_state(state, connector);
> > +     crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
> > +
> > +     if (WARN_ON(pm_runtime_resume_and_get(pvi->dev)))
> > +             return;
> > +
> > +     mode = &crtc_state->adjusted_mode;
> > +
> > +     val = FIELD_PREP(PVI_CTRL_MODE_MASK, PVI_CTRL_MODE_LCDIF) | PVI_CTRL_EN;
> > +
> > +     if (mode->flags & DRM_MODE_FLAG_PVSYNC)
> > +             val |= PVI_CTRL_OP_VSYNC_POL | PVI_CTRL_INP_VSYNC_POL;
> > +
> > +     if (mode->flags & DRM_MODE_FLAG_PHSYNC)
> > +             val |= PVI_CTRL_OP_HSYNC_POL | PVI_CTRL_INP_HSYNC_POL;
> > +
> > +     if (pvi->next_bridge->timings)
> > +             bus_flags = pvi->next_bridge->timings->input_bus_flags;
> > +     else if (bridge_state)
> > +             bus_flags = bridge_state->input_bus_cfg.flags;
> > +
> > +     if (bus_flags & DRM_BUS_FLAG_DE_HIGH)
> > +             val |= PVI_CTRL_OP_DE_POL | PVI_CTRL_INP_DE_POL;
> > +
> > +     writel(val, pvi->regs + HTX_PVI_CTRL);
> > +}
> > +
> > +static void imx8mp_hdmi_pvi_bridge_disable(struct drm_bridge *bridge,
> > +                                        struct drm_bridge_state *bridge_state)
> > +{
> > +     struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
> > +
> > +     writel(0x0, pvi->regs + HTX_PVI_CTRL);
> > +
> > +     pm_runtime_put(pvi->dev);
> > +}
> > +
> > +static u32 *
> > +imx8mp_hdmi_pvi_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
> > +                                       struct drm_bridge_state *bridge_state,
> > +                                       struct drm_crtc_state *crtc_state,
> > +                                       struct drm_connector_state *conn_state,
> > +                                       u32 output_fmt,
> > +                                       unsigned int *num_input_fmts)
> > +{
> > +     struct imx8mp_hdmi_pvi *pvi = to_imx8mp_hdmi_pvi(bridge);
> > +     struct drm_bridge *next_bridge = pvi->next_bridge;
> > +     struct drm_bridge_state *next_state;
> > +
> > +     if (!next_bridge->funcs->atomic_get_input_bus_fmts)
> > +             return 0;
> > +
> > +     next_state = drm_atomic_get_new_bridge_state(crtc_state->state,
> > +                                                  next_bridge);
> > +
> > +     return next_bridge->funcs->atomic_get_input_bus_fmts(next_bridge,
> > +                                                          next_state,
> > +                                                          crtc_state,
> > +                                                          conn_state,
> > +                                                          output_fmt,
> > +                                                          num_input_fmts);
> > +}
> > +
> > +static const struct drm_bridge_funcs imx_hdmi_pvi_bridge_funcs = {
> > +     .attach         = imx8mp_hdmi_pvi_bridge_attach,
> > +     .atomic_enable  = imx8mp_hdmi_pvi_bridge_enable,
> > +     .atomic_disable = imx8mp_hdmi_pvi_bridge_disable,
> > +     .atomic_get_input_bus_fmts = imx8mp_hdmi_pvi_bridge_get_input_bus_fmts,
> > +     .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> > +     .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> > +     .atomic_reset = drm_atomic_helper_bridge_reset,
> > +};
> > +
> > +static int imx8mp_hdmi_pvi_probe(struct platform_device *pdev)
> > +{
> > +     struct device_node *remote;
> > +     struct imx8mp_hdmi_pvi *pvi;
> > +
> > +     pvi = devm_kzalloc(&pdev->dev, sizeof(*pvi), GFP_KERNEL);
> > +     if (!pvi)
> > +             return -ENOMEM;
> > +
> > +     platform_set_drvdata(pdev, pvi);
> > +     pvi->dev = &pdev->dev;
> > +
> > +     pvi->regs = devm_platform_ioremap_resource(pdev, 0);
> > +     if (IS_ERR(pvi->regs))
> > +             return PTR_ERR(pvi->regs);
> > +
> > +     /* Get the next bridge in the pipeline. */
> > +     remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
> > +     if (!remote)
> > +             return -EINVAL;
> > +
> > +     pvi->next_bridge = of_drm_find_bridge(remote);
> > +     of_node_put(remote);
> > +
> > +     if (!pvi->next_bridge)
> > +             return dev_err_probe(&pdev->dev, -EPROBE_DEFER,
> > +                                  "could not find next bridge\n");
> > +
> > +     /* Register the bridge. */
> > +     pvi->bridge.funcs = &imx_hdmi_pvi_bridge_funcs;
> > +     pvi->bridge.of_node = pdev->dev.of_node;
> > +     pvi->bridge.timings = pvi->next_bridge->timings;
> > +
> > +     drm_bridge_add(&pvi->bridge);
> > +
> > +     pm_runtime_enable(&pdev->dev);
>
> I would move this just before drm_bridge_add(). In theory, as soon as
> the bridge is added, it could get used, so it's a good practice to
> initialize everything before adding it.
>
> > +
> > +     return 0;
> > +}
> > +
> > +static int imx8mp_hdmi_pvi_remove(struct platform_device *pdev)
> > +{
> > +     struct imx8mp_hdmi_pvi *pvi = platform_get_drvdata(pdev);
> > +
> > +     pm_runtime_disable(&pdev->dev);
> > +
> > +     drm_bridge_remove(&pvi->bridge);
>
> And here you could flip the two as well for consistency.
>
> With these minor changes,
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Lucas,

It's been a few months since there has been any action.  If you want,
I can help apply the suggestions that Laurent has and re-submit with
both of our names if you want.  It would be nice to get this
integrated.

adam
>
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id imx8mp_hdmi_pvi_match[] = {
> > +     {
> > +             .compatible = "fsl,imx8mp-hdmi-pvi",
> > +     }, {
> > +             /* sentinel */
> > +     }
> > +};
> > +MODULE_DEVICE_TABLE(of, imx8mp_hdmi_pvi_match);
> > +
> > +static struct platform_driver imx8mp_hdmi_pvi_driver = {
> > +     .probe  = imx8mp_hdmi_pvi_probe,
> > +     .remove = imx8mp_hdmi_pvi_remove,
> > +     .driver         = {
> > +             .name = "imx-hdmi-pvi",
> > +             .of_match_table = imx8mp_hdmi_pvi_match,
> > +     },
> > +};
> > +module_platform_driver(imx8mp_hdmi_pvi_driver);
> > +
> > +MODULE_DESCRIPTION("i.MX8MP HDMI TX Parallel Video Interface bridge driver");
> > +MODULE_LICENSE("GPL");
>
> --
> Regards,
>
> Laurent Pinchart


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