[EXT] Re: [PATCH v12 4/7] drm: bridge: Cadence: Add MHDP8501 DP/HDMI driver

Sandor Yu sandor.yu at nxp.com
Sun Feb 4 06:29:05 PST 2024


Hi Alexander,

Thanks your comments,

>
>
> Hi Sandor,
>
> thanks for the update.
>
> Am Mittwoch, 10. Januar 2024, 02:08:45 CET schrieb Sandor Yu:
> > Add a new DRM DisplayPort and HDMI bridge driver for Candence
> MHDP8501
> > used in i.MX8MQ SOC. MHDP8501 could support HDMI or DisplayPort
> > standards according embedded Firmware running in the uCPU.
> >
> > For iMX8MQ SOC, the DisplayPort/HDMI FW was loaded and activated by
> > SOC's ROM code. Bootload binary included respective specific firmware
> > is required.
> >
> > Driver will check display connector type and then load the
> > corresponding driver.
> >
> > Signed-off-by: Sandor Yu <Sandor.yu at nxp.com>
> > Tested-by: Alexander Stein <alexander.stein at ew.tq-group.com>
> > ---
> > v11->v12:
> > - Replace DRM_INFO with dev_info or dev_warn.
> > - Replace DRM_ERROR with dev_err.
> > - Return ret when cdns_mhdp_dpcd_read failed in function
> > cdns_dp_aux_transferi(). - Remove unused parmeter in function
> > cdns_dp_get_msa_misc
> >   and use two separate variables for color space and bpc.
> > - Add year 2024 to copyright.
> >
> >  drivers/gpu/drm/bridge/cadence/Kconfig        |  16 +
> >  drivers/gpu/drm/bridge/cadence/Makefile       |   2 +
> >  .../drm/bridge/cadence/cdns-mhdp8501-core.c   | 315 ++++++++
> >  .../drm/bridge/cadence/cdns-mhdp8501-core.h   | 365 +++++++++
> >  .../gpu/drm/bridge/cadence/cdns-mhdp8501-dp.c | 699
> ++++++++++++++++++
> >  .../drm/bridge/cadence/cdns-mhdp8501-hdmi.c   | 678
> +++++++++++++++++
> >  6 files changed, 2075 insertions(+)
> >  create mode 100644
> > drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-core.c
> >  create mode 100644
> > drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-core.h
> >  create mode 100644
> drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-dp.c
> >  create mode 100644
> > drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-hdmi.c
> >
> > diff --git a/drivers/gpu/drm/bridge/cadence/Kconfig
> > b/drivers/gpu/drm/bridge/cadence/Kconfig index
> > e0973339e9e33..45848e741f5f4
> > 100644
> > --- a/drivers/gpu/drm/bridge/cadence/Kconfig
> > +++ b/drivers/gpu/drm/bridge/cadence/Kconfig
> > @@ -51,3 +51,19 @@ config DRM_CDNS_MHDP8546_J721E
> >         initializes the J721E Display Port and sets up the
> >         clock and data muxes.
> >  endif
> > +
> > +config DRM_CDNS_MHDP8501
> > +     tristate "Cadence MHDP8501 DP/HDMI bridge"
> > +     select DRM_KMS_HELPER
> > +     select DRM_PANEL_BRIDGE
> > +     select DRM_DISPLAY_DP_HELPER
> > +     select DRM_DISPLAY_HELPER
> > +     select CDNS_MHDP_HELPER
> > +     select DRM_CDNS_AUDIO
> > +     depends on OF
> > +     help
> > +       Support Cadence MHDP8501 DisplayPort/HDMI bridge.
> > +       Cadence MHDP8501 support one or more protocols,
> > +       including DisplayPort and HDMI.
> > +       To use the DP and HDMI drivers, their respective
> > +       specific firmware is required.
> > diff --git a/drivers/gpu/drm/bridge/cadence/Makefile
> > b/drivers/gpu/drm/bridge/cadence/Makefile index
> > 087dc074820d7..02c1a9f3cf6fc 100644
> > --- a/drivers/gpu/drm/bridge/cadence/Makefile
> > +++ b/drivers/gpu/drm/bridge/cadence/Makefile
> > @@ -6,3 +6,5 @@ obj-$(CONFIG_CDNS_MHDP_HELPER) +=
> cdns-mhdp-helper.o
> >  obj-$(CONFIG_DRM_CDNS_MHDP8546) += cdns-mhdp8546.o
> cdns-mhdp8546-y
> > := cdns-mhdp8546-core.o cdns-mhdp8546-hdcp.o
> >  cdns-mhdp8546-$(CONFIG_DRM_CDNS_MHDP8546_J721E) +=
> > cdns-mhdp8546-j721e.o
> > +obj-$(CONFIG_DRM_CDNS_MHDP8501) += cdns-mhdp8501.o
> cdns-mhdp8501-y :=
> > +cdns-mhdp8501-core.o cdns-mhdp8501-dp.o
> > cdns-mhdp8501-hdmi.o diff --git
> > a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-core.c
> > b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-core.c new file mode
> > 100644 index 0000000000000..3080c7507a012
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-core.c
> > @@ -0,0 +1,315 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Cadence Display Port Interface (DP) driver
> > + *
> > + * Copyright (C) 2023, 2024 NXP Semiconductor, Inc.
> > + *
> > + */
> > +#include <drm/drm_of.h>
> > +#include <drm/drm_print.h>
> > +#include <linux/clk.h>
> > +#include <linux/irq.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of_device.h>
>
> Since commit d57d584ef69de ("of: Stop circularly including of_device.h and
> of_platform.h") you to explicitly include linux/platform_device.h here. Please
> compile against next tree.

OK, I will check it on next tree.

>
> > +#include <linux/phy/phy.h>
> > +
> > +#include "cdns-mhdp8501-core.h"
> > +
> > [snip]
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-dp.c
> > b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-dp.c new file mode
> > 100644 index 0000000000000..6963c7143a3b0
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-dp.c
> > @@ -0,0 +1,699 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Cadence MHDP8501 DisplayPort(DP) bridge driver
> > + *
> > + * Copyright (C) 2019-2024 NXP Semiconductor, Inc.
> > + *
> > + */
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_edid.h>
> > +#include <drm/drm_print.h>
> > +#include <linux/phy/phy.h>
> > +#include <linux/phy/phy-dp.h>
> > +
> > +#include "cdns-mhdp8501-core.h"
> > +
> > +#define LINK_TRAINING_TIMEOUT_MS     500
> > +#define LINK_TRAINING_RETRY_MS               20
> > +
> > +ssize_t cdns_dp_aux_transfer(struct drm_dp_aux *aux,
> > +                          struct drm_dp_aux_msg *msg) {
> > +     struct cdns_mhdp8501_device *mhdp = dev_get_drvdata(aux->dev);
> > +     bool native = msg->request & (DP_AUX_NATIVE_WRITE &
> DP_AUX_NATIVE_READ);
> > +     int ret;
> > +
> > +     /* Ignore address only message */
> > +     if (!msg->size || !msg->buffer) {
> > +             msg->reply = native ?
> > +                     DP_AUX_NATIVE_REPLY_ACK :
> DP_AUX_I2C_REPLY_ACK;
> > +             return msg->size;
> > +     }
> > +
> > +     if (!native) {
> > +             dev_err(mhdp->dev, "%s: only native messages
> > + supported\n",
> __func__);
> > +             return -EINVAL;
> > +     }
> > +
> > +     /* msg sanity check */
> > +     if (msg->size > DP_AUX_MAX_PAYLOAD_BYTES) {
> > +             dev_err(mhdp->dev, "%s: invalid msg: size(%zu),
> request(%x)\n",
> > +                     __func__, msg->size, (unsigned int)msg-
> >request);
> > +             return -EINVAL;
> > +     }
> > +
> > +     if (msg->request == DP_AUX_NATIVE_WRITE) {
> > +             const u8 *buf = msg->buffer;
> > +             int i;
> > +
> > +             for (i = 0; i < msg->size; ++i) {
> > +                     ret = cdns_mhdp_dpcd_write(&mhdp->base,
> > +                                                msg->address +
> i, buf[i]);
> > +                     if (ret < 0) {
> > +                             dev_err(mhdp->dev, "Failed to write
> DPCD\n");
> > +                             return ret;
> > +                     }
> > +             }
> > +             msg->reply = DP_AUX_NATIVE_REPLY_ACK;
> > +             return msg->size;
> > +     }
> > +
> > +     if (msg->request == DP_AUX_NATIVE_READ) {
> > +             ret = cdns_mhdp_dpcd_read(&mhdp->base, msg->address,
> > +                                       msg->buffer, msg->size);
> > +             if (ret < 0)
> > +                     return ret;
> > +             msg->reply = DP_AUX_NATIVE_REPLY_ACK;
> > +             return msg->size;
> > +     }
> > +     return 0;
> > +}
> > +
> > +int cdns_dp_aux_destroy(struct cdns_mhdp8501_device *mhdp) {
> > +     drm_dp_aux_unregister(&mhdp->dp.aux);
> > +
> > +     return 0;
> > +}
> > +
> > +static int cdns_dp_get_msa_misc(struct video_info *video) {
> > +     u32 msa_misc;
> > +     u8 color_space = 0;
> > +     u8 bpc = 0;
> > +
> > +     switch (video->color_fmt) {
> > +     /* set YUV default color space conversion to BT601 */
> > +     case DRM_COLOR_FORMAT_YCBCR444:
> > +             color_space = 6 + BT_601 * 8;
> > +             break;
> > +     case DRM_COLOR_FORMAT_YCBCR422:
> > +             color_space = 5 + BT_601 * 8;
> > +             break;
> > +     case DRM_COLOR_FORMAT_YCBCR420:
> > +             color_space = 5;
> > +             break;
> > +     case DRM_COLOR_FORMAT_RGB444:
> > +     default:
> > +             color_space = 0;
> > +             break;
> > +     };
> > +
> > +     switch (video->bpc) {
> > +     case 6:
> > +             bpc = 0;
> > +             break;
> > +     case 10:
> > +             bpc = 2;
> > +             break;
> > +     case 12:
> > +             bpc = 3;
> > +             break;
> > +     case 16:
> > +             bpc = 4;
> > +             break;
> > +     case 8:
> > +     default:
> > +             bpc = 1;
> > +             break;
> > +     };
> > +
> > +     msa_misc = (color_space << 1) | (bpc << 5);
>
> This looks much nicer, thanks. But please order them in descending shift
> width: bpc first then color_space.
>

OK.

> > +
> > +     return msa_misc;
> > +}
> > +
> > [snip]
> > +int cdns_dp_set_host_cap(struct cdns_mhdp8501_device *mhdp)
>
> This can be made static.

OK.

>
> > +{
> > +     u8 msg[8];
> > +     int ret;
> > +
> > +     msg[0] = drm_dp_link_rate_to_bw_code(mhdp->dp.rate);
> > +     msg[1] = mhdp->dp.num_lanes | SCRAMBLER_EN;
> > +     msg[2] = VOLTAGE_LEVEL_2;
> > +     msg[3] = PRE_EMPHASIS_LEVEL_3;
> > +     msg[4] = PTS1 | PTS2 | PTS3 | PTS4;
> > +     msg[5] = FAST_LT_NOT_SUPPORT;
> > +     msg[6] = mhdp->lane_mapping;
> > +     msg[7] = ENHANCED;
> > +
> > +     mutex_lock(&mhdp->mbox_mutex);
> > +
> > +     ret = cdns_mhdp_mailbox_send(&mhdp->base,
> MB_MODULE_ID_DP_TX,
> > +                                  DPTX_SET_HOST_CAPABILITIES,
> > +                                  sizeof(msg), msg);
> > +
> > +     mutex_unlock(&mhdp->mbox_mutex);
> > +
> > +     if (ret)
> > +             dev_err(mhdp->dev, "set host cap failed: %d\n", ret);
> > +
> > +     return ret;
> > +}
> > [snip]
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-hdmi.c
> > b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-hdmi.c new file mode
> > 100644 index 0000000000000..ae21f7dfe5e94
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8501-hdmi.c
> > @@ -0,0 +1,678 @@
> > [snip]
> > +bool cdns_hdmi_bridge_mode_fixup(struct drm_bridge *bridge,
> > +                              const struct drm_display_mode
> *mode,
> > +                              struct drm_display_mode
> *adjusted_mode)
>
> This can be made static.

OK, thanks!

Sandor

>
> Thanks and best regards,
> Alexander
>
> > +{
> > +     struct cdns_mhdp8501_device *mhdp = bridge->driver_private;
> > +     struct video_info *video = &mhdp->video_info;
> > +
> > +     /* The only currently supported format */
> > +     video->bpc = 8;
> > +     video->color_fmt = DRM_COLOR_FORMAT_RGB444;
> > +
> > +     return true;
> > +}
> > +
> > +static enum drm_connector_status
> > +cdns_hdmi_bridge_detect(struct drm_bridge *bridge) {
> > +     struct cdns_mhdp8501_device *mhdp = bridge->driver_private;
> > +
> > +     return cdns_mhdp8501_detect(mhdp); }
> > +
> > +static struct edid *cdns_hdmi_bridge_get_edid(struct drm_bridge *bridge,
> > +                                           struct drm_connector
> *connector)
> > +{
> > +     struct cdns_mhdp8501_device *mhdp = bridge->driver_private;
> > +
> > +     return drm_do_get_edid(connector, cdns_hdmi_get_edid_block,
> > +mhdp); }
> > +
> > +static void cdns_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
> > +                                         struct drm_bridge_state
> *old_state)
> > +{
> > +     struct cdns_mhdp8501_device *mhdp = bridge->driver_private;
> > +
> > +     mhdp->curr_conn = NULL;
> > +
> > +     /* Mailbox protect for HDMI PHY access */
> > +     mutex_lock(&mhdp->mbox_mutex);
> > +     phy_power_off(mhdp->phy);
> > +     mutex_unlock(&mhdp->mbox_mutex); }
> > +
> > +static void cdns_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
> > +                                        struct drm_bridge_state
> *old_state)
> > +{
> > +     struct cdns_mhdp8501_device *mhdp = bridge->driver_private;
> > +     struct drm_atomic_state *state = old_state->base.state;
> > +     struct drm_connector *connector;
> > +     struct drm_crtc_state *crtc_state;
> > +     struct drm_connector_state *conn_state;
> > +     const struct drm_display_mode *mode;
> > +
> > +     connector = drm_atomic_get_new_connector_for_encoder(state,
> > +
> bridge->encoder);
> > +     if (WARN_ON(!connector))
> > +             return;
> > +
> > +     mhdp->curr_conn = connector;
> > +
> > +     conn_state = drm_atomic_get_new_connector_state(state,
> connector);
> > +     if (WARN_ON(!conn_state))
> > +             return;
> > +
> > +     crtc_state = drm_atomic_get_new_crtc_state(state,
> conn_state->crtc);
> > +     if (WARN_ON(!crtc_state))
> > +             return;
> > +
> > +     mode = &crtc_state->adjusted_mode;
> > +     dev_dbg(mhdp->dev, "Mode: %dx%dp%d\n",
> > +             mode->hdisplay, mode->vdisplay, mode->clock);
> > +     memcpy(&mhdp->mode, mode, sizeof(struct drm_display_mode));
> > +
> > +     cdns_hdmi_mode_set(mhdp);
> > +}
> > +
> > +const struct drm_bridge_funcs cdns_hdmi_bridge_funcs = {
> > +     .attach = cdns_hdmi_bridge_attach,
> > +     .detect = cdns_hdmi_bridge_detect,
> > +     .get_edid = cdns_hdmi_bridge_get_edid,
> > +     .mode_valid = cdns_hdmi_bridge_mode_valid,
> > +     .mode_fixup = cdns_hdmi_bridge_mode_fixup,
> > +     .atomic_enable = cdns_hdmi_bridge_atomic_enable,
> > +     .atomic_disable = cdns_hdmi_bridge_atomic_disable,
> > +     .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, };
>
>
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