Re: [PATCH 3/3] drm/bridge: chrontel-ch7033: Add a new driver

From: Laurent Pinchart
Date: Wed Jan 08 2020 - 10:20:54 EST


Hi Lubomir,

Thank you for the patch.

On Fri, Dec 20, 2019 at 08:49:14AM +0100, Lubomir Rintel wrote:
> This is a driver for video encoder with VGA and DVI/HDMI outputs.
>
> There is no documentation for the chip -- the operation was guessed from
> what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
> come from the ch7035 driver in Mediatek's GPL code dump.
>
> Only bare minimum is implemented -- no fancy stuff, such as scaling. That
> would only worsen our misery. We don't load the firmware and we don't need
> to even bother enabling the MCU. There are probably no distributable
> firmware images anyway.
>
> Just like the tda998x driver, this one uses the component framework and
> adds an encoder on component bind, so that it works with the Armada DRM
> driver.

Any chance the Armada DRM driver could use of_drm_find_bridge() to avoid
having to use the component framework everywhere ?

> Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
> with VGA as well as DVI.
>
> Signed-off-by: Lubomir Rintel <lkundrak@xxxxx>
> ---
> drivers/gpu/drm/bridge/Kconfig | 10 +
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/chrontel-ch7033.c | 722 +++++++++++++++++++++++
> 3 files changed, 733 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c
>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 34362976cd6fd..9456ea968c5b7 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -37,6 +37,16 @@ config DRM_CDNS_DSI
> Support Cadence DPI to DSI bridge. This is an internal
> bridge and is meant to be directly embedded in a SoC.
>
> +config DRM_CHRONTEL_CH7033
> + tristate "Chrontel CH7033 Video Encoder"
> + depends on OF
> + select DRM_KMS_HELPER
> + help
> + Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
> + found in the Dell Wyse 3020 thin client.
> +
> + If in doubt, say "N".
> +
> config DRM_DUMB_VGA_DAC
> tristate "Dumb VGA DAC Bridge support"
> depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 4934fcf5a6f82..74a9ab2f17468 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
> obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> +obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
> obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
> obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
> obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
> diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
> new file mode 100644
> index 0000000000000..a3b63984226a4
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
> @@ -0,0 +1,722 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Chrontel CH7033 Video Encoder Driver
> + *
> + * Copyright (C) 2019 Lubomir Rintel
> + */
> +
> +#include <linux/component.h>
> +#include <linux/module.h>
> +#include <linux/gpio/consumer.h>

Could you please sort these alphabetically ?

> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_probe_helper.h>
> +
> +/* Page 0, Register 0x07 */
> +enum {
> + DRI_PD = BIT(3),
> + IO_PD = BIT(5),
> +};
> +
> +/* Page 0, Register 0x08 */
> +enum {
> + DRI_PDDRI = GENMASK(7, 4),
> + PDDAC = GENMASK(3, 1),
> + PANEN = BIT(0),
> +};
> +
> +/* Page 0, Register 0x09 */
> +enum {
> + DPD = BIT(7),
> + GCKOFF = BIT(6),
> + TV_BP = BIT(5),
> + SCLPD = BIT(4),
> + SDPD = BIT(3),
> + VGA_PD = BIT(2),
> + HDBKPD = BIT(1),
> + HDMI_PD = BIT(0),
> +};
> +
> +/* Page 0, Register 0x0a */
> +enum {
> + MEMINIT = BIT(7),
> + MEMIDLE = BIT(6),
> + MEMPD = BIT(5),
> + STOP = BIT(4),
> + LVDS_PD = BIT(3),
> + HD_DVIB = BIT(2),
> + HDCP_PD = BIT(1),
> + MCU_PD = BIT(0),
> +};
> +
> +/* Page 0, Register 0x18 */
> +enum {
> + IDF = GENMASK(7, 4),
> + INTEN = BIT(3),
> + SWAP = GENMASK(2, 0),
> +};
> +
> +enum {
> + BYTE_SWAP_RGB = 0,
> + BYTE_SWAP_RBG = 1,
> + BYTE_SWAP_GRB = 2,
> + BYTE_SWAP_GBR = 3,
> + BYTE_SWAP_BRG = 4,
> + BYTE_SWAP_BGR = 5,
> +};
> +
> +/* Page 0, Register 0x19 */
> +enum {
> + HPO_I = BIT(5),
> + VPO_I = BIT(4),
> + DEPO_I = BIT(3),
> + CRYS_EN = BIT(2),
> + GCLKFREQ = GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x2e */
> +enum {
> + HFLIP = BIT(7),
> + VFLIP = BIT(6),
> + DEPO_O = BIT(5),
> + HPO_O = BIT(4),
> + VPO_O = BIT(3),
> + TE = GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x2b */
> +enum {
> + SWAPS = GENMASK(7, 4),
> + VFMT = GENMASK(3, 0),
> +};
> +
> +/* Page 0, Register 0x54 */
> +enum {
> + COMP_BP = BIT(7),
> + DAC_EN_T = BIT(6),
> + HWO_HDMI_HI = GENMASK(5, 3),
> + HOO_HDMI_HI = GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x57 */
> +enum {
> + FLDSEN = BIT(7),
> + VWO_HDMI_HI = GENMASK(5, 3),
> + VOO_HDMI_HI = GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x7e */
> +enum {
> + HDMI_LVDS_SEL = BIT(7),
> + DE_GEN = BIT(6),
> + PWM_INDEX_HI = BIT(5),
> + USE_DE = BIT(4),
> + R_INT = GENMASK(3, 0),
> +};
> +
> +/* Page 1, Register 0x07 */
> +enum {
> + BPCKSEL = BIT(7),
> + DRI_CMFB_EN = BIT(6),
> + CEC_PUEN = BIT(5),
> + CEC_T = BIT(3),
> + CKINV = BIT(2),
> + CK_TVINV = BIT(1),
> + DRI_CKS2 = BIT(0),
> +};
> +
> +/* Page 1, Register 0x08 */
> +enum {
> + DACG = BIT(6),
> + DACKTST = BIT(5),
> + DEDGEB = BIT(4),
> + SYO = BIT(3),
> + DRI_IT_LVDS = GENMASK(2, 1),
> + DISPON = BIT(0),
> +};
> +
> +/* Page 1, Register 0x0c */
> +enum {
> + DRI_PLL_CP = GENMASK(7, 6),
> + DRI_PLL_DIVSEL = BIT(5),
> + DRI_PLL_N1_1 = BIT(4),
> + DRI_PLL_N1_0 = BIT(3),
> + DRI_PLL_N3_1 = BIT(2),
> + DRI_PLL_N3_0 = BIT(1),
> + DRI_PLL_CKTSTEN = BIT(0),
> +};
> +
> +/* Page 1, Register 0x6b */
> +enum {
> + VCO3CS = GENMASK(7, 6),
> + ICPGBK2_0 = GENMASK(5, 3),
> + DRI_VCO357SC = BIT(2),
> + PDPLL2 = BIT(1),
> + DRI_PD_SER = BIT(0),
> +};
> +
> +/* Page 1, Register 0x6c */
> +enum {
> + PLL2N11 = GENMASK(7, 4),
> + PLL2N5_4 = BIT(3),
> + PLL2N5_TOP = BIT(2),
> + DRI_PLL_PD = BIT(1),
> + PD_I2CM = BIT(0),
> +};
> +
> +/* Page 3, Register 0x28 */
> +enum {
> + DIFF_EN = GENMASK(7, 6),
> + CORREC_EN = GENMASK(5, 4),
> + VGACLK_BP = BIT(3),
> + HM_LV_SEL = BIT(2),
> + HD_VGA_SEL = BIT(1),
> +};
> +
> +/* Page 3, Register 0x2a */
> +enum {
> + LVDSCLK_BP = BIT(7),
> + HDTVCLK_BP = BIT(6),
> + HDMICLK_BP = BIT(5),
> + HDTV_BP = BIT(4),
> + HDMI_BP = BIT(3),
> + THRWL = GENMASK(2, 0),
> +};
> +
> +/* Page 4, Register 0x52 */
> +enum {
> + PGM_ARSTB = BIT(7),
> + MCU_ARSTB = BIT(6),
> + MCU_RETB = BIT(2),
> + RESETIB = BIT(1),
> + RESETDB = BIT(0),
> +};
> +
> +struct ch7033_priv {
> + struct i2c_client *client;
> + struct i2c_adapter *ddc;
> + struct gpio_desc *hpd;
> + struct drm_encoder encoder;
> + struct drm_bridge bridge;
> + struct drm_connector connector;
> +};
> +
> +#define conn_to_ch7033_priv(x) \
> + container_of(x, struct ch7033_priv, connector)
> +#define bridge_to_ch7033_priv(x) \
> + container_of(x, struct ch7033_priv, bridge)
> +
> +
> +static int32_t ch7033_update_reg(struct i2c_client *client,
> + u8 command, u8 value, u8 mask)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_byte_data(client, command);
> + if (ret < 0)
> + return ret;
> +
> + ret &= ~mask;
> + ret |= value;
> + return i2c_smbus_write_byte_data(client, command, ret);

How about using regmap ?

> +}
> +
> +static enum drm_connector_status ch7033_connector_detect(
> + struct drm_connector *connector, bool force)
> +{
> + struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +
> + if (priv->hpd) {
> + if (gpiod_get_value_cansleep(priv->hpd))
> + return connector_status_connected;
> + } else if (priv->ddc) {
> + if (drm_probe_ddc(priv->ddc))
> + return connector_status_connected;
> + }
> +
> + return connector_status_unknown;
> +}
> +
> +static void ch7033_connector_destroy(struct drm_connector *connector)
> +{
> + drm_connector_cleanup(connector);
> +}
> +
> +static const struct drm_connector_funcs ch7033_connector_funcs = {
> + .reset = drm_atomic_helper_connector_reset,
> + .fill_modes = drm_helper_probe_single_connector_modes,
> + .detect = ch7033_connector_detect,
> + .destroy = ch7033_connector_destroy,
> + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int ch7033_connector_get_modes(struct drm_connector *connector)
> +{
> + struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> + struct edid *edid;
> + int ret;
> +
> + edid = drm_get_edid(connector, priv->ddc);
> + drm_connector_update_edid_property(connector, edid);
> + if (edid) {
> + ret = drm_add_edid_modes(connector, edid);
> + kfree(edid);
> + } else {
> + ret = drm_add_modes_noedid(connector, 1920, 1080);
> + drm_set_preferred_mode(connector, 1024, 768);
> + }
> + return ret;
> +}
> +
> +static struct drm_encoder *ch7033_connector_best_encoder(
> + struct drm_connector *connector)
> +{
> + struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +
> + return priv->bridge.encoder;
> +}
> +
> +static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
> + .get_modes = ch7033_connector_get_modes,
> + .best_encoder = ch7033_connector_best_encoder,
> +};
> +
> +static irqreturn_t ch7033_hpd_irq(int irq, void *data)
> +{
> + struct ch7033_priv *priv = data;
> +
> + if (priv->connector.dev)
> + drm_helper_hpd_irq_event(priv->connector.dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int ch7033_bridge_attach(struct drm_bridge *bridge)
> +{
> + struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> + struct drm_connector *connector = &priv->connector;
> + int ret;
> +
> + if (priv->hpd) {
> + connector->polled = DRM_CONNECTOR_POLL_HPD;
> + } else if (priv->ddc) {
> + connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> + DRM_CONNECTOR_POLL_DISCONNECT;
> + }
> +
> + drm_connector_helper_add(connector,
> + &ch7033_connector_helper_funcs);
> + ret = drm_connector_init_with_ddc(bridge->dev, connector,
> + &ch7033_connector_funcs,
> + DRM_MODE_CONNECTOR_DVII,
> + priv->ddc);
> + if (ret) {
> + DRM_ERROR("Failed to initialize connector\n");
> + return ret;
> + }
> +
> + drm_connector_attach_encoder(&priv->connector,
> + priv->bridge.encoder);
> +
> + return 0;
> +}
> +
> +static void ch7033_bridge_detach(struct drm_bridge *bridge)
> +{
> + struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> + drm_connector_cleanup(&priv->connector);
> +}
> +
> +static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
> + const struct drm_display_mode *mode)
> +{
> + if (mode->clock > 165000)
> + return MODE_CLOCK_HIGH;
> + if (mode->hdisplay >= 1920)
> + return MODE_BAD_HVALUE;
> + if (mode->vdisplay >= 1080)
> + return MODE_BAD_VVALUE;
> + return MODE_OK;
> +}
> +
> +static void ch7033_bridge_disable(struct drm_bridge *bridge)
> +{
> + struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x04);
> + ch7033_update_reg(priv->client, 0x52, 0x00, RESETDB);
> +}
> +
> +static void ch7033_bridge_enable(struct drm_bridge *bridge)
> +{
> + struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x04);
> + ch7033_update_reg(priv->client, 0x52, RESETDB, RESETDB);
> +}
> +
> +static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
> + const struct drm_display_mode *mode,
> + const struct drm_display_mode *adjusted_mode)
> +{
> + struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> + int hbporch = mode->hsync_start - mode->hdisplay;
> + int hsynclen = mode->hsync_end - mode->hsync_start;
> + int vbporch = mode->vsync_start - mode->vdisplay;
> + int vsynclen = mode->vsync_end - mode->vsync_start;
> +
> + /*
> + * Page 4
> + */
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x04);
> +
> + /* Turn everything off to set all the registers to their defaults. */
> + i2c_smbus_write_byte_data(priv->client, 0x52, 0x00);
> + /* Bring I/O block up. */
> + i2c_smbus_write_byte_data(priv->client, 0x52, RESETIB);
> +
> + /*
> + * Page 0
> + */
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x00);
> +
> + /* Bring up parts we need from the power down. */
> + ch7033_update_reg(priv->client, 0x07, 0, DRI_PD | IO_PD);
> + ch7033_update_reg(priv->client, 0x08, 0, DRI_PDDRI | PDDAC | PANEN);
> + ch7033_update_reg(priv->client, 0x09, 0, HDMI_PD | VGA_PD |
> + DPD | GCKOFF);
> + ch7033_update_reg(priv->client, 0x0a, 0, HD_DVIB);
> +
> + /* Horizontal input timing. */
> + i2c_smbus_write_byte_data(priv->client, 0x0b, (mode->htotal >> 8) << 3 |
> + (mode->hdisplay >> 8));
> + i2c_smbus_write_byte_data(priv->client, 0x0c, mode->hdisplay);
> + i2c_smbus_write_byte_data(priv->client, 0x0d, mode->htotal);
> + i2c_smbus_write_byte_data(priv->client, 0x0e, (hsynclen >> 8) << 3 |
> + (hbporch >> 8));
> + i2c_smbus_write_byte_data(priv->client, 0x0f, hbporch);
> + i2c_smbus_write_byte_data(priv->client, 0x10, hsynclen);
> +
> + /* Vertical input timing. */
> + i2c_smbus_write_byte_data(priv->client, 0x11, (mode->vtotal >> 8) << 3 |
> + (mode->vdisplay >> 8));
> + i2c_smbus_write_byte_data(priv->client, 0x12, mode->vdisplay);
> + i2c_smbus_write_byte_data(priv->client, 0x13, mode->vtotal);
> + i2c_smbus_write_byte_data(priv->client, 0x14, ((vsynclen >> 8) << 3) |
> + (vbporch >> 8));
> + i2c_smbus_write_byte_data(priv->client, 0x15, vbporch);
> + i2c_smbus_write_byte_data(priv->client, 0x16, vsynclen);
> +
> + /* Input color swap. */
> + ch7033_update_reg(priv->client, 0x18, BYTE_SWAP_BGR, SWAP);
> +
> + /* Input clock and sync polarity. */
> + ch7033_update_reg(priv->client, 0x19, mode->clock >> 16, 0x1);
> + ch7033_update_reg(priv->client, 0x19,
> + (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
> + (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
> + mode->clock >> 16,
> + HPO_I | VPO_I | GCLKFREQ);
> + i2c_smbus_write_byte_data(priv->client, 0x1a, mode->clock >> 8);
> + i2c_smbus_write_byte_data(priv->client, 0x1b, mode->clock);
> +
> + /* Horizontal output timing. */
> + i2c_smbus_write_byte_data(priv->client, 0x1f, (mode->htotal >> 8) << 3 |
> + (mode->hdisplay >> 8));
> + i2c_smbus_write_byte_data(priv->client, 0x20, mode->hdisplay);
> + i2c_smbus_write_byte_data(priv->client, 0x21, mode->htotal);
> +
> + /* Vertical output timing. */
> + i2c_smbus_write_byte_data(priv->client, 0x25, (mode->vtotal >> 8) << 3 |
> + (mode->vdisplay >> 8));
> + i2c_smbus_write_byte_data(priv->client, 0x26, mode->vdisplay);
> + i2c_smbus_write_byte_data(priv->client, 0x27, mode->vtotal);
> +
> + /* VGA channel bypass */
> + ch7033_update_reg(priv->client, 0x2b, 9, VFMT);
> +
> + /* Output sync polarity. */
> + ch7033_update_reg(priv->client, 0x2e,
> + (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
> + (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0,
> + HPO_O | VPO_O);
> +
> + /* HDMI horizontal output timing. */
> + ch7033_update_reg(priv->client, 0x54, (hsynclen >> 8) << 3 |
> + (hbporch >> 8),
> + HWO_HDMI_HI | HOO_HDMI_HI);
> + i2c_smbus_write_byte_data(priv->client, 0x55, hbporch);
> + i2c_smbus_write_byte_data(priv->client, 0x56, hsynclen);
> +
> + /* HDMI vertical output timing. */
> + ch7033_update_reg(priv->client, 0x57, (vsynclen >> 8) << 3 |
> + (vbporch >> 8),
> + VWO_HDMI_HI | VOO_HDMI_HI);
> + i2c_smbus_write_byte_data(priv->client, 0x58, vbporch);
> + i2c_smbus_write_byte_data(priv->client, 0x59, vsynclen);
> +
> + /* Pick HDMI, not LVDS. */
> + ch7033_update_reg(priv->client, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
> +
> + /*
> + * Page 1
> + */
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x01);
> +
> + /* No idea what these do, but VGA is wobbly and blinky without them. */
> + ch7033_update_reg(priv->client, 0x07, CKINV, CKINV);
> + ch7033_update_reg(priv->client, 0x08, DISPON, DISPON);
> +
> + /* DRI PLL */
> + ch7033_update_reg(priv->client, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
> + if (mode->clock <= 40000) {
> + ch7033_update_reg(priv->client, 0x0c, 0,
> + DRI_PLL_N1_1 |
> + DRI_PLL_N1_0 |
> + DRI_PLL_N3_1 |
> + DRI_PLL_N3_0);
> + } else if (mode->clock < 80000) {
> + ch7033_update_reg(priv->client, 0x0c, DRI_PLL_N3_0 |
> + DRI_PLL_N1_0,
> + DRI_PLL_N1_1 |
> + DRI_PLL_N1_0 |
> + DRI_PLL_N3_1 |
> + DRI_PLL_N3_0);
> + } else {
> + ch7033_update_reg(priv->client, 0x0c, DRI_PLL_N3_1 |
> + DRI_PLL_N1_1,
> + DRI_PLL_N1_1 |
> + DRI_PLL_N1_0 |
> + DRI_PLL_N3_1 |
> + DRI_PLL_N3_0);
> + }
> +
> + /* This seems to be color calibration for VGA. */
> + i2c_smbus_write_byte_data(priv->client, 0x64, 0x29); /* LSB Blue */
> + i2c_smbus_write_byte_data(priv->client, 0x65, 0x29); /* LSB Green */
> + i2c_smbus_write_byte_data(priv->client, 0x66, 0x29); /* LSB Red */
> + i2c_smbus_write_byte_data(priv->client, 0x67, 0x00); /* MSB Blue */
> + i2c_smbus_write_byte_data(priv->client, 0x68, 0x00); /* MSB Green */
> + i2c_smbus_write_byte_data(priv->client, 0x69, 0x00); /* MSB Red */
> +
> + ch7033_update_reg(priv->client, 0x6b, 0x00, DRI_PD_SER);
> + ch7033_update_reg(priv->client, 0x6c, 0x00, DRI_PLL_PD);
> +
> + /*
> + * Page 3
> + */
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x03);
> +
> + /* More bypasses and apparently another HDMI/LVDS selector. */
> + ch7033_update_reg(priv->client, 0x28, VGACLK_BP | HM_LV_SEL,
> + VGACLK_BP | HM_LV_SEL);
> + ch7033_update_reg(priv->client, 0x2a, HDMICLK_BP | HDMI_BP,
> + HDMICLK_BP | HDMI_BP);
> +
> + /*
> + * Page 4
> + */
> + i2c_smbus_write_byte_data(priv->client, 0x03, 0x04);
> +
> + /* Output clock. */
> + i2c_smbus_write_byte_data(priv->client, 0x10, mode->clock >> 16);
> + i2c_smbus_write_byte_data(priv->client, 0x11, mode->clock >> 8);
> + i2c_smbus_write_byte_data(priv->client, 0x12, mode->clock);
> +}
> +
> +static const struct drm_bridge_funcs ch7033_bridge_funcs = {
> + .attach = ch7033_bridge_attach,
> + .detach = ch7033_bridge_detach,
> + .mode_valid = ch7033_bridge_mode_valid,
> + .disable = ch7033_bridge_disable,
> + .enable = ch7033_bridge_enable,
> + .mode_set = ch7033_bridge_mode_set,
> +};
> +
> +static void ch7033_encoder_destroy(struct drm_encoder *encoder)
> +{
> + drm_encoder_cleanup(encoder);
> +}
> +
> +static const struct drm_encoder_funcs ch7033_encoder_funcs = {
> + .destroy = ch7033_encoder_destroy,
> +};
> +
> +static int ch7033_bind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct drm_device *drm = data;
> + struct ch7033_priv *priv = dev_get_drvdata(dev);
> + uint32_t crtcs;
> + int ret;
> +
> + crtcs = drm_of_find_possible_crtcs(drm, dev->of_node);
> + priv->encoder.possible_crtcs = crtcs;
> +
> + ret = drm_encoder_init(drm, &priv->encoder, &ch7033_encoder_funcs,
> + DRM_MODE_ENCODER_TMDS, NULL);

Bridge drivers must not create encoders, this is the responsibility of
the display controller driver.

> + if (ret)
> + return ret;
> +
> + ret = drm_bridge_attach(&priv->encoder, &priv->bridge, NULL);
> + if (ret)
> + drm_encoder_cleanup(&priv->encoder);
> +
> + return ret;
> +}
> +
> +static void ch7033_unbind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct ch7033_priv *priv = dev_get_drvdata(dev);
> +
> + drm_encoder_cleanup(&priv->encoder);
> +}
> +
> +static const struct component_ops ch7033_ops = {
> + .bind = ch7033_bind,
> + .unbind = ch7033_unbind,
> +};
> +
> +static int ch7033_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device_node *ddc_node, *conn_node;
> + struct device *dev = &client->dev;
> + struct ch7033_priv *priv;
> + struct i2c_adapter *ddc;
> + int ret;
> +
> + conn_node = of_graph_get_remote_node(dev->of_node, 1, -1);
> + if (!conn_node) {
> + dev_err(&client->dev, "unable to get the connector node\n");
> + return -EINVAL;
> + }
> +
> + ddc_node = of_parse_phandle(conn_node, "ddc-i2c-bus", 0);
> + if (ddc_node) {
> + ddc = of_get_i2c_adapter_by_node(ddc_node);
> + if (!ddc) {
> + ret = -EPROBE_DEFER;
> + goto out;
> + }
> + } else {
> + dev_info(&client->dev, "no DDC bus for connector\n");
> + ddc = NULL;
> + }
> +
> + ret = i2c_smbus_read_byte_data(client, 0x00);

Any idea what this is for ?

> + if ((i2c_smbus_read_byte_data(client, 0x00) & 0xf7) != 0x56) {
> + dev_err(&client->dev, "the device is not a ch7033\n");
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + i2c_smbus_write_byte_data(client, 0x03, 0x04);
> + ret = i2c_smbus_read_byte_data(client, 0x51) & 0x0f;
> + if (ret != 3) {
> + dev_err(&client->dev, "unknown revision %d\n", ret);
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + dev_set_drvdata(dev, priv);
> +
> + INIT_LIST_HEAD(&priv->bridge.list);
> +
> + priv->client = client;
> + priv->ddc = ddc;
> +
> + priv->hpd = devm_gpiod_get_from_of_node(dev, conn_node, "hpd-gpios",
> + 0, GPIOD_IN, "HPD");
> + if (IS_ERR(priv->hpd)) {
> + if (PTR_ERR(priv->hpd) == -ENOENT) {
> + dev_info(&client->dev, "no HPD pin\n");
> + priv->hpd = NULL;
> + } else {
> + ret = PTR_ERR(priv->hpd);
> + goto out;
> + }
> + }
> +
> + if (priv->hpd) {
> + ret = devm_request_threaded_irq(&client->dev,
> + gpiod_to_irq(priv->hpd),
> + NULL, ch7033_hpd_irq,
> + IRQF_TRIGGER_RISING |
> + IRQF_TRIGGER_FALLING |
> + IRQF_ONESHOT,
> + "HPD", priv);
> + if (ret) {
> + dev_err(&client->dev, "failed to request irq\n");
> + goto out;
> + }
> + }

Instead of manually handling the connector DT node, how about using
https://patchwork.freedesktop.org/patch/346013/ ? We're about to merge
it.

> +
> + priv->bridge.funcs = &ch7033_bridge_funcs;
> + priv->bridge.of_node = dev->of_node;
> +
> + drm_bridge_add(&priv->bridge);
> +
> + ret = component_add(dev, &ch7033_ops);
> + if (ret) {
> + drm_bridge_remove(&priv->bridge);
> + goto out;
> + }
> +
> + dev_info(dev, "Chrontel CH7033 Video Encoder\n");
> +out:
> + of_node_put(conn_node);
> + return ret;
> +}
> +
> +static int ch7033_remove(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct ch7033_priv *priv = dev_get_drvdata(dev);
> +
> + component_del(dev, &ch7033_ops);
> + drm_bridge_remove(&priv->bridge);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id ch7033_dt_ids[] = {
> + { .compatible = "chrontel,ch7033", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
> +
> +static const struct i2c_device_id ch7033_ids[] = {
> + { "ch7033", 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, ch7033_ids);
> +
> +static struct i2c_driver ch7033_driver = {
> + .probe = ch7033_probe,
> + .remove = ch7033_remove,
> + .driver = {
> + .name = "ch7033",
> + .of_match_table = of_match_ptr(ch7033_dt_ids),
> + },
> + .id_table = ch7033_ids,
> +};
> +
> +module_i2c_driver(ch7033_driver);
> +
> +MODULE_AUTHOR("Lubomir Rintel <lkundrak@xxxxx>");
> +MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
> +MODULE_LICENSE("GPL v2");

--
Regards,

Laurent Pinchart