[PATCH 2/2] drm/bridge: lt9211: Add Lontium LT9211 bridge driver
Robert Foss
robert.foss at linaro.org
Tue Apr 19 13:48:39 UTC 2022
On Wed, 30 Mar 2022 at 23:23, Marek Vasut <marex at denx.de> wrote:
>
> Add driver for Lontium LT9211 Single/Dual-Link DSI/LVDS or Single DPI to
> Single-link/Dual-Link DSI/LVDS or Single DPI bridge. This chip is highly
> capable at converting formats, but sadly it is also highly undocumented.
>
> This driver is written without any documentation from Lontium and based
> only on shreds of information available in various obscure example codes,
> hence long runs of unknown register patches and lengthy delays in various
> places. Whichever register meaning could be divined from its behavior has
> at least a comment around it.
>
> Currently the only mode tested is Single-link DSI to Single-link LVDS.
> Dual-link LVDS might work as well, the register programming is in place,
> but is untested.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Cc: Maxime Ripard <maxime at cerno.tech>
> Cc: Robert Foss <robert.foss at linaro.org>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> To: dri-devel at lists.freedesktop.org
> ---
> drivers/gpu/drm/bridge/Kconfig | 13 +
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/lontium-lt9211.c | 802 ++++++++++++++++++++++++
> 3 files changed, 816 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/lontium-lt9211.c
>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 044a268d7c89..dd9f0b32a5a9 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -98,6 +98,19 @@ config DRM_LONTIUM_LT8912B
> Say M here if you want to support this hardware as a module.
> The module will be named "lontium-lt8912b".
>
> +config DRM_LONTIUM_LT9211
> + tristate "Lontium LT9211 DSI/LVDS/DPI bridge"
> + depends on OF
> + select DRM_PANEL_BRIDGE
> + select DRM_KMS_HELPER
> + select DRM_MIPI_DSI
> + select REGMAP_I2C
> + help
> + Driver for Lontium LT9211 Single/Dual-Link DSI/LVDS or Single DPI
> + input to Single-link/Dual-Link DSI/LVDS or Single DPI output bridge
> + chip.
> + Please say Y if you have such hardware.
> +
> config DRM_LONTIUM_LT9611
> tristate "Lontium LT9611 DSI/HDMI bridge"
> select SND_SOC_HDMI_CODEC if SND_SOC
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 0774e289f81b..f800b2331d9e 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -6,6 +6,7 @@ obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o
> obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
> obj-$(CONFIG_DRM_ITE_IT6505) += ite-it6505.o
> obj-$(CONFIG_DRM_LONTIUM_LT8912B) += lontium-lt8912b.o
> +obj-$(CONFIG_DRM_LONTIUM_LT9211) += lontium-lt9211.o
> obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o
> obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o
> obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9211.c b/drivers/gpu/drm/bridge/lontium-lt9211.c
> new file mode 100644
> index 000000000000..e92821fbc639
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/lontium-lt9211.c
> @@ -0,0 +1,802 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Lontium LT9211 bridge driver
> + *
> + * LT9211 is capable of converting:
> + * 2xDSI/2xLVDS/1xDPI -> 2xDSI/2xLVDS/1xDPI
> + * Currently supported is:
> + * 1xDSI -> 1xLVDS
> + *
> + * Copyright (C) 2022 Marek Vasut <marex at denx.de>
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.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>
> +
> +#define REG_PAGE_CONTROL 0xff
> +#define REG_CHIPID0 0x8100
> +#define REG_CHIPID0_VALUE 0x18
> +#define REG_CHIPID1 0x8101
> +#define REG_CHIPID1_VALUE 0x01
> +#define REG_CHIPID2 0x8102
> +#define REG_CHIPID2_VALUE 0xe3
> +
> +#define REG_DSI_LANE 0xd000
> +/* DSI lane count - 0 means 4 lanes ; 1, 2, 3 means 1, 2, 3 lanes. */
> +#define REG_DSI_LANE_COUNT(n) ((n) & 3)
> +
> +struct lt9211 {
> + struct drm_bridge bridge;
> + struct device *dev;
> + struct regmap *regmap;
> + struct mipi_dsi_device *dsi;
> + struct drm_bridge *panel_bridge;
> + struct gpio_desc *reset_gpio;
> + struct regulator *vccio;
> + bool lvds_dual_link;
> + bool lvds_dual_link_even_odd_swap;
> +};
> +
> +static const struct regmap_range lt9211_rw_ranges[] = {
> + regmap_reg_range(0xff, 0xff),
> + regmap_reg_range(0x8100, 0x816b),
> + regmap_reg_range(0x8200, 0x82aa),
> + regmap_reg_range(0x8500, 0x85ff),
> + regmap_reg_range(0x8600, 0x86a0),
> + regmap_reg_range(0x8700, 0x8746),
> + regmap_reg_range(0xd000, 0xd0a7),
> + regmap_reg_range(0xd400, 0xd42c),
> + regmap_reg_range(0xd800, 0xd838),
> + regmap_reg_range(0xd9c0, 0xd9d5),
> +};
> +
> +static const struct regmap_access_table lt9211_rw_table = {
> + .yes_ranges = lt9211_rw_ranges,
> + .n_yes_ranges = ARRAY_SIZE(lt9211_rw_ranges),
> +};
> +
> +static const struct regmap_range_cfg lt9211_range = {
> + .name = "lt9211",
> + .range_min = 0x0000,
> + .range_max = 0xda00,
> + .selector_reg = REG_PAGE_CONTROL,
> + .selector_mask = 0xff,
> + .selector_shift = 0,
> + .window_start = 0,
> + .window_len = 0x100,
> +};
> +
> +static const struct regmap_config lt9211_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .rd_table = <9211_rw_table,
> + .wr_table = <9211_rw_table,
> + .volatile_table = <9211_rw_table,
> + .ranges = <9211_range,
> + .num_ranges = 1,
> + .cache_type = REGCACHE_RBTREE,
> + .max_register = 0xda00,
> +};
> +
> +static struct lt9211 *bridge_to_lt9211(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct lt9211, bridge);
> +}
> +
> +static int lt9211_attach(struct drm_bridge *bridge,
> + enum drm_bridge_attach_flags flags)
> +{
> + struct lt9211 *ctx = bridge_to_lt9211(bridge);
> +
> + return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
> + &ctx->bridge, flags);
> +}
> +
> +static int lt9211_read_chipid(struct lt9211 *ctx)
> +{
> + u8 chipid[3];
> + int ret;
> +
> + /* Read Chip ID registers and verify the chip can communicate. */
> + ret = regmap_bulk_read(ctx->regmap, REG_CHIPID0, chipid, 3);
> + if (ret < 0) {
> + dev_err(ctx->dev, "Failed to read Chip ID: %d\n", ret);
> + return ret;
> + }
> +
> + /* Test for known Chip ID. */
> + if (chipid[0] != REG_CHIPID0_VALUE || chipid[1] != REG_CHIPID1_VALUE ||
> + chipid[2] != REG_CHIPID2_VALUE) {
> + dev_err(ctx->dev, "Unknown Chip ID: 0x%02x 0x%02x 0x%02x\n",
> + chipid[0], chipid[1], chipid[2]);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int lt9211_system_init(struct lt9211 *ctx)
> +{
> + const struct reg_sequence lt9211_system_init_seq[] = {
> + { 0x8201, 0x18 },
> + { 0x8606, 0x61 },
> + { 0x8607, 0xa8 },
> + { 0x8714, 0x08 },
> + { 0x8715, 0x00 },
> + { 0x8718, 0x0f },
> + { 0x8722, 0x08 },
> + { 0x8723, 0x00 },
> + { 0x8726, 0x0f },
> + { 0x810b, 0xfe },
> + };
> +
> + return regmap_multi_reg_write(ctx->regmap, lt9211_system_init_seq,
> + ARRAY_SIZE(lt9211_system_init_seq));
> +}
> +
> +static int lt9211_configure_rx(struct lt9211 *ctx)
> +{
> + const struct reg_sequence lt9211_rx_phy_seq[] = {
> + { 0x8202, 0x44 },
> + { 0x8204, 0xa0 },
> + { 0x8205, 0x22 },
> + { 0x8207, 0x9f },
> + { 0x8208, 0xfc },
> + /* ORR with 0xf8 here to enable DSI DN/DP swap. */
> + { 0x8209, 0x01 },
> + { 0x8217, 0x0c },
> + { 0x8633, 0x1b },
> + };
> +
> + const struct reg_sequence lt9211_rx_cal_reset_seq[] = {
> + { 0x8120, 0x7f },
> + { 0x8120, 0xff },
> + };
> +
> + const struct reg_sequence lt9211_rx_dig_seq[] = {
> + { 0x8630, 0x85 },
> + /* 0x8588: BIT 6 set = MIPI-RX, BIT 4 unset = LVDS-TX */
> + { 0x8588, 0x40 },
> + { 0x85ff, 0xd0 },
> + { REG_DSI_LANE, REG_DSI_LANE_COUNT(ctx->dsi->lanes) },
> + { 0xd002, 0x05 },
> + };
> +
> + const struct reg_sequence lt9211_rx_div_reset_seq[] = {
> + { 0x810a, 0xc0 },
> + { 0x8120, 0xbf },
> + };
> +
> + const struct reg_sequence lt9211_rx_div_clear_seq[] = {
> + { 0x810a, 0xc1 },
> + { 0x8120, 0xff },
> + };
> +
> + int ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, lt9211_rx_phy_seq,
> + ARRAY_SIZE(lt9211_rx_phy_seq));
> + if (ret)
> + return ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, lt9211_rx_cal_reset_seq,
> + ARRAY_SIZE(lt9211_rx_cal_reset_seq));
> + if (ret)
> + return ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, lt9211_rx_dig_seq,
> + ARRAY_SIZE(lt9211_rx_dig_seq));
> + if (ret)
> + return ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, lt9211_rx_div_reset_seq,
> + ARRAY_SIZE(lt9211_rx_div_reset_seq));
> + if (ret)
> + return ret;
> +
> + usleep_range(10000, 15000);
> +
> + return regmap_multi_reg_write(ctx->regmap, lt9211_rx_div_clear_seq,
> + ARRAY_SIZE(lt9211_rx_div_clear_seq));
> +}
> +
> +static int lt9211_autodetect_rx(struct lt9211 *ctx,
> + const struct drm_display_mode *mode)
> +{
> + u16 width, height;
> + u32 byteclk;
> + u8 buf[5];
> + u8 format;
> + u8 bc[3];
> + int ret;
> +
> + /* Measure ByteClock frequency. */
> + ret = regmap_write(ctx->regmap, 0x8600, 0x01);
> + if (ret)
> + return ret;
> +
> + /* Give the chip time to lock onto RX stream. */
> + msleep(100);
> +
> + /* Read the ByteClock frequency from the chip. */
> + ret = regmap_bulk_read(ctx->regmap, 0x8608, bc, sizeof(bc));
> + if (ret)
> + return ret;
> +
> + /* RX ByteClock in kHz */
> + byteclk = ((bc[0] & 0xf) << 16) | (bc[1] << 8) | bc[2];
> +
> + /* Width/Height/Format Auto-detection */
> + ret = regmap_bulk_read(ctx->regmap, 0xd082, buf, sizeof(buf));
> + if (ret)
> + return ret;
> +
> + width = (buf[0] << 8) | buf[1];
> + height = (buf[3] << 8) | buf[4];
> + format = buf[2] & 0xf;
> +
> + if (format == 0x3) { /* YUV422 16bit */
> + width /= 2;
> + } else if (format == 0xa) { /* RGB888 24bit */
> + width /= 3;
> + } else {
> + dev_err(ctx->dev, "Unsupported DSI pixel format 0x%01x\n",
> + format);
> + return -EINVAL;
> + }
> +
> + if (width != mode->hdisplay) {
> + dev_err(ctx->dev,
> + "RX: Detected DSI width (%d) does not match mode hdisplay (%d)\n",
> + width, mode->hdisplay);
> + return -EINVAL;
> + }
> +
> + if (height != mode->vdisplay) {
> + dev_err(ctx->dev,
> + "RX: Detected DSI height (%d) does not match mode vdisplay (%d)\n",
> + height, mode->vdisplay);
> + return -EINVAL;
> + }
> +
> + dev_dbg(ctx->dev, "RX: %dx%d format=0x%01x byteclock=%d kHz\n",
> + width, height, format, byteclk);
> +
> + return 0;
> +}
> +
> +static int lt9211_configure_timing(struct lt9211 *ctx,
> + const struct drm_display_mode *mode)
> +{
> + const struct reg_sequence lt9211_timing[] = {
> + { 0xd00d, (mode->vtotal >> 8) & 0xff },
> + { 0xd00e, mode->vtotal & 0xff },
> + { 0xd00f, (mode->vdisplay >> 8) & 0xff },
> + { 0xd010, mode->vdisplay & 0xff },
> + { 0xd011, (mode->htotal >> 8) & 0xff },
> + { 0xd012, mode->htotal & 0xff },
> + { 0xd013, (mode->hdisplay >> 8) & 0xff },
> + { 0xd014, mode->hdisplay & 0xff },
> + { 0xd015, (mode->vsync_end - mode->vsync_start) & 0xff },
> + { 0xd016, (mode->hsync_end - mode->hsync_start) & 0xff },
> + { 0xd017, ((mode->vsync_start - mode->vdisplay) >> 8) & 0xff },
> + { 0xd018, (mode->vsync_start - mode->vdisplay) & 0xff },
> + { 0xd019, ((mode->hsync_start - mode->hdisplay) >> 8) & 0xff },
> + { 0xd01a, (mode->hsync_start - mode->hdisplay) & 0xff },
> + };
> +
> + return regmap_multi_reg_write(ctx->regmap, lt9211_timing,
> + ARRAY_SIZE(lt9211_timing));
> +}
> +
> +static int lt9211_configure_plls(struct lt9211 *ctx,
> + const struct drm_display_mode *mode)
> +{
> + const struct reg_sequence lt9211_pcr_seq[] = {
> + { 0xd026, 0x17 },
> + { 0xd027, 0xc3 },
> + { 0xd02d, 0x30 },
> + { 0xd031, 0x10 },
> + { 0xd023, 0x20 },
> + { 0xd038, 0x02 },
> + { 0xd039, 0x10 },
> + { 0xd03a, 0x20 },
> + { 0xd03b, 0x60 },
> + { 0xd03f, 0x04 },
> + { 0xd040, 0x08 },
> + { 0xd041, 0x10 },
> + { 0x810b, 0xee },
> + { 0x810b, 0xfe },
> + };
> +
> + unsigned int pval;
> + int ret;
> +
> + /* DeSSC PLL reference clock is 25 MHz XTal. */
> + ret = regmap_write(ctx->regmap, 0x822d, 0x48);
> + if (ret)
> + return ret;
> +
> + if (mode->clock < 44000) {
> + ret = regmap_write(ctx->regmap, 0x8235, 0x83);
> + } else if (mode->clock < 88000) {
> + ret = regmap_write(ctx->regmap, 0x8235, 0x82);
> + } else if (mode->clock < 176000) {
> + ret = regmap_write(ctx->regmap, 0x8235, 0x81);
> + } else {
> + dev_err(ctx->dev,
> + "Unsupported mode clock (%d kHz) above 176 MHz.\n",
> + mode->clock);
> + return -EINVAL;
> + }
> +
> + if (ret)
> + return ret;
> +
> + /* Wait for the DeSSC PLL to stabilize. */
> + msleep(100);
> +
> + ret = regmap_multi_reg_write(ctx->regmap, lt9211_pcr_seq,
> + ARRAY_SIZE(lt9211_pcr_seq));
> + if (ret)
> + return ret;
> +
> + /* PCR stability test takes seconds. */
> + ret = regmap_read_poll_timeout(ctx->regmap, 0xd087, pval, pval & 0x8,
> + 20000, 10000000);
> + if (ret)
> + dev_err(ctx->dev, "PCR unstable, ret=%i\n", ret);
> +
> + return ret;
> +}
> +
> +static int lt9211_configure_tx(struct lt9211 *ctx, bool jeida,
> + bool bpp24, bool de)
> +{
> + const struct reg_sequence system_lt9211_tx_phy_seq[] = {
> + /* DPI output disable */
> + { 0x8262, 0x00 },
> + /* BIT(7) is LVDS dual-port */
> + { 0x823b, 0x38 | (ctx->lvds_dual_link ? BIT(7) : 0) },
> + { 0x823e, 0x92 },
> + { 0x823f, 0x48 },
> + { 0x8240, 0x31 },
> + { 0x8243, 0x80 },
> + { 0x8244, 0x00 },
> + { 0x8245, 0x00 },
> + { 0x8249, 0x00 },
> + { 0x824a, 0x01 },
> + { 0x824e, 0x00 },
> + { 0x824f, 0x00 },
> + { 0x8250, 0x00 },
> + { 0x8253, 0x00 },
> + { 0x8254, 0x01 },
> + /* LVDS channel order, Odd:Even 0x10..A:B, 0x40..B:A */
> + { 0x8646, ctx->lvds_dual_link_even_odd_swap ? 0x40 : 0x10 },
> + { 0x8120, 0x7b },
> + { 0x816b, 0xff },
> + };
> +
> + const struct reg_sequence system_lt9211_tx_dig_seq[] = {
> + { 0x8559, 0x40 | (jeida ? BIT(7) : 0) |
> + (de ? BIT(5) : 0) | (bpp24 ? BIT(4) : 0) },
> + { 0x855a, 0xaa },
> + { 0x855b, 0xaa },
> + { 0x855c, ctx->lvds_dual_link ? BIT(0) : 0 },
> + { 0x85a1, 0x77 },
> + { 0x8640, 0x40 },
> + { 0x8641, 0x34 },
> + { 0x8642, 0x10 },
> + { 0x8643, 0x23 },
> + { 0x8644, 0x41 },
> + { 0x8645, 0x02 },
> + };
> +
> + const struct reg_sequence system_lt9211_tx_pll_seq[] = {
> + /* TX PLL power down */
> + { 0x8236, 0x01 },
> + { 0x8237, ctx->lvds_dual_link ? 0x2a : 0x29 },
> + { 0x8238, 0x06 },
> + { 0x8239, 0x30 },
> + { 0x823a, 0x8e },
> + { 0x8737, 0x14 },
> + { 0x8713, 0x00 },
> + { 0x8713, 0x80 },
> + };
> +
> + unsigned int pval;
> + int ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, system_lt9211_tx_phy_seq,
> + ARRAY_SIZE(system_lt9211_tx_phy_seq));
> + if (ret)
> + return ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, system_lt9211_tx_dig_seq,
> + ARRAY_SIZE(system_lt9211_tx_dig_seq));
> + if (ret)
> + return ret;
> +
> + ret = regmap_multi_reg_write(ctx->regmap, system_lt9211_tx_pll_seq,
> + ARRAY_SIZE(system_lt9211_tx_pll_seq));
> + if (ret)
> + return ret;
> +
> + ret = regmap_read_poll_timeout(ctx->regmap, 0x871f, pval, pval & 0x80,
> + 10000, 1000000);
> + if (ret) {
> + dev_err(ctx->dev, "TX PLL unstable, ret=%i\n", ret);
> + return ret;
> + }
> +
> + ret = regmap_read_poll_timeout(ctx->regmap, 0x8720, pval, pval & 0x80,
> + 10000, 1000000);
> + if (ret) {
> + dev_err(ctx->dev, "TX PLL unstable, ret=%i\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void lt9211_atomic_enable(struct drm_bridge *bridge,
> + struct drm_bridge_state *old_bridge_state)
> +{
> + struct lt9211 *ctx = bridge_to_lt9211(bridge);
> + struct drm_atomic_state *state = old_bridge_state->base.state;
> + const struct drm_bridge_state *bridge_state;
> + const struct drm_crtc_state *crtc_state;
> + const struct drm_display_mode *mode;
> + struct drm_connector *connector;
> + struct drm_crtc *crtc;
> + bool lvds_format_24bpp;
> + bool lvds_format_jeida;
> + u32 bus_flags;
> + int ret;
> +
> + ret = regulator_enable(ctx->vccio);
> + if (ret) {
> + dev_err(ctx->dev, "Failed to enable vccio: %d\n", ret);
> + return;
> + }
> +
> + /* Deassert reset */
> + gpiod_set_value(ctx->reset_gpio, 1);
> + usleep_range(20000, 21000); /* Very long post-reset delay. */
> +
> + /* Get the LVDS format from the bridge state. */
> + bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
> + bus_flags = bridge_state->output_bus_cfg.flags;
> +
> + switch (bridge_state->output_bus_cfg.format) {
> + case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
> + lvds_format_24bpp = false;
> + lvds_format_jeida = true;
> + break;
> + case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
> + lvds_format_24bpp = true;
> + lvds_format_jeida = true;
> + break;
> + case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
> + lvds_format_24bpp = true;
> + lvds_format_jeida = false;
> + break;
> + default:
> + /*
> + * Some bridges still don't set the correct
> + * LVDS bus pixel format, use SPWG24 default
> + * format until those are fixed.
> + */
> + lvds_format_24bpp = true;
> + lvds_format_jeida = false;
> + dev_warn(ctx->dev,
> + "Unsupported LVDS bus format 0x%04x, please check output bridge driver. Falling back to SPWG24.\n",
> + bridge_state->output_bus_cfg.format);
> + break;
> + }
> +
> + /*
> + * Retrieve the CRTC adjusted mode. This requires a little dance to go
> + * from the bridge to the encoder, to the connector and to the CRTC.
> + */
> + connector = drm_atomic_get_new_connector_for_encoder(state,
> + bridge->encoder);
> + crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
> + crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> + mode = &crtc_state->adjusted_mode;
> +
> + ret = lt9211_read_chipid(ctx);
> + if (ret)
> + return;
> +
> + ret = lt9211_system_init(ctx);
> + if (ret)
> + return;
> +
> + ret = lt9211_configure_rx(ctx);
> + if (ret)
> + return;
> +
> + ret = lt9211_autodetect_rx(ctx, mode);
> + if (ret)
> + return;
> +
> + ret = lt9211_configure_timing(ctx, mode);
> + if (ret)
> + return;
> +
> + ret = lt9211_configure_plls(ctx, mode);
> + if (ret)
> + return;
> +
> + ret = lt9211_configure_tx(ctx, lvds_format_jeida, lvds_format_24bpp,
> + bus_flags & DRM_BUS_FLAG_DE_HIGH);
> + if (ret)
> + return;
> +
> + dev_dbg(ctx->dev, "LT9211 enabled.\n");
> +}
> +
> +static void lt9211_atomic_disable(struct drm_bridge *bridge,
> + struct drm_bridge_state *old_bridge_state)
> +{
> + struct lt9211 *ctx = bridge_to_lt9211(bridge);
> + int ret;
> +
> + /*
> + * Put the chip in reset, pull nRST line low,
> + * and assure lengthy 10ms reset low timing.
> + */
> + gpiod_set_value(ctx->reset_gpio, 0);
> + usleep_range(10000, 11000); /* Very long reset duration. */
> +
> + ret = regulator_disable(ctx->vccio);
> + if (ret)
> + dev_err(ctx->dev, "Failed to disable vccio: %d\n", ret);
> +
> + regcache_mark_dirty(ctx->regmap);
> +}
> +
> +static enum drm_mode_status
> +lt9211_mode_valid(struct drm_bridge *bridge,
> + const struct drm_display_info *info,
> + const struct drm_display_mode *mode)
> +{
> + /* LVDS output clock range 25..176 MHz */
> + if (mode->clock < 25000)
> + return MODE_CLOCK_LOW;
> + if (mode->clock > 176000)
> + return MODE_CLOCK_HIGH;
> +
> + return MODE_OK;
> +}
> +
> +#define MAX_INPUT_SEL_FORMATS 1
> +
> +static u32 *
> +lt9211_atomic_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)
> +{
> + u32 *input_fmts;
> +
> + *num_input_fmts = 0;
> +
> + input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
> + GFP_KERNEL);
> + if (!input_fmts)
> + return NULL;
> +
> + /* This is the DSI-end bus format */
> + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
> + *num_input_fmts = 1;
> +
> + return input_fmts;
> +}
> +
> +static const struct drm_bridge_funcs lt9211_funcs = {
> + .attach = lt9211_attach,
> + .mode_valid = lt9211_mode_valid,
> + .atomic_enable = lt9211_atomic_enable,
> + .atomic_disable = lt9211_atomic_disable,
> + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> + .atomic_get_input_bus_fmts = lt9211_atomic_get_input_bus_fmts,
> + .atomic_reset = drm_atomic_helper_bridge_reset,
> +};
> +
> +static int lt9211_parse_dt(struct lt9211 *ctx)
> +{
> + struct device_node *port2, *port3;
> + struct drm_bridge *panel_bridge;
> + struct device *dev = ctx->dev;
> + struct drm_panel *panel;
> + int dual_link;
> + int ret;
> +
> + ctx->vccio = devm_regulator_get(dev, "vccio");
> + if (IS_ERR(ctx->vccio))
> + return dev_err_probe(dev, PTR_ERR(ctx->vccio),
> + "Failed to get supply 'vccio'\n");
> +
> + ctx->lvds_dual_link = false;
> + ctx->lvds_dual_link_even_odd_swap = false;
> +
> + port2 = of_graph_get_port_by_id(dev->of_node, 2);
> + port3 = of_graph_get_port_by_id(dev->of_node, 3);
> + dual_link = drm_of_lvds_get_dual_link_pixel_order(port2, port3);
> + of_node_put(port2);
> + of_node_put(port3);
> +
> + if (dual_link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS) {
> + ctx->lvds_dual_link = true;
> + /* Odd pixels to LVDS Channel A, even pixels to B */
> + ctx->lvds_dual_link_even_odd_swap = false;
> + } else if (dual_link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {
> + ctx->lvds_dual_link = true;
> + /* Even pixels to LVDS Channel A, odd pixels to B */
> + ctx->lvds_dual_link_even_odd_swap = true;
> + }
> +
> + ret = drm_of_find_panel_or_bridge(dev->of_node, 2, 0, &panel, &panel_bridge);
> + if (ret < 0)
> + return ret;
> + if (panel) {
> + panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> + if (IS_ERR(panel_bridge))
> + return PTR_ERR(panel_bridge);
> + }
> +
> + ctx->panel_bridge = panel_bridge;
> +
> + return 0;
> +}
> +
> +static int lt9211_host_attach(struct lt9211 *ctx)
> +{
> + const struct mipi_dsi_device_info info = {
> + .type = "lt9211",
> + .channel = 0,
> + .node = NULL,
> + };
> + struct device *dev = ctx->dev;
> + struct device_node *host_node;
> + struct device_node *endpoint;
> + struct mipi_dsi_device *dsi;
> + struct mipi_dsi_host *host;
> + int dsi_lanes;
> + int ret;
> +
> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
> + host_node = of_graph_get_remote_port_parent(endpoint);
> + host = of_find_mipi_dsi_host_by_node(host_node);
> + of_node_put(host_node);
> + of_node_put(endpoint);
> +
> + if (!host)
> + return -EPROBE_DEFER;
> +
> + if (dsi_lanes < 0 || dsi_lanes > 4)
> + return -EINVAL;
> +
> + dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
> + if (IS_ERR(dsi))
> + return dev_err_probe(dev, PTR_ERR(dsi),
> + "failed to create dsi device\n");
> +
> + ctx->dsi = dsi;
> +
> + dsi->lanes = dsi_lanes;
> + dsi->format = MIPI_DSI_FMT_RGB888;
> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
> + MIPI_DSI_MODE_VIDEO_HSE;
> +
> + ret = devm_mipi_dsi_attach(dev, dsi);
> + if (ret < 0) {
> + dev_err(dev, "failed to attach dsi to host: %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int lt9211_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &client->dev;
> + struct lt9211 *ctx;
> + int ret;
> +
> + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> + if (!ctx)
> + return -ENOMEM;
> +
> + ctx->dev = dev;
> +
> + /*
> + * Put the chip in reset, pull nRST line low,
> + * and assure lengthy 10ms reset low timing.
> + */
> + ctx->reset_gpio = devm_gpiod_get_optional(ctx->dev, "reset",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(ctx->reset_gpio))
> + return PTR_ERR(ctx->reset_gpio);
> +
> + usleep_range(10000, 11000); /* Very long reset duration. */
> +
> + ret = lt9211_parse_dt(ctx);
> + if (ret)
> + return ret;
> +
> + ctx->regmap = devm_regmap_init_i2c(client, <9211_regmap_config);
> + if (IS_ERR(ctx->regmap))
> + return PTR_ERR(ctx->regmap);
> +
> + dev_set_drvdata(dev, ctx);
> + i2c_set_clientdata(client, ctx);
> +
> + ctx->bridge.funcs = <9211_funcs;
> + ctx->bridge.of_node = dev->of_node;
> + drm_bridge_add(&ctx->bridge);
> +
> + ret = lt9211_host_attach(ctx);
> + if (ret)
> + drm_bridge_remove(&ctx->bridge);
> +
> + return ret;
> +}
> +
> +static int lt9211_remove(struct i2c_client *client)
> +{
> + struct lt9211 *ctx = i2c_get_clientdata(client);
> +
> + drm_bridge_remove(&ctx->bridge);
> +
> + return 0;
> +}
> +
> +static struct i2c_device_id lt9211_id[] = {
> + { "lontium,lt9211" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(i2c, lt9211_id);
> +
> +static const struct of_device_id lt9211_match_table[] = {
> + { .compatible = "lontium,lt9211" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, lt9211_match_table);
> +
> +static struct i2c_driver lt9211_driver = {
> + .probe = lt9211_probe,
> + .remove = lt9211_remove,
> + .id_table = lt9211_id,
> + .driver = {
> + .name = "lt9211",
> + .of_match_table = lt9211_match_table,
> + },
> +};
> +module_i2c_driver(lt9211_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marex at denx.de>");
> +MODULE_DESCRIPTION("Lontium LT9211 DSI/LVDS/DPI bridge driver");
> +MODULE_LICENSE("GPL");
> --
> 2.35.1
I think some of the registers could be named, but overall I'm quite
happy with this driver.
Reviewed-by: Robert Foss <robert.foss at linaro.org>
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