[PATCH V4 2/2] drm/bridge: ti-sn65dsi83: Add TI SN65DSI83 and SN65DSI84 driver

Frieder Schrempf frieder.schrempf at kontron.de
Mon May 10 08:48:52 UTC 2021


On 08.05.21 22:22, Marek Vasut wrote:
> Add driver for TI SN65DSI83 Single-link DSI to Single-link LVDS bridge
> and TI SN65DSI84 Single-link DSI to Dual-link or 2x Single-link LVDS
> bridge. TI SN65DSI85 is unsupported due to lack of hardware to test on,
> but easy to add.
> 
> The driver operates the chip via I2C bus. Currently the LVDS clock are
> always derived from DSI clock lane, which is the usual mode of operation.
> Support for clock from external oscillator is not implemented, but it is
> easy to add if ever needed. Only RGB888 pixel format is implemented, the
> LVDS666 is not supported, but could be added if needed.
> 
> Reviewed-by: Linus Walleij <linus.walleij at linaro.org>
> Reviewed-by: Frieder Schrempf <frieder.schrempf at kontron.de>
> Tested-by: Frieder Schrempf <frieder.schrempf at kontron.de>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Douglas Anderson <dianders at chromium.org>
> Cc: Jagan Teki <jagan at amarulasolutions.com>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Linus Walleij <linus.walleij at linaro.org>
> Cc: Loic Poulain <loic.poulain at linaro.org>
> Cc: Philippe Schenker <philippe.schenker at toradex.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Stephen Boyd <swboyd at chromium.org>
> Cc: Valentin Raevsky <valentin at compulab.co.il>
> To: dri-devel at lists.freedesktop.org
> ---
> V2: - Use dev_err_probe()
>     - Set REG_RC_RESET as volatile
>     - Wait for PLL stabilization by polling REG_RC_LVDS_PLL
>     - Use ctx->mode = *adj instead of *mode in sn65dsi83_mode_set
>     - Add tested DSI84 support in dual-link mode
>     - Correctly set VCOM
>     - Fill in missing DSI CHB and LVDS CHB bits from DSI84 and DSI85
>       datasheets, with that all the reserved bits make far more sense
>       as the DSI83 and DSI84 seems to be reduced version of DSI85
> V3: - Handle the dual-link LVDS with two port panel or bridge
> V4: - Add RB from Linus Walleij
>     - Rename REG_DSI_LANE_LVDS_LINK_CFG_DUAL to
>       REG_DSI_LANE_DSI_CHANNEL_MODE_SINGLE and fill in the remaining
>       DSI link options from DSI85 datasheet. DSI85 can do dual and 2x
>       single DSI mode, but DSI85 is currently unsupported by the
>       driver. Add a comment about DSI85, so that all the places which
>       need to be adjusted for DSI85 are marked accordingly.
>     - Add REG_DSI_LANE_LEFT_RIGHT_PIXELS bit for DSI
>     - Add handling for JEIDA18/JEIDA24/SPWG24 LVDS formats. Use SPWG24
>       as fallback on output bridges until they are all fixed.
>     - Patch DSI bus format to fixed RGB888_1X24 instead of passing
>       through the LVDS bus format.

I just want to report that v4 now handles my panel with MEDIA_BUS_FMT_RGB888_1X7X4_SPWG correctly. Thanks for coming up with this solution. Looks good to me.

> ---
>  drivers/gpu/drm/bridge/Kconfig        |  10 +
>  drivers/gpu/drm/bridge/Makefile       |   1 +
>  drivers/gpu/drm/bridge/ti-sn65dsi83.c | 698 ++++++++++++++++++++++++++
>  3 files changed, 709 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi83.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e83b8ad0d71b..32204c5f25b7 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -278,6 +278,16 @@ config DRM_TI_TFP410
>  	help
>  	  Texas Instruments TFP410 DVI/HDMI Transmitter driver
>  
> +config DRM_TI_SN65DSI83
> +	tristate "TI SN65DSI83 and SN65DSI84 DSI to LVDS bridge"
> +	depends on OF
> +	select DRM_KMS_HELPER
> +	select REGMAP_I2C
> +	select DRM_PANEL
> +	select DRM_MIPI_DSI
> +	help
> +	  Texas Instruments SN65DSI83 and SN65DSI84 DSI to LVDS Bridge driver
> +
>  config DRM_TI_SN65DSI86
>  	tristate "TI SN65DSI86 DSI to eDP bridge"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index b00f3b2ad572..7bb4c9df0415 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> +obj-$(CONFIG_DRM_TI_SN65DSI83) += ti-sn65dsi83.o
>  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
>  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> new file mode 100644
> index 000000000000..1a0a71fbe91d
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> @@ -0,0 +1,698 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TI SN65DSI83,84,85 driver
> + *
> + * Currently supported:
> + * - SN65DSI83
> + *   = 1x Single-link DSI ~ 1x Single-link LVDS
> + *   - Supported
> + *   - Single-link LVDS mode tested
> + * - SN65DSI84
> + *   = 1x Single-link DSI ~ 2x Single-link or 1x Dual-link LVDS
> + *   - Supported
> + *   - Dual-link LVDS mode tested
> + *   - 2x Single-link LVDS mode unsupported
> + *     (should be easy to add by someone who has the HW)
> + * - SN65DSI85
> + *   = 2x Single-link or 1x Dual-link DSI ~ 2x Single-link or 1x Dual-link LVDS
> + *   - Unsupported
> + *     (should be easy to add by someone who has the HW)
> + *
> + * Copyright (C) 2021 Marek Vasut <marex at denx.de>
> + *
> + * Based on previous work of:
> + * Valentin Raevsky <valentin at compulab.co.il>
> + * Philippe Schenker <philippe.schenker at toradex.com>
> + */
> +
> +#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 <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>
> +
> +/* ID registers */
> +#define REG_ID(n)				(0x00 + (n))
> +/* Reset and clock registers */
> +#define REG_RC_RESET				0x09
> +#define  REG_RC_RESET_SOFT_RESET		BIT(0)
> +#define REG_RC_LVDS_PLL				0x0a
> +#define  REG_RC_LVDS_PLL_PLL_EN_STAT		BIT(7)
> +#define  REG_RC_LVDS_PLL_LVDS_CLK_RANGE(n)	(((n) & 0x7) << 1)
> +#define  REG_RC_LVDS_PLL_HS_CLK_SRC_DPHY	BIT(0)
> +#define REG_RC_DSI_CLK				0x0b
> +#define  REG_RC_DSI_CLK_DSI_CLK_DIVIDER(n)	(((n) & 0x1f) << 3)
> +#define  REG_RC_DSI_CLK_REFCLK_MULTIPLIER(n)	((n) & 0x3)
> +#define REG_RC_PLL_EN				0x0d
> +#define  REG_RC_PLL_EN_PLL_EN			BIT(0)
> +/* DSI registers */
> +#define REG_DSI_LANE				0x10
> +#define  REG_DSI_LANE_LEFT_RIGHT_PIXELS		BIT(7)	/* DSI85-only */
> +#define  REG_DSI_LANE_DSI_CHANNEL_MODE_DUAL	0	/* DSI85-only */
> +#define  REG_DSI_LANE_DSI_CHANNEL_MODE_2SINGLE	BIT(6)	/* DSI85-only */
> +#define  REG_DSI_LANE_DSI_CHANNEL_MODE_SINGLE	BIT(5)
> +#define  REG_DSI_LANE_CHA_DSI_LANES(n)		(((n) & 0x3) << 3)
> +#define  REG_DSI_LANE_CHB_DSI_LANES(n)		(((n) & 0x3) << 1)
> +#define  REG_DSI_LANE_SOT_ERR_TOL_DIS		BIT(0)
> +#define REG_DSI_EQ				0x11
> +#define  REG_DSI_EQ_CHA_DSI_DATA_EQ(n)		(((n) & 0x3) << 6)
> +#define  REG_DSI_EQ_CHA_DSI_CLK_EQ(n)		(((n) & 0x3) << 2)
> +#define REG_DSI_CLK				0x12
> +#define  REG_DSI_CLK_CHA_DSI_CLK_RANGE(n)	((n) & 0xff)
> +/* LVDS registers */
> +#define REG_LVDS_FMT				0x18
> +#define  REG_LVDS_FMT_DE_NEG_POLARITY		BIT(7)
> +#define  REG_LVDS_FMT_HS_NEG_POLARITY		BIT(6)
> +#define  REG_LVDS_FMT_VS_NEG_POLARITY		BIT(5)
> +#define  REG_LVDS_FMT_LVDS_LINK_CFG		BIT(4)	/* 0:AB 1:A-only */
> +#define  REG_LVDS_FMT_CHA_24BPP_MODE		BIT(3)
> +#define  REG_LVDS_FMT_CHB_24BPP_MODE		BIT(2)
> +#define  REG_LVDS_FMT_CHA_24BPP_FORMAT1		BIT(1)
> +#define  REG_LVDS_FMT_CHB_24BPP_FORMAT1		BIT(0)
> +#define REG_LVDS_VCOM				0x19
> +#define  REG_LVDS_VCOM_CHA_LVDS_VOCM		BIT(6)
> +#define  REG_LVDS_VCOM_CHB_LVDS_VOCM		BIT(4)
> +#define  REG_LVDS_VCOM_CHA_LVDS_VOD_SWING(n)	(((n) & 0x3) << 2)
> +#define  REG_LVDS_VCOM_CHB_LVDS_VOD_SWING(n)	((n) & 0x3)
> +#define REG_LVDS_LANE				0x1a
> +#define  REG_LVDS_LANE_EVEN_ODD_SWAP		BIT(6)
> +#define  REG_LVDS_LANE_CHA_REVERSE_LVDS		BIT(5)
> +#define  REG_LVDS_LANE_CHB_REVERSE_LVDS		BIT(4)
> +#define  REG_LVDS_LANE_CHA_LVDS_TERM		BIT(1)
> +#define  REG_LVDS_LANE_CHB_LVDS_TERM		BIT(0)
> +#define REG_LVDS_CM				0x1b
> +#define  REG_LVDS_CM_CHA_LVDS_CM_ADJUST(n)	(((n) & 0x3) << 4)
> +#define  REG_LVDS_CM_CHB_LVDS_CM_ADJUST(n)	((n) & 0x3)
> +/* Video registers */
> +#define REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW	0x20
> +#define REG_VID_CHA_ACTIVE_LINE_LENGTH_HIGH	0x21
> +#define REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW	0x24
> +#define REG_VID_CHA_VERTICAL_DISPLAY_SIZE_HIGH	0x25
> +#define REG_VID_CHA_SYNC_DELAY_LOW		0x28
> +#define REG_VID_CHA_SYNC_DELAY_HIGH		0x29
> +#define REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW	0x2c
> +#define REG_VID_CHA_HSYNC_PULSE_WIDTH_HIGH	0x2d
> +#define REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW	0x30
> +#define REG_VID_CHA_VSYNC_PULSE_WIDTH_HIGH	0x31
> +#define REG_VID_CHA_HORIZONTAL_BACK_PORCH	0x34
> +#define REG_VID_CHA_VERTICAL_BACK_PORCH		0x36
> +#define REG_VID_CHA_HORIZONTAL_FRONT_PORCH	0x38
> +#define REG_VID_CHA_VERTICAL_FRONT_PORCH	0x3a
> +#define REG_VID_CHA_TEST_PATTERN		0x3c
> +/* IRQ registers */
> +#define REG_IRQ_GLOBAL				0xe0
> +#define  REG_IRQ_GLOBAL_IRQ_EN			BIT(0)
> +#define REG_IRQ_EN				0xe1
> +#define  REG_IRQ_EN_CHA_SYNCH_ERR_EN		BIT(7)
> +#define  REG_IRQ_EN_CHA_CRC_ERR_EN		BIT(6)
> +#define  REG_IRQ_EN_CHA_UNC_ECC_ERR_EN		BIT(5)
> +#define  REG_IRQ_EN_CHA_COR_ECC_ERR_EN		BIT(4)
> +#define  REG_IRQ_EN_CHA_LLP_ERR_EN		BIT(3)
> +#define  REG_IRQ_EN_CHA_SOT_BIT_ERR_EN		BIT(2)
> +#define  REG_IRQ_EN_CHA_PLL_UNLOCK_EN		BIT(0)
> +#define REG_IRQ_STAT				0xe5
> +#define  REG_IRQ_STAT_CHA_SYNCH_ERR		BIT(7)
> +#define  REG_IRQ_STAT_CHA_CRC_ERR		BIT(6)
> +#define  REG_IRQ_STAT_CHA_UNC_ECC_ERR		BIT(5)
> +#define  REG_IRQ_STAT_CHA_COR_ECC_ERR		BIT(4)
> +#define  REG_IRQ_STAT_CHA_LLP_ERR		BIT(3)
> +#define  REG_IRQ_STAT_CHA_SOT_BIT_ERR		BIT(2)
> +#define  REG_IRQ_STAT_CHA_PLL_UNLOCK		BIT(0)
> +
> +enum sn65dsi83_model {
> +	MODEL_SN65DSI83,
> +	MODEL_SN65DSI84,
> +};
> +
> +struct sn65dsi83 {
> +	struct drm_bridge		bridge;
> +	struct drm_display_mode		mode;
> +	struct device			*dev;
> +	struct regmap			*regmap;
> +	struct device_node		*host_node;
> +	struct mipi_dsi_device		*dsi;
> +	struct drm_bridge		*panel_bridge;
> +	struct gpio_desc		*enable_gpio;
> +	int				dsi_lanes;
> +	bool				lvds_dual_link;
> +	bool				lvds_dual_link_even_odd_swap;
> +	bool				lvds_format_24bpp;
> +	bool				lvds_format_jeida;
> +};
> +
> +static const struct regmap_range sn65dsi83_readable_ranges[] = {
> +	regmap_reg_range(REG_ID(0), REG_ID(8)),
> +	regmap_reg_range(REG_RC_LVDS_PLL, REG_RC_DSI_CLK),
> +	regmap_reg_range(REG_RC_PLL_EN, REG_RC_PLL_EN),
> +	regmap_reg_range(REG_DSI_LANE, REG_DSI_CLK),
> +	regmap_reg_range(REG_LVDS_FMT, REG_LVDS_CM),
> +	regmap_reg_range(REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW,
> +			 REG_VID_CHA_ACTIVE_LINE_LENGTH_HIGH),
> +	regmap_reg_range(REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW,
> +			 REG_VID_CHA_VERTICAL_DISPLAY_SIZE_HIGH),
> +	regmap_reg_range(REG_VID_CHA_SYNC_DELAY_LOW,
> +			 REG_VID_CHA_SYNC_DELAY_HIGH),
> +	regmap_reg_range(REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW,
> +			 REG_VID_CHA_HSYNC_PULSE_WIDTH_HIGH),
> +	regmap_reg_range(REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW,
> +			 REG_VID_CHA_VSYNC_PULSE_WIDTH_HIGH),
> +	regmap_reg_range(REG_VID_CHA_HORIZONTAL_BACK_PORCH,
> +			 REG_VID_CHA_HORIZONTAL_BACK_PORCH),
> +	regmap_reg_range(REG_VID_CHA_VERTICAL_BACK_PORCH,
> +			 REG_VID_CHA_VERTICAL_BACK_PORCH),
> +	regmap_reg_range(REG_VID_CHA_HORIZONTAL_FRONT_PORCH,
> +			 REG_VID_CHA_HORIZONTAL_FRONT_PORCH),
> +	regmap_reg_range(REG_VID_CHA_VERTICAL_FRONT_PORCH,
> +			 REG_VID_CHA_VERTICAL_FRONT_PORCH),
> +	regmap_reg_range(REG_VID_CHA_TEST_PATTERN, REG_VID_CHA_TEST_PATTERN),
> +	regmap_reg_range(REG_IRQ_GLOBAL, REG_IRQ_EN),
> +	regmap_reg_range(REG_IRQ_STAT, REG_IRQ_STAT),
> +};
> +
> +static const struct regmap_access_table sn65dsi83_readable_table = {
> +	.yes_ranges = sn65dsi83_readable_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(sn65dsi83_readable_ranges),
> +};
> +
> +static const struct regmap_range sn65dsi83_writeable_ranges[] = {
> +	regmap_reg_range(REG_RC_RESET, REG_RC_DSI_CLK),
> +	regmap_reg_range(REG_RC_PLL_EN, REG_RC_PLL_EN),
> +	regmap_reg_range(REG_DSI_LANE, REG_DSI_CLK),
> +	regmap_reg_range(REG_LVDS_FMT, REG_LVDS_CM),
> +	regmap_reg_range(REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW,
> +			 REG_VID_CHA_ACTIVE_LINE_LENGTH_HIGH),
> +	regmap_reg_range(REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW,
> +			 REG_VID_CHA_VERTICAL_DISPLAY_SIZE_HIGH),
> +	regmap_reg_range(REG_VID_CHA_SYNC_DELAY_LOW,
> +			 REG_VID_CHA_SYNC_DELAY_HIGH),
> +	regmap_reg_range(REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW,
> +			 REG_VID_CHA_HSYNC_PULSE_WIDTH_HIGH),
> +	regmap_reg_range(REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW,
> +			 REG_VID_CHA_VSYNC_PULSE_WIDTH_HIGH),
> +	regmap_reg_range(REG_VID_CHA_HORIZONTAL_BACK_PORCH,
> +			 REG_VID_CHA_HORIZONTAL_BACK_PORCH),
> +	regmap_reg_range(REG_VID_CHA_VERTICAL_BACK_PORCH,
> +			 REG_VID_CHA_VERTICAL_BACK_PORCH),
> +	regmap_reg_range(REG_VID_CHA_HORIZONTAL_FRONT_PORCH,
> +			 REG_VID_CHA_HORIZONTAL_FRONT_PORCH),
> +	regmap_reg_range(REG_VID_CHA_VERTICAL_FRONT_PORCH,
> +			 REG_VID_CHA_VERTICAL_FRONT_PORCH),
> +	regmap_reg_range(REG_VID_CHA_TEST_PATTERN, REG_VID_CHA_TEST_PATTERN),
> +	regmap_reg_range(REG_IRQ_GLOBAL, REG_IRQ_EN),
> +	regmap_reg_range(REG_IRQ_STAT, REG_IRQ_STAT),
> +};
> +
> +static const struct regmap_access_table sn65dsi83_writeable_table = {
> +	.yes_ranges = sn65dsi83_writeable_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(sn65dsi83_writeable_ranges),
> +};
> +
> +static const struct regmap_range sn65dsi83_volatile_ranges[] = {
> +	regmap_reg_range(REG_RC_RESET, REG_RC_RESET),
> +	regmap_reg_range(REG_RC_LVDS_PLL, REG_RC_LVDS_PLL),
> +	regmap_reg_range(REG_IRQ_STAT, REG_IRQ_STAT),
> +};
> +
> +static const struct regmap_access_table sn65dsi83_volatile_table = {
> +	.yes_ranges = sn65dsi83_volatile_ranges,
> +	.n_yes_ranges = ARRAY_SIZE(sn65dsi83_volatile_ranges),
> +};
> +
> +static const struct regmap_config sn65dsi83_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.rd_table = &sn65dsi83_readable_table,
> +	.wr_table = &sn65dsi83_writeable_table,
> +	.volatile_table = &sn65dsi83_volatile_table,
> +	.cache_type = REGCACHE_RBTREE,
> +	.max_register = REG_IRQ_STAT,
> +};
> +
> +static struct sn65dsi83 *bridge_to_sn65dsi83(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct sn65dsi83, bridge);
> +}
> +
> +static int sn65dsi83_attach(struct drm_bridge *bridge,
> +			    enum drm_bridge_attach_flags flags)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +	struct device *dev = ctx->dev;
> +	struct mipi_dsi_device *dsi;
> +	struct mipi_dsi_host *host;
> +	int ret = 0;
> +
> +	const struct mipi_dsi_device_info info = {
> +		.type = "sn65dsi83",
> +		.channel = 0,
> +		.node = NULL,
> +	};
> +
> +	host = of_find_mipi_dsi_host_by_node(ctx->host_node);
> +	if (!host) {
> +		dev_err(dev, "failed to find dsi host\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	dsi = mipi_dsi_device_register_full(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 = ctx->dsi_lanes;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST;
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to attach dsi to host\n");
> +		goto err_dsi_attach;
> +	}
> +
> +	return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
> +				 &ctx->bridge, flags);
> +
> +err_dsi_attach:
> +	mipi_dsi_device_unregister(dsi);
> +	return ret;
> +}
> +
> +static void sn65dsi83_pre_enable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +
> +	/*
> +	 * Reset the chip, pull EN line low for t_reset=10ms,
> +	 * then high for t_en=1ms.
> +	 */
> +	regcache_mark_dirty(ctx->regmap);
> +	gpiod_set_value(ctx->enable_gpio, 0);
> +	usleep_range(10000, 11000);
> +	gpiod_set_value(ctx->enable_gpio, 1);
> +	usleep_range(1000, 1100);
> +}
> +
> +static u8 sn65dsi83_get_lvds_range(struct sn65dsi83 *ctx)
> +{
> +	/*
> +	 * The encoding of the LVDS_CLK_RANGE is as follows:
> +	 * 000 - 25 MHz <= LVDS_CLK < 37.5 MHz
> +	 * 001 - 37.5 MHz <= LVDS_CLK < 62.5 MHz
> +	 * 010 - 62.5 MHz <= LVDS_CLK < 87.5 MHz
> +	 * 011 - 87.5 MHz <= LVDS_CLK < 112.5 MHz
> +	 * 100 - 112.5 MHz <= LVDS_CLK < 137.5 MHz
> +	 * 101 - 137.5 MHz <= LVDS_CLK <= 154 MHz
> +	 * which is a range of 12.5MHz..162.5MHz in 50MHz steps, except that
> +	 * the ends of the ranges are clamped to the supported range. Since
> +	 * sn65dsi83_mode_valid() already filters the valid modes and limits
> +	 * the clock to 25..154 MHz, the range calculation can be simplified
> +	 * as follows:
> +	 */
> +	int mode_clock = ctx->mode.clock;
> +
> +	if (ctx->lvds_dual_link)
> +		mode_clock /= 2;
> +
> +	return (mode_clock - 12500) / 25000;
> +}
> +
> +static u8 sn65dsi83_get_dsi_range(struct sn65dsi83 *ctx)
> +{
> +	/*
> +	 * The encoding of the CHA_DSI_CLK_RANGE is as follows:
> +	 * 0x00 through 0x07 - Reserved
> +	 * 0x08 - 40 <= DSI_CLK < 45 MHz
> +	 * 0x09 - 45 <= DSI_CLK < 50 MHz
> +	 * ...
> +	 * 0x63 - 495 <= DSI_CLK < 500 MHz
> +	 * 0x64 - 500 MHz
> +	 * 0x65 through 0xFF - Reserved
> +	 * which is DSI clock in 5 MHz steps, clamped to 40..500 MHz.
> +	 * The DSI clock are calculated as:
> +	 *  DSI_CLK = mode clock * bpp / dsi_data_lanes / 2
> +	 * the 2 is there because the bus is DDR.
> +	 */
> +	return DIV_ROUND_UP(clamp((unsigned int)ctx->mode.clock *
> +			    mipi_dsi_pixel_format_to_bpp(ctx->dsi->format) /
> +			    ctx->dsi_lanes / 2, 40000U, 500000U), 5000U);
> +}
> +
> +static u8 sn65dsi83_get_dsi_div(struct sn65dsi83 *ctx)
> +{
> +	/* The divider is (DSI_CLK / LVDS_CLK) - 1, which really is: */
> +	unsigned int dsi_div = mipi_dsi_pixel_format_to_bpp(ctx->dsi->format);
> +
> +	dsi_div /= ctx->dsi_lanes;
> +
> +	if (!ctx->lvds_dual_link)
> +		dsi_div /= 2;
> +
> +	return dsi_div - 1;
> +}
> +
> +static void sn65dsi83_enable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +	unsigned int pval;
> +	u16 val;
> +	int ret;
> +
> +	/* Clear reset, disable PLL */
> +	regmap_write(ctx->regmap, REG_RC_RESET, 0x00);
> +	regmap_write(ctx->regmap, REG_RC_PLL_EN, 0x00);
> +
> +	/* Reference clock derived from DSI link clock. */
> +	regmap_write(ctx->regmap, REG_RC_LVDS_PLL,
> +		REG_RC_LVDS_PLL_LVDS_CLK_RANGE(sn65dsi83_get_lvds_range(ctx)) |
> +		REG_RC_LVDS_PLL_HS_CLK_SRC_DPHY);
> +	regmap_write(ctx->regmap, REG_DSI_CLK,
> +		REG_DSI_CLK_CHA_DSI_CLK_RANGE(sn65dsi83_get_dsi_range(ctx)));
> +	regmap_write(ctx->regmap, REG_RC_DSI_CLK,
> +		REG_RC_DSI_CLK_DSI_CLK_DIVIDER(sn65dsi83_get_dsi_div(ctx)));
> +
> +	/* Set number of DSI lanes and LVDS link config. */
> +	regmap_write(ctx->regmap, REG_DSI_LANE,
> +		REG_DSI_LANE_DSI_CHANNEL_MODE_SINGLE |
> +		REG_DSI_LANE_CHA_DSI_LANES(~(ctx->dsi_lanes - 1)) |
> +		/* CHB is DSI85-only, set to default on DSI83/DSI84 */
> +		REG_DSI_LANE_CHB_DSI_LANES(3));
> +	/* No equalization. */
> +	regmap_write(ctx->regmap, REG_DSI_EQ, 0x00);
> +
> +	/* Set up sync signal polarity. */
> +	val = (ctx->mode.flags & DRM_MODE_FLAG_NHSYNC ?
> +	       REG_LVDS_FMT_HS_NEG_POLARITY : 0) |
> +	      (ctx->mode.flags & DRM_MODE_FLAG_NVSYNC ?
> +	       REG_LVDS_FMT_VS_NEG_POLARITY : 0);
> +
> +	/* Set up bits-per-pixel, 18bpp or 24bpp. */
> +	if (ctx->lvds_format_24bpp) {
> +		val |= REG_LVDS_FMT_CHA_24BPP_MODE;
> +		if (ctx->lvds_dual_link)
> +			val |= REG_LVDS_FMT_CHB_24BPP_MODE;
> +	}
> +
> +	/* Set up LVDS format, JEIDA/Format 1 or SPWG/Format 2 */
> +	if (ctx->lvds_format_jeida) {
> +		val |= REG_LVDS_FMT_CHA_24BPP_FORMAT1;
> +		if (ctx->lvds_dual_link)
> +			val |= REG_LVDS_FMT_CHB_24BPP_FORMAT1;
> +	}
> +
> +	/* Set up LVDS output config (DSI84,DSI85) */
> +	if (!ctx->lvds_dual_link)
> +		val |= REG_LVDS_FMT_LVDS_LINK_CFG;
> +
> +	regmap_write(ctx->regmap, REG_LVDS_FMT, val);
> +	regmap_write(ctx->regmap, REG_LVDS_VCOM, 0x05);
> +	regmap_write(ctx->regmap, REG_LVDS_LANE,
> +		(ctx->lvds_dual_link_even_odd_swap ?
> +		 REG_LVDS_LANE_EVEN_ODD_SWAP : 0) |
> +		REG_LVDS_LANE_CHA_LVDS_TERM |
> +		REG_LVDS_LANE_CHB_LVDS_TERM);
> +	regmap_write(ctx->regmap, REG_LVDS_CM, 0x00);
> +
> +	regmap_bulk_write(ctx->regmap, REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW,
> +			  &ctx->mode.hdisplay, 2);
> +	regmap_bulk_write(ctx->regmap, REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW,
> +			  &ctx->mode.vdisplay, 2);
> +	val = 32 + 1;	/* 32 + 1 pixel clock to ensure proper operation */
> +	regmap_bulk_write(ctx->regmap, REG_VID_CHA_SYNC_DELAY_LOW, &val, 2);
> +	val = ctx->mode.hsync_end - ctx->mode.hsync_start;
> +	regmap_bulk_write(ctx->regmap, REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW,
> +			  &val, 2);
> +	val = ctx->mode.vsync_end - ctx->mode.vsync_start;
> +	regmap_bulk_write(ctx->regmap, REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW,
> +			  &val, 2);
> +	regmap_write(ctx->regmap, REG_VID_CHA_HORIZONTAL_BACK_PORCH,
> +		     ctx->mode.htotal - ctx->mode.hsync_end);
> +	regmap_write(ctx->regmap, REG_VID_CHA_VERTICAL_BACK_PORCH,
> +		     ctx->mode.vtotal - ctx->mode.vsync_end);
> +	regmap_write(ctx->regmap, REG_VID_CHA_HORIZONTAL_FRONT_PORCH,
> +		     ctx->mode.hsync_start - ctx->mode.hdisplay);
> +	regmap_write(ctx->regmap, REG_VID_CHA_VERTICAL_FRONT_PORCH,
> +		     ctx->mode.vsync_start - ctx->mode.vdisplay);
> +	regmap_write(ctx->regmap, REG_VID_CHA_TEST_PATTERN, 0x00);
> +
> +	/* Enable PLL */
> +	regmap_write(ctx->regmap, REG_RC_PLL_EN, REG_RC_PLL_EN_PLL_EN);
> +	usleep_range(3000, 4000);
> +	ret = regmap_read_poll_timeout(ctx->regmap, REG_RC_LVDS_PLL, pval,
> +					pval & REG_RC_LVDS_PLL_PLL_EN_STAT,
> +					1000, 100000);
> +	if (ret) {
> +		dev_err(ctx->dev, "failed to lock PLL, ret=%i\n", ret);
> +		/* On failure, disable PLL again and exit. */
> +		regmap_write(ctx->regmap, REG_RC_PLL_EN, 0x00);
> +		return;
> +	}
> +
> +	/* Trigger reset after CSR register update. */
> +	regmap_write(ctx->regmap, REG_RC_RESET, REG_RC_RESET_SOFT_RESET);
> +
> +	/* Clear all errors that got asserted during initialization. */
> +	regmap_read(ctx->regmap, REG_IRQ_STAT, &pval);
> +	regmap_write(ctx->regmap, REG_IRQ_STAT, pval);
> +}
> +
> +static void sn65dsi83_disable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +
> +	/* Clear reset, disable PLL */
> +	regmap_write(ctx->regmap, REG_RC_RESET, 0x00);
> +	regmap_write(ctx->regmap, REG_RC_PLL_EN, 0x00);
> +}
> +
> +static void sn65dsi83_post_disable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +
> +	/* Put the chip in reset, pull EN line low. */
> +	gpiod_set_value(ctx->enable_gpio, 0);
> +}
> +
> +static enum drm_mode_status
> +sn65dsi83_mode_valid(struct drm_bridge *bridge,
> +		     const struct drm_display_info *info,
> +		     const struct drm_display_mode *mode)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +
> +	/* LVDS output clock range 25..154 MHz */
> +	if (mode->clock < 25000)
> +		return MODE_CLOCK_LOW;
> +	if (mode->clock > 154000)
> +		return MODE_CLOCK_HIGH;
> +
> +	switch (info->bus_formats[0]) {
> +	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
> +		ctx->lvds_format_24bpp = false;
> +		ctx->lvds_format_jeida = false;
> +		break;
> +	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
> +		ctx->lvds_format_24bpp = true;
> +		ctx->lvds_format_jeida = true;
> +		break;
> +	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
> +		ctx->lvds_format_24bpp = true;
> +		ctx->lvds_format_jeida = false;
> +		break;
> +	default:
> +		ctx->lvds_format_24bpp = true;
> +		ctx->lvds_format_jeida = false;
> +		/*
> +		 * Some bridges still don't set the correct LVDS bus pixel
> +		 * format, use SPWG24 default format until those are fixed.
> +		 */
> +		dev_warn(ctx->dev,
> +			"Unsupported LVDS bus format 0x%04x, please check output bridge driver. Falling back to SPWG24.\n",
> +			info->bus_formats[0]);
> +		break;
> +	}
> +
> +	return MODE_OK;
> +}
> +
> +static void sn65dsi83_mode_set(struct drm_bridge *bridge,
> +			       const struct drm_display_mode *mode,
> +			       const struct drm_display_mode *adj)
> +{
> +	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +	u32 input_bus_format = MEDIA_BUS_FMT_RGB888_1X24;
> +	struct drm_encoder *encoder = bridge->encoder;
> +	struct drm_device *ddev = encoder->dev;
> +	struct drm_connector *connector;
> +
> +	/* The DSI format is always RGB888_1X24 */
> +	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
> +		if (connector->encoder != encoder)
> +			continue;
> +
> +		drm_display_info_set_bus_formats(&connector->display_info,
> +						 &input_bus_format, 1);
> +	}
> +
> +	ctx->mode = *adj;
> +}
> +
> +static const struct drm_bridge_funcs sn65dsi83_funcs = {
> +	.attach		= sn65dsi83_attach,
> +	.pre_enable	= sn65dsi83_pre_enable,
> +	.enable		= sn65dsi83_enable,
> +	.disable	= sn65dsi83_disable,
> +	.post_disable	= sn65dsi83_post_disable,
> +	.mode_valid	= sn65dsi83_mode_valid,
> +	.mode_set	= sn65dsi83_mode_set,
> +};
> +
> +static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
> +{
> +	struct drm_bridge *panel_bridge;
> +	struct device *dev = ctx->dev;
> +	struct device_node *endpoint;
> +	struct drm_panel *panel;
> +	int ret;
> +
> +	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
> +	ctx->dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
> +	ctx->host_node = of_graph_get_remote_port_parent(endpoint);
> +	of_node_put(endpoint);
> +
> +	if (ctx->dsi_lanes < 0 || ctx->dsi_lanes > 4)
> +		return -EINVAL;
> +	if (!ctx->host_node)
> +		return -ENODEV;
> +
> +	ctx->lvds_dual_link = false;
> +	ctx->lvds_dual_link_even_odd_swap = false;
> +	if (model != MODEL_SN65DSI83) {
> +		struct device_node *port2, *port3;
> +		int dual_link;
> +
> +		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 sn65dsi83_probe(struct i2c_client *client,
> +			   const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	enum sn65dsi83_model model;
> +	struct sn65dsi83 *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->dev = dev;
> +
> +	if (dev->of_node)
> +		model = (enum sn65dsi83_model)of_device_get_match_data(dev);
> +	else
> +		model = id->driver_data;
> +
> +	ctx->enable_gpio = devm_gpiod_get(ctx->dev, "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->enable_gpio))
> +		return PTR_ERR(ctx->enable_gpio);
> +
> +	ret = sn65dsi83_parse_dt(ctx, model);
> +	if (ret)
> +		return ret;
> +
> +	ctx->regmap = devm_regmap_init_i2c(client, &sn65dsi83_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 = &sn65dsi83_funcs;
> +	ctx->bridge.of_node = dev->of_node;
> +	drm_bridge_add(&ctx->bridge);
> +
> +	return 0;
> +}
> +
> +static int sn65dsi83_remove(struct i2c_client *client)
> +{
> +	struct sn65dsi83 *ctx = i2c_get_clientdata(client);
> +
> +	mipi_dsi_detach(ctx->dsi);
> +	mipi_dsi_device_unregister(ctx->dsi);
> +	drm_bridge_remove(&ctx->bridge);
> +	of_node_put(ctx->host_node);
> +
> +	return 0;
> +}
> +
> +static struct i2c_device_id sn65dsi83_id[] = {
> +	{ "ti,sn65dsi83", MODEL_SN65DSI83 },
> +	{ "ti,sn65dsi84", MODEL_SN65DSI84 },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, sn65dsi83_id);
> +
> +static const struct of_device_id sn65dsi83_match_table[] = {
> +	{ .compatible = "ti,sn65dsi83", .data = (void *)MODEL_SN65DSI83 },
> +	{ .compatible = "ti,sn65dsi84", .data = (void *)MODEL_SN65DSI84 },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, sn65dsi83_match_table);
> +
> +static struct i2c_driver sn65dsi83_driver = {
> +	.probe = sn65dsi83_probe,
> +	.remove = sn65dsi83_remove,
> +	.id_table = sn65dsi83_id,
> +	.driver = {
> +		.name = "sn65dsi83",
> +		.of_match_table = sn65dsi83_match_table,
> +	},
> +};
> +module_i2c_driver(sn65dsi83_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marex at denx.de>");
> +MODULE_DESCRIPTION("TI SN65DSI83 DSI to LVDS bridge driver");
> +MODULE_LICENSE("GPL v2");
> 


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