[V3, 2/2] drm/bridge: ti-sn65dsi83: Add TI SN65DSI83 and SN65DSI84 driver
Mike Looijmans
mike.looijmans at topic.nl
Mon May 17 13:23:12 UTC 2021
Hi Marek,
I'm testing your driver, some remarks below.
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands
T: +31 (0) 499 33 69 69
E: mike.looijmans at topicproducts.com
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On 05-05-2021 12:02, 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.
>
> 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
> 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>
> ---
> 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
> ---
> drivers/gpu/drm/bridge/Kconfig | 10 +
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/ti-sn65dsi83.c | 639 ++++++++++++++++++++++++++
> 3 files changed, 650 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..471df09a1c07
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> @@ -0,0 +1,639 @@
> +// 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_LVDS_LINK_CFG_DUAL BIT(5) /* dual or 2x single */
> +#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;
> +};
> +
> +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);
Taking the chip out of reset here is not needed and may even disrupt
things, as the DSI hasn't set up anything yet so the clock may not be
running. I'd move this all into enable and get rid of the pre_enable
call. Similar for post_disable.
> +}
> +
> +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);
Writing 0 to the RESET register is a no-op. Has no effect whatsoever,
just wasting time and code.
> + 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_LVDS_LINK_CFG_DUAL |
> + 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);
> +
> + /* RGB888 is the only format supported so far. */
> + 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) |
> + REG_LVDS_FMT_CHA_24BPP_MODE;
> + if (ctx->lvds_dual_link)
> + val |= REG_LVDS_FMT_CHB_24BPP_MODE;
> + else
> + 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);
I think this ignores the endian format of the data. So this would only
work on little-endian systems, right?
> + 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);
Just write 0xFF to the IRQ_STAT register. Then there's no need to read
it first.
> +}
> +
> +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);
Writing 0 to the RESET register is a no-op. Has no effect whatsoever,
just wasting time and code.
> + 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);
See my remark on pre_enable, just move this bit into disable.
> +}
> +
> +static enum drm_mode_status
> +sn65dsi83_mode_valid(struct drm_bridge *bridge,
> + const struct drm_display_info *info,
> + const struct drm_display_mode *mode)
> +{
> + /* LVDS output clock range 25..154 MHz */
> + if (mode->clock < 25000)
> + return MODE_CLOCK_LOW;
> + if (mode->clock > 154000)
> + return MODE_CLOCK_HIGH;
> +
> + 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);
> +
> + 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");
--
Mike Looijmans
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