[PATCH v2 2/2] drm: bridge: Add SN65DSI84 DSI to LVDS bridge
Michael Nazzareno Trimarchi
michael at amarulasolutions.com
Wed Feb 3 09:21:17 UTC 2021
Hi
On Wed, Feb 3, 2021 at 8:13 AM Jagan Teki <jagan at amarulasolutions.com> wrote:
>
> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> Texas Instruments.
>
> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> controllers.
>
> Right now the bridge driver is supporting a single link, dual-link
> support requires to initiate I2C Channel B registers.
>
> Tested with STM32MP1 MIPI DSI host design configuration.
>
> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> ---
> Changes for v2:
> - dropped the mdelays between commands as delays in init script in
> datasheet is based Aardvark I2C host adaptor.
> https://e2e.ti.com/support/interface/f/138/t/974276
>
> MAINTAINERS | 6 +
> drivers/gpu/drm/bridge/Kconfig | 19 ++
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/ti-sn65dsi84.c | 457 ++++++++++++++++++++++++++
> 4 files changed, 483 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 12dd1fff2a39..44750ff7640c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5984,6 +5984,12 @@ S: Maintained
> F: Documentation/devicetree/bindings/display/ti/
> F: drivers/gpu/drm/omapdrm/
>
> +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> +M: Jagan Teki <jagan at amarulasolutions.com>
> +S: Maintained
> +F: Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> +F: drivers/gpu/drm/bridge/ti-sn65dsi84.c
> +
> DRM DRIVERS FOR V3D
> M: Eric Anholt <eric at anholt.net>
> S: Supported
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e4110d6ca7b3..6494881bffb3 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -232,6 +232,25 @@ config DRM_TI_TFP410
> help
> Texas Instruments TFP410 DVI/HDMI Transmitter driver
>
> +config DRM_TI_SN65DSI84
> + tristate "TI 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 SN65DSI84 Single Channel DSI to Dual-link LVDS
> + bridge driver.
> +
> + Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> + converts the formatted video data stream to a FlatLink compatible
> + LVDS output operating at pixel clocks operating from 25 MHx to
> + 154 MHz.
> +
> + SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> + four data lanes per link.
> +
> 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 86e7acc76f8d..3906052ef639 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -20,6 +20,7 @@ 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-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
> obj-$(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-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> new file mode 100644
> index 000000000000..27a9074db17e
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> @@ -0,0 +1,457 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 Engicam srl
> + * Copyright (C) 2021 Amarula Solutions(India)
> + * Author: Jagan Teki <jagan at amarulasolutions.com>
> + */
> +
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_mipi_dsi.h>
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +/* sn65dsi84 registers */
> +#define SN65DSI_SOFT_RESET 0x09
> +#define SN65DSI_LVDS_CLK 0x0a
> +#define SN65DSI_CLK_DIV 0x0b
> +#define SN65DSI_CLK_PLL 0x0d
> +#define SN65DSI_DSI_CFG 0x10
> +#define SN65DSI_DSI_CLK_EQ 0x11
> +#define SN65DSI_DSI_CLK_RANGE 0x12
> +#define SN65DSI_LVDS_MODE 0x18
> +#define SN65DSI_CHA_LINE_LO 0x20
> +#define SN65DSI_CHA_LINE_HI 0x21
> +#define SN65DSI_CHA_VIRT_LO 0x24
> +#define SN65DSI_CHA_VIRT_HI 0x25
> +#define SN65DSI_CHA_SYNC_DELAY_LO 0x28
> +#define SN65DSI_CHA_SYNC_DELAY_HI 0x29
> +#define SN65DSI_CHA_HSYNC_WIDTH_LO 0x2c
> +#define SN65DSI_CHA_HSYNC_WIDTH_HI 0x2d
> +#define SN65DSI_CHA_VSYNC_WIDTH_LO 0x30
> +#define SN65DSI_CHA_VSYNC_WIDTH_HI 0x31
> +#define SN65DSI_CHA_HBACK_PORCH 0x34
> +#define SN65DSI_CHA_VBACK_PORCH 0x36
> +#define SN65DSI_CHA_HFRONT_PORCH 0x38
> +#define SN65DSI_CHA_VFRONT_PORCH 0x3a
> +#define SN65DSI_CHA_ERR 0xe5
> +
> +/* sn65dsi register bits */
> +#define SN65DSI_RESET_EN BIT(0)
> +#define SN65DSI_PLL_EN BIT(0)
> +#define SN65DSI_LVDS_CLK_MASK GENMASK(3, 1)
> +#define SN65DSI_LVDS_CLK_SHIFT 1
> +#define SN65DSI_LVDS_CLK_SRC_DSI BIT(0)
> +#define SN65DSI_CLK_DIV_MASK GENMASK(7, 3)
> +#define SN65DSI_CLK_DIV_SHIFT 3
> +#define SN65DSI_DSI_LANE_MASK GENMASK(4, 3)
> +#define SN65DSI_DSI_LANE_SHIFT 3
> +#define SN65DSI_LVDS_LINK_CFG BIT(4)
> +#define SN65DSI_LVDS_CHA_24BPP BIT(3)
> +#define SN65DSI_CHA_LOW_SYNC_DELAY 0x20
> +#define SN65DSI_CHA_HIGH_SYNC_DELAY 0x00
> +
> +struct sn65dsi {
> + struct device *dev;
> + struct drm_bridge bridge;
> + struct drm_bridge *panel_bridge;
> +
> + struct device_node *host_node;
> + struct mipi_dsi_device *dsi;
> + u8 dsi_lanes;
> +
> + struct regmap *regmap;
> + struct gpio_desc *enable;
> +};
I suggest a better name. 3 different families are compatible here
> +
> +static const struct regmap_config sn65dsi_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = SN65DSI_CHA_ERR,
> + .name = "sn65dsi",
> + .cache_type = REGCACHE_RBTREE,
> +};
> +
> +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct sn65dsi, bridge);
> +}
> +
> +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> +{
> + return &bridge->encoder->crtc->state->mode;
> +}
> +
> +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> + struct drm_display_mode *mode)
> +{
> + u32 hsync_len, hfront_porch, hback_porch;
> + u32 vsync_len, vfront_porch, vback_porch;
> +
> + hfront_porch = mode->hsync_start - mode->hdisplay;
> + hsync_len = mode->hsync_end - mode->hsync_start;
> + hback_porch = mode->htotal - mode->hsync_end;
> +
> + vfront_porch = mode->vsync_start - mode->vdisplay;
> + vsync_len = mode->vsync_end - mode->vsync_start;
> + vback_porch = mode->vtotal - mode->vsync_end;
> +
> + /* cha, lower 8-bits of hdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> +
> + /* cha, upper 4-bits of hdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> +
> + /* cha, lower 8-bits of vdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> +
> + /* cha, upper 4-bits of vdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> +
> + /*cha, lower sync delay */
> + regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> +
> + /*cha, upper sync delay */
> + regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> +
> + /* cha, lower 8-bits of hsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> +
> + /* cha, upper 2-bits of hsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> +
> + /* cha, lower 8-bits of vsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> +
> + /* cha, upper 2-bits of vsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> +
> + /* cha, hback_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> +
> + /* cha, vback_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> +
> + /* cha, hfront_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> +
> + /* cha, vfront_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> +}
> +
> +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> + unsigned long start, unsigned long diff)
> +{
> + unsigned long next;
> + int i;
> +
> + for (i = min; i <= max; i++) {
> + next = start + diff;
> + if (start <= clock && clock < next)
> + return i;
> +
> + start += diff;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static void sn65dsi_enable(struct drm_bridge *bridge)
> +{
> + struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> + struct drm_display_mode *mode = bridge_to_mode(bridge);
> + int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> + unsigned int lanes = sn->dsi->lanes;
> + unsigned int pixel_clk = mode->clock * 1000;
> + unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> + unsigned int val;
> +
> + /* reset SOFT_RESET bit */
> + regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> +
> + msleep(10);
> +
> + /* reset PLL_EN bit */
> + regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> + msleep(10);
> +
> + /* setup lvds clock */
> + val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> + if (val < 0) {
> + DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> + return;
> + }
> +
> + regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> + SN65DSI_LVDS_CLK_MASK,
> + val << SN65DSI_LVDS_CLK_SHIFT);
> +
> + regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> + SN65DSI_LVDS_CLK_SRC_DSI,
> + SN65DSI_LVDS_CLK_SRC_DSI);
> +
> + /* setup bridge clock divider */
> + val = (dsi_clk / pixel_clk) - 1;
> + regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> + SN65DSI_CLK_DIV_MASK,
> + val << SN65DSI_CLK_DIV_SHIFT);
> +
> + /* configure dsi */
> + regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> + SN65DSI_DSI_LANE_MASK,
> + lanes << SN65DSI_DSI_LANE_SHIFT);
> +
> + /* dsi clock range */
> + val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> + if (val < 0) {
> + DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> + return;
> + }
> +
> + regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> +
> + /* setup lvds channels */
> + regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> + if (bpp == 24)
> + val |= SN65DSI_LVDS_CHA_24BPP;
> + regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
This register should have even how data are packed by dsi. There are two mode
mode 1 and mode 2.
> +
> + /* TODO Channel B required to set up for dual-link LVDS */
> + sn65dsi_setup_channels(sn, mode);
> +
> + /* set SOFT_RESET bit */
> + regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> +
> + msleep(10);
> +
> + /* set PLL_EN bit */
> + regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
> +
> + msleep(10);
> +}
> +
> +static void sn65dsi_disable(struct drm_bridge *bridge)
> +{
> + struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> + /* set PLL_EN bit */
> + regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> + msleep(10);
> +
> + /* set SOFT_RESET bit */
> + regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> +
> + msleep(10);
Can you point me out the documenation where is written
> +}
> +
> +static void sn65dsi_post_disable(struct drm_bridge *bridge)
> +{
> + struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> + gpiod_set_value_cansleep(sn->enable, 1);
> +
> + msleep(10);
> +
> + gpiod_set_value_cansleep(sn->enable, 0);
> +
> + msleep(10);
Again is there any description about the reset time in datasheet. If
so, please point to the section
> +}
> +
> +static void sn65dsi_pre_enable(struct drm_bridge *bridge)
> +{
> + struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> + gpiod_set_value_cansleep(sn->enable, 0);
> +
> + msleep(10);
> +
> + gpiod_set_value_cansleep(sn->enable, 1);
> +
> + msleep(10);
Ditto
> +}
> +
> +static int sn65dsi_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
> +{
> + struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> + struct mipi_dsi_host *host;
> + struct mipi_dsi_device *dsi;
> + const struct mipi_dsi_device_info info = { .type = "sn65dsi",
> + .channel = 0,
> + .node = NULL,
> + };
> + int ret;
> +
> + host = of_find_mipi_dsi_host_by_node(sn->host_node);
> + if (!host) {
> + DRM_DEV_ERROR(sn->dev, "failed to find dsi host\n");
> + return -EPROBE_DEFER;
> + }
> +
> + dsi = mipi_dsi_device_register_full(host, &info);
> + if (IS_ERR(dsi)) {
> + DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
> + return PTR_ERR(sn->dsi);
> + }
> +
> + sn->dsi = dsi;
> + dsi->lanes = sn->dsi_lanes;
> + dsi->format = MIPI_DSI_FMT_RGB888;
> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> +
> + ret = mipi_dsi_attach(dsi);
> + if (ret) {
> + DRM_DEV_ERROR(sn->dev, "failed to attach dsi host\n");
> + goto err_dsi_attach;
> + }
> +
> + return drm_bridge_attach(bridge->encoder, sn->panel_bridge,
> + &sn->bridge, flags);
> +
> +err_dsi_attach:
> + mipi_dsi_device_unregister(dsi);
> + return ret;
> +}
> +
> +static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
> + .attach = sn65dsi_attach,
> + .pre_enable = sn65dsi_pre_enable,
> + .enable = sn65dsi_enable,
> + .disable = sn65dsi_disable,
> + .post_disable = sn65dsi_post_disable,
> +};
> +
> +static int sn65dsi_parse_dt(struct sn65dsi *sn)
> +{
> + struct device *dev = sn->dev;
> + struct device_node *endpoint, *parent;
> + struct property *prop;
> + struct drm_panel *panel;
> + int len = 0;
> + int ret;
> +
> + sn->enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> + if (IS_ERR(sn->enable)) {
> + DRM_DEV_ERROR(dev, "failed to get enable gpio\n");
> + return PTR_ERR(sn->enable);
> + }
> +
> + ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> + if (ret < 0)
> + return ret;
> + if (!panel)
> + return -ENODEV;
> +
> + sn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> + if (IS_ERR(sn->panel_bridge))
> + return PTR_ERR(sn->panel_bridge);
> +
> + /*
> + * To get the data-lanes of dsi, we need to access the port1 of dsi_out
> + * from the port0 of bridge.
> + */
> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> + if (endpoint) {
What is happen if you have no endpoint should not already fail?
> + /* dsi_out node */
> + parent = of_graph_get_remote_port_parent(endpoint);
> + of_node_put(endpoint);
> + if (parent) {
> + /* dsi port 1 */
> + endpoint = of_graph_get_endpoint_by_regs(parent, 1, -1);
> + of_node_put(parent);
> + if (endpoint) {
> + prop = of_find_property(endpoint, "data-lanes", &len);
> + of_node_put(endpoint);
> + if (!prop) {
> + DRM_DEV_ERROR(dev, "failed to find data lane\n");
> + return -EPROBE_DEFER;
> + }
> + }
> + }
> + }
> +
> + sn->dsi_lanes = len / sizeof(u32);
> + if (sn->dsi_lanes < 1 || sn->dsi_lanes > 4)
> + return -EINVAL;
> +
> + sn->host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
> + if (!sn->host_node)
> + return -ENODEV;
> +
> + of_node_put(sn->host_node);
> +
> + return 0;
> +}
> +
> +static int sn65dsi_probe(struct i2c_client *client)
> +{
> + struct sn65dsi *sn;
> + int ret;
> +
> + sn = devm_kzalloc(&client->dev, sizeof(*sn), GFP_KERNEL);
> + if (!sn)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, sn);
> + sn->dev = &client->dev;
> +
> + sn->regmap = devm_regmap_init_i2c(client, &sn65dsi_regmap_config);
> + if (IS_ERR(sn->regmap)) {
> + DRM_DEV_ERROR(&client->dev,
> + "regmap allocation failed (ret = %d)\n", ret);
> + return PTR_ERR(sn->regmap);
> + }
> +
> + ret = sn65dsi_parse_dt(sn);
> + if (ret)
> + return ret;
> +
> + sn->bridge.funcs = &sn65dsi_bridge_funcs;
> + sn->bridge.of_node = client->dev.of_node;
> +
> + drm_bridge_add(&sn->bridge);
> +
> + return 0;
> +}
> +
> +static int sn65dsi_remove(struct i2c_client *client)
> +{
> + struct sn65dsi *sn = i2c_get_clientdata(client);
> +
> + drm_bridge_remove(&sn->bridge);
> +
> + return 0;
> +}
> +
> +static struct i2c_device_id sn65dsi_i2c_id[] = {
> + { "sn65dsi84", 0},
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, sn65dsi_i2c_id);
> +
> +static const struct of_device_id sn65dsi_match_table[] = {
> + {.compatible = "ti,sn65dsi84"},
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sn65dsi_match_table);
> +
> +static struct i2c_driver sn65dsi_driver = {
> + .driver = {
> + .name = "ti-sn65dsi84",
> + .of_match_table = sn65dsi_match_table,
> + },
> + .probe_new = sn65dsi_probe,
> + .remove = sn65dsi_remove,
> + .id_table = sn65dsi_i2c_id,
> +};
> +module_i2c_driver(sn65dsi_driver);
> +
> +MODULE_AUTHOR("Jagan Teki <jagan at amarulasolutions.com>");
> +MODULE_DESCRIPTION("SN65DSI84 DSI to LVDS bridge");
> +MODULE_LICENSE("GPL v2");
> --
> 2.25.1
>
>
--
Michael Nazzareno Trimarchi
Amarula Solutions BV
COO Co-Founder
Cruquiuskade 47 Amsterdam 1018 AM NL
T. +31(0)851119172
M. +39(0)3479132170
[`as] https://www.amarulasolutions.com
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