[PATCH v3 2/2] drm: bridge: Add TI SN65DSI83/84/85 DSI to LVDS bridge

[Jagan Teki <jagan@amarulasolutions.com>]

SN65DSI83/84/85 devices are MIPI DSI to LVDS based bridge
controller IC's from Texas Instruments.

SN65DSI83 - Single Channel DSI to Single-link LVDS bridge
SN65DSI84 - Single Channel DSI to Dual-link LVDS bridge
SN65DSI85 - Dual Channel DSI to Dual-link LVDS bridge

Driver is adding bridge configuration for Channel A, which
is a common configuration across all the bridge variants.

Add bridge driver for it.

Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v3:
- updated macro names to reflect datasheet
- add compatible for 83, 84 variants
- updated comments, kconfig
- fixed few Michael comments
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        |  20 ++
 drivers/gpu/drm/bridge/Makefile       |   1 +
 drivers/gpu/drm/bridge/ti-sn65dsi8x.c | 475 ++++++++++++++++++++++++++
 4 files changed, 502 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi8x.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 4f1084aae50d..2af01632f557 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6017,6 +6017,12 @@ 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@amarulasolutions.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/display/bridge/ti,sn65dsi8x.yaml
+F:	drivers/gpu/drm/bridge/ti-sn65dsi8x.c
+
 DRM DRIVERS FOR V3D
 M:	Eric Anholt <eric@anholt.net>
 S:	Supported
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 49d1565b7f25..8273a66c0eed 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -253,6 +253,26 @@ config DRM_TI_SN65DSI86
 	help
 	  Texas Instruments SN65DSI86 DSI to eDP Bridge driver
 
+config DRM_TI_SN65DSI8X
+	tristate "TI SN65DSI83/84/85 DSI to LVDS bridge"
+	depends on OF
+	select DRM_KMS_HELPER
+	select DRM_MIPI_DSI
+	select DRM_PANEL_BRIDGE
+	select REGMAP_I2C
+	help
+	  SN65DSI83/84/85 devices are MIPI DSI to LVDS based bridge controller
+	  IC's from Texas Instruments.
+
+	  SN65DSI83 - Single Channel DSI to Single-link LVDS bridge
+	  SN65DSI84 - Single Channel DSI to Dual-link LVDS bridge
+	  SN65DSI85 - Dual Channel DSI to Dual-link LVDS bridge
+
+	  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.
+
 config DRM_TI_TPD12S015
 	tristate "TI TPD12S015 HDMI level shifter and ESD protection"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 3eb84b638988..e3d0dad9be30 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
 obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
 obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
 obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
+obj-$(CONFIG_DRM_TI_SN65DSI8X) += ti-sn65dsi8x.o
 obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
 obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
 obj-$(CONFIG_DRM_NWL_MIPI_DSI) += nwl-dsi.o
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi8x.c b/drivers/gpu/drm/bridge/ti-sn65dsi8x.c
new file mode 100644
index 000000000000..9b05b9295cbd
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi8x.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Engicam srl
+ * Copyright (C) 2021 Amarula Solutions(India)
+ * Author: Jagan Teki <jagan@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>
+
+/* 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
+
+/* register bits */
+#define SOFT_RESET			BIT(0)
+#define PLL_EN				BIT(0)
+#define LVDS_CLK_RANGE_MASK		GENMASK(3, 1)
+#define LVDS_CLK_RANGE_SHIFT		1
+#define HS_CLK_SRC			BIT(0)
+#define DSI_CLK_DIV_MASK		GENMASK(7, 3)
+#define DSI_CLK_DIV_SHIFT		3
+#define CHA_DSI_LANES_MASK		GENMASK(4, 3)
+#define CHA_DSI_LANES_SHIFT		3
+#define HS_NEG_POLARITY			BIT(6)
+#define VS_NEG_POLARITY			BIT(5)
+#define LVDS_LINK_CFG			BIT(4)
+#define CHA_24BPP_MODE			BIT(3)
+#define CHA_SYNC_DELAY_LO		0x20
+#define CHA_SYNC_DELAY_HI		0x00
+
+enum sn65dsi_ports {
+	SN65DSI_IN_DSI,
+	SN65DSI_OUT0_LVDS,
+	SN65DSI_OUT1_LVDS,
+};
+
+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;
+};
+
+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_configure_cha(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, CHA_SYNC_DELAY_LO);
+
+	/*cha, upper sync delay */
+	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, CHA_SYNC_DELAY_HI);
+
+	/* 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,
+			   LVDS_CLK_RANGE_MASK, val << LVDS_CLK_RANGE_SHIFT);
+
+	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK, HS_CLK_SRC, HS_CLK_SRC);
+
+	/* setup bridge clock divider */
+	val = (dsi_clk / pixel_clk) - 1;
+	regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
+			   DSI_CLK_DIV_MASK, val << DSI_CLK_DIV_SHIFT);
+
+	/* configure dsi */
+	regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
+			   CHA_DSI_LANES_MASK, lanes << CHA_DSI_LANES_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 modes */
+	regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
+	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+		val |= VS_NEG_POLARITY;
+	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
+		val |= HS_NEG_POLARITY;
+	if (bpp == 24) /* Channel A mode */
+		val |= CHA_24BPP_MODE;
+	regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
+
+	/* TODO Channel B is not configure yet */
+	sn65dsi_configure_cha(sn, mode);
+
+	/* set PLL_EN bit */
+	regmap_write(sn->regmap, SN65DSI_CLK_PLL, PLL_EN);
+
+	msleep(10);
+
+	/* set SOFT_RESET bit */
+	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SOFT_RESET);
+
+	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);
+}
+
+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);
+}
+
+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);
+}
+
+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;
+	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;
+	}
+
+	sn->dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(sn->dsi)) {
+		DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
+		return PTR_ERR(sn->dsi);
+	}
+
+	sn->dsi->lanes = sn->dsi_lanes;
+	sn->dsi->format = MIPI_DSI_FMT_RGB888;
+	sn->dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
+
+	ret = mipi_dsi_attach(sn->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(sn->dsi);
+	return ret;
+}
+
+static void sn65dsi_detach(struct drm_bridge *bridge)
+{
+	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
+
+	mipi_dsi_detach(sn->dsi);
+	mipi_dsi_device_unregister(sn->dsi);
+}
+
+static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
+	.attach		= sn65dsi_attach,
+	.detach		= sn65dsi_detach,
+	.disable	= sn65dsi_disable,
+	.post_disable	= sn65dsi_post_disable,
+	.pre_enable	= sn65dsi_pre_enable,
+	.enable		= sn65dsi_enable,
+};
+
+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, SN65DSI_OUT0_LVDS,
+					  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, SN65DSI_IN_DSI, -1);
+	if (endpoint) {
+		/* 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);
+
+	/* TODO OUT1_LVDS is not parsed yet */
+
+	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[] = {
+	{ "sn65dsi83", 0},
+	{ "sn65dsi84", 0},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, sn65dsi_i2c_id);
+
+static const struct of_device_id sn65dsi_match_table[] = {
+	{.compatible = "ti,sn65dsi83"},
+	{.compatible = "ti,sn65dsi84"},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sn65dsi_match_table);
+
+static struct i2c_driver sn65dsi_driver = {
+	.driver = {
+		.name = "ti-sn65dsi8x",
+		.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@amarulasolutions.com>");
+MODULE_DESCRIPTION("SN65DSI83/84/85 DSI to LVDS bridge");
+MODULE_LICENSE("GPL v2");
-- 
2.25.1