[PATCH v4 2/2] drm: bridge: add support for lontium LT9611UXC bridge

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

Add support for Lontium LT9611UXC HDMI bridge. Lontium LT9611UXC is a
DSI to HDMI bridge which supports two DSI ports and I2S port as an input
and HDMI port as output. Despite name being similar to LT9611, these
devices are different enough to warrant separate driver.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
 drivers/gpu/drm/bridge/Kconfig             |   13 +
 drivers/gpu/drm/bridge/Makefile            |    1 +
 drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 1002 ++++++++++++++++++++
 3 files changed, 1016 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/lontium-lt9611uxc.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index ef91646441b1..e4110d6ca7b3 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -61,6 +61,19 @@ config DRM_LONTIUM_LT9611
 	  HDMI signals
 	  Please say Y if you have such hardware.
 
+config DRM_LONTIUM_LT9611UXC
+	tristate "Lontium LT9611UXC DSI/HDMI bridge"
+	select SND_SOC_HDMI_CODEC if SND_SOC
+	depends on OF
+	select DRM_PANEL_BRIDGE
+	select DRM_KMS_HELPER
+	select REGMAP_I2C
+	help
+	  Driver for Lontium LT9611UXC DSI to HDMI bridge
+	  chip driver that converts dual DSI and I2S to
+	  HDMI signals
+	  Please say Y if you have such hardware.
+
 config DRM_LVDS_CODEC
 	tristate "Transparent LVDS encoders and decoders support"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 2b3aff104e46..86e7acc76f8d 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
 obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
 obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
 obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o
+obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o
 obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
 obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
new file mode 100644
index 000000000000..0c98d27f84ac
--- /dev/null
+++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
@@ -0,0 +1,1002 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2019-2020. Linaro Limited.
+ */
+
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/wait.h>
+
+#include <sound/hdmi-codec.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+#define EDID_BLOCK_SIZE	128
+#define EDID_NUM_BLOCKS	2
+
+struct lt9611uxc {
+	struct device *dev;
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+
+	struct regmap *regmap;
+	/* Protects all accesses to registers by stopping the on-chip MCU */
+	struct mutex ocm_lock;
+
+	struct wait_queue_head wq;
+
+	struct device_node *dsi0_node;
+	struct device_node *dsi1_node;
+	struct mipi_dsi_device *dsi0;
+	struct mipi_dsi_device *dsi1;
+	struct platform_device *audio_pdev;
+
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *enable_gpio;
+
+	struct regulator_bulk_data supplies[2];
+
+	struct i2c_client *client;
+
+	bool hpd_supported;
+	bool edid_read;
+	uint8_t fw_version;
+};
+
+#define LT9611_PAGE_CONTROL	0xff
+
+static const struct regmap_range_cfg lt9611uxc_ranges[] = {
+	{
+		.name = "register_range",
+		.range_min =  0,
+		.range_max = 0xd0ff,
+		.selector_reg = LT9611_PAGE_CONTROL,
+		.selector_mask = 0xff,
+		.selector_shift = 0,
+		.window_start = 0,
+		.window_len = 0x100,
+	},
+};
+
+static const struct regmap_config lt9611uxc_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xffff,
+	.ranges = lt9611uxc_ranges,
+	.num_ranges = ARRAY_SIZE(lt9611uxc_ranges),
+};
+
+struct lt9611uxc_mode {
+	u16 hdisplay;
+	u16 vdisplay;
+	u8 vrefresh;
+};
+
+/*
+ * This chip supports only a fixed set of modes.
+ * Enumerate them here to check whether the mode is supported.
+ */
+static struct lt9611uxc_mode lt9611uxc_modes[] = {
+	{ 1920, 1080, 60 },
+	{ 1920, 1080, 30 },
+	{ 1920, 1080, 25 },
+	{ 1366, 768, 60 },
+	{ 1360, 768, 60 },
+	{ 1280, 1024, 60 },
+	{ 1280, 800, 60 },
+	{ 1280, 720, 60 },
+	{ 1280, 720, 50 },
+	{ 1280, 720, 30 },
+	{ 1152, 864, 60 },
+	{ 1024, 768, 60 },
+	{ 800, 600, 60 },
+	{ 720, 576, 50 },
+	{ 720, 480, 60 },
+	{ 640, 480, 60 },
+};
+
+static struct lt9611uxc *bridge_to_lt9611uxc(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct lt9611uxc, bridge);
+}
+
+static struct lt9611uxc *connector_to_lt9611uxc(struct drm_connector *connector)
+{
+	return container_of(connector, struct lt9611uxc, connector);
+}
+
+static void lt9611uxc_lock(struct lt9611uxc *lt9611uxc)
+{
+	mutex_lock(&lt9611uxc->ocm_lock);
+	regmap_write(lt9611uxc->regmap, 0x80ee, 0x01);
+}
+
+static void lt9611uxc_unlock(struct lt9611uxc *lt9611uxc)
+{
+	regmap_write(lt9611uxc->regmap, 0x80ee, 0x00);
+	msleep(50);
+	mutex_unlock(&lt9611uxc->ocm_lock);
+}
+
+static irqreturn_t lt9611uxc_irq_thread_handler(int irq, void *dev_id)
+{
+	struct lt9611uxc *lt9611uxc = dev_id;
+	unsigned int irq_status = 0;
+	unsigned int hpd_status = 0;
+
+	lt9611uxc_lock(lt9611uxc);
+
+	regmap_read(lt9611uxc->regmap, 0xb022, &irq_status);
+	regmap_read(lt9611uxc->regmap, 0xb023, &hpd_status);
+	if (irq_status)
+		regmap_write(lt9611uxc->regmap, 0xb022, 0);
+
+	lt9611uxc_unlock(lt9611uxc);
+
+	if (irq_status & BIT(0))
+		lt9611uxc->edid_read = !!(hpd_status & BIT(0));
+
+	if (irq_status & BIT(1)) {
+		if (lt9611uxc->connector.dev)
+			drm_kms_helper_hotplug_event(lt9611uxc->connector.dev);
+		else
+			drm_bridge_hpd_notify(&lt9611uxc->bridge, !!(hpd_status & BIT(1)));
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void lt9611uxc_reset(struct lt9611uxc *lt9611uxc)
+{
+	gpiod_set_value_cansleep(lt9611uxc->reset_gpio, 1);
+	msleep(20);
+
+	gpiod_set_value_cansleep(lt9611uxc->reset_gpio, 0);
+	msleep(20);
+
+	gpiod_set_value_cansleep(lt9611uxc->reset_gpio, 1);
+	msleep(300);
+}
+
+static void lt9611uxc_assert_5v(struct lt9611uxc *lt9611uxc)
+{
+	if (!lt9611uxc->enable_gpio)
+		return;
+
+	gpiod_set_value_cansleep(lt9611uxc->enable_gpio, 1);
+	msleep(20);
+}
+
+static int lt9611uxc_regulator_init(struct lt9611uxc *lt9611uxc)
+{
+	int ret;
+
+	lt9611uxc->supplies[0].supply = "vdd";
+	lt9611uxc->supplies[1].supply = "vcc";
+
+	ret = devm_regulator_bulk_get(lt9611uxc->dev, 2, lt9611uxc->supplies);
+	if (ret < 0)
+		return ret;
+
+	return regulator_set_load(lt9611uxc->supplies[0].consumer, 200000);
+}
+
+static int lt9611uxc_regulator_enable(struct lt9611uxc *lt9611uxc)
+{
+	int ret;
+
+	ret = regulator_enable(lt9611uxc->supplies[0].consumer);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(1000, 10000); /* 50000 according to dtsi */
+
+	ret = regulator_enable(lt9611uxc->supplies[1].consumer);
+	if (ret < 0) {
+		regulator_disable(lt9611uxc->supplies[0].consumer);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct lt9611uxc_mode *lt9611uxc_find_mode(const struct drm_display_mode *mode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(lt9611uxc_modes); i++) {
+		if (lt9611uxc_modes[i].hdisplay == mode->hdisplay &&
+		    lt9611uxc_modes[i].vdisplay == mode->vdisplay &&
+		    lt9611uxc_modes[i].vrefresh == drm_mode_vrefresh(mode)) {
+			return &lt9611uxc_modes[i];
+		}
+	}
+
+	return NULL;
+}
+
+static struct mipi_dsi_device *lt9611uxc_attach_dsi(struct lt9611uxc *lt9611uxc,
+						    struct device_node *dsi_node)
+{
+	const struct mipi_dsi_device_info info = { "lt9611uxc", 0, NULL };
+	struct mipi_dsi_device *dsi;
+	struct mipi_dsi_host *host;
+	int ret;
+
+	host = of_find_mipi_dsi_host_by_node(dsi_node);
+	if (!host) {
+		dev_err(lt9611uxc->dev, "failed to find dsi host\n");
+		return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(dsi)) {
+		dev_err(lt9611uxc->dev, "failed to create dsi device\n");
+		return dsi;
+	}
+
+	dsi->lanes = 4;
+	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 = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		dev_err(lt9611uxc->dev, "failed to attach dsi to host\n");
+		mipi_dsi_device_unregister(dsi);
+		return ERR_PTR(ret);
+	}
+
+	return dsi;
+}
+
+static int lt9611uxc_connector_get_modes(struct drm_connector *connector)
+{
+	struct lt9611uxc *lt9611uxc = connector_to_lt9611uxc(connector);
+	unsigned int count;
+	struct edid *edid;
+
+	edid = lt9611uxc->bridge.funcs->get_edid(&lt9611uxc->bridge, connector);
+	drm_connector_update_edid_property(connector, edid);
+	count = drm_add_edid_modes(connector, edid);
+	kfree(edid);
+
+	return count;
+}
+
+static enum drm_connector_status lt9611uxc_connector_detect(struct drm_connector *connector,
+							    bool force)
+{
+	struct lt9611uxc *lt9611uxc = connector_to_lt9611uxc(connector);
+
+	return lt9611uxc->bridge.funcs->detect(&lt9611uxc->bridge);
+}
+
+static enum drm_mode_status lt9611uxc_connector_mode_valid(struct drm_connector *connector,
+							   struct drm_display_mode *mode)
+{
+	struct lt9611uxc_mode *lt9611uxc_mode = lt9611uxc_find_mode(mode);
+
+	return lt9611uxc_mode ? MODE_OK : MODE_BAD;
+}
+
+static const struct drm_connector_helper_funcs lt9611uxc_bridge_connector_helper_funcs = {
+	.get_modes = lt9611uxc_connector_get_modes,
+	.mode_valid = lt9611uxc_connector_mode_valid,
+};
+
+static const struct drm_connector_funcs lt9611uxc_bridge_connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = lt9611uxc_connector_detect,
+	.destroy = drm_connector_cleanup,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int lt9611uxc_connector_init(struct drm_bridge *bridge, struct lt9611uxc *lt9611uxc)
+{
+	int ret;
+
+	if (!bridge->encoder) {
+		DRM_ERROR("Parent encoder object not found");
+		return -ENODEV;
+	}
+
+	drm_connector_helper_add(&lt9611uxc->connector,
+				 &lt9611uxc_bridge_connector_helper_funcs);
+	ret = drm_connector_init(bridge->dev, &lt9611uxc->connector,
+				 &lt9611uxc_bridge_connector_funcs,
+				 DRM_MODE_CONNECTOR_HDMIA);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector with drm\n");
+		return ret;
+	}
+
+	return drm_connector_attach_encoder(&lt9611uxc->connector, bridge->encoder);
+}
+
+static void lt9611uxc_bridge_detach(struct drm_bridge *bridge)
+{
+	struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
+
+	if (lt9611uxc->dsi1) {
+		mipi_dsi_detach(lt9611uxc->dsi1);
+		mipi_dsi_device_unregister(lt9611uxc->dsi1);
+	}
+
+	mipi_dsi_detach(lt9611uxc->dsi0);
+	mipi_dsi_device_unregister(lt9611uxc->dsi0);
+}
+
+static int lt9611uxc_bridge_attach(struct drm_bridge *bridge,
+				   enum drm_bridge_attach_flags flags)
+{
+	struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
+	int ret;
+
+	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+		ret = lt9611uxc_connector_init(bridge, lt9611uxc);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Attach primary DSI */
+	lt9611uxc->dsi0 = lt9611uxc_attach_dsi(lt9611uxc, lt9611uxc->dsi0_node);
+	if (IS_ERR(lt9611uxc->dsi0))
+		return PTR_ERR(lt9611uxc->dsi0);
+
+	/* Attach secondary DSI, if specified */
+	if (lt9611uxc->dsi1_node) {
+		lt9611uxc->dsi1 = lt9611uxc_attach_dsi(lt9611uxc, lt9611uxc->dsi1_node);
+		if (IS_ERR(lt9611uxc->dsi1)) {
+			ret = PTR_ERR(lt9611uxc->dsi1);
+			goto err_unregister_dsi0;
+		}
+	}
+
+	return 0;
+
+err_unregister_dsi0:
+	mipi_dsi_detach(lt9611uxc->dsi0);
+	mipi_dsi_device_unregister(lt9611uxc->dsi0);
+
+	return ret;
+}
+
+static enum drm_mode_status
+lt9611uxc_bridge_mode_valid(struct drm_bridge *bridge,
+			    const struct drm_display_info *info,
+			    const struct drm_display_mode *mode)
+{
+	struct lt9611uxc_mode *lt9611uxc_mode;
+
+	lt9611uxc_mode = lt9611uxc_find_mode(mode);
+
+	return lt9611uxc_mode ? MODE_OK : MODE_BAD;
+}
+
+static void lt9611uxc_video_setup(struct lt9611uxc *lt9611uxc,
+				  const struct drm_display_mode *mode)
+{
+	u32 h_total, hactive, hsync_len, hfront_porch;
+	u32 v_total, vactive, vsync_len, vfront_porch;
+
+	h_total = mode->htotal;
+	v_total = mode->vtotal;
+
+	hactive = mode->hdisplay;
+	hsync_len = mode->hsync_end - mode->hsync_start;
+	hfront_porch = mode->hsync_start - mode->hdisplay;
+
+	vactive = mode->vdisplay;
+	vsync_len = mode->vsync_end - mode->vsync_start;
+	vfront_porch = mode->vsync_start - mode->vdisplay;
+
+	regmap_write(lt9611uxc->regmap, 0xd00d, (u8)(v_total / 256));
+	regmap_write(lt9611uxc->regmap, 0xd00e, (u8)(v_total % 256));
+
+	regmap_write(lt9611uxc->regmap, 0xd00f, (u8)(vactive / 256));
+	regmap_write(lt9611uxc->regmap, 0xd010, (u8)(vactive % 256));
+
+	regmap_write(lt9611uxc->regmap, 0xd011, (u8)(h_total / 256));
+	regmap_write(lt9611uxc->regmap, 0xd012, (u8)(h_total % 256));
+
+	regmap_write(lt9611uxc->regmap, 0xd013, (u8)(hactive / 256));
+	regmap_write(lt9611uxc->regmap, 0xd014, (u8)(hactive % 256));
+
+	regmap_write(lt9611uxc->regmap, 0xd015, (u8)(vsync_len % 256));
+
+	regmap_update_bits(lt9611uxc->regmap, 0xd016, 0xf, (u8)(hsync_len / 256));
+	regmap_write(lt9611uxc->regmap, 0xd017, (u8)(hsync_len % 256));
+
+	regmap_update_bits(lt9611uxc->regmap, 0xd018, 0xf, (u8)(vfront_porch / 256));
+	regmap_write(lt9611uxc->regmap, 0xd019, (u8)(vfront_porch % 256));
+
+	regmap_update_bits(lt9611uxc->regmap, 0xd01a, 0xf, (u8)(hfront_porch / 256));
+	regmap_write(lt9611uxc->regmap, 0xd01b, (u8)(hfront_porch % 256));
+}
+
+static void lt9611uxc_bridge_mode_set(struct drm_bridge *bridge,
+				      const struct drm_display_mode *mode,
+				      const struct drm_display_mode *adj_mode)
+{
+	struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
+
+	lt9611uxc_lock(lt9611uxc);
+	lt9611uxc_video_setup(lt9611uxc, mode);
+	lt9611uxc_unlock(lt9611uxc);
+}
+
+static enum drm_connector_status lt9611uxc_bridge_detect(struct drm_bridge *bridge)
+{
+	struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
+	unsigned int reg_val = 0;
+	int ret;
+	int connected = 1;
+
+	if (lt9611uxc->hpd_supported) {
+		lt9611uxc_lock(lt9611uxc);
+		ret = regmap_read(lt9611uxc->regmap, 0xb023, &reg_val);
+		lt9611uxc_unlock(lt9611uxc);
+
+		if (ret)
+			dev_err(lt9611uxc->dev, "failed to read hpd status: %d\n", ret);
+		else
+			connected  = reg_val & BIT(1);
+	}
+
+	return connected ?  connector_status_connected :
+				connector_status_disconnected;
+}
+
+static int lt9611uxc_wait_for_edid(struct lt9611uxc *lt9611uxc)
+{
+	return wait_event_interruptible_timeout(lt9611uxc->wq, lt9611uxc->edid_read,
+			msecs_to_jiffies(100));
+}
+
+static int lt9611uxc_get_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
+{
+	struct lt9611uxc *lt9611uxc = data;
+	int ret;
+
+	if (len > EDID_BLOCK_SIZE)
+		return -EINVAL;
+
+	if (block >= EDID_NUM_BLOCKS)
+		return -EINVAL;
+
+	lt9611uxc_lock(lt9611uxc);
+
+	regmap_write(lt9611uxc->regmap, 0xb00b, 0x10);
+
+	regmap_write(lt9611uxc->regmap, 0xb00a, block * EDID_BLOCK_SIZE);
+
+	ret = regmap_noinc_read(lt9611uxc->regmap, 0xb0b0, buf, len);
+	if (ret)
+		dev_err(lt9611uxc->dev, "edid read failed: %d\n", ret);
+
+	lt9611uxc_unlock(lt9611uxc);
+
+	return 0;
+};
+
+static struct edid *lt9611uxc_bridge_get_edid(struct drm_bridge *bridge,
+					      struct drm_connector *connector)
+{
+	struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
+	int ret;
+
+	ret = lt9611uxc_wait_for_edid(lt9611uxc);
+	if (ret < 0) {
+		dev_err(lt9611uxc->dev, "wait for EDID failed: %d\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	return drm_do_get_edid(connector, lt9611uxc_get_edid_block, lt9611uxc);
+}
+
+static const struct drm_bridge_funcs lt9611uxc_bridge_funcs = {
+	.attach = lt9611uxc_bridge_attach,
+	.detach = lt9611uxc_bridge_detach,
+	.mode_valid = lt9611uxc_bridge_mode_valid,
+	.mode_set = lt9611uxc_bridge_mode_set,
+	.detect = lt9611uxc_bridge_detect,
+	.get_edid = lt9611uxc_bridge_get_edid,
+};
+
+static int lt9611uxc_parse_dt(struct device *dev,
+			      struct lt9611uxc *lt9611uxc)
+{
+	lt9611uxc->dsi0_node = of_graph_get_remote_node(dev->of_node, 0, -1);
+	if (!lt9611uxc->dsi0_node) {
+		dev_err(lt9611uxc->dev, "failed to get remote node for primary dsi\n");
+		return -ENODEV;
+	}
+
+	lt9611uxc->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);
+
+	return 0;
+}
+
+static int lt9611uxc_gpio_init(struct lt9611uxc *lt9611uxc)
+{
+	struct device *dev = lt9611uxc->dev;
+
+	lt9611uxc->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(lt9611uxc->reset_gpio)) {
+		dev_err(dev, "failed to acquire reset gpio\n");
+		return PTR_ERR(lt9611uxc->reset_gpio);
+	}
+
+	lt9611uxc->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(lt9611uxc->enable_gpio)) {
+		dev_err(dev, "failed to acquire enable gpio\n");
+		return PTR_ERR(lt9611uxc->enable_gpio);
+	}
+
+	return 0;
+}
+
+static int lt9611uxc_read_device_rev(struct lt9611uxc *lt9611uxc)
+{
+	unsigned int rev0, rev1, rev2;
+	int ret;
+
+	lt9611uxc_lock(lt9611uxc);
+
+	ret = regmap_read(lt9611uxc->regmap, 0x8100, &rev0);
+	ret |= regmap_read(lt9611uxc->regmap, 0x8101, &rev1);
+	ret |= regmap_read(lt9611uxc->regmap, 0x8102, &rev2);
+	if (ret)
+		dev_err(lt9611uxc->dev, "failed to read revision: %d\n", ret);
+	else
+		dev_info(lt9611uxc->dev, "LT9611 revision: 0x%02x.%02x.%02x\n", rev0, rev1, rev2);
+
+	lt9611uxc_unlock(lt9611uxc);
+
+	return ret;
+}
+
+static int lt9611uxc_read_version(struct lt9611uxc *lt9611uxc)
+{
+	unsigned int rev;
+	int ret;
+
+	lt9611uxc_lock(lt9611uxc);
+
+	ret = regmap_read(lt9611uxc->regmap, 0xb021, &rev);
+	if (ret)
+		dev_err(lt9611uxc->dev, "failed to read revision: %d\n", ret);
+	else
+		dev_info(lt9611uxc->dev, "LT9611 version: 0x%02x\n", rev);
+
+	lt9611uxc_unlock(lt9611uxc);
+
+	return ret < 0 ? ret : rev;
+}
+
+static int lt9611uxc_hdmi_hw_params(struct device *dev, void *data,
+				    struct hdmi_codec_daifmt *fmt,
+				    struct hdmi_codec_params *hparms)
+{
+	/*
+	 * LT9611UXC will automatically detect rate and sample size, so no need
+	 * to setup anything here.
+	 */
+	return 0;
+}
+
+static void lt9611uxc_audio_shutdown(struct device *dev, void *data)
+{
+}
+
+static int lt9611uxc_hdmi_i2s_get_dai_id(struct snd_soc_component *component,
+					 struct device_node *endpoint)
+{
+	struct of_endpoint of_ep;
+	int ret;
+
+	ret = of_graph_parse_endpoint(endpoint, &of_ep);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * HDMI sound should be located as reg = <2>
+	 * Then, it is sound port 0
+	 */
+	if (of_ep.port == 2)
+		return 0;
+
+	return -EINVAL;
+}
+
+static const struct hdmi_codec_ops lt9611uxc_codec_ops = {
+	.hw_params	= lt9611uxc_hdmi_hw_params,
+	.audio_shutdown = lt9611uxc_audio_shutdown,
+	.get_dai_id	= lt9611uxc_hdmi_i2s_get_dai_id,
+};
+
+static int lt9611uxc_audio_init(struct device *dev, struct lt9611uxc *lt9611uxc)
+{
+	struct hdmi_codec_pdata codec_data = {
+		.ops = &lt9611uxc_codec_ops,
+		.max_i2s_channels = 2,
+		.i2s = 1,
+		.data = lt9611uxc,
+	};
+
+	lt9611uxc->audio_pdev =
+		platform_device_register_data(dev, HDMI_CODEC_DRV_NAME,
+					      PLATFORM_DEVID_AUTO,
+					      &codec_data, sizeof(codec_data));
+
+	return PTR_ERR_OR_ZERO(lt9611uxc->audio_pdev);
+}
+
+static void lt9611uxc_audio_exit(struct lt9611uxc *lt9611uxc)
+{
+	if (lt9611uxc->audio_pdev) {
+		platform_device_unregister(lt9611uxc->audio_pdev);
+		lt9611uxc->audio_pdev = NULL;
+	}
+}
+
+#define LT9611UXC_FW_PAGE_SIZE 32
+static void lt9611uxc_firmware_write_page(struct lt9611uxc *lt9611uxc, u16 addr, const u8 *buf)
+{
+	struct reg_sequence seq_write_prepare[] = {
+		REG_SEQ0(0x805a, 0x04),
+		REG_SEQ0(0x805a, 0x00),
+
+		REG_SEQ0(0x805e, 0xdf),
+		REG_SEQ0(0x805a, 0x20),
+		REG_SEQ0(0x805a, 0x00),
+		REG_SEQ0(0x8058, 0x21),
+	};
+
+	struct reg_sequence seq_write_addr[] = {
+		REG_SEQ0(0x805b, (addr >> 16) & 0xff),
+		REG_SEQ0(0x805c, (addr >> 8) & 0xff),
+		REG_SEQ0(0x805d, addr & 0xff),
+		REG_SEQ0(0x805a, 0x10),
+		REG_SEQ0(0x805a, 0x00),
+	};
+
+	regmap_write(lt9611uxc->regmap, 0x8108, 0xbf);
+	msleep(20);
+	regmap_write(lt9611uxc->regmap, 0x8108, 0xff);
+	msleep(20);
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_write_prepare, ARRAY_SIZE(seq_write_prepare));
+	regmap_noinc_write(lt9611uxc->regmap, 0x8059, buf, LT9611UXC_FW_PAGE_SIZE);
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_write_addr, ARRAY_SIZE(seq_write_addr));
+	msleep(20);
+}
+
+static void lt9611uxc_firmware_read_page(struct lt9611uxc *lt9611uxc, u16 addr, char *buf)
+{
+	struct reg_sequence seq_read_page[] = {
+		REG_SEQ0(0x805a, 0xa0),
+		REG_SEQ0(0x805a, 0x80),
+		REG_SEQ0(0x805b, (addr >> 16) & 0xff),
+		REG_SEQ0(0x805c, (addr >> 8) & 0xff),
+		REG_SEQ0(0x805d, addr & 0xff),
+		REG_SEQ0(0x805a, 0x90),
+		REG_SEQ0(0x805a, 0x80),
+		REG_SEQ0(0x8058, 0x21),
+	};
+
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_read_page, ARRAY_SIZE(seq_read_page));
+	regmap_noinc_read(lt9611uxc->regmap, 0x805f, buf, LT9611UXC_FW_PAGE_SIZE);
+}
+
+static char *lt9611uxc_firmware_read(struct lt9611uxc *lt9611uxc, size_t size)
+{
+	struct reg_sequence seq_read_setup[] = {
+		REG_SEQ0(0x805a, 0x84),
+		REG_SEQ0(0x805a, 0x80),
+	};
+
+	char *readbuf;
+	u16 offset;
+
+	readbuf = kzalloc(ALIGN(size, 32), GFP_KERNEL);
+	if (!readbuf)
+		return NULL;
+
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_read_setup, ARRAY_SIZE(seq_read_setup));
+
+	for (offset = 0;
+	     offset < size;
+	     offset += LT9611UXC_FW_PAGE_SIZE)
+		lt9611uxc_firmware_read_page(lt9611uxc, offset, &readbuf[offset]);
+
+	return readbuf;
+}
+
+static int lt9611uxc_firmware_update(struct lt9611uxc *lt9611uxc)
+{
+	int ret;
+	u16 offset;
+	size_t remain;
+	char *readbuf;
+	const struct firmware *fw;
+
+	struct reg_sequence seq_setup[] = {
+		REG_SEQ0(0x805e, 0xdf),
+		REG_SEQ0(0x8058, 0x00),
+		REG_SEQ0(0x8059, 0x50),
+		REG_SEQ0(0x805a, 0x10),
+		REG_SEQ0(0x805a, 0x00),
+	};
+
+
+	struct reg_sequence seq_block_erase[] = {
+		REG_SEQ0(0x805a, 0x04),
+		REG_SEQ0(0x805a, 0x00),
+		REG_SEQ0(0x805b, 0x00),
+		REG_SEQ0(0x805c, 0x00),
+		REG_SEQ0(0x805d, 0x00),
+		REG_SEQ0(0x805a, 0x01),
+		REG_SEQ0(0x805a, 0x00),
+	};
+
+	ret = request_firmware(&fw, "lt9611uxc_fw.bin", lt9611uxc->dev);
+	if (ret < 0)
+		return ret;
+
+	dev_info(lt9611uxc->dev, "Updating firmware\n");
+	lt9611uxc_lock(lt9611uxc);
+
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_setup, ARRAY_SIZE(seq_setup));
+
+	/*
+	 * Need erase block 2 timess here. Sometimes, block erase can fail.
+	 * This is a workaroud.
+	 */
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_block_erase, ARRAY_SIZE(seq_block_erase));
+	msleep(3000);
+	regmap_multi_reg_write(lt9611uxc->regmap, seq_block_erase, ARRAY_SIZE(seq_block_erase));
+	msleep(3000);
+
+	for (offset = 0, remain = fw->size;
+	     remain >= LT9611UXC_FW_PAGE_SIZE;
+	     offset += LT9611UXC_FW_PAGE_SIZE, remain -= LT9611UXC_FW_PAGE_SIZE)
+		lt9611uxc_firmware_write_page(lt9611uxc, offset, fw->data + offset);
+
+	if (remain > 0) {
+		char buf[LT9611UXC_FW_PAGE_SIZE];
+
+		memset(buf, 0xff, LT9611UXC_FW_PAGE_SIZE);
+		memcpy(buf, fw->data + offset, remain);
+		lt9611uxc_firmware_write_page(lt9611uxc, offset, buf);
+	}
+	msleep(20);
+
+	readbuf = lt9611uxc_firmware_read(lt9611uxc, fw->size);
+	if (!readbuf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (!memcmp(readbuf, fw->data, fw->size)) {
+		dev_err(lt9611uxc->dev, "Firmware update failed\n");
+		print_hex_dump(KERN_ERR, "fw: ", DUMP_PREFIX_OFFSET, 16, 1, readbuf, fw->size, false);
+		ret = -EINVAL;
+	} else {
+		dev_info(lt9611uxc->dev, "Firmware updates successfully\n");
+		ret = 0;
+	}
+	kfree(readbuf);
+
+out:
+	lt9611uxc_unlock(lt9611uxc);
+	lt9611uxc_reset(lt9611uxc);
+	release_firmware(fw);
+
+	return ret;
+}
+
+static ssize_t lt9611uxc_firmware_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct lt9611uxc *lt9611uxc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = lt9611uxc_firmware_update(lt9611uxc);
+	if (ret < 0)
+		return ret;
+	return len;
+}
+
+static ssize_t lt9611uxc_firmware_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct lt9611uxc *lt9611uxc = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%02x\n", lt9611uxc->fw_version);
+}
+
+static DEVICE_ATTR_RW(lt9611uxc_firmware);
+
+static struct attribute *lt9611uxc_attrs[] = {
+	&dev_attr_lt9611uxc_firmware.attr,
+	NULL,
+};
+
+static const struct attribute_group lt9611uxc_attr_group = {
+	.attrs = lt9611uxc_attrs,
+};
+
+static const struct attribute_group *lt9611uxc_attr_groups[] = {
+	&lt9611uxc_attr_group,
+	NULL,
+};
+
+static int lt9611uxc_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
+{
+	struct lt9611uxc *lt9611uxc;
+	struct device *dev = &client->dev;
+	int ret;
+	bool fw_updated = false;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(dev, "device doesn't support I2C\n");
+		return -ENODEV;
+	}
+
+	lt9611uxc = devm_kzalloc(dev, sizeof(*lt9611uxc), GFP_KERNEL);
+	if (!lt9611uxc)
+		return -ENOMEM;
+
+	lt9611uxc->dev = &client->dev;
+	lt9611uxc->client = client;
+	mutex_init(&lt9611uxc->ocm_lock);
+
+	lt9611uxc->regmap = devm_regmap_init_i2c(client, &lt9611uxc_regmap_config);
+	if (IS_ERR(lt9611uxc->regmap)) {
+		dev_err(lt9611uxc->dev, "regmap i2c init failed\n");
+		return PTR_ERR(lt9611uxc->regmap);
+	}
+
+	ret = lt9611uxc_parse_dt(&client->dev, lt9611uxc);
+	if (ret) {
+		dev_err(dev, "failed to parse device tree\n");
+		return ret;
+	}
+
+	ret = lt9611uxc_gpio_init(lt9611uxc);
+	if (ret < 0)
+		goto err_of_put;
+
+	ret = lt9611uxc_regulator_init(lt9611uxc);
+	if (ret < 0)
+		goto err_of_put;
+
+	lt9611uxc_assert_5v(lt9611uxc);
+
+	ret = lt9611uxc_regulator_enable(lt9611uxc);
+	if (ret)
+		goto err_of_put;
+
+	lt9611uxc_reset(lt9611uxc);
+
+	ret = lt9611uxc_read_device_rev(lt9611uxc);
+	if (ret) {
+		dev_err(dev, "failed to read chip rev\n");
+		goto err_disable_regulators;
+	}
+
+retry:
+	ret = lt9611uxc_read_version(lt9611uxc);
+	if (ret < 0) {
+		dev_err(dev, "failed to read FW version\n");
+		goto err_disable_regulators;
+	} else if (ret == 0) {
+		if (!fw_updated) {
+			fw_updated = true;
+			dev_err(dev, "FW version 0, enforcing firmware update\n");
+			ret = lt9611uxc_firmware_update(lt9611uxc);
+			if (ret < 0)
+				goto err_disable_regulators;
+			else
+				goto retry;
+		} else {
+			dev_err(dev, "FW version 0, update failed\n");
+			ret = -EOPNOTSUPP;
+			goto err_disable_regulators;
+		}
+	} else if (ret < 0x40) {
+		dev_info(dev, "FW version 0x%x, HPD not supported\n", ret);
+	} else {
+		lt9611uxc->hpd_supported = true;
+	}
+	lt9611uxc->fw_version = ret;
+
+	init_waitqueue_head(&lt9611uxc->wq);
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					lt9611uxc_irq_thread_handler,
+					IRQF_ONESHOT, "lt9611uxc", lt9611uxc);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		goto err_disable_regulators;
+	}
+
+	i2c_set_clientdata(client, lt9611uxc);
+
+	lt9611uxc->bridge.funcs = &lt9611uxc_bridge_funcs;
+	lt9611uxc->bridge.of_node = client->dev.of_node;
+	lt9611uxc->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID;
+	if (lt9611uxc->hpd_supported)
+		lt9611uxc->bridge.ops |= DRM_BRIDGE_OP_HPD;
+	lt9611uxc->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
+
+	drm_bridge_add(&lt9611uxc->bridge);
+
+	return lt9611uxc_audio_init(dev, lt9611uxc);
+
+err_disable_regulators:
+	regulator_bulk_disable(ARRAY_SIZE(lt9611uxc->supplies), lt9611uxc->supplies);
+
+err_of_put:
+	of_node_put(lt9611uxc->dsi1_node);
+	of_node_put(lt9611uxc->dsi0_node);
+
+	return ret;
+}
+
+static int lt9611uxc_remove(struct i2c_client *client)
+{
+	struct lt9611uxc *lt9611uxc = i2c_get_clientdata(client);
+
+	disable_irq(client->irq);
+	lt9611uxc_audio_exit(lt9611uxc);
+	drm_bridge_remove(&lt9611uxc->bridge);
+
+	mutex_destroy(&lt9611uxc->ocm_lock);
+
+	regulator_bulk_disable(ARRAY_SIZE(lt9611uxc->supplies), lt9611uxc->supplies);
+
+	of_node_put(lt9611uxc->dsi1_node);
+	of_node_put(lt9611uxc->dsi0_node);
+
+	return 0;
+}
+
+static struct i2c_device_id lt9611uxc_id[] = {
+	{ "lontium,lt9611uxc", 0 },
+	{ /* sentinel */ }
+};
+
+static const struct of_device_id lt9611uxc_match_table[] = {
+	{ .compatible = "lontium,lt9611uxc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lt9611uxc_match_table);
+
+static struct i2c_driver lt9611uxc_driver = {
+	.driver = {
+		.name = "lt9611uxc",
+		.of_match_table = lt9611uxc_match_table,
+		.dev_groups = lt9611uxc_attr_groups,
+	},
+	.probe = lt9611uxc_probe,
+	.remove = lt9611uxc_remove,
+	.id_table = lt9611uxc_id,
+};
+module_i2c_driver(lt9611uxc_driver);
+
+MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
-- 
2.28.0