[RFC 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[CK Hu <ck.hu@mediatek.com>]

From: Jitao Shi <jitao.shi@mediatek.com>

This patch adds drm_bridge driver for parade DSI
to eDP bridge chip.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 drivers/gpu/drm/bridge/Kconfig         |    9 +
 drivers/gpu/drm/bridge/Makefile        |    1 +
 drivers/gpu/drm/bridge/parade-ps8640.c |  489 ++++++++++++++++++++++++++++++++
 3 files changed, 499 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/parade-ps8640.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 2de52a5..8ecaeed 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -29,4 +29,13 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_PARADE_PS8640
+	bool "Parade PS8640 MIPI DSI to eDP Converter"
+	select DRM_KMS_HELPER
+	select DRM_PANEL
+	---help---
+	  Choose this option if you have PS8640 for display
+	  The PS8640 is a high-performance and low-power
+	  MIPI DSI to eDP converter
+
 endmenu
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index e2eef1c..da9e4a4 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -3,3 +3,4 @@ ccflags-y := -Iinclude/drm
 obj-$(CONFIG_DRM_DW_HDMI) += dw_hdmi.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
 obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
+obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
new file mode 100644
index 0000000..dc62dd7
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,489 @@
+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_edid.h>
+
+#define PAGE2_GPIO_L	0xa6
+#define PAGE2_GPIO_H	0xa7
+#define PS_GPIO9	BIT(1)
+
+#define PAGE4_REV_L	0xf0
+#define PAGE4_REV_H	0xf1
+#define PAGE4_CHIP_L	0xf2
+#define PAGE4_CHIP_H	0xf3
+
+#define bridge_to_ps8640(e)	container_of(e, struct ps8640, bridge)
+#define connector_to_ps8640(e)	container_of(e, struct ps8640, connector)
+
+struct ps8640 {
+	struct drm_connector connector;
+	struct drm_bridge bridge;
+	struct i2c_client *client;
+	struct ps8640_driver_data *driver_data;
+	struct regulator *pwr_1v2_supply;
+	struct regulator *pwr_3v3_supply;
+	struct drm_panel *panel;
+	struct gpio_desc *gpio_rst_n;
+	struct gpio_desc *gpio_pwr_n;
+	struct gpio_desc *gpio_mode_sel_n;
+	void *edid;
+	u16 base_reg;
+	bool enabled;
+};
+
+static int ps8640_regr(struct i2c_client *client, u16 i2c_addr,
+		       u8 reg, u8 *value)
+{
+	int ret;
+
+	client->addr = i2c_addr;
+
+	ret = i2c_master_send(client, &reg, 1);
+	if (ret <= 0) {
+		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
+		return ret;
+	}
+
+	ret = i2c_master_recv(client, value, 1);
+	if (ret <= 0) {
+		DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ps8640_regw(struct i2c_client *client, u16 i2c_addr,
+		       u8 reg, u8 value)
+{
+	int ret;
+	char buf[2];
+
+	client->addr = i2c_addr;
+
+	buf[0] = reg;
+	buf[1] = value;
+	ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
+	if (ret <= 0) {
+		DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ps8640_check_valid_id(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->client;
+	u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
+	int retry_cnt = 0;
+
+	do {
+		ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
+			    &chip_id_high);
+		if (chip_id_high != 0x30)
+			DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
+	} while ((retry_cnt++ < 2) && (chip_id_high != 0x30));
+
+	ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_L, &rev_id_low);
+	ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_H, &rev_id_high);
+	ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_L,
+		    &chip_id_low);
+
+	if ((rev_id_low == 0x00) && (rev_id_high == 0x0a) &&
+	    (chip_id_low == 0x00) && (chip_id_high == 0x30))
+		return 1;
+
+	return 0;
+}
+
+static void ps8640_show_mcu_fw_version(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->client;
+	u8 major_ver, minor_ver;
+
+	ps8640_regr(client, ps_bridge->base_reg + 5, 0x4, &major_ver);
+	ps8640_regr(client, ps_bridge->base_reg + 5, 0x5, &minor_ver);
+
+	DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", major_ver, minor_ver);
+}
+
+static int ps8640_bdg_enable(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->client;
+
+	if (ps8640_check_valid_id(ps_bridge)) {
+		ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
+		ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x18);
+		ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
+		ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x1c);
+
+		return 0;
+	}
+
+	return -1;
+}
+
+static void ps8640_prepare(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->client;
+	int err, retry_cnt = 0;
+	u8 set_vdo_done;
+
+	if (ps_bridge->enabled)
+		return;
+
+	if (drm_panel_prepare(ps_bridge->panel)) {
+		DRM_ERROR("failed to prepare panel\n");
+		return;
+	}
+
+	err = regulator_enable(ps_bridge->pwr_1v2_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable pwr_1v2_supply: %d\n", err);
+		return;
+	}
+
+	err = regulator_enable(ps_bridge->pwr_3v3_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);
+		return;
+	}
+
+	gpiod_set_value(ps_bridge->gpio_pwr_n, 1);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+	usleep_range(500, 700);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 1);
+
+	do {
+		msleep(50);
+		ps8640_regr(client, ps_bridge->base_reg + 2, PAGE2_GPIO_H,
+			    &set_vdo_done);
+	} while ((retry_cnt++ < 70) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
+
+	ps8640_show_mcu_fw_version(ps_bridge);
+	ps_bridge->enabled = true;
+}
+
+static void ps8640_pre_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+
+	ps8640_prepare(ps_bridge);
+}
+
+static void ps8640_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+
+	ps8640_bdg_enable(ps_bridge);
+
+	if (drm_panel_enable(ps_bridge->panel)) {
+		DRM_ERROR("failed to enable panel\n");
+		return;
+	}
+}
+
+static void ps8640_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+
+	if (!ps_bridge->enabled)
+		return;
+
+	ps_bridge->enabled = false;
+
+	if (drm_panel_disable(ps_bridge->panel)) {
+		DRM_ERROR("failed to disable panel\n");
+		return;
+	}
+
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+	regulator_disable(ps_bridge->pwr_3v3_supply);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+	gpiod_set_value(ps_bridge->gpio_pwr_n, 0);
+}
+
+static void ps8640_post_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+
+	if (drm_panel_unprepare(ps_bridge->panel)) {
+		DRM_ERROR("failed to unprepare panel\n");
+		return;
+	}
+}
+
+static int ps8640_get_modes(struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge = connector_to_ps8640(connector);
+	struct i2c_client *client = ps_bridge->client;
+
+	ps8640_prepare(ps_bridge);
+	ps8640_regw(client, ps_bridge->base_reg + 2, 0xea, 0xd0);
+
+	return drm_panel_get_modes(ps_bridge->panel);
+}
+
+static struct drm_encoder *ps8640_best_encoder(struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge;
+
+	ps_bridge = connector_to_ps8640(connector);
+	return ps_bridge->bridge.encoder;
+}
+
+static const struct drm_connector_helper_funcs
+	ps8640_connector_helper_funcs = {
+	.get_modes = ps8640_get_modes,
+	.best_encoder = ps8640_best_encoder,
+};
+
+static enum drm_connector_status ps8640_detect(struct drm_connector *connector,
+					       bool force)
+{
+	return connector_status_connected;
+}
+
+static void ps8640_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs ps8640_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ps8640_detect,
+	.destroy = ps8640_connector_destroy,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+int ps8640_bridge_attach(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int ret;
+
+	if (!bridge->encoder) {
+		DRM_ERROR("Parent encoder object not found");
+		return -ENODEV;
+	}
+
+	ret = drm_connector_init(bridge->dev, &ps_bridge->connector,
+				 &ps8640_connector_funcs,
+				 DRM_MODE_CONNECTOR_eDP);
+
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector with drm\n");
+		return ret;
+	}
+
+	drm_connector_helper_add(&ps_bridge->connector,
+				 &ps8640_connector_helper_funcs);
+	drm_connector_register(&ps_bridge->connector);
+
+	ps_bridge->connector.dpms = DRM_MODE_DPMS_ON;
+	drm_mode_connector_attach_encoder(&ps_bridge->connector,
+					  bridge->encoder);
+
+	if (ps_bridge->panel)
+		drm_panel_attach(ps_bridge->panel, &ps_bridge->connector);
+
+	return ret;
+}
+
+static bool ps8640_bridge_mode_fixup(struct drm_bridge *bridge,
+				     const struct drm_display_mode *mode,
+				     struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static const struct drm_bridge_funcs ps8640_bridge_funcs = {
+	.attach = ps8640_bridge_attach,
+	.mode_fixup = ps8640_bridge_mode_fixup,
+	.disable = ps8640_disable,
+	.post_disable = ps8640_post_disable,
+	.pre_enable = ps8640_pre_enable,
+	.enable = ps8640_enable,
+};
+
+static int ps8640_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ps8640 *ps_bridge;
+	struct device_node *np = dev->of_node;
+	struct device_node *in_ep, *out_ep;
+	struct device_node *panel_node = NULL;
+	int ret, size;
+	u32 temp_reg;
+	const u8 *edidp;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	if (!ps_bridge)
+		return -ENOMEM;
+
+	/* FIXME - use of_graph_get_port_by_id(np, 1) on newer kernels */
+	in_ep = of_graph_get_next_endpoint(np, NULL);
+	if (in_ep) {
+		out_ep = of_graph_get_next_endpoint(np, in_ep);
+		of_node_put(in_ep);
+		if (out_ep) {
+			panel_node = of_graph_get_remote_port_parent(out_ep);
+			of_node_put(out_ep);
+		}
+	}
+	if (panel_node) {
+		ps_bridge->panel = of_drm_find_panel(panel_node);
+		of_node_put(panel_node);
+		if (!ps_bridge->panel)
+			return -EPROBE_DEFER;
+	}
+
+	ps_bridge->client = client;
+
+	edidp = of_get_property(np, "edid", &size);
+
+	if (edidp)
+		ps_bridge->edid = devm_kmemdup(&client->dev, edidp, size,
+					       GFP_KERNEL);
+
+	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "ps8640-3v3");
+	if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
+		dev_err(dev, "cannot get ps_bridge->pwr_3v3_supply\n");
+		return PTR_ERR(ps_bridge->pwr_3v3_supply);
+	}
+
+	ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "ps8640-1v2");
+	if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
+		dev_err(dev, "cannot get ps_bridge->pwr_1v2_supply\n");
+		return PTR_ERR(ps_bridge->pwr_1v2_supply);
+	}
+
+	ps_bridge->gpio_mode_sel_n = devm_gpiod_get(&client->dev, "mode-sel",
+						    GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_mode_sel_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_mode_sel_n);
+		DRM_ERROR("cannot get gpio_mode_sel_n %d\n", ret);
+		return ret;
+	}
+
+	ret = gpiod_direction_output(ps_bridge->gpio_mode_sel_n, 1);
+	if (ret) {
+		DRM_ERROR("cannot configure gpio_mode_sel_n\n");
+		return ret;
+	}
+
+	ps_bridge->gpio_pwr_n = devm_gpiod_get(&client->dev, "power",
+					       GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_pwr_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_pwr_n);
+		DRM_ERROR("cannot get gpio_pwr_n %d\n", ret);
+		return ret;
+	}
+
+	ret = gpiod_direction_output(ps_bridge->gpio_pwr_n, 1);
+	if (ret) {
+		DRM_ERROR("cannot configure gpio_pwr_n\n");
+		return ret;
+	}
+
+	ps_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
+					       GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_rst_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_rst_n);
+		DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
+		return ret;
+	}
+
+	ret = gpiod_direction_output(ps_bridge->gpio_rst_n, 1);
+	if (ret) {
+		DRM_ERROR("cannot configure gpio_rst_n\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(dev->of_node, "reg", &temp_reg);
+	if (ret) {
+		DRM_ERROR("Can't read base_reg value\n");
+		return ret;
+	}
+	ps_bridge->base_reg = temp_reg;
+
+	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
+	ps_bridge->bridge.of_node = dev->of_node;
+	ret = drm_bridge_add(&ps_bridge->bridge);
+	if (ret) {
+		DRM_ERROR("Failed to add bridge\n");
+		return ret;
+	}
+
+	i2c_set_clientdata(client, ps_bridge);
+
+	return 0;
+}
+
+static int ps8640_remove(struct i2c_client *client)
+{
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&ps_bridge->bridge);
+
+	return 0;
+}
+
+static const struct i2c_device_id ps8640_i2c_table[] = {
+	{"parade,ps8640", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, ps8640_i2c_table);
+
+static const struct of_device_id ps8640_match[] = {
+	{ .compatible = "parade,ps8640" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ps8640_match);
+
+static struct i2c_driver ps8640_driver = {
+	.id_table = ps8640_i2c_table,
+	.probe = ps8640_probe,
+	.remove = ps8640_remove,
+	.driver = {
+		.name = "parade,ps8640",
+		.owner = THIS_MODULE,
+		.of_match_table = ps8640_match,
+	},
+};
+module_i2c_driver(ps8640_driver);
+
+MODULE_AUTHOR("Jitao Shi <jitao.shi@mediatek.com>");
+MODULE_AUTHOR("CK Hu <ck.hu@mediatek.com>");
+MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.9.5