[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[Jitao Shi]

Add documentation for DT properties supported by
ps8640 DSI-eDP converter.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 .../devicetree/bindings/display/bridge/ps8640.txt  |   43 ++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/ps8640.txt

diff --git a/Documentation/devicetree/bindings/display/bridge/ps8640.txt b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
new file mode 100644
index 0000000..7edc547
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
@@ -0,0 +1,43 @@
+ps8640-bridge bindings
+
+Required properties:
+	- compatible: "parade,ps8640"
+	- reg: first page address of the bridge.
+	- sleep-gpios: OF device-tree gpio specification for PD_ pin.
+	- reset-gpios: OF device-tree gpio specification for reset pin.
+	- mode-sel-gpios: OF device-tree gpio specification for mode-sel pin.
+	- vdd12-supply: OF device-tree regulator specification for 1.2V power.
+	- vdd33-supply: OF device-tree regulator specification for 3.3V power.
+	- ports: The device node can contain video interface port nodes per
+		 the video-interfaces bind[1]. For port at 0,set the reg = <0> as
+		 ps8640 dsi in and port at 1,set the reg = <1> as ps8640 eDP out.
+
+[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
+
+Example:
+	edp-bridge at 18 {
+		compatible = "parade,ps8640";
+		reg = <0x18>;
+		sleep-gpios = <&pio 116 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&pio 115 GPIO_ACTIVE_HIGH>;
+		mode-sel-gpios = <&pio 92 GPIO_ACTIVE_HIGH>;
+		ps8640-1v2-supply = <&ps8640_fixed_1v2>;
+		ps8640-3v3-supply = <&mt6397_vgp2_reg>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			port at 0 {
+				reg = <0>;
+				ps8640_in: endpoint {
+					remote-endpoint = <&dsi0_out>;
+				};
+			};
+			port at 1 {
+				reg = <1>;
+				ps8640_out: endpoint {
+					remote-endpoint = <&panel_in>;
+				};
+			};
+		};
+	};
-- 
1.7.9.5

[RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Jitao Shi]

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 |  479 ++++++++++++++++++++++++++++++++
 3 files changed, 489 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..52616ba
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,479 @@
+/*
+ * 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>
+
+#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_slp_n;
+	struct gpio_desc *gpio_mode_sel_n;
+	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_slp_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_slp_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;
+	u32 temp_reg;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	if (!ps_bridge)
+		return -ENOMEM;
+
+	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;
+
+	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");
+	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, "vdd12-supply");
+	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_slp_n = devm_gpiod_get(&client->dev, "sleep-gpios",
+					       GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_slp_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_slp_n);
+		DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
+		return ret;
+	}
+
+	ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
+	if (ret) {
+		DRM_ERROR("cannot configure gpio_slp_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

[RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[jitao shi]

On Mon, 2015-11-02 at 10:09 +0800, Jitao Shi wrote:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
changes since v1:
        1. remove edid code
        2. remove some wrong comments
        3. tune some gpios name, make it easy understand the meaning
> ---
>  drivers/gpu/drm/bridge/Kconfig         |    9 +
>  drivers/gpu/drm/bridge/Makefile        |    1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c |  479 ++++++++++++++++++++++++++++++++
>  3 files changed, 489 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..52616ba
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,479 @@
> +/*
> + * 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>
> +
> +#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_slp_n;
> +	struct gpio_desc *gpio_mode_sel_n;
> +	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_slp_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_slp_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;
> +	u32 temp_reg;
> +
> +	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +	if (!ps_bridge)
> +		return -ENOMEM;
> +
> +	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;
> +
> +	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");
> +	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, "vdd12-supply");
> +	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_slp_n = devm_gpiod_get(&client->dev, "sleep-gpios",
> +					       GPIOD_OUT_HIGH);
> +	if (IS_ERR(ps_bridge->gpio_slp_n)) {
> +		ret = PTR_ERR(ps_bridge->gpio_slp_n);
> +		DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
> +	if (ret) {
> +		DRM_ERROR("cannot configure gpio_slp_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");

[RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Philipp Zabel]

Hi Jitao,

a few comments below.

Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi:
[...]
> > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)

This could be bool and return true/false.

> > +{
> > +	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);

Can you introduce #defines with descriptive names for those magic
constants and register offsets, and maybe also i2c address offsets?

> > +
> > +		return 0;
> > +	}
> > +
> > +	return -1;

Never return -1 to signal a problem.
If there was an error, use a proper error code.

> > +}
> > +
> > +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);

Missing panel unprepare.

> > +		return;
> > +	}
> > +
> > +	err = regulator_enable(ps_bridge->pwr_3v3_supply);
> > +	if (err < 0) {
> > +		DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);

Missing panel unprepare and vdd12 regulator disable.

> > +		return;
> > +	}
> > +
> > +	gpiod_set_value(ps_bridge->gpio_slp_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;

The return is superfluous.

> > +	}
> > +}
> > +
> > +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;

Shouldn't we still disable the bridge, even if panel disable fails?

> > +	}
> > +
> > +	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_slp_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;

Drop the 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;
> > +	u32 temp_reg;
> > +
> > +	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> > +	if (!ps_bridge)
> > +		return -ENOMEM;
> > +
> > +	in_ep = of_graph_get_next_endpoint(np, NULL);
> > +	if (in_ep) {
> > +		out_ep = of_graph_get_next_endpoint(np, in_ep);

Better use:
	port = of_graph_get_port_by_id(np, 1);
	out_ep = of_get_child_by_name(port, "endpoint");

> > +		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;
> > +
> > +	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");
> > +	if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> > +		dev_err(dev, "cannot get ps_bridge->pwr_3v3_supply\n");

Instead of printing the variable name, just say "vdd3-supply". Also, it
is good practice to print the actual error value.

> > +		return PTR_ERR(ps_bridge->pwr_3v3_supply);
> > +	}
> > +
> > +	ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12-supply");
> > +	if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> > +		dev_err(dev, "cannot get ps_bridge->pwr_1v2_supply\n");

Same as above.

> > +		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);

It would be better to use dev_err instead of DRM_ERROR. The same applies
to the DRM_ERRORs below.

> > +		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_slp_n = devm_gpiod_get(&client->dev, "sleep-gpios",
> > +					       GPIOD_OUT_HIGH);
> > +	if (IS_ERR(ps_bridge->gpio_slp_n)) {
> > +		ret = PTR_ERR(ps_bridge->gpio_slp_n);
> > +		DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
> > +	if (ret) {
> > +		DRM_ERROR("cannot configure gpio_slp_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;

No need for this, the i2c address is already stored in client->addr.

> > +	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");

best regards
Philipp

[RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[jitao shi]

Hi Philipp

I'll fixed those comments on V3.

Thank you very much.

Best Regards.

On Mon, 2015-11-02 at 12:34 +0100, Philipp Zabel wrote:
> Hi Jitao,
> 
> a few comments below.
> 
> Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi:
> [...]
> > > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)
> 
> This could be bool and return true/false.
> 
> > > +{
> > > +	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);
> 
> Can you introduce #defines with descriptive names for those magic
> constants and register offsets, and maybe also i2c address offsets?
> 
> > > +
> > > +		return 0;
> > > +	}
> > > +
> > > +	return -1;
> 
> Never return -1 to signal a problem.
> If there was an error, use a proper error code.
> 
> > > +}
> > > +
> > > +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);
> 
> Missing panel unprepare.
> 
> > > +		return;
> > > +	}
> > > +
> > > +	err = regulator_enable(ps_bridge->pwr_3v3_supply);
> > > +	if (err < 0) {
> > > +		DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);
> 
> Missing panel unprepare and vdd12 regulator disable.
> 
> > > +		return;
> > > +	}
> > > +
> > > +	gpiod_set_value(ps_bridge->gpio_slp_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;
> 
> The return is superfluous.
> 
> > > +	}
> > > +}
> > > +
> > > +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;
> 
> Shouldn't we still disable the bridge, even if panel disable fails?
> 
> > > +	}
> > > +
> > > +	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_slp_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;
> 
> Drop the 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;
> > > +	u32 temp_reg;
> > > +
> > > +	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> > > +	if (!ps_bridge)
> > > +		return -ENOMEM;
> > > +
> > > +	in_ep = of_graph_get_next_endpoint(np, NULL);
> > > +	if (in_ep) {
> > > +		out_ep = of_graph_get_next_endpoint(np, in_ep);
> 
> Better use:
> 	port = of_graph_get_port_by_id(np, 1);
> 	out_ep = of_get_child_by_name(port, "endpoint");
> 
> > > +		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;
> > > +
> > > +	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");
> > > +	if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> > > +		dev_err(dev, "cannot get ps_bridge->pwr_3v3_supply\n");
> 
> Instead of printing the variable name, just say "vdd3-supply". Also, it
> is good practice to print the actual error value.
> 
> > > +		return PTR_ERR(ps_bridge->pwr_3v3_supply);
> > > +	}
> > > +
> > > +	ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12-supply");
> > > +	if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> > > +		dev_err(dev, "cannot get ps_bridge->pwr_1v2_supply\n");
> 
> Same as above.
> 
> > > +		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);
> 
> It would be better to use dev_err instead of DRM_ERROR. The same applies
> to the DRM_ERRORs below.
> 
> > > +		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_slp_n = devm_gpiod_get(&client->dev, "sleep-gpios",
> > > +					       GPIOD_OUT_HIGH);
> > > +	if (IS_ERR(ps_bridge->gpio_slp_n)) {
> > > +		ret = PTR_ERR(ps_bridge->gpio_slp_n);
> > > +		DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
> > > +	if (ret) {
> > > +		DRM_ERROR("cannot configure gpio_slp_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;
> 
> No need for this, the i2c address is already stored in client->addr.
> 
> > > +	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");
> 
> best regards
> Philipp
> 

[RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Philipp Zabel]

Hi Jitao,

some things I missed before.

Am Montag, den 02.11.2015, 10:09 +0800 schrieb Jitao Shi:
[...]
> +static int ps8640_regr(struct i2c_client *client, u16 i2c_addr,
> +		       u8 reg, u8 *value)
> +{
> +	int ret;
> +
> +	client->addr = i2c_addr;

I think i2c_new_dummy should be used to create additional clients for
the secondary addresses, instead of changing the address of the client
with every transfer.

> +	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_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;
> +	u32 temp_reg;
> +
> +	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +	if (!ps_bridge)
> +		return -ENOMEM;
> +
> +	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;
> +
> +	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");

Should be "vdd3", regulator_get will add the "-supply" suffix.

> +	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, "vdd12-supply");

Same here, "vdd12".

> +	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_slp_n = devm_gpiod_get(&client->dev, "sleep-gpios",
> +					       GPIOD_OUT_HIGH);

Should be "sleep", gpiod_get will add the "-gpios" suffix.

> +	if (IS_ERR(ps_bridge->gpio_slp_n)) {
> +		ret = PTR_ERR(ps_bridge->gpio_slp_n);
> +		DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
> +	if (ret) {
> +		DRM_ERROR("cannot configure gpio_slp_n\n");
> +		return ret;
> +	}

This can be removed, the "devm_gpiod_get(..., GPIOD_OUT_HIGH);" already
does the same.

> +
> +	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;
> +	}

Same here, the gpiod_direction_output can be removed.

best regards
Philipp

[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[jitao shi]

On Mon, 2015-11-02 at 10:09 +0800, Jitao Shi wrote:
> Add documentation for DT properties supported by
> ps8640 DSI-eDP converter.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
changes since v1:
        1. changes power-gpios to sleep-gpios.
        2. drop "ps8640-" in properties.
        3. add ports property.
> ---
>  .../devicetree/bindings/display/bridge/ps8640.txt  |   43 ++++++++++++++++++++
>  1 file changed, 43 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/ps8640.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ps8640.txt b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
> new file mode 100644
> index 0000000..7edc547
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
> @@ -0,0 +1,43 @@
> +ps8640-bridge bindings
> +
> +Required properties:
> +	- compatible: "parade,ps8640"
> +	- reg: first page address of the bridge.
> +	- sleep-gpios: OF device-tree gpio specification for PD_ pin.
> +	- reset-gpios: OF device-tree gpio specification for reset pin.
> +	- mode-sel-gpios: OF device-tree gpio specification for mode-sel pin.
> +	- vdd12-supply: OF device-tree regulator specification for 1.2V power.
> +	- vdd33-supply: OF device-tree regulator specification for 3.3V power.
> +	- ports: The device node can contain video interface port nodes per
> +		 the video-interfaces bind[1]. For port at 0,set the reg = <0> as
> +		 ps8640 dsi in and port at 1,set the reg = <1> as ps8640 eDP out.
> +
> +[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
> +
> +Example:
> +	edp-bridge at 18 {
> +		compatible = "parade,ps8640";
> +		reg = <0x18>;
> +		sleep-gpios = <&pio 116 GPIO_ACTIVE_HIGH>;
> +		reset-gpios = <&pio 115 GPIO_ACTIVE_HIGH>;
> +		mode-sel-gpios = <&pio 92 GPIO_ACTIVE_HIGH>;
> +		ps8640-1v2-supply = <&ps8640_fixed_1v2>;
> +		ps8640-3v3-supply = <&mt6397_vgp2_reg>;
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			port at 0 {
> +				reg = <0>;
> +				ps8640_in: endpoint {
> +					remote-endpoint = <&dsi0_out>;
> +				};
> +			};
> +			port at 1 {
> +				reg = <1>;
> +				ps8640_out: endpoint {
> +					remote-endpoint = <&panel_in>;
> +				};
> +			};
> +		};
> +	};

[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[Philipp Zabel]

Hi Jitao,

Am Montag, den 02.11.2015, 11:53 +0800 schrieb jitao shi:
[...]
> > +Example:
> > +	edp-bridge at 18 {
> > +		compatible = "parade,ps8640";
> > +		reg = <0x18>;
> > +		sleep-gpios = <&pio 116 GPIO_ACTIVE_HIGH>;
> > +		reset-gpios = <&pio 115 GPIO_ACTIVE_HIGH>;
> > +		mode-sel-gpios = <&pio 92 GPIO_ACTIVE_HIGH>;
> > +		ps8640-1v2-supply = <&ps8640_fixed_1v2>;

This should be vdd12-supply now.

> > +		ps8640-3v3-supply = <&mt6397_vgp2_reg>;

Should be vdd33-supply now.

regards
Philipp

[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[jitao shi]

On Mon, 2015-11-02 at 12:09 +0100, Philipp Zabel wrote:
> Hi Jitao,
> 
> Am Montag, den 02.11.2015, 11:53 +0800 schrieb jitao shi:
> [...]
> > > +Example:
> > > +	edp-bridge at 18 {
> > > +		compatible = "parade,ps8640";
> > > +		reg = <0x18>;
> > > +		sleep-gpios = <&pio 116 GPIO_ACTIVE_HIGH>;
> > > +		reset-gpios = <&pio 115 GPIO_ACTIVE_HIGH>;
> > > +		mode-sel-gpios = <&pio 92 GPIO_ACTIVE_HIGH>;
> > > +		ps8640-1v2-supply = <&ps8640_fixed_1v2>;
> 
> This should be vdd12-supply now.

Thanks a lot.  I'll fix it on V3.

> 
> > > +		ps8640-3v3-supply = <&mt6397_vgp2_reg>;
> 
> Should be vdd33-supply now.

I'll fix it on V3.

> 
> regards
> Philipp
> 

[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[Philipp Zabel]

Hi Jitao,

Am Montag, den 02.11.2015, 10:09 +0800 schrieb Jitao Shi:
> Add documentation for DT properties supported by
> ps8640 DSI-eDP converter.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  .../devicetree/bindings/display/bridge/ps8640.txt  |   43 ++++++++++++++++++++
>  1 file changed, 43 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/ps8640.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ps8640.txt b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
> new file mode 100644
> index 0000000..7edc547
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
> @@ -0,0 +1,43 @@
> +ps8640-bridge bindings
> +
> +Required properties:
> +	- compatible: "parade,ps8640"
> +	- reg: first page address of the bridge.
> +	- sleep-gpios: OF device-tree gpio specification for PD_ pin.
> +	- reset-gpios: OF device-tree gpio specification for reset pin.
> +	- mode-sel-gpios: OF device-tree gpio specification for mode-sel pin.
> +	- vdd12-supply: OF device-tree regulator specification for 1.2V power.
> +	- vdd33-supply: OF device-tree regulator specification for 3.3V power.
> +	- ports: The device node can contain video interface port nodes per
> +		 the video-interfaces bind[1]. For port at 0,set the reg = <0> as
> +		 ps8640 dsi in and port at 1,set the reg = <1> as ps8640 eDP out.
> +
> +[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
> +
> +Example:
> +	edp-bridge at 18 {
> +		compatible = "parade,ps8640";
> +		reg = <0x18>;
> +		sleep-gpios = <&pio 116 GPIO_ACTIVE_HIGH>;
> +		reset-gpios = <&pio 115 GPIO_ACTIVE_HIGH>;
> +		mode-sel-gpios = <&pio 92 GPIO_ACTIVE_HIGH>;
> +		ps8640-1v2-supply = <&ps8640_fixed_1v2>;
> +		ps8640-3v3-supply = <&mt6397_vgp2_reg>;

These two should be updated to the new regulator property names.

regards
Philipp

[RFC v2 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[Rob Herring]

On Mon, Nov 02, 2015 at 10:09:25AM +0800, Jitao Shi wrote:
> Add documentation for DT properties supported by
> ps8640 DSI-eDP converter.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>

Acked-by: Rob Herring <robh@kernel.org>

> ---
>  .../devicetree/bindings/display/bridge/ps8640.txt  |   43 ++++++++++++++++++++
>  1 file changed, 43 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/ps8640.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/ps8640.txt b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
> new file mode 100644
> index 0000000..7edc547
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/ps8640.txt
> @@ -0,0 +1,43 @@
> +ps8640-bridge bindings
> +
> +Required properties:
> +	- compatible: "parade,ps8640"
> +	- reg: first page address of the bridge.
> +	- sleep-gpios: OF device-tree gpio specification for PD_ pin.
> +	- reset-gpios: OF device-tree gpio specification for reset pin.
> +	- mode-sel-gpios: OF device-tree gpio specification for mode-sel pin.
> +	- vdd12-supply: OF device-tree regulator specification for 1.2V power.
> +	- vdd33-supply: OF device-tree regulator specification for 3.3V power.
> +	- ports: The device node can contain video interface port nodes per
> +		 the video-interfaces bind[1]. For port at 0,set the reg = <0> as
> +		 ps8640 dsi in and port at 1,set the reg = <1> as ps8640 eDP out.
> +
> +[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
> +
> +Example:
> +	edp-bridge at 18 {
> +		compatible = "parade,ps8640";
> +		reg = <0x18>;
> +		sleep-gpios = <&pio 116 GPIO_ACTIVE_HIGH>;
> +		reset-gpios = <&pio 115 GPIO_ACTIVE_HIGH>;
> +		mode-sel-gpios = <&pio 92 GPIO_ACTIVE_HIGH>;
> +		ps8640-1v2-supply = <&ps8640_fixed_1v2>;
> +		ps8640-3v3-supply = <&mt6397_vgp2_reg>;
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			port at 0 {
> +				reg = <0>;
> +				ps8640_in: endpoint {
> +					remote-endpoint = <&dsi0_out>;
> +				};
> +			};
> +			port at 1 {
> +				reg = <1>;
> +				ps8640_out: endpoint {
> +					remote-endpoint = <&panel_in>;
> +				};
> +			};
> +		};
> +	};
> -- 
> 1.7.9.5
>