[PATCH v8 1/2] Documentation: bridge: Add documentation for ps8640 DT properties

[PATCH v8 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>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
---
Changes since v7:
 - No change
---
 .../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..a3e0971
--- /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@0,set the reg = <0> as
+		 ps8640 dsi in and port@1,set the reg = <1> as ps8640 eDP out.
+
+[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
+
+Example:
+	edp-bridge@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>;
+		vdd12-supply = <&ps8640_fixed_1v2>;
+		vdd33-supply = <&mt6397_vgp2_reg>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			port@0 {
+				reg = <0>;
+				ps8640_in: endpoint {
+					remote-endpoint = <&dsi0_out>;
+				};
+			};
+			port@1 {
+				reg = <1>;
+				ps8640_out: endpoint {
+					remote-endpoint = <&panel_in>;
+				};
+			};
+		};
+	};
-- 
1.7.9.5

[PATCH v8 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-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Reviewed-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
Changes since v7:
 - No change
---
 .../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..a3e0971
--- /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@0,set the reg = <0> as
+		 ps8640 dsi in and port@1,set the reg = <1> as ps8640 eDP out.
+
+[1]: Documentation/devicetree/bindings/media/video-interfaces.txt
+
+Example:
+	edp-bridge@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>;
+		vdd12-supply = <&ps8640_fixed_1v2>;
+		vdd33-supply = <&mt6397_vgp2_reg>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			port@0 {
+				reg = <0>;
+				ps8640_in: endpoint {
+					remote-endpoint = <&dsi0_out>;
+				};
+			};
+			port@1 {
+				reg = <1>;
+				ps8640_out: endpoint {
+					remote-endpoint = <&panel_in>;
+				};
+			};
+		};
+	};
-- 
1.7.9.5

[PATCH v8 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>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
---
Changes since v7:
 - No change
---
 .../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..a3e0971
--- /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>;
+		vdd12-supply = <&ps8640_fixed_1v2>;
+		vdd33-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

[PATCH v8 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>
---
Changes since v7:
 - Change ps8640_regw to ps8640_regw_bytes and remove devm_kzalloc
 - Fine tune ps8640 power squence
 - Add ps8640_pre_enable and ps8640_post_disable in ps8640_get_modes
 - Remove unnecessary codes and comments

The following patches are needed to support dsi host through none dsi bus:

https://patchwork.kernel.org/patch/7818431/ ("drm/dsi: check for CONFIG_OF when defining of_mipi_dsi_device_add")
https://patchwork.kernel.org/patch/7818471/ ("drm/dsi: Refactor device creation")
https://patchwork.kernel.org/patch/7818501/ ("drm/dsi: Try to match non-DT dsi devices")
https://patchwork.kernel.org/patch/7818531/ ("drm/dsi: Check for used channels")
https://patchwork.kernel.org/patch/7818561/ ("drm/dsi: Add routine to unregister dsi device")
https://patchwork.kernel.org/patch/7818541/ ("drm/dsi: Get DSI host by DT device node")
---
 drivers/gpu/drm/bridge/Kconfig         |   10 +
 drivers/gpu/drm/bridge/Makefile        |    1 +
 drivers/gpu/drm/bridge/parade-ps8640.c | 1084 ++++++++++++++++++++++++++++++++
 3 files changed, 1095 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 27e2022..fe8ad50 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -40,4 +40,14 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_PARADE_PS8640
+	tristate "Parade PS8640 MIPI DSI to eDP Converter"
+	depends on OF && I2C
+	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 f13c33d..fbe38dc 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.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..0230ab5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,1084 @@
+/*
+ * 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/delay.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+#include <drm/drm_panel.h>
+
+#include <drmP.h>
+#include <drm_atomic_helper.h>
+#include <drm_crtc_helper.h>
+#include <drm_crtc.h>
+#include <drm_mipi_dsi.h>
+
+#define PAGE2_SPI_CFG3		0x82
+#define I2C_TO_SPI_RESET	0x20
+#define PAGE2_ROMADD_BYTE1	0x8e
+#define PAGE2_ROMADD_BYTE2	0x8f
+#define PAGE2_SWSPI_WDATA	0x90
+#define PAGE2_SWSPI_RDATA	0x91
+#define PAGE2_SWSPI_LEN		0x92
+#define PAGE2_SWSPI_CTL		0x93
+#define TRIGGER_NO_READBACK	0x05
+#define TRIGGER_READBACK	0x01
+#define PAGE2_SPI_STATUS	0x9e
+#define PAGE2_GPIO_L		0xa6
+#define PAGE2_GPIO_H		0xa7
+#define PS_GPIO9		BIT(1)
+#define PAGE2_IROM_CTRL		0xb0
+#define IROM_ENABLE		0xc0
+#define IROM_DISABLE		0x80
+#define PAGE2_SW_REST		0xbc
+#define PAGE2_ENCTLSPI_WR	0xda
+#define PAGE2_I2C_BYPASS	0xea
+#define I2C_BYPASS_EN		0xd0
+
+#define PAGE3_SET_ADD		0xfe
+#define PAGE3_SET_VAL		0xff
+#define VDO_CTL_ADD		0x13
+#define VDO_DIS			0x18
+#define VDO_EN			0x1c
+
+#define PAGE4_REV_L		0xf0
+#define PAGE4_REV_H		0xf1
+#define PAGE4_CHIP_L		0xf2
+#define PAGE4_CHIP_H		0xf3
+
+/* Firmware */
+#define SPI_MAX_RETRY_CNT	8
+#define PS_FW_NAME		"ps864x_fw.bin"
+
+#define FW_CHIP_ID_OFFSET	0
+#define FW_VERSION_OFFSET	2
+
+#define bridge_to_ps8640(e)	container_of(e, struct ps8640, bridge)
+#define connector_to_ps8640(e)	container_of(e, struct ps8640, connector)
+
+struct ps8640_info {
+	u8 family_id;
+	u8 variant_id;
+	u16 version;
+};
+
+struct ps8640 {
+	struct drm_connector connector;
+	struct drm_bridge bridge;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *page[8];
+	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;
+	bool enabled;
+
+	/* firmware file name */
+	bool in_fw_update;
+	char *fw_file;
+	struct ps8640_info info;
+};
+
+static const u8 enc_ctrl_code[6] = {0xaa, 0x55, 0x50, 0x41, 0x52, 0x44};
+
+static int ps8640_regr(struct i2c_client *client, u8 reg, u8 *data,
+		       u16 data_len)
+{
+	int ret;
+	struct i2c_msg msgs[] = {
+		{
+		 .addr = client->addr,
+		 .flags = 0,
+		 .len = 1,
+		 .buf = &reg,
+		 },
+		{
+		 .addr = client->addr,
+		 .flags = I2C_M_RD,
+		 .len = data_len,
+		 .buf = data,
+		 }
+	};
+
+	ret = i2c_transfer(client->adapter, msgs, 2);
+
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_regw_bytes(struct i2c_client *client, u8 *data,
+			     u16 data_len)
+{
+	int ret;
+	struct i2c_msg msg;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = data_len;
+	msg.buf = data;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_regw_byte(struct i2c_client *client, u8 reg,  u8 data)
+{
+	int ret;
+	struct i2c_msg msg;
+	u8 buf[] = {reg, data};
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = sizeof(buf);
+	msg.buf = buf;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[5];
+	u8 fw_ver[2];
+
+	ps8640_regr(client, 0x4, fw_ver, 2);
+	ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
+
+	DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
+}
+
+static int ps8640_bridge_enable(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[3];
+	int ret;
+	u8 vdo_ctrl_buf[3] = {PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN};
+
+	ret = ps8640_regw_bytes(client, vdo_ctrl_buf, 3);
+	return ret;
+}
+
+static void ps8640_pre_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct i2c_client *client = ps_bridge->page[2];
+	int err, retry_cnt = 0;
+	u8 set_vdo_done;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (ps_bridge->enabled)
+		return;
+
+	err = drm_panel_prepare(ps_bridge->panel);
+	if (err < 0) {
+		DRM_ERROR("failed to prepare panel: %d\n", err);
+		return;
+	}
+
+	gpiod_set_value(ps_bridge->gpio_slp_n, 1);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+
+	err = regulator_enable(ps_bridge->pwr_1v2_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable vdd12-supply: %d\n", err);
+		goto err_panel_unprepare;
+	}
+
+	err = regulator_enable(ps_bridge->pwr_3v3_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable vdd33-supply: %d\n", err);
+		goto err_regulator_1v2_disable;
+	}
+
+	usleep_range(500, 700);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 1);
+
+	/*
+	 * Wait for the ps8640 embed mcu ready
+	 * First wait 200ms and then check the mcu ready flag every 20ms
+	 */
+	msleep(200);
+	do {
+		err = ps8640_regr(client, PAGE2_GPIO_H, &set_vdo_done, 1);
+		if (err < 0) {
+			DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
+			goto err_regulator_1v2_disable;
+		}
+		msleep(20);
+	} while ((retry_cnt++ < 10) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
+
+	if (ps_bridge->info.version == 0)
+		ps8640_get_mcu_fw_version(ps_bridge);
+	/* Switch access edp panel's edid through i2c */
+	ps8640_regw_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
+	ps_bridge->enabled = true;
+
+	return;
+
+err_regulator_1v2_disable:
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+err_panel_unprepare:
+	drm_panel_unprepare(ps_bridge->panel);
+}
+
+static void ps8640_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = ps8640_bridge_enable(ps_bridge);
+	if (err)
+		DRM_ERROR("failed to enable unmutevideo: %d\n", err);
+
+	err = drm_panel_enable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to enable panel: %d\n", err);
+}
+
+static void ps8640_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = drm_panel_disable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to disable panel: %d\n", err);
+}
+
+static void ps8640_post_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (!ps_bridge->enabled)
+		return;
+
+	ps_bridge->enabled = false;
+
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+	gpiod_set_value(ps_bridge->gpio_slp_n, 0);
+	regulator_disable(ps_bridge->pwr_3v3_supply);
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+
+	err = drm_panel_unprepare(ps_bridge->panel);
+	if (err)
+		DRM_ERROR("failed to unprepare panel: %d\n", err);
+}
+
+static int ps8640_get_modes(struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge = connector_to_ps8640(connector);
+	bool power_off;
+	int num_modes = 0;
+
+	power_off = !ps_bridge->enabled;
+	ps8640_pre_enable(&ps_bridge->bridge);
+
+	num_modes = drm_panel_get_modes(ps_bridge->panel);
+
+	if (power_off)
+		ps8640_post_disable(&ps_bridge->bridge);
+
+	return num_modes;
+}
+
+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);
+	struct device *dev = &ps_bridge->page[0]->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *port, *in_ep;
+	struct device_node *dsi_node = NULL;
+	struct mipi_dsi_host *host = ps_bridge->dsi->host;
+	int ret;
+
+	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: %d\n", ret);
+		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);
+
+	/* port@0 is ps8640 dsi input port */
+	port = of_graph_get_port_by_id(np, 0);
+	if (port) {
+		in_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		if (in_ep) {
+			dsi_node = of_graph_get_remote_port_parent(in_ep);
+			of_node_put(in_ep);
+		}
+	}
+	if (dsi_node) {
+		host = of_find_mipi_dsi_host_by_node(dsi_node);
+		of_node_put(dsi_node);
+		if (!host)
+			return -ENODEV;
+	}
+
+	ps_bridge->dsi->host = host;
+	ps_bridge->dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+				     MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	ps_bridge->dsi->format = MIPI_DSI_FMT_RGB888;
+	ps_bridge->dsi->lanes = 4;
+	ret = mipi_dsi_attach(ps_bridge->dsi);
+	if (ret) {
+		drm_panel_detach(ps_bridge->panel);
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct drm_bridge_funcs ps8640_bridge_funcs = {
+	.attach = ps8640_bridge_attach,
+	.disable = ps8640_disable,
+	.post_disable = ps8640_post_disable,
+	.pre_enable = ps8640_pre_enable,
+	.enable = ps8640_enable,
+};
+
+static ssize_t ps8640_fw_file_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", ps_bridge->fw_file);
+}
+
+static int ps8640_update_file_name(struct device *dev, char **file_name,
+				   const char *buf, size_t count)
+{
+	char *new_file_name;
+
+	/* Simple sanity check */
+	if (count > 64) {
+		dev_warn(dev, "File name too long\n");
+		return -EINVAL;
+	}
+
+	new_file_name = devm_kmalloc(dev, count + 1, GFP_KERNEL);
+	if (!new_file_name)
+		return -ENOMEM;
+
+	memcpy(new_file_name, buf, count + 1);
+
+	/* Echo into the sysfs entry may append newline at the end of buf */
+	if (new_file_name[count - 1] == '\n')
+		count--;
+
+	new_file_name[count] = '\0';
+
+	if (*file_name)
+		devm_kfree(dev, *file_name);
+
+	*file_name = new_file_name;
+
+	return 0;
+}
+
+/* Firmware Version is returned as Major.Minor.Build */
+static ssize_t ps8640_fw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
+			 info->version & 0xff);
+}
+
+/* Hardware Version is returned as FamilyID.VariantID */
+static ssize_t ps8640_hw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
+			 info->variant_id);
+}
+
+static int ps8640_spi_send_cmd(struct ps8640 *ps_bridge, u8 *cmd, u8 cmd_len)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 i;
+	int ret;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	if (ret)
+		goto err;
+
+	/* write command in write port */
+	for (i = 0; i < cmd_len; i++) {
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
+		if (ret)
+			goto err;
+	}
+	/* command length */
+	ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, cmd_len - 1);
+	if (ret)
+		goto err;
+	/* trigger read */
+	ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL, TRIGGER_NO_READBACK);
+	if (ret)
+		goto err;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&client->dev, "send command err: %d\n", ret);
+	return ret;
+}
+
+static int ps8640_wait_spi_ready(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 spi_rdy_st, retry_cnt = 0;
+
+	do {
+		ps8640_regr(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
+		msleep(20);
+		if ((retry_cnt == SPI_MAX_RETRY_CNT) &&
+		    ((spi_rdy_st & 0x0c) != 0x0c)) {
+			dev_err(&client->dev, "wait spi ready timeout\n");
+			return -EBUSY;
+		}
+	} while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
+		 (spi_rdy_st & 0x0c) == 0x0c);
+
+	return 0;
+}
+
+static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 spi_status, retry_cnt = 0;
+	int ret;
+
+	do {
+		/* 0x05 RDSR; Read-Status-Register */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, 0x05);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* command length */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, 0x00);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* trigger read */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL,
+				       TRIGGER_READBACK);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* delay for cmd send */
+		usleep_range(100, 300);
+		/* wait for SPI ROM until not busy */
+		ret = ps8640_regr(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
+		if (ret)
+			goto err_send_cmd_exit;
+	} while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
+		 (spi_status & 0x0c) == 0x0c);
+
+	if ((retry_cnt > SPI_MAX_RETRY_CNT) && (spi_status & 0x0c) != 0x0c) {
+		ret = -EBUSY;
+		dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
+		goto err_timeout;
+	}
+
+	return 0;
+
+err_send_cmd_exit:
+	dev_err(&client->dev, "send command err: %d\n", ret);
+
+err_timeout:
+	return ret;
+}
+
+static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	int ret;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_wait_spi_ready(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_wait_spi_nobusy(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+	if (ret)
+		goto exit;
+
+exit:
+	if (ret)
+		dev_err(&client->dev, "wait ps8640 rom idle fail: %d\n", ret);
+
+	return ret;
+}
+
+static int ps8640_spi_dl_mode(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	int ret;
+
+	/* switch ps8640 mode to spi dl mode */
+	gpiod_set_value(ps_bridge->gpio_mode_sel_n, 0);
+
+	/* reset spi interface */
+	ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0xc0);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0x40);
+	if (ret)
+		goto exit;
+
+exit:
+	if (ret)
+		dev_err(&client->dev, "fail reset spi interface: %d\n", ret);
+
+	return ret;
+}
+
+static int ps8640_rom_prepare(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	struct device *dev = &client->dev;
+	u8 i, cmd[2];
+	int ret;
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "failed enable-write-status-register: %d\n", ret);
+		return ret;
+	}
+
+	/* disable all protection */
+	cmd[0] = 0x01;
+	cmd[1] = 0x00;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 2);
+	if (ret) {
+		dev_err(dev, "fail disable all protection: %d\n", ret);
+		return ret;
+	}
+
+	/* wait for SPI module ready */
+	ret = ps8640_wait_rom_idle(ps_bridge);
+	if (ret) {
+		dev_err(dev, "fail wait rom idle: %d\n", ret);
+		return ret;
+	}
+
+	ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	for (i = 0; i < 6; i++)
+		ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
+	ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "fail enable-write-status-register: %d\n", ret);
+		return ret;
+	}
+
+	/* chip erase command */
+	cmd[0] = 0xc7;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "fail disable all protection: %d\n", ret);
+		return ret;
+	}
+
+	ret = ps8640_wait_rom_idle(ps_bridge);
+	if (ret) {
+		dev_err(dev, "fail wait rom idle: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
+				    const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct ps8640_info *info = &ps_bridge->info;
+	u16 fw_chip_id, fw_version_id;
+
+	/*
+	 * Get the chip_id from the firmware. Make sure that it is the
+	 * right controller to do the firmware and config update.
+	 */
+	fw_chip_id = get_unaligned_le16(fw->data + FW_CHIP_ID_OFFSET);
+
+	if (fw_chip_id != 0x8640) {
+		dev_err(&client->dev,
+			"chip id mismatch: fw 0x%x vs. chip 0x8640\n",
+			fw_chip_id);
+		return -ENODEV;
+	}
+
+	fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
+
+	if (fw_chip_id != info->version) {
+		dev_err(&client->dev,
+			"fw version mismatch: fw %d.%d vs. chip %d.%d\n",
+			fw_version_id >> 8, fw_version_id & 0xff,
+			info->version >> 8, info->version & 0xff);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int ps8640_write_rom(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct device *dev = &client->dev;
+	struct i2c_client *client2 = ps_bridge->page[2];
+	struct i2c_client *client7 = ps_bridge->page[7];
+	unsigned int pos = 0;
+	u8 buf[257], rom_page_id_buf[3];
+	int ret;
+	u16 cpy_len;
+
+	ps8640_regw_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
+	msleep(100);
+	ps8640_regw_byte(client2, PAGE2_SPI_CFG3, 0x00);
+
+	while (pos < fw->size) {
+		rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
+		rom_page_id_buf[1] = (pos >> 8) & 0xff;
+		rom_page_id_buf[2] = (pos >> 16) & 0xff;
+		ret = ps8640_regw_bytes(client2, rom_page_id_buf, 3);
+		if (ret)
+			goto error;
+		cpy_len = fw->size >= 256 + pos ? 256 : fw->size - pos;
+		buf[0] = 0;
+		memcpy(buf + 1, fw->data + pos, cpy_len);
+		ret = ps8640_regw_bytes(client7, buf, cpy_len + 1);
+		if (ret)
+			goto error;
+
+		pos += cpy_len;
+
+		dev_dbg(dev, "fw update completed %u / %zu bytes\n", pos,
+			fw->size);
+	}
+	return 0;
+
+error:
+	dev_err(dev, "failed write extenal flash, %d\n", ret);
+	return ret;
+}
+
+static int ps8640_spi_normal_mode(struct ps8640 *ps_bridge)
+{
+	u8 cmd[2];
+	struct i2c_client *client = ps_bridge->page[2];
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+
+	/* protect BPL/BP0/BP1 */
+	cmd[0] = 0x01;
+	cmd[1] = 0x8c;
+	ps8640_spi_send_cmd(ps_bridge, cmd, 2);
+
+	/* wait for SPI rom ready */
+	ps8640_wait_rom_idle(ps_bridge);
+
+	/* disable PS8640 mapping function */
+	ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
+
+	gpiod_set_value(ps_bridge->gpio_mode_sel_n, 1);
+	return 0;
+}
+
+static int ps8640_enter_bl(struct ps8640 *ps_bridge)
+{
+	int ret;
+
+	ret = ps8640_spi_dl_mode(ps_bridge);
+	if (ret)
+		return ret;
+
+	ps_bridge->in_fw_update = true;
+	return 0;
+}
+
+static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	ps_bridge->in_fw_update = false;
+	ps8640_spi_normal_mode(ps_bridge);
+}
+
+static int ps8640_load_fw(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct device *dev = &client->dev;
+	int ret;
+	bool ps8640_status_backup = ps_bridge->enabled;
+
+	if (!ps_bridge->in_fw_update) {
+		if (!ps8640_status_backup)
+			ps8640_pre_enable(&ps_bridge->bridge);
+
+		ret = ps8640_enter_bl(ps_bridge);
+		if (ret)
+			goto exit;
+	}
+
+	ret = ps8640_validate_firmware(ps_bridge, fw);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_rom_prepare(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_write_rom(ps_bridge, fw);
+
+exit:
+	if (ret)
+		dev_err(dev, "Failed to load firmware, %d\n", ret);
+
+	ps8640_exit_bl(ps_bridge, fw);
+	if (!ps8640_status_backup)
+		ps8640_post_disable(&ps_bridge->bridge);
+	return ret;
+}
+
+static ssize_t ps8640_update_fw_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	const struct firmware *fw;
+	int error;
+
+	error = request_firmware(&fw, ps_bridge->fw_file, dev);
+	if (error) {
+		dev_err(dev, "Unable to open firmware %s: %d\n",
+			ps_bridge->fw_file, error);
+		return error;
+	}
+
+	error = ps8640_load_fw(ps_bridge, fw);
+	if (error)
+		dev_err(dev, "The firmware update failed(%d)\n", error);
+	else
+		dev_info(dev, "The firmware update succeeded\n");
+
+	release_firmware(fw);
+	return error ? error : count;
+}
+
+static DEVICE_ATTR(fw_file, S_IRUGO, ps8640_fw_file_show, NULL);
+static DEVICE_ATTR(fw_version, S_IRUGO, ps8640_fw_version_show, NULL);
+static DEVICE_ATTR(hw_version, S_IRUGO, ps8640_hw_version_show, NULL);
+static DEVICE_ATTR(update_fw, S_IWUSR, NULL, ps8640_update_fw_store);
+
+static struct attribute *ps8640_attrs[] = {
+	&dev_attr_fw_file.attr,
+	&dev_attr_fw_version.attr,
+	&dev_attr_hw_version.attr,
+	&dev_attr_update_fw.attr,
+	NULL
+};
+
+static const struct attribute_group ps8640_attr_group = {
+	.attrs = ps8640_attrs,
+};
+
+static void ps8640_remove_sysfs_group(void *data)
+{
+	struct ps8640 *ps_bridge = data;
+
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+}
+
+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 *port, *out_ep;
+	struct device_node *panel_node = NULL;
+	int i, ret;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
+				      GFP_KERNEL);
+	if (!ps_bridge) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	/* port@1 is ps8640 output port */
+	port = of_graph_get_port_by_id(np, 1);
+	if (port) {
+		out_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		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) {
+			ret = -EPROBE_DEFER;
+			goto exit;
+		}
+	}
+
+	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
+	if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
+		ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
+		dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");
+	if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
+		ret = PTR_ERR(ps_bridge->pwr_1v2_supply);
+		dev_err(dev, "cannot get vdd12 supply: %d\n", ret);
+		goto exit;
+	}
+
+	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);
+		dev_err(dev, "cannot get gpio_mode_sel_n %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->gpio_slp_n = devm_gpiod_get(&client->dev, "sleep",
+					       GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_slp_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_slp_n);
+		dev_err(dev, "cannot get gpio_slp_n: %d\n", ret);
+		goto exit;
+	}
+
+	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);
+		dev_err(dev, "cannot get gpio_rst_n: %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
+	ps_bridge->bridge.of_node = dev->of_node;
+	ret = drm_bridge_add(&ps_bridge->bridge);
+	if (ret) {
+		dev_err(dev, "Failed to add bridge: %d\n", ret);
+		goto exit;
+	}
+
+	ret = ps8640_update_file_name(&client->dev, &ps_bridge->fw_file,
+				      PS_FW_NAME, strlen(PS_FW_NAME));
+	if (ret) {
+		dev_err(dev, "failed to update file name: %d\n", ret);
+		goto exit_drm_bridge_remove;
+	}
+
+	ps_bridge->page[0] = client;
+
+	/*
+	 * ps8640 uses multiple addresses, use dummy devices for them
+	 * page[0]: for DP control
+	 * page[1]: for VIDEO Bridge
+	 * page[2]: for control top
+	 * page[3]: for DSI Link Control1
+	 * page[4]: for MIPI Phy
+	 * page[5]: for VPLL
+	 * page[6]: for DSI Link Control2
+	 * page[7]: for spi rom mapping
+	 */
+	for (i = 1; i < 8; i++) {
+		ps_bridge->page[i] = i2c_new_dummy(client->adapter,
+						   client->addr + i);
+		if (!ps_bridge->page[i]) {
+			dev_err(dev, "failed i2c dummy device, address%02x\n",
+				client->addr + i);
+			ret = -EBUSY;
+			goto exit_dummy;
+		}
+	}
+	i2c_set_clientdata(client, ps_bridge);
+
+	ret = sysfs_create_group(&client->dev.kobj, &ps8640_attr_group);
+	if (ret) {
+		dev_err(dev, "failed to create sysfs entries: %d\n", ret);
+		goto exit_dummy;
+	}
+
+	ret = devm_add_action(dev, ps8640_remove_sysfs_group, ps_bridge);
+	if (ret) {
+		dev_err(dev, "failed to add sysfs cleanup action: %d\n", ret);
+		goto exit_remove_sysfs;
+	}
+	return 0;
+
+exit_remove_sysfs:
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+exit_dummy:
+	for (i = 1; i < 8; i++)
+		if (ps_bridge->page[i])
+			i2c_unregister_device(ps_bridge->page[i]);
+exit_drm_bridge_remove:
+	drm_bridge_remove(&ps_bridge->bridge);
+exit:
+	return ret;
+}
+
+static int ps8640_remove(struct i2c_client *client)
+{
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 1; i < 8; i++)
+		i2c_unregister_device(ps_bridge->page[i]);
+
+	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",
+		.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

[PATCH v8 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-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
Changes since v7:
 - Change ps8640_regw to ps8640_regw_bytes and remove devm_kzalloc
 - Fine tune ps8640 power squence
 - Add ps8640_pre_enable and ps8640_post_disable in ps8640_get_modes
 - Remove unnecessary codes and comments

The following patches are needed to support dsi host through none dsi bus:

https://patchwork.kernel.org/patch/7818431/ ("drm/dsi: check for CONFIG_OF when defining of_mipi_dsi_device_add")
https://patchwork.kernel.org/patch/7818471/ ("drm/dsi: Refactor device creation")
https://patchwork.kernel.org/patch/7818501/ ("drm/dsi: Try to match non-DT dsi devices")
https://patchwork.kernel.org/patch/7818531/ ("drm/dsi: Check for used channels")
https://patchwork.kernel.org/patch/7818561/ ("drm/dsi: Add routine to unregister dsi device")
https://patchwork.kernel.org/patch/7818541/ ("drm/dsi: Get DSI host by DT device node")
---
 drivers/gpu/drm/bridge/Kconfig         |   10 +
 drivers/gpu/drm/bridge/Makefile        |    1 +
 drivers/gpu/drm/bridge/parade-ps8640.c | 1084 ++++++++++++++++++++++++++++++++
 3 files changed, 1095 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 27e2022..fe8ad50 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -40,4 +40,14 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_PARADE_PS8640
+	tristate "Parade PS8640 MIPI DSI to eDP Converter"
+	depends on OF && I2C
+	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 f13c33d..fbe38dc 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.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..0230ab5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,1084 @@
+/*
+ * 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/delay.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+#include <drm/drm_panel.h>
+
+#include <drmP.h>
+#include <drm_atomic_helper.h>
+#include <drm_crtc_helper.h>
+#include <drm_crtc.h>
+#include <drm_mipi_dsi.h>
+
+#define PAGE2_SPI_CFG3		0x82
+#define I2C_TO_SPI_RESET	0x20
+#define PAGE2_ROMADD_BYTE1	0x8e
+#define PAGE2_ROMADD_BYTE2	0x8f
+#define PAGE2_SWSPI_WDATA	0x90
+#define PAGE2_SWSPI_RDATA	0x91
+#define PAGE2_SWSPI_LEN		0x92
+#define PAGE2_SWSPI_CTL		0x93
+#define TRIGGER_NO_READBACK	0x05
+#define TRIGGER_READBACK	0x01
+#define PAGE2_SPI_STATUS	0x9e
+#define PAGE2_GPIO_L		0xa6
+#define PAGE2_GPIO_H		0xa7
+#define PS_GPIO9		BIT(1)
+#define PAGE2_IROM_CTRL		0xb0
+#define IROM_ENABLE		0xc0
+#define IROM_DISABLE		0x80
+#define PAGE2_SW_REST		0xbc
+#define PAGE2_ENCTLSPI_WR	0xda
+#define PAGE2_I2C_BYPASS	0xea
+#define I2C_BYPASS_EN		0xd0
+
+#define PAGE3_SET_ADD		0xfe
+#define PAGE3_SET_VAL		0xff
+#define VDO_CTL_ADD		0x13
+#define VDO_DIS			0x18
+#define VDO_EN			0x1c
+
+#define PAGE4_REV_L		0xf0
+#define PAGE4_REV_H		0xf1
+#define PAGE4_CHIP_L		0xf2
+#define PAGE4_CHIP_H		0xf3
+
+/* Firmware */
+#define SPI_MAX_RETRY_CNT	8
+#define PS_FW_NAME		"ps864x_fw.bin"
+
+#define FW_CHIP_ID_OFFSET	0
+#define FW_VERSION_OFFSET	2
+
+#define bridge_to_ps8640(e)	container_of(e, struct ps8640, bridge)
+#define connector_to_ps8640(e)	container_of(e, struct ps8640, connector)
+
+struct ps8640_info {
+	u8 family_id;
+	u8 variant_id;
+	u16 version;
+};
+
+struct ps8640 {
+	struct drm_connector connector;
+	struct drm_bridge bridge;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *page[8];
+	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;
+	bool enabled;
+
+	/* firmware file name */
+	bool in_fw_update;
+	char *fw_file;
+	struct ps8640_info info;
+};
+
+static const u8 enc_ctrl_code[6] = {0xaa, 0x55, 0x50, 0x41, 0x52, 0x44};
+
+static int ps8640_regr(struct i2c_client *client, u8 reg, u8 *data,
+		       u16 data_len)
+{
+	int ret;
+	struct i2c_msg msgs[] = {
+		{
+		 .addr = client->addr,
+		 .flags = 0,
+		 .len = 1,
+		 .buf = &reg,
+		 },
+		{
+		 .addr = client->addr,
+		 .flags = I2C_M_RD,
+		 .len = data_len,
+		 .buf = data,
+		 }
+	};
+
+	ret = i2c_transfer(client->adapter, msgs, 2);
+
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_regw_bytes(struct i2c_client *client, u8 *data,
+			     u16 data_len)
+{
+	int ret;
+	struct i2c_msg msg;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = data_len;
+	msg.buf = data;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_regw_byte(struct i2c_client *client, u8 reg,  u8 data)
+{
+	int ret;
+	struct i2c_msg msg;
+	u8 buf[] = {reg, data};
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = sizeof(buf);
+	msg.buf = buf;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[5];
+	u8 fw_ver[2];
+
+	ps8640_regr(client, 0x4, fw_ver, 2);
+	ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
+
+	DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
+}
+
+static int ps8640_bridge_enable(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[3];
+	int ret;
+	u8 vdo_ctrl_buf[3] = {PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN};
+
+	ret = ps8640_regw_bytes(client, vdo_ctrl_buf, 3);
+	return ret;
+}
+
+static void ps8640_pre_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct i2c_client *client = ps_bridge->page[2];
+	int err, retry_cnt = 0;
+	u8 set_vdo_done;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (ps_bridge->enabled)
+		return;
+
+	err = drm_panel_prepare(ps_bridge->panel);
+	if (err < 0) {
+		DRM_ERROR("failed to prepare panel: %d\n", err);
+		return;
+	}
+
+	gpiod_set_value(ps_bridge->gpio_slp_n, 1);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+
+	err = regulator_enable(ps_bridge->pwr_1v2_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable vdd12-supply: %d\n", err);
+		goto err_panel_unprepare;
+	}
+
+	err = regulator_enable(ps_bridge->pwr_3v3_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable vdd33-supply: %d\n", err);
+		goto err_regulator_1v2_disable;
+	}
+
+	usleep_range(500, 700);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 1);
+
+	/*
+	 * Wait for the ps8640 embed mcu ready
+	 * First wait 200ms and then check the mcu ready flag every 20ms
+	 */
+	msleep(200);
+	do {
+		err = ps8640_regr(client, PAGE2_GPIO_H, &set_vdo_done, 1);
+		if (err < 0) {
+			DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
+			goto err_regulator_1v2_disable;
+		}
+		msleep(20);
+	} while ((retry_cnt++ < 10) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
+
+	if (ps_bridge->info.version == 0)
+		ps8640_get_mcu_fw_version(ps_bridge);
+	/* Switch access edp panel's edid through i2c */
+	ps8640_regw_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
+	ps_bridge->enabled = true;
+
+	return;
+
+err_regulator_1v2_disable:
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+err_panel_unprepare:
+	drm_panel_unprepare(ps_bridge->panel);
+}
+
+static void ps8640_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = ps8640_bridge_enable(ps_bridge);
+	if (err)
+		DRM_ERROR("failed to enable unmutevideo: %d\n", err);
+
+	err = drm_panel_enable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to enable panel: %d\n", err);
+}
+
+static void ps8640_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = drm_panel_disable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to disable panel: %d\n", err);
+}
+
+static void ps8640_post_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (!ps_bridge->enabled)
+		return;
+
+	ps_bridge->enabled = false;
+
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+	gpiod_set_value(ps_bridge->gpio_slp_n, 0);
+	regulator_disable(ps_bridge->pwr_3v3_supply);
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+
+	err = drm_panel_unprepare(ps_bridge->panel);
+	if (err)
+		DRM_ERROR("failed to unprepare panel: %d\n", err);
+}
+
+static int ps8640_get_modes(struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge = connector_to_ps8640(connector);
+	bool power_off;
+	int num_modes = 0;
+
+	power_off = !ps_bridge->enabled;
+	ps8640_pre_enable(&ps_bridge->bridge);
+
+	num_modes = drm_panel_get_modes(ps_bridge->panel);
+
+	if (power_off)
+		ps8640_post_disable(&ps_bridge->bridge);
+
+	return num_modes;
+}
+
+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);
+	struct device *dev = &ps_bridge->page[0]->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *port, *in_ep;
+	struct device_node *dsi_node = NULL;
+	struct mipi_dsi_host *host = ps_bridge->dsi->host;
+	int ret;
+
+	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: %d\n", ret);
+		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);
+
+	/* port@0 is ps8640 dsi input port */
+	port = of_graph_get_port_by_id(np, 0);
+	if (port) {
+		in_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		if (in_ep) {
+			dsi_node = of_graph_get_remote_port_parent(in_ep);
+			of_node_put(in_ep);
+		}
+	}
+	if (dsi_node) {
+		host = of_find_mipi_dsi_host_by_node(dsi_node);
+		of_node_put(dsi_node);
+		if (!host)
+			return -ENODEV;
+	}
+
+	ps_bridge->dsi->host = host;
+	ps_bridge->dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+				     MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	ps_bridge->dsi->format = MIPI_DSI_FMT_RGB888;
+	ps_bridge->dsi->lanes = 4;
+	ret = mipi_dsi_attach(ps_bridge->dsi);
+	if (ret) {
+		drm_panel_detach(ps_bridge->panel);
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct drm_bridge_funcs ps8640_bridge_funcs = {
+	.attach = ps8640_bridge_attach,
+	.disable = ps8640_disable,
+	.post_disable = ps8640_post_disable,
+	.pre_enable = ps8640_pre_enable,
+	.enable = ps8640_enable,
+};
+
+static ssize_t ps8640_fw_file_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", ps_bridge->fw_file);
+}
+
+static int ps8640_update_file_name(struct device *dev, char **file_name,
+				   const char *buf, size_t count)
+{
+	char *new_file_name;
+
+	/* Simple sanity check */
+	if (count > 64) {
+		dev_warn(dev, "File name too long\n");
+		return -EINVAL;
+	}
+
+	new_file_name = devm_kmalloc(dev, count + 1, GFP_KERNEL);
+	if (!new_file_name)
+		return -ENOMEM;
+
+	memcpy(new_file_name, buf, count + 1);
+
+	/* Echo into the sysfs entry may append newline at the end of buf */
+	if (new_file_name[count - 1] == '\n')
+		count--;
+
+	new_file_name[count] = '\0';
+
+	if (*file_name)
+		devm_kfree(dev, *file_name);
+
+	*file_name = new_file_name;
+
+	return 0;
+}
+
+/* Firmware Version is returned as Major.Minor.Build */
+static ssize_t ps8640_fw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
+			 info->version & 0xff);
+}
+
+/* Hardware Version is returned as FamilyID.VariantID */
+static ssize_t ps8640_hw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
+			 info->variant_id);
+}
+
+static int ps8640_spi_send_cmd(struct ps8640 *ps_bridge, u8 *cmd, u8 cmd_len)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 i;
+	int ret;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	if (ret)
+		goto err;
+
+	/* write command in write port */
+	for (i = 0; i < cmd_len; i++) {
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
+		if (ret)
+			goto err;
+	}
+	/* command length */
+	ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, cmd_len - 1);
+	if (ret)
+		goto err;
+	/* trigger read */
+	ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL, TRIGGER_NO_READBACK);
+	if (ret)
+		goto err;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&client->dev, "send command err: %d\n", ret);
+	return ret;
+}
+
+static int ps8640_wait_spi_ready(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 spi_rdy_st, retry_cnt = 0;
+
+	do {
+		ps8640_regr(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
+		msleep(20);
+		if ((retry_cnt == SPI_MAX_RETRY_CNT) &&
+		    ((spi_rdy_st & 0x0c) != 0x0c)) {
+			dev_err(&client->dev, "wait spi ready timeout\n");
+			return -EBUSY;
+		}
+	} while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
+		 (spi_rdy_st & 0x0c) == 0x0c);
+
+	return 0;
+}
+
+static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 spi_status, retry_cnt = 0;
+	int ret;
+
+	do {
+		/* 0x05 RDSR; Read-Status-Register */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, 0x05);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* command length */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, 0x00);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* trigger read */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL,
+				       TRIGGER_READBACK);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* delay for cmd send */
+		usleep_range(100, 300);
+		/* wait for SPI ROM until not busy */
+		ret = ps8640_regr(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
+		if (ret)
+			goto err_send_cmd_exit;
+	} while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
+		 (spi_status & 0x0c) == 0x0c);
+
+	if ((retry_cnt > SPI_MAX_RETRY_CNT) && (spi_status & 0x0c) != 0x0c) {
+		ret = -EBUSY;
+		dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
+		goto err_timeout;
+	}
+
+	return 0;
+
+err_send_cmd_exit:
+	dev_err(&client->dev, "send command err: %d\n", ret);
+
+err_timeout:
+	return ret;
+}
+
+static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	int ret;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_wait_spi_ready(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_wait_spi_nobusy(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+	if (ret)
+		goto exit;
+
+exit:
+	if (ret)
+		dev_err(&client->dev, "wait ps8640 rom idle fail: %d\n", ret);
+
+	return ret;
+}
+
+static int ps8640_spi_dl_mode(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	int ret;
+
+	/* switch ps8640 mode to spi dl mode */
+	gpiod_set_value(ps_bridge->gpio_mode_sel_n, 0);
+
+	/* reset spi interface */
+	ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0xc0);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0x40);
+	if (ret)
+		goto exit;
+
+exit:
+	if (ret)
+		dev_err(&client->dev, "fail reset spi interface: %d\n", ret);
+
+	return ret;
+}
+
+static int ps8640_rom_prepare(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	struct device *dev = &client->dev;
+	u8 i, cmd[2];
+	int ret;
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "failed enable-write-status-register: %d\n", ret);
+		return ret;
+	}
+
+	/* disable all protection */
+	cmd[0] = 0x01;
+	cmd[1] = 0x00;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 2);
+	if (ret) {
+		dev_err(dev, "fail disable all protection: %d\n", ret);
+		return ret;
+	}
+
+	/* wait for SPI module ready */
+	ret = ps8640_wait_rom_idle(ps_bridge);
+	if (ret) {
+		dev_err(dev, "fail wait rom idle: %d\n", ret);
+		return ret;
+	}
+
+	ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	for (i = 0; i < 6; i++)
+		ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
+	ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "fail enable-write-status-register: %d\n", ret);
+		return ret;
+	}
+
+	/* chip erase command */
+	cmd[0] = 0xc7;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "fail disable all protection: %d\n", ret);
+		return ret;
+	}
+
+	ret = ps8640_wait_rom_idle(ps_bridge);
+	if (ret) {
+		dev_err(dev, "fail wait rom idle: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
+				    const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct ps8640_info *info = &ps_bridge->info;
+	u16 fw_chip_id, fw_version_id;
+
+	/*
+	 * Get the chip_id from the firmware. Make sure that it is the
+	 * right controller to do the firmware and config update.
+	 */
+	fw_chip_id = get_unaligned_le16(fw->data + FW_CHIP_ID_OFFSET);
+
+	if (fw_chip_id != 0x8640) {
+		dev_err(&client->dev,
+			"chip id mismatch: fw 0x%x vs. chip 0x8640\n",
+			fw_chip_id);
+		return -ENODEV;
+	}
+
+	fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
+
+	if (fw_chip_id != info->version) {
+		dev_err(&client->dev,
+			"fw version mismatch: fw %d.%d vs. chip %d.%d\n",
+			fw_version_id >> 8, fw_version_id & 0xff,
+			info->version >> 8, info->version & 0xff);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int ps8640_write_rom(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct device *dev = &client->dev;
+	struct i2c_client *client2 = ps_bridge->page[2];
+	struct i2c_client *client7 = ps_bridge->page[7];
+	unsigned int pos = 0;
+	u8 buf[257], rom_page_id_buf[3];
+	int ret;
+	u16 cpy_len;
+
+	ps8640_regw_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
+	msleep(100);
+	ps8640_regw_byte(client2, PAGE2_SPI_CFG3, 0x00);
+
+	while (pos < fw->size) {
+		rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
+		rom_page_id_buf[1] = (pos >> 8) & 0xff;
+		rom_page_id_buf[2] = (pos >> 16) & 0xff;
+		ret = ps8640_regw_bytes(client2, rom_page_id_buf, 3);
+		if (ret)
+			goto error;
+		cpy_len = fw->size >= 256 + pos ? 256 : fw->size - pos;
+		buf[0] = 0;
+		memcpy(buf + 1, fw->data + pos, cpy_len);
+		ret = ps8640_regw_bytes(client7, buf, cpy_len + 1);
+		if (ret)
+			goto error;
+
+		pos += cpy_len;
+
+		dev_dbg(dev, "fw update completed %u / %zu bytes\n", pos,
+			fw->size);
+	}
+	return 0;
+
+error:
+	dev_err(dev, "failed write extenal flash, %d\n", ret);
+	return ret;
+}
+
+static int ps8640_spi_normal_mode(struct ps8640 *ps_bridge)
+{
+	u8 cmd[2];
+	struct i2c_client *client = ps_bridge->page[2];
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+
+	/* protect BPL/BP0/BP1 */
+	cmd[0] = 0x01;
+	cmd[1] = 0x8c;
+	ps8640_spi_send_cmd(ps_bridge, cmd, 2);
+
+	/* wait for SPI rom ready */
+	ps8640_wait_rom_idle(ps_bridge);
+
+	/* disable PS8640 mapping function */
+	ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
+
+	gpiod_set_value(ps_bridge->gpio_mode_sel_n, 1);
+	return 0;
+}
+
+static int ps8640_enter_bl(struct ps8640 *ps_bridge)
+{
+	int ret;
+
+	ret = ps8640_spi_dl_mode(ps_bridge);
+	if (ret)
+		return ret;
+
+	ps_bridge->in_fw_update = true;
+	return 0;
+}
+
+static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	ps_bridge->in_fw_update = false;
+	ps8640_spi_normal_mode(ps_bridge);
+}
+
+static int ps8640_load_fw(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct device *dev = &client->dev;
+	int ret;
+	bool ps8640_status_backup = ps_bridge->enabled;
+
+	if (!ps_bridge->in_fw_update) {
+		if (!ps8640_status_backup)
+			ps8640_pre_enable(&ps_bridge->bridge);
+
+		ret = ps8640_enter_bl(ps_bridge);
+		if (ret)
+			goto exit;
+	}
+
+	ret = ps8640_validate_firmware(ps_bridge, fw);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_rom_prepare(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_write_rom(ps_bridge, fw);
+
+exit:
+	if (ret)
+		dev_err(dev, "Failed to load firmware, %d\n", ret);
+
+	ps8640_exit_bl(ps_bridge, fw);
+	if (!ps8640_status_backup)
+		ps8640_post_disable(&ps_bridge->bridge);
+	return ret;
+}
+
+static ssize_t ps8640_update_fw_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	const struct firmware *fw;
+	int error;
+
+	error = request_firmware(&fw, ps_bridge->fw_file, dev);
+	if (error) {
+		dev_err(dev, "Unable to open firmware %s: %d\n",
+			ps_bridge->fw_file, error);
+		return error;
+	}
+
+	error = ps8640_load_fw(ps_bridge, fw);
+	if (error)
+		dev_err(dev, "The firmware update failed(%d)\n", error);
+	else
+		dev_info(dev, "The firmware update succeeded\n");
+
+	release_firmware(fw);
+	return error ? error : count;
+}
+
+static DEVICE_ATTR(fw_file, S_IRUGO, ps8640_fw_file_show, NULL);
+static DEVICE_ATTR(fw_version, S_IRUGO, ps8640_fw_version_show, NULL);
+static DEVICE_ATTR(hw_version, S_IRUGO, ps8640_hw_version_show, NULL);
+static DEVICE_ATTR(update_fw, S_IWUSR, NULL, ps8640_update_fw_store);
+
+static struct attribute *ps8640_attrs[] = {
+	&dev_attr_fw_file.attr,
+	&dev_attr_fw_version.attr,
+	&dev_attr_hw_version.attr,
+	&dev_attr_update_fw.attr,
+	NULL
+};
+
+static const struct attribute_group ps8640_attr_group = {
+	.attrs = ps8640_attrs,
+};
+
+static void ps8640_remove_sysfs_group(void *data)
+{
+	struct ps8640 *ps_bridge = data;
+
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+}
+
+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 *port, *out_ep;
+	struct device_node *panel_node = NULL;
+	int i, ret;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
+				      GFP_KERNEL);
+	if (!ps_bridge) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	/* port@1 is ps8640 output port */
+	port = of_graph_get_port_by_id(np, 1);
+	if (port) {
+		out_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		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) {
+			ret = -EPROBE_DEFER;
+			goto exit;
+		}
+	}
+
+	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
+	if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
+		ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
+		dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");
+	if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
+		ret = PTR_ERR(ps_bridge->pwr_1v2_supply);
+		dev_err(dev, "cannot get vdd12 supply: %d\n", ret);
+		goto exit;
+	}
+
+	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);
+		dev_err(dev, "cannot get gpio_mode_sel_n %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->gpio_slp_n = devm_gpiod_get(&client->dev, "sleep",
+					       GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_slp_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_slp_n);
+		dev_err(dev, "cannot get gpio_slp_n: %d\n", ret);
+		goto exit;
+	}
+
+	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);
+		dev_err(dev, "cannot get gpio_rst_n: %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
+	ps_bridge->bridge.of_node = dev->of_node;
+	ret = drm_bridge_add(&ps_bridge->bridge);
+	if (ret) {
+		dev_err(dev, "Failed to add bridge: %d\n", ret);
+		goto exit;
+	}
+
+	ret = ps8640_update_file_name(&client->dev, &ps_bridge->fw_file,
+				      PS_FW_NAME, strlen(PS_FW_NAME));
+	if (ret) {
+		dev_err(dev, "failed to update file name: %d\n", ret);
+		goto exit_drm_bridge_remove;
+	}
+
+	ps_bridge->page[0] = client;
+
+	/*
+	 * ps8640 uses multiple addresses, use dummy devices for them
+	 * page[0]: for DP control
+	 * page[1]: for VIDEO Bridge
+	 * page[2]: for control top
+	 * page[3]: for DSI Link Control1
+	 * page[4]: for MIPI Phy
+	 * page[5]: for VPLL
+	 * page[6]: for DSI Link Control2
+	 * page[7]: for spi rom mapping
+	 */
+	for (i = 1; i < 8; i++) {
+		ps_bridge->page[i] = i2c_new_dummy(client->adapter,
+						   client->addr + i);
+		if (!ps_bridge->page[i]) {
+			dev_err(dev, "failed i2c dummy device, address%02x\n",
+				client->addr + i);
+			ret = -EBUSY;
+			goto exit_dummy;
+		}
+	}
+	i2c_set_clientdata(client, ps_bridge);
+
+	ret = sysfs_create_group(&client->dev.kobj, &ps8640_attr_group);
+	if (ret) {
+		dev_err(dev, "failed to create sysfs entries: %d\n", ret);
+		goto exit_dummy;
+	}
+
+	ret = devm_add_action(dev, ps8640_remove_sysfs_group, ps_bridge);
+	if (ret) {
+		dev_err(dev, "failed to add sysfs cleanup action: %d\n", ret);
+		goto exit_remove_sysfs;
+	}
+	return 0;
+
+exit_remove_sysfs:
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+exit_dummy:
+	for (i = 1; i < 8; i++)
+		if (ps_bridge->page[i])
+			i2c_unregister_device(ps_bridge->page[i]);
+exit_drm_bridge_remove:
+	drm_bridge_remove(&ps_bridge->bridge);
+exit:
+	return ret;
+}
+
+static int ps8640_remove(struct i2c_client *client)
+{
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 1; i < 8; i++)
+		i2c_unregister_device(ps_bridge->page[i]);
+
+	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",
+		.of_match_table = ps8640_match,
+	},
+};
+module_i2c_driver(ps8640_driver);
+
+MODULE_AUTHOR("Jitao Shi <jitao.shi-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>");
+MODULE_AUTHOR("CK Hu <ck.hu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>");
+MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.9.5

[PATCH v8 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>
---
Changes since v7:
 - Change ps8640_regw to ps8640_regw_bytes and remove devm_kzalloc
 - Fine tune ps8640 power squence
 - Add ps8640_pre_enable and ps8640_post_disable in ps8640_get_modes
 - Remove unnecessary codes and comments

The following patches are needed to support dsi host through none dsi bus:

https://patchwork.kernel.org/patch/7818431/ ("drm/dsi: check for CONFIG_OF when defining of_mipi_dsi_device_add")
https://patchwork.kernel.org/patch/7818471/ ("drm/dsi: Refactor device creation")
https://patchwork.kernel.org/patch/7818501/ ("drm/dsi: Try to match non-DT dsi devices")
https://patchwork.kernel.org/patch/7818531/ ("drm/dsi: Check for used channels")
https://patchwork.kernel.org/patch/7818561/ ("drm/dsi: Add routine to unregister dsi device")
https://patchwork.kernel.org/patch/7818541/ ("drm/dsi: Get DSI host by DT device node")
---
 drivers/gpu/drm/bridge/Kconfig         |   10 +
 drivers/gpu/drm/bridge/Makefile        |    1 +
 drivers/gpu/drm/bridge/parade-ps8640.c | 1084 ++++++++++++++++++++++++++++++++
 3 files changed, 1095 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 27e2022..fe8ad50 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -40,4 +40,14 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_PARADE_PS8640
+	tristate "Parade PS8640 MIPI DSI to eDP Converter"
+	depends on OF && I2C
+	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 f13c33d..fbe38dc 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.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..0230ab5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,1084 @@
+/*
+ * 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/delay.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+#include <drm/drm_panel.h>
+
+#include <drmP.h>
+#include <drm_atomic_helper.h>
+#include <drm_crtc_helper.h>
+#include <drm_crtc.h>
+#include <drm_mipi_dsi.h>
+
+#define PAGE2_SPI_CFG3		0x82
+#define I2C_TO_SPI_RESET	0x20
+#define PAGE2_ROMADD_BYTE1	0x8e
+#define PAGE2_ROMADD_BYTE2	0x8f
+#define PAGE2_SWSPI_WDATA	0x90
+#define PAGE2_SWSPI_RDATA	0x91
+#define PAGE2_SWSPI_LEN		0x92
+#define PAGE2_SWSPI_CTL		0x93
+#define TRIGGER_NO_READBACK	0x05
+#define TRIGGER_READBACK	0x01
+#define PAGE2_SPI_STATUS	0x9e
+#define PAGE2_GPIO_L		0xa6
+#define PAGE2_GPIO_H		0xa7
+#define PS_GPIO9		BIT(1)
+#define PAGE2_IROM_CTRL		0xb0
+#define IROM_ENABLE		0xc0
+#define IROM_DISABLE		0x80
+#define PAGE2_SW_REST		0xbc
+#define PAGE2_ENCTLSPI_WR	0xda
+#define PAGE2_I2C_BYPASS	0xea
+#define I2C_BYPASS_EN		0xd0
+
+#define PAGE3_SET_ADD		0xfe
+#define PAGE3_SET_VAL		0xff
+#define VDO_CTL_ADD		0x13
+#define VDO_DIS			0x18
+#define VDO_EN			0x1c
+
+#define PAGE4_REV_L		0xf0
+#define PAGE4_REV_H		0xf1
+#define PAGE4_CHIP_L		0xf2
+#define PAGE4_CHIP_H		0xf3
+
+/* Firmware */
+#define SPI_MAX_RETRY_CNT	8
+#define PS_FW_NAME		"ps864x_fw.bin"
+
+#define FW_CHIP_ID_OFFSET	0
+#define FW_VERSION_OFFSET	2
+
+#define bridge_to_ps8640(e)	container_of(e, struct ps8640, bridge)
+#define connector_to_ps8640(e)	container_of(e, struct ps8640, connector)
+
+struct ps8640_info {
+	u8 family_id;
+	u8 variant_id;
+	u16 version;
+};
+
+struct ps8640 {
+	struct drm_connector connector;
+	struct drm_bridge bridge;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *page[8];
+	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;
+	bool enabled;
+
+	/* firmware file name */
+	bool in_fw_update;
+	char *fw_file;
+	struct ps8640_info info;
+};
+
+static const u8 enc_ctrl_code[6] = {0xaa, 0x55, 0x50, 0x41, 0x52, 0x44};
+
+static int ps8640_regr(struct i2c_client *client, u8 reg, u8 *data,
+		       u16 data_len)
+{
+	int ret;
+	struct i2c_msg msgs[] = {
+		{
+		 .addr = client->addr,
+		 .flags = 0,
+		 .len = 1,
+		 .buf = &reg,
+		 },
+		{
+		 .addr = client->addr,
+		 .flags = I2C_M_RD,
+		 .len = data_len,
+		 .buf = data,
+		 }
+	};
+
+	ret = i2c_transfer(client->adapter, msgs, 2);
+
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_regw_bytes(struct i2c_client *client, u8 *data,
+			     u16 data_len)
+{
+	int ret;
+	struct i2c_msg msg;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = data_len;
+	msg.buf = data;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_regw_byte(struct i2c_client *client, u8 reg,  u8 data)
+{
+	int ret;
+	struct i2c_msg msg;
+	u8 buf[] = {reg, data};
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = sizeof(buf);
+	msg.buf = buf;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[5];
+	u8 fw_ver[2];
+
+	ps8640_regr(client, 0x4, fw_ver, 2);
+	ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
+
+	DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
+}
+
+static int ps8640_bridge_enable(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[3];
+	int ret;
+	u8 vdo_ctrl_buf[3] = {PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN};
+
+	ret = ps8640_regw_bytes(client, vdo_ctrl_buf, 3);
+	return ret;
+}
+
+static void ps8640_pre_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct i2c_client *client = ps_bridge->page[2];
+	int err, retry_cnt = 0;
+	u8 set_vdo_done;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (ps_bridge->enabled)
+		return;
+
+	err = drm_panel_prepare(ps_bridge->panel);
+	if (err < 0) {
+		DRM_ERROR("failed to prepare panel: %d\n", err);
+		return;
+	}
+
+	gpiod_set_value(ps_bridge->gpio_slp_n, 1);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+
+	err = regulator_enable(ps_bridge->pwr_1v2_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable vdd12-supply: %d\n", err);
+		goto err_panel_unprepare;
+	}
+
+	err = regulator_enable(ps_bridge->pwr_3v3_supply);
+	if (err < 0) {
+		DRM_ERROR("failed to enable vdd33-supply: %d\n", err);
+		goto err_regulator_1v2_disable;
+	}
+
+	usleep_range(500, 700);
+	gpiod_set_value(ps_bridge->gpio_rst_n, 1);
+
+	/*
+	 * Wait for the ps8640 embed mcu ready
+	 * First wait 200ms and then check the mcu ready flag every 20ms
+	 */
+	msleep(200);
+	do {
+		err = ps8640_regr(client, PAGE2_GPIO_H, &set_vdo_done, 1);
+		if (err < 0) {
+			DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
+			goto err_regulator_1v2_disable;
+		}
+		msleep(20);
+	} while ((retry_cnt++ < 10) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
+
+	if (ps_bridge->info.version == 0)
+		ps8640_get_mcu_fw_version(ps_bridge);
+	/* Switch access edp panel's edid through i2c */
+	ps8640_regw_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
+	ps_bridge->enabled = true;
+
+	return;
+
+err_regulator_1v2_disable:
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+err_panel_unprepare:
+	drm_panel_unprepare(ps_bridge->panel);
+}
+
+static void ps8640_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = ps8640_bridge_enable(ps_bridge);
+	if (err)
+		DRM_ERROR("failed to enable unmutevideo: %d\n", err);
+
+	err = drm_panel_enable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to enable panel: %d\n", err);
+}
+
+static void ps8640_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = drm_panel_disable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to disable panel: %d\n", err);
+}
+
+static void ps8640_post_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (!ps_bridge->enabled)
+		return;
+
+	ps_bridge->enabled = false;
+
+	gpiod_set_value(ps_bridge->gpio_rst_n, 0);
+	gpiod_set_value(ps_bridge->gpio_slp_n, 0);
+	regulator_disable(ps_bridge->pwr_3v3_supply);
+	regulator_disable(ps_bridge->pwr_1v2_supply);
+
+	err = drm_panel_unprepare(ps_bridge->panel);
+	if (err)
+		DRM_ERROR("failed to unprepare panel: %d\n", err);
+}
+
+static int ps8640_get_modes(struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge = connector_to_ps8640(connector);
+	bool power_off;
+	int num_modes = 0;
+
+	power_off = !ps_bridge->enabled;
+	ps8640_pre_enable(&ps_bridge->bridge);
+
+	num_modes = drm_panel_get_modes(ps_bridge->panel);
+
+	if (power_off)
+		ps8640_post_disable(&ps_bridge->bridge);
+
+	return num_modes;
+}
+
+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);
+	struct device *dev = &ps_bridge->page[0]->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *port, *in_ep;
+	struct device_node *dsi_node = NULL;
+	struct mipi_dsi_host *host = ps_bridge->dsi->host;
+	int ret;
+
+	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: %d\n", ret);
+		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);
+
+	/* port at 0 is ps8640 dsi input port */
+	port = of_graph_get_port_by_id(np, 0);
+	if (port) {
+		in_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		if (in_ep) {
+			dsi_node = of_graph_get_remote_port_parent(in_ep);
+			of_node_put(in_ep);
+		}
+	}
+	if (dsi_node) {
+		host = of_find_mipi_dsi_host_by_node(dsi_node);
+		of_node_put(dsi_node);
+		if (!host)
+			return -ENODEV;
+	}
+
+	ps_bridge->dsi->host = host;
+	ps_bridge->dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+				     MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	ps_bridge->dsi->format = MIPI_DSI_FMT_RGB888;
+	ps_bridge->dsi->lanes = 4;
+	ret = mipi_dsi_attach(ps_bridge->dsi);
+	if (ret) {
+		drm_panel_detach(ps_bridge->panel);
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct drm_bridge_funcs ps8640_bridge_funcs = {
+	.attach = ps8640_bridge_attach,
+	.disable = ps8640_disable,
+	.post_disable = ps8640_post_disable,
+	.pre_enable = ps8640_pre_enable,
+	.enable = ps8640_enable,
+};
+
+static ssize_t ps8640_fw_file_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", ps_bridge->fw_file);
+}
+
+static int ps8640_update_file_name(struct device *dev, char **file_name,
+				   const char *buf, size_t count)
+{
+	char *new_file_name;
+
+	/* Simple sanity check */
+	if (count > 64) {
+		dev_warn(dev, "File name too long\n");
+		return -EINVAL;
+	}
+
+	new_file_name = devm_kmalloc(dev, count + 1, GFP_KERNEL);
+	if (!new_file_name)
+		return -ENOMEM;
+
+	memcpy(new_file_name, buf, count + 1);
+
+	/* Echo into the sysfs entry may append newline at the end of buf */
+	if (new_file_name[count - 1] == '\n')
+		count--;
+
+	new_file_name[count] = '\0';
+
+	if (*file_name)
+		devm_kfree(dev, *file_name);
+
+	*file_name = new_file_name;
+
+	return 0;
+}
+
+/* Firmware Version is returned as Major.Minor.Build */
+static ssize_t ps8640_fw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
+			 info->version & 0xff);
+}
+
+/* Hardware Version is returned as FamilyID.VariantID */
+static ssize_t ps8640_hw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
+			 info->variant_id);
+}
+
+static int ps8640_spi_send_cmd(struct ps8640 *ps_bridge, u8 *cmd, u8 cmd_len)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 i;
+	int ret;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	if (ret)
+		goto err;
+
+	/* write command in write port */
+	for (i = 0; i < cmd_len; i++) {
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
+		if (ret)
+			goto err;
+	}
+	/* command length */
+	ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, cmd_len - 1);
+	if (ret)
+		goto err;
+	/* trigger read */
+	ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL, TRIGGER_NO_READBACK);
+	if (ret)
+		goto err;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&client->dev, "send command err: %d\n", ret);
+	return ret;
+}
+
+static int ps8640_wait_spi_ready(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 spi_rdy_st, retry_cnt = 0;
+
+	do {
+		ps8640_regr(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
+		msleep(20);
+		if ((retry_cnt == SPI_MAX_RETRY_CNT) &&
+		    ((spi_rdy_st & 0x0c) != 0x0c)) {
+			dev_err(&client->dev, "wait spi ready timeout\n");
+			return -EBUSY;
+		}
+	} while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
+		 (spi_rdy_st & 0x0c) == 0x0c);
+
+	return 0;
+}
+
+static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	u8 spi_status, retry_cnt = 0;
+	int ret;
+
+	do {
+		/* 0x05 RDSR; Read-Status-Register */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, 0x05);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* command length */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, 0x00);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* trigger read */
+		ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL,
+				       TRIGGER_READBACK);
+		if (ret)
+			goto err_send_cmd_exit;
+
+		/* delay for cmd send */
+		usleep_range(100, 300);
+		/* wait for SPI ROM until not busy */
+		ret = ps8640_regr(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
+		if (ret)
+			goto err_send_cmd_exit;
+	} while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
+		 (spi_status & 0x0c) == 0x0c);
+
+	if ((retry_cnt > SPI_MAX_RETRY_CNT) && (spi_status & 0x0c) != 0x0c) {
+		ret = -EBUSY;
+		dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
+		goto err_timeout;
+	}
+
+	return 0;
+
+err_send_cmd_exit:
+	dev_err(&client->dev, "send command err: %d\n", ret);
+
+err_timeout:
+	return ret;
+}
+
+static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	int ret;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_wait_spi_ready(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_wait_spi_nobusy(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+	if (ret)
+		goto exit;
+
+exit:
+	if (ret)
+		dev_err(&client->dev, "wait ps8640 rom idle fail: %d\n", ret);
+
+	return ret;
+}
+
+static int ps8640_spi_dl_mode(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	int ret;
+
+	/* switch ps8640 mode to spi dl mode */
+	gpiod_set_value(ps_bridge->gpio_mode_sel_n, 0);
+
+	/* reset spi interface */
+	ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0xc0);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0x40);
+	if (ret)
+		goto exit;
+
+exit:
+	if (ret)
+		dev_err(&client->dev, "fail reset spi interface: %d\n", ret);
+
+	return ret;
+}
+
+static int ps8640_rom_prepare(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[2];
+	struct device *dev = &client->dev;
+	u8 i, cmd[2];
+	int ret;
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "failed enable-write-status-register: %d\n", ret);
+		return ret;
+	}
+
+	/* disable all protection */
+	cmd[0] = 0x01;
+	cmd[1] = 0x00;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 2);
+	if (ret) {
+		dev_err(dev, "fail disable all protection: %d\n", ret);
+		return ret;
+	}
+
+	/* wait for SPI module ready */
+	ret = ps8640_wait_rom_idle(ps_bridge);
+	if (ret) {
+		dev_err(dev, "fail wait rom idle: %d\n", ret);
+		return ret;
+	}
+
+	ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
+	for (i = 0; i < 6; i++)
+		ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
+	ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "fail enable-write-status-register: %d\n", ret);
+		return ret;
+	}
+
+	/* chip erase command */
+	cmd[0] = 0xc7;
+	ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+	if (ret) {
+		dev_err(dev, "fail disable all protection: %d\n", ret);
+		return ret;
+	}
+
+	ret = ps8640_wait_rom_idle(ps_bridge);
+	if (ret) {
+		dev_err(dev, "fail wait rom idle: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
+				    const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct ps8640_info *info = &ps_bridge->info;
+	u16 fw_chip_id, fw_version_id;
+
+	/*
+	 * Get the chip_id from the firmware. Make sure that it is the
+	 * right controller to do the firmware and config update.
+	 */
+	fw_chip_id = get_unaligned_le16(fw->data + FW_CHIP_ID_OFFSET);
+
+	if (fw_chip_id != 0x8640) {
+		dev_err(&client->dev,
+			"chip id mismatch: fw 0x%x vs. chip 0x8640\n",
+			fw_chip_id);
+		return -ENODEV;
+	}
+
+	fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
+
+	if (fw_chip_id != info->version) {
+		dev_err(&client->dev,
+			"fw version mismatch: fw %d.%d vs. chip %d.%d\n",
+			fw_version_id >> 8, fw_version_id & 0xff,
+			info->version >> 8, info->version & 0xff);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int ps8640_write_rom(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct device *dev = &client->dev;
+	struct i2c_client *client2 = ps_bridge->page[2];
+	struct i2c_client *client7 = ps_bridge->page[7];
+	unsigned int pos = 0;
+	u8 buf[257], rom_page_id_buf[3];
+	int ret;
+	u16 cpy_len;
+
+	ps8640_regw_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
+	msleep(100);
+	ps8640_regw_byte(client2, PAGE2_SPI_CFG3, 0x00);
+
+	while (pos < fw->size) {
+		rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
+		rom_page_id_buf[1] = (pos >> 8) & 0xff;
+		rom_page_id_buf[2] = (pos >> 16) & 0xff;
+		ret = ps8640_regw_bytes(client2, rom_page_id_buf, 3);
+		if (ret)
+			goto error;
+		cpy_len = fw->size >= 256 + pos ? 256 : fw->size - pos;
+		buf[0] = 0;
+		memcpy(buf + 1, fw->data + pos, cpy_len);
+		ret = ps8640_regw_bytes(client7, buf, cpy_len + 1);
+		if (ret)
+			goto error;
+
+		pos += cpy_len;
+
+		dev_dbg(dev, "fw update completed %u / %zu bytes\n", pos,
+			fw->size);
+	}
+	return 0;
+
+error:
+	dev_err(dev, "failed write extenal flash, %d\n", ret);
+	return ret;
+}
+
+static int ps8640_spi_normal_mode(struct ps8640 *ps_bridge)
+{
+	u8 cmd[2];
+	struct i2c_client *client = ps_bridge->page[2];
+
+	/* Enable-Write-Status-Register */
+	cmd[0] = 0x06;
+	ps8640_spi_send_cmd(ps_bridge, cmd, 1);
+
+	/* protect BPL/BP0/BP1 */
+	cmd[0] = 0x01;
+	cmd[1] = 0x8c;
+	ps8640_spi_send_cmd(ps_bridge, cmd, 2);
+
+	/* wait for SPI rom ready */
+	ps8640_wait_rom_idle(ps_bridge);
+
+	/* disable PS8640 mapping function */
+	ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
+
+	gpiod_set_value(ps_bridge->gpio_mode_sel_n, 1);
+	return 0;
+}
+
+static int ps8640_enter_bl(struct ps8640 *ps_bridge)
+{
+	int ret;
+
+	ret = ps8640_spi_dl_mode(ps_bridge);
+	if (ret)
+		return ret;
+
+	ps_bridge->in_fw_update = true;
+	return 0;
+}
+
+static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	ps_bridge->in_fw_update = false;
+	ps8640_spi_normal_mode(ps_bridge);
+}
+
+static int ps8640_load_fw(struct ps8640 *ps_bridge, const struct firmware *fw)
+{
+	struct i2c_client *client = ps_bridge->page[0];
+	struct device *dev = &client->dev;
+	int ret;
+	bool ps8640_status_backup = ps_bridge->enabled;
+
+	if (!ps_bridge->in_fw_update) {
+		if (!ps8640_status_backup)
+			ps8640_pre_enable(&ps_bridge->bridge);
+
+		ret = ps8640_enter_bl(ps_bridge);
+		if (ret)
+			goto exit;
+	}
+
+	ret = ps8640_validate_firmware(ps_bridge, fw);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_rom_prepare(ps_bridge);
+	if (ret)
+		goto exit;
+
+	ret = ps8640_write_rom(ps_bridge, fw);
+
+exit:
+	if (ret)
+		dev_err(dev, "Failed to load firmware, %d\n", ret);
+
+	ps8640_exit_bl(ps_bridge, fw);
+	if (!ps8640_status_backup)
+		ps8640_post_disable(&ps_bridge->bridge);
+	return ret;
+}
+
+static ssize_t ps8640_update_fw_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	const struct firmware *fw;
+	int error;
+
+	error = request_firmware(&fw, ps_bridge->fw_file, dev);
+	if (error) {
+		dev_err(dev, "Unable to open firmware %s: %d\n",
+			ps_bridge->fw_file, error);
+		return error;
+	}
+
+	error = ps8640_load_fw(ps_bridge, fw);
+	if (error)
+		dev_err(dev, "The firmware update failed(%d)\n", error);
+	else
+		dev_info(dev, "The firmware update succeeded\n");
+
+	release_firmware(fw);
+	return error ? error : count;
+}
+
+static DEVICE_ATTR(fw_file, S_IRUGO, ps8640_fw_file_show, NULL);
+static DEVICE_ATTR(fw_version, S_IRUGO, ps8640_fw_version_show, NULL);
+static DEVICE_ATTR(hw_version, S_IRUGO, ps8640_hw_version_show, NULL);
+static DEVICE_ATTR(update_fw, S_IWUSR, NULL, ps8640_update_fw_store);
+
+static struct attribute *ps8640_attrs[] = {
+	&dev_attr_fw_file.attr,
+	&dev_attr_fw_version.attr,
+	&dev_attr_hw_version.attr,
+	&dev_attr_update_fw.attr,
+	NULL
+};
+
+static const struct attribute_group ps8640_attr_group = {
+	.attrs = ps8640_attrs,
+};
+
+static void ps8640_remove_sysfs_group(void *data)
+{
+	struct ps8640 *ps_bridge = data;
+
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+}
+
+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 *port, *out_ep;
+	struct device_node *panel_node = NULL;
+	int i, ret;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
+				      GFP_KERNEL);
+	if (!ps_bridge) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	/* port at 1 is ps8640 output port */
+	port = of_graph_get_port_by_id(np, 1);
+	if (port) {
+		out_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		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) {
+			ret = -EPROBE_DEFER;
+			goto exit;
+		}
+	}
+
+	ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
+	if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
+		ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
+		dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");
+	if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
+		ret = PTR_ERR(ps_bridge->pwr_1v2_supply);
+		dev_err(dev, "cannot get vdd12 supply: %d\n", ret);
+		goto exit;
+	}
+
+	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);
+		dev_err(dev, "cannot get gpio_mode_sel_n %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->gpio_slp_n = devm_gpiod_get(&client->dev, "sleep",
+					       GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_slp_n)) {
+		ret = PTR_ERR(ps_bridge->gpio_slp_n);
+		dev_err(dev, "cannot get gpio_slp_n: %d\n", ret);
+		goto exit;
+	}
+
+	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);
+		dev_err(dev, "cannot get gpio_rst_n: %d\n", ret);
+		goto exit;
+	}
+
+	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
+	ps_bridge->bridge.of_node = dev->of_node;
+	ret = drm_bridge_add(&ps_bridge->bridge);
+	if (ret) {
+		dev_err(dev, "Failed to add bridge: %d\n", ret);
+		goto exit;
+	}
+
+	ret = ps8640_update_file_name(&client->dev, &ps_bridge->fw_file,
+				      PS_FW_NAME, strlen(PS_FW_NAME));
+	if (ret) {
+		dev_err(dev, "failed to update file name: %d\n", ret);
+		goto exit_drm_bridge_remove;
+	}
+
+	ps_bridge->page[0] = client;
+
+	/*
+	 * ps8640 uses multiple addresses, use dummy devices for them
+	 * page[0]: for DP control
+	 * page[1]: for VIDEO Bridge
+	 * page[2]: for control top
+	 * page[3]: for DSI Link Control1
+	 * page[4]: for MIPI Phy
+	 * page[5]: for VPLL
+	 * page[6]: for DSI Link Control2
+	 * page[7]: for spi rom mapping
+	 */
+	for (i = 1; i < 8; i++) {
+		ps_bridge->page[i] = i2c_new_dummy(client->adapter,
+						   client->addr + i);
+		if (!ps_bridge->page[i]) {
+			dev_err(dev, "failed i2c dummy device, address%02x\n",
+				client->addr + i);
+			ret = -EBUSY;
+			goto exit_dummy;
+		}
+	}
+	i2c_set_clientdata(client, ps_bridge);
+
+	ret = sysfs_create_group(&client->dev.kobj, &ps8640_attr_group);
+	if (ret) {
+		dev_err(dev, "failed to create sysfs entries: %d\n", ret);
+		goto exit_dummy;
+	}
+
+	ret = devm_add_action(dev, ps8640_remove_sysfs_group, ps_bridge);
+	if (ret) {
+		dev_err(dev, "failed to add sysfs cleanup action: %d\n", ret);
+		goto exit_remove_sysfs;
+	}
+	return 0;
+
+exit_remove_sysfs:
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+exit_dummy:
+	for (i = 1; i < 8; i++)
+		if (ps_bridge->page[i])
+			i2c_unregister_device(ps_bridge->page[i]);
+exit_drm_bridge_remove:
+	drm_bridge_remove(&ps_bridge->bridge);
+exit:
+	return ret;
+}
+
+static int ps8640_remove(struct i2c_client *client)
+{
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 1; i < 8; i++)
+		i2c_unregister_device(ps_bridge->page[i]);
+
+	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",
+		.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

Re: [PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1687 bytes --]

Hi Jitao,

[auto build test ERROR on drm/drm-next]
[also build test ERROR on v4.5-rc2 next-20160129]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/Jitao-Shi/Documentation-bridge-Add-documentation-for-ps8640-DT-properties/20160201-121553
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
config: x86_64-allmodconfig (attached as .config)
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

   drivers/gpu/drm/bridge/parade-ps8640.c: In function 'ps8640_bridge_attach':
>> drivers/gpu/drm/bridge/parade-ps8640.c:400:10: error: implicit declaration of function 'of_find_mipi_dsi_host_by_node' [-Werror=implicit-function-declaration]
      host = of_find_mipi_dsi_host_by_node(dsi_node);
             ^
>> drivers/gpu/drm/bridge/parade-ps8640.c:400:8: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      host = of_find_mipi_dsi_host_by_node(dsi_node);
           ^
   cc1: some warnings being treated as errors

vim +/of_find_mipi_dsi_host_by_node +400 drivers/gpu/drm/bridge/parade-ps8640.c

   394			if (in_ep) {
   395				dsi_node = of_graph_get_remote_port_parent(in_ep);
   396				of_node_put(in_ep);
   397			}
   398		}
   399		if (dsi_node) {
 > 400			host = of_find_mipi_dsi_host_by_node(dsi_node);
   401			of_node_put(dsi_node);
   402			if (!host)
   403				return -ENODEV;

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 50940 bytes --]

Re: [PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1687 bytes --]

Hi Jitao,

[auto build test ERROR on drm/drm-next]
[also build test ERROR on v4.5-rc2 next-20160129]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/Jitao-Shi/Documentation-bridge-Add-documentation-for-ps8640-DT-properties/20160201-121553
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
config: x86_64-allmodconfig (attached as .config)
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

   drivers/gpu/drm/bridge/parade-ps8640.c: In function 'ps8640_bridge_attach':
>> drivers/gpu/drm/bridge/parade-ps8640.c:400:10: error: implicit declaration of function 'of_find_mipi_dsi_host_by_node' [-Werror=implicit-function-declaration]
      host = of_find_mipi_dsi_host_by_node(dsi_node);
             ^
>> drivers/gpu/drm/bridge/parade-ps8640.c:400:8: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      host = of_find_mipi_dsi_host_by_node(dsi_node);
           ^
   cc1: some warnings being treated as errors

vim +/of_find_mipi_dsi_host_by_node +400 drivers/gpu/drm/bridge/parade-ps8640.c

   394			if (in_ep) {
   395				dsi_node = of_graph_get_remote_port_parent(in_ep);
   396				of_node_put(in_ep);
   397			}
   398		}
   399		if (dsi_node) {
 > 400			host = of_find_mipi_dsi_host_by_node(dsi_node);
   401			of_node_put(dsi_node);
   402			if (!host)
   403				return -ENODEV;

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 50940 bytes --]

[-- Attachment #3: Type: text/plain, Size: 200 bytes --]

_______________________________________________
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Linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

[PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[kbuild test robot]

Hi Jitao,

[auto build test ERROR on drm/drm-next]
[also build test ERROR on v4.5-rc2 next-20160129]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/Jitao-Shi/Documentation-bridge-Add-documentation-for-ps8640-DT-properties/20160201-121553
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
config: x86_64-allmodconfig (attached as .config)
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

   drivers/gpu/drm/bridge/parade-ps8640.c: In function 'ps8640_bridge_attach':
>> drivers/gpu/drm/bridge/parade-ps8640.c:400:10: error: implicit declaration of function 'of_find_mipi_dsi_host_by_node' [-Werror=implicit-function-declaration]
      host = of_find_mipi_dsi_host_by_node(dsi_node);
             ^
>> drivers/gpu/drm/bridge/parade-ps8640.c:400:8: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      host = of_find_mipi_dsi_host_by_node(dsi_node);
           ^
   cc1: some warnings being treated as errors

vim +/of_find_mipi_dsi_host_by_node +400 drivers/gpu/drm/bridge/parade-ps8640.c

   394			if (in_ep) {
   395				dsi_node = of_graph_get_remote_port_parent(in_ep);
   396				of_node_put(in_ep);
   397			}
   398		}
   399		if (dsi_node) {
 > 400			host = of_find_mipi_dsi_host_by_node(dsi_node);
   401			of_node_put(dsi_node);
   402			if (!host)
   403				return -ENODEV;

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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Re: [PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Daniel Kurtz]

On Mon, Feb 1, 2016 at 12:13 PM, Jitao Shi <jitao.shi@mediatek.com> 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 v7:
>  - Change ps8640_regw to ps8640_regw_bytes and remove devm_kzalloc
>  - Fine tune ps8640 power squence
>  - Add ps8640_pre_enable and ps8640_post_disable in ps8640_get_modes
>  - Remove unnecessary codes and comments
>
> The following patches are needed to support dsi host through none dsi bus:
>
> https://patchwork.kernel.org/patch/7818431/ ("drm/dsi: check for CONFIG_OF when defining of_mipi_dsi_device_add")
> https://patchwork.kernel.org/patch/7818471/ ("drm/dsi: Refactor device creation")
> https://patchwork.kernel.org/patch/7818501/ ("drm/dsi: Try to match non-DT dsi devices")
> https://patchwork.kernel.org/patch/7818531/ ("drm/dsi: Check for used channels")
> https://patchwork.kernel.org/patch/7818561/ ("drm/dsi: Add routine to unregister dsi device")
> https://patchwork.kernel.org/patch/7818541/ ("drm/dsi: Get DSI host by DT device node")
> ---
>  drivers/gpu/drm/bridge/Kconfig         |   10 +
>  drivers/gpu/drm/bridge/Makefile        |    1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c | 1084 ++++++++++++++++++++++++++++++++
>  3 files changed, 1095 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 27e2022..fe8ad50 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -40,4 +40,14 @@ config DRM_PARADE_PS8622
>         ---help---
>           Parade eDP-LVDS bridge chip driver.
>
> +config DRM_PARADE_PS8640
> +       tristate "Parade PS8640 MIPI DSI to eDP Converter"
> +       depends on OF && I2C
> +       select DRM_KMS_HELPER

I think this needs:

select DRM_MIPI_DSI

Otherwise:
drivers/gpu/drm/bridge/parade-ps8640.c:400: undefined reference to
`of_find_mipi_dsi_host_by_node'
drivers/gpu/drm/bridge/parade-ps8640.c:411: undefined reference to
`mipi_dsi_attach'

> +       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 f13c33d..fbe38dc 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.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..0230ab5
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,1084 @@
> +/*
> + * 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/delay.h>
> +#include <linux/err.h>
> +#include <linux/firmware.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <asm/unaligned.h>
> +#include <drm/drm_panel.h>
> +
> +#include <drmP.h>
> +#include <drm_atomic_helper.h>
> +#include <drm_crtc_helper.h>
> +#include <drm_crtc.h>
> +#include <drm_mipi_dsi.h>
> +
> +#define PAGE2_SPI_CFG3         0x82
> +#define I2C_TO_SPI_RESET       0x20
> +#define PAGE2_ROMADD_BYTE1     0x8e
> +#define PAGE2_ROMADD_BYTE2     0x8f
> +#define PAGE2_SWSPI_WDATA      0x90
> +#define PAGE2_SWSPI_RDATA      0x91
> +#define PAGE2_SWSPI_LEN                0x92
> +#define PAGE2_SWSPI_CTL                0x93
> +#define TRIGGER_NO_READBACK    0x05
> +#define TRIGGER_READBACK       0x01
> +#define PAGE2_SPI_STATUS       0x9e
> +#define PAGE2_GPIO_L           0xa6
> +#define PAGE2_GPIO_H           0xa7
> +#define PS_GPIO9               BIT(1)
> +#define PAGE2_IROM_CTRL                0xb0
> +#define IROM_ENABLE            0xc0
> +#define IROM_DISABLE           0x80
> +#define PAGE2_SW_REST          0xbc
> +#define PAGE2_ENCTLSPI_WR      0xda
> +#define PAGE2_I2C_BYPASS       0xea
> +#define I2C_BYPASS_EN          0xd0
> +
> +#define PAGE3_SET_ADD          0xfe
> +#define PAGE3_SET_VAL          0xff
> +#define VDO_CTL_ADD            0x13
> +#define VDO_DIS                        0x18
> +#define VDO_EN                 0x1c
> +
> +#define PAGE4_REV_L            0xf0
> +#define PAGE4_REV_H            0xf1
> +#define PAGE4_CHIP_L           0xf2
> +#define PAGE4_CHIP_H           0xf3
> +
> +/* Firmware */
> +#define SPI_MAX_RETRY_CNT      8
> +#define PS_FW_NAME             "ps864x_fw.bin"
> +
> +#define FW_CHIP_ID_OFFSET      0
> +#define FW_VERSION_OFFSET      2
> +
> +#define bridge_to_ps8640(e)    container_of(e, struct ps8640, bridge)
> +#define connector_to_ps8640(e) container_of(e, struct ps8640, connector)
> +
> +struct ps8640_info {
> +       u8 family_id;
> +       u8 variant_id;
> +       u16 version;
> +};
> +
> +struct ps8640 {
> +       struct drm_connector connector;
> +       struct drm_bridge bridge;
> +       struct mipi_dsi_device *dsi;
> +       struct i2c_client *page[8];
> +       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;
> +       bool enabled;
> +
> +       /* firmware file name */
> +       bool in_fw_update;
> +       char *fw_file;
> +       struct ps8640_info info;
> +};
> +
> +static const u8 enc_ctrl_code[6] = {0xaa, 0x55, 0x50, 0x41, 0x52, 0x44};
> +
> +static int ps8640_regr(struct i2c_client *client, u8 reg, u8 *data,
> +                      u16 data_len)

IMHO, ps8640_read() and ps8640_write() are clearer than regr and regw.

> +{
> +       int ret;
> +       struct i2c_msg msgs[] = {
> +               {
> +                .addr = client->addr,
> +                .flags = 0,
> +                .len = 1,
> +                .buf = &reg,
> +                },
> +               {
> +                .addr = client->addr,
> +                .flags = I2C_M_RD,
> +                .len = data_len,
> +                .buf = data,
> +                }
> +       };
> +
> +       ret = i2c_transfer(client->adapter, msgs, 2);
> +
> +       if (ret == 2)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_regw_bytes(struct i2c_client *client, u8 *data,
> +                            u16 data_len)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = data_len;
> +       msg.buf = data;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_regw_byte(struct i2c_client *client, u8 reg,  u8 data)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +       u8 buf[] = {reg, data};
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = sizeof(buf);
> +       msg.buf = buf;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[5];
> +       u8 fw_ver[2];
> +
> +       ps8640_regr(client, 0x4, fw_ver, 2);
> +       ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
> +
> +       DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
> +}
> +
> +static int ps8640_bridge_enable(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[3];
> +       int ret;
> +       u8 vdo_ctrl_buf[3] = {PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN};
> +
> +       ret = ps8640_regw_bytes(client, vdo_ctrl_buf, 3);
> +       return ret;

nit:  Just:

   return ps8640_regw_bytes(client, vdo_ctrl_buf, 3);

> +}
> +
> +static void ps8640_pre_enable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       struct i2c_client *client = ps_bridge->page[2];
> +       int err, retry_cnt = 0;
> +       u8 set_vdo_done;
> +
> +       if (ps_bridge->in_fw_update)
> +               return;
> +
> +       if (ps_bridge->enabled)
> +               return;
> +
> +       err = drm_panel_prepare(ps_bridge->panel);
> +       if (err < 0) {
> +               DRM_ERROR("failed to prepare panel: %d\n", err);
> +               return;
> +       }
> +
> +       gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> +
> +       err = regulator_enable(ps_bridge->pwr_1v2_supply);
> +       if (err < 0) {
> +               DRM_ERROR("failed to enable vdd12-supply: %d\n", err);
> +               goto err_panel_unprepare;
> +       }
> +
> +       err = regulator_enable(ps_bridge->pwr_3v3_supply);
> +       if (err < 0) {
> +               DRM_ERROR("failed to enable vdd33-supply: %d\n", err);
> +               goto err_regulator_1v2_disable;
> +       }
> +
> +       usleep_range(500, 700);
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> +
> +       /*
> +        * Wait for the ps8640 embed mcu ready
> +        * First wait 200ms and then check the mcu ready flag every 20ms
> +        */
> +       msleep(200);
> +       do {
> +               err = ps8640_regr(client, PAGE2_GPIO_H, &set_vdo_done, 1);
> +               if (err < 0) {
> +                       DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
> +                       goto err_regulator_1v2_disable;
> +               }
> +               msleep(20);
> +       } while ((retry_cnt++ < 10) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> +
> +       if (ps_bridge->info.version == 0)
> +               ps8640_get_mcu_fw_version(ps_bridge);
> +       /* Switch access edp panel's edid through i2c */
> +       ps8640_regw_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
> +       ps_bridge->enabled = true;
> +
> +       return;
> +
> +err_regulator_1v2_disable:
> +       regulator_disable(ps_bridge->pwr_1v2_supply);
> +err_panel_unprepare:
> +       drm_panel_unprepare(ps_bridge->panel);
> +}
> +
> +static void ps8640_enable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       err = ps8640_bridge_enable(ps_bridge);
> +       if (err)
> +               DRM_ERROR("failed to enable unmutevideo: %d\n", err);
> +
> +       err = drm_panel_enable(ps_bridge->panel);
> +       if (err < 0)
> +               DRM_ERROR("failed to enable panel: %d\n", err);
> +}
> +
> +static void ps8640_disable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       err = drm_panel_disable(ps_bridge->panel);
> +       if (err < 0)
> +               DRM_ERROR("failed to disable panel: %d\n", err);

Should there be a ps8640_bridge_disable() here, to undo ps8640_bridge_enable()?

> +}
> +
> +static void ps8640_post_disable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       if (ps_bridge->in_fw_update)
> +               return;
> +
> +       if (!ps_bridge->enabled)
> +               return;
> +
> +       ps_bridge->enabled = false;
> +
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> +       gpiod_set_value(ps_bridge->gpio_slp_n, 0);
> +       regulator_disable(ps_bridge->pwr_3v3_supply);
> +       regulator_disable(ps_bridge->pwr_1v2_supply);
> +
> +       err = drm_panel_unprepare(ps_bridge->panel);
> +       if (err)
> +               DRM_ERROR("failed to unprepare panel: %d\n", err);
> +}
> +
> +static int ps8640_get_modes(struct drm_connector *connector)
> +{
> +       struct ps8640 *ps_bridge = connector_to_ps8640(connector);
> +       bool power_off;
> +       int num_modes = 0;
> +
> +       power_off = !ps_bridge->enabled;
> +       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +       num_modes = drm_panel_get_modes(ps_bridge->panel);
> +
> +       if (power_off)
> +               ps8640_post_disable(&ps_bridge->bridge);
> +
> +       return num_modes;
> +}
> +
> +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);
> +       struct device *dev = &ps_bridge->page[0]->dev;
> +       struct device_node *np = dev->of_node;
> +       struct device_node *port, *in_ep;
> +       struct device_node *dsi_node = NULL;
> +       struct mipi_dsi_host *host = ps_bridge->dsi->host;
> +       int ret;
> +
> +       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: %d\n", ret);
> +               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);
> +
> +       /* port@0 is ps8640 dsi input port */
> +       port = of_graph_get_port_by_id(np, 0);
> +       if (port) {
> +               in_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               if (in_ep) {
> +                       dsi_node = of_graph_get_remote_port_parent(in_ep);
> +                       of_node_put(in_ep);
> +               }
> +       }
> +       if (dsi_node) {
> +               host = of_find_mipi_dsi_host_by_node(dsi_node);
> +               of_node_put(dsi_node);
> +               if (!host)
> +                       return -ENODEV;
> +       }
> +
> +       ps_bridge->dsi->host = host;
> +       ps_bridge->dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
> +                                    MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
> +       ps_bridge->dsi->format = MIPI_DSI_FMT_RGB888;
> +       ps_bridge->dsi->lanes = 4;
> +       ret = mipi_dsi_attach(ps_bridge->dsi);
> +       if (ret) {
> +               drm_panel_detach(ps_bridge->panel);
> +               return ret;
> +       }
> +
> +       return ret;
> +}
> +
> +static const struct drm_bridge_funcs ps8640_bridge_funcs = {
> +       .attach = ps8640_bridge_attach,
> +       .disable = ps8640_disable,
> +       .post_disable = ps8640_post_disable,
> +       .pre_enable = ps8640_pre_enable,
> +       .enable = ps8640_enable,
> +};
> +
> +static ssize_t ps8640_fw_file_show(struct device *dev,
> +                                  struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +
> +       return scnprintf(buf, PAGE_SIZE, "%s\n", ps_bridge->fw_file);
> +}
> +
> +static int ps8640_update_file_name(struct device *dev, char **file_name,
> +                                  const char *buf, size_t count)

Just remove this function now since fw_file is always just PS_FW_NAME.

> +{
> +       char *new_file_name;
> +
> +       /* Simple sanity check */
> +       if (count > 64) {
> +               dev_warn(dev, "File name too long\n");
> +               return -EINVAL;
> +       }
> +
> +       new_file_name = devm_kmalloc(dev, count + 1, GFP_KERNEL);
> +       if (!new_file_name)
> +               return -ENOMEM;
> +
> +       memcpy(new_file_name, buf, count + 1);
> +
> +       /* Echo into the sysfs entry may append newline at the end of buf */
> +       if (new_file_name[count - 1] == '\n')
> +               count--;
> +
> +       new_file_name[count] = '\0';
> +
> +       if (*file_name)
> +               devm_kfree(dev, *file_name);
> +
> +       *file_name = new_file_name;
> +
> +       return 0;
> +}
> +
> +/* Firmware Version is returned as Major.Minor.Build */
> +static ssize_t ps8640_fw_version_show(struct device *dev,
> +                                     struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +       struct ps8640_info *info = &ps_bridge->info;
> +
> +       return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
> +                        info->version & 0xff);

Just remove this sysfs entry since fw_file is always just PS_FW_NAME.

> +}
> +
> +/* Hardware Version is returned as FamilyID.VariantID */
> +static ssize_t ps8640_hw_version_show(struct device *dev,
> +                                     struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +       struct ps8640_info *info = &ps_bridge->info;
> +
> +       return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
> +                        info->variant_id);
> +}
> +
> +static int ps8640_spi_send_cmd(struct ps8640 *ps_bridge, u8 *cmd, u8 cmd_len)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 i;
> +       int ret;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto err;
> +
> +       /* write command in write port */
> +       for (i = 0; i < cmd_len; i++) {
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
> +               if (ret)
> +                       goto err;
> +       }
> +       /* command length */
> +       ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, cmd_len - 1);
> +       if (ret)
> +               goto err;
> +       /* trigger read */
> +       ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL, TRIGGER_NO_READBACK);
> +       if (ret)
> +               goto err;

nit: you can probably combine the write of PAGE2_SWSPI_LEN &
PAGE2_SWSPI_CTL into a single i2c transaction, here and in
ps8640_wait_spi_nobusy().

> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto err;
> +
> +       return 0;
> +
> +err:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_wait_spi_ready(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_rdy_st, retry_cnt = 0;
> +
> +       do {
> +               ps8640_regr(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
> +               msleep(20);
> +               if ((retry_cnt == SPI_MAX_RETRY_CNT) &&
> +                   ((spi_rdy_st & 0x0c) != 0x0c)) {
> +                       dev_err(&client->dev, "wait spi ready timeout\n");
> +                       return -EBUSY;
> +               }
> +       } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
> +                (spi_rdy_st & 0x0c) == 0x0c);
> +
> +       return 0;
> +}
> +
> +static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_status, retry_cnt = 0;
> +       int ret;
> +
> +       do {
> +               /* 0x05 RDSR; Read-Status-Register */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, 0x05);

Please #define this constant 0x05.


> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* command length */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, 0x00);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* trigger read */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL,
> +                                      TRIGGER_READBACK);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* delay for cmd send */
> +               usleep_range(100, 300);
> +               /* wait for SPI ROM until not busy */
> +               ret = ps8640_regr(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +       } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
> +                (spi_status & 0x0c) == 0x0c);
> +
> +       if ((retry_cnt > SPI_MAX_RETRY_CNT) && (spi_status & 0x0c) != 0x0c) {

Please #define this constant 0x0c.


> +               ret = -EBUSY;
> +               dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
> +               goto err_timeout;
> +       }
> +
> +       return 0;
> +
> +err_send_cmd_exit:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +
> +err_timeout:
> +       return ret;
> +}
> +
> +static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       int ret;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_ready(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_nobusy(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto exit;
> +
> +exit:
> +       if (ret)
> +               dev_err(&client->dev, "wait ps8640 rom idle fail: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ps8640_spi_dl_mode(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       int ret;
> +
> +       /* switch ps8640 mode to spi dl mode */
> +       gpiod_set_value(ps_bridge->gpio_mode_sel_n, 0);
> +
> +       /* reset spi interface */
> +       ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0xc0);

Please #define these constants, 0xc0 & 0x40.  Is this a bit field?

> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0x40);
> +       if (ret)
> +               goto exit;
> +
> +exit:
> +       if (ret)
> +               dev_err(&client->dev, "fail reset spi interface: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ps8640_rom_prepare(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       struct device *dev = &client->dev;
> +       u8 i, cmd[2];
> +       int ret;
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;

Please #define magic numbers / constants in this function.


> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "failed enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* disable all protection */
> +       cmd[0] = 0x01;
> +       cmd[1] = 0x00;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +       if (ret) {
> +               dev_err(dev, "fail disable all protection: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* wait for SPI module ready */
> +       ret = ps8640_wait_rom_idle(ps_bridge);
> +       if (ret) {
> +               dev_err(dev, "fail wait rom idle: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       for (i = 0; i < 6; i++)
> +               ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
> +       ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "fail enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* chip erase command */
> +       cmd[0] = 0xc7;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "fail disable all protection: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ret = ps8640_wait_rom_idle(ps_bridge);
> +       if (ret) {
> +               dev_err(dev, "fail wait rom idle: %d\n", ret);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
> +                                   const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct ps8640_info *info = &ps_bridge->info;
> +       u16 fw_chip_id, fw_version_id;
> +
> +       /*
> +        * Get the chip_id from the firmware. Make sure that it is the
> +        * right controller to do the firmware and config update.
> +        */
> +       fw_chip_id = get_unaligned_le16(fw->data + FW_CHIP_ID_OFFSET);
> +
> +       if (fw_chip_id != 0x8640) {
> +               dev_err(&client->dev,
> +                       "chip id mismatch: fw 0x%x vs. chip 0x8640\n",
> +                       fw_chip_id);
> +               return -ENODEV;
> +       }
> +
> +       fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
> +
> +       if (fw_chip_id != info->version) {
> +               dev_err(&client->dev,
> +                       "fw version mismatch: fw %d.%d vs. chip %d.%d\n",
> +                       fw_version_id >> 8, fw_version_id & 0xff,
> +                       info->version >> 8, info->version & 0xff);
> +               return -ENODEV;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_write_rom(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct device *dev = &client->dev;
> +       struct i2c_client *client2 = ps_bridge->page[2];
> +       struct i2c_client *client7 = ps_bridge->page[7];
> +       unsigned int pos = 0;
> +       u8 buf[257], rom_page_id_buf[3];
> +       int ret;
> +       u16 cpy_len;
> +
> +       ps8640_regw_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
> +       msleep(100);
> +       ps8640_regw_byte(client2, PAGE2_SPI_CFG3, 0x00);
> +
> +       while (pos < fw->size) {
> +               rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
> +               rom_page_id_buf[1] = (pos >> 8) & 0xff;
> +               rom_page_id_buf[2] = (pos >> 16) & 0xff;
> +               ret = ps8640_regw_bytes(client2, rom_page_id_buf, 3);
> +               if (ret)
> +                       goto error;
> +               cpy_len = fw->size >= 256 + pos ? 256 : fw->size - pos;
> +               buf[0] = 0;
> +               memcpy(buf + 1, fw->data + pos, cpy_len);
> +               ret = ps8640_regw_bytes(client7, buf, cpy_len + 1);
> +               if (ret)
> +                       goto error;
> +
> +               pos += cpy_len;
> +
> +               dev_dbg(dev, "fw update completed %u / %zu bytes\n", pos,
> +                       fw->size);
> +       }
> +       return 0;
> +
> +error:
> +       dev_err(dev, "failed write extenal flash, %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_spi_normal_mode(struct ps8640 *ps_bridge)
> +{
> +       u8 cmd[2];
> +       struct i2c_client *client = ps_bridge->page[2];

Please #define magic numbers / constants in this function.

> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +
> +       /* protect BPL/BP0/BP1 */
> +       cmd[0] = 0x01;
> +       cmd[1] = 0x8c;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +
> +       /* wait for SPI rom ready */
> +       ps8640_wait_rom_idle(ps_bridge);
> +
> +       /* disable PS8640 mapping function */
> +       ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
> +
> +       gpiod_set_value(ps_bridge->gpio_mode_sel_n, 1);
> +       return 0;
> +}
> +
> +static int ps8640_enter_bl(struct ps8640 *ps_bridge)
> +{
> +       int ret;
> +
> +       ret = ps8640_spi_dl_mode(ps_bridge);
> +       if (ret)
> +               return ret;
> +
> +       ps_bridge->in_fw_update = true;

Set in_fw_update before ps8640_spi_dl_mode() to avoid a race between
between ps8640_spi_dl_mode() and ps8640_pre_enable / post_disable().

> +       return 0;
> +}
> +
> +static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       ps_bridge->in_fw_update = false;
> +       ps8640_spi_normal_mode(ps_bridge);

Set in_fw_update after ps8640_spi_normal_mode() to avoid a race
between between ps8640_spi_normal_mode() and ps8640_pre_enable /
post_disable().

> +}
> +
> +static int ps8640_load_fw(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct device *dev = &client->dev;
> +       int ret;
> +       bool ps8640_status_backup = ps_bridge->enabled;
> +
> +       if (!ps_bridge->in_fw_update) {
> +               if (!ps8640_status_backup)
> +                       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +               ret = ps8640_enter_bl(ps_bridge);
> +               if (ret)
> +                       goto exit;
> +       }
> +
> +       ret = ps8640_validate_firmware(ps_bridge, fw);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_rom_prepare(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_write_rom(ps_bridge, fw);
> +
> +exit:
> +       if (ret)
> +               dev_err(dev, "Failed to load firmware, %d\n", ret);
> +
> +       ps8640_exit_bl(ps_bridge, fw);
> +       if (!ps8640_status_backup)
> +               ps8640_post_disable(&ps_bridge->bridge);
> +       return ret;
> +}
> +
> +static ssize_t ps8640_update_fw_store(struct device *dev,
> +                                     struct device_attribute *attr,
> +                                     const char *buf, size_t count)
> +{
> +       struct i2c_client *client = to_i2c_client(dev);
> +       struct ps8640 *ps_bridge = i2c_get_clientdata(client);
> +       const struct firmware *fw;
> +       int error;
> +
> +       error = request_firmware(&fw, ps_bridge->fw_file, dev);
> +       if (error) {
> +               dev_err(dev, "Unable to open firmware %s: %d\n",
> +                       ps_bridge->fw_file, error);
> +               return error;
> +       }
> +
> +       error = ps8640_load_fw(ps_bridge, fw);
> +       if (error)
> +               dev_err(dev, "The firmware update failed(%d)\n", error);
> +       else
> +               dev_info(dev, "The firmware update succeeded\n");
> +
> +       release_firmware(fw);
> +       return error ? error : count;
> +}
> +
> +static DEVICE_ATTR(fw_file, S_IRUGO, ps8640_fw_file_show, NULL);
> +static DEVICE_ATTR(fw_version, S_IRUGO, ps8640_fw_version_show, NULL);
> +static DEVICE_ATTR(hw_version, S_IRUGO, ps8640_hw_version_show, NULL);
> +static DEVICE_ATTR(update_fw, S_IWUSR, NULL, ps8640_update_fw_store);
> +
> +static struct attribute *ps8640_attrs[] = {
> +       &dev_attr_fw_file.attr,
> +       &dev_attr_fw_version.attr,
> +       &dev_attr_hw_version.attr,
> +       &dev_attr_update_fw.attr,
> +       NULL
> +};
> +
> +static const struct attribute_group ps8640_attr_group = {
> +       .attrs = ps8640_attrs,
> +};
> +
> +static void ps8640_remove_sysfs_group(void *data)
> +{
> +       struct ps8640 *ps_bridge = data;
> +
> +       sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
> +}
> +
> +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 *port, *out_ep;
> +       struct device_node *panel_node = NULL;
> +       int i, ret;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
> +                                     GFP_KERNEL);
> +       if (!ps_bridge) {
> +               ret = -ENOMEM;
> +               goto exit;

nit: instead of "goto exit", you can just:

  return -ENOMEM; (for all of these "goto exit")

> +       }
> +       /* port@1 is ps8640 output port */
> +       port = of_graph_get_port_by_id(np, 1);
> +       if (port) {
> +               out_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               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) {
> +                       ret = -EPROBE_DEFER;
> +                       goto exit;
> +               }
> +       }
> +
> +       ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
> +       if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
> +               dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");
> +       if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_1v2_supply);
> +               dev_err(dev, "cannot get vdd12 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       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);
> +               dev_err(dev, "cannot get gpio_mode_sel_n %d\n", ret);

nit: I'd use the gpio's device tree name in the error message here, so
"mode-sel".
Same for the others, below.

  dev_err(dev, "cannot get gpio 'mode-sel' %d\n", ret);

Thanks,
-Dan

Re: [PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Daniel Kurtz]

On Mon, Feb 1, 2016 at 12:13 PM, Jitao Shi <jitao.shi@mediatek.com> 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 v7:
>  - Change ps8640_regw to ps8640_regw_bytes and remove devm_kzalloc
>  - Fine tune ps8640 power squence
>  - Add ps8640_pre_enable and ps8640_post_disable in ps8640_get_modes
>  - Remove unnecessary codes and comments
>
> The following patches are needed to support dsi host through none dsi bus:
>
> https://patchwork.kernel.org/patch/7818431/ ("drm/dsi: check for CONFIG_OF when defining of_mipi_dsi_device_add")
> https://patchwork.kernel.org/patch/7818471/ ("drm/dsi: Refactor device creation")
> https://patchwork.kernel.org/patch/7818501/ ("drm/dsi: Try to match non-DT dsi devices")
> https://patchwork.kernel.org/patch/7818531/ ("drm/dsi: Check for used channels")
> https://patchwork.kernel.org/patch/7818561/ ("drm/dsi: Add routine to unregister dsi device")
> https://patchwork.kernel.org/patch/7818541/ ("drm/dsi: Get DSI host by DT device node")
> ---
>  drivers/gpu/drm/bridge/Kconfig         |   10 +
>  drivers/gpu/drm/bridge/Makefile        |    1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c | 1084 ++++++++++++++++++++++++++++++++
>  3 files changed, 1095 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 27e2022..fe8ad50 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -40,4 +40,14 @@ config DRM_PARADE_PS8622
>         ---help---
>           Parade eDP-LVDS bridge chip driver.
>
> +config DRM_PARADE_PS8640
> +       tristate "Parade PS8640 MIPI DSI to eDP Converter"
> +       depends on OF && I2C
> +       select DRM_KMS_HELPER

I think this needs:

select DRM_MIPI_DSI

Otherwise:
drivers/gpu/drm/bridge/parade-ps8640.c:400: undefined reference to
`of_find_mipi_dsi_host_by_node'
drivers/gpu/drm/bridge/parade-ps8640.c:411: undefined reference to
`mipi_dsi_attach'

> +       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 f13c33d..fbe38dc 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.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..0230ab5
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,1084 @@
> +/*
> + * 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/delay.h>
> +#include <linux/err.h>
> +#include <linux/firmware.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <asm/unaligned.h>
> +#include <drm/drm_panel.h>
> +
> +#include <drmP.h>
> +#include <drm_atomic_helper.h>
> +#include <drm_crtc_helper.h>
> +#include <drm_crtc.h>
> +#include <drm_mipi_dsi.h>
> +
> +#define PAGE2_SPI_CFG3         0x82
> +#define I2C_TO_SPI_RESET       0x20
> +#define PAGE2_ROMADD_BYTE1     0x8e
> +#define PAGE2_ROMADD_BYTE2     0x8f
> +#define PAGE2_SWSPI_WDATA      0x90
> +#define PAGE2_SWSPI_RDATA      0x91
> +#define PAGE2_SWSPI_LEN                0x92
> +#define PAGE2_SWSPI_CTL                0x93
> +#define TRIGGER_NO_READBACK    0x05
> +#define TRIGGER_READBACK       0x01
> +#define PAGE2_SPI_STATUS       0x9e
> +#define PAGE2_GPIO_L           0xa6
> +#define PAGE2_GPIO_H           0xa7
> +#define PS_GPIO9               BIT(1)
> +#define PAGE2_IROM_CTRL                0xb0
> +#define IROM_ENABLE            0xc0
> +#define IROM_DISABLE           0x80
> +#define PAGE2_SW_REST          0xbc
> +#define PAGE2_ENCTLSPI_WR      0xda
> +#define PAGE2_I2C_BYPASS       0xea
> +#define I2C_BYPASS_EN          0xd0
> +
> +#define PAGE3_SET_ADD          0xfe
> +#define PAGE3_SET_VAL          0xff
> +#define VDO_CTL_ADD            0x13
> +#define VDO_DIS                        0x18
> +#define VDO_EN                 0x1c
> +
> +#define PAGE4_REV_L            0xf0
> +#define PAGE4_REV_H            0xf1
> +#define PAGE4_CHIP_L           0xf2
> +#define PAGE4_CHIP_H           0xf3
> +
> +/* Firmware */
> +#define SPI_MAX_RETRY_CNT      8
> +#define PS_FW_NAME             "ps864x_fw.bin"
> +
> +#define FW_CHIP_ID_OFFSET      0
> +#define FW_VERSION_OFFSET      2
> +
> +#define bridge_to_ps8640(e)    container_of(e, struct ps8640, bridge)
> +#define connector_to_ps8640(e) container_of(e, struct ps8640, connector)
> +
> +struct ps8640_info {
> +       u8 family_id;
> +       u8 variant_id;
> +       u16 version;
> +};
> +
> +struct ps8640 {
> +       struct drm_connector connector;
> +       struct drm_bridge bridge;
> +       struct mipi_dsi_device *dsi;
> +       struct i2c_client *page[8];
> +       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;
> +       bool enabled;
> +
> +       /* firmware file name */
> +       bool in_fw_update;
> +       char *fw_file;
> +       struct ps8640_info info;
> +};
> +
> +static const u8 enc_ctrl_code[6] = {0xaa, 0x55, 0x50, 0x41, 0x52, 0x44};
> +
> +static int ps8640_regr(struct i2c_client *client, u8 reg, u8 *data,
> +                      u16 data_len)

IMHO, ps8640_read() and ps8640_write() are clearer than regr and regw.

> +{
> +       int ret;
> +       struct i2c_msg msgs[] = {
> +               {
> +                .addr = client->addr,
> +                .flags = 0,
> +                .len = 1,
> +                .buf = &reg,
> +                },
> +               {
> +                .addr = client->addr,
> +                .flags = I2C_M_RD,
> +                .len = data_len,
> +                .buf = data,
> +                }
> +       };
> +
> +       ret = i2c_transfer(client->adapter, msgs, 2);
> +
> +       if (ret == 2)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_regw_bytes(struct i2c_client *client, u8 *data,
> +                            u16 data_len)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = data_len;
> +       msg.buf = data;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_regw_byte(struct i2c_client *client, u8 reg,  u8 data)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +       u8 buf[] = {reg, data};
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = sizeof(buf);
> +       msg.buf = buf;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[5];
> +       u8 fw_ver[2];
> +
> +       ps8640_regr(client, 0x4, fw_ver, 2);
> +       ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
> +
> +       DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
> +}
> +
> +static int ps8640_bridge_enable(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[3];
> +       int ret;
> +       u8 vdo_ctrl_buf[3] = {PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN};
> +
> +       ret = ps8640_regw_bytes(client, vdo_ctrl_buf, 3);
> +       return ret;

nit:  Just:

   return ps8640_regw_bytes(client, vdo_ctrl_buf, 3);

> +}
> +
> +static void ps8640_pre_enable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       struct i2c_client *client = ps_bridge->page[2];
> +       int err, retry_cnt = 0;
> +       u8 set_vdo_done;
> +
> +       if (ps_bridge->in_fw_update)
> +               return;
> +
> +       if (ps_bridge->enabled)
> +               return;
> +
> +       err = drm_panel_prepare(ps_bridge->panel);
> +       if (err < 0) {
> +               DRM_ERROR("failed to prepare panel: %d\n", err);
> +               return;
> +       }
> +
> +       gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> +
> +       err = regulator_enable(ps_bridge->pwr_1v2_supply);
> +       if (err < 0) {
> +               DRM_ERROR("failed to enable vdd12-supply: %d\n", err);
> +               goto err_panel_unprepare;
> +       }
> +
> +       err = regulator_enable(ps_bridge->pwr_3v3_supply);
> +       if (err < 0) {
> +               DRM_ERROR("failed to enable vdd33-supply: %d\n", err);
> +               goto err_regulator_1v2_disable;
> +       }
> +
> +       usleep_range(500, 700);
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> +
> +       /*
> +        * Wait for the ps8640 embed mcu ready
> +        * First wait 200ms and then check the mcu ready flag every 20ms
> +        */
> +       msleep(200);
> +       do {
> +               err = ps8640_regr(client, PAGE2_GPIO_H, &set_vdo_done, 1);
> +               if (err < 0) {
> +                       DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
> +                       goto err_regulator_1v2_disable;
> +               }
> +               msleep(20);
> +       } while ((retry_cnt++ < 10) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> +
> +       if (ps_bridge->info.version == 0)
> +               ps8640_get_mcu_fw_version(ps_bridge);
> +       /* Switch access edp panel's edid through i2c */
> +       ps8640_regw_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
> +       ps_bridge->enabled = true;
> +
> +       return;
> +
> +err_regulator_1v2_disable:
> +       regulator_disable(ps_bridge->pwr_1v2_supply);
> +err_panel_unprepare:
> +       drm_panel_unprepare(ps_bridge->panel);
> +}
> +
> +static void ps8640_enable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       err = ps8640_bridge_enable(ps_bridge);
> +       if (err)
> +               DRM_ERROR("failed to enable unmutevideo: %d\n", err);
> +
> +       err = drm_panel_enable(ps_bridge->panel);
> +       if (err < 0)
> +               DRM_ERROR("failed to enable panel: %d\n", err);
> +}
> +
> +static void ps8640_disable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       err = drm_panel_disable(ps_bridge->panel);
> +       if (err < 0)
> +               DRM_ERROR("failed to disable panel: %d\n", err);

Should there be a ps8640_bridge_disable() here, to undo ps8640_bridge_enable()?

> +}
> +
> +static void ps8640_post_disable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       if (ps_bridge->in_fw_update)
> +               return;
> +
> +       if (!ps_bridge->enabled)
> +               return;
> +
> +       ps_bridge->enabled = false;
> +
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> +       gpiod_set_value(ps_bridge->gpio_slp_n, 0);
> +       regulator_disable(ps_bridge->pwr_3v3_supply);
> +       regulator_disable(ps_bridge->pwr_1v2_supply);
> +
> +       err = drm_panel_unprepare(ps_bridge->panel);
> +       if (err)
> +               DRM_ERROR("failed to unprepare panel: %d\n", err);
> +}
> +
> +static int ps8640_get_modes(struct drm_connector *connector)
> +{
> +       struct ps8640 *ps_bridge = connector_to_ps8640(connector);
> +       bool power_off;
> +       int num_modes = 0;
> +
> +       power_off = !ps_bridge->enabled;
> +       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +       num_modes = drm_panel_get_modes(ps_bridge->panel);
> +
> +       if (power_off)
> +               ps8640_post_disable(&ps_bridge->bridge);
> +
> +       return num_modes;
> +}
> +
> +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);
> +       struct device *dev = &ps_bridge->page[0]->dev;
> +       struct device_node *np = dev->of_node;
> +       struct device_node *port, *in_ep;
> +       struct device_node *dsi_node = NULL;
> +       struct mipi_dsi_host *host = ps_bridge->dsi->host;
> +       int ret;
> +
> +       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: %d\n", ret);
> +               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);
> +
> +       /* port@0 is ps8640 dsi input port */
> +       port = of_graph_get_port_by_id(np, 0);
> +       if (port) {
> +               in_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               if (in_ep) {
> +                       dsi_node = of_graph_get_remote_port_parent(in_ep);
> +                       of_node_put(in_ep);
> +               }
> +       }
> +       if (dsi_node) {
> +               host = of_find_mipi_dsi_host_by_node(dsi_node);
> +               of_node_put(dsi_node);
> +               if (!host)
> +                       return -ENODEV;
> +       }
> +
> +       ps_bridge->dsi->host = host;
> +       ps_bridge->dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
> +                                    MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
> +       ps_bridge->dsi->format = MIPI_DSI_FMT_RGB888;
> +       ps_bridge->dsi->lanes = 4;
> +       ret = mipi_dsi_attach(ps_bridge->dsi);
> +       if (ret) {
> +               drm_panel_detach(ps_bridge->panel);
> +               return ret;
> +       }
> +
> +       return ret;
> +}
> +
> +static const struct drm_bridge_funcs ps8640_bridge_funcs = {
> +       .attach = ps8640_bridge_attach,
> +       .disable = ps8640_disable,
> +       .post_disable = ps8640_post_disable,
> +       .pre_enable = ps8640_pre_enable,
> +       .enable = ps8640_enable,
> +};
> +
> +static ssize_t ps8640_fw_file_show(struct device *dev,
> +                                  struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +
> +       return scnprintf(buf, PAGE_SIZE, "%s\n", ps_bridge->fw_file);
> +}
> +
> +static int ps8640_update_file_name(struct device *dev, char **file_name,
> +                                  const char *buf, size_t count)

Just remove this function now since fw_file is always just PS_FW_NAME.

> +{
> +       char *new_file_name;
> +
> +       /* Simple sanity check */
> +       if (count > 64) {
> +               dev_warn(dev, "File name too long\n");
> +               return -EINVAL;
> +       }
> +
> +       new_file_name = devm_kmalloc(dev, count + 1, GFP_KERNEL);
> +       if (!new_file_name)
> +               return -ENOMEM;
> +
> +       memcpy(new_file_name, buf, count + 1);
> +
> +       /* Echo into the sysfs entry may append newline at the end of buf */
> +       if (new_file_name[count - 1] == '\n')
> +               count--;
> +
> +       new_file_name[count] = '\0';
> +
> +       if (*file_name)
> +               devm_kfree(dev, *file_name);
> +
> +       *file_name = new_file_name;
> +
> +       return 0;
> +}
> +
> +/* Firmware Version is returned as Major.Minor.Build */
> +static ssize_t ps8640_fw_version_show(struct device *dev,
> +                                     struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +       struct ps8640_info *info = &ps_bridge->info;
> +
> +       return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
> +                        info->version & 0xff);

Just remove this sysfs entry since fw_file is always just PS_FW_NAME.

> +}
> +
> +/* Hardware Version is returned as FamilyID.VariantID */
> +static ssize_t ps8640_hw_version_show(struct device *dev,
> +                                     struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +       struct ps8640_info *info = &ps_bridge->info;
> +
> +       return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
> +                        info->variant_id);
> +}
> +
> +static int ps8640_spi_send_cmd(struct ps8640 *ps_bridge, u8 *cmd, u8 cmd_len)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 i;
> +       int ret;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto err;
> +
> +       /* write command in write port */
> +       for (i = 0; i < cmd_len; i++) {
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
> +               if (ret)
> +                       goto err;
> +       }
> +       /* command length */
> +       ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, cmd_len - 1);
> +       if (ret)
> +               goto err;
> +       /* trigger read */
> +       ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL, TRIGGER_NO_READBACK);
> +       if (ret)
> +               goto err;

nit: you can probably combine the write of PAGE2_SWSPI_LEN &
PAGE2_SWSPI_CTL into a single i2c transaction, here and in
ps8640_wait_spi_nobusy().

> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto err;
> +
> +       return 0;
> +
> +err:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_wait_spi_ready(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_rdy_st, retry_cnt = 0;
> +
> +       do {
> +               ps8640_regr(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
> +               msleep(20);
> +               if ((retry_cnt == SPI_MAX_RETRY_CNT) &&
> +                   ((spi_rdy_st & 0x0c) != 0x0c)) {
> +                       dev_err(&client->dev, "wait spi ready timeout\n");
> +                       return -EBUSY;
> +               }
> +       } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
> +                (spi_rdy_st & 0x0c) == 0x0c);
> +
> +       return 0;
> +}
> +
> +static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_status, retry_cnt = 0;
> +       int ret;
> +
> +       do {
> +               /* 0x05 RDSR; Read-Status-Register */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, 0x05);

Please #define this constant 0x05.


> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* command length */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, 0x00);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* trigger read */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL,
> +                                      TRIGGER_READBACK);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* delay for cmd send */
> +               usleep_range(100, 300);
> +               /* wait for SPI ROM until not busy */
> +               ret = ps8640_regr(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +       } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
> +                (spi_status & 0x0c) == 0x0c);
> +
> +       if ((retry_cnt > SPI_MAX_RETRY_CNT) && (spi_status & 0x0c) != 0x0c) {

Please #define this constant 0x0c.


> +               ret = -EBUSY;
> +               dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
> +               goto err_timeout;
> +       }
> +
> +       return 0;
> +
> +err_send_cmd_exit:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +
> +err_timeout:
> +       return ret;
> +}
> +
> +static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       int ret;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_ready(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_nobusy(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto exit;
> +
> +exit:
> +       if (ret)
> +               dev_err(&client->dev, "wait ps8640 rom idle fail: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ps8640_spi_dl_mode(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       int ret;
> +
> +       /* switch ps8640 mode to spi dl mode */
> +       gpiod_set_value(ps_bridge->gpio_mode_sel_n, 0);
> +
> +       /* reset spi interface */
> +       ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0xc0);

Please #define these constants, 0xc0 & 0x40.  Is this a bit field?

> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0x40);
> +       if (ret)
> +               goto exit;
> +
> +exit:
> +       if (ret)
> +               dev_err(&client->dev, "fail reset spi interface: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ps8640_rom_prepare(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       struct device *dev = &client->dev;
> +       u8 i, cmd[2];
> +       int ret;
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;

Please #define magic numbers / constants in this function.


> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "failed enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* disable all protection */
> +       cmd[0] = 0x01;
> +       cmd[1] = 0x00;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +       if (ret) {
> +               dev_err(dev, "fail disable all protection: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* wait for SPI module ready */
> +       ret = ps8640_wait_rom_idle(ps_bridge);
> +       if (ret) {
> +               dev_err(dev, "fail wait rom idle: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       for (i = 0; i < 6; i++)
> +               ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
> +       ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "fail enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* chip erase command */
> +       cmd[0] = 0xc7;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "fail disable all protection: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ret = ps8640_wait_rom_idle(ps_bridge);
> +       if (ret) {
> +               dev_err(dev, "fail wait rom idle: %d\n", ret);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
> +                                   const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct ps8640_info *info = &ps_bridge->info;
> +       u16 fw_chip_id, fw_version_id;
> +
> +       /*
> +        * Get the chip_id from the firmware. Make sure that it is the
> +        * right controller to do the firmware and config update.
> +        */
> +       fw_chip_id = get_unaligned_le16(fw->data + FW_CHIP_ID_OFFSET);
> +
> +       if (fw_chip_id != 0x8640) {
> +               dev_err(&client->dev,
> +                       "chip id mismatch: fw 0x%x vs. chip 0x8640\n",
> +                       fw_chip_id);
> +               return -ENODEV;
> +       }
> +
> +       fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
> +
> +       if (fw_chip_id != info->version) {
> +               dev_err(&client->dev,
> +                       "fw version mismatch: fw %d.%d vs. chip %d.%d\n",
> +                       fw_version_id >> 8, fw_version_id & 0xff,
> +                       info->version >> 8, info->version & 0xff);
> +               return -ENODEV;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_write_rom(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct device *dev = &client->dev;
> +       struct i2c_client *client2 = ps_bridge->page[2];
> +       struct i2c_client *client7 = ps_bridge->page[7];
> +       unsigned int pos = 0;
> +       u8 buf[257], rom_page_id_buf[3];
> +       int ret;
> +       u16 cpy_len;
> +
> +       ps8640_regw_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
> +       msleep(100);
> +       ps8640_regw_byte(client2, PAGE2_SPI_CFG3, 0x00);
> +
> +       while (pos < fw->size) {
> +               rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
> +               rom_page_id_buf[1] = (pos >> 8) & 0xff;
> +               rom_page_id_buf[2] = (pos >> 16) & 0xff;
> +               ret = ps8640_regw_bytes(client2, rom_page_id_buf, 3);
> +               if (ret)
> +                       goto error;
> +               cpy_len = fw->size >= 256 + pos ? 256 : fw->size - pos;
> +               buf[0] = 0;
> +               memcpy(buf + 1, fw->data + pos, cpy_len);
> +               ret = ps8640_regw_bytes(client7, buf, cpy_len + 1);
> +               if (ret)
> +                       goto error;
> +
> +               pos += cpy_len;
> +
> +               dev_dbg(dev, "fw update completed %u / %zu bytes\n", pos,
> +                       fw->size);
> +       }
> +       return 0;
> +
> +error:
> +       dev_err(dev, "failed write extenal flash, %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_spi_normal_mode(struct ps8640 *ps_bridge)
> +{
> +       u8 cmd[2];
> +       struct i2c_client *client = ps_bridge->page[2];

Please #define magic numbers / constants in this function.

> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +
> +       /* protect BPL/BP0/BP1 */
> +       cmd[0] = 0x01;
> +       cmd[1] = 0x8c;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +
> +       /* wait for SPI rom ready */
> +       ps8640_wait_rom_idle(ps_bridge);
> +
> +       /* disable PS8640 mapping function */
> +       ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
> +
> +       gpiod_set_value(ps_bridge->gpio_mode_sel_n, 1);
> +       return 0;
> +}
> +
> +static int ps8640_enter_bl(struct ps8640 *ps_bridge)
> +{
> +       int ret;
> +
> +       ret = ps8640_spi_dl_mode(ps_bridge);
> +       if (ret)
> +               return ret;
> +
> +       ps_bridge->in_fw_update = true;

Set in_fw_update before ps8640_spi_dl_mode() to avoid a race between
between ps8640_spi_dl_mode() and ps8640_pre_enable / post_disable().

> +       return 0;
> +}
> +
> +static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       ps_bridge->in_fw_update = false;
> +       ps8640_spi_normal_mode(ps_bridge);

Set in_fw_update after ps8640_spi_normal_mode() to avoid a race
between between ps8640_spi_normal_mode() and ps8640_pre_enable /
post_disable().

> +}
> +
> +static int ps8640_load_fw(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct device *dev = &client->dev;
> +       int ret;
> +       bool ps8640_status_backup = ps_bridge->enabled;
> +
> +       if (!ps_bridge->in_fw_update) {
> +               if (!ps8640_status_backup)
> +                       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +               ret = ps8640_enter_bl(ps_bridge);
> +               if (ret)
> +                       goto exit;
> +       }
> +
> +       ret = ps8640_validate_firmware(ps_bridge, fw);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_rom_prepare(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_write_rom(ps_bridge, fw);
> +
> +exit:
> +       if (ret)
> +               dev_err(dev, "Failed to load firmware, %d\n", ret);
> +
> +       ps8640_exit_bl(ps_bridge, fw);
> +       if (!ps8640_status_backup)
> +               ps8640_post_disable(&ps_bridge->bridge);
> +       return ret;
> +}
> +
> +static ssize_t ps8640_update_fw_store(struct device *dev,
> +                                     struct device_attribute *attr,
> +                                     const char *buf, size_t count)
> +{
> +       struct i2c_client *client = to_i2c_client(dev);
> +       struct ps8640 *ps_bridge = i2c_get_clientdata(client);
> +       const struct firmware *fw;
> +       int error;
> +
> +       error = request_firmware(&fw, ps_bridge->fw_file, dev);
> +       if (error) {
> +               dev_err(dev, "Unable to open firmware %s: %d\n",
> +                       ps_bridge->fw_file, error);
> +               return error;
> +       }
> +
> +       error = ps8640_load_fw(ps_bridge, fw);
> +       if (error)
> +               dev_err(dev, "The firmware update failed(%d)\n", error);
> +       else
> +               dev_info(dev, "The firmware update succeeded\n");
> +
> +       release_firmware(fw);
> +       return error ? error : count;
> +}
> +
> +static DEVICE_ATTR(fw_file, S_IRUGO, ps8640_fw_file_show, NULL);
> +static DEVICE_ATTR(fw_version, S_IRUGO, ps8640_fw_version_show, NULL);
> +static DEVICE_ATTR(hw_version, S_IRUGO, ps8640_hw_version_show, NULL);
> +static DEVICE_ATTR(update_fw, S_IWUSR, NULL, ps8640_update_fw_store);
> +
> +static struct attribute *ps8640_attrs[] = {
> +       &dev_attr_fw_file.attr,
> +       &dev_attr_fw_version.attr,
> +       &dev_attr_hw_version.attr,
> +       &dev_attr_update_fw.attr,
> +       NULL
> +};
> +
> +static const struct attribute_group ps8640_attr_group = {
> +       .attrs = ps8640_attrs,
> +};
> +
> +static void ps8640_remove_sysfs_group(void *data)
> +{
> +       struct ps8640 *ps_bridge = data;
> +
> +       sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
> +}
> +
> +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 *port, *out_ep;
> +       struct device_node *panel_node = NULL;
> +       int i, ret;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
> +                                     GFP_KERNEL);
> +       if (!ps_bridge) {
> +               ret = -ENOMEM;
> +               goto exit;

nit: instead of "goto exit", you can just:

  return -ENOMEM; (for all of these "goto exit")

> +       }
> +       /* port@1 is ps8640 output port */
> +       port = of_graph_get_port_by_id(np, 1);
> +       if (port) {
> +               out_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               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) {
> +                       ret = -EPROBE_DEFER;
> +                       goto exit;
> +               }
> +       }
> +
> +       ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
> +       if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
> +               dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");
> +       if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_1v2_supply);
> +               dev_err(dev, "cannot get vdd12 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       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);
> +               dev_err(dev, "cannot get gpio_mode_sel_n %d\n", ret);

nit: I'd use the gpio's device tree name in the error message here, so
"mode-sel".
Same for the others, below.

  dev_err(dev, "cannot get gpio 'mode-sel' %d\n", ret);

Thanks,
-Dan

[PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Daniel Kurtz]

On Mon, Feb 1, 2016 at 12:13 PM, Jitao Shi <jitao.shi@mediatek.com> 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 v7:
>  - Change ps8640_regw to ps8640_regw_bytes and remove devm_kzalloc
>  - Fine tune ps8640 power squence
>  - Add ps8640_pre_enable and ps8640_post_disable in ps8640_get_modes
>  - Remove unnecessary codes and comments
>
> The following patches are needed to support dsi host through none dsi bus:
>
> https://patchwork.kernel.org/patch/7818431/ ("drm/dsi: check for CONFIG_OF when defining of_mipi_dsi_device_add")
> https://patchwork.kernel.org/patch/7818471/ ("drm/dsi: Refactor device creation")
> https://patchwork.kernel.org/patch/7818501/ ("drm/dsi: Try to match non-DT dsi devices")
> https://patchwork.kernel.org/patch/7818531/ ("drm/dsi: Check for used channels")
> https://patchwork.kernel.org/patch/7818561/ ("drm/dsi: Add routine to unregister dsi device")
> https://patchwork.kernel.org/patch/7818541/ ("drm/dsi: Get DSI host by DT device node")
> ---
>  drivers/gpu/drm/bridge/Kconfig         |   10 +
>  drivers/gpu/drm/bridge/Makefile        |    1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c | 1084 ++++++++++++++++++++++++++++++++
>  3 files changed, 1095 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 27e2022..fe8ad50 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -40,4 +40,14 @@ config DRM_PARADE_PS8622
>         ---help---
>           Parade eDP-LVDS bridge chip driver.
>
> +config DRM_PARADE_PS8640
> +       tristate "Parade PS8640 MIPI DSI to eDP Converter"
> +       depends on OF && I2C
> +       select DRM_KMS_HELPER

I think this needs:

select DRM_MIPI_DSI

Otherwise:
drivers/gpu/drm/bridge/parade-ps8640.c:400: undefined reference to
`of_find_mipi_dsi_host_by_node'
drivers/gpu/drm/bridge/parade-ps8640.c:411: undefined reference to
`mipi_dsi_attach'

> +       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 f13c33d..fbe38dc 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.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..0230ab5
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,1084 @@
> +/*
> + * 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/delay.h>
> +#include <linux/err.h>
> +#include <linux/firmware.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <asm/unaligned.h>
> +#include <drm/drm_panel.h>
> +
> +#include <drmP.h>
> +#include <drm_atomic_helper.h>
> +#include <drm_crtc_helper.h>
> +#include <drm_crtc.h>
> +#include <drm_mipi_dsi.h>
> +
> +#define PAGE2_SPI_CFG3         0x82
> +#define I2C_TO_SPI_RESET       0x20
> +#define PAGE2_ROMADD_BYTE1     0x8e
> +#define PAGE2_ROMADD_BYTE2     0x8f
> +#define PAGE2_SWSPI_WDATA      0x90
> +#define PAGE2_SWSPI_RDATA      0x91
> +#define PAGE2_SWSPI_LEN                0x92
> +#define PAGE2_SWSPI_CTL                0x93
> +#define TRIGGER_NO_READBACK    0x05
> +#define TRIGGER_READBACK       0x01
> +#define PAGE2_SPI_STATUS       0x9e
> +#define PAGE2_GPIO_L           0xa6
> +#define PAGE2_GPIO_H           0xa7
> +#define PS_GPIO9               BIT(1)
> +#define PAGE2_IROM_CTRL                0xb0
> +#define IROM_ENABLE            0xc0
> +#define IROM_DISABLE           0x80
> +#define PAGE2_SW_REST          0xbc
> +#define PAGE2_ENCTLSPI_WR      0xda
> +#define PAGE2_I2C_BYPASS       0xea
> +#define I2C_BYPASS_EN          0xd0
> +
> +#define PAGE3_SET_ADD          0xfe
> +#define PAGE3_SET_VAL          0xff
> +#define VDO_CTL_ADD            0x13
> +#define VDO_DIS                        0x18
> +#define VDO_EN                 0x1c
> +
> +#define PAGE4_REV_L            0xf0
> +#define PAGE4_REV_H            0xf1
> +#define PAGE4_CHIP_L           0xf2
> +#define PAGE4_CHIP_H           0xf3
> +
> +/* Firmware */
> +#define SPI_MAX_RETRY_CNT      8
> +#define PS_FW_NAME             "ps864x_fw.bin"
> +
> +#define FW_CHIP_ID_OFFSET      0
> +#define FW_VERSION_OFFSET      2
> +
> +#define bridge_to_ps8640(e)    container_of(e, struct ps8640, bridge)
> +#define connector_to_ps8640(e) container_of(e, struct ps8640, connector)
> +
> +struct ps8640_info {
> +       u8 family_id;
> +       u8 variant_id;
> +       u16 version;
> +};
> +
> +struct ps8640 {
> +       struct drm_connector connector;
> +       struct drm_bridge bridge;
> +       struct mipi_dsi_device *dsi;
> +       struct i2c_client *page[8];
> +       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;
> +       bool enabled;
> +
> +       /* firmware file name */
> +       bool in_fw_update;
> +       char *fw_file;
> +       struct ps8640_info info;
> +};
> +
> +static const u8 enc_ctrl_code[6] = {0xaa, 0x55, 0x50, 0x41, 0x52, 0x44};
> +
> +static int ps8640_regr(struct i2c_client *client, u8 reg, u8 *data,
> +                      u16 data_len)

IMHO, ps8640_read() and ps8640_write() are clearer than regr and regw.

> +{
> +       int ret;
> +       struct i2c_msg msgs[] = {
> +               {
> +                .addr = client->addr,
> +                .flags = 0,
> +                .len = 1,
> +                .buf = &reg,
> +                },
> +               {
> +                .addr = client->addr,
> +                .flags = I2C_M_RD,
> +                .len = data_len,
> +                .buf = data,
> +                }
> +       };
> +
> +       ret = i2c_transfer(client->adapter, msgs, 2);
> +
> +       if (ret == 2)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_regw_bytes(struct i2c_client *client, u8 *data,
> +                            u16 data_len)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = data_len;
> +       msg.buf = data;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_regw_byte(struct i2c_client *client, u8 reg,  u8 data)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +       u8 buf[] = {reg, data};
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = sizeof(buf);
> +       msg.buf = buf;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[5];
> +       u8 fw_ver[2];
> +
> +       ps8640_regr(client, 0x4, fw_ver, 2);
> +       ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
> +
> +       DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
> +}
> +
> +static int ps8640_bridge_enable(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[3];
> +       int ret;
> +       u8 vdo_ctrl_buf[3] = {PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN};
> +
> +       ret = ps8640_regw_bytes(client, vdo_ctrl_buf, 3);
> +       return ret;

nit:  Just:

   return ps8640_regw_bytes(client, vdo_ctrl_buf, 3);

> +}
> +
> +static void ps8640_pre_enable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       struct i2c_client *client = ps_bridge->page[2];
> +       int err, retry_cnt = 0;
> +       u8 set_vdo_done;
> +
> +       if (ps_bridge->in_fw_update)
> +               return;
> +
> +       if (ps_bridge->enabled)
> +               return;
> +
> +       err = drm_panel_prepare(ps_bridge->panel);
> +       if (err < 0) {
> +               DRM_ERROR("failed to prepare panel: %d\n", err);
> +               return;
> +       }
> +
> +       gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> +
> +       err = regulator_enable(ps_bridge->pwr_1v2_supply);
> +       if (err < 0) {
> +               DRM_ERROR("failed to enable vdd12-supply: %d\n", err);
> +               goto err_panel_unprepare;
> +       }
> +
> +       err = regulator_enable(ps_bridge->pwr_3v3_supply);
> +       if (err < 0) {
> +               DRM_ERROR("failed to enable vdd33-supply: %d\n", err);
> +               goto err_regulator_1v2_disable;
> +       }
> +
> +       usleep_range(500, 700);
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> +
> +       /*
> +        * Wait for the ps8640 embed mcu ready
> +        * First wait 200ms and then check the mcu ready flag every 20ms
> +        */
> +       msleep(200);
> +       do {
> +               err = ps8640_regr(client, PAGE2_GPIO_H, &set_vdo_done, 1);
> +               if (err < 0) {
> +                       DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
> +                       goto err_regulator_1v2_disable;
> +               }
> +               msleep(20);
> +       } while ((retry_cnt++ < 10) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> +
> +       if (ps_bridge->info.version == 0)
> +               ps8640_get_mcu_fw_version(ps_bridge);
> +       /* Switch access edp panel's edid through i2c */
> +       ps8640_regw_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
> +       ps_bridge->enabled = true;
> +
> +       return;
> +
> +err_regulator_1v2_disable:
> +       regulator_disable(ps_bridge->pwr_1v2_supply);
> +err_panel_unprepare:
> +       drm_panel_unprepare(ps_bridge->panel);
> +}
> +
> +static void ps8640_enable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       err = ps8640_bridge_enable(ps_bridge);
> +       if (err)
> +               DRM_ERROR("failed to enable unmutevideo: %d\n", err);
> +
> +       err = drm_panel_enable(ps_bridge->panel);
> +       if (err < 0)
> +               DRM_ERROR("failed to enable panel: %d\n", err);
> +}
> +
> +static void ps8640_disable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       err = drm_panel_disable(ps_bridge->panel);
> +       if (err < 0)
> +               DRM_ERROR("failed to disable panel: %d\n", err);

Should there be a ps8640_bridge_disable() here, to undo ps8640_bridge_enable()?

> +}
> +
> +static void ps8640_post_disable(struct drm_bridge *bridge)
> +{
> +       struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> +       int err;
> +
> +       if (ps_bridge->in_fw_update)
> +               return;
> +
> +       if (!ps_bridge->enabled)
> +               return;
> +
> +       ps_bridge->enabled = false;
> +
> +       gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> +       gpiod_set_value(ps_bridge->gpio_slp_n, 0);
> +       regulator_disable(ps_bridge->pwr_3v3_supply);
> +       regulator_disable(ps_bridge->pwr_1v2_supply);
> +
> +       err = drm_panel_unprepare(ps_bridge->panel);
> +       if (err)
> +               DRM_ERROR("failed to unprepare panel: %d\n", err);
> +}
> +
> +static int ps8640_get_modes(struct drm_connector *connector)
> +{
> +       struct ps8640 *ps_bridge = connector_to_ps8640(connector);
> +       bool power_off;
> +       int num_modes = 0;
> +
> +       power_off = !ps_bridge->enabled;
> +       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +       num_modes = drm_panel_get_modes(ps_bridge->panel);
> +
> +       if (power_off)
> +               ps8640_post_disable(&ps_bridge->bridge);
> +
> +       return num_modes;
> +}
> +
> +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);
> +       struct device *dev = &ps_bridge->page[0]->dev;
> +       struct device_node *np = dev->of_node;
> +       struct device_node *port, *in_ep;
> +       struct device_node *dsi_node = NULL;
> +       struct mipi_dsi_host *host = ps_bridge->dsi->host;
> +       int ret;
> +
> +       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: %d\n", ret);
> +               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);
> +
> +       /* port at 0 is ps8640 dsi input port */
> +       port = of_graph_get_port_by_id(np, 0);
> +       if (port) {
> +               in_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               if (in_ep) {
> +                       dsi_node = of_graph_get_remote_port_parent(in_ep);
> +                       of_node_put(in_ep);
> +               }
> +       }
> +       if (dsi_node) {
> +               host = of_find_mipi_dsi_host_by_node(dsi_node);
> +               of_node_put(dsi_node);
> +               if (!host)
> +                       return -ENODEV;
> +       }
> +
> +       ps_bridge->dsi->host = host;
> +       ps_bridge->dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
> +                                    MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
> +       ps_bridge->dsi->format = MIPI_DSI_FMT_RGB888;
> +       ps_bridge->dsi->lanes = 4;
> +       ret = mipi_dsi_attach(ps_bridge->dsi);
> +       if (ret) {
> +               drm_panel_detach(ps_bridge->panel);
> +               return ret;
> +       }
> +
> +       return ret;
> +}
> +
> +static const struct drm_bridge_funcs ps8640_bridge_funcs = {
> +       .attach = ps8640_bridge_attach,
> +       .disable = ps8640_disable,
> +       .post_disable = ps8640_post_disable,
> +       .pre_enable = ps8640_pre_enable,
> +       .enable = ps8640_enable,
> +};
> +
> +static ssize_t ps8640_fw_file_show(struct device *dev,
> +                                  struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +
> +       return scnprintf(buf, PAGE_SIZE, "%s\n", ps_bridge->fw_file);
> +}
> +
> +static int ps8640_update_file_name(struct device *dev, char **file_name,
> +                                  const char *buf, size_t count)

Just remove this function now since fw_file is always just PS_FW_NAME.

> +{
> +       char *new_file_name;
> +
> +       /* Simple sanity check */
> +       if (count > 64) {
> +               dev_warn(dev, "File name too long\n");
> +               return -EINVAL;
> +       }
> +
> +       new_file_name = devm_kmalloc(dev, count + 1, GFP_KERNEL);
> +       if (!new_file_name)
> +               return -ENOMEM;
> +
> +       memcpy(new_file_name, buf, count + 1);
> +
> +       /* Echo into the sysfs entry may append newline at the end of buf */
> +       if (new_file_name[count - 1] == '\n')
> +               count--;
> +
> +       new_file_name[count] = '\0';
> +
> +       if (*file_name)
> +               devm_kfree(dev, *file_name);
> +
> +       *file_name = new_file_name;
> +
> +       return 0;
> +}
> +
> +/* Firmware Version is returned as Major.Minor.Build */
> +static ssize_t ps8640_fw_version_show(struct device *dev,
> +                                     struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +       struct ps8640_info *info = &ps_bridge->info;
> +
> +       return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
> +                        info->version & 0xff);

Just remove this sysfs entry since fw_file is always just PS_FW_NAME.

> +}
> +
> +/* Hardware Version is returned as FamilyID.VariantID */
> +static ssize_t ps8640_hw_version_show(struct device *dev,
> +                                     struct device_attribute *attr, char *buf)
> +{
> +       struct ps8640 *ps_bridge = dev_get_drvdata(dev);
> +       struct ps8640_info *info = &ps_bridge->info;
> +
> +       return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
> +                        info->variant_id);
> +}
> +
> +static int ps8640_spi_send_cmd(struct ps8640 *ps_bridge, u8 *cmd, u8 cmd_len)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 i;
> +       int ret;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto err;
> +
> +       /* write command in write port */
> +       for (i = 0; i < cmd_len; i++) {
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
> +               if (ret)
> +                       goto err;
> +       }
> +       /* command length */
> +       ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, cmd_len - 1);
> +       if (ret)
> +               goto err;
> +       /* trigger read */
> +       ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL, TRIGGER_NO_READBACK);
> +       if (ret)
> +               goto err;

nit: you can probably combine the write of PAGE2_SWSPI_LEN &
PAGE2_SWSPI_CTL into a single i2c transaction, here and in
ps8640_wait_spi_nobusy().

> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto err;
> +
> +       return 0;
> +
> +err:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_wait_spi_ready(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_rdy_st, retry_cnt = 0;
> +
> +       do {
> +               ps8640_regr(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
> +               msleep(20);
> +               if ((retry_cnt == SPI_MAX_RETRY_CNT) &&
> +                   ((spi_rdy_st & 0x0c) != 0x0c)) {
> +                       dev_err(&client->dev, "wait spi ready timeout\n");
> +                       return -EBUSY;
> +               }
> +       } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
> +                (spi_rdy_st & 0x0c) == 0x0c);
> +
> +       return 0;
> +}
> +
> +static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_status, retry_cnt = 0;
> +       int ret;
> +
> +       do {
> +               /* 0x05 RDSR; Read-Status-Register */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_WDATA, 0x05);

Please #define this constant 0x05.


> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* command length */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_LEN, 0x00);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* trigger read */
> +               ret = ps8640_regw_byte(client, PAGE2_SWSPI_CTL,
> +                                      TRIGGER_READBACK);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* delay for cmd send */
> +               usleep_range(100, 300);
> +               /* wait for SPI ROM until not busy */
> +               ret = ps8640_regr(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +       } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
> +                (spi_status & 0x0c) == 0x0c);
> +
> +       if ((retry_cnt > SPI_MAX_RETRY_CNT) && (spi_status & 0x0c) != 0x0c) {

Please #define this constant 0x0c.


> +               ret = -EBUSY;
> +               dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
> +               goto err_timeout;
> +       }
> +
> +       return 0;
> +
> +err_send_cmd_exit:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +
> +err_timeout:
> +       return ret;
> +}
> +
> +static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       int ret;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_ready(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_nobusy(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto exit;
> +
> +exit:
> +       if (ret)
> +               dev_err(&client->dev, "wait ps8640 rom idle fail: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ps8640_spi_dl_mode(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       int ret;
> +
> +       /* switch ps8640 mode to spi dl mode */
> +       gpiod_set_value(ps_bridge->gpio_mode_sel_n, 0);
> +
> +       /* reset spi interface */
> +       ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0xc0);

Please #define these constants, 0xc0 & 0x40.  Is this a bit field?

> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_regw_byte(client, PAGE2_SW_REST, 0x40);
> +       if (ret)
> +               goto exit;
> +
> +exit:
> +       if (ret)
> +               dev_err(&client->dev, "fail reset spi interface: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ps8640_rom_prepare(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       struct device *dev = &client->dev;
> +       u8 i, cmd[2];
> +       int ret;
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;

Please #define magic numbers / constants in this function.


> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "failed enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* disable all protection */
> +       cmd[0] = 0x01;
> +       cmd[1] = 0x00;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +       if (ret) {
> +               dev_err(dev, "fail disable all protection: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* wait for SPI module ready */
> +       ret = ps8640_wait_rom_idle(ps_bridge);
> +       if (ret) {
> +               dev_err(dev, "fail wait rom idle: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       for (i = 0; i < 6; i++)
> +               ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
> +       ps8640_regw_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "fail enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* chip erase command */
> +       cmd[0] = 0xc7;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "fail disable all protection: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ret = ps8640_wait_rom_idle(ps_bridge);
> +       if (ret) {
> +               dev_err(dev, "fail wait rom idle: %d\n", ret);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
> +                                   const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct ps8640_info *info = &ps_bridge->info;
> +       u16 fw_chip_id, fw_version_id;
> +
> +       /*
> +        * Get the chip_id from the firmware. Make sure that it is the
> +        * right controller to do the firmware and config update.
> +        */
> +       fw_chip_id = get_unaligned_le16(fw->data + FW_CHIP_ID_OFFSET);
> +
> +       if (fw_chip_id != 0x8640) {
> +               dev_err(&client->dev,
> +                       "chip id mismatch: fw 0x%x vs. chip 0x8640\n",
> +                       fw_chip_id);
> +               return -ENODEV;
> +       }
> +
> +       fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
> +
> +       if (fw_chip_id != info->version) {
> +               dev_err(&client->dev,
> +                       "fw version mismatch: fw %d.%d vs. chip %d.%d\n",
> +                       fw_version_id >> 8, fw_version_id & 0xff,
> +                       info->version >> 8, info->version & 0xff);
> +               return -ENODEV;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_write_rom(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct device *dev = &client->dev;
> +       struct i2c_client *client2 = ps_bridge->page[2];
> +       struct i2c_client *client7 = ps_bridge->page[7];
> +       unsigned int pos = 0;
> +       u8 buf[257], rom_page_id_buf[3];
> +       int ret;
> +       u16 cpy_len;
> +
> +       ps8640_regw_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
> +       msleep(100);
> +       ps8640_regw_byte(client2, PAGE2_SPI_CFG3, 0x00);
> +
> +       while (pos < fw->size) {
> +               rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
> +               rom_page_id_buf[1] = (pos >> 8) & 0xff;
> +               rom_page_id_buf[2] = (pos >> 16) & 0xff;
> +               ret = ps8640_regw_bytes(client2, rom_page_id_buf, 3);
> +               if (ret)
> +                       goto error;
> +               cpy_len = fw->size >= 256 + pos ? 256 : fw->size - pos;
> +               buf[0] = 0;
> +               memcpy(buf + 1, fw->data + pos, cpy_len);
> +               ret = ps8640_regw_bytes(client7, buf, cpy_len + 1);
> +               if (ret)
> +                       goto error;
> +
> +               pos += cpy_len;
> +
> +               dev_dbg(dev, "fw update completed %u / %zu bytes\n", pos,
> +                       fw->size);
> +       }
> +       return 0;
> +
> +error:
> +       dev_err(dev, "failed write extenal flash, %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_spi_normal_mode(struct ps8640 *ps_bridge)
> +{
> +       u8 cmd[2];
> +       struct i2c_client *client = ps_bridge->page[2];

Please #define magic numbers / constants in this function.

> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = 0x06;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +
> +       /* protect BPL/BP0/BP1 */
> +       cmd[0] = 0x01;
> +       cmd[1] = 0x8c;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +
> +       /* wait for SPI rom ready */
> +       ps8640_wait_rom_idle(ps_bridge);
> +
> +       /* disable PS8640 mapping function */
> +       ps8640_regw_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
> +
> +       gpiod_set_value(ps_bridge->gpio_mode_sel_n, 1);
> +       return 0;
> +}
> +
> +static int ps8640_enter_bl(struct ps8640 *ps_bridge)
> +{
> +       int ret;
> +
> +       ret = ps8640_spi_dl_mode(ps_bridge);
> +       if (ret)
> +               return ret;
> +
> +       ps_bridge->in_fw_update = true;

Set in_fw_update before ps8640_spi_dl_mode() to avoid a race between
between ps8640_spi_dl_mode() and ps8640_pre_enable / post_disable().

> +       return 0;
> +}
> +
> +static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       ps_bridge->in_fw_update = false;
> +       ps8640_spi_normal_mode(ps_bridge);

Set in_fw_update after ps8640_spi_normal_mode() to avoid a race
between between ps8640_spi_normal_mode() and ps8640_pre_enable /
post_disable().

> +}
> +
> +static int ps8640_load_fw(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       struct device *dev = &client->dev;
> +       int ret;
> +       bool ps8640_status_backup = ps_bridge->enabled;
> +
> +       if (!ps_bridge->in_fw_update) {
> +               if (!ps8640_status_backup)
> +                       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +               ret = ps8640_enter_bl(ps_bridge);
> +               if (ret)
> +                       goto exit;
> +       }
> +
> +       ret = ps8640_validate_firmware(ps_bridge, fw);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_rom_prepare(ps_bridge);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_write_rom(ps_bridge, fw);
> +
> +exit:
> +       if (ret)
> +               dev_err(dev, "Failed to load firmware, %d\n", ret);
> +
> +       ps8640_exit_bl(ps_bridge, fw);
> +       if (!ps8640_status_backup)
> +               ps8640_post_disable(&ps_bridge->bridge);
> +       return ret;
> +}
> +
> +static ssize_t ps8640_update_fw_store(struct device *dev,
> +                                     struct device_attribute *attr,
> +                                     const char *buf, size_t count)
> +{
> +       struct i2c_client *client = to_i2c_client(dev);
> +       struct ps8640 *ps_bridge = i2c_get_clientdata(client);
> +       const struct firmware *fw;
> +       int error;
> +
> +       error = request_firmware(&fw, ps_bridge->fw_file, dev);
> +       if (error) {
> +               dev_err(dev, "Unable to open firmware %s: %d\n",
> +                       ps_bridge->fw_file, error);
> +               return error;
> +       }
> +
> +       error = ps8640_load_fw(ps_bridge, fw);
> +       if (error)
> +               dev_err(dev, "The firmware update failed(%d)\n", error);
> +       else
> +               dev_info(dev, "The firmware update succeeded\n");
> +
> +       release_firmware(fw);
> +       return error ? error : count;
> +}
> +
> +static DEVICE_ATTR(fw_file, S_IRUGO, ps8640_fw_file_show, NULL);
> +static DEVICE_ATTR(fw_version, S_IRUGO, ps8640_fw_version_show, NULL);
> +static DEVICE_ATTR(hw_version, S_IRUGO, ps8640_hw_version_show, NULL);
> +static DEVICE_ATTR(update_fw, S_IWUSR, NULL, ps8640_update_fw_store);
> +
> +static struct attribute *ps8640_attrs[] = {
> +       &dev_attr_fw_file.attr,
> +       &dev_attr_fw_version.attr,
> +       &dev_attr_hw_version.attr,
> +       &dev_attr_update_fw.attr,
> +       NULL
> +};
> +
> +static const struct attribute_group ps8640_attr_group = {
> +       .attrs = ps8640_attrs,
> +};
> +
> +static void ps8640_remove_sysfs_group(void *data)
> +{
> +       struct ps8640 *ps_bridge = data;
> +
> +       sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
> +}
> +
> +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 *port, *out_ep;
> +       struct device_node *panel_node = NULL;
> +       int i, ret;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
> +                                     GFP_KERNEL);
> +       if (!ps_bridge) {
> +               ret = -ENOMEM;
> +               goto exit;

nit: instead of "goto exit", you can just:

  return -ENOMEM; (for all of these "goto exit")

> +       }
> +       /* port at 1 is ps8640 output port */
> +       port = of_graph_get_port_by_id(np, 1);
> +       if (port) {
> +               out_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               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) {
> +                       ret = -EPROBE_DEFER;
> +                       goto exit;
> +               }
> +       }
> +
> +       ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
> +       if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
> +               dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");
> +       if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_1v2_supply);
> +               dev_err(dev, "cannot get vdd12 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       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);
> +               dev_err(dev, "cannot get gpio_mode_sel_n %d\n", ret);

nit: I'd use the gpio's device tree name in the error message here, so
"mode-sel".
Same for the others, below.

  dev_err(dev, "cannot get gpio 'mode-sel' %d\n", ret);

Thanks,
-Dan

Re: [PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Daniel Kurtz]

Hi Jitao,

One more comment, inline...

On Mon, Feb 1, 2016 at 12:13 PM, Jitao Shi <jitao.shi@mediatek.com> wrote:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>

[snip]

> +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 *port, *out_ep;
> +       struct device_node *panel_node = NULL;
> +       int i, ret;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
> +                                     GFP_KERNEL);
> +       if (!ps_bridge) {
> +               ret = -ENOMEM;
> +               goto exit;
> +       }
> +       /* port@1 is ps8640 output port */
> +       port = of_graph_get_port_by_id(np, 1);
> +       if (port) {
> +               out_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               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) {
> +                       ret = -EPROBE_DEFER;
> +                       goto exit;
> +               }
> +       }
> +
> +       ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
> +       if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
> +               dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");

Since we have two regulators, and they must always be enabled &
disabled together, we can just use the 'bulk regulator' APIs:

  devm_regulator_bulk_get()
  regulator_bulk_enable()
  regulator_bulk_disable()

Re: [PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Daniel Kurtz]

Hi Jitao,

One more comment, inline...

On Mon, Feb 1, 2016 at 12:13 PM, Jitao Shi <jitao.shi@mediatek.com> wrote:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>

[snip]

> +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 *port, *out_ep;
> +       struct device_node *panel_node = NULL;
> +       int i, ret;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
> +                                     GFP_KERNEL);
> +       if (!ps_bridge) {
> +               ret = -ENOMEM;
> +               goto exit;
> +       }
> +       /* port@1 is ps8640 output port */
> +       port = of_graph_get_port_by_id(np, 1);
> +       if (port) {
> +               out_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               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) {
> +                       ret = -EPROBE_DEFER;
> +                       goto exit;
> +               }
> +       }
> +
> +       ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
> +       if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
> +               dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");

Since we have two regulators, and they must always be enabled &
disabled together, we can just use the 'bulk regulator' APIs:

  devm_regulator_bulk_get()
  regulator_bulk_enable()
  regulator_bulk_disable()
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[PATCH v8 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Daniel Kurtz]

Hi Jitao,

One more comment, inline...

On Mon, Feb 1, 2016 at 12:13 PM, Jitao Shi <jitao.shi@mediatek.com> wrote:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>

[snip]

> +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 *port, *out_ep;
> +       struct device_node *panel_node = NULL;
> +       int i, ret;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       ps_bridge->dsi = devm_kzalloc(dev, sizeof(struct mipi_dsi_device),
> +                                     GFP_KERNEL);
> +       if (!ps_bridge) {
> +               ret = -ENOMEM;
> +               goto exit;
> +       }
> +       /* port at 1 is ps8640 output port */
> +       port = of_graph_get_port_by_id(np, 1);
> +       if (port) {
> +               out_ep = of_get_child_by_name(port, "endpoint");
> +               of_node_put(port);
> +               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) {
> +                       ret = -EPROBE_DEFER;
> +                       goto exit;
> +               }
> +       }
> +
> +       ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33");
> +       if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> +               ret = PTR_ERR(ps_bridge->pwr_3v3_supply);
> +               dev_err(dev, "cannot get vdd33 supply: %d\n", ret);
> +               goto exit;
> +       }
> +
> +       ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12");

Since we have two regulators, and they must always be enabled &
disabled together, we can just use the 'bulk regulator' APIs:

  devm_regulator_bulk_get()
  regulator_bulk_enable()
  regulator_bulk_disable()