Re: [v17 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Enric Balletbo Serra]

Hi Jitao,

2016-08-27 8:44 GMT+02:00 Jitao Shi <jitao.shi@xxxxxxxxxxxx>:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
>
> Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
> Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> ---
> Changes since v16:
>  - Disable ps8640 DSI MCS Function.
>  - Rename gpios name more clearly.
>  - Tune the ps8640 power on sequence.
>
> Changes since v15:
>  - Drop drm_connector_(un)register calls from parade ps8640.
>    The main DRM driver mtk_drm_drv now calls
>    drm_connector_register_all() after drm_dev_register() in the
>    mtk_drm_bind() function. That function should iterate over all
>    connectors and call drm_connector_register() for each of them.
>    So, remove drm_connector_(un)register calls from parade ps8640.
>
> Changes since v14:
>  - update copyright info.
>  - change bridge_to_ps8640 and connector_to_ps8640 to inline function.
>  - fix some coding style.
>  - use sizeof as array counter.
>  - use drm_get_edid when read edid.
>  - add mutex when firmware updating.
>
> Changes since v13:
>  - add const on data, ps8640_write_bytes(struct i2c_client *client, const u8 *data, u16 data_len)
>  - fix PAGE2_SW_REST tyro.
>  - move the buf[3] init to entrance of the function.
>
> Changes since v12:
>  - fix hw_chip_id build warning
>
> Changes since v11:
>  - Remove depends on I2C, add DRM depends
>  - Reuse ps8640_write_bytes() in ps8640_write_byte()
>  - Use timer check for polling like the routines in <linux/iopoll.h>
>  - Fix no drm_connector_unregister/drm_connector_cleanup when ps8640_bridge_attach fail
>  - Check the ps8640 hardware id in ps8640_validate_firmware
>  - Remove fw_version check
>  - Move ps8640_validate_firmware before ps8640_enter_bl
>  - Add ddc_i2c unregister when probe fail and ps8640_remove
> ---
>  drivers/gpu/drm/bridge/Kconfig         |   12 +
>  drivers/gpu/drm/bridge/Makefile        |    1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c | 1077 ++++++++++++++++++++++++++++++++
>  3 files changed, 1090 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 b590e67..c59d043 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -50,6 +50,18 @@ 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 DRM
> +       depends on OF
> +       select DRM_KMS_HELPER
> +       select DRM_MIPI_DSI
> +       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
> +
>  config DRM_SII902X
>         tristate "Silicon Image sii902x RGB/HDMI bridge"
>         depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index efdb07e..3360537 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -5,6 +5,7 @@ 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-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
>  obj-$(CONFIG_DRM_SII902X) += sii902x.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>  obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix/
> diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
> new file mode 100644
> index 0000000..7d67431
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,1077 @@
> +/*
> + * Copyright (c) 2016 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_edid.h>
> +#include <drm_mipi_dsi.h>
> +
> +#define PAGE1_VSTART           0x6b
> +#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 SPI_READY              0x0c
> +#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_RESET         0xbc
> +#define SPI_SW_RESET           BIT(7)
> +#define MPU_SW_RESET           BIT(6)
> +#define PAGE2_ENCTLSPI_WR      0xda
> +#define PAGE2_I2C_BYPASS       0xea
> +#define I2C_BYPASS_EN          0xd0
> +#define PAGE2_MCS_EN           0xf3
> +#define MCS_EN                 BIT(0)
> +#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 PS_FW_NAME             "ps864x_fw.bin"
> +

About the firmware discussion I think that if you want to maintain the
upgrade firmware thing you should also include this patch in the
series.

 https://chromium-review.googlesource.com/#/c/317221/

Otherwise, if this is not really needed I think that remove this from
the driver is the best. Just an opinion, this is something the
maintainer should decide.

> +#define FW_CHIP_ID_OFFSET      0
> +#define FW_VERSION_OFFSET      2
> +#define EDID_I2C_ADDR          0x50
> +
> +#define WRITE_STATUS_REG_CMD   0x01
> +#define READ_STATUS_REG_CMD    0x05
> +#define BUSY                   BIT(0)
> +#define CLEAR_ALL_PROTECT      0x00
> +#define BLK_PROTECT_BITS       0x0c
> +#define STATUS_REG_PROTECT     BIT(7)
> +#define WRITE_ENABLE_CMD       0x06
> +#define CHIP_ERASE_CMD         0xc7
> +#define MAX_DEVS               0x8
> +
> +struct ps8640_info {
> +       u8 family_id;
> +       u8 variant_id;
> +       u16 version;
> +};
> +
> +struct ps8640 {
> +       struct drm_connector connector;
> +       struct drm_bridge bridge;
> +       struct edid *edid;
> +       struct mipi_dsi_device dsi;
> +       struct i2c_client *page[MAX_DEVS];
> +       struct i2c_client *ddc_i2c;
> +       struct regulator_bulk_data supplies[2];
> +       struct drm_panel *panel;
> +       struct gpio_desc *gpio_reset;
> +       struct gpio_desc *gpio_power_down;
> +       struct gpio_desc *gpio_mode_sel;
> +       bool enabled;
> +
> +       /* firmware file info */
> +       struct ps8640_info info;
> +       bool in_fw_update;
> +       /* for firmware update protect */
> +       struct mutex fw_mutex;
> +};
> +
> +static const u8 enc_ctrl_code[6] = { 0xaa, 0x55, 0x50, 0x41, 0x52, 0x44 };
> +static const u8 hw_chip_id[4] = { 0x00, 0x0a, 0x00, 0x30 };
> +
> +static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
> +{
> +       return container_of(e, struct ps8640, bridge);
> +}
> +
> +static inline struct ps8640 *connector_to_ps8640(struct drm_connector *e)
> +{
> +       return container_of(e, struct ps8640, connector);
> +}
> +
> +static int ps8640_read(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_write_bytes(struct i2c_client *client, const u8 *data,
> +                             u16 data_len)
> +{
> +       int ret;
> +       struct i2c_msg msg;
> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = data_len;
> +       msg.buf = (u8 *)data;
> +
> +       ret = i2c_transfer(client->adapter, &msg, 1);
> +       if (ret == 1)
> +               return 0;
> +       if (ret < 0)
> +               return ret;
> +       else
> +               return -EIO;
> +}
> +
> +static int ps8640_write_byte(struct i2c_client *client, u8 reg,  u8 data)
> +{
> +       u8 buf[] = { reg, data };
> +
> +       return ps8640_write_bytes(client, buf, sizeof(buf));
> +}
> +
> +static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[5];
> +       u8 fw_ver[2];
> +
> +       ps8640_read(client, 0x4, fw_ver, sizeof(fw_ver));
> +       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_unmute(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[3];
> +       u8 vdo_ctrl_buf[3] = { PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN };
> +
> +       return ps8640_write_bytes(client, vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
> +}
> +
> +static int ps8640_bridge_mute(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[3];
> +       u8 vdo_ctrl_buf[3] = { PAGE3_SET_ADD, VDO_CTL_ADD, VDO_DIS };
> +
> +       return ps8640_write_bytes(client, vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
> +}
> +
> +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];
> +       struct i2c_client *page1 = ps_bridge->page[1];
> +       int err;
> +       u8 set_vdo_done, mcs_en, vstart;
> +       ktime_t timeout;
> +
> +       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;
> +       }
> +
> +       err = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
> +                                   ps_bridge->supplies);
> +       if (err < 0) {
> +               DRM_ERROR("cannot enable regulators %d\n", err);
> +               goto err_panel_unprepare;
> +       }
> +
> +       gpiod_set_value(ps_bridge->gpio_power_down, 1);
> +       gpiod_set_value(ps_bridge->gpio_reset, 0);
> +       usleep_range(2000, 2500);
> +       gpiod_set_value(ps_bridge->gpio_reset, 1);
> +
> +       /*
> +        * Wait for the ps8640 embed mcu ready
> +        * First wait 200ms and then check the mcu ready flag every 20ms
> +        */
> +       msleep(200);
> +
> +       timeout = ktime_add_ms(ktime_get(), 200);
> +       for (;;) {
> +               err = ps8640_read(client, PAGE2_GPIO_H, &set_vdo_done, 1);
> +               if (err < 0) {
> +                       DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
> +                       goto err_regulators_disable;
> +               }
> +               if ((set_vdo_done & PS_GPIO9) == PS_GPIO9)
> +                       break;
> +               if (ktime_compare(ktime_get(), timeout) > 0)
> +                       break;
> +               msleep(20);
> +       }
> +
> +       msleep(50);
> +
> +       ps8640_read(page1, PAGE1_VSTART, &vstart, 1);
> +       DRM_INFO("PS8640 PAGE1.0x6B = 0x%x\n", vstart);
> +
> +       /**
> +        * The Manufacturer Command Set (MCS) is a device dependent interface
> +        * intended for factory programming of the display module default
> +        * parameters. Once the display module is configured, the MCS shall be
> +        * disabled by the manufacturer. Once disabled, all MCS commands are
> +        * ignored by the display interface.
> +        */
> +       ps8640_read(client, PAGE2_MCS_EN, &mcs_en, 1);
> +       ps8640_write_byte(client, PAGE2_MCS_EN, mcs_en & ~MCS_EN);
> +
> +       if (ps_bridge->info.version == 0)
> +               ps8640_get_mcu_fw_version(ps_bridge);
> +
> +       err = ps8640_bridge_unmute(ps_bridge);
> +       if (err)
> +               DRM_ERROR("failed to enable unmutevideo: %d\n", err);
> +       /* Switch access edp panel's edid through i2c */
> +       ps8640_write_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
> +       ps_bridge->enabled = true;
> +
> +       return;
> +
> +err_regulators_disable:
> +       regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
> +                              ps_bridge->supplies);
> +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 = 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;
> +
> +       err = ps8640_bridge_mute(ps_bridge);
> +       if (err < 0)
> +               DRM_ERROR("failed to unmutevideo: %d\n", err);
> +
> +       gpiod_set_value(ps_bridge->gpio_reset, 0);
> +       gpiod_set_value(ps_bridge->gpio_power_down, 0);
> +       err = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
> +                                    ps_bridge->supplies);
> +       if (err < 0)
> +               DRM_ERROR("cannot disable regulators %d\n", err);
> +
> +       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);
> +       struct edid *edid;
> +       int num_modes = 0;
> +       bool power_off;
> +
> +       if (ps_bridge->edid)
> +               return drm_add_edid_modes(connector, ps_bridge->edid);
> +
> +       power_off = !ps_bridge->enabled;
> +       ps8640_pre_enable(&ps_bridge->bridge);
> +
> +       edid = drm_get_edid(connector, ps_bridge->ddc_i2c->adapter);
> +       if (!edid)
> +               goto out;
> +
> +       ps_bridge->edid = edid;
> +       drm_mode_connector_update_edid_property(connector, ps_bridge->edid);
> +       num_modes = drm_add_edid_modes(connector, ps_bridge->edid);
> +
> +out:
> +       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 = 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 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,
> +       .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 *port, *in_ep;
> +       struct device_node *dsi_node = NULL;
> +       struct mipi_dsi_host *host = NULL;
> +       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);
> +
> +       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(dev->of_node, 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) {
> +                       ret = -ENODEV;
> +                       goto err;
> +               }
> +       }
> +
> +       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)
> +               goto err;
> +
> +       return 0;
> +err:
> +       if (ps_bridge->panel)
> +               drm_panel_detach(ps_bridge->panel);
> +       drm_connector_cleanup(&ps_bridge->connector);
> +       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,
> +};
> +
> +/* Firmware Version is returned as Major.Minor */
> +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, buf[3] = { PAGE2_SWSPI_LEN, cmd_len - 1, TRIGGER_NO_READBACK };
> +       int ret;
> +
> +       ret = ps8640_write_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_write_byte(client, PAGE2_SWSPI_WDATA, cmd[i]);
> +               if (ret)
> +                       goto err_irom_disable;
> +       }
> +
> +       ret = ps8640_write_bytes(client, buf, sizeof(buf));
> +       if (ret)
> +               goto err_irom_disable;
> +
> +       ret = ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto err;
> +
> +       return 0;
> +err_irom_disable:
> +       ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +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;
> +       ktime_t timeout;
> +
> +       timeout = ktime_add_ms(ktime_get(), 200);
> +       for (;;) {
> +               ps8640_read(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
> +               if ((spi_rdy_st & SPI_READY) != SPI_READY)
> +                       break;
> +
> +               if (ktime_compare(ktime_get(), timeout) > 0) {
> +                       dev_err(&client->dev, "wait spi ready timeout\n");
> +                       return -EBUSY;
> +               }
> +
> +               msleep(20);
> +       }
> +
> +       return 0;
> +}
> +
> +static int ps8640_wait_spi_nobusy(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[2];
> +       u8 spi_status, buf[3] = { PAGE2_SWSPI_LEN, 0, TRIGGER_READBACK };
> +       int ret;
> +       ktime_t timeout;
> +
> +       timeout = ktime_add_ms(ktime_get(), 500);
> +       for (;;) {
> +               /* 0x05 RDSR; Read-Status-Register */
> +               ret = ps8640_write_byte(client, PAGE2_SWSPI_WDATA,
> +                                       READ_STATUS_REG_CMD);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               ret = ps8640_write_bytes(client, buf, 3);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               /* delay for cmd send */
> +               usleep_range(300, 500);
> +               /* wait for SPI ROM until not busy */
> +               ret = ps8640_read(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
> +               if (ret)
> +                       goto err_send_cmd_exit;
> +
> +               if (!(spi_status & BUSY))
> +                       break;
> +
> +               if (ktime_compare(ktime_get(), timeout) > 0) {
> +                       dev_err(&client->dev, "wait spi no busy timeout: %d\n",
> +                               ret);
> +                       return -EBUSY;
> +               }
> +       }
> +
> +       return 0;
> +
> +err_send_cmd_exit:
> +       dev_err(&client->dev, "send command err: %d\n", ret);
> +       return ret;
> +}
> +
> +static int ps8640_wait_rom_idle(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       int ret;
> +
> +       ret = ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_wait_spi_ready(ps_bridge);
> +       if (ret)
> +               goto err_spi;
> +
> +       ret = ps8640_wait_spi_nobusy(ps_bridge);
> +       if (ret)
> +               goto err_spi;
> +
> +       ret = ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +       if (ret)
> +               goto exit;
> +
> +       return 0;
> +
> +err_spi:
> +       ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +exit:
> +       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 */
> +       if (ps_bridge->gpio_mode_sel)
> +               gpiod_set_value(ps_bridge->gpio_mode_sel, 0);
> +
> +       /* reset spi interface */
> +       ret = ps8640_write_byte(client, PAGE2_SW_RESET,
> +                               SPI_SW_RESET | MPU_SW_RESET);
> +       if (ret)
> +               goto exit;
> +
> +       ret = ps8640_write_byte(client, PAGE2_SW_RESET, MPU_SW_RESET);
> +       if (ret)
> +               goto exit;
> +
> +       return 0;
> +
> +exit:
> +       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;
> +
> +       cmd[0] = WRITE_ENABLE_CMD;
> +       ret = ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +       if (ret) {
> +               dev_err(dev, "failed enable-write-status-register: %d\n", ret);
> +               return ret;
> +       }
> +
> +       cmd[0] = WRITE_STATUS_REG_CMD;
> +       cmd[1] = CLEAR_ALL_PROTECT;
> +       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_write_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
> +       for (i = 0; i < ARRAY_SIZE(enc_ctrl_code); i++)
> +               ps8640_write_byte(client, PAGE2_ENCTLSPI_WR, enc_ctrl_code[i]);
> +       ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_DISABLE);
> +
> +       /* Enable-Write-Status-Register */
> +       cmd[0] = WRITE_ENABLE_CMD;
> +       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] = CHIP_ERASE_CMD;
> +       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_check_chip_id(struct ps8640 *ps_bridge)
> +{
> +       struct i2c_client *client = ps_bridge->page[4];
> +       u8 buf[4];
> +
> +       ps8640_read(client, PAGE4_REV_L, buf, 4);
> +       return memcmp(buf, hw_chip_id, sizeof(buf));
> +}
> +
> +static int ps8640_validate_firmware(struct ps8640 *ps_bridge,
> +                                   const struct firmware *fw)
> +{
> +       struct i2c_client *client = ps_bridge->page[0];
> +       u16 fw_chip_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 && ps8640_check_chip_id(ps_bridge) == 0) {
> +               dev_err(&client->dev,
> +                       "chip id mismatch: fw 0x%x vs. chip 0x8640\n",
> +                       fw_chip_id);
> +               return -EINVAL;
> +       }
> +
> +       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];
> +       size_t pos, cpy_len;
> +       u8 buf[257];
> +       int ret;
> +
> +       ps8640_write_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
> +       msleep(100);
> +       ps8640_write_byte(client2, PAGE2_SPI_CFG3, 0x00);
> +
> +       for (pos = 0; pos < fw->size; pos += cpy_len) {
> +               buf[0] = PAGE2_ROMADD_BYTE1;
> +               buf[1] = pos >> 8;
> +               buf[2] = pos >> 16;
> +               ret = ps8640_write_bytes(client2, 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_write_bytes(client7, buf, cpy_len + 1);
> +               if (ret)
> +                       goto error;
> +
> +               dev_dbg(dev, "fw update completed %zu / %zu bytes\n", pos,
> +                       fw->size);
> +       }
> +       return 0;
> +
> +error:
> +       dev_err(dev, "failed write external 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] = WRITE_ENABLE_CMD;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 1);
> +
> +       /* protect BPL/BP0/BP1 */
> +       cmd[0] = WRITE_STATUS_REG_CMD;
> +       cmd[1] = BLK_PROTECT_BITS | STATUS_REG_PROTECT;
> +       ps8640_spi_send_cmd(ps_bridge, cmd, 2);
> +
> +       /* wait for SPI rom ready */
> +       ps8640_wait_rom_idle(ps_bridge);
> +
> +       /* disable PS8640 mapping function */
> +       ps8640_write_byte(client, PAGE2_ENCTLSPI_WR, 0x00);
> +
> +       if (ps_bridge->gpio_mode_sel)
> +               gpiod_set_value(ps_bridge->gpio_mode_sel, 1);
> +       return 0;
> +}
> +
> +static int ps8640_enter_bl(struct ps8640 *ps_bridge)
> +{
> +       ps_bridge->in_fw_update = true;
> +       return ps8640_spi_dl_mode(ps_bridge);
> +}
> +
> +static void ps8640_exit_bl(struct ps8640 *ps_bridge, const struct firmware *fw)
> +{
> +       ps8640_spi_normal_mode(ps_bridge);
> +       ps_bridge->in_fw_update = false;
> +}
> +
> +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;
> +
> +       ret = ps8640_validate_firmware(ps_bridge, fw);
> +       if (ret)
> +               return ret;
> +
> +       mutex_lock(&ps_bridge->fw_mutex);
> +       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_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);
> +       mutex_unlock(&ps_bridge->fw_mutex);
> +       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_FW_NAME, dev);
> +       if (error) {
> +               dev_err(dev, "Unable to open firmware %s: %d\n",
> +                       PS_FW_NAME, 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_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_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 ret;
> +       u32 i;
> +
> +       ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> +       if (!ps_bridge)
> +               return -ENOMEM;
> +
> +       /* 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)
> +                       return -EPROBE_DEFER;
> +       }
> +
> +       mutex_init(&ps_bridge->fw_mutex);
> +       ps_bridge->supplies[0].supply = "vdd33";
> +       ps_bridge->supplies[1].supply = "vdd12";
> +       ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
> +                                     ps_bridge->supplies);
> +       if (ret) {
> +               dev_info(dev, "failed to get regulators: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ps_bridge->gpio_mode_sel = devm_gpiod_get_optional(&client->dev,
> +                                                            "mode-sel",
> +                                                            GPIOD_OUT_HIGH);
> +       if (IS_ERR(ps_bridge->gpio_mode_sel)) {
> +               ret = PTR_ERR(ps_bridge->gpio_mode_sel);
> +               dev_err(dev, "cannot get mode-sel %d\n", ret);
> +               return ret;
> +       }
> +
> +       ps_bridge->gpio_power_down = devm_gpiod_get(&client->dev, "sleep",
> +                                              GPIOD_OUT_LOW);
> +       if (IS_ERR(ps_bridge->gpio_power_down)) {
> +               ret = PTR_ERR(ps_bridge->gpio_power_down);
> +               dev_err(dev, "cannot get sleep: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /*
> +        * Request the reset pin low to avoid the bridge being
> +        * initialized prematurely
> +        */
> +       ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",
> +                                              GPIOD_OUT_LOW);
> +       if (IS_ERR(ps_bridge->gpio_reset)) {
> +               ret = PTR_ERR(ps_bridge->gpio_reset);
> +               dev_err(dev, "cannot get reset: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
> +       ps_bridge->bridge.of_node = dev->of_node;
> +
> +       ps_bridge->page[0] = client;
> +       ps_bridge->ddc_i2c = i2c_new_dummy(client->adapter, EDID_I2C_ADDR);
> +       if (!ps_bridge->ddc_i2c) {
> +               dev_err(dev, "failed ddc_i2c dummy device, address%02x\n",
> +                       EDID_I2C_ADDR);
> +               return -EBUSY;
> +       }
> +       /*
> +        * 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 < MAX_DEVS; 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;
> +       }
> +
> +       ret = drm_bridge_add(&ps_bridge->bridge);
> +       if (ret) {
> +               dev_err(dev, "Failed to add bridge: %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:
> +       while (--i)
> +               i2c_unregister_device(ps_bridge->page[i]);
> +       i2c_unregister_device(ps_bridge->ddc_i2c);
> +       return ret;
> +}
> +
> +static int ps8640_remove(struct i2c_client *client)
> +{
> +       struct ps8640 *ps_bridge = i2c_get_clientdata(client);
> +       int i = MAX_DEVS;
> +
> +       drm_bridge_remove(&ps_bridge->bridge);
> +       sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
> +       while (--i)
> +               i2c_unregister_device(ps_bridge->page[i]);
> +
> +       i2c_unregister_device(ps_bridge->ddc_i2c);
> +       return 0;
> +}
> +
> +static const struct i2c_device_id ps8640_i2c_table[] = {
> +       { "parade,ps8640", 0 },

I think that you should remove the manufacturer prefix here, note that
the I2C core removes the manufacturer prefix from the compatible field
so it reports to user-space the uevent: i2c:ps8640, but this doesn't
match with the device id which is parade,ps8640. If you build the
driver as a module will not autoload the driver, to fix this just
remove the manufacturer prefix.

> +       {},

nit: add { /* sentinel */ },

> +};
> +MODULE_DEVICE_TABLE(i2c, ps8640_i2c_table);
> +
> +static const struct of_device_id ps8640_match[] = {
> +       { .compatible = "parade,ps8640" },
> +       {},

nit: add { /* sentinel */ },

> +};
> +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",

Also remove the manufacturer from the name, guess it's more common.

> +               .of_match_table = ps8640_match,
> +       },
> +};
> +module_i2c_driver(ps8640_driver);
> +
> +MODULE_AUTHOR("Jitao Shi <jitao.shi@xxxxxxxxxxxx>");
> +MODULE_AUTHOR("CK Hu <ck.hu@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.9.5
>

A part of these minor things.

Reviewed-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>

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