Re: [PATCH v11 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

Hi Jitao,

Getting very close now...

Comments inline...

On Tue, Feb 23, 2016 at 3:35 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 v10:

• Tuning PS8640 reset sleep pins squence

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

https://patchwork.kernel.org/patch/8289181/ ("drm/dsi: check for CONFIG_OF when defining") https://patchwork.kernel.org/patch/8289051/ ("drm/dsi: Use mipi_dsi_device_register_full for DSI device") https://patchwork.kernel.org/patch/8289081/ ("drm/dsi: Try to match non-DT DSI devices") https://patchwork.kernel.org/patch/8289121/ ("drm/dsi: Add routine to unregister a DSI device") https://patchwork.kernel.org/patch/8289091/ ("drm/dsi: Get DSI host by DT device node")

---

drivers/gpu/drm/bridge/Kconfig | 11 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/parade-ps8640.c | 1060 ++++++++++++++++++++++++++++++++ 3 files changed, 1072 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..b4edd8c 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -40,4 +40,15 @@ 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
  

To remove the cyclic dependency on I2C, remove the I2C, and replace with:

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
  

endmenu

[snip]

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c new file mode 100644 index 0000000..d7410df --- /dev/null +++ b/drivers/gpu/drm/bridge/parade-ps8640.c

[snip]

+static int ps8640_write_bytes(struct i2c_client *client, u8 *data,

•                         u16 data_len)
  

const u8 *data

+{

•   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_write_byte(struct i2c_client *client, u8 reg, u8 data)

nit: (extra space before "u8 data".

Also, just reuse ps8640_write_bytes, so like this:

static int ps8640_write_byte(struct i2c_client *client, u8 reg, u8 data) { u8 buf[] = {reg, data}; return ps8640_write_bytes(client, buf, 2); }

+{

•   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;
  

+}

[snip]

+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;
  

•   }
  

•   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_slp_n, 1);
  

•   gpiod_set_value(ps_bridge->gpio_rst_n, 0);
  

•   usleep_range(2000, 2500);
  

•   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_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;
  

•           }
  

•           msleep(20);
  

This wastes 20 ms on success. Use the routines in <linux/iopoll.h> for polling loops like this.

•   } 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_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);
  

+}

[snip]

+static int ps8640_get_modes(struct drm_connector *connector) +{

•   struct ps8640 *ps_bridge = connector_to_ps8640(connector);
  

•   struct device *dev = &ps_bridge->page[0]->dev;
  

•   u8 *edid;
  

•   int ret, 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 = devm_kmalloc(dev, EDID_LENGTH, GFP_KERNEL);
  

•   if (!edid) {
  

•           DRM_ERROR("Failed to allocate EDID\n");
  

•           return 0;
  

•   }
  

•   ret = ps8640_read(ps_bridge->ddc_i2c, 0, edid, EDID_LENGTH);
  

•   if (ret)
  

•           goto out;
  

•   ps_bridge->edid = (struct 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;
  

•   ps_bridge = connector_to_ps8640(connector);
  

nit: struct ps8640 *ps_bridge = connector_to_ps8640(connector);

•   return ps_bridge->bridge.encoder;
  

+}

[snip]

+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;
  

Missing drm_panel_detach on error Missing drm_connector_unregister/drm_connector_cleanup on error

•   }
  

•   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;
  

Missing drm_connector_unregister/drm_connector_cleanup on error

•   }
  

•   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.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, buf[3];
  

•   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;
  

Still do IROM_DISABLE on failure?

•   }
  

•   buf[0] = PAGE2_SWSPI_LEN;
  

•   buf[1] = cmd_len - 1;
  

•   buf[2] = TRIGGER_NO_READBACK;
  

•   ret = ps8640_write_bytes(client, buf, 3);
  

•   if (ret)
  

•           goto err;
  

Still do IROM_DISABLE on failure?

•   ret = ps8640_write_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_read(client, PAGE2_SPI_STATUS, &spi_rdy_st, 1);
  

•           msleep(20);
  

This wastes 20 ms on success. Use the routines in <linux/iopoll.h> for polling loops like this.

•           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, buf[3], retry_cnt = 0;
  

•   int ret;
  

•   do {
  

•           /* 0x05 RDSR; Read-Status-Register */
  

•           ret = ps8640_write_byte(client, PAGE2_SWSPI_WDATA,
  

•                                   READ_STATUS_REG_CMD);
  

•           if (ret)
  

•                   goto err_send_cmd_exit;
  

•           buf[0] = PAGE2_SWSPI_LEN;
  

•           buf[1] = 0;
  

•           buf[2] = TRIGGER_READBACK;
  

•           ret = ps8640_write_bytes(client, buf, 3);
  

•           if (ret)
  

•                   goto err_send_cmd_exit;
  

•           /* delay for cmd send */
  

•           usleep_range(100, 300);
  

•           /* wait for SPI ROM until not busy */
  

•           ret = ps8640_read(client, PAGE2_SWSPI_RDATA, &spi_status, 1);
  

•           if (ret)
  

•                   goto err_send_cmd_exit;
  

•   } while ((retry_cnt++ < SPI_MAX_RETRY_CNT) &&
  

•            (spi_status & BLK_PROTECT_BITS) == BLK_PROTECT_BITS);
  

•   if ((retry_cnt > SPI_MAX_RETRY_CNT) &&
  

•       (spi_status & BLK_PROTECT_BITS) != BLK_PROTECT_BITS) {
  

•           ret = -EBUSY;
  

•           dev_err(&client->dev, "wait spi no busy timeout: %d\n", ret);
  

•           goto err_timeout;
  

just "return -EBUSY".

•   }
  

•   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_write_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)
  

If either ready/nobusy fail, should we still do IROM_DISABLE?

•           goto exit;
  

•   ret = ps8640_write_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_write_byte(client, PAGE2_SW_REST,
  

•                           SPI_SW_RESET | MPU_SW_RESET);
  

•   if (ret)
  

•           goto exit;
  

•   ret = ps8640_write_byte(client, PAGE2_SW_REST, MPU_SW_RESET);
  

•   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;
  

•   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);
  

If this fails, should we undo "WRITE_ENABLE_CMD" and/or "CLEAR_ALL_PROTECT" above?

•           return ret;
  

•   }
  

•   ps8640_write_byte(client, PAGE2_IROM_CTRL, IROM_ENABLE);
  

•   for (i = 0; i < 6; 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_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) {
  

Shouldn't we be comparing to something read from the device rather than a hard-coded value? Perhaps (info->family_id, info->variant_id)?

•           dev_err(&client->dev,
  

•                   "chip id mismatch: fw 0x%x vs. chip 0x8640\n",
  

•                   fw_chip_id);
  

•           return -ENODEV;
  

This error means that the firmware file provided by userspace is invalid, so: return -EINVAL;

•   }
  

•   fw_version_id = get_unaligned_le16(fw->data + FW_VERSION_OFFSET);
  

•   if (fw_version_id == info->version) {
  

•           dev_err(&client->dev,
  

•                   "no need update fw version same: fw %d.%d vs. chip %d.%d\n",
  

•                   fw_version_id >> 8, fw_version_id & 0xff,
  

•                   info->version >> 8, info->version & 0xff);
  

•           return -ENODEV;
  

This is not an error. Just return 0. Or, perhaps just remove this check and just allow userspace to re-write the same version. There are cases where this is valid: (a) to test firmware update (b) b/c userspace doesn't trust the old firmware despite what version it reports (c) b/c of suspected flash corruption, etc. Anyway, this is 'policy', and shouldn't be handled here in the kernel driver.

•   }
  

•   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_write_byte(client2, PAGE2_SPI_CFG3, I2C_TO_SPI_RESET);
  

•   msleep(100);
  

•   ps8640_write_byte(client2, PAGE2_SPI_CFG3, 0x00);
  

•   while (pos < fw->size) {
  

style nit: This 'while' would work better as a for loop:

for (pos = 0; pos < fw->size; pos += cpy_len)

•           rom_page_id_buf[0] = PAGE2_ROMADD_BYTE1;
  

•           rom_page_id_buf[1] = (pos >> 8) & 0xff;
  

•           rom_page_id_buf[2] = (pos >> 16) & 0xff;
  

Remove "& 0xff" from the two lines above b/c rom_page_id_buf[] is a u8 array.

•           ret = ps8640_write_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_write_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] = 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);
  

•   gpiod_set_value(ps_bridge->gpio_mode_sel_n, 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;
  

•   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);
  

ps8640_validate_firmware() does not depend on the device at all; do this check before switching to "bootloader" mode.

•   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_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 i, ret;
  

•   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;
  

•   }
  

•   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 -EPROBE_DEFER;
  

return ret

•   }
  

•   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 mode-sel %d\n", ret);
  

•           return ret;
  

•   }
  

•   ps_bridge->gpio_slp_n = devm_gpiod_get(&client->dev, "sleep",
  

•                                          GPIOD_OUT_LOW);
  

•   if (IS_ERR(ps_bridge->gpio_slp_n)) {
  

•           ret = PTR_ERR(ps_bridge->gpio_slp_n);
  

•           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_rst_n = devm_gpiod_get(&client->dev, "reset",
  

•                                          GPIOD_OUT_LOW);
  

•   if (IS_ERR(ps_bridge->gpio_rst_n)) {
  

•           ret = PTR_ERR(ps_bridge->gpio_rst_n);
  

•           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;
  

•   ret = drm_bridge_add(&ps_bridge->bridge);
  

•   if (ret) {
  

•           dev_err(dev, "Failed to add bridge: %d\n", ret);
  

•           return ret;
  

•   }
  

•   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);
  

•           ret = -EBUSY;
  

•           goto exit_ddc_i2c_dummy;
  

•   }
  

•   /*
  

•    * 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]);
  

i2c_unregister_device(ps_bridge->ddc_i2c);

+exit_ddc_i2c_dummy:

•   drm_bridge_remove(&ps_bridge->bridge);
  

•   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]);
  

i2c_unregister_device(ps_bridge->ddc_i2c);

Ok, that's it for this round. Thanks!

-Dan

•   drm_bridge_remove(&ps_bridge->bridge);
  

•   return 0;
  

+}