Provide a small convenience wrapper that set/get the backlight brightness control and creates the backlight device for the panel interface

Cc: John Stultz john.stultz@linaro.org Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Archit Taneja archit.taneja@gmail.com Cc: Rob Clark robdclark@gmail.com Signed-off-by: Vinay Simha BN simhavcs@gmail.com

-- v1: *tested in nexus7 2nd gen. --- drivers/gpu/drm/drm_mipi_dsi.c | 63 ++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 3 ++ 2 files changed, 66 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 2f0b85c..ac4521e 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -1026,6 +1026,69 @@ int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format) } EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);

+static int dsi_dcs_bl_get_brightness(struct backlight_device *bl) +{ + struct mipi_dsi_device *dsi = bl_get_data(bl); + int ret; + u8 brightness; + + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM; + + ret = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, + &brightness, sizeof(brightness)); + if (ret < 0) + return ret; + + dsi->mode_flags |= MIPI_DSI_MODE_LPM; + + return brightness; +} + +static int dsi_dcs_bl_update_status(struct backlight_device *bl) +{ + struct mipi_dsi_device *dsi = bl_get_data(bl); + int ret; + u8 brightness = bl->props.brightness; + + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM; + + ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, + &brightness, sizeof(brightness)); + if (ret < 0) + return ret; + + dsi->mode_flags |= MIPI_DSI_MODE_LPM; + + return 0; +} + +static const struct backlight_ops dsi_bl_ops = { + .update_status = dsi_dcs_bl_update_status, + .get_brightness = dsi_dcs_bl_get_brightness, +}; + +/** + * drm_panel_create_dsi_backlight() - creates the backlight device for the panel + * @dsi: DSI peripheral device + * + * @return a struct backlight on success, or an ERR_PTR on error + */ +struct backlight_device + *drm_panel_create_dsi_backlight(struct mipi_dsi_device *dsi) +{ + struct device *dev = &dsi->dev; + struct backlight_properties props; + + memset(&props, 0, sizeof(props)); + props.type = BACKLIGHT_RAW; + props.brightness = 255; + props.max_brightness = 255; + + return devm_backlight_device_register(dev, dev_name(dev), dev, dsi, + &dsi_bl_ops, &props); +} +EXPORT_SYMBOL(drm_panel_create_dsi_backlight); + static int mipi_dsi_drv_probe(struct device *dev) { struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver); diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 2788dbe..9dd6a97 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -12,6 +12,7 @@ #ifndef __DRM_MIPI_DSI_H__ #define __DRM_MIPI_DSI_H__

+#include <linux/backlight.h> #include <linux/device.h>

struct mipi_dsi_host; @@ -269,6 +270,8 @@ int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi); int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi, enum mipi_dsi_dcs_tear_mode mode); int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format); +struct backlight_device + *drm_panel_create_dsi_backlight(struct mipi_dsi_device *dsi);

/** * struct mipi_dsi_driver - DSI driver

On Thu, 02 Jun 2016, Vinay Simha BN simhavcs@gmail.com wrote:

Provide a small convenience wrapper that transmits ia set_tear_scanline command as suggested by Thierry Reding.

Also includes small build fixes from Sumit Semwal.

Cc: Archit Taneja archit.taneja@gmail.com Cc: John Stultz john.stultz@linaro.org Cc: Thierry Reding thierry.reding@gmail.com Cc: Sumit Semwal sumit.semwal@linaro.org Signed-off-by: Vinay Simha BN simhavcs@gmail.com

---

drivers/gpu/drm/drm_mipi_dsi.c | 23 +++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 2 ++ 2 files changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index f5d8083..2f0b85c 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -983,6 +983,29 @@ int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi, EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_on);

/**

• • mipi_dsi_set_tear_scanline() - turn on the display module's Tearing Effect
• • output signal on the TE signal line when display module reaches line N
• • defined by STS[n:0].
• • @dsi: DSI peripheral device
• • @param1: STS[10:8]
• • @param2: STS[7:0]
• • Return: 0 on success or a negative error code on failure
• */

+int mipi_dsi_set_tear_scanline(struct mipi_dsi_device *dsi,

• 	       u8 param1, u8 param2)
  

If you're making a helper, please make using it easy and have *one* scanline parameter.

BR, Jani.

+{

• u8 payload[3] = { MIPI_DCS_SET_TEAR_SCANLINE, param1, param2};
• ssize_t err;
• err = mipi_dsi_generic_write(dsi, &payload, sizeof(payload));
• if (err < 0)

• return err;
  

• return 0;

+} +EXPORT_SYMBOL(mipi_dsi_set_tear_scanline);

+/**

• mipi_dsi_dcs_set_pixel_format() - sets the pixel format for the RGB image
• data used by the interface
• @dsi: DSI peripheral device

diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 7a9840f..2788dbe 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -263,6 +263,8 @@ int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start, u16 end); int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start, u16 end); +int mipi_dsi_set_tear_scanline(struct mipi_dsi_device *dsi, u8 param1,

• 	       u8 param2);
  

int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi); int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi, enum mipi_dsi_dcs_tear_mode mode);