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author | Daniel Mentz <danielmentz@google.com> | 2023-01-17 01:49:07 +0300 |
---|---|---|
committer | Neil Armstrong <neil.armstrong@linaro.org> | 2023-01-19 10:21:56 +0300 |
commit | c9d27c6be518b4ef2966d9564654ef99292ea1b3 (patch) | |
tree | b769f4c4a7dda23e06df6ee7efc9d624327cd195 /drivers/gpu/drm/drm_mipi_dsi.c | |
parent | 13acb368bf02c4ab2c3bd7c35629b421b0ceed18 (diff) | |
download | linux-c9d27c6be518b4ef2966d9564654ef99292ea1b3.tar.xz |
drm/mipi-dsi: Fix byte order of 16-bit DCS set/get brightness
The MIPI DCS specification demands that brightness values are sent in
big endian byte order. It also states that one parameter (i.e. one byte)
shall be sent/received for 8 bit wide values, and two parameters shall
be used for values that are between 9 and 16 bits wide.
Add new functions to properly handle 16-bit brightness in big endian,
since the two 8- and 16-bit cases are distinct from each other.
[richard: use separate functions instead of switch/case]
[richard: split into 16-bit component]
Fixes: 1a9d759331b8 ("drm/dsi: Implement DCS set/get display brightness")
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Link: https://android.googlesource.com/kernel/msm/+/754affd62d0ee268c686c53169b1dbb7deac8550
[richard: fix 16-bit brightness_get]
Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Tested-by: Caleb Connolly <caleb@connolly.tech>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230116224909.23884-2-mailingradian@gmail.com
Diffstat (limited to 'drivers/gpu/drm/drm_mipi_dsi.c')
-rw-r--r-- | drivers/gpu/drm/drm_mipi_dsi.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 497ef4b6a90a..4bc15fbd009d 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -1224,6 +1224,58 @@ int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness); +/** + * mipi_dsi_dcs_set_display_brightness_large() - sets the 16-bit brightness value + * of the display + * @dsi: DSI peripheral device + * @brightness: brightness value + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_set_display_brightness_large(struct mipi_dsi_device *dsi, + u16 brightness) +{ + u8 payload[2] = { brightness >> 8, brightness & 0xff }; + ssize_t err; + + err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, + payload, sizeof(payload)); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness_large); + +/** + * mipi_dsi_dcs_get_display_brightness_large() - gets the current 16-bit + * brightness value of the display + * @dsi: DSI peripheral device + * @brightness: brightness value + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, + u16 *brightness) +{ + u8 brightness_be[2]; + ssize_t err; + + err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, + brightness_be, sizeof(brightness_be)); + if (err <= 0) { + if (err == 0) + err = -ENODATA; + + return err; + } + + *brightness = (brightness_be[0] << 8) | brightness_be[1]; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness_large); + static int mipi_dsi_drv_probe(struct device *dev) { struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver); |