drm/dsi: Implement set tear scanline

Provide a small convenience wrapper that transmits
a set_tear_scanline command.

v2:
  * helper function suggested by Thierry
    for set_tear_scanline
  * Also includes small build fixes from Sumit Semwal.

v3: one scanline parameter suggested by jani

v4: passing the payload properly as suggested by jani

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>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Vinay Simha BN <simhavcs@gmail.com>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465285532-12676-1-git-send-email-simhavcs@gmail.com

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index f5d8083..7938ce7 100644 (file)
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -983,6 +983,28 @@ 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
+ * @param: STS[10:0]
+ * Return: 0 on success or a negative error code on failure
+ */
+int mipi_dsi_set_tear_scanline(struct mipi_dsi_device *dsi, u16 param)
+{
+       u8 payload[3] = { MIPI_DCS_SET_TEAR_SCANLINE, param >> 8,
+                         param & 0xff };
+       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..ec55285 100644 (file)
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -263,6 +263,7 @@ 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, u16 param);
 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);