Re: [PATCH v3] drm/mediatek: allow commands to be sent during video mode

Il 14/02/22 09:47, Julien STEPHAN ha scritto:

Mipi dsi panel drivers can use mipi_dsi_dcs_{set,get}_display_brightness() to request backlight changes.

This can be done during panel initialization (dsi is in command mode) or afterwards (dsi is in Video Mode).

When the DSI is in Video Mode, all commands are rejected.

Detect current DSI mode in mtk_dsi_host_transfer() and switch modes temporarily to allow commands to be sent.

Signed-off-by: Julien STEPHAN jstephan@baylibre.com Signed-off-by: Mattijs Korpershoek mkorpershoek@baylibre.com

---

Changes in v3: - increase readability of code and use correct return variable (see comment https://lore.kernel.org/linux-mediatek/4907bdc1-b4a6-e9ad-5cfa-266fc20c0bec@...)

Changes in v2: - update commit message to be more descriptive

drivers/gpu/drm/mediatek/mtk_dsi.c | 33 ++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 5d90d2eb0019..7f1b2b7ed3fd 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -891,24 +891,33 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host, u8 read_data[16]; void *src_addr; u8 irq_flag = CMD_DONE_INT_FLAG;

• u32 dsi_mode;
• int ret;

• if (readl(dsi->regs + DSI_MODE_CTRL) & MODE) {

• DRM_ERROR("dsi engine is not command mode\n");
  

• return -EINVAL;
  

• dsi_mode = readl(dsi->regs + DSI_MODE_CTRL);

• if (dsi_mode & MODE) {

• mtk_dsi_stop(dsi);
  

• ret = mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
  

• if (ret)
  

• 	goto restore_dsi_mode;
  

  }

  if (MTK_DSI_HOST_IS_READ(msg->type)) irq_flag |= LPRX_RD_RDY_INT_FLAG;

• if (mtk_dsi_host_send_cmd(dsi, msg, irq_flag) < 0)

• return -ETIME;
  

• ret = mtk_dsi_host_send_cmd(dsi, msg, irq_flag);
• if (ret)

• goto restore_dsi_mode;
  
  

• if (!MTK_DSI_HOST_IS_READ(msg->type))

• return 0;
  

• if (!MTK_DSI_HOST_IS_READ(msg->type)) {

• recv_cnt = 0;
  

• goto restore_dsi_mode;
  

• }

  if (!msg->rx_buf) { DRM_ERROR("dsi receive buffer size may be NULL\n");

• return -EINVAL;
  

• ret = -EINVAL;
  

• goto restore_dsi_mode;
  

  }

  for (i = 0; i < 16; i++)

@@ -933,7 +942,13 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host, DRM_INFO("dsi get %d byte data from the panel address(0x%x)\n", recv_cnt, *((u8 *)(msg->tx_buf)));

• return recv_cnt;

+restore_dsi_mode:

• if (dsi_mode & MODE) {

• mtk_dsi_set_mode(dsi);
  

• mtk_dsi_start(dsi);
  

• }
• return ret < 0 ? ret: recv_cnt;

Nitpick: you've missed a space ... ret : recv_cnt;

With that fixed,

Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com

}

static const struct mipi_dsi_host_ops mtk_dsi_ops = {

2.35.1