On Thu, Sep 27, 2018 at 6:13 PM Chen-Yu Tsai [off-list ref] wrote:

Hi,

On Thu, Sep 27, 2018 at 7:49 PM Jagan Teki [off-list ref] wrote:

quoted

DSI bus_clk is already available in sun6i_dsi but missed to
get the clk and process for enable/disable.

This patch add support for it.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 8e9c76febca2..156b371243c6 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c

@@ -1004,6 +1004,12 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
                return PTR_ERR(dsi->reset);
        }

+       dsi->bus_clk = devm_clk_get(dev, "bus");
+       if (IS_ERR(dsi->bus_clk)) {
+               dev_err(dev, "Couldn't get the DSI bus clock\n");
+               return PTR_ERR(dsi->bus_clk);
+       }
+

The DSI driver uses devm_regmap_init_mmio_clk, which enables the
clock behind the scenes when regmap access needs it enabled.

Did you have any issues without this patch?

I'm unable to read register values via devmem, I see all 0's for all
dsi reg space.