Re: [PATCH v4 3/6] media: sun6i: Update default CSI_SCLK for A64
From: Jagan Teki <jagan@amarulasolutions.com>
Date: 2018-12-18 15:44:19
Also in:
linux-devicetree, linux-media, lkml
On Tue, Dec 18, 2018 at 8:53 PM Maxime Ripard [off-list ref] wrote:
On Tue, Dec 18, 2018 at 05:03:17PM +0530, Jagan Teki wrote:quoted
Unfortunately A64 CSI cannot work with default CSI_SCLK rate. A64 BSP is using 300MHz clock rate as default csi clock, so sun6i_csi require explicit change to update CSI_SCLK rate to 300MHZ for A64 SoC's. So, set the clk_mod to 300MHz only for A64. Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> --- drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c index 9ff61896e4bb..91470edf7581 100644 --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c@@ -822,6 +822,11 @@ static int sun6i_csi_resource_request(struct sun6i_csi_dev *sdev, return PTR_ERR(sdev->clk_mod); } + /* A64 require 300MHz mod clock to operate properly */ + if (of_device_is_compatible(pdev->dev.of_node, + "allwinner,sun50i-a64-csi")) + clk_set_rate_exclusive(sdev->clk_mod, 300000000); +If you're using clk_set_rate_exclusive, you need to put back the "exclusive" reference once you're not using the clock. Doing it here is not really optimal either, since you'll put a constraint on the system (maintaining that clock at 300MHz), while it's not in use.
I think we can handle via clk_rate_exclusive_put for those errors cases? If I'm not wrong _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel