On 4/22/22 2:39 AM, Tommaso Merciai wrote:
On Thu, Apr 21, 2022 at 08:09:59PM -0400, Sean Anderson wrote:
On 4/21/22 2:48 AM, Tommaso Merciai wrote:
Hi,
I'm working on drivers/clk/imx/clk-imx8mm.c to port and bring up eLCDIF
clocks. After port all necessary clocks needed by eLCDIF I found that
IMX8MM_VIDEO_PLL1 clock is not enabled and need the following code to enable
it at the end of the clk-imx8mm probe:

struct clk *clkp;

clk_get_by_id(IMX8MM_VIDEO_PLL1, &clkp);
clk_set_rate(clkp, 594000000UL);
clk_enable(clkp);

What do you think about this solution?
There is a more standard way to do this?

PLL1 should be a parent of one of the clocks required by the eLCDIF. That clock
should call clk_enable() on PLL1 when it is enabled itself. If you want to set
a specific rate, you can do that with assigned-clock-rates in either the clock's
DT node, or the eLCDIF's DT node.

Hi Sean,
Thanks for your suggestion, I need only to enable it, I have already
assign the right rate from dts. The doubt at this point is: it's right call 
clk_enable
from clk-imx8mm.c? I think yes because it handle by "fsl,imx8mm-ccm"
driver, maybe protected by CONFIG_DM_VIDEO could be a good solution.
Let me know.

I don't think so. Generally whatever uses the clock (e.g. your video driver) 
will call
clk_enable, and CCF should propegate that enable up the clock tree.

--Sean

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