On Tue, Sep 17, 2019 at 2:45 AM Stephen Boyd [off-list ref] wrote:

Quoting Dong Aisheng (2019-09-09 04:23:14)

quoted

]On Sat, Sep 7, 2019 at 5:35 PM Stephen Boyd [off-list ref] wrote:

quoted

Quoting Dong Aisheng (2019-08-20 04:13:22)

quoted

Add parsing clocks from device tree.

Please describe some more here.

Will improve.

quoted

quoted

+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(base))
+               return PTR_ERR(base);
+
+       count = of_property_count_u32_elems(np, "clock-indices");
+       if (count < 0) {
+               dev_err(&pdev->dev, "failed to count clocks\n");
+               return -EINVAL;
+       }

Is 'count' expected to be equal to IMX_LPCG_MAX_CLKS? Because later on
in this function we set the num of clks to the MAX instead of the count
from clock-indices.

No. Here is a tricky to ease the clk getting.
For example, one LPCG supports up to 8 clock outputs which each of them
is fixed to 4 bits. Then we can easily use the bit-offset/clk-indices
parsed from DT
to fetch the corresponding clock by hws[clkspec->args[0] / 4].
And the cost is very limited with only a few pointers.

Ok. Can you add a comment into the code to explain this?

Yes, added.
Thanks for the good suggestion.

Regards
Aisheng

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel