On Mon, Dec 18, 2017 at 09:27:16AM +0530, Subhransu S. Prusty wrote:
On Wed, Dec 13, 2017 at 02:30:32PM -0800, Stephen Boyd wrote:
On 12/11, Sriram Periyasamy wrote:
+static int skl_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)+{
- struct skl_clk *clkdev = to_skl_clk(hw);
- struct skl_clk_rate_cfg_table *rcfg;
- int clk_type;
- if (!clkdev)
return -ENODEV;These checks don't make sense. container_of() on clk_hw structures returning NULL wouldn't happen.
Sure. will remove.
- if (!rate)
return -EINVAL;- if (__clk_is_enabled(hw->clk) && (clkdev->rate != rate))
Any chance you can directly read the hardware instead of going through the framework to find out if the clk is enabled? Seems
No. This involves sending an IPC to DSP to enable clock and interpreting the return error code. I would like to avoid doing this here in set_rate.
circular to do it this way.
return -EBUSY;- rcfg = skl_get_rate_cfg(clkdev->pdata->ssp_clks[clkdev->id].rate_cfg,
rate);- if (!rcfg)
return -EINVAL;- clk_type = skl_get_clk_type(clkdev->id);
- if (clk_type < 0)
return clk_type;- skl_fill_clk_ipc(rcfg, clk_type);
- clkdev->rate = rate;
- return 0;
+}
+static unsigned long skl_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)+{
- struct skl_clk *clkdev = to_skl_clk(hw);
- struct skl_clk_rate_cfg_table *rcfg;
- int clk_type;
- if (!clkdev)
return 0;- if (clkdev->rate)
return clkdev->rate;Why is the rate being cached? We should always be able to calculate the rate based on parent_rate that gets passed to this function?
Will check and get back.
If I understand correctly, you refer to deriving the rate from parent_rate using ratios. But since only the DSP is aware of the ratios and not the driver, the driver can't derive the rate from the parent_rate and thus cached.
Regards, Subhransu
- rcfg = skl_get_rate_cfg(clkdev->pdata->ssp_clks[clkdev->id].rate_cfg,
parent_rate);- if (!rcfg)
return 0;- clk_type = skl_get_clk_type(clkdev->id);
- if (clk_type < 0)
return 0;- skl_fill_clk_ipc(rcfg, clk_type);
- clkdev->rate = rcfg->rate;
- return clkdev->rate;
+}
+/* Not supported by clk driver. Implemented to satisfy clk fw */ +long skl_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)+{
- return rate;
+}
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