Re: [alsa-devel] [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks
On Mon, Feb 17, 2020 at 10:59:55AM +0000, Derek [方德義] wrote:
Subject: Re: [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks
- if (parent_rate != CLK_PLL2_FIN)
dev_warn(component->dev, "clk %s only support %d Hz input\n",clk_name, CLK_PLL2_FIN);
- if (rate != CLK_48) {
dev_warn(component->dev, "clk %s only support %d Hz output\n",clk_name, CLK_48);rate = CLK_48;- }
Are these genuine restrictions of the hardware or is this just being hard coded in the driver?
It's hard coded for an application case. Generate a 48kHz clk with a parent 48 MHz clk.
I see... obviously this is really not good quality of implementation although it doesn't actually break any external interfaces so I guess we could take it. I would at least want to see some clear comments in both the code and the changelog explaining that this limitation is just a temporary hack until a better implementation is done though.
Subject: Re: [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks
On Mon, Feb 17, 2020 at 10:59:55AM +0000, Derek [方德義] wrote:
Subject: Re: [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks
- if (parent_rate != CLK_PLL2_FIN)
dev_warn(component->dev, "clk %s only support %d Hzinput\n",
clk_name, CLK_PLL2_FIN);
- if (rate != CLK_48) {
dev_warn(component->dev, "clk %s only support %d Hzoutput\n",
clk_name, CLK_48);rate = CLK_48;- }
Are these genuine restrictions of the hardware or is this just being hard coded in the driver?
It's hard coded for an application case. Generate a 48kHz clk with a parent 48 MHz clk.
I see... obviously this is really not good quality of implementation although it doesn't actually break any external interfaces so I guess we could take it. I would at least want to see some clear comments in both the code and the changelog explaining that this limitation is just a temporary hack until a better implementation is done though.
Ok. Thanks for the advice. I will add more comments both in the source and commit to clearly describe the driver support and limitation, and then send the PATCH v2.
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participants (2)
-
Derek [方德義] -
Mark Brown