[PATCH] ARM: clk: add clk-asm9260 driver
Oleksij Rempel
linux at rempel-privat.de
Thu Jan 15 01:45:32 PST 2015
Am 15.01.2015 um 00:02 schrieb Mike Turquette:
> Quoting Oleksij Rempel (2015-01-08 00:59:27)
>> diff --git a/drivers/clk/clk-asm9260.c b/drivers/clk/clk-asm9260.c
>> new file mode 100644
>> index 0000000..6b1c220
>> --- /dev/null
>> +++ b/drivers/clk/clk-asm9260.c
>
> <snip>
>
>> +static const char *clk_names[] = {
>> + [REFCLK] = "oscillator",
>> + [SYSPLL] = "pll",
>> + [I2S0_MCLK] = "i2s0_mclk",
>> + [I2S1_MCLK] = "i2s1_mclk",
>> + [RTC_OSC] = "rtc_osc",
>> + [USB_PLL] = "usb_pll",
>> +};
>
> Why keep this list of names? Only clk_names[REFCLK] is used below and it
> is overwritten by the name supplied by DT.
Ok.
> <snip>
>
>> +static void __init asm9260_acc_init(struct device_node *np)
>> +{
>> + struct clk *clk;
>> + u32 rate;
>> + int n;
>> + u32 accuracy = 0;
>> +
>> + base = of_io_request_and_map(np, 0, np->name);
>> + if (!base)
>> + panic("%s: unable to map resource", np->name);
>> +
>> + /* register pll */
>> + rate = (ioread32(base + HW_SYSPLLCTRL) & 0xffff) * 1000000;
>> +
>> + clk_names[REFCLK] = of_clk_get_parent_name(np, 0);
>> + accuracy = clk_get_accuracy(__clk_lookup(clk_names[REFCLK]));
>> + clk = clk_register_fixed_rate_with_accuracy(NULL, clk_names[SYSPLL],
>> + clk_names[REFCLK], 0, rate, accuracy);
>
> This is different. Why do the PLLs inherit REFCLKs accuracy? Please see
> __clk_recalc_accuracies in drivers/clk/clk.c if you haven't already. We
> propagate accuracy through the clock tree already.
clk_register_fixed_rate overwrite accuracy to 0. If i use
clk_register_fixed_rate, then half of my clocks has accuracy = 0.
>> +
>> + if (IS_ERR(clk))
>> + panic("%s: can't register REFCLK. Check DT!", np->name);
>> +
<snip>
>> +
>> + /* register clk-provider */
>> + clk_data.clks = clks;
>> + clk_data.clk_num = MAX_CLKS;
>> + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
>> + return;
>> +fail:
>> + iounmap(base);
>> +}
>> +CLK_OF_DECLARE(asm9260_acc, "alphascale,asm9260-clock-controller",
>> + asm9260_acc_init);
>
> Where is the DT binding definition for this clock provider?
>
> Thanks,
> Mike
>
do you mean this patch?
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-October/293147.html
(probably not last version)
Should i resend it to you?
--
Regards,
Oleksij
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