[PATCH v2 4/7] tty: serial: support device tree in pxa

Haojian Zhuang haojian.zhuang at gmail.com
Mon Aug 1 12:50:47 EST 2011


On Sat, Jul 30, 2011 at 12:49 AM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Fri, Jul 29, 2011 at 10:45:39AM -0600, Grant Likely wrote:
>> On Thu, Jul 28, 2011 at 02:41:30PM +0800, Haojian Zhuang wrote:
>> > +#ifdef CONFIG_OF
>> > +   for (i = 0; i < PXA_SERIAL_NR; i++) {
>> > +           if (serial_pxa_ports[i] == NULL)
>> > +                   break;
>> > +   }
>> > +   if (i >= PXA_SERIAL_NR) {
>> > +           pr_warn("can't find pxa serial port\n");
>> > +           return -ENODEV;
>> > +   }
>> > +
>> > +   if (of_property_read_u32(np, "clock-frequency", &clk)) {
>> > +           pr_warn("no clock-frequency property set\n");
>> > +           return -ENODEV;
>> > +   }
>> > +   if (of_property_read_u32(np, "current-speed", &spd) == 0)
>> > +           sport->port.custom_divisor = clk / (16 * spd);
>> > +
>> > +   sprintf(name, "pxa2xx-uart.%d", i);
>> > +   sport->clk = clk_get_sys(name, NULL);
>> > +   if (IS_ERR(sport->clk)) {
>> > +           ret = PTR_ERR(sport->clk);
>> > +           goto err_free;
>> > +   }
>> > +   sport->port.uartclk = clk;
>> > +#else
>> > +   i = dev->id;
>> >     sport->clk = clk_get(&dev->dev, NULL);
>> >     if (IS_ERR(sport->clk)) {
>> >             ret = PTR_ERR(sport->clk);
>> >             goto err_free;
>> >     }
>> > +   sport->port.uartclk = clk_get_rate(sport->clk);
>> > +#endif
>>
>> This means a kernel build can either support DT or non-DT, but not
>> both.  DT & non-DT booting are full supported with the same kernel
>> image, so don't do it this way.
>>
>> Instead, check for the presence of an of_node.  If it is there, do the
>> DT parsing.  If now, still support the old method.
>
> Oh ffs, why is this DT stuff causing all the clk stuff to have to change.
> And specifically why is stuff converting to use clk_get_sys().
>
> clk_get_sys() is there to allow system devices to get their clocks.
> It's not for general drivers to use.
>
> Please, stop this madness.
>

So how could I get these clocks?

Thanks
Haojian


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