[PATCH] i2c: sirf: get the i2c pin group by pinctrl api

[Barry Song]

2013/3/18 Sourav Poddar <sourav.poddar at ti.com>:
> Hi,
>
> On Monday 18 March 2013 01:53 PM, Barry Song wrote:
>>
>> 2013/3/18 Sourav Poddar<sourav.poddar at ti.com>:
>>>
>>> Hi,
>>>
>>> On Monday 18 March 2013 12:52 PM, Barry Song wrote:
>>>>
>>>> From: Barry Song<Baohua.Song at csr.com>
>>>>
>>>> hardcode set i2c pin group to i2c function before, here we
>>>> move to use standard pinctrl API to get pins of the group.
>>>>
>>>> Signed-off-by: Barry Song<Baohua.Song at csr.com>
>>>> Cc: Linus Walleij<linus.walleij at linaro.org>
>>>> ---
>>>>    drivers/i2c/busses/i2c-sirf.c |    9 +++++++++
>>>>    1 files changed, 9 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/drivers/i2c/busses/i2c-sirf.c
>>>> b/drivers/i2c/busses/i2c-sirf.c
>>>> index 5a7ad24..dd4004e 100644
>>>> --- a/drivers/i2c/busses/i2c-sirf.c
>>>> +++ b/drivers/i2c/busses/i2c-sirf.c
>>>> @@ -16,6 +16,7 @@
>>>>    #include<linux/clk.h>
>>>>    #include<linux/err.h>
>>>>    #include<linux/io.h>
>>>> +#include<linux/pinctrl/consumer.h>
>>>>
>>>>    #define SIRFSOC_I2C_CLK_CTRL          0x00
>>>>    #define SIRFSOC_I2C_STATUS            0x0C
>>>> @@ -265,6 +266,7 @@ static int i2c_sirfsoc_probe(struct platform_device
>>>> *pdev)
>>>>          struct i2c_adapter *adap;
>>>>          struct resource *mem_res;
>>>>          struct clk *clk;
>>>> +       struct pinctrl *pinctrl;
>>>>          int bitrate;
>>>>          int ctrl_speed;
>>>>          int irq;
>>>> @@ -272,6 +274,12 @@ static int i2c_sirfsoc_probe(struct platform_device
>>>> *pdev)
>>>>          int err;
>>>>          u32 regval;
>>>>
>>>> +       pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
>>>> +       if (IS_ERR(pinctrl)) {
>>>> +               err = PTR_ERR(pinctrl);
>>>> +               goto failed_pin;
>>>> +       }
>>>> +
>>>
>>> I think,  you should also add an "EPROBE_DEFER" check here ?
>>
>> why would the driver require a probe retry since getting the pinctrl
>> has returned an error? before the driver executes, pinctrl driver has
>> run earlier and DT has been extended.
>>
> There might be modules who need some early pinctrl muxing. Some
> drivers might also use subsys_initcall instead of module_init. In such
> cases,
> "EPROBE_DEFER" might be useful.

yes. that is right. here these is no this issue.
in my case, sirf pinctrl is initialized by arch_initcall, i2c probing
is handled by module_init.
that makes i2c is a later user of pinctrl.

>
>> all people are using  IS_ERR(pinctrl) to check the ret of
>> devm_pinctrl_get_select_default.
>>
> Yes, we will keep using this check. DEFER check will be embedded inside
> this.
> Something like below, which has been done for omap i2c..

-barry