[RFC PATCH] pinctrl-single: Use of pinctrl-single for external device over I2C
vaibhav.hiremath at linaro.org
Mon Jul 6 05:02:37 PDT 2015
On Monday 06 July 2015 12:05 PM, Tony Lindgren wrote:
> * Vaibhav Hiremath <vaibhav.hiremath at linaro.org> [150702 09:58]:
>> --- a/drivers/pinctrl/pinctrl-single.c
>> +++ b/drivers/pinctrl/pinctrl-single.c
>> -static unsigned __maybe_unused pcs_readb(void __iomem *reg)
>> +static unsigned pcs_read(struct regmap *map, unsigned int reg)
>> - return readb(reg);
>> + unsigned int val;
>> -static unsigned __maybe_unused pcs_readw(void __iomem *reg)
>> - return readw(reg);
>> -static unsigned __maybe_unused pcs_readl(void __iomem *reg)
>> - return readl(reg);
>> -static void __maybe_unused pcs_writeb(unsigned val, void __iomem *reg)
>> - writeb(val, reg);
>> + regmap_read(map, reg, &val);
> Sorry this won't work. Most platforms don't need regmap here, and I
> certainly don't want to use regmap for toggling pins for runtime
> PM because of the extra overhead.
That's exactly my question was in my first email. It's ok.
What is your openion on overall code changes for regmap support ?
Any other feedback or suggestions?
> It seems you need to stash the regmap pointer to struct pcs_device
> and just the function pointers. As this driver is ioremapping the
> region, we certainly want to keep things using void __iomem * too.
> You can cast that to whatever regmap needs in the wrapper functions
> for regmap. Note that the extra overhead there won't matter as we
> are using regmap mostly for devices over I2C and so on.
The issue I have here with the signature of read/write fn
static unsigned __maybe_unused pcs_read(void __iomem *reg)
static void __maybe_unused pcs_writeX(unsigned val, void __iomem *reg)
For regmap, I need 2 arguments,
1. Pointer to regmap
2. Offset to register
So I will have to change the signature to
static unsigned __maybe_unused pcs_read(void __iomem *reg, unsigned int
static void __maybe_unused pcs_write(void __iomem *reg, unsigned val,
unsigned int offset)
On the same direction, will having separate functions for regmap.
static unsigned pcs_read_regmap(void __iomem *reg, unsigned int offset)
unsigned int val;
regmap_read((struct regmap *)reg, offset, &val);
static void pcs_write_regmap(void __iomem *reg, unsigned val, unsigned
regmap_write((struct regmap *)reg, offset, val);
This functions will be initialized to pcs_device->read/write.
I will have to do some more changes, specially around pcs_interrupt
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