pinctrl: Add pinctrl-s3c24xx driver

Hello Heiko Stuebner,

The patch af99a7507469: "pinctrl: Add pinctrl-s3c24xx driver" from May 21, 2013, leads to the following static checker warning:

	drivers/pinctrl/samsung/pinctrl-s3c24xx.c:188 s3c24xx_eint_type()
	warn: are you sure the precedence is correct here?

drivers/pinctrl/samsung/pinctrl-s3c24xx.c

   186          /* Set up interrupt trigger */
   187          reg = d->virt_base + EINT_REG(index);
   188          shift = EINT_OFFS(index);

189

EINT_OFFS() is defined with two different precedences. One of them is probably wrong and it's probably this one here that does the MOD operation first followed by the multiply.

#define EINT_OFFS(i) ((i) % EINT_MAX_PER_GROUP * 4) #define EINT_OFFS(i) ((i) % (2 * EINT_MAX_PER_GROUP))

regards,
dan carpenter

Hi Dan,

Am Donnerstag, 31. Juli 2014, 13:39:36 schrieb Dan Carpenter:

I suppose the other EINT_OFFS definition

	((i) % (2 * EINT_MAX_PER_GROUP))

is from pinctrl-64xx.c, right?

On the s3c24xx, the eints are arranged in a set of registers:
eint0 bits [2:0]
eint1 bits [6:4]
...
eint7 bits [30:28]

(next register):
eint8 bits [2:0]
...
eint15 bits [30:28]
...

EINT_MAX_PER_GROUP is of course 8, so for example eint15 % 8 = 7
7 * 4 = 28 ... the correct bit offset in the register.

The eint layout on the s3c64xx is slightly different, so the offset calculation is likely too.

Heiko