[rtc-linux] [PATCH 8/8] ARM: vt8500: gpio: Devicetree support for arch-vt8500
Linus Walleij
linus.walleij at linaro.org
Wed Aug 8 19:11:45 EST 2012
On Wed, Aug 8, 2012 at 3:39 AM, Tony Prisk <linux at prisktech.co.nz> wrote:
> Converted the existing arch-vt8500 gpio to a platform_device.
> Added support for WM8505 and WM8650 GPIO controllers.
(...)
> +++ b/drivers/gpio/gpio-vt8500.c
This driver looks very one-bit-per-gpio typed. Are you sure you cannot
just reuse drivers/gpio/gpio-generic.c? Make a compelling case please...
> +struct vt8500_gpio_bank_regs {
> + int en;
> + int dir;
> + int data_out;
> + int data_in;
Why are all these members int? They should be u8 from reading your code.
> + int ngpio;
> +};
> +static struct vt8500_gpio_data vt8500_data = {
> + .num_banks = 7,
> + .banks = {
> + VT8500_BANK(0x00, 0x20, 0x40, 0x60, 26),
> + VT8500_BANK(0x04, 0x24, 0x44, 0x64, 28),
> + VT8500_BANK(0x08, 0x28, 0x48, 0x68, 31),
> + VT8500_BANK(0x0C, 0x2C, 0x4C, 0x6C, 19),
> + VT8500_BANK(0x10, 0x30, 0x50, 0x70, 19),
> + VT8500_BANK(0x14, 0x34, 0x54, 0x74, 23),
> + VT8500_BANK(-1, 0x3C, 0x5C, 0x7C, 9), /* external gpio */
What on earth are all those magic numbers?
I *guess* they're enabling some default GPIO settings etc.
But it really needs better structure, #defines for each one or
atleast include <linux/bitops.h> and say:
= BIT(4) | /* Enable GPIO pin 5 on this bank */
BIT(5); /* Enable GPIO pin 6 on this bank */
However I suspect this is board specific and should
be taken from device tree. Please elaborate on this...
Ditto for the different instances.
(...)
> + unsigned val;
Looks like all of these should be u8.
> + val = readl(vt8500_chip->base + vt8500_chip->regs->en +
> + vt8500_chip->regoff);
val = (u8) readl(...);
usw
> + val |= (1 << offset);
Use <linux/bitops.h>
val |= BIT(offset);
Apart from these remarks it's looking good...
Yours,
Linus Walleij
More information about the devicetree-discuss
mailing list