Hi Marco,
thanks for your patch!
On Wed, Nov 27, 2019 at 12:56 PM Marco Felsch <m.felsch@xxxxxxxxxxxxxx> wrote:
> The DA9062 is a mfd pmic device which supports 5 GPIOs. The GPIOs can
> be used as input, output or have a special use-case.
>
> The patch adds the support for the normal input/output use-case.
>
> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
(...)
> +config PINCTRL_DA9062
> + tristate "Dialog Semiconductor DA9062 PMIC pinctrl and GPIO Support"
> + depends on MFD_DA9062
> + select GPIOLIB
Hm this would be one of those that could use GENERIC_REGMAP_GPIO
the day we invent it but we haven't invented it yet.
> +#include <../gpio/gpiolib.h>
Put a comment above this telling us why you do this thing.
> +static int da9062_gpio_get(struct gpio_chip *gc, unsigned int offset)
> +{
(...)
> + return val & BIT(offset);
You should #include <linux/bits.h> since you use BIT()
Usually I clamp it like this:
return !!(val & BIT(offset));
> +static int da9062_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
> +{
> + struct da9062_pctl *pctl = gpiochip_get_data(gc);
> + struct regmap *regmap = pctl->da9062->regmap;
> + int gpio_mode;
> +
> + gpio_mode = da9062_pctl_get_pin_mode(regmap, offset);
> + if (gpio_mode < 0)
> + return gpio_mode;
> +
> + switch (gpio_mode) {
> + case DA9062_PIN_ALTERNATE:
> + return -ENOTSUPP;
> + case DA9062_PIN_GPI:
> + return 1;
> + case DA9062_PIN_GPO_OD:
> + case DA9062_PIN_GPO_PP:
> + return 0;
We recently added defines for these directions in
<linux/gpio/driver.h>:
#define GPIO_LINE_DIRECTION_IN 1
#define GPIO_LINE_DIRECTION_OUT 0
Please use these. (Soon in Torvald's tree, else
in my "devel" branch.)
> +static int da9062_gpio_direction_input(struct gpio_chip *gc,
> + unsigned int offset)
> +{
> + struct da9062_pctl *pctl = gpiochip_get_data(gc);
> + struct regmap *regmap = pctl->da9062->regmap;
> + struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
> + unsigned int gpi_type;
> + int ret;
> +
> + ret = da9062_pctl_set_pin_mode(regmap, offset, DA9062_PIN_GPI);
> + if (ret)
> + return ret;
> +
> + /*
> + * If the gpio is active low we should set it in hw too. No worries
> + * about gpio_get() because we read and return the gpio-level. So the
> + * gpiolib active_low handling is still correct.
> + *
> + * 0 - active low, 1 - active high
> + */
> + gpi_type = !gpiod_is_active_low(desc);
That's interesting. Correct too, I guess.
> +static int da9062_gpio_direction_output(struct gpio_chip *gc,
> + unsigned int offset, int value)
> +{
> + /* Push-Pull / Open-Drain options are configured during set_config */
> + da9062_gpio_set(gc, offset, value);
That looks dangerous. There is no guarantee that .set_config()
always gets called.
Please create a local state container for the mode of each pin in
struct da9062_pctl and set it to push-pull by default at probe, then
set this to whatever the state is here and let the .set_config()
alter it later if need be.
If we don't do that you will get boot-time defaults I think and that
might create bugs.
> +static int da9062_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
> + unsigned long config)
> +{
(...)
> + case PIN_CONFIG_DRIVE_OPEN_DRAIN:
> + return da9062_pctl_set_pin_mode(regmap, offset,
> + DA9062_PIN_GPO_OD);
> + case PIN_CONFIG_DRIVE_PUSH_PULL:
> + return da9062_pctl_set_pin_mode(regmap, offset,
> + DA9062_PIN_GPO_PP);
So also store this in the per-pin state.
Yours,
Linus Walleij
