On Wed, Jun 14, 2023 at 12:07:47PM +0200, Ahmad Fatoum wrote: > From: Marco Felsch <[email protected]> > > The of_xlate function can be used to by drivers which need a other gpio > encoding than: > > gpio = <&phandle gpio-nr gpio-flags>; > > The of_xlate code is as close as possible to the kernel counter part > which makes it easier to add 'struct gpio_desc' support later on. > > Signed-off-by: Marco Felsch <[email protected]> > Reviewed-by: Ahmad Fatoum <[email protected]> > Signed-off-by: Ahmad Fatoum <[email protected]> > --- > v1 -> v2: > - fix typos (Jules) > - forward-declare struct of_phandle_args in header > - use WARN_ON in if condition instead of WARN_ON(1) in body > - use early exits in of_find_gpiochip_by_xlate > --- > drivers/gpio/gpiolib.c | 49 ++++++++++++++++++++++++++++++++++++ > drivers/of/of_gpio.c | 56 +++++++++++++++++++++++++++++++++--------- > include/gpio.h | 26 ++++++++++++++++++++ > 3 files changed, 119 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 5e753d1c7300..f353ce50196c 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -590,6 +590,41 @@ static int of_gpiochip_set_names(struct gpio_chip *chip) > return 0; > } > > +/** > + * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags > + * @gc: pointer to the gpio_chip structure > + * @gpiospec: GPIO specifier as found in the device tree > + * @flags: a flags pointer to fill in > + * > + * This is simple translation function, suitable for the most 1:1 mapped > + * GPIO chips. This function performs only one sanity check: whether GPIO > + * is less than ngpios (that is specified in the gpio_chip). > + */ > +static int of_gpio_simple_xlate(struct gpio_chip *gc, > + const struct of_phandle_args *gpiospec, > + u32 *flags) > +{ > + /* > + * We're discouraging gpio_cells < 2, since that way you'll have to > + * write your own xlate function (that will have to retrieve the GPIO > + * number and the flags from a single gpio cell -- this is possible, > + * but not recommended). > + */ > + if (WARN_ON(gc->of_gpio_n_cells < 2)) > + return -EINVAL; > + > + if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) > + return -EINVAL; > + > + if (gpiospec->args[0] >= gc->ngpio) > + return -EINVAL; > + > + if (flags) > + *flags = gpiospec->args[1]; > + > + return gc->base + gpiospec->args[0]; > +} > + > static int of_gpiochip_add(struct gpio_chip *chip) > { > struct device_node *np; > @@ -599,6 +634,20 @@ static int of_gpiochip_add(struct gpio_chip *chip) > if (!np) > return 0; > > + if (!chip->ops->of_xlate) > + chip->ops->of_xlate = of_gpio_simple_xlate; > + > + /* > + * Separate check since the 'struct gpio_ops' is always the same for > + * every 'struct gpio_chip' of the same instance (e.g. 'struct > + * imx_gpio_chip'). > + */ > + if (chip->ops->of_xlate == of_gpio_simple_xlate) > + chip->of_gpio_n_cells = 2; > + > + if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) > + return -EINVAL; > + > ret = of_gpiochip_set_names(chip); > if (ret) > return ret; > diff --git a/drivers/of/of_gpio.c b/drivers/of/of_gpio.c > index 76398f75422f..7a6435e2296a 100644 > --- a/drivers/of/of_gpio.c > +++ b/drivers/of/of_gpio.c > @@ -46,6 +46,44 @@ static void of_gpio_flags_quirks(struct device_node *np, > > } > > +static struct gpio_chip *of_find_gpiochip_by_xlate( > + struct of_phandle_args *gpiospec) > +{ > + struct gpio_chip *chip; > + struct device *dev; > + > + dev = of_find_device_by_node(gpiospec->np); > + if (!dev) { > + pr_debug("%s: unable to find device of node %pOF\n", > + __func__, gpiospec->np); > + return NULL; > + } > + > + chip = gpio_get_chip_by_dev(dev); > + if (!chip) { > + pr_debug("%s: unable to find gpiochip\n", __func__); > + return NULL; > + } > + > + if (!chip->ops->of_xlate || > + chip->ops->of_xlate(chip, gpiospec, NULL) < 0) { > + pr_err("%s: failed to execute of_xlate\n", __func__); > + return NULL; > + } > + > + return chip; > +} > + > +static int of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, > + struct of_phandle_args *gpiospec, > + enum of_gpio_flags *flags) > +{ > + if (chip->of_gpio_n_cells != gpiospec->args_count) > + return -EINVAL; > + > + return chip->ops->of_xlate(chip, gpiospec, flags); > +} > + > /** > * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO > API > * @np: device node to get GPIO from > @@ -61,7 +99,7 @@ int of_get_named_gpio_flags(struct device_node *np, const > char *propname, > int index, enum of_gpio_flags *flags) > { > struct of_phandle_args gpiospec; > - struct device *dev; > + struct gpio_chip *chip; > int ret; > > ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", > @@ -72,27 +110,21 @@ int of_get_named_gpio_flags(struct device_node *np, > const char *propname, > return ret; > } > > - dev = of_find_device_by_node(gpiospec.np); > - if (!dev) { > - pr_debug("%s: unable to find device of node %s\n", > - __func__, gpiospec.np->full_name); > + chip = of_find_gpiochip_by_xlate(&gpiospec); > + if (!chip) { > ret = -EPROBE_DEFER; > goto out; > } > > - ret = gpio_get_num(dev, gpiospec.args[0]); > - if (ret == -EPROBE_DEFER) > - goto out; > + ret = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags); > if (ret < 0) { > pr_err("%s: unable to get gpio num of device %s: %d\n", > - __func__, dev_name(dev), ret); > + __func__, dev_name(chip->dev), ret); > goto out; > } > > - if (flags) { > - *flags = gpiospec.args[1]; > + if (flags) > of_gpio_flags_quirks(np, propname, flags, index); > - } > > out: > of_node_put(gpiospec.np); > diff --git a/include/gpio.h b/include/gpio.h > index 5f2c16584c3b..9951532084ac 100644 > --- a/include/gpio.h > +++ b/include/gpio.h > @@ -168,6 +168,7 @@ int gpio_array_to_id(const struct gpio *array, size_t > num, u32 *val); > #endif > > struct gpio_chip; > +struct of_phandle_args; > > struct gpio_ops { > int (*request)(struct gpio_chip *chip, unsigned offset); > @@ -177,6 +178,22 @@ struct gpio_ops { > int (*get_direction)(struct gpio_chip *chip, unsigned offset); > int (*get)(struct gpio_chip *chip, unsigned offset); > void (*set)(struct gpio_chip *chip, unsigned offset, int value); > + > +#if defined(CONFIG_OF_GPIO) > + /* > + * If CONFIG_OF_GPIO is enabled, then all GPIO controllers described in > + * the device tree automatically may have an OF translation > + */ > + > + /** > + * @of_xlate: > + * > + * Callback to translate a device tree GPIO specifier into a chip- > + * relative GPIO number and flags. > + */ > + int (*of_xlate)(struct gpio_chip *gc, > + const struct of_phandle_args *gpiospec, u32 *flags); > +#endif > }; > > struct gpio_chip { > @@ -185,6 +202,15 @@ struct gpio_chip { > int base; > int ngpio; > > +#if defined(CONFIG_OF_GPIO) > + /** > + * @of_gpio_n_cells: > + * > + * Number of cells used to form the GPIO specifier. > + */ > + unsigned int of_gpio_n_cells; > +#endif
This patch adds new fields to struct gpio_chip and struct gpio_ops #ifdeffed with CONFIG_OF_GPIO, but the code accessing these fields is not guarded with that #ifdef resulting in compilation failures in several defconfigs like for example animeo_ip_defconfig. I fixed this by adding the missing #ifdefs in the code. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
