This patch introduces of_pwm_get_index() (and its devm based friend) which works like of_pwm_get() except that you are able to specify which pwm you need instead using a name (which is optional anyway). This comes handy if you have multiple pwms specified in device tree and you need to grab one by one (in a loop) and you don't have any specific names for them.
Signed-off-by: Sebastian Andrzej Siewior <[email protected]> --- drivers/pwm/core.c | 101 +++++++++++++++++++++++++++++++++++++--------------- include/linux/pwm.h | 16 +++++++++ 2 files changed, 88 insertions(+), 29 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 966497d10c6e..f9b679c5d9fa 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -493,35 +493,24 @@ static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) } /** - * of_pwm_get() - request a PWM via the PWM framework + * of_pwm_get_index() - request a PWM via the PWM framework * @np: device node to get the PWM from - * @con_id: consumer name + * @index: The number of the PWN within the property * * Returns the PWM device parsed from the phandle and index specified in the * "pwms" property of a device tree node or a negative error-code on failure. * Values parsed from the device tree are stored in the returned PWM device * object. * - * If con_id is NULL, the first PWM device listed in the "pwms" property will - * be requested. Otherwise the "pwm-names" property is used to do a reverse - * lookup of the PWM index. This also means that the "pwm-names" property - * becomes mandatory for devices that look up the PWM device via the con_id - * parameter. */ -struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) +struct pwm_device *of_pwm_get_index(struct device_node *np, int index) { - struct pwm_device *pwm = NULL; + struct pwm_device *pwm; struct of_phandle_args args; + const char *con_id; struct pwm_chip *pc; - int index = 0; int err; - if (con_id) { - index = of_property_match_string(np, "pwm-names", con_id); - if (index < 0) - return ERR_PTR(index); - } - err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, &args); if (err) { @@ -547,23 +536,47 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) if (IS_ERR(pwm)) goto put; - /* - * If a consumer name was not given, try to look it up from the - * "pwm-names" property if it exists. Otherwise use the name of - * the user device node. - */ - if (!con_id) { - err = of_property_read_string_index(np, "pwm-names", index, - &con_id); - if (err < 0) - con_id = np->name; + err = of_property_read_string_index(np, "pwm-names", index, + &con_id); + if (err < 0) { + con_id = np->name; + pwm->label = con_id; } - - pwm->label = con_id; - put: of_node_put(args.np); + return pwm; +} +EXPORT_SYMBOL_GPL(of_pwm_get_index); +/** + * of_pwm_get() - request a PWM via the PWM framework + * @np: device node to get the PWM from + * @con_id: consumer name + * + * Returns the PWM device parsed from the phandle and index specified in the + * "pwms" property of a device tree node or a negative error-code on failure. + * Values parsed from the device tree are stored in the returned PWM device + * object. + * + * If con_id is NULL, the first PWM device listed in the "pwms" property will + * be requested. Otherwise the "pwm-names" property is used to do a reverse + * lookup of the PWM index. This also means that the "pwm-names" property + * becomes mandatory for devices that look up the PWM device via the con_id + * parameter. + */ +struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) +{ + struct pwm_device *pwm; + int index = 0; + + if (con_id) { + index = of_property_match_string(np, "pwm-names", con_id); + if (index < 0) + return ERR_PTR(index); + } + + pwm = of_pwm_get_index(np, index); + pwm->label = con_id; return pwm; } EXPORT_SYMBOL_GPL(of_pwm_get); @@ -740,6 +753,36 @@ struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) EXPORT_SYMBOL_GPL(devm_pwm_get); /** + * devm_of_pwm_get_index() - resource managed of_pwm_get_index() + * @dev: device for PWM consumer + * @np: device node to get the PWM from + * @index: pwm index + * + * This function performs like of_pwm_get_index() but the acquired PWM device + * will automatically be released on driver detach. + */ +struct pwm_device *devm_of_pwm_get_index(struct device *dev, + struct device_node *np, int index) +{ + struct pwm_device **ptr, *pwm; + + ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + pwm = of_pwm_get_index(np, index); + if (!IS_ERR(pwm)) { + *ptr = pwm; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return pwm; +} +EXPORT_SYMBOL_GPL(devm_of_pwm_get_index); + +/** * devm_of_pwm_get() - resource managed of_pwm_get() * @dev: device for PWM consumer * @np: device node to get the PWM from diff --git a/include/linux/pwm.h b/include/linux/pwm.h index e90628cac8fa..91eb4404bc19 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -192,10 +192,13 @@ struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args); struct pwm_device *pwm_get(struct device *dev, const char *con_id); +struct pwm_device *of_pwm_get_index(struct device_node *np, int index); struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id); void pwm_put(struct pwm_device *pwm); struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id); +struct pwm_device *devm_of_pwm_get_index(struct device *dev, + struct device_node *np, int index); struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, const char *con_id); void devm_pwm_put(struct device *dev, struct pwm_device *pwm); @@ -235,6 +238,12 @@ static inline struct pwm_device *pwm_get(struct device *dev, return ERR_PTR(-ENODEV); } +static inline struct pwm_device *of_pwm_get_index(struct device_node *np, + int index) +{ + return ERR_PTR(-ENODEV); +} + static inline struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) { @@ -251,6 +260,13 @@ static inline struct pwm_device *devm_pwm_get(struct device *dev, return ERR_PTR(-ENODEV); } +static inline struct pwm_device *devm_of_pwm_get_index(struct device *dev, + struct device_node *np, + int index) +{ + return ERR_PTR(-ENODEV); +} + static inline struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, const char *con_id) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
