| Message ID | 1462451666-17945-10-git-send-email-k.kozlowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Krzysztof, On 05/05/2016 08:34 AM, Krzysztof Kozlowski wrote: > Some USB devices on embedded boards have external power supply which has > to be reset in certain conditions. Add pwrseq interface for this. > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > --- > drivers/power/pwrseq/pwrseq.c | 44 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/pwrseq.h | 8 ++++++++ > 2 files changed, 52 insertions(+) > > diff --git a/drivers/power/pwrseq/pwrseq.c b/drivers/power/pwrseq/pwrseq.c > index 495a19d3c30b..306265f55a10 100644 > --- a/drivers/power/pwrseq/pwrseq.c > +++ b/drivers/power/pwrseq/pwrseq.c > @@ -52,6 +52,43 @@ int mmc_pwrseq_alloc(struct mmc_host *host) > } > EXPORT_SYMBOL_GPL(mmc_pwrseq_alloc); > > +struct pwrseq *pwrseq_alloc(struct device *dev) > +{ This function is USB specific so better to call it usb_pwrseq_alloc() instead. Although, this function has a lot of duplicated code from mmc_pwrseq_alloc() so I think is better to keep the name generic and factorize the common code. I expect other devices are also needing some kind of power seq in the future so having a single alloc function instead of each for device type makes sense. > + struct device_node *np; > + struct pwrseq *p, *ret = NULL; > + > + np = of_parse_phandle(dev->of_node, "usb-pwrseq", 0); I know this is just an RFC but you should really add DT bindings for this. Best regards,
On 05/05/2016 09:52 PM, Javier Martinez Canillas wrote: > Hello Krzysztof, > > On 05/05/2016 08:34 AM, Krzysztof Kozlowski wrote: >> Some USB devices on embedded boards have external power supply which has >> to be reset in certain conditions. Add pwrseq interface for this. >> >> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> >> --- >> drivers/power/pwrseq/pwrseq.c | 44 +++++++++++++++++++++++++++++++++++++++++++ >> include/linux/pwrseq.h | 8 ++++++++ >> 2 files changed, 52 insertions(+) >> >> diff --git a/drivers/power/pwrseq/pwrseq.c b/drivers/power/pwrseq/pwrseq.c >> index 495a19d3c30b..306265f55a10 100644 >> --- a/drivers/power/pwrseq/pwrseq.c >> +++ b/drivers/power/pwrseq/pwrseq.c >> @@ -52,6 +52,43 @@ int mmc_pwrseq_alloc(struct mmc_host *host) >> } >> EXPORT_SYMBOL_GPL(mmc_pwrseq_alloc); >> >> +struct pwrseq *pwrseq_alloc(struct device *dev) >> +{ > > This function is USB specific so better to call it usb_pwrseq_alloc() instead. Indeed it is parsing USB specific bindings so such prefix is needed. > Although, this function has a lot of duplicated code from mmc_pwrseq_alloc() > so I think is better to keep the name generic and factorize the common code. > > I expect other devices are also needing some kind of power seq in the future > so having a single alloc function instead of each for device type makes sense. Yes, this can be cleaned up and unified. > >> + struct device_node *np; >> + struct pwrseq *p, *ret = NULL; >> + >> + np = of_parse_phandle(dev->of_node, "usb-pwrseq", 0); > > I know this is just an RFC but you should really add DT bindings for this. Yep, next step. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/power/pwrseq/pwrseq.c b/drivers/power/pwrseq/pwrseq.c index 495a19d3c30b..306265f55a10 100644 --- a/drivers/power/pwrseq/pwrseq.c +++ b/drivers/power/pwrseq/pwrseq.c @@ -52,6 +52,43 @@ int mmc_pwrseq_alloc(struct mmc_host *host) } EXPORT_SYMBOL_GPL(mmc_pwrseq_alloc); +struct pwrseq *pwrseq_alloc(struct device *dev) +{ + struct device_node *np; + struct pwrseq *p, *ret = NULL; + + np = of_parse_phandle(dev->of_node, "usb-pwrseq", 0); + if (!np) + return NULL; + + mutex_lock(&pwrseq_list_mutex); + list_for_each_entry(p, &pwrseq_list, pwrseq_node) { + if (p->dev->of_node == np) { + if (!try_module_get(p->owner)) + dev_err(dev, + "increasing module refcount failed\n"); + else + ret = p; + + break; + } + } + + of_node_put(np); + mutex_unlock(&pwrseq_list_mutex); + + /* FIXME: this path can be simplified... */ + if (!ret) { + dev_info(dev, "usb-pwrseq defer\n"); + return ERR_PTR(-EPROBE_DEFER); + } + + dev_info(dev, "allocated usb-pwrseq\n"); + + return ret; +} +EXPORT_SYMBOL_GPL(pwrseq_alloc); + void pwrseq_pre_power_on(struct pwrseq *pwrseq) { if (pwrseq && pwrseq->ops->pre_power_on) @@ -84,6 +121,13 @@ void mmc_pwrseq_free(struct mmc_host *host) } EXPORT_SYMBOL_GPL(mmc_pwrseq_free); +void pwrseq_free(const struct pwrseq *pwrseq) +{ + if (pwrseq) + module_put(pwrseq->owner); +} +EXPORT_SYMBOL_GPL(pwrseq_free); + int pwrseq_register(struct pwrseq *pwrseq) { if (!pwrseq || !pwrseq->ops || !pwrseq->dev) diff --git a/include/linux/pwrseq.h b/include/linux/pwrseq.h index fcc8fd855d4c..c3c91f50e4cb 100644 --- a/include/linux/pwrseq.h +++ b/include/linux/pwrseq.h @@ -31,9 +31,13 @@ void pwrseq_unregister(struct pwrseq *pwrseq); void pwrseq_pre_power_on(struct pwrseq *pwrseq); void pwrseq_post_power_on(struct pwrseq *pwrseq); void pwrseq_power_off(struct pwrseq *pwrseq); + int mmc_pwrseq_alloc(struct mmc_host *host); void mmc_pwrseq_free(struct mmc_host *host); +struct pwrseq *pwrseq_alloc(struct device *dev); +void pwrseq_free(const struct pwrseq *pwrseq); + #else /* CONFIG_POWER_SEQ */ static inline int pwrseq_register(struct pwrseq *pwrseq) @@ -44,9 +48,13 @@ static inline void pwrseq_unregister(struct pwrseq *pwrseq) {} static inline void pwrseq_pre_power_on(struct pwrseq *pwrseq) {} static inline void pwrseq_post_power_on(struct pwrseq *pwrseq) {} static inline void pwrseq_power_off(struct pwrseq *pwrseq) {} + static inline int mmc_pwrseq_alloc(struct mmc_host *host) { return 0; } static inline void mmc_pwrseq_free(struct mmc_host *host) {} +static inline struct pwrseq *pwrseq_alloc(struct device *dev) { return NULL; } +static inline void pwrseq_free(const struct pwrseq *pwrseq) {} + #endif /* CONFIG_POWER_SEQ */ #endif /* _LINUX_PWRSEQ_H */
Some USB devices on embedded boards have external power supply which has to be reset in certain conditions. Add pwrseq interface for this. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> --- drivers/power/pwrseq/pwrseq.c | 44 +++++++++++++++++++++++++++++++++++++++++++ include/linux/pwrseq.h | 8 ++++++++ 2 files changed, 52 insertions(+)