| Message ID | 1428629325.5384.1.camel@phoenix |
|---|---|
| State | New |
| Headers | show |
Hi Axel, On 4/9/2015 6:28 PM, Axel Lin wrote: > If a gpio is already taken, .gpio_request should return error. Isn't the protection logic already there at the higher layer in gpiolib? Ray > > Signed-off-by: Axel Lin <axel.lin@ingics.com> > --- > drivers/gpio/gpio-bcm-kona.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c > index b164ce8..632352d 100644 > --- a/drivers/gpio/gpio-bcm-kona.c > +++ b/drivers/gpio/gpio-bcm-kona.c > @@ -106,7 +106,7 @@ static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio, > spin_unlock_irqrestore(&kona_gpio->lock, flags); > } > > -static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, > +static int bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, > unsigned gpio) > { > u32 val; > @@ -116,10 +116,17 @@ static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, > spin_lock_irqsave(&kona_gpio->lock, flags); > > val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id)); > + if (!(val & BIT(gpio))) { > + spin_unlock_irqrestore(&kona_gpio->lock, flags); > + return -EBUSY; > + } > + > val &= ~BIT(gpio); > bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val); > > spin_unlock_irqrestore(&kona_gpio->lock, flags); > + > + return 0; > } > > static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) > @@ -185,8 +192,7 @@ static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio) > { > struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip); > > - bcm_kona_gpio_unlock_gpio(kona_gpio, gpio); > - return 0; > + return bcm_kona_gpio_unlock_gpio(kona_gpio, gpio); > } > > static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio) > -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2015-04-11 0:05 GMT+08:00 Ray Jui <rjui@broadcom.com>: > Hi Axel, > > On 4/9/2015 6:28 PM, Axel Lin wrote: >> If a gpio is already taken, .gpio_request should return error. > > Isn't the protection logic already there at the higher layer in gpiolib? OK, you are right. Thanks for the review. Axel -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" 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/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c index b164ce8..632352d 100644 --- a/drivers/gpio/gpio-bcm-kona.c +++ b/drivers/gpio/gpio-bcm-kona.c @@ -106,7 +106,7 @@ static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio, spin_unlock_irqrestore(&kona_gpio->lock, flags); } -static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, +static int bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, unsigned gpio) { u32 val; @@ -116,10 +116,17 @@ static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id)); + if (!(val & BIT(gpio))) { + spin_unlock_irqrestore(&kona_gpio->lock, flags); + return -EBUSY; + } + val &= ~BIT(gpio); bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val); spin_unlock_irqrestore(&kona_gpio->lock, flags); + + return 0; } static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) @@ -185,8 +192,7 @@ static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio) { struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip); - bcm_kona_gpio_unlock_gpio(kona_gpio, gpio); - return 0; + return bcm_kona_gpio_unlock_gpio(kona_gpio, gpio); } static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
If a gpio is already taken, .gpio_request should return error. Signed-off-by: Axel Lin <axel.lin@ingics.com> --- drivers/gpio/gpio-bcm-kona.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)