| Message ID | 1399649837-27286-1-git-send-email-balajitk@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Friday 09 May 2014 09:07 PM, Balaji T K wrote: > Provide an option to get CD debounce time from DT > > Signed-off-by: Balaji T K <balajitk@ti.com> Hi Chris/Ulf, Any comments on this patch ? > --- > Documentation/devicetree/bindings/mmc/mmc.txt | 1 + > drivers/mmc/core/host.c | 6 +++++- > 2 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt > index 9dce540..fae590b 100644 > --- a/Documentation/devicetree/bindings/mmc/mmc.txt > +++ b/Documentation/devicetree/bindings/mmc/mmc.txt > @@ -17,6 +17,7 @@ Optional properties: > - bus-width: Number of data lines, can be <1>, <4>, or <8>. The default > will be <1> if the property is absent. > - wp-gpios: Specify GPIOs for write protection, see gpio binding > +- cd-debounce-us: debounce time in microseconds for card detect gpio. > - cd-inverted: when present, polarity on the CD line is inverted. See the note > below for the case, when a GPIO is used for the CD line > - wp-inverted: when present, polarity on the WP line is inverted. See the note > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index fdea825..59cd3a0 100644 > --- a/drivers/mmc/core/host.c > +++ b/drivers/mmc/core/host.c > @@ -313,6 +313,7 @@ int mmc_of_parse(struct mmc_host *host) > bool explicit_inv_wp, gpio_inv_wp = false; > enum of_gpio_flags flags; > int len, ret, gpio; > + unsigned int debounce; > > if (!host->parent || !host->parent->of_node) > return 0; > @@ -367,6 +368,9 @@ int mmc_of_parse(struct mmc_host *host) > if (of_find_property(np, "broken-cd", &len)) > host->caps |= MMC_CAP_NEEDS_POLL; > > + if (of_property_read_u32(np, "cd-debounce-us", &debounce) < 0) > + debounce = 0; > + > gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags); > if (gpio == -EPROBE_DEFER) > return gpio; > @@ -374,7 +378,7 @@ int mmc_of_parse(struct mmc_host *host) > if (!(flags & OF_GPIO_ACTIVE_LOW)) > gpio_inv_cd = true; > > - ret = mmc_gpio_request_cd(host, gpio, 0); > + ret = mmc_gpio_request_cd(host, gpio, debounce); > if (ret < 0) { > dev_err(host->parent, > "Failed to request CD GPIO #%d: %d!\n", > -- 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
On 9 May 2014 17:37, Balaji T K <balajitk@ti.com> wrote: > Provide an option to get CD debounce time from DT > > Signed-off-by: Balaji T K <balajitk@ti.com> > --- > Documentation/devicetree/bindings/mmc/mmc.txt | 1 + > drivers/mmc/core/host.c | 6 +++++- > 2 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt > index 9dce540..fae590b 100644 > --- a/Documentation/devicetree/bindings/mmc/mmc.txt > +++ b/Documentation/devicetree/bindings/mmc/mmc.txt > @@ -17,6 +17,7 @@ Optional properties: > - bus-width: Number of data lines, can be <1>, <4>, or <8>. The default > will be <1> if the property is absent. > - wp-gpios: Specify GPIOs for write protection, see gpio binding > +- cd-debounce-us: debounce time in microseconds for card detect gpio. > - cd-inverted: when present, polarity on the CD line is inverted. See the note > below for the case, when a GPIO is used for the CD line > - wp-inverted: when present, polarity on the WP line is inverted. See the note > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index fdea825..59cd3a0 100644 > --- a/drivers/mmc/core/host.c > +++ b/drivers/mmc/core/host.c > @@ -313,6 +313,7 @@ int mmc_of_parse(struct mmc_host *host) > bool explicit_inv_wp, gpio_inv_wp = false; > enum of_gpio_flags flags; > int len, ret, gpio; > + unsigned int debounce; > > if (!host->parent || !host->parent->of_node) > return 0; > @@ -367,6 +368,9 @@ int mmc_of_parse(struct mmc_host *host) > if (of_find_property(np, "broken-cd", &len)) > host->caps |= MMC_CAP_NEEDS_POLL; > > + if (of_property_read_u32(np, "cd-debounce-us", &debounce) < 0) > + debounce = 0; > + Hi Balaji, Sorry for a late reply. I am wondering whether this should be a generic gpio of property, instead of a mmc specific thing. I have added Linus Walleij and Alexandre Courbot, the maintainers of gpio. Let's see if they can point us in a direction. > gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags); > if (gpio == -EPROBE_DEFER) > return gpio; > @@ -374,7 +378,7 @@ int mmc_of_parse(struct mmc_host *host) > if (!(flags & OF_GPIO_ACTIVE_LOW)) > gpio_inv_cd = true; > > - ret = mmc_gpio_request_cd(host, gpio, 0); > + ret = mmc_gpio_request_cd(host, gpio, debounce); > if (ret < 0) { > dev_err(host->parent, > "Failed to request CD GPIO #%d: %d!\n", > -- > 1.7.5.4 > Kind regards Uffe -- 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
On Wed, Jun 18, 2014 at 10:47 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote: > On 9 May 2014 17:37, Balaji T K <balajitk@ti.com> wrote: >> Provide an option to get CD debounce time from DT >> >> Signed-off-by: Balaji T K <balajitk@ti.com> >> --- >> Documentation/devicetree/bindings/mmc/mmc.txt | 1 + >> drivers/mmc/core/host.c | 6 +++++- >> 2 files changed, 6 insertions(+), 1 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt >> index 9dce540..fae590b 100644 >> --- a/Documentation/devicetree/bindings/mmc/mmc.txt >> +++ b/Documentation/devicetree/bindings/mmc/mmc.txt >> @@ -17,6 +17,7 @@ Optional properties: >> - bus-width: Number of data lines, can be <1>, <4>, or <8>. The default >> will be <1> if the property is absent. >> - wp-gpios: Specify GPIOs for write protection, see gpio binding >> +- cd-debounce-us: debounce time in microseconds for card detect gpio. >> - cd-inverted: when present, polarity on the CD line is inverted. See the note >> below for the case, when a GPIO is used for the CD line >> - wp-inverted: when present, polarity on the WP line is inverted. See the note >> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c >> index fdea825..59cd3a0 100644 >> --- a/drivers/mmc/core/host.c >> +++ b/drivers/mmc/core/host.c >> @@ -313,6 +313,7 @@ int mmc_of_parse(struct mmc_host *host) >> bool explicit_inv_wp, gpio_inv_wp = false; >> enum of_gpio_flags flags; >> int len, ret, gpio; >> + unsigned int debounce; >> >> if (!host->parent || !host->parent->of_node) >> return 0; >> @@ -367,6 +368,9 @@ int mmc_of_parse(struct mmc_host *host) >> if (of_find_property(np, "broken-cd", &len)) >> host->caps |= MMC_CAP_NEEDS_POLL; >> >> + if (of_property_read_u32(np, "cd-debounce-us", &debounce) < 0) >> + debounce = 0; >> + > > Hi Balaji, > > Sorry for a late reply. > > I am wondering whether this should be a generic gpio of property, > instead of a mmc specific thing. > > I have added Linus Walleij and Alexandre Courbot, the maintainers of > gpio. Let's see if they can point us in a direction. I agree it would be nice if the debounce value could be handled by the GPIO framework. I just wonder what would be the correct way of doing it? Contrary to ACTIVE_LOW and other flags which can be specified with the GPIO phandle, debounce is a numeric value. Maybe using a different property, e.g.: cd-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>; cd-gpios-debounce = <10>; When looking up a GPIO through gpiod_get(), the GPIO framework could then check for -debounce property and set the debounce time accordingly. At first sight I'd say that would work and could be used for MMC and all other subsystems that need something similar. Alex. -- 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
On Sat, Jun 21, 2014 at 9:22 AM, Alexandre Courbot <gnurou@gmail.com> wrote: >> I have added Linus Walleij and Alexandre Courbot, the maintainers of >> gpio. Let's see if they can point us in a direction. > > I agree it would be nice if the debounce value could be handled by the > GPIO framework. I agree too. > I just wonder what would be the correct way of doing > it? Contrary to ACTIVE_LOW and other flags which can be specified with > the GPIO phandle, debounce is a numeric value. Maybe using a different > property, e.g.: > > cd-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>; > cd-gpios-debounce = <10>; > > When looking up a GPIO through gpiod_get(), the GPIO framework could > then check for -debounce property and set the debounce time > accordingly. At first sight I'd say that would work and could be used > for MMC and all other subsystems that need something similar. Yes, but we also need to write generic debounce handling into the gpiolib, so it doesn't matter if the GPIO driver can or cannot handle this itself. Some hardware has the capability to debounce lines in *hardware*. Right now a call to gpiod_set_debounce() will fail unless the hardware has a debounce option. What we should really do is make gpiod_set_debounce() always work, put the debounce value into the gpio_desc, and move some logic similar to what exists in drivers/input/keyboard/gpio_keys.c into the gpiolib, then get rid of any local implementations like in gpio_keys. Then we can rely on the gpiolib handling this at all times, and also to get the debounce config from DT. Dmitry, opinions on this? Anyone up for implementing the timer in gpiolib and moving the keyboard driver over to using the gpiolib debounce set? Yours, Linus Walleij -- 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
On Mon, Jul 7, 2014 at 8:12 AM, Linus Walleij <linus.walleij@linaro.org> wrote: > On Sat, Jun 21, 2014 at 9:22 AM, Alexandre Courbot <gnurou@gmail.com> wrote: > >>> I have added Linus Walleij and Alexandre Courbot, the maintainers of >>> gpio. Let's see if they can point us in a direction. >> >> I agree it would be nice if the debounce value could be handled by the >> GPIO framework. > > I agree too. > >> I just wonder what would be the correct way of doing >> it? Contrary to ACTIVE_LOW and other flags which can be specified with >> the GPIO phandle, debounce is a numeric value. Maybe using a different >> property, e.g.: >> >> cd-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>; >> cd-gpios-debounce = <10>; >> >> When looking up a GPIO through gpiod_get(), the GPIO framework could >> then check for -debounce property and set the debounce time >> accordingly. At first sight I'd say that would work and could be used >> for MMC and all other subsystems that need something similar. > > Yes, but we also need to write generic debounce handling into > the gpiolib, so it doesn't matter if the GPIO driver can or cannot > handle this itself. Some hardware has the capability to debounce > lines in *hardware*. > > Right now a call to gpiod_set_debounce() will fail unless the > hardware has a debounce option. > > What we should really do is make gpiod_set_debounce() always > work, put the debounce value into the gpio_desc, and move some > logic similar to what exists in drivers/input/keyboard/gpio_keys.c > into the gpiolib, then get rid of any local implementations like > in gpio_keys. > > Then we can rely on the gpiolib handling this at all times, and also > to get the debounce config from DT. > > Dmitry, opinions on this? I am always happy to hear when common functionality is moved into appropriate layer. Thanks.
On Tue, Jul 8, 2014 at 12:12 AM, Linus Walleij <linus.walleij@linaro.org> wrote: > On Sat, Jun 21, 2014 at 9:22 AM, Alexandre Courbot <gnurou@gmail.com> wrote: > >>> I have added Linus Walleij and Alexandre Courbot, the maintainers of >>> gpio. Let's see if they can point us in a direction. >> >> I agree it would be nice if the debounce value could be handled by the >> GPIO framework. > > I agree too. > >> I just wonder what would be the correct way of doing >> it? Contrary to ACTIVE_LOW and other flags which can be specified with >> the GPIO phandle, debounce is a numeric value. Maybe using a different >> property, e.g.: >> >> cd-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>; >> cd-gpios-debounce = <10>; >> >> When looking up a GPIO through gpiod_get(), the GPIO framework could >> then check for -debounce property and set the debounce time >> accordingly. At first sight I'd say that would work and could be used >> for MMC and all other subsystems that need something similar. > > Yes, but we also need to write generic debounce handling into > the gpiolib, so it doesn't matter if the GPIO driver can or cannot > handle this itself. Some hardware has the capability to debounce > lines in *hardware*. > > Right now a call to gpiod_set_debounce() will fail unless the > hardware has a debounce option. > > What we should really do is make gpiod_set_debounce() always > work, put the debounce value into the gpio_desc, and move some > logic similar to what exists in drivers/input/keyboard/gpio_keys.c > into the gpiolib, then get rid of any local implementations like > in gpio_keys. > > Then we can rely on the gpiolib handling this at all times, and also > to get the debounce config from DT. > > Dmitry, opinions on this? > > Anyone up for implementing the timer in gpiolib and moving the > keyboard driver over to using the gpiolib debounce set? If this can wait a bit for the Grand GPIO Refactoring and concurrent GPIO consumers to be done, I don't mind giving this a shot next. If someone else wants/needs it faster, please feel free to take over of course. -- 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/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt index 9dce540..fae590b 100644 --- a/Documentation/devicetree/bindings/mmc/mmc.txt +++ b/Documentation/devicetree/bindings/mmc/mmc.txt @@ -17,6 +17,7 @@ Optional properties: - bus-width: Number of data lines, can be <1>, <4>, or <8>. The default will be <1> if the property is absent. - wp-gpios: Specify GPIOs for write protection, see gpio binding +- cd-debounce-us: debounce time in microseconds for card detect gpio. - cd-inverted: when present, polarity on the CD line is inverted. See the note below for the case, when a GPIO is used for the CD line - wp-inverted: when present, polarity on the WP line is inverted. See the note diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index fdea825..59cd3a0 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -313,6 +313,7 @@ int mmc_of_parse(struct mmc_host *host) bool explicit_inv_wp, gpio_inv_wp = false; enum of_gpio_flags flags; int len, ret, gpio; + unsigned int debounce; if (!host->parent || !host->parent->of_node) return 0; @@ -367,6 +368,9 @@ int mmc_of_parse(struct mmc_host *host) if (of_find_property(np, "broken-cd", &len)) host->caps |= MMC_CAP_NEEDS_POLL; + if (of_property_read_u32(np, "cd-debounce-us", &debounce) < 0) + debounce = 0; + gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags); if (gpio == -EPROBE_DEFER) return gpio; @@ -374,7 +378,7 @@ int mmc_of_parse(struct mmc_host *host) if (!(flags & OF_GPIO_ACTIVE_LOW)) gpio_inv_cd = true; - ret = mmc_gpio_request_cd(host, gpio, 0); + ret = mmc_gpio_request_cd(host, gpio, debounce); if (ret < 0) { dev_err(host->parent, "Failed to request CD GPIO #%d: %d!\n",
Provide an option to get CD debounce time from DT Signed-off-by: Balaji T K <balajitk@ti.com> --- Documentation/devicetree/bindings/mmc/mmc.txt | 1 + drivers/mmc/core/host.c | 6 +++++- 2 files changed, 6 insertions(+), 1 deletions(-)