| Message ID | 20170306141716.19120-4-romain.perier@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 6 March 2017 at 15:17, Romain Perier <romain.perier@collabora.com> wrote: > Some devices need a while between the enablement of its clk and the time > where the reset line is asserted. When this time happens between the > pre_power_on and the post_power_on callbacks, there is a need to do an > msleep at the end of the pre_power_on callback. > > This commit adds an optional DT property for such devices. > > Signed-off-by: Romain Perier <romain.perier@collabora.com> > --- > Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt | 2 ++ Split DT documentation for code changes. And make sure DT maintainers are in the loop discussing new DT bindings. > drivers/mmc/core/pwrseq_simple.c | 6 ++++++ > 2 files changed, 8 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt > index e254368..821feaaf 100644 > --- a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt > +++ b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt > @@ -18,6 +18,8 @@ Optional properties: > "ext_clock" (External clock provided to the card). > - post-power-on-delay-ms : Delay in ms after powering the card and > de-asserting the reset-gpios (if any) > +- pre-power-on-delay-ms : Delay in ms before powering the card and > + asserting the reset-gpios (if any) We have been thinking of adding this before. It seems reasonable to me, however in the earlier case we ended up adding a new mmc pwrseq variant. Let's see where we ends up here... > > Example: > > diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c > index e27019f..d8d7166 100644 > --- a/drivers/mmc/core/pwrseq_simple.c > +++ b/drivers/mmc/core/pwrseq_simple.c > @@ -27,6 +27,7 @@ struct mmc_pwrseq_simple { > struct mmc_pwrseq pwrseq; > bool clk_enabled; > u32 post_power_on_delay_ms; > + u32 pre_power_on_delay_ms; > struct clk *ext_clk; > struct gpio_descs *reset_gpios; > }; > @@ -60,6 +61,9 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host) > } > > mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); > + > + if (pwrseq->pre_power_on_delay_ms) > + msleep(pwrseq->pre_power_on_delay_ms); > } > > static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host) > @@ -130,6 +134,8 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev) > > device_property_read_u32(dev, "post-power-on-delay-ms", > &pwrseq->post_power_on_delay_ms); > + device_property_read_u32(dev, "pre-power-on-delay-ms", > + &pwrseq->pre_power_on_delay_ms); > > pwrseq->pwrseq.dev = dev; > if (device_property_read_bool(dev, "post-ios-power-on")) > -- > 2.9.3 > Kind regards Uffe
diff --git a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt index e254368..821feaaf 100644 --- a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt +++ b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt @@ -18,6 +18,8 @@ Optional properties: "ext_clock" (External clock provided to the card). - post-power-on-delay-ms : Delay in ms after powering the card and de-asserting the reset-gpios (if any) +- pre-power-on-delay-ms : Delay in ms before powering the card and + asserting the reset-gpios (if any) Example: diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c index e27019f..d8d7166 100644 --- a/drivers/mmc/core/pwrseq_simple.c +++ b/drivers/mmc/core/pwrseq_simple.c @@ -27,6 +27,7 @@ struct mmc_pwrseq_simple { struct mmc_pwrseq pwrseq; bool clk_enabled; u32 post_power_on_delay_ms; + u32 pre_power_on_delay_ms; struct clk *ext_clk; struct gpio_descs *reset_gpios; }; @@ -60,6 +61,9 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host) } mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); + + if (pwrseq->pre_power_on_delay_ms) + msleep(pwrseq->pre_power_on_delay_ms); } static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host) @@ -130,6 +134,8 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev) device_property_read_u32(dev, "post-power-on-delay-ms", &pwrseq->post_power_on_delay_ms); + device_property_read_u32(dev, "pre-power-on-delay-ms", + &pwrseq->pre_power_on_delay_ms); pwrseq->pwrseq.dev = dev; if (device_property_read_bool(dev, "post-ios-power-on"))
Some devices need a while between the enablement of its clk and the time where the reset line is asserted. When this time happens between the pre_power_on and the post_power_on callbacks, there is a need to do an msleep at the end of the pre_power_on callback. This commit adds an optional DT property for such devices. Signed-off-by: Romain Perier <romain.perier@collabora.com> --- Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt | 2 ++ drivers/mmc/core/pwrseq_simple.c | 6 ++++++ 2 files changed, 8 insertions(+)