Messages in this thread | | | Subject | Re: [PATCH] clk: clk-gpio: add support for sleeping GPIOs in gpio-gate-clk | From | Stephen Boyd <> | Date | Wed, 13 Feb 2019 09:14:22 -0800 |
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Quoting Thomas Petazzoni (2019-02-11 05:58:18) > The current implementation of gpio-gate-clk enables/disables the clock > using the GPIO in the ->enable() and ->disable() clock callbacks. This > requires the GPIO to be configurable in atomic contexts. While it is > the case for most memory-mapped GPIO controllers, it is not the case > for GPIO expanders on I2C or SPI. > > This commit extends the gpio-gate-clk to check whether the GPIO calls > require sleeping or not. If sleeping is not required, the current > implementation based on ->enable()/->disable() is kept. However, if > sleeping is needed, we instead implement the logic in the ->prepare() > and ->unprepare() hooks. Thanks to this, a gate clock connected to a > GPIO on a GPIO expander can be controlled with the existing driver. > > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Sounds like a good idea!
> diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c > index 6a43ce420492..f5d481713c7d 100644 > --- a/drivers/clk/clk-gpio.c > +++ b/drivers/clk/clk-gpio.c > @@ -61,6 +61,35 @@ const struct clk_ops clk_gpio_gate_ops = { > }; > EXPORT_SYMBOL_GPL(clk_gpio_gate_ops); > > +static int clk_sleeping_gpio_gate_prepare(struct clk_hw *hw) > +{ > + struct clk_gpio *clk = to_clk_gpio(hw); > + > + gpiod_set_value_cansleep(clk->gpiod, 1); > + > + return 0; > +} > + > +static void clk_sleeping_gpio_gate_unprepare(struct clk_hw *hw) > +{ > + struct clk_gpio *clk = to_clk_gpio(hw); > + > + gpiod_set_value_cansleep(clk->gpiod, 0); > +} > + > +static int clk_sleeping_gpio_gate_is_prepared(struct clk_hw *hw) > +{ > + struct clk_gpio *clk = to_clk_gpio(hw); > + > + return gpiod_get_value_cansleep(clk->gpiod); > +} > + > +const struct clk_ops clk_sleeping_gpio_gate_ops = {
static?
> + .prepare = clk_sleeping_gpio_gate_prepare, > + .unprepare = clk_sleeping_gpio_gate_unprepare, > + .is_prepared = clk_sleeping_gpio_gate_is_prepared, > +}; > + > /** > * DOC: basic clock multiplexer which can be controlled with a gpio output > * Traits of this clock:
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