clk: clk-gpio: add support for sleeping GPIOs in gpio-gate-clk (c0189fee) · Commits · 戴 / test

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> [sboyd@kernel.org: Mark clk ops static] Signed-off-by:

Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk-gpio.c

+37 −2

Original line number	Diff line number	Diff line
		@@ -58,6 +58,35 @@ 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);
		}

		static const struct clk_ops clk_sleeping_gpio_gate_ops = {
		.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:
		@@ -144,10 +173,16 @@ struct clk_hw clk_hw_register_gpio_gate(struct device dev, const char *name,
		const char parent_name, struct gpio_desc gpiod,
		unsigned long flags)
		{
		const struct clk_ops *ops;

		if (gpiod_cansleep(gpiod))
		ops = &clk_sleeping_gpio_gate_ops;
		else
		ops = &clk_gpio_gate_ops;

		return clk_register_gpio(dev, name,
		(parent_name ? &parent_name : NULL),
		(parent_name ? 1 : 0), gpiod, flags,
		&clk_gpio_gate_ops);
		(parent_name ? 1 : 0), gpiod, flags, ops);
		}
		EXPORT_SYMBOL_GPL(clk_hw_register_gpio_gate);

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