1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - https://www.ti.com
9  * Gpio controlled clock implementation
12 #include <linux/clk-provider.h>
23  * DOC: basic gpio gated clock which can be enabled and disabled
25  * Traits of this clock:
26  * prepare - clk_(un)prepare are functional and control a gpio that can sleep
27  * enable - clk_enable and clk_disable are functional & control
28  *          non-sleeping gpio
29  * rate - inherits rate from parent.  No clk_set_rate support
30  * parent - fixed parent.  No clk_set_parent support
34  * struct clk_gpio - gpio gated clock
36  * @hw:		handle between common and hardware-specific interfaces
39  * Clock with a gpio control for enabling and disabling the parent clock
57 	gpiod_set_value(clk->gpiod, 1);  in clk_gpio_gate_enable()
66 	gpiod_set_value(clk->gpiod, 0);  in clk_gpio_gate_disable()
73 	return gpiod_get_value(clk->gpiod);  in clk_gpio_gate_is_enabled()
86 	gpiod_set_value_cansleep(clk->gpiod, 1);  in clk_sleeping_gpio_gate_prepare()
95 	gpiod_set_value_cansleep(clk->gpiod, 0);  in clk_sleeping_gpio_gate_unprepare()
102 	return gpiod_get_value_cansleep(clk->gpiod);  in clk_sleeping_gpio_gate_is_prepared()
112  * DOC: basic clock multiplexer which can be controlled with a gpio output
113  * Traits of this clock:
114  * prepare - clk_prepare only ensures that parents are prepared
115  * rate - rate is only affected by parent switching.  No clk_set_rate support
116  * parent - parent is adjustable through clk_set_parent
123 	return gpiod_get_value_cansleep(clk->gpiod);  in clk_gpio_mux_get_parent()
130 	gpiod_set_value_cansleep(clk->gpiod, index);  in clk_gpio_mux_set_parent()
156 		return ERR_PTR(-ENOMEM);  in clk_register_gpio()
158 	init.name = dev->of_node->name;  in clk_register_gpio()
164 	clk_gpio->gpiod = gpiod;  in clk_register_gpio()
165 	clk_gpio->hw.init = &init;  in clk_register_gpio()
167 	hw = &clk_gpio->hw;  in clk_register_gpio()
197 	struct device *dev = &pdev->dev;  in gpio_clk_driver_probe()
198 	struct device_node *node = dev->of_node;  in gpio_clk_driver_probe()
205 	is_mux = of_device_is_compatible(node, "gpio-mux-clock");  in gpio_clk_driver_probe()
209 		dev_err(dev, "mux-clock must have 2 parents\n");  in gpio_clk_driver_probe()
210 		return -EINVAL;  in gpio_clk_driver_probe()
230 	{ .compatible = "gpio-mux-clock" },
231 	{ .compatible = "gpio-gate-clock" },
238 		.name	= "gpio-clk",
245  * DOC: gated fixed clock, controlled with a gpio output and a regulator
246  * Traits of this clock:
247  * prepare - clk_prepare and clk_unprepare are function & control regulator
249  * enable - clk_enable and clk_disable are functional & control gpio
250  * rate - rate is fixed and set on clock registration
251  * parent - fixed clock is a root clock and has no parent
255  * struct clk_gated_fixed - Gateable fixed rate clock
256  * @clk_gpio:	instance of clk_gpio for gate-gpio
258  * @rate:	fixed rate
271 	return to_clk_gated_fixed(to_clk_gpio(hw))->rate;  in clk_gated_fixed_recalc_rate()
278 	if (!clk->supply)  in clk_gated_fixed_prepare()
281 	return regulator_enable(clk->supply);  in clk_gated_fixed_prepare()
288 	if (!clk->supply)  in clk_gated_fixed_unprepare()
291 	regulator_disable(clk->supply);  in clk_gated_fixed_unprepare()
298 	if (!clk->supply)  in clk_gated_fixed_is_prepared()
301 	return regulator_is_enabled(clk->supply);  in clk_gated_fixed_is_prepared()
305  * Fixed gated clock with non-sleeping gpio.
308  * and the enable operation switches the enable-gpio.
342  * Fixed gated clock with non-sleeping gpio.
344  * Enabling the supply regulator and switching the enable-gpio happens
358 	struct device *dev = &pdev->dev;  in clk_gated_fixed_probe()
367 		return -ENOMEM;  in clk_gated_fixed_probe()
369 	ret = device_property_read_u32(dev, "clock-frequency", &rate);  in clk_gated_fixed_probe()
371 		return dev_err_probe(dev, ret, "Failed to get clock-frequency\n");  in clk_gated_fixed_probe()
372 	clk->rate = rate;  in clk_gated_fixed_probe()
374 	ret = device_property_read_string(dev, "clock-output-names", &clk_name);  in clk_gated_fixed_probe()
376 		clk_name = fwnode_get_name(dev->fwnode);  in clk_gated_fixed_probe()
378 	clk->supply = devm_regulator_get_optional(dev, "vdd");  in clk_gated_fixed_probe()
379 	if (IS_ERR(clk->supply)) {  in clk_gated_fixed_probe()
380 		if (PTR_ERR(clk->supply) != -ENODEV)  in clk_gated_fixed_probe()
381 			return dev_err_probe(dev, PTR_ERR(clk->supply),  in clk_gated_fixed_probe()
383 		clk->supply = NULL;  in clk_gated_fixed_probe()
386 	clk->clk_gpio.gpiod = devm_gpiod_get_optional(dev, "enable",  in clk_gated_fixed_probe()
388 	if (IS_ERR(clk->clk_gpio.gpiod))  in clk_gated_fixed_probe()
389 		return dev_err_probe(dev, PTR_ERR(clk->clk_gpio.gpiod),  in clk_gated_fixed_probe()
392 	if (gpiod_cansleep(clk->clk_gpio.gpiod))  in clk_gated_fixed_probe()
397 	clk->clk_gpio.hw.init = CLK_HW_INIT_NO_PARENT(clk_name, ops, 0);  in clk_gated_fixed_probe()
399 	/* register the clock */  in clk_gated_fixed_probe()
400 	ret = devm_clk_hw_register(dev, &clk->clk_gpio.hw);  in clk_gated_fixed_probe()
403 				     "Failed to register clock\n");  in clk_gated_fixed_probe()
406 					  &clk->clk_gpio.hw);  in clk_gated_fixed_probe()
409 				     "Failed to register clock provider\n");  in clk_gated_fixed_probe()
415 	{ .compatible = "gated-fixed-clock" },
422 		.name	= "gated-fixed-clk",