diff options
Diffstat (limited to 'drivers/clk/clk-gpio.c')
| -rw-r--r-- | drivers/clk/clk-gpio.c | 455 |
1 files changed, 291 insertions, 164 deletions
diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c index 86b245746a6b..9099c57e2715 100644 --- a/drivers/clk/clk-gpio.c +++ b/drivers/clk/clk-gpio.c @@ -1,38 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - http://www.ti.com + * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - https://www.ti.com * * Authors: * Jyri Sarha <jsarha@ti.com> * Sergej Sawazki <ce3a@gmx.de> * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * * Gpio controlled clock implementation */ #include <linux/clk-provider.h> #include <linux/export.h> #include <linux/slab.h> -#include <linux/gpio.h> #include <linux/gpio/consumer.h> -#include <linux/of_gpio.h> #include <linux/err.h> #include <linux/device.h> +#include <linux/of.h> #include <linux/platform_device.h> -#include <linux/of_device.h> +#include <linux/regulator/consumer.h> /** * DOC: basic gpio gated clock which can be enabled and disabled * with gpio output * Traits of this clock: - * prepare - clk_(un)prepare only ensures parent is (un)prepared - * enable - clk_enable and clk_disable are functional & control gpio + * prepare - clk_(un)prepare are functional and control a gpio that can sleep + * enable - clk_enable and clk_disable are functional & control + * non-sleeping gpio * rate - inherits rate from parent. No clk_set_rate support * parent - fixed parent. No clk_set_parent support */ +/** + * struct clk_gpio - gpio gated clock + * + * @hw: handle between common and hardware-specific interfaces + * @gpiod: gpio descriptor + * + * Clock with a gpio control for enabling and disabling the parent clock + * or switching between two parents by asserting or deasserting the gpio. + * + * Implements .enable, .disable and .is_enabled or + * .get_parent, .set_parent and .determine_rate depending on which clk_ops + * is used. + */ +struct clk_gpio { + struct clk_hw hw; + struct gpio_desc *gpiod; +}; + +#define to_clk_gpio(_hw) container_of(_hw, struct clk_gpio, hw) + static int clk_gpio_gate_enable(struct clk_hw *hw) { struct clk_gpio *clk = to_clk_gpio(hw); @@ -56,12 +73,40 @@ static int clk_gpio_gate_is_enabled(struct clk_hw *hw) return gpiod_get_value(clk->gpiod); } -const struct clk_ops clk_gpio_gate_ops = { +static const struct clk_ops clk_gpio_gate_ops = { .enable = clk_gpio_gate_enable, .disable = clk_gpio_gate_disable, .is_enabled = clk_gpio_gate_is_enabled, }; -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 @@ -75,225 +120,307 @@ static u8 clk_gpio_mux_get_parent(struct clk_hw *hw) { struct clk_gpio *clk = to_clk_gpio(hw); - return gpiod_get_value(clk->gpiod); + return gpiod_get_value_cansleep(clk->gpiod); } static int clk_gpio_mux_set_parent(struct clk_hw *hw, u8 index) { struct clk_gpio *clk = to_clk_gpio(hw); - gpiod_set_value(clk->gpiod, index); + gpiod_set_value_cansleep(clk->gpiod, index); return 0; } -const struct clk_ops clk_gpio_mux_ops = { +static const struct clk_ops clk_gpio_mux_ops = { .get_parent = clk_gpio_mux_get_parent, .set_parent = clk_gpio_mux_set_parent, .determine_rate = __clk_mux_determine_rate, }; -EXPORT_SYMBOL_GPL(clk_gpio_mux_ops); -static struct clk_hw *clk_register_gpio(struct device *dev, const char *name, - const char * const *parent_names, u8 num_parents, unsigned gpio, - bool active_low, unsigned long flags, - const struct clk_ops *clk_gpio_ops) +static struct clk_hw *clk_register_gpio(struct device *dev, u8 num_parents, + struct gpio_desc *gpiod, + const struct clk_ops *clk_gpio_ops) { struct clk_gpio *clk_gpio; struct clk_hw *hw; struct clk_init_data init = {}; - unsigned long gpio_flags; int err; + const struct clk_parent_data gpio_parent_data[] = { + { .index = 0 }, + { .index = 1 }, + }; - if (dev) - clk_gpio = devm_kzalloc(dev, sizeof(*clk_gpio), GFP_KERNEL); - else - clk_gpio = kzalloc(sizeof(*clk_gpio), GFP_KERNEL); - + clk_gpio = devm_kzalloc(dev, sizeof(*clk_gpio), GFP_KERNEL); if (!clk_gpio) return ERR_PTR(-ENOMEM); - if (active_low) - gpio_flags = GPIOF_ACTIVE_LOW | GPIOF_OUT_INIT_HIGH; - else - gpio_flags = GPIOF_OUT_INIT_LOW; - - if (dev) - err = devm_gpio_request_one(dev, gpio, gpio_flags, name); - else - err = gpio_request_one(gpio, gpio_flags, name); - if (err) { - if (err != -EPROBE_DEFER) - pr_err("%s: %s: Error requesting clock control gpio %u\n", - __func__, name, gpio); - if (!dev) - kfree(clk_gpio); - - return ERR_PTR(err); - } - - init.name = name; + init.name = dev->of_node->name; init.ops = clk_gpio_ops; - init.flags = flags | CLK_IS_BASIC; - init.parent_names = parent_names; + init.parent_data = gpio_parent_data; init.num_parents = num_parents; + init.flags = CLK_SET_RATE_PARENT; - clk_gpio->gpiod = gpio_to_desc(gpio); + clk_gpio->gpiod = gpiod; clk_gpio->hw.init = &init; hw = &clk_gpio->hw; - if (dev) - err = devm_clk_hw_register(dev, hw); - else - err = clk_hw_register(NULL, hw); + err = devm_clk_hw_register(dev, hw); + if (err) + return ERR_PTR(err); - if (!err) - return hw; + return hw; +} - if (!dev) { - gpiod_put(clk_gpio->gpiod); - kfree(clk_gpio); - } +static struct clk_hw *clk_hw_register_gpio_gate(struct device *dev, + int num_parents, + struct gpio_desc *gpiod) +{ + const struct clk_ops *ops; + + if (gpiod_cansleep(gpiod)) + ops = &clk_sleeping_gpio_gate_ops; + else + ops = &clk_gpio_gate_ops; - return ERR_PTR(err); + return clk_register_gpio(dev, num_parents, gpiod, ops); } -/** - * clk_hw_register_gpio_gate - register a gpio clock gate with the clock - * framework - * @dev: device that is registering this clock - * @name: name of this clock - * @parent_name: name of this clock's parent - * @gpio: gpio number to gate this clock - * @active_low: true if gpio should be set to 0 to enable clock - * @flags: clock flags - */ -struct clk_hw *clk_hw_register_gpio_gate(struct device *dev, const char *name, - const char *parent_name, unsigned gpio, bool active_low, - unsigned long flags) +static struct clk_hw *clk_hw_register_gpio_mux(struct device *dev, + struct gpio_desc *gpiod) { - return clk_register_gpio(dev, name, - (parent_name ? &parent_name : NULL), - (parent_name ? 1 : 0), gpio, active_low, flags, - &clk_gpio_gate_ops); + return clk_register_gpio(dev, 2, gpiod, &clk_gpio_mux_ops); } -EXPORT_SYMBOL_GPL(clk_hw_register_gpio_gate); -struct clk *clk_register_gpio_gate(struct device *dev, const char *name, - const char *parent_name, unsigned gpio, bool active_low, - unsigned long flags) +static int gpio_clk_driver_probe(struct platform_device *pdev) { + struct device *dev = &pdev->dev; + struct device_node *node = dev->of_node; + const char *gpio_name; + unsigned int num_parents; + struct gpio_desc *gpiod; struct clk_hw *hw; + bool is_mux; - hw = clk_hw_register_gpio_gate(dev, name, parent_name, gpio, active_low, - flags); + is_mux = of_device_is_compatible(node, "gpio-mux-clock"); + + num_parents = of_clk_get_parent_count(node); + if (is_mux && num_parents != 2) { + dev_err(dev, "mux-clock must have 2 parents\n"); + return -EINVAL; + } + + gpio_name = is_mux ? "select" : "enable"; + gpiod = devm_gpiod_get(dev, gpio_name, GPIOD_OUT_LOW); + if (IS_ERR(gpiod)) + return dev_err_probe(dev, PTR_ERR(gpiod), + "Can't get '%s' named GPIO property\n", gpio_name); + + if (is_mux) + hw = clk_hw_register_gpio_mux(dev, gpiod); + else + hw = clk_hw_register_gpio_gate(dev, num_parents, gpiod); if (IS_ERR(hw)) - return ERR_CAST(hw); - return hw->clk; + return PTR_ERR(hw); + + return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw); } -EXPORT_SYMBOL_GPL(clk_register_gpio_gate); + +static const struct of_device_id gpio_clk_match_table[] = { + { .compatible = "gpio-mux-clock" }, + { .compatible = "gpio-gate-clock" }, + { } +}; + +static struct platform_driver gpio_clk_driver = { + .probe = gpio_clk_driver_probe, + .driver = { + .name = "gpio-clk", + .of_match_table = gpio_clk_match_table, + }, +}; +builtin_platform_driver(gpio_clk_driver); /** - * clk_hw_register_gpio_mux - register a gpio clock mux with the clock framework - * @dev: device that is registering this clock - * @name: name of this clock - * @parent_names: names of this clock's parents - * @num_parents: number of parents listed in @parent_names - * @gpio: gpio number to gate this clock - * @active_low: true if gpio should be set to 0 to enable clock - * @flags: clock flags + * DOC: gated fixed clock, controlled with a gpio output and a regulator + * Traits of this clock: + * prepare - clk_prepare and clk_unprepare are function & control regulator + * optionally a gpio that can sleep + * enable - clk_enable and clk_disable are functional & control gpio + * rate - rate is fixed and set on clock registration + * parent - fixed clock is a root clock and has no parent */ -struct clk_hw *clk_hw_register_gpio_mux(struct device *dev, const char *name, - const char * const *parent_names, u8 num_parents, unsigned gpio, - bool active_low, unsigned long flags) + +/** + * struct clk_gated_fixed - Gateable fixed rate clock + * @clk_gpio: instance of clk_gpio for gate-gpio + * @supply: supply regulator + * @rate: fixed rate + */ +struct clk_gated_fixed { + struct clk_gpio clk_gpio; + struct regulator *supply; + unsigned long rate; +}; + +#define to_clk_gated_fixed(_clk_gpio) container_of(_clk_gpio, struct clk_gated_fixed, clk_gpio) + +static unsigned long clk_gated_fixed_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) { - if (num_parents != 2) { - pr_err("mux-clock %s must have 2 parents\n", name); - return ERR_PTR(-EINVAL); - } + return to_clk_gated_fixed(to_clk_gpio(hw))->rate; +} - return clk_register_gpio(dev, name, parent_names, num_parents, - gpio, active_low, flags, &clk_gpio_mux_ops); +static int clk_gated_fixed_prepare(struct clk_hw *hw) +{ + struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw)); + + if (!clk->supply) + return 0; + + return regulator_enable(clk->supply); } -EXPORT_SYMBOL_GPL(clk_hw_register_gpio_mux); -struct clk *clk_register_gpio_mux(struct device *dev, const char *name, - const char * const *parent_names, u8 num_parents, unsigned gpio, - bool active_low, unsigned long flags) +static void clk_gated_fixed_unprepare(struct clk_hw *hw) { - struct clk_hw *hw; + struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw)); - hw = clk_hw_register_gpio_mux(dev, name, parent_names, num_parents, - gpio, active_low, flags); - if (IS_ERR(hw)) - return ERR_CAST(hw); - return hw->clk; + if (!clk->supply) + return; + + regulator_disable(clk->supply); } -EXPORT_SYMBOL_GPL(clk_register_gpio_mux); -static int gpio_clk_driver_probe(struct platform_device *pdev) +static int clk_gated_fixed_is_prepared(struct clk_hw *hw) { - struct device_node *node = pdev->dev.of_node; - const char **parent_names, *gpio_name; - unsigned int num_parents; - int gpio; - enum of_gpio_flags of_flags; - struct clk *clk; - bool active_low, is_mux; + struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw)); - num_parents = of_clk_get_parent_count(node); - if (num_parents) { - parent_names = devm_kcalloc(&pdev->dev, num_parents, - sizeof(char *), GFP_KERNEL); - if (!parent_names) - return -ENOMEM; - - of_clk_parent_fill(node, parent_names, num_parents); - } else { - parent_names = NULL; - } + if (!clk->supply) + return true; - is_mux = of_device_is_compatible(node, "gpio-mux-clock"); + return regulator_is_enabled(clk->supply); +} + +/* + * Fixed gated clock with non-sleeping gpio. + * + * Prepare operation turns on the supply regulator + * and the enable operation switches the enable-gpio. + */ +static const struct clk_ops clk_gated_fixed_ops = { + .prepare = clk_gated_fixed_prepare, + .unprepare = clk_gated_fixed_unprepare, + .is_prepared = clk_gated_fixed_is_prepared, + .enable = clk_gpio_gate_enable, + .disable = clk_gpio_gate_disable, + .is_enabled = clk_gpio_gate_is_enabled, + .recalc_rate = clk_gated_fixed_recalc_rate, +}; - gpio_name = is_mux ? "select-gpios" : "enable-gpios"; - gpio = of_get_named_gpio_flags(node, gpio_name, 0, &of_flags); - if (gpio < 0) { - if (gpio == -EPROBE_DEFER) - pr_debug("%s: %s: GPIOs not yet available, retry later\n", - node->name, __func__); - else - pr_err("%s: %s: Can't get '%s' DT property\n", - node->name, __func__, - gpio_name); - return gpio; +static int clk_sleeping_gated_fixed_prepare(struct clk_hw *hw) +{ + int ret; + + ret = clk_gated_fixed_prepare(hw); + if (ret) + return ret; + + ret = clk_sleeping_gpio_gate_prepare(hw); + if (ret) + clk_gated_fixed_unprepare(hw); + + return ret; +} + +static void clk_sleeping_gated_fixed_unprepare(struct clk_hw *hw) +{ + clk_gated_fixed_unprepare(hw); + clk_sleeping_gpio_gate_unprepare(hw); +} + +/* + * Fixed gated clock with non-sleeping gpio. + * + * Enabling the supply regulator and switching the enable-gpio happens + * both in the prepare step. + * is_prepared only needs to check the gpio state, as toggling the + * gpio is the last step when preparing. + */ +static const struct clk_ops clk_sleeping_gated_fixed_ops = { + .prepare = clk_sleeping_gated_fixed_prepare, + .unprepare = clk_sleeping_gated_fixed_unprepare, + .is_prepared = clk_sleeping_gpio_gate_is_prepared, + .recalc_rate = clk_gated_fixed_recalc_rate, +}; + +static int clk_gated_fixed_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct clk_gated_fixed *clk; + const struct clk_ops *ops; + const char *clk_name; + u32 rate; + int ret; + + clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL); + if (!clk) + return -ENOMEM; + + ret = device_property_read_u32(dev, "clock-frequency", &rate); + if (ret) + return dev_err_probe(dev, ret, "Failed to get clock-frequency\n"); + clk->rate = rate; + + ret = device_property_read_string(dev, "clock-output-names", &clk_name); + if (ret) + clk_name = fwnode_get_name(dev->fwnode); + + clk->supply = devm_regulator_get_optional(dev, "vdd"); + if (IS_ERR(clk->supply)) { + if (PTR_ERR(clk->supply) != -ENODEV) + return dev_err_probe(dev, PTR_ERR(clk->supply), + "Failed to get regulator\n"); + clk->supply = NULL; } - active_low = of_flags & OF_GPIO_ACTIVE_LOW; + clk->clk_gpio.gpiod = devm_gpiod_get_optional(dev, "enable", + GPIOD_OUT_LOW); + if (IS_ERR(clk->clk_gpio.gpiod)) + return dev_err_probe(dev, PTR_ERR(clk->clk_gpio.gpiod), + "Failed to get gpio\n"); - if (is_mux) - clk = clk_register_gpio_mux(&pdev->dev, node->name, - parent_names, num_parents, gpio, active_low, 0); + if (gpiod_cansleep(clk->clk_gpio.gpiod)) + ops = &clk_sleeping_gated_fixed_ops; else - clk = clk_register_gpio_gate(&pdev->dev, node->name, - parent_names ? parent_names[0] : NULL, gpio, - active_low, 0); - if (IS_ERR(clk)) - return PTR_ERR(clk); + ops = &clk_gated_fixed_ops; + + clk->clk_gpio.hw.init = CLK_HW_INIT_NO_PARENT(clk_name, ops, 0); - return of_clk_add_provider(node, of_clk_src_simple_get, clk); + /* register the clock */ + ret = devm_clk_hw_register(dev, &clk->clk_gpio.hw); + if (ret) + return dev_err_probe(dev, ret, + "Failed to register clock\n"); + + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, + &clk->clk_gpio.hw); + if (ret) + return dev_err_probe(dev, ret, + "Failed to register clock provider\n"); + + return 0; } -static const struct of_device_id gpio_clk_match_table[] = { - { .compatible = "gpio-mux-clock" }, - { .compatible = "gpio-gate-clock" }, - { } +static const struct of_device_id gated_fixed_clk_match_table[] = { + { .compatible = "gated-fixed-clock" }, + { /* sentinel */ } }; -static struct platform_driver gpio_clk_driver = { - .probe = gpio_clk_driver_probe, +static struct platform_driver gated_fixed_clk_driver = { + .probe = clk_gated_fixed_probe, .driver = { - .name = "gpio-clk", - .of_match_table = gpio_clk_match_table, + .name = "gated-fixed-clk", + .of_match_table = gated_fixed_clk_match_table, }, }; -builtin_platform_driver(gpio_clk_driver); +builtin_platform_driver(gated_fixed_clk_driver); |