From bb68a4f1e5ef7f2cebe84c57e465afa68a6ab911 Mon Sep 17 00:00:00 2001 From: Sergej Sawazki Date: Sun, 28 Jun 2015 16:24:56 +0200 Subject: clk: Rename clk-gpio-gate.c to clk-gpio.c The file clk-gpio-gate.c does not only contain the gate clock, but also the mux clock. Rename the file to clk-gpio.c. Cc: Jyri Sarha Signed-off-by: Sergej Sawazki Signed-off-by: Stephen Boyd --- drivers/clk/clk-gpio.c | 322 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 322 insertions(+) create mode 100644 drivers/clk/clk-gpio.c (limited to 'drivers/clk/clk-gpio.c') diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c new file mode 100644 index 000000000000..c0d202c24a97 --- /dev/null +++ b/drivers/clk/clk-gpio.c @@ -0,0 +1,322 @@ +/* + * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - http://www.ti.com + * + * Authors: + * Jyri Sarha + * Sergej Sawazki + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +/** + * 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 + * rate - inherits rate from parent. No clk_set_rate support + * parent - fixed parent. No clk_set_parent support + */ + +#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); + + gpiod_set_value(clk->gpiod, 1); + + return 0; +} + +static void clk_gpio_gate_disable(struct clk_hw *hw) +{ + struct clk_gpio *clk = to_clk_gpio(hw); + + gpiod_set_value(clk->gpiod, 0); +} + +static int clk_gpio_gate_is_enabled(struct clk_hw *hw) +{ + struct clk_gpio *clk = to_clk_gpio(hw); + + return gpiod_get_value(clk->gpiod); +} + +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); + +/** + * DOC: basic clock multiplexer which can be controlled with a gpio output + * Traits of this clock: + * prepare - clk_prepare only ensures that parents are prepared + * rate - rate is only affected by parent switching. No clk_set_rate support + * parent - parent is adjustable through clk_set_parent + */ + +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); +} + +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); + + return 0; +} + +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 *clk_register_gpio(struct device *dev, const char *name, + const char **parent_names, u8 num_parents, unsigned gpio, + bool active_low, unsigned long flags, + const struct clk_ops *clk_gpio_ops) +{ + struct clk_gpio *clk_gpio; + struct clk *clk; + struct clk_init_data init = {}; + unsigned long gpio_flags; + int err; + + if (dev) + clk_gpio = devm_kzalloc(dev, sizeof(*clk_gpio), GFP_KERNEL); + else + clk_gpio = kzalloc(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.ops = clk_gpio_ops; + init.flags = flags | CLK_IS_BASIC; + init.parent_names = parent_names; + init.num_parents = num_parents; + + clk_gpio->gpiod = gpio_to_desc(gpio); + clk_gpio->hw.init = &init; + + if (dev) + clk = devm_clk_register(dev, &clk_gpio->hw); + else + clk = clk_register(NULL, &clk_gpio->hw); + + if (!IS_ERR(clk)) + return clk; + + if (!dev) { + gpiod_put(clk_gpio->gpiod); + kfree(clk_gpio); + } + + return clk; +} + +/** + * clk_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 *clk_register_gpio_gate(struct device *dev, const char *name, + const char *parent_name, unsigned gpio, bool active_low, + unsigned long flags) +{ + return clk_register_gpio(dev, name, + (parent_name ? &parent_name : NULL), + (parent_name ? 1 : 0), gpio, active_low, flags, + &clk_gpio_gate_ops); +} +EXPORT_SYMBOL_GPL(clk_register_gpio_gate); + +/** + * clk_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 + */ +struct clk *clk_register_gpio_mux(struct device *dev, const char *name, + const char **parent_names, u8 num_parents, unsigned gpio, + bool active_low, unsigned long flags) +{ + if (num_parents != 2) { + pr_err("mux-clock %s must have 2 parents\n", name); + return ERR_PTR(-EINVAL); + } + + return clk_register_gpio(dev, name, parent_names, num_parents, + gpio, active_low, flags, &clk_gpio_mux_ops); +} +EXPORT_SYMBOL_GPL(clk_register_gpio_mux); + +#ifdef CONFIG_OF +/** + * clk_register_get() has to be delayed, because -EPROBE_DEFER + * can not be handled properly at of_clk_init() call time. + */ + +struct clk_gpio_delayed_register_data { + const char *gpio_name; + struct device_node *node; + struct mutex lock; + struct clk *clk; + struct clk *(*clk_register_get)(const char *name, + const char **parent_names, u8 num_parents, + unsigned gpio, bool active_low); +}; + +static struct clk *of_clk_gpio_delayed_register_get( + struct of_phandle_args *clkspec, void *_data) +{ + struct clk_gpio_delayed_register_data *data = _data; + struct clk *clk; + const char **parent_names; + int i, num_parents; + int gpio; + enum of_gpio_flags of_flags; + + mutex_lock(&data->lock); + + if (data->clk) { + mutex_unlock(&data->lock); + return data->clk; + } + + gpio = of_get_named_gpio_flags(data->node, data->gpio_name, 0, + &of_flags); + if (gpio < 0) { + mutex_unlock(&data->lock); + if (gpio == -EPROBE_DEFER) + pr_debug("%s: %s: GPIOs not yet available, retry later\n", + data->node->name, __func__); + else + pr_err("%s: %s: Can't get '%s' DT property\n", + data->node->name, __func__, + data->gpio_name); + return ERR_PTR(gpio); + } + + num_parents = of_clk_get_parent_count(data->node); + + parent_names = kcalloc(num_parents, sizeof(char *), GFP_KERNEL); + if (!parent_names) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < num_parents; i++) + parent_names[i] = of_clk_get_parent_name(data->node, i); + + clk = data->clk_register_get(data->node->name, parent_names, + num_parents, gpio, of_flags & OF_GPIO_ACTIVE_LOW); + if (IS_ERR(clk)) + goto out; + + data->clk = clk; +out: + mutex_unlock(&data->lock); + kfree(parent_names); + + return clk; +} + +static struct clk *of_clk_gpio_gate_delayed_register_get(const char *name, + const char **parent_names, u8 num_parents, + unsigned gpio, bool active_low) +{ + return clk_register_gpio_gate(NULL, name, parent_names[0], + gpio, active_low, 0); +} + +static struct clk *of_clk_gpio_mux_delayed_register_get(const char *name, + const char **parent_names, u8 num_parents, unsigned gpio, + bool active_low) +{ + return clk_register_gpio_mux(NULL, name, parent_names, num_parents, + gpio, active_low, 0); +} + +static void __init of_gpio_clk_setup(struct device_node *node, + const char *gpio_name, + struct clk *(*clk_register_get)(const char *name, + const char **parent_names, u8 num_parents, + unsigned gpio, bool active_low)) +{ + struct clk_gpio_delayed_register_data *data; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return; + + data->node = node; + data->gpio_name = gpio_name; + data->clk_register_get = clk_register_get; + mutex_init(&data->lock); + + of_clk_add_provider(node, of_clk_gpio_delayed_register_get, data); +} + +static void __init of_gpio_gate_clk_setup(struct device_node *node) +{ + of_gpio_clk_setup(node, "enable-gpios", + of_clk_gpio_gate_delayed_register_get); +} +CLK_OF_DECLARE(gpio_gate_clk, "gpio-gate-clock", of_gpio_gate_clk_setup); + +void __init of_gpio_mux_clk_setup(struct device_node *node) +{ + of_gpio_clk_setup(node, "select-gpios", + of_clk_gpio_mux_delayed_register_get); +} +CLK_OF_DECLARE(gpio_mux_clk, "gpio-mux-clock", of_gpio_mux_clk_setup); +#endif -- cgit v1.2.3-55-g7522