]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - drivers/clk/clk-gpio.c
Merge branch 'fix/rt5645' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
[mirror_ubuntu-artful-kernel.git] / drivers / clk / clk-gpio.c
CommitLineData
c873d14d
JS
1/*
2 * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - http://www.ti.com
80eeb1f0
SS
3 *
4 * Authors:
5 * Jyri Sarha <jsarha@ti.com>
6 * Sergej Sawazki <ce3a@gmx.de>
c873d14d
JS
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
80eeb1f0 12 * Gpio controlled clock implementation
c873d14d
JS
13 */
14
15#include <linux/clk-provider.h>
e21b08e2 16#include <linux/export.h>
c873d14d
JS
17#include <linux/slab.h>
18#include <linux/gpio.h>
44b4aa97 19#include <linux/gpio/consumer.h>
c873d14d
JS
20#include <linux/of_gpio.h>
21#include <linux/err.h>
22#include <linux/device.h>
23
24/**
25 * DOC: basic gpio gated clock which can be enabled and disabled
26 * with gpio output
27 * Traits of this clock:
28 * prepare - clk_(un)prepare only ensures parent is (un)prepared
29 * enable - clk_enable and clk_disable are functional & control gpio
30 * rate - inherits rate from parent. No clk_set_rate support
31 * parent - fixed parent. No clk_set_parent support
32 */
33
34#define to_clk_gpio(_hw) container_of(_hw, struct clk_gpio, hw)
35
36static int clk_gpio_gate_enable(struct clk_hw *hw)
37{
38 struct clk_gpio *clk = to_clk_gpio(hw);
39
40 gpiod_set_value(clk->gpiod, 1);
41
42 return 0;
43}
44
45static void clk_gpio_gate_disable(struct clk_hw *hw)
46{
47 struct clk_gpio *clk = to_clk_gpio(hw);
48
49 gpiod_set_value(clk->gpiod, 0);
50}
51
52static int clk_gpio_gate_is_enabled(struct clk_hw *hw)
53{
54 struct clk_gpio *clk = to_clk_gpio(hw);
55
56 return gpiod_get_value(clk->gpiod);
57}
58
59const struct clk_ops clk_gpio_gate_ops = {
60 .enable = clk_gpio_gate_enable,
61 .disable = clk_gpio_gate_disable,
62 .is_enabled = clk_gpio_gate_is_enabled,
63};
64EXPORT_SYMBOL_GPL(clk_gpio_gate_ops);
65
66/**
80eeb1f0
SS
67 * DOC: basic clock multiplexer which can be controlled with a gpio output
68 * Traits of this clock:
69 * prepare - clk_prepare only ensures that parents are prepared
70 * rate - rate is only affected by parent switching. No clk_set_rate support
71 * parent - parent is adjustable through clk_set_parent
c873d14d 72 */
80eeb1f0
SS
73
74static u8 clk_gpio_mux_get_parent(struct clk_hw *hw)
c873d14d 75{
80eeb1f0
SS
76 struct clk_gpio *clk = to_clk_gpio(hw);
77
78 return gpiod_get_value(clk->gpiod);
79}
80
81static int clk_gpio_mux_set_parent(struct clk_hw *hw, u8 index)
82{
83 struct clk_gpio *clk = to_clk_gpio(hw);
84
85 gpiod_set_value(clk->gpiod, index);
86
87 return 0;
88}
89
90const struct clk_ops clk_gpio_mux_ops = {
91 .get_parent = clk_gpio_mux_get_parent,
92 .set_parent = clk_gpio_mux_set_parent,
93 .determine_rate = __clk_mux_determine_rate,
94};
95EXPORT_SYMBOL_GPL(clk_gpio_mux_ops);
96
97static struct clk *clk_register_gpio(struct device *dev, const char *name,
37bff2c1 98 const char * const *parent_names, u8 num_parents, unsigned gpio,
80eeb1f0
SS
99 bool active_low, unsigned long flags,
100 const struct clk_ops *clk_gpio_ops)
101{
102 struct clk_gpio *clk_gpio;
103 struct clk *clk;
104 struct clk_init_data init = {};
c873d14d
JS
105 unsigned long gpio_flags;
106 int err;
107
80eeb1f0
SS
108 if (dev)
109 clk_gpio = devm_kzalloc(dev, sizeof(*clk_gpio), GFP_KERNEL);
110 else
111 clk_gpio = kzalloc(sizeof(*clk_gpio), GFP_KERNEL);
112
113 if (!clk_gpio)
114 return ERR_PTR(-ENOMEM);
115
820ad975
MF
116 if (active_low)
117 gpio_flags = GPIOF_ACTIVE_LOW | GPIOF_OUT_INIT_HIGH;
c873d14d
JS
118 else
119 gpio_flags = GPIOF_OUT_INIT_LOW;
120
121 if (dev)
820ad975 122 err = devm_gpio_request_one(dev, gpio, gpio_flags, name);
c873d14d 123 else
820ad975 124 err = gpio_request_one(gpio, gpio_flags, name);
c873d14d 125 if (err) {
281cbb00
SS
126 if (err != -EPROBE_DEFER)
127 pr_err("%s: %s: Error requesting clock control gpio %u\n",
128 __func__, name, gpio);
80eeb1f0
SS
129 if (!dev)
130 kfree(clk_gpio);
c873d14d 131
80eeb1f0 132 return ERR_PTR(err);
c873d14d
JS
133 }
134
135 init.name = name;
80eeb1f0 136 init.ops = clk_gpio_ops;
c873d14d 137 init.flags = flags | CLK_IS_BASIC;
80eeb1f0
SS
138 init.parent_names = parent_names;
139 init.num_parents = num_parents;
c873d14d 140
820ad975 141 clk_gpio->gpiod = gpio_to_desc(gpio);
c873d14d
JS
142 clk_gpio->hw.init = &init;
143
80eeb1f0
SS
144 if (dev)
145 clk = devm_clk_register(dev, &clk_gpio->hw);
146 else
147 clk = clk_register(NULL, &clk_gpio->hw);
c873d14d
JS
148
149 if (!IS_ERR(clk))
150 return clk;
151
80eeb1f0
SS
152 if (!dev) {
153 gpiod_put(clk_gpio->gpiod);
c873d14d 154 kfree(clk_gpio);
80eeb1f0 155 }
c873d14d
JS
156
157 return clk;
158}
80eeb1f0
SS
159
160/**
161 * clk_register_gpio_gate - register a gpio clock gate with the clock framework
162 * @dev: device that is registering this clock
163 * @name: name of this clock
164 * @parent_name: name of this clock's parent
165 * @gpio: gpio number to gate this clock
166 * @active_low: true if gpio should be set to 0 to enable clock
167 * @flags: clock flags
168 */
169struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
170 const char *parent_name, unsigned gpio, bool active_low,
171 unsigned long flags)
172{
173 return clk_register_gpio(dev, name,
174 (parent_name ? &parent_name : NULL),
175 (parent_name ? 1 : 0), gpio, active_low, flags,
176 &clk_gpio_gate_ops);
177}
c873d14d
JS
178EXPORT_SYMBOL_GPL(clk_register_gpio_gate);
179
80eeb1f0
SS
180/**
181 * clk_register_gpio_mux - register a gpio clock mux with the clock framework
182 * @dev: device that is registering this clock
183 * @name: name of this clock
184 * @parent_names: names of this clock's parents
185 * @num_parents: number of parents listed in @parent_names
186 * @gpio: gpio number to gate this clock
187 * @active_low: true if gpio should be set to 0 to enable clock
188 * @flags: clock flags
189 */
190struct clk *clk_register_gpio_mux(struct device *dev, const char *name,
37bff2c1 191 const char * const *parent_names, u8 num_parents, unsigned gpio,
80eeb1f0
SS
192 bool active_low, unsigned long flags)
193{
194 if (num_parents != 2) {
195 pr_err("mux-clock %s must have 2 parents\n", name);
196 return ERR_PTR(-EINVAL);
197 }
198
199 return clk_register_gpio(dev, name, parent_names, num_parents,
200 gpio, active_low, flags, &clk_gpio_mux_ops);
201}
202EXPORT_SYMBOL_GPL(clk_register_gpio_mux);
203
c873d14d
JS
204#ifdef CONFIG_OF
205/**
80eeb1f0 206 * clk_register_get() has to be delayed, because -EPROBE_DEFER
c873d14d
JS
207 * can not be handled properly at of_clk_init() call time.
208 */
209
80eeb1f0
SS
210struct clk_gpio_delayed_register_data {
211 const char *gpio_name;
c873d14d
JS
212 struct device_node *node;
213 struct mutex lock;
214 struct clk *clk;
80eeb1f0 215 struct clk *(*clk_register_get)(const char *name,
37bff2c1 216 const char * const *parent_names, u8 num_parents,
80eeb1f0 217 unsigned gpio, bool active_low);
c873d14d
JS
218};
219
80eeb1f0
SS
220static struct clk *of_clk_gpio_delayed_register_get(
221 struct of_phandle_args *clkspec, void *_data)
c873d14d 222{
80eeb1f0 223 struct clk_gpio_delayed_register_data *data = _data;
c873d14d 224 struct clk *clk;
80eeb1f0
SS
225 const char **parent_names;
226 int i, num_parents;
c873d14d 227 int gpio;
820ad975 228 enum of_gpio_flags of_flags;
c873d14d
JS
229
230 mutex_lock(&data->lock);
231
232 if (data->clk) {
233 mutex_unlock(&data->lock);
234 return data->clk;
235 }
236
80eeb1f0
SS
237 gpio = of_get_named_gpio_flags(data->node, data->gpio_name, 0,
238 &of_flags);
c873d14d
JS
239 if (gpio < 0) {
240 mutex_unlock(&data->lock);
80eeb1f0
SS
241 if (gpio == -EPROBE_DEFER)
242 pr_debug("%s: %s: GPIOs not yet available, retry later\n",
243 data->node->name, __func__);
244 else
245 pr_err("%s: %s: Can't get '%s' DT property\n",
246 data->node->name, __func__,
247 data->gpio_name);
c873d14d
JS
248 return ERR_PTR(gpio);
249 }
c873d14d 250
80eeb1f0 251 num_parents = of_clk_get_parent_count(data->node);
c873d14d 252
80eeb1f0 253 parent_names = kcalloc(num_parents, sizeof(char *), GFP_KERNEL);
c5e857a4
SB
254 if (!parent_names) {
255 clk = ERR_PTR(-ENOMEM);
256 goto out;
257 }
80eeb1f0
SS
258
259 for (i = 0; i < num_parents; i++)
260 parent_names[i] = of_clk_get_parent_name(data->node, i);
261
262 clk = data->clk_register_get(data->node->name, parent_names,
263 num_parents, gpio, of_flags & OF_GPIO_ACTIVE_LOW);
264 if (IS_ERR(clk))
265 goto out;
c873d14d
JS
266
267 data->clk = clk;
80eeb1f0 268out:
c873d14d 269 mutex_unlock(&data->lock);
80eeb1f0 270 kfree(parent_names);
c873d14d
JS
271
272 return clk;
273}
274
80eeb1f0 275static struct clk *of_clk_gpio_gate_delayed_register_get(const char *name,
37bff2c1 276 const char * const *parent_names, u8 num_parents,
80eeb1f0
SS
277 unsigned gpio, bool active_low)
278{
279 return clk_register_gpio_gate(NULL, name, parent_names[0],
280 gpio, active_low, 0);
281}
282
283static struct clk *of_clk_gpio_mux_delayed_register_get(const char *name,
37bff2c1 284 const char * const *parent_names, u8 num_parents, unsigned gpio,
80eeb1f0
SS
285 bool active_low)
286{
287 return clk_register_gpio_mux(NULL, name, parent_names, num_parents,
288 gpio, active_low, 0);
289}
290
291static void __init of_gpio_clk_setup(struct device_node *node,
292 const char *gpio_name,
293 struct clk *(*clk_register_get)(const char *name,
37bff2c1
SB
294 const char * const *parent_names,
295 u8 num_parents,
80eeb1f0 296 unsigned gpio, bool active_low))
c873d14d 297{
80eeb1f0 298 struct clk_gpio_delayed_register_data *data;
c873d14d 299
80eeb1f0 300 data = kzalloc(sizeof(*data), GFP_KERNEL);
c873d14d
JS
301 if (!data)
302 return;
303
304 data->node = node;
80eeb1f0
SS
305 data->gpio_name = gpio_name;
306 data->clk_register_get = clk_register_get;
c873d14d
JS
307 mutex_init(&data->lock);
308
80eeb1f0
SS
309 of_clk_add_provider(node, of_clk_gpio_delayed_register_get, data);
310}
311
312static void __init of_gpio_gate_clk_setup(struct device_node *node)
313{
314 of_gpio_clk_setup(node, "enable-gpios",
315 of_clk_gpio_gate_delayed_register_get);
c873d14d 316}
c873d14d 317CLK_OF_DECLARE(gpio_gate_clk, "gpio-gate-clock", of_gpio_gate_clk_setup);
80eeb1f0
SS
318
319void __init of_gpio_mux_clk_setup(struct device_node *node)
320{
321 of_gpio_clk_setup(node, "select-gpios",
322 of_clk_gpio_mux_delayed_register_get);
323}
324CLK_OF_DECLARE(gpio_mux_clk, "gpio-mux-clock", of_gpio_mux_clk_setup);
c873d14d 325#endif