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v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - https://www.ti.com
  4 *
  5 * Authors:
  6 *    Jyri Sarha <jsarha@ti.com>
  7 *    Sergej Sawazki <ce3a@gmx.de>
  8 *
 
 
 
 
  9 * Gpio controlled clock implementation
 10 */
 11
 12#include <linux/clk-provider.h>
 13#include <linux/export.h>
 14#include <linux/slab.h>
 
 15#include <linux/gpio/consumer.h>
 
 16#include <linux/err.h>
 17#include <linux/device.h>
 18#include <linux/of.h>
 19#include <linux/platform_device.h>
 20#include <linux/regulator/consumer.h>
 21
 22/**
 23 * DOC: basic gpio gated clock which can be enabled and disabled
 24 *      with gpio output
 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
 31 */
 32
 33/**
 34 * struct clk_gpio - gpio gated clock
 35 *
 36 * @hw:		handle between common and hardware-specific interfaces
 37 * @gpiod:	gpio descriptor
 38 *
 39 * Clock with a gpio control for enabling and disabling the parent clock
 40 * or switching between two parents by asserting or deasserting the gpio.
 41 *
 42 * Implements .enable, .disable and .is_enabled or
 43 * .get_parent, .set_parent and .determine_rate depending on which clk_ops
 44 * is used.
 45 */
 46struct clk_gpio {
 47	struct clk_hw	hw;
 48	struct gpio_desc *gpiod;
 49};
 50
 51#define to_clk_gpio(_hw) container_of(_hw, struct clk_gpio, hw)
 52
 53static int clk_gpio_gate_enable(struct clk_hw *hw)
 54{
 55	struct clk_gpio *clk = to_clk_gpio(hw);
 56
 57	gpiod_set_value(clk->gpiod, 1);
 58
 59	return 0;
 60}
 61
 62static void clk_gpio_gate_disable(struct clk_hw *hw)
 63{
 64	struct clk_gpio *clk = to_clk_gpio(hw);
 65
 66	gpiod_set_value(clk->gpiod, 0);
 67}
 68
 69static int clk_gpio_gate_is_enabled(struct clk_hw *hw)
 70{
 71	struct clk_gpio *clk = to_clk_gpio(hw);
 72
 73	return gpiod_get_value(clk->gpiod);
 74}
 75
 76static const struct clk_ops clk_gpio_gate_ops = {
 77	.enable = clk_gpio_gate_enable,
 78	.disable = clk_gpio_gate_disable,
 79	.is_enabled = clk_gpio_gate_is_enabled,
 80};
 81
 82static int clk_sleeping_gpio_gate_prepare(struct clk_hw *hw)
 83{
 84	struct clk_gpio *clk = to_clk_gpio(hw);
 85
 86	gpiod_set_value_cansleep(clk->gpiod, 1);
 87
 88	return 0;
 89}
 90
 91static void clk_sleeping_gpio_gate_unprepare(struct clk_hw *hw)
 92{
 93	struct clk_gpio *clk = to_clk_gpio(hw);
 94
 95	gpiod_set_value_cansleep(clk->gpiod, 0);
 96}
 97
 98static int clk_sleeping_gpio_gate_is_prepared(struct clk_hw *hw)
 99{
100	struct clk_gpio *clk = to_clk_gpio(hw);
101
102	return gpiod_get_value_cansleep(clk->gpiod);
103}
104
105static const struct clk_ops clk_sleeping_gpio_gate_ops = {
106	.prepare = clk_sleeping_gpio_gate_prepare,
107	.unprepare = clk_sleeping_gpio_gate_unprepare,
108	.is_prepared = clk_sleeping_gpio_gate_is_prepared,
109};
110
111/**
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
117 */
118
119static u8 clk_gpio_mux_get_parent(struct clk_hw *hw)
120{
121	struct clk_gpio *clk = to_clk_gpio(hw);
122
123	return gpiod_get_value_cansleep(clk->gpiod);
124}
125
126static int clk_gpio_mux_set_parent(struct clk_hw *hw, u8 index)
127{
128	struct clk_gpio *clk = to_clk_gpio(hw);
129
130	gpiod_set_value_cansleep(clk->gpiod, index);
131
132	return 0;
133}
134
135static const struct clk_ops clk_gpio_mux_ops = {
136	.get_parent = clk_gpio_mux_get_parent,
137	.set_parent = clk_gpio_mux_set_parent,
138	.determine_rate = __clk_mux_determine_rate,
139};
 
140
141static struct clk_hw *clk_register_gpio(struct device *dev, u8 num_parents,
142					struct gpio_desc *gpiod,
143					const struct clk_ops *clk_gpio_ops)
 
144{
145	struct clk_gpio *clk_gpio;
146	struct clk_hw *hw;
147	struct clk_init_data init = {};
 
148	int err;
149	const struct clk_parent_data gpio_parent_data[] = {
150		{ .index = 0 },
151		{ .index = 1 },
152	};
153
154	clk_gpio = devm_kzalloc(dev, sizeof(*clk_gpio),	GFP_KERNEL);
 
 
 
 
155	if (!clk_gpio)
156		return ERR_PTR(-ENOMEM);
157
158	init.name = dev->of_node->name;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
159	init.ops = clk_gpio_ops;
160	init.parent_data = gpio_parent_data;
 
161	init.num_parents = num_parents;
162	init.flags = CLK_SET_RATE_PARENT;
163
164	clk_gpio->gpiod = gpiod;
165	clk_gpio->hw.init = &init;
166
167	hw = &clk_gpio->hw;
168	err = devm_clk_hw_register(dev, hw);
169	if (err)
170		return ERR_PTR(err);
 
171
172	return hw;
 
 
 
 
 
 
 
 
173}
174
175static struct clk_hw *clk_hw_register_gpio_gate(struct device *dev,
176						int num_parents,
177						struct gpio_desc *gpiod)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
178{
179	const struct clk_ops *ops;
180
181	if (gpiod_cansleep(gpiod))
182		ops = &clk_sleeping_gpio_gate_ops;
183	else
184		ops = &clk_gpio_gate_ops;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
185
186	return clk_register_gpio(dev, num_parents, gpiod, ops);
 
187}
 
188
189static struct clk_hw *clk_hw_register_gpio_mux(struct device *dev,
190					       struct gpio_desc *gpiod)
 
191{
192	return clk_register_gpio(dev, 2, gpiod, &clk_gpio_mux_ops);
 
 
 
 
 
 
193}
 
194
195static int gpio_clk_driver_probe(struct platform_device *pdev)
196{
197	struct device *dev = &pdev->dev;
198	struct device_node *node = dev->of_node;
199	const char *gpio_name;
200	unsigned int num_parents;
201	struct gpio_desc *gpiod;
202	struct clk_hw *hw;
203	bool is_mux;
 
 
 
 
 
 
 
 
 
 
 
 
 
204
205	is_mux = of_device_is_compatible(node, "gpio-mux-clock");
206
207	num_parents = of_clk_get_parent_count(node);
208	if (is_mux && num_parents != 2) {
209		dev_err(dev, "mux-clock must have 2 parents\n");
210		return -EINVAL;
 
 
 
 
 
 
 
211	}
212
213	gpio_name = is_mux ? "select" : "enable";
214	gpiod = devm_gpiod_get(dev, gpio_name, GPIOD_OUT_LOW);
215	if (IS_ERR(gpiod))
216		return dev_err_probe(dev, PTR_ERR(gpiod),
217				     "Can't get '%s' named GPIO property\n", gpio_name);
218
219	if (is_mux)
220		hw = clk_hw_register_gpio_mux(dev, gpiod);
 
221	else
222		hw = clk_hw_register_gpio_gate(dev, num_parents, gpiod);
223	if (IS_ERR(hw))
224		return PTR_ERR(hw);
 
 
225
226	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
227}
228
229static const struct of_device_id gpio_clk_match_table[] = {
230	{ .compatible = "gpio-mux-clock" },
231	{ .compatible = "gpio-gate-clock" },
232	{ }
233};
234
235static struct platform_driver gpio_clk_driver = {
236	.probe		= gpio_clk_driver_probe,
237	.driver		= {
238		.name	= "gpio-clk",
239		.of_match_table = gpio_clk_match_table,
240	},
241};
242builtin_platform_driver(gpio_clk_driver);
243
244/**
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
248 *           optionally a gpio that can sleep
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
252 */
253
254/**
255 * struct clk_gated_fixed - Gateable fixed rate clock
256 * @clk_gpio:	instance of clk_gpio for gate-gpio
257 * @supply:	supply regulator
258 * @rate:	fixed rate
259 */
260struct clk_gated_fixed {
261	struct clk_gpio clk_gpio;
262	struct regulator *supply;
263	unsigned long rate;
264};
265
266#define to_clk_gated_fixed(_clk_gpio) container_of(_clk_gpio, struct clk_gated_fixed, clk_gpio)
267
268static unsigned long clk_gated_fixed_recalc_rate(struct clk_hw *hw,
269						 unsigned long parent_rate)
270{
271	return to_clk_gated_fixed(to_clk_gpio(hw))->rate;
272}
273
274static int clk_gated_fixed_prepare(struct clk_hw *hw)
275{
276	struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw));
277
278	if (!clk->supply)
279		return 0;
280
281	return regulator_enable(clk->supply);
282}
283
284static void clk_gated_fixed_unprepare(struct clk_hw *hw)
285{
286	struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw));
287
288	if (!clk->supply)
289		return;
290
291	regulator_disable(clk->supply);
292}
293
294static int clk_gated_fixed_is_prepared(struct clk_hw *hw)
295{
296	struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw));
297
298	if (!clk->supply)
299		return true;
300
301	return regulator_is_enabled(clk->supply);
302}
303
304/*
305 * Fixed gated clock with non-sleeping gpio.
306 *
307 * Prepare operation turns on the supply regulator
308 * and the enable operation switches the enable-gpio.
309 */
310static const struct clk_ops clk_gated_fixed_ops = {
311	.prepare = clk_gated_fixed_prepare,
312	.unprepare = clk_gated_fixed_unprepare,
313	.is_prepared = clk_gated_fixed_is_prepared,
314	.enable = clk_gpio_gate_enable,
315	.disable = clk_gpio_gate_disable,
316	.is_enabled = clk_gpio_gate_is_enabled,
317	.recalc_rate = clk_gated_fixed_recalc_rate,
318};
319
320static int clk_sleeping_gated_fixed_prepare(struct clk_hw *hw)
321{
322	int ret;
323
324	ret = clk_gated_fixed_prepare(hw);
325	if (ret)
326		return ret;
327
328	ret = clk_sleeping_gpio_gate_prepare(hw);
329	if (ret)
330		clk_gated_fixed_unprepare(hw);
331
332	return ret;
333}
334
335static void clk_sleeping_gated_fixed_unprepare(struct clk_hw *hw)
336{
337	clk_gated_fixed_unprepare(hw);
338	clk_sleeping_gpio_gate_unprepare(hw);
339}
340
341/*
342 * Fixed gated clock with non-sleeping gpio.
343 *
344 * Enabling the supply regulator and switching the enable-gpio happens
345 * both in the prepare step.
346 * is_prepared only needs to check the gpio state, as toggling the
347 * gpio is the last step when preparing.
348 */
349static const struct clk_ops clk_sleeping_gated_fixed_ops = {
350	.prepare = clk_sleeping_gated_fixed_prepare,
351	.unprepare = clk_sleeping_gated_fixed_unprepare,
352	.is_prepared = clk_sleeping_gpio_gate_is_prepared,
353	.recalc_rate = clk_gated_fixed_recalc_rate,
354};
355
356static int clk_gated_fixed_probe(struct platform_device *pdev)
357{
358	struct device *dev = &pdev->dev;
359	struct clk_gated_fixed *clk;
360	const struct clk_ops *ops;
361	const char *clk_name;
362	u32 rate;
363	int ret;
364
365	clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL);
366	if (!clk)
367		return -ENOMEM;
368
369	ret = device_property_read_u32(dev, "clock-frequency", &rate);
370	if (ret)
371		return dev_err_probe(dev, ret, "Failed to get clock-frequency\n");
372	clk->rate = rate;
373
374	ret = device_property_read_string(dev, "clock-output-names", &clk_name);
375	if (ret)
376		clk_name = fwnode_get_name(dev->fwnode);
377
378	clk->supply = devm_regulator_get_optional(dev, "vdd");
379	if (IS_ERR(clk->supply)) {
380		if (PTR_ERR(clk->supply) != -ENODEV)
381			return dev_err_probe(dev, PTR_ERR(clk->supply),
382					     "Failed to get regulator\n");
383		clk->supply = NULL;
384	}
385
386	clk->clk_gpio.gpiod = devm_gpiod_get_optional(dev, "enable",
387						      GPIOD_OUT_LOW);
388	if (IS_ERR(clk->clk_gpio.gpiod))
389		return dev_err_probe(dev, PTR_ERR(clk->clk_gpio.gpiod),
390				     "Failed to get gpio\n");
391
392	if (gpiod_cansleep(clk->clk_gpio.gpiod))
393		ops = &clk_sleeping_gated_fixed_ops;
394	else
395		ops = &clk_gated_fixed_ops;
396
397	clk->clk_gpio.hw.init = CLK_HW_INIT_NO_PARENT(clk_name, ops, 0);
398
399	/* register the clock */
400	ret = devm_clk_hw_register(dev, &clk->clk_gpio.hw);
401	if (ret)
402		return dev_err_probe(dev, ret,
403				     "Failed to register clock\n");
404
405	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
406					  &clk->clk_gpio.hw);
407	if (ret)
408		return dev_err_probe(dev, ret,
409				     "Failed to register clock provider\n");
410
411	return 0;
412}
413
414static const struct of_device_id gated_fixed_clk_match_table[] = {
415	{ .compatible = "gated-fixed-clock" },
416	{ /* sentinel */ }
417};
418
419static struct platform_driver gated_fixed_clk_driver = {
420	.probe		= clk_gated_fixed_probe,
421	.driver		= {
422		.name	= "gated-fixed-clk",
423		.of_match_table = gated_fixed_clk_match_table,
424	},
425};
426builtin_platform_driver(gated_fixed_clk_driver);
v4.10.11
 
  1/*
  2 * Copyright (C) 2013 - 2014 Texas Instruments Incorporated - http://www.ti.com
  3 *
  4 * Authors:
  5 *    Jyri Sarha <jsarha@ti.com>
  6 *    Sergej Sawazki <ce3a@gmx.de>
  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 *
 12 * Gpio controlled clock implementation
 13 */
 14
 15#include <linux/clk-provider.h>
 16#include <linux/export.h>
 17#include <linux/slab.h>
 18#include <linux/gpio.h>
 19#include <linux/gpio/consumer.h>
 20#include <linux/of_gpio.h>
 21#include <linux/err.h>
 22#include <linux/device.h>
 
 23#include <linux/platform_device.h>
 24#include <linux/of_device.h>
 25
 26/**
 27 * DOC: basic gpio gated clock which can be enabled and disabled
 28 *      with gpio output
 29 * Traits of this clock:
 30 * prepare - clk_(un)prepare only ensures parent is (un)prepared
 31 * enable - clk_enable and clk_disable are functional & control gpio
 
 32 * rate - inherits rate from parent.  No clk_set_rate support
 33 * parent - fixed parent.  No clk_set_parent support
 34 */
 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/**
 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
 72 */
 73
 74static u8 clk_gpio_mux_get_parent(struct clk_hw *hw)
 75{
 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_hw *clk_register_gpio(struct device *dev, const char *name,
 98		const char * const *parent_names, u8 num_parents, unsigned gpio,
 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_hw *hw;
104	struct clk_init_data init = {};
105	unsigned long gpio_flags;
106	int err;
 
 
 
 
107
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
116	if (active_low)
117		gpio_flags = GPIOF_ACTIVE_LOW | GPIOF_OUT_INIT_HIGH;
118	else
119		gpio_flags = GPIOF_OUT_INIT_LOW;
120
121	if (dev)
122		err = devm_gpio_request_one(dev, gpio, gpio_flags, name);
123	else
124		err = gpio_request_one(gpio, gpio_flags, name);
125	if (err) {
126		if (err != -EPROBE_DEFER)
127			pr_err("%s: %s: Error requesting clock control gpio %u\n",
128					__func__, name, gpio);
129		if (!dev)
130			kfree(clk_gpio);
131
132		return ERR_PTR(err);
133	}
134
135	init.name = name;
136	init.ops = clk_gpio_ops;
137	init.flags = flags | CLK_IS_BASIC;
138	init.parent_names = parent_names;
139	init.num_parents = num_parents;
 
140
141	clk_gpio->gpiod = gpio_to_desc(gpio);
142	clk_gpio->hw.init = &init;
143
144	hw = &clk_gpio->hw;
145	if (dev)
146		err = devm_clk_hw_register(dev, hw);
147	else
148		err = clk_hw_register(NULL, hw);
149
150	if (!err)
151		return hw;
152
153	if (!dev) {
154		gpiod_put(clk_gpio->gpiod);
155		kfree(clk_gpio);
156	}
157
158	return ERR_PTR(err);
159}
160
161/**
162 * clk_hw_register_gpio_gate - register a gpio clock gate with the clock
163 * framework
164 * @dev: device that is registering this clock
165 * @name: name of this clock
166 * @parent_name: name of this clock's parent
167 * @gpio: gpio number to gate this clock
168 * @active_low: true if gpio should be set to 0 to enable clock
169 * @flags: clock flags
170 */
171struct clk_hw *clk_hw_register_gpio_gate(struct device *dev, const char *name,
172		const char *parent_name, unsigned gpio, bool active_low,
173		unsigned long flags)
174{
175	return clk_register_gpio(dev, name,
176			(parent_name ? &parent_name : NULL),
177			(parent_name ? 1 : 0), gpio, active_low, flags,
178			&clk_gpio_gate_ops);
179}
180EXPORT_SYMBOL_GPL(clk_hw_register_gpio_gate);
181
182struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
183		const char *parent_name, unsigned gpio, bool active_low,
184		unsigned long flags)
185{
186	struct clk_hw *hw;
187
188	hw = clk_hw_register_gpio_gate(dev, name, parent_name, gpio, active_low,
189				       flags);
190	if (IS_ERR(hw))
191		return ERR_CAST(hw);
192	return hw->clk;
193}
194EXPORT_SYMBOL_GPL(clk_register_gpio_gate);
195
196/**
197 * clk_hw_register_gpio_mux - register a gpio clock mux with the clock framework
198 * @dev: device that is registering this clock
199 * @name: name of this clock
200 * @parent_names: names of this clock's parents
201 * @num_parents: number of parents listed in @parent_names
202 * @gpio: gpio number to gate this clock
203 * @active_low: true if gpio should be set to 0 to enable clock
204 * @flags: clock flags
205 */
206struct clk_hw *clk_hw_register_gpio_mux(struct device *dev, const char *name,
207		const char * const *parent_names, u8 num_parents, unsigned gpio,
208		bool active_low, unsigned long flags)
209{
210	if (num_parents != 2) {
211		pr_err("mux-clock %s must have 2 parents\n", name);
212		return ERR_PTR(-EINVAL);
213	}
214
215	return clk_register_gpio(dev, name, parent_names, num_parents,
216			gpio, active_low, flags, &clk_gpio_mux_ops);
217}
218EXPORT_SYMBOL_GPL(clk_hw_register_gpio_mux);
219
220struct clk *clk_register_gpio_mux(struct device *dev, const char *name,
221		const char * const *parent_names, u8 num_parents, unsigned gpio,
222		bool active_low, unsigned long flags)
223{
224	struct clk_hw *hw;
225
226	hw = clk_hw_register_gpio_mux(dev, name, parent_names, num_parents,
227			gpio, active_low, flags);
228	if (IS_ERR(hw))
229		return ERR_CAST(hw);
230	return hw->clk;
231}
232EXPORT_SYMBOL_GPL(clk_register_gpio_mux);
233
234static int gpio_clk_driver_probe(struct platform_device *pdev)
235{
236	struct device_node *node = pdev->dev.of_node;
237	const char **parent_names, *gpio_name;
 
238	unsigned int num_parents;
239	int gpio;
240	enum of_gpio_flags of_flags;
241	struct clk *clk;
242	bool active_low, is_mux;
243
244	num_parents = of_clk_get_parent_count(node);
245	if (num_parents) {
246		parent_names = devm_kcalloc(&pdev->dev, num_parents,
247					    sizeof(char *), GFP_KERNEL);
248		if (!parent_names)
249			return -ENOMEM;
250
251		of_clk_parent_fill(node, parent_names, num_parents);
252	} else {
253		parent_names = NULL;
254	}
255
256	is_mux = of_device_is_compatible(node, "gpio-mux-clock");
257
258	gpio_name = is_mux ? "select-gpios" : "enable-gpios";
259	gpio = of_get_named_gpio_flags(node, gpio_name, 0, &of_flags);
260	if (gpio < 0) {
261		if (gpio == -EPROBE_DEFER)
262			pr_debug("%s: %s: GPIOs not yet available, retry later\n",
263					node->name, __func__);
264		else
265			pr_err("%s: %s: Can't get '%s' DT property\n",
266					node->name, __func__,
267					gpio_name);
268		return gpio;
269	}
270
271	active_low = of_flags & OF_GPIO_ACTIVE_LOW;
 
 
 
 
272
273	if (is_mux)
274		clk = clk_register_gpio_mux(&pdev->dev, node->name,
275				parent_names, num_parents, gpio, active_low, 0);
276	else
277		clk = clk_register_gpio_gate(&pdev->dev, node->name,
278				parent_names ?  parent_names[0] : NULL, gpio,
279				active_low, 0);
280	if (IS_ERR(clk))
281		return PTR_ERR(clk);
282
283	return of_clk_add_provider(node, of_clk_src_simple_get, clk);
284}
285
286static const struct of_device_id gpio_clk_match_table[] = {
287	{ .compatible = "gpio-mux-clock" },
288	{ .compatible = "gpio-gate-clock" },
289	{ }
290};
291
292static struct platform_driver gpio_clk_driver = {
293	.probe		= gpio_clk_driver_probe,
294	.driver		= {
295		.name	= "gpio-clk",
296		.of_match_table = gpio_clk_match_table,
297	},
298};
299builtin_platform_driver(gpio_clk_driver);