[linux-2.6-block.git] / drivers / gpio / gpio-regmap.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * regmap based generic GPIO driver
 *
 * Copyright 2020 Michael Walle <michael@walle.cc>
 */

#include <linux/gpio/driver.h>
#include <linux/gpio/regmap.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>

struct gpio_regmap {
	struct device *parent;
	struct regmap *regmap;
	struct gpio_chip gpio_chip;

	int reg_stride;
	int ngpio_per_reg;
	unsigned int reg_dat_base;
	unsigned int reg_set_base;
	unsigned int reg_clr_base;
	unsigned int reg_dir_in_base;
	unsigned int reg_dir_out_base;

	int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
			      unsigned int offset, unsigned int *reg,
			      unsigned int *mask);

	void *driver_data;
};

static unsigned int gpio_regmap_addr(unsigned int addr)
{
	if (addr == GPIO_REGMAP_ADDR_ZERO)
		return 0;

	return addr;
}

static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
				    unsigned int base, unsigned int offset,
				    unsigned int *reg, unsigned int *mask)
{
	unsigned int line = offset % gpio->ngpio_per_reg;
	unsigned int stride = offset / gpio->ngpio_per_reg;

	*reg = base + stride * gpio->reg_stride;
	*mask = BIT(line);

	return 0;
}

static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base, val, reg, mask;
	int ret;

	/* we might not have an output register if we are input only */
	if (gpio->reg_dat_base)
		base = gpio_regmap_addr(gpio->reg_dat_base);
	else
		base = gpio_regmap_addr(gpio->reg_set_base);

	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	if (ret)
		return ret;

	ret = regmap_read(gpio->regmap, reg, &val);
	if (ret)
		return ret;

	return !!(val & mask);
}

static void gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
			    int val)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
	unsigned int reg, mask;

	gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	if (val)
		regmap_update_bits(gpio->regmap, reg, mask, mask);
	else
		regmap_update_bits(gpio->regmap, reg, mask, 0);
}

static void gpio_regmap_set_with_clear(struct gpio_chip *chip,
				       unsigned int offset, int val)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base, reg, mask;

	if (val)
		base = gpio_regmap_addr(gpio->reg_set_base);
	else
		base = gpio_regmap_addr(gpio->reg_clr_base);

	gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	regmap_write(gpio->regmap, reg, mask);
}

static int gpio_regmap_get_direction(struct gpio_chip *chip,
				     unsigned int offset)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base, val, reg, mask;
	int invert, ret;

	if (gpio->reg_dir_out_base) {
		base = gpio_regmap_addr(gpio->reg_dir_out_base);
		invert = 0;
	} else if (gpio->reg_dir_in_base) {
		base = gpio_regmap_addr(gpio->reg_dir_in_base);
		invert = 1;
	} else {
		return -EOPNOTSUPP;
	}

	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	if (ret)
		return ret;

	ret = regmap_read(gpio->regmap, reg, &val);
	if (ret)
		return ret;

	if (!!(val & mask) ^ invert)
		return GPIO_LINE_DIRECTION_OUT;
	else
		return GPIO_LINE_DIRECTION_IN;
}

static int gpio_regmap_set_direction(struct gpio_chip *chip,
				     unsigned int offset, bool output)
{
	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	unsigned int base, val, reg, mask;
	int invert, ret;

	if (gpio->reg_dir_out_base) {
		base = gpio_regmap_addr(gpio->reg_dir_out_base);
		invert = 0;
	} else if (gpio->reg_dir_in_base) {
		base = gpio_regmap_addr(gpio->reg_dir_in_base);
		invert = 1;
	} else {
		return -EOPNOTSUPP;
	}

	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
	if (ret)
		return ret;

	if (invert)
		val = output ? 0 : mask;
	else
		val = output ? mask : 0;

	return regmap_update_bits(gpio->regmap, reg, mask, val);
}

static int gpio_regmap_direction_input(struct gpio_chip *chip,
				       unsigned int offset)
{
	return gpio_regmap_set_direction(chip, offset, false);
}

static int gpio_regmap_direction_output(struct gpio_chip *chip,
					unsigned int offset, int value)
{
	gpio_regmap_set(chip, offset, value);

	return gpio_regmap_set_direction(chip, offset, true);
}

void gpio_regmap_set_drvdata(struct gpio_regmap *gpio, void *data)
{
	gpio->driver_data = data;
}
EXPORT_SYMBOL_GPL(gpio_regmap_set_drvdata);

void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
{
	return gpio->driver_data;
}
EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);

/**
 * gpio_regmap_register() - Register a generic regmap GPIO controller
 * @config: configuration for gpio_regmap
 *
 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
 */
struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
{
	struct gpio_regmap *gpio;
	struct gpio_chip *chip;
	int ret;

	if (!config->parent)
		return ERR_PTR(-EINVAL);

	if (!config->ngpio)
		return ERR_PTR(-EINVAL);

	/* we need at least one */
	if (!config->reg_dat_base && !config->reg_set_base)
		return ERR_PTR(-EINVAL);

	/* if we have a direction register we need both input and output */
	if ((config->reg_dir_out_base || config->reg_dir_in_base) &&
	    (!config->reg_dat_base || !config->reg_set_base))
		return ERR_PTR(-EINVAL);

	/* we don't support having both registers simultaneously for now */
	if (config->reg_dir_out_base && config->reg_dir_in_base)
		return ERR_PTR(-EINVAL);

	gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
	if (!gpio)
		return ERR_PTR(-ENOMEM);

	gpio->parent = config->parent;
	gpio->regmap = config->regmap;
	gpio->ngpio_per_reg = config->ngpio_per_reg;
	gpio->reg_stride = config->reg_stride;
	gpio->reg_mask_xlate = config->reg_mask_xlate;
	gpio->reg_dat_base = config->reg_dat_base;
	gpio->reg_set_base = config->reg_set_base;
	gpio->reg_clr_base = config->reg_clr_base;
	gpio->reg_dir_in_base = config->reg_dir_in_base;
	gpio->reg_dir_out_base = config->reg_dir_out_base;

	/* if not set, assume there is only one register */
	if (!gpio->ngpio_per_reg)
		gpio->ngpio_per_reg = config->ngpio;

	/* if not set, assume they are consecutive */
	if (!gpio->reg_stride)
		gpio->reg_stride = 1;

	if (!gpio->reg_mask_xlate)
		gpio->reg_mask_xlate = gpio_regmap_simple_xlate;

	chip = &gpio->gpio_chip;
	chip->parent = config->parent;
	chip->base = -1;
	chip->ngpio = config->ngpio;
	chip->names = config->names;
	chip->label = config->label ?: dev_name(config->parent);

	/*
	 * If our regmap is fast_io we should probably set can_sleep to false.
	 * Right now, the regmap doesn't save this property, nor is there any
	 * access function for it.
	 * The only regmap type which uses fast_io is regmap-mmio. For now,
	 * assume a safe default of true here.
	 */
	chip->can_sleep = true;

	chip->get = gpio_regmap_get;
	if (gpio->reg_set_base && gpio->reg_clr_base)
		chip->set = gpio_regmap_set_with_clear;
	else if (gpio->reg_set_base)
		chip->set = gpio_regmap_set;

	if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
		chip->get_direction = gpio_regmap_get_direction;
		chip->direction_input = gpio_regmap_direction_input;
		chip->direction_output = gpio_regmap_direction_output;
	}

	ret = gpiochip_add_data(chip, gpio);
	if (ret < 0)
		goto err_free_gpio;

	if (config->irq_domain) {
		ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
		if (ret)
			goto err_remove_gpiochip;
	}

	return gpio;

err_remove_gpiochip:
	gpiochip_remove(chip);
err_free_gpio:
	kfree(gpio);
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(gpio_regmap_register);

/**
 * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
 * @gpio: gpio_regmap device to unregister
 */
void gpio_regmap_unregister(struct gpio_regmap *gpio)
{
	gpiochip_remove(&gpio->gpio_chip);
	kfree(gpio);
}
EXPORT_SYMBOL_GPL(gpio_regmap_unregister);

static void devm_gpio_regmap_unregister(struct device *dev, void *res)
{
	gpio_regmap_unregister(*(struct gpio_regmap **)res);
}

/**
 * devm_gpio_regmap_register() - resource managed gpio_regmap_register()
 * @dev: device that is registering this GPIO device
 * @config: configuration for gpio_regmap
 *
 * Managed gpio_regmap_register(). For generic regmap GPIO device registered by
 * this function, gpio_regmap_unregister() is automatically called on driver
 * detach. See gpio_regmap_register() for more information.
 *
 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
 */
struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
					      const struct gpio_regmap_config *config)
{
	struct gpio_regmap **ptr, *gpio;

	ptr = devres_alloc(devm_gpio_regmap_unregister, sizeof(*ptr),
			   GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	gpio = gpio_regmap_register(config);
	if (!IS_ERR(gpio)) {
		*ptr = gpio;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return gpio;
}
EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);

MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
MODULE_DESCRIPTION("GPIO generic regmap driver core");
MODULE_LICENSE("GPL");
Commit	Line	Data
ebe36319 MW	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* regmap based generic GPIO driver
	4	*
	5	* Copyright 2020 Michael Walle <michael@walle.cc>
	6	*/
	7
	8	#include <linux/gpio/driver.h>
	9	#include <linux/gpio/regmap.h>
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/regmap.h>
	13
	14	struct gpio_regmap {
	15	struct device *parent;
	16	struct regmap *regmap;
	17	struct gpio_chip gpio_chip;
	18
	19	int reg_stride;
	20	int ngpio_per_reg;
	21	unsigned int reg_dat_base;
	22	unsigned int reg_set_base;
	23	unsigned int reg_clr_base;
	24	unsigned int reg_dir_in_base;
	25	unsigned int reg_dir_out_base;
	26
	27	int (reg_mask_xlate)(struct gpio_regmap gpio, unsigned int base,
	28	unsigned int offset, unsigned int *reg,
	29	unsigned int *mask);
	30
	31	void *driver_data;
	32	};
	33
	34	static unsigned int gpio_regmap_addr(unsigned int addr)
	35	{
	36	if (addr == GPIO_REGMAP_ADDR_ZERO)
	37	return 0;
	38
	39	return addr;
	40	}
	41
	42	static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
	43	unsigned int base, unsigned int offset,
	44	unsigned int reg, unsigned int mask)
	45	{
	46	unsigned int line = offset % gpio->ngpio_per_reg;
	47	unsigned int stride = offset / gpio->ngpio_per_reg;
	48
	49	reg = base + stride gpio->reg_stride;
	50	*mask = BIT(line);
	51
	52	return 0;
	53	}
	54
	55	static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
	56	{
	57	struct gpio_regmap *gpio = gpiochip_get_data(chip);
	58	unsigned int base, val, reg, mask;
	59	int ret;
	60
	61	/* we might not have an output register if we are input only */
	62	if (gpio->reg_dat_base)
	63	base = gpio_regmap_addr(gpio->reg_dat_base);
	64	else
65	base = gpio_regmap_addr(gpio->reg_set_base);
66
67	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
68	if (ret)
69	return ret;
70
71	ret = regmap_read(gpio->regmap, reg, &val);
72	if (ret)
73	return ret;
74
75	return !!(val & mask);
76	}
77
78	static void gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
79	int val)
80	{
81	struct gpio_regmap *gpio = gpiochip_get_data(chip);
82	unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
83	unsigned int reg, mask;
84
85	gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
86	if (val)
87	regmap_update_bits(gpio->regmap, reg, mask, mask);
88	else
89	regmap_update_bits(gpio->regmap, reg, mask, 0);
90	}
91
92	static void gpio_regmap_set_with_clear(struct gpio_chip *chip,
93	unsigned int offset, int val)
94	{
95	struct gpio_regmap *gpio = gpiochip_get_data(chip);
96	unsigned int base, reg, mask;
97
98	if (val)
99	base = gpio_regmap_addr(gpio->reg_set_base);
100	else
101	base = gpio_regmap_addr(gpio->reg_clr_base);
102
103	gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
104	regmap_write(gpio->regmap, reg, mask);
105	}
106
107	static int gpio_regmap_get_direction(struct gpio_chip *chip,
108	unsigned int offset)
109	{
110	struct gpio_regmap *gpio = gpiochip_get_data(chip);
111	unsigned int base, val, reg, mask;
112	int invert, ret;
113
114	if (gpio->reg_dir_out_base) {
115	base = gpio_regmap_addr(gpio->reg_dir_out_base);
116	invert = 0;
117	} else if (gpio->reg_dir_in_base) {
118	base = gpio_regmap_addr(gpio->reg_dir_in_base);
119	invert = 1;
120	} else {
121	return -EOPNOTSUPP;
122	}
123
124	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
125	if (ret)
126	return ret;
127
128	ret = regmap_read(gpio->regmap, reg, &val);
129	if (ret)
130	return ret;
131
132	if (!!(val & mask) ^ invert)
133	return GPIO_LINE_DIRECTION_OUT;
134	else
135	return GPIO_LINE_DIRECTION_IN;
136	}
137
138	static int gpio_regmap_set_direction(struct gpio_chip *chip,
139	unsigned int offset, bool output)
140	{
141	struct gpio_regmap *gpio = gpiochip_get_data(chip);
142	unsigned int base, val, reg, mask;
143	int invert, ret;
144
145	if (gpio->reg_dir_out_base) {
146	base = gpio_regmap_addr(gpio->reg_dir_out_base);
147	invert = 0;
148	} else if (gpio->reg_dir_in_base) {
149	base = gpio_regmap_addr(gpio->reg_dir_in_base);
150	invert = 1;
151	} else {
152	return -EOPNOTSUPP;
153	}
154
155	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
156	if (ret)
157	return ret;
158
159	if (invert)
160	val = output ? 0 : mask;
161	else
162	val = output ? mask : 0;
163
164	return regmap_update_bits(gpio->regmap, reg, mask, val);
165	}
166
167	static int gpio_regmap_direction_input(struct gpio_chip *chip,
168	unsigned int offset)
169	{
170	return gpio_regmap_set_direction(chip, offset, false);
171	}
172
173	static int gpio_regmap_direction_output(struct gpio_chip *chip,
174	unsigned int offset, int value)
175	{
176	gpio_regmap_set(chip, offset, value);
177
178	return gpio_regmap_set_direction(chip, offset, true);
179	}
180
181	void gpio_regmap_set_drvdata(struct gpio_regmap gpio, void data)
182	{
183	gpio->driver_data = data;
184	}
185	EXPORT_SYMBOL_GPL(gpio_regmap_set_drvdata);
186
187	void gpio_regmap_get_drvdata(struct gpio_regmap gpio)
188	{
189	return gpio->driver_data;
190	}
191	EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
192
193	/**
194	* gpio_regmap_register() - Register a generic regmap GPIO controller
195	* @config: configuration for gpio_regmap
196	*
197	* Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
198	*/
199	struct gpio_regmap gpio_regmap_register(const struct gpio_regmap_config config)
200	{
201	struct gpio_regmap *gpio;
202	struct gpio_chip *chip;
203	int ret;
204
205	if (!config->parent)
206	return ERR_PTR(-EINVAL);
207
208	if (!config->ngpio)
209	return ERR_PTR(-EINVAL);
210
211	/* we need at least one */
212	if (!config->reg_dat_base && !config->reg_set_base)
213	return ERR_PTR(-EINVAL);
214
215	/* if we have a direction register we need both input and output */
216	if ((config->reg_dir_out_base \|\| config->reg_dir_in_base) &&
217	(!config->reg_dat_base \|\| !config->reg_set_base))
218	return ERR_PTR(-EINVAL);
219
220	/* we don't support having both registers simultaneously for now */
221	if (config->reg_dir_out_base && config->reg_dir_in_base)
222	return ERR_PTR(-EINVAL);
223
224	gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
225	if (!gpio)
226	return ERR_PTR(-ENOMEM);
227
228	gpio->parent = config->parent;
229	gpio->regmap = config->regmap;
230	gpio->ngpio_per_reg = config->ngpio_per_reg;
231	gpio->reg_stride = config->reg_stride;
232	gpio->reg_mask_xlate = config->reg_mask_xlate;
233	gpio->reg_dat_base = config->reg_dat_base;
234	gpio->reg_set_base = config->reg_set_base;
235	gpio->reg_clr_base = config->reg_clr_base;
236	gpio->reg_dir_in_base = config->reg_dir_in_base;
237	gpio->reg_dir_out_base = config->reg_dir_out_base;
238
239	/* if not set, assume there is only one register */
240	if (!gpio->ngpio_per_reg)
241	gpio->ngpio_per_reg = config->ngpio;
242
243	/* if not set, assume they are consecutive */
244	if (!gpio->reg_stride)
245	gpio->reg_stride = 1;
246
247	if (!gpio->reg_mask_xlate)
248	gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
249
250	chip = &gpio->gpio_chip;
251	chip->parent = config->parent;
252	chip->base = -1;
253	chip->ngpio = config->ngpio;
254	chip->names = config->names;
255	chip->label = config->label ?: dev_name(config->parent);
256
257	/*
258	* If our regmap is fast_io we should probably set can_sleep to false.
259	* Right now, the regmap doesn't save this property, nor is there any
260	* access function for it.
261	* The only regmap type which uses fast_io is regmap-mmio. For now,
262	* assume a safe default of true here.
263	*/
264	chip->can_sleep = true;
265
266	chip->get = gpio_regmap_get;
267	if (gpio->reg_set_base && gpio->reg_clr_base)
268	chip->set = gpio_regmap_set_with_clear;
269	else if (gpio->reg_set_base)
270	chip->set = gpio_regmap_set;
271
272	if (gpio->reg_dir_in_base \|\| gpio->reg_dir_out_base) {
273	chip->get_direction = gpio_regmap_get_direction;
274	chip->direction_input = gpio_regmap_direction_input;
275	chip->direction_output = gpio_regmap_direction_output;
276	}
277
278	ret = gpiochip_add_data(chip, gpio);
279	if (ret < 0)
280	goto err_free_gpio;
281
282	if (config->irq_domain) {
283	ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
284	if (ret)
285	goto err_remove_gpiochip;
286	}
287
288	return gpio;
289
290	err_remove_gpiochip:
291	gpiochip_remove(chip);
292	err_free_gpio:
293	kfree(gpio);
294	return ERR_PTR(ret);
295	}
296	EXPORT_SYMBOL_GPL(gpio_regmap_register);
297
298	/**
299	* gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
300	* @gpio: gpio_regmap device to unregister
301	*/
302	void gpio_regmap_unregister(struct gpio_regmap *gpio)
303	{
304	gpiochip_remove(&gpio->gpio_chip);
305	kfree(gpio);
306	}
307	EXPORT_SYMBOL_GPL(gpio_regmap_unregister);
308
309	static void devm_gpio_regmap_unregister(struct device dev, void res)
310	{
311	gpio_regmap_unregister((struct gpio_regmap *)res);
312	}
313
314	/**
315	* devm_gpio_regmap_register() - resource managed gpio_regmap_register()
316	* @dev: device that is registering this GPIO device
317	* @config: configuration for gpio_regmap
318	*
319	* Managed gpio_regmap_register(). For generic regmap GPIO device registered by
320	* this function, gpio_regmap_unregister() is automatically called on driver
321	* detach. See gpio_regmap_register() for more information.
322	*
323	* Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
324	*/
325	struct gpio_regmap devm_gpio_regmap_register(struct device dev,
326	const struct gpio_regmap_config *config)
327	{
328	struct gpio_regmap *ptr, gpio;
329
330	ptr = devres_alloc(devm_gpio_regmap_unregister, sizeof(*ptr),
331	GFP_KERNEL);
332	if (!ptr)
333	return ERR_PTR(-ENOMEM);
334
335	gpio = gpio_regmap_register(config);
336	if (!IS_ERR(gpio)) {
337	*ptr = gpio;
338	devres_add(dev, ptr);
339	} else {
340	devres_free(ptr);
341	}
342
343	return gpio;
344	}
345	EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);
346
347	MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
348	MODULE_DESCRIPTION("GPIO generic regmap driver core");
349	MODULE_LICENSE("GPL");