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/bits.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/regmap.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/regmap.h>
19
20 #include "gpiolib.h"
21
22 struct gpio_regmap {
23 struct device *parent;
24 struct regmap *regmap;
25 struct gpio_chip gpio_chip;
26
27 int reg_stride;
28 int ngpio_per_reg;
29 unsigned int reg_dat_base;
30 unsigned int reg_set_base;
31 unsigned int reg_clr_base;
32 unsigned int reg_dir_in_base;
33 unsigned int reg_dir_out_base;
34 unsigned long *fixed_direction_output;
35
36 #ifdef CONFIG_REGMAP_IRQ
37 int regmap_irq_line;
38 struct regmap_irq_chip_data *irq_chip_data;
39 #endif
40
41 int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
42 unsigned int offset, unsigned int *reg,
43 unsigned int *mask);
44
45 void *driver_data;
46 };
47
gpio_regmap_addr(unsigned int addr)48 static unsigned int gpio_regmap_addr(unsigned int addr)
49 {
50 if (addr == GPIO_REGMAP_ADDR_ZERO)
51 return 0;
52
53 return addr;
54 }
55
gpio_regmap_simple_xlate(struct gpio_regmap * gpio,unsigned int base,unsigned int offset,unsigned int * reg,unsigned int * mask)56 static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
57 unsigned int base, unsigned int offset,
58 unsigned int *reg, unsigned int *mask)
59 {
60 unsigned int line = offset % gpio->ngpio_per_reg;
61 unsigned int stride = offset / gpio->ngpio_per_reg;
62
63 *reg = base + stride * gpio->reg_stride;
64 *mask = BIT(line);
65
66 return 0;
67 }
68
gpio_regmap_get(struct gpio_chip * chip,unsigned int offset)69 static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
70 {
71 struct gpio_regmap *gpio = gpiochip_get_data(chip);
72 unsigned int base, val, reg, mask;
73 int ret;
74
75 /* we might not have an output register if we are input only */
76 if (gpio->reg_dat_base)
77 base = gpio_regmap_addr(gpio->reg_dat_base);
78 else
79 base = gpio_regmap_addr(gpio->reg_set_base);
80
81 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
82 if (ret)
83 return ret;
84
85 ret = regmap_read(gpio->regmap, reg, &val);
86 if (ret)
87 return ret;
88
89 return !!(val & mask);
90 }
91
gpio_regmap_set(struct gpio_chip * chip,unsigned int offset,int val)92 static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
93 int val)
94 {
95 struct gpio_regmap *gpio = gpiochip_get_data(chip);
96 unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
97 unsigned int reg, mask;
98 int ret;
99
100 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
101 if (ret)
102 return ret;
103
104 if (val)
105 ret = regmap_update_bits(gpio->regmap, reg, mask, mask);
106 else
107 ret = regmap_update_bits(gpio->regmap, reg, mask, 0);
108
109 return ret;
110 }
111
gpio_regmap_set_with_clear(struct gpio_chip * chip,unsigned int offset,int val)112 static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
113 unsigned int offset, int val)
114 {
115 struct gpio_regmap *gpio = gpiochip_get_data(chip);
116 unsigned int base, reg, mask;
117 int ret;
118
119 if (val)
120 base = gpio_regmap_addr(gpio->reg_set_base);
121 else
122 base = gpio_regmap_addr(gpio->reg_clr_base);
123
124 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
125 if (ret)
126 return ret;
127
128 return regmap_write(gpio->regmap, reg, mask);
129 }
130
gpio_regmap_get_direction(struct gpio_chip * chip,unsigned int offset)131 static int gpio_regmap_get_direction(struct gpio_chip *chip,
132 unsigned int offset)
133 {
134 struct gpio_regmap *gpio = gpiochip_get_data(chip);
135 unsigned int base, val, reg, mask;
136 int invert, ret;
137
138 if (gpio->fixed_direction_output) {
139 if (test_bit(offset, gpio->fixed_direction_output))
140 return GPIO_LINE_DIRECTION_OUT;
141 else
142 return GPIO_LINE_DIRECTION_IN;
143 }
144
145 if (gpio->reg_dat_base && !gpio->reg_set_base)
146 return GPIO_LINE_DIRECTION_IN;
147 if (gpio->reg_set_base && !gpio->reg_dat_base)
148 return GPIO_LINE_DIRECTION_OUT;
149
150 if (gpio->reg_dir_out_base) {
151 base = gpio_regmap_addr(gpio->reg_dir_out_base);
152 invert = 0;
153 } else if (gpio->reg_dir_in_base) {
154 base = gpio_regmap_addr(gpio->reg_dir_in_base);
155 invert = 1;
156 } else {
157 return -ENOTSUPP;
158 }
159
160 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
161 if (ret)
162 return ret;
163
164 ret = regmap_read(gpio->regmap, reg, &val);
165 if (ret)
166 return ret;
167
168 if (!!(val & mask) ^ invert)
169 return GPIO_LINE_DIRECTION_OUT;
170 else
171 return GPIO_LINE_DIRECTION_IN;
172 }
173
gpio_regmap_set_direction(struct gpio_chip * chip,unsigned int offset,bool output)174 static int gpio_regmap_set_direction(struct gpio_chip *chip,
175 unsigned int offset, bool output)
176 {
177 struct gpio_regmap *gpio = gpiochip_get_data(chip);
178 unsigned int base, val, reg, mask;
179 int invert, ret;
180
181 if (gpio->reg_dir_out_base) {
182 base = gpio_regmap_addr(gpio->reg_dir_out_base);
183 invert = 0;
184 } else if (gpio->reg_dir_in_base) {
185 base = gpio_regmap_addr(gpio->reg_dir_in_base);
186 invert = 1;
187 } else {
188 return -ENOTSUPP;
189 }
190
191 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
192 if (ret)
193 return ret;
194
195 if (invert)
196 val = output ? 0 : mask;
197 else
198 val = output ? mask : 0;
199
200 return regmap_update_bits(gpio->regmap, reg, mask, val);
201 }
202
gpio_regmap_direction_input(struct gpio_chip * chip,unsigned int offset)203 static int gpio_regmap_direction_input(struct gpio_chip *chip,
204 unsigned int offset)
205 {
206 return gpio_regmap_set_direction(chip, offset, false);
207 }
208
gpio_regmap_direction_output(struct gpio_chip * chip,unsigned int offset,int value)209 static int gpio_regmap_direction_output(struct gpio_chip *chip,
210 unsigned int offset, int value)
211 {
212 gpio_regmap_set(chip, offset, value);
213
214 return gpio_regmap_set_direction(chip, offset, true);
215 }
216
gpio_regmap_get_drvdata(struct gpio_regmap * gpio)217 void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
218 {
219 return gpio->driver_data;
220 }
221 EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
222
223 /**
224 * gpio_regmap_register() - Register a generic regmap GPIO controller
225 * @config: configuration for gpio_regmap
226 *
227 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
228 */
gpio_regmap_register(const struct gpio_regmap_config * config)229 struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
230 {
231 struct irq_domain *irq_domain;
232 struct gpio_regmap *gpio;
233 struct gpio_chip *chip;
234 int ret;
235
236 if (!config->parent)
237 return ERR_PTR(-EINVAL);
238
239 /* we need at least one */
240 if (!config->reg_dat_base && !config->reg_set_base)
241 return ERR_PTR(-EINVAL);
242
243 /* if we have a direction register we need both input and output */
244 if ((config->reg_dir_out_base || config->reg_dir_in_base) &&
245 (!config->reg_dat_base || !config->reg_set_base))
246 return ERR_PTR(-EINVAL);
247
248 /* we don't support having both registers simultaneously for now */
249 if (config->reg_dir_out_base && config->reg_dir_in_base)
250 return ERR_PTR(-EINVAL);
251
252 gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
253 if (!gpio)
254 return ERR_PTR(-ENOMEM);
255
256 gpio->parent = config->parent;
257 gpio->driver_data = config->drvdata;
258 gpio->regmap = config->regmap;
259 gpio->reg_dat_base = config->reg_dat_base;
260 gpio->reg_set_base = config->reg_set_base;
261 gpio->reg_clr_base = config->reg_clr_base;
262 gpio->reg_dir_in_base = config->reg_dir_in_base;
263 gpio->reg_dir_out_base = config->reg_dir_out_base;
264
265 chip = &gpio->gpio_chip;
266 chip->parent = config->parent;
267 chip->fwnode = config->fwnode;
268 chip->base = -1;
269 chip->names = config->names;
270 chip->label = config->label ?: dev_name(config->parent);
271 chip->can_sleep = regmap_might_sleep(config->regmap);
272 chip->init_valid_mask = config->init_valid_mask;
273
274 chip->request = gpiochip_generic_request;
275 chip->free = gpiochip_generic_free;
276 chip->get = gpio_regmap_get;
277 if (gpio->reg_set_base && gpio->reg_clr_base)
278 chip->set = gpio_regmap_set_with_clear;
279 else if (gpio->reg_set_base)
280 chip->set = gpio_regmap_set;
281
282 chip->get_direction = gpio_regmap_get_direction;
283 if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
284 chip->direction_input = gpio_regmap_direction_input;
285 chip->direction_output = gpio_regmap_direction_output;
286 }
287
288 chip->ngpio = config->ngpio;
289 if (!chip->ngpio) {
290 ret = gpiochip_get_ngpios(chip, chip->parent);
291 if (ret)
292 goto err_free_gpio;
293 }
294
295 if (config->fixed_direction_output) {
296 gpio->fixed_direction_output = bitmap_alloc(chip->ngpio,
297 GFP_KERNEL);
298 if (!gpio->fixed_direction_output) {
299 ret = -ENOMEM;
300 goto err_free_gpio;
301 }
302 bitmap_copy(gpio->fixed_direction_output,
303 config->fixed_direction_output, chip->ngpio);
304 }
305
306 /* if not set, assume there is only one register */
307 gpio->ngpio_per_reg = config->ngpio_per_reg;
308 if (!gpio->ngpio_per_reg)
309 gpio->ngpio_per_reg = config->ngpio;
310
311 /* if not set, assume they are consecutive */
312 gpio->reg_stride = config->reg_stride;
313 if (!gpio->reg_stride)
314 gpio->reg_stride = 1;
315
316 gpio->reg_mask_xlate = config->reg_mask_xlate;
317 if (!gpio->reg_mask_xlate)
318 gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
319
320 ret = gpiochip_add_data(chip, gpio);
321 if (ret < 0)
322 goto err_free_bitmap;
323
324 #ifdef CONFIG_REGMAP_IRQ
325 if (config->regmap_irq_chip) {
326 gpio->regmap_irq_line = config->regmap_irq_line;
327 ret = regmap_add_irq_chip_fwnode(dev_fwnode(config->parent), config->regmap,
328 config->regmap_irq_line, config->regmap_irq_flags,
329 0, config->regmap_irq_chip, &gpio->irq_chip_data);
330 if (ret)
331 goto err_free_bitmap;
332
333 irq_domain = regmap_irq_get_domain(gpio->irq_chip_data);
334 } else
335 #endif
336 irq_domain = config->irq_domain;
337
338 if (irq_domain) {
339 ret = gpiochip_irqchip_add_domain(chip, irq_domain);
340 if (ret)
341 goto err_remove_gpiochip;
342 }
343
344 return gpio;
345
346 err_remove_gpiochip:
347 gpiochip_remove(chip);
348 err_free_bitmap:
349 bitmap_free(gpio->fixed_direction_output);
350 err_free_gpio:
351 kfree(gpio);
352 return ERR_PTR(ret);
353 }
354 EXPORT_SYMBOL_GPL(gpio_regmap_register);
355
356 /**
357 * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
358 * @gpio: gpio_regmap device to unregister
359 */
gpio_regmap_unregister(struct gpio_regmap * gpio)360 void gpio_regmap_unregister(struct gpio_regmap *gpio)
361 {
362 #ifdef CONFIG_REGMAP_IRQ
363 if (gpio->irq_chip_data)
364 regmap_del_irq_chip(gpio->regmap_irq_line, gpio->irq_chip_data);
365 #endif
366
367 gpiochip_remove(&gpio->gpio_chip);
368 bitmap_free(gpio->fixed_direction_output);
369 kfree(gpio);
370 }
371 EXPORT_SYMBOL_GPL(gpio_regmap_unregister);
372
devm_gpio_regmap_unregister(void * res)373 static void devm_gpio_regmap_unregister(void *res)
374 {
375 gpio_regmap_unregister(res);
376 }
377
378 /**
379 * devm_gpio_regmap_register() - resource managed gpio_regmap_register()
380 * @dev: device that is registering this GPIO device
381 * @config: configuration for gpio_regmap
382 *
383 * Managed gpio_regmap_register(). For generic regmap GPIO device registered by
384 * this function, gpio_regmap_unregister() is automatically called on driver
385 * detach. See gpio_regmap_register() for more information.
386 *
387 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
388 */
devm_gpio_regmap_register(struct device * dev,const struct gpio_regmap_config * config)389 struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
390 const struct gpio_regmap_config *config)
391 {
392 struct gpio_regmap *gpio;
393 int ret;
394
395 gpio = gpio_regmap_register(config);
396
397 if (IS_ERR(gpio))
398 return gpio;
399
400 ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio);
401 if (ret)
402 return ERR_PTR(ret);
403
404 return gpio;
405 }
406 EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);
407
408 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
409 MODULE_DESCRIPTION("GPIO generic regmap driver core");
410 MODULE_LICENSE("GPL");
411