1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * AXP20x pinctrl and GPIO driver
4  *
5  * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com>
6  * Copyright (C) 2017 Quentin Schulz <quentin.schulz@free-electrons.com>
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/device.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/mfd/axp20x.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_device.h>
19 #include <linux/pinctrl/pinconf-generic.h>
20 #include <linux/pinctrl/pinctrl.h>
21 #include <linux/pinctrl/pinmux.h>
22 #include <linux/platform_device.h>
23 #include <linux/regmap.h>
24 #include <linux/slab.h>
25 
26 #define AXP20X_GPIO_FUNCTIONS		0x7
27 #define AXP20X_GPIO_FUNCTION_OUT_LOW	0
28 #define AXP20X_GPIO_FUNCTION_OUT_HIGH	1
29 #define AXP20X_GPIO_FUNCTION_INPUT	2
30 
31 #define AXP20X_FUNC_GPIO_OUT		0
32 #define AXP20X_FUNC_GPIO_IN		1
33 #define AXP20X_FUNC_LDO			2
34 #define AXP20X_FUNC_ADC			3
35 #define AXP20X_FUNCS_NB			4
36 
37 #define AXP20X_MUX_GPIO_OUT		0
38 #define AXP20X_MUX_GPIO_IN		BIT(1)
39 #define AXP20X_MUX_ADC			BIT(2)
40 
41 #define AXP813_MUX_ADC			(BIT(2) | BIT(0))
42 
43 struct axp20x_pctrl_desc {
44 	const struct pinctrl_pin_desc	*pins;
45 	unsigned int			npins;
46 	/* Stores the pins supporting LDO function. Bit offset is pin number. */
47 	u8				ldo_mask;
48 	/* Stores the pins supporting ADC function. Bit offset is pin number. */
49 	u8				adc_mask;
50 	u8				gpio_status_offset;
51 	u8				adc_mux;
52 };
53 
54 struct axp20x_pinctrl_function {
55 	const char	*name;
56 	unsigned int	muxval;
57 	const char	**groups;
58 	unsigned int	ngroups;
59 };
60 
61 struct axp20x_pctl {
62 	struct gpio_chip	chip;
63 	struct regmap		*regmap;
64 	struct pinctrl_dev			*pctl_dev;
65 	struct device				*dev;
66 	const struct axp20x_pctrl_desc		*desc;
67 	struct axp20x_pinctrl_function		funcs[AXP20X_FUNCS_NB];
68 };
69 
70 static const struct pinctrl_pin_desc axp209_pins[] = {
71 	PINCTRL_PIN(0, "GPIO0"),
72 	PINCTRL_PIN(1, "GPIO1"),
73 	PINCTRL_PIN(2, "GPIO2"),
74 };
75 
76 static const struct pinctrl_pin_desc axp813_pins[] = {
77 	PINCTRL_PIN(0, "GPIO0"),
78 	PINCTRL_PIN(1, "GPIO1"),
79 };
80 
81 static const struct axp20x_pctrl_desc axp20x_data = {
82 	.pins	= axp209_pins,
83 	.npins	= ARRAY_SIZE(axp209_pins),
84 	.ldo_mask = BIT(0) | BIT(1),
85 	.adc_mask = BIT(0) | BIT(1),
86 	.gpio_status_offset = 4,
87 	.adc_mux = AXP20X_MUX_ADC,
88 };
89 
90 static const struct axp20x_pctrl_desc axp813_data = {
91 	.pins	= axp813_pins,
92 	.npins	= ARRAY_SIZE(axp813_pins),
93 	.ldo_mask = BIT(0) | BIT(1),
94 	.adc_mask = BIT(0),
95 	.gpio_status_offset = 0,
96 	.adc_mux = AXP813_MUX_ADC,
97 };
98 
99 static int axp20x_gpio_get_reg(unsigned int offset)
100 {
101 	switch (offset) {
102 	case 0:
103 		return AXP20X_GPIO0_CTRL;
104 	case 1:
105 		return AXP20X_GPIO1_CTRL;
106 	case 2:
107 		return AXP20X_GPIO2_CTRL;
108 	}
109 
110 	return -EINVAL;
111 }
112 
113 static int axp20x_gpio_input(struct gpio_chip *chip, unsigned int offset)
114 {
115 	return pinctrl_gpio_direction_input(chip->base + offset);
116 }
117 
118 static int axp20x_gpio_get(struct gpio_chip *chip, unsigned int offset)
119 {
120 	struct axp20x_pctl *pctl = gpiochip_get_data(chip);
121 	unsigned int val;
122 	int ret;
123 
124 	ret = regmap_read(pctl->regmap, AXP20X_GPIO20_SS, &val);
125 	if (ret)
126 		return ret;
127 
128 	return !!(val & BIT(offset + pctl->desc->gpio_status_offset));
129 }
130 
131 static int axp20x_gpio_get_direction(struct gpio_chip *chip,
132 				     unsigned int offset)
133 {
134 	struct axp20x_pctl *pctl = gpiochip_get_data(chip);
135 	unsigned int val;
136 	int reg, ret;
137 
138 	reg = axp20x_gpio_get_reg(offset);
139 	if (reg < 0)
140 		return reg;
141 
142 	ret = regmap_read(pctl->regmap, reg, &val);
143 	if (ret)
144 		return ret;
145 
146 	/*
147 	 * This shouldn't really happen if the pin is in use already,
148 	 * or if it's not in use yet, it doesn't matter since we're
149 	 * going to change the value soon anyway. Default to output.
150 	 */
151 	if ((val & AXP20X_GPIO_FUNCTIONS) > 2)
152 		return 0;
153 
154 	/*
155 	 * The GPIO directions are the three lowest values.
156 	 * 2 is input, 0 and 1 are output
157 	 */
158 	return val & 2;
159 }
160 
161 static int axp20x_gpio_output(struct gpio_chip *chip, unsigned int offset,
162 			      int value)
163 {
164 	chip->set(chip, offset, value);
165 
166 	return 0;
167 }
168 
169 static void axp20x_gpio_set(struct gpio_chip *chip, unsigned int offset,
170 			    int value)
171 {
172 	struct axp20x_pctl *pctl = gpiochip_get_data(chip);
173 	int reg;
174 
175 	reg = axp20x_gpio_get_reg(offset);
176 	if (reg < 0)
177 		return;
178 
179 	regmap_update_bits(pctl->regmap, reg,
180 			   AXP20X_GPIO_FUNCTIONS,
181 			   value ? AXP20X_GPIO_FUNCTION_OUT_HIGH :
182 			   AXP20X_GPIO_FUNCTION_OUT_LOW);
183 }
184 
185 static int axp20x_pmx_set(struct pinctrl_dev *pctldev, unsigned int offset,
186 			  u8 config)
187 {
188 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
189 	int reg;
190 
191 	reg = axp20x_gpio_get_reg(offset);
192 	if (reg < 0)
193 		return reg;
194 
195 	return regmap_update_bits(pctl->regmap, reg, AXP20X_GPIO_FUNCTIONS,
196 				  config);
197 }
198 
199 static int axp20x_pmx_func_cnt(struct pinctrl_dev *pctldev)
200 {
201 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
202 
203 	return ARRAY_SIZE(pctl->funcs);
204 }
205 
206 static const char *axp20x_pmx_func_name(struct pinctrl_dev *pctldev,
207 					unsigned int selector)
208 {
209 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
210 
211 	return pctl->funcs[selector].name;
212 }
213 
214 static int axp20x_pmx_func_groups(struct pinctrl_dev *pctldev,
215 				  unsigned int selector,
216 				  const char * const **groups,
217 				  unsigned int *num_groups)
218 {
219 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
220 
221 	*groups = pctl->funcs[selector].groups;
222 	*num_groups = pctl->funcs[selector].ngroups;
223 
224 	return 0;
225 }
226 
227 static int axp20x_pmx_set_mux(struct pinctrl_dev *pctldev,
228 			      unsigned int function, unsigned int group)
229 {
230 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
231 	unsigned int mask;
232 
233 	/* Every pin supports GPIO_OUT and GPIO_IN functions */
234 	if (function <= AXP20X_FUNC_GPIO_IN)
235 		return axp20x_pmx_set(pctldev, group,
236 				      pctl->funcs[function].muxval);
237 
238 	if (function == AXP20X_FUNC_LDO)
239 		mask = pctl->desc->ldo_mask;
240 	else
241 		mask = pctl->desc->adc_mask;
242 
243 	if (!(BIT(group) & mask))
244 		return -EINVAL;
245 
246 	/*
247 	 * We let the regulator framework handle the LDO muxing as muxing bits
248 	 * are basically also regulators on/off bits. It's better not to enforce
249 	 * any state of the regulator when selecting LDO mux so that we don't
250 	 * interfere with the regulator driver.
251 	 */
252 	if (function == AXP20X_FUNC_LDO)
253 		return 0;
254 
255 	return axp20x_pmx_set(pctldev, group, pctl->funcs[function].muxval);
256 }
257 
258 static int axp20x_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
259 					 struct pinctrl_gpio_range *range,
260 					 unsigned int offset, bool input)
261 {
262 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
263 
264 	if (input)
265 		return axp20x_pmx_set(pctldev, offset,
266 				      pctl->funcs[AXP20X_FUNC_GPIO_IN].muxval);
267 
268 	return axp20x_pmx_set(pctldev, offset,
269 			      pctl->funcs[AXP20X_FUNC_GPIO_OUT].muxval);
270 }
271 
272 static const struct pinmux_ops axp20x_pmx_ops = {
273 	.get_functions_count	= axp20x_pmx_func_cnt,
274 	.get_function_name	= axp20x_pmx_func_name,
275 	.get_function_groups	= axp20x_pmx_func_groups,
276 	.set_mux		= axp20x_pmx_set_mux,
277 	.gpio_set_direction	= axp20x_pmx_gpio_set_direction,
278 	.strict			= true,
279 };
280 
281 static int axp20x_groups_cnt(struct pinctrl_dev *pctldev)
282 {
283 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
284 
285 	return pctl->desc->npins;
286 }
287 
288 static int axp20x_group_pins(struct pinctrl_dev *pctldev, unsigned int selector,
289 			     const unsigned int **pins, unsigned int *num_pins)
290 {
291 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
292 
293 	*pins = (unsigned int *)&pctl->desc->pins[selector];
294 	*num_pins = 1;
295 
296 	return 0;
297 }
298 
299 static const char *axp20x_group_name(struct pinctrl_dev *pctldev,
300 				     unsigned int selector)
301 {
302 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
303 
304 	return pctl->desc->pins[selector].name;
305 }
306 
307 static const struct pinctrl_ops axp20x_pctrl_ops = {
308 	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,
309 	.dt_free_map		= pinconf_generic_dt_free_map,
310 	.get_groups_count	= axp20x_groups_cnt,
311 	.get_group_name		= axp20x_group_name,
312 	.get_group_pins		= axp20x_group_pins,
313 };
314 
315 static int axp20x_funcs_groups_from_mask(struct device *dev, unsigned int mask,
316 					  unsigned int mask_len,
317 					  struct axp20x_pinctrl_function *func,
318 					  const struct pinctrl_pin_desc *pins)
319 {
320 	unsigned long int mask_cpy = mask;
321 	const char **group;
322 	unsigned int ngroups = hweight8(mask);
323 	int bit;
324 
325 	func->ngroups = ngroups;
326 	if (func->ngroups > 0) {
327 		func->groups = devm_kcalloc(dev,
328 					    ngroups, sizeof(const char *),
329 					    GFP_KERNEL);
330 		if (!func->groups)
331 			return -ENOMEM;
332 		group = func->groups;
333 		for_each_set_bit(bit, &mask_cpy, mask_len) {
334 			*group = pins[bit].name;
335 			group++;
336 		}
337 	}
338 
339 	return 0;
340 }
341 
342 static int axp20x_build_funcs_groups(struct platform_device *pdev)
343 {
344 	struct axp20x_pctl *pctl = platform_get_drvdata(pdev);
345 	int i, ret, pin, npins = pctl->desc->npins;
346 
347 	pctl->funcs[AXP20X_FUNC_GPIO_OUT].name = "gpio_out";
348 	pctl->funcs[AXP20X_FUNC_GPIO_OUT].muxval = AXP20X_MUX_GPIO_OUT;
349 	pctl->funcs[AXP20X_FUNC_GPIO_IN].name = "gpio_in";
350 	pctl->funcs[AXP20X_FUNC_GPIO_IN].muxval = AXP20X_MUX_GPIO_IN;
351 	pctl->funcs[AXP20X_FUNC_LDO].name = "ldo";
352 	/*
353 	 * Muxval for LDO is useless as we won't use it.
354 	 * See comment in axp20x_pmx_set_mux.
355 	 */
356 	pctl->funcs[AXP20X_FUNC_ADC].name = "adc";
357 	pctl->funcs[AXP20X_FUNC_ADC].muxval = pctl->desc->adc_mux;
358 
359 	/* Every pin supports GPIO_OUT and GPIO_IN functions */
360 	for (i = 0; i <= AXP20X_FUNC_GPIO_IN; i++) {
361 		pctl->funcs[i].ngroups = npins;
362 		pctl->funcs[i].groups = devm_kcalloc(&pdev->dev,
363 						     npins, sizeof(char *),
364 						     GFP_KERNEL);
365 		if (!pctl->funcs[i].groups)
366 			return -ENOMEM;
367 		for (pin = 0; pin < npins; pin++)
368 			pctl->funcs[i].groups[pin] = pctl->desc->pins[pin].name;
369 	}
370 
371 	ret = axp20x_funcs_groups_from_mask(&pdev->dev, pctl->desc->ldo_mask,
372 				      npins, &pctl->funcs[AXP20X_FUNC_LDO],
373 				      pctl->desc->pins);
374 	if (ret)
375 		return ret;
376 
377 	ret = axp20x_funcs_groups_from_mask(&pdev->dev, pctl->desc->adc_mask,
378 				      npins, &pctl->funcs[AXP20X_FUNC_ADC],
379 				      pctl->desc->pins);
380 	if (ret)
381 		return ret;
382 
383 	return 0;
384 }
385 
386 static const struct of_device_id axp20x_pctl_match[] = {
387 	{ .compatible = "x-powers,axp209-gpio", .data = &axp20x_data, },
388 	{ .compatible = "x-powers,axp813-gpio", .data = &axp813_data, },
389 	{ }
390 };
391 MODULE_DEVICE_TABLE(of, axp20x_pctl_match);
392 
393 static int axp20x_pctl_probe(struct platform_device *pdev)
394 {
395 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
396 	struct axp20x_pctl *pctl;
397 	struct device *dev = &pdev->dev;
398 	struct pinctrl_desc *pctrl_desc;
399 	int ret;
400 
401 	if (!of_device_is_available(pdev->dev.of_node))
402 		return -ENODEV;
403 
404 	if (!axp20x) {
405 		dev_err(&pdev->dev, "Parent drvdata not set\n");
406 		return -EINVAL;
407 	}
408 
409 	pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
410 	if (!pctl)
411 		return -ENOMEM;
412 
413 	pctl->chip.base			= -1;
414 	pctl->chip.can_sleep		= true;
415 	pctl->chip.request		= gpiochip_generic_request;
416 	pctl->chip.free			= gpiochip_generic_free;
417 	pctl->chip.parent		= &pdev->dev;
418 	pctl->chip.label		= dev_name(&pdev->dev);
419 	pctl->chip.owner		= THIS_MODULE;
420 	pctl->chip.get			= axp20x_gpio_get;
421 	pctl->chip.get_direction	= axp20x_gpio_get_direction;
422 	pctl->chip.set			= axp20x_gpio_set;
423 	pctl->chip.direction_input	= axp20x_gpio_input;
424 	pctl->chip.direction_output	= axp20x_gpio_output;
425 
426 	pctl->desc = of_device_get_match_data(dev);
427 
428 	pctl->chip.ngpio		= pctl->desc->npins;
429 
430 	pctl->regmap = axp20x->regmap;
431 	pctl->dev = &pdev->dev;
432 
433 	platform_set_drvdata(pdev, pctl);
434 
435 	ret = axp20x_build_funcs_groups(pdev);
436 	if (ret) {
437 		dev_err(&pdev->dev, "failed to build groups\n");
438 		return ret;
439 	}
440 
441 	pctrl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctrl_desc), GFP_KERNEL);
442 	if (!pctrl_desc)
443 		return -ENOMEM;
444 
445 	pctrl_desc->name = dev_name(&pdev->dev);
446 	pctrl_desc->owner = THIS_MODULE;
447 	pctrl_desc->pins = pctl->desc->pins;
448 	pctrl_desc->npins = pctl->desc->npins;
449 	pctrl_desc->pctlops = &axp20x_pctrl_ops;
450 	pctrl_desc->pmxops = &axp20x_pmx_ops;
451 
452 	pctl->pctl_dev = devm_pinctrl_register(&pdev->dev, pctrl_desc, pctl);
453 	if (IS_ERR(pctl->pctl_dev)) {
454 		dev_err(&pdev->dev, "couldn't register pinctrl driver\n");
455 		return PTR_ERR(pctl->pctl_dev);
456 	}
457 
458 	ret = devm_gpiochip_add_data(&pdev->dev, &pctl->chip, pctl);
459 	if (ret) {
460 		dev_err(&pdev->dev, "Failed to register GPIO chip\n");
461 		return ret;
462 	}
463 
464 	ret = gpiochip_add_pin_range(&pctl->chip, dev_name(&pdev->dev),
465 				     pctl->desc->pins->number,
466 				     pctl->desc->pins->number,
467 				     pctl->desc->npins);
468 	if (ret) {
469 		dev_err(&pdev->dev, "failed to add pin range\n");
470 		return ret;
471 	}
472 
473 	dev_info(&pdev->dev, "AXP209 pinctrl and GPIO driver loaded\n");
474 
475 	return 0;
476 }
477 
478 static struct platform_driver axp20x_pctl_driver = {
479 	.probe		= axp20x_pctl_probe,
480 	.driver = {
481 		.name		= "axp20x-gpio",
482 		.of_match_table	= axp20x_pctl_match,
483 	},
484 };
485 
486 module_platform_driver(axp20x_pctl_driver);
487 
488 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
489 MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
490 MODULE_DESCRIPTION("AXP20x PMIC pinctrl and GPIO driver");
491 MODULE_LICENSE("GPL");
492