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 GPIO_LINE_DIRECTION_OUT;
153 
154 	/*
155 	 * The GPIO directions are the three lowest values.
156 	 * 2 is input, 0 and 1 are output
157 	 */
158 	if (val & 2)
159 		return GPIO_LINE_DIRECTION_IN;
160 
161 	return GPIO_LINE_DIRECTION_OUT;
162 }
163 
164 static int axp20x_gpio_output(struct gpio_chip *chip, unsigned int offset,
165 			      int value)
166 {
167 	chip->set(chip, offset, value);
168 
169 	return 0;
170 }
171 
172 static void axp20x_gpio_set(struct gpio_chip *chip, unsigned int offset,
173 			    int value)
174 {
175 	struct axp20x_pctl *pctl = gpiochip_get_data(chip);
176 	int reg;
177 
178 	reg = axp20x_gpio_get_reg(offset);
179 	if (reg < 0)
180 		return;
181 
182 	regmap_update_bits(pctl->regmap, reg,
183 			   AXP20X_GPIO_FUNCTIONS,
184 			   value ? AXP20X_GPIO_FUNCTION_OUT_HIGH :
185 			   AXP20X_GPIO_FUNCTION_OUT_LOW);
186 }
187 
188 static int axp20x_pmx_set(struct pinctrl_dev *pctldev, unsigned int offset,
189 			  u8 config)
190 {
191 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
192 	int reg;
193 
194 	reg = axp20x_gpio_get_reg(offset);
195 	if (reg < 0)
196 		return reg;
197 
198 	return regmap_update_bits(pctl->regmap, reg, AXP20X_GPIO_FUNCTIONS,
199 				  config);
200 }
201 
202 static int axp20x_pmx_func_cnt(struct pinctrl_dev *pctldev)
203 {
204 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
205 
206 	return ARRAY_SIZE(pctl->funcs);
207 }
208 
209 static const char *axp20x_pmx_func_name(struct pinctrl_dev *pctldev,
210 					unsigned int selector)
211 {
212 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
213 
214 	return pctl->funcs[selector].name;
215 }
216 
217 static int axp20x_pmx_func_groups(struct pinctrl_dev *pctldev,
218 				  unsigned int selector,
219 				  const char * const **groups,
220 				  unsigned int *num_groups)
221 {
222 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
223 
224 	*groups = pctl->funcs[selector].groups;
225 	*num_groups = pctl->funcs[selector].ngroups;
226 
227 	return 0;
228 }
229 
230 static int axp20x_pmx_set_mux(struct pinctrl_dev *pctldev,
231 			      unsigned int function, unsigned int group)
232 {
233 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
234 	unsigned int mask;
235 
236 	/* Every pin supports GPIO_OUT and GPIO_IN functions */
237 	if (function <= AXP20X_FUNC_GPIO_IN)
238 		return axp20x_pmx_set(pctldev, group,
239 				      pctl->funcs[function].muxval);
240 
241 	if (function == AXP20X_FUNC_LDO)
242 		mask = pctl->desc->ldo_mask;
243 	else
244 		mask = pctl->desc->adc_mask;
245 
246 	if (!(BIT(group) & mask))
247 		return -EINVAL;
248 
249 	/*
250 	 * We let the regulator framework handle the LDO muxing as muxing bits
251 	 * are basically also regulators on/off bits. It's better not to enforce
252 	 * any state of the regulator when selecting LDO mux so that we don't
253 	 * interfere with the regulator driver.
254 	 */
255 	if (function == AXP20X_FUNC_LDO)
256 		return 0;
257 
258 	return axp20x_pmx_set(pctldev, group, pctl->funcs[function].muxval);
259 }
260 
261 static int axp20x_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
262 					 struct pinctrl_gpio_range *range,
263 					 unsigned int offset, bool input)
264 {
265 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
266 
267 	if (input)
268 		return axp20x_pmx_set(pctldev, offset,
269 				      pctl->funcs[AXP20X_FUNC_GPIO_IN].muxval);
270 
271 	return axp20x_pmx_set(pctldev, offset,
272 			      pctl->funcs[AXP20X_FUNC_GPIO_OUT].muxval);
273 }
274 
275 static const struct pinmux_ops axp20x_pmx_ops = {
276 	.get_functions_count	= axp20x_pmx_func_cnt,
277 	.get_function_name	= axp20x_pmx_func_name,
278 	.get_function_groups	= axp20x_pmx_func_groups,
279 	.set_mux		= axp20x_pmx_set_mux,
280 	.gpio_set_direction	= axp20x_pmx_gpio_set_direction,
281 	.strict			= true,
282 };
283 
284 static int axp20x_groups_cnt(struct pinctrl_dev *pctldev)
285 {
286 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
287 
288 	return pctl->desc->npins;
289 }
290 
291 static int axp20x_group_pins(struct pinctrl_dev *pctldev, unsigned int selector,
292 			     const unsigned int **pins, unsigned int *num_pins)
293 {
294 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
295 
296 	*pins = (unsigned int *)&pctl->desc->pins[selector];
297 	*num_pins = 1;
298 
299 	return 0;
300 }
301 
302 static const char *axp20x_group_name(struct pinctrl_dev *pctldev,
303 				     unsigned int selector)
304 {
305 	struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
306 
307 	return pctl->desc->pins[selector].name;
308 }
309 
310 static const struct pinctrl_ops axp20x_pctrl_ops = {
311 	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,
312 	.dt_free_map		= pinconf_generic_dt_free_map,
313 	.get_groups_count	= axp20x_groups_cnt,
314 	.get_group_name		= axp20x_group_name,
315 	.get_group_pins		= axp20x_group_pins,
316 };
317 
318 static int axp20x_funcs_groups_from_mask(struct device *dev, unsigned int mask,
319 					  unsigned int mask_len,
320 					  struct axp20x_pinctrl_function *func,
321 					  const struct pinctrl_pin_desc *pins)
322 {
323 	unsigned long int mask_cpy = mask;
324 	const char **group;
325 	unsigned int ngroups = hweight8(mask);
326 	int bit;
327 
328 	func->ngroups = ngroups;
329 	if (func->ngroups > 0) {
330 		func->groups = devm_kcalloc(dev,
331 					    ngroups, sizeof(const char *),
332 					    GFP_KERNEL);
333 		if (!func->groups)
334 			return -ENOMEM;
335 		group = func->groups;
336 		for_each_set_bit(bit, &mask_cpy, mask_len) {
337 			*group = pins[bit].name;
338 			group++;
339 		}
340 	}
341 
342 	return 0;
343 }
344 
345 static int axp20x_build_funcs_groups(struct platform_device *pdev)
346 {
347 	struct axp20x_pctl *pctl = platform_get_drvdata(pdev);
348 	int i, ret, pin, npins = pctl->desc->npins;
349 
350 	pctl->funcs[AXP20X_FUNC_GPIO_OUT].name = "gpio_out";
351 	pctl->funcs[AXP20X_FUNC_GPIO_OUT].muxval = AXP20X_MUX_GPIO_OUT;
352 	pctl->funcs[AXP20X_FUNC_GPIO_IN].name = "gpio_in";
353 	pctl->funcs[AXP20X_FUNC_GPIO_IN].muxval = AXP20X_MUX_GPIO_IN;
354 	pctl->funcs[AXP20X_FUNC_LDO].name = "ldo";
355 	/*
356 	 * Muxval for LDO is useless as we won't use it.
357 	 * See comment in axp20x_pmx_set_mux.
358 	 */
359 	pctl->funcs[AXP20X_FUNC_ADC].name = "adc";
360 	pctl->funcs[AXP20X_FUNC_ADC].muxval = pctl->desc->adc_mux;
361 
362 	/* Every pin supports GPIO_OUT and GPIO_IN functions */
363 	for (i = 0; i <= AXP20X_FUNC_GPIO_IN; i++) {
364 		pctl->funcs[i].ngroups = npins;
365 		pctl->funcs[i].groups = devm_kcalloc(&pdev->dev,
366 						     npins, sizeof(char *),
367 						     GFP_KERNEL);
368 		if (!pctl->funcs[i].groups)
369 			return -ENOMEM;
370 		for (pin = 0; pin < npins; pin++)
371 			pctl->funcs[i].groups[pin] = pctl->desc->pins[pin].name;
372 	}
373 
374 	ret = axp20x_funcs_groups_from_mask(&pdev->dev, pctl->desc->ldo_mask,
375 				      npins, &pctl->funcs[AXP20X_FUNC_LDO],
376 				      pctl->desc->pins);
377 	if (ret)
378 		return ret;
379 
380 	ret = axp20x_funcs_groups_from_mask(&pdev->dev, pctl->desc->adc_mask,
381 				      npins, &pctl->funcs[AXP20X_FUNC_ADC],
382 				      pctl->desc->pins);
383 	if (ret)
384 		return ret;
385 
386 	return 0;
387 }
388 
389 static const struct of_device_id axp20x_pctl_match[] = {
390 	{ .compatible = "x-powers,axp209-gpio", .data = &axp20x_data, },
391 	{ .compatible = "x-powers,axp813-gpio", .data = &axp813_data, },
392 	{ }
393 };
394 MODULE_DEVICE_TABLE(of, axp20x_pctl_match);
395 
396 static int axp20x_pctl_probe(struct platform_device *pdev)
397 {
398 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
399 	struct axp20x_pctl *pctl;
400 	struct device *dev = &pdev->dev;
401 	struct pinctrl_desc *pctrl_desc;
402 	int ret;
403 
404 	if (!of_device_is_available(pdev->dev.of_node))
405 		return -ENODEV;
406 
407 	if (!axp20x) {
408 		dev_err(&pdev->dev, "Parent drvdata not set\n");
409 		return -EINVAL;
410 	}
411 
412 	pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
413 	if (!pctl)
414 		return -ENOMEM;
415 
416 	pctl->chip.base			= -1;
417 	pctl->chip.can_sleep		= true;
418 	pctl->chip.request		= gpiochip_generic_request;
419 	pctl->chip.free			= gpiochip_generic_free;
420 	pctl->chip.parent		= &pdev->dev;
421 	pctl->chip.label		= dev_name(&pdev->dev);
422 	pctl->chip.owner		= THIS_MODULE;
423 	pctl->chip.get			= axp20x_gpio_get;
424 	pctl->chip.get_direction	= axp20x_gpio_get_direction;
425 	pctl->chip.set			= axp20x_gpio_set;
426 	pctl->chip.direction_input	= axp20x_gpio_input;
427 	pctl->chip.direction_output	= axp20x_gpio_output;
428 
429 	pctl->desc = of_device_get_match_data(dev);
430 
431 	pctl->chip.ngpio		= pctl->desc->npins;
432 
433 	pctl->regmap = axp20x->regmap;
434 	pctl->dev = &pdev->dev;
435 
436 	platform_set_drvdata(pdev, pctl);
437 
438 	ret = axp20x_build_funcs_groups(pdev);
439 	if (ret) {
440 		dev_err(&pdev->dev, "failed to build groups\n");
441 		return ret;
442 	}
443 
444 	pctrl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctrl_desc), GFP_KERNEL);
445 	if (!pctrl_desc)
446 		return -ENOMEM;
447 
448 	pctrl_desc->name = dev_name(&pdev->dev);
449 	pctrl_desc->owner = THIS_MODULE;
450 	pctrl_desc->pins = pctl->desc->pins;
451 	pctrl_desc->npins = pctl->desc->npins;
452 	pctrl_desc->pctlops = &axp20x_pctrl_ops;
453 	pctrl_desc->pmxops = &axp20x_pmx_ops;
454 
455 	pctl->pctl_dev = devm_pinctrl_register(&pdev->dev, pctrl_desc, pctl);
456 	if (IS_ERR(pctl->pctl_dev)) {
457 		dev_err(&pdev->dev, "couldn't register pinctrl driver\n");
458 		return PTR_ERR(pctl->pctl_dev);
459 	}
460 
461 	ret = devm_gpiochip_add_data(&pdev->dev, &pctl->chip, pctl);
462 	if (ret) {
463 		dev_err(&pdev->dev, "Failed to register GPIO chip\n");
464 		return ret;
465 	}
466 
467 	ret = gpiochip_add_pin_range(&pctl->chip, dev_name(&pdev->dev),
468 				     pctl->desc->pins->number,
469 				     pctl->desc->pins->number,
470 				     pctl->desc->npins);
471 	if (ret) {
472 		dev_err(&pdev->dev, "failed to add pin range\n");
473 		return ret;
474 	}
475 
476 	dev_info(&pdev->dev, "AXP209 pinctrl and GPIO driver loaded\n");
477 
478 	return 0;
479 }
480 
481 static struct platform_driver axp20x_pctl_driver = {
482 	.probe		= axp20x_pctl_probe,
483 	.driver = {
484 		.name		= "axp20x-gpio",
485 		.of_match_table	= axp20x_pctl_match,
486 	},
487 };
488 
489 module_platform_driver(axp20x_pctl_driver);
490 
491 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
492 MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
493 MODULE_DESCRIPTION("AXP20x PMIC pinctrl and GPIO driver");
494 MODULE_LICENSE("GPL");
495