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