1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Spreadtrum Communications Inc.
4  * Copyright (C) 2018 Linaro Ltd.
5  */
6 
7 #include <linux/gpio/driver.h>
8 #include <linux/interrupt.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/of_device.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 
15 /* EIC registers definition */
16 #define SPRD_PMIC_EIC_DATA		0x0
17 #define SPRD_PMIC_EIC_DMSK		0x4
18 #define SPRD_PMIC_EIC_IEV		0x14
19 #define SPRD_PMIC_EIC_IE		0x18
20 #define SPRD_PMIC_EIC_RIS		0x1c
21 #define SPRD_PMIC_EIC_MIS		0x20
22 #define SPRD_PMIC_EIC_IC		0x24
23 #define SPRD_PMIC_EIC_TRIG		0x28
24 #define SPRD_PMIC_EIC_CTRL0		0x40
25 
26 /*
27  * The PMIC EIC controller only has one bank, and each bank now can contain
28  * 16 EICs.
29  */
30 #define SPRD_PMIC_EIC_PER_BANK_NR	16
31 #define SPRD_PMIC_EIC_NR		SPRD_PMIC_EIC_PER_BANK_NR
32 #define SPRD_PMIC_EIC_DATA_MASK		GENMASK(15, 0)
33 #define SPRD_PMIC_EIC_BIT(x)		((x) & (SPRD_PMIC_EIC_PER_BANK_NR - 1))
34 #define SPRD_PMIC_EIC_DBNC_MASK		GENMASK(11, 0)
35 
36 /*
37  * These registers are modified under the irq bus lock and cached to avoid
38  * unnecessary writes in bus_sync_unlock.
39  */
40 enum {
41 	REG_IEV,
42 	REG_IE,
43 	REG_TRIG,
44 	CACHE_NR_REGS
45 };
46 
47 /**
48  * struct sprd_pmic_eic - PMIC EIC controller
49  * @chip: the gpio_chip structure.
50  * @intc: the irq_chip structure.
51  * @map:  the regmap from the parent device.
52  * @offset: the EIC controller's offset address of the PMIC.
53  * @reg: the array to cache the EIC registers.
54  * @buslock: for bus lock/sync and unlock.
55  * @irq: the interrupt number of the PMIC EIC conteroller.
56  */
57 struct sprd_pmic_eic {
58 	struct gpio_chip chip;
59 	struct irq_chip intc;
60 	struct regmap *map;
61 	u32 offset;
62 	u8 reg[CACHE_NR_REGS];
63 	struct mutex buslock;
64 	int irq;
65 };
66 
67 static void sprd_pmic_eic_update(struct gpio_chip *chip, unsigned int offset,
68 				 u16 reg, unsigned int val)
69 {
70 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
71 	u32 shift = SPRD_PMIC_EIC_BIT(offset);
72 
73 	regmap_update_bits(pmic_eic->map, pmic_eic->offset + reg,
74 			   BIT(shift), val << shift);
75 }
76 
77 static int sprd_pmic_eic_read(struct gpio_chip *chip, unsigned int offset,
78 			      u16 reg)
79 {
80 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
81 	u32 value;
82 	int ret;
83 
84 	ret = regmap_read(pmic_eic->map, pmic_eic->offset + reg, &value);
85 	if (ret)
86 		return ret;
87 
88 	return !!(value & BIT(SPRD_PMIC_EIC_BIT(offset)));
89 }
90 
91 static int sprd_pmic_eic_request(struct gpio_chip *chip, unsigned int offset)
92 {
93 	sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_DMSK, 1);
94 	return 0;
95 }
96 
97 static void sprd_pmic_eic_free(struct gpio_chip *chip, unsigned int offset)
98 {
99 	sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_DMSK, 0);
100 }
101 
102 static int sprd_pmic_eic_get(struct gpio_chip *chip, unsigned int offset)
103 {
104 	return sprd_pmic_eic_read(chip, offset, SPRD_PMIC_EIC_DATA);
105 }
106 
107 static int sprd_pmic_eic_direction_input(struct gpio_chip *chip,
108 					 unsigned int offset)
109 {
110 	/* EICs are always input, nothing need to do here. */
111 	return 0;
112 }
113 
114 static void sprd_pmic_eic_set(struct gpio_chip *chip, unsigned int offset,
115 			      int value)
116 {
117 	/* EICs are always input, nothing need to do here. */
118 }
119 
120 static int sprd_pmic_eic_set_debounce(struct gpio_chip *chip,
121 				      unsigned int offset,
122 				      unsigned int debounce)
123 {
124 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
125 	u32 reg, value;
126 	int ret;
127 
128 	reg = SPRD_PMIC_EIC_CTRL0 + SPRD_PMIC_EIC_BIT(offset) * 0x4;
129 	ret = regmap_read(pmic_eic->map, pmic_eic->offset + reg, &value);
130 	if (ret)
131 		return ret;
132 
133 	value &= ~SPRD_PMIC_EIC_DBNC_MASK;
134 	value |= (debounce / 1000) & SPRD_PMIC_EIC_DBNC_MASK;
135 	return regmap_write(pmic_eic->map, pmic_eic->offset + reg, value);
136 }
137 
138 static int sprd_pmic_eic_set_config(struct gpio_chip *chip, unsigned int offset,
139 				    unsigned long config)
140 {
141 	unsigned long param = pinconf_to_config_param(config);
142 	u32 arg = pinconf_to_config_argument(config);
143 
144 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
145 		return sprd_pmic_eic_set_debounce(chip, offset, arg);
146 
147 	return -ENOTSUPP;
148 }
149 
150 static void sprd_pmic_eic_irq_mask(struct irq_data *data)
151 {
152 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
153 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
154 
155 	pmic_eic->reg[REG_IE] = 0;
156 	pmic_eic->reg[REG_TRIG] = 0;
157 }
158 
159 static void sprd_pmic_eic_irq_unmask(struct irq_data *data)
160 {
161 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
162 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
163 
164 	pmic_eic->reg[REG_IE] = 1;
165 	pmic_eic->reg[REG_TRIG] = 1;
166 }
167 
168 static int sprd_pmic_eic_irq_set_type(struct irq_data *data,
169 				      unsigned int flow_type)
170 {
171 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
172 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
173 
174 	switch (flow_type) {
175 	case IRQ_TYPE_LEVEL_HIGH:
176 		pmic_eic->reg[REG_IEV] = 1;
177 		break;
178 	case IRQ_TYPE_LEVEL_LOW:
179 		pmic_eic->reg[REG_IEV] = 0;
180 		break;
181 	case IRQ_TYPE_EDGE_RISING:
182 	case IRQ_TYPE_EDGE_FALLING:
183 	case IRQ_TYPE_EDGE_BOTH:
184 		/*
185 		 * Will set the trigger level according to current EIC level
186 		 * in irq_bus_sync_unlock() interface, so here nothing to do.
187 		 */
188 		break;
189 	default:
190 		return -ENOTSUPP;
191 	}
192 
193 	return 0;
194 }
195 
196 static void sprd_pmic_eic_bus_lock(struct irq_data *data)
197 {
198 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
199 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
200 
201 	mutex_lock(&pmic_eic->buslock);
202 }
203 
204 static void sprd_pmic_eic_bus_sync_unlock(struct irq_data *data)
205 {
206 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
207 	struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
208 	u32 trigger = irqd_get_trigger_type(data);
209 	u32 offset = irqd_to_hwirq(data);
210 	int state;
211 
212 	/* Set irq type */
213 	if (trigger & IRQ_TYPE_EDGE_BOTH) {
214 		state = sprd_pmic_eic_get(chip, offset);
215 		if (state)
216 			sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 0);
217 		else
218 			sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 1);
219 	} else {
220 		sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV,
221 				     pmic_eic->reg[REG_IEV]);
222 	}
223 
224 	/* Set irq unmask */
225 	sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IE,
226 			     pmic_eic->reg[REG_IE]);
227 	/* Generate trigger start pulse for debounce EIC */
228 	sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_TRIG,
229 			     pmic_eic->reg[REG_TRIG]);
230 
231 	mutex_unlock(&pmic_eic->buslock);
232 }
233 
234 static void sprd_pmic_eic_toggle_trigger(struct gpio_chip *chip,
235 					 unsigned int irq, unsigned int offset)
236 {
237 	u32 trigger = irq_get_trigger_type(irq);
238 	int state, post_state;
239 
240 	if (!(trigger & IRQ_TYPE_EDGE_BOTH))
241 		return;
242 
243 	state = sprd_pmic_eic_get(chip, offset);
244 retry:
245 	if (state)
246 		sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 0);
247 	else
248 		sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 1);
249 
250 	post_state = sprd_pmic_eic_get(chip, offset);
251 	if (state != post_state) {
252 		dev_warn(chip->parent, "PMIC EIC level was changed.\n");
253 		state = post_state;
254 		goto retry;
255 	}
256 
257 	/* Set irq unmask */
258 	sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IE, 1);
259 	/* Generate trigger start pulse for debounce EIC */
260 	sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_TRIG, 1);
261 }
262 
263 static irqreturn_t sprd_pmic_eic_irq_handler(int irq, void *data)
264 {
265 	struct sprd_pmic_eic *pmic_eic = data;
266 	struct gpio_chip *chip = &pmic_eic->chip;
267 	unsigned long status;
268 	u32 n, girq, val;
269 	int ret;
270 
271 	ret = regmap_read(pmic_eic->map, pmic_eic->offset + SPRD_PMIC_EIC_MIS,
272 			  &val);
273 	if (ret)
274 		return IRQ_RETVAL(ret);
275 
276 	status = val & SPRD_PMIC_EIC_DATA_MASK;
277 
278 	for_each_set_bit(n, &status, chip->ngpio) {
279 		/* Clear the interrupt */
280 		sprd_pmic_eic_update(chip, n, SPRD_PMIC_EIC_IC, 1);
281 
282 		girq = irq_find_mapping(chip->irq.domain, n);
283 		handle_nested_irq(girq);
284 
285 		/*
286 		 * The PMIC EIC can only support level trigger, so we can
287 		 * toggle the level trigger to emulate the edge trigger.
288 		 */
289 		sprd_pmic_eic_toggle_trigger(chip, girq, n);
290 	}
291 
292 	return IRQ_HANDLED;
293 }
294 
295 static int sprd_pmic_eic_probe(struct platform_device *pdev)
296 {
297 	struct gpio_irq_chip *irq;
298 	struct sprd_pmic_eic *pmic_eic;
299 	int ret;
300 
301 	pmic_eic = devm_kzalloc(&pdev->dev, sizeof(*pmic_eic), GFP_KERNEL);
302 	if (!pmic_eic)
303 		return -ENOMEM;
304 
305 	mutex_init(&pmic_eic->buslock);
306 
307 	pmic_eic->irq = platform_get_irq(pdev, 0);
308 	if (pmic_eic->irq < 0)
309 		return pmic_eic->irq;
310 
311 	pmic_eic->map = dev_get_regmap(pdev->dev.parent, NULL);
312 	if (!pmic_eic->map)
313 		return -ENODEV;
314 
315 	ret = of_property_read_u32(pdev->dev.of_node, "reg", &pmic_eic->offset);
316 	if (ret) {
317 		dev_err(&pdev->dev, "Failed to get PMIC EIC base address.\n");
318 		return ret;
319 	}
320 
321 	ret = devm_request_threaded_irq(&pdev->dev, pmic_eic->irq, NULL,
322 					sprd_pmic_eic_irq_handler,
323 					IRQF_ONESHOT | IRQF_NO_SUSPEND,
324 					dev_name(&pdev->dev), pmic_eic);
325 	if (ret) {
326 		dev_err(&pdev->dev, "Failed to request PMIC EIC IRQ.\n");
327 		return ret;
328 	}
329 
330 	pmic_eic->chip.label = dev_name(&pdev->dev);
331 	pmic_eic->chip.ngpio = SPRD_PMIC_EIC_NR;
332 	pmic_eic->chip.base = -1;
333 	pmic_eic->chip.parent = &pdev->dev;
334 	pmic_eic->chip.direction_input = sprd_pmic_eic_direction_input;
335 	pmic_eic->chip.request = sprd_pmic_eic_request;
336 	pmic_eic->chip.free = sprd_pmic_eic_free;
337 	pmic_eic->chip.set_config = sprd_pmic_eic_set_config;
338 	pmic_eic->chip.set = sprd_pmic_eic_set;
339 	pmic_eic->chip.get = sprd_pmic_eic_get;
340 
341 	pmic_eic->intc.name = dev_name(&pdev->dev);
342 	pmic_eic->intc.irq_mask = sprd_pmic_eic_irq_mask;
343 	pmic_eic->intc.irq_unmask = sprd_pmic_eic_irq_unmask;
344 	pmic_eic->intc.irq_set_type = sprd_pmic_eic_irq_set_type;
345 	pmic_eic->intc.irq_bus_lock = sprd_pmic_eic_bus_lock;
346 	pmic_eic->intc.irq_bus_sync_unlock = sprd_pmic_eic_bus_sync_unlock;
347 	pmic_eic->intc.flags = IRQCHIP_SKIP_SET_WAKE;
348 
349 	irq = &pmic_eic->chip.irq;
350 	irq->chip = &pmic_eic->intc;
351 	irq->threaded = true;
352 
353 	ret = devm_gpiochip_add_data(&pdev->dev, &pmic_eic->chip, pmic_eic);
354 	if (ret < 0) {
355 		dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
356 		return ret;
357 	}
358 
359 	platform_set_drvdata(pdev, pmic_eic);
360 	return 0;
361 }
362 
363 static const struct of_device_id sprd_pmic_eic_of_match[] = {
364 	{ .compatible = "sprd,sc2731-eic", },
365 	{ /* end of list */ }
366 };
367 MODULE_DEVICE_TABLE(of, sprd_pmic_eic_of_match);
368 
369 static struct platform_driver sprd_pmic_eic_driver = {
370 	.probe = sprd_pmic_eic_probe,
371 	.driver = {
372 		.name = "sprd-pmic-eic",
373 		.of_match_table	= sprd_pmic_eic_of_match,
374 	},
375 };
376 
377 module_platform_driver(sprd_pmic_eic_driver);
378 
379 MODULE_DESCRIPTION("Spreadtrum PMIC EIC driver");
380 MODULE_LICENSE("GPL v2");
381