1 /*
2  * gpio-crystalcove.c - Intel Crystal Cove GPIO Driver
3  *
4  * Copyright (C) 2012, 2014 Intel Corporation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version
8  * 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * Author: Yang, Bin <bin.yang@intel.com>
16  */
17 
18 #include <linux/interrupt.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/gpio.h>
22 #include <linux/seq_file.h>
23 #include <linux/bitops.h>
24 #include <linux/regmap.h>
25 #include <linux/mfd/intel_soc_pmic.h>
26 
27 #define CRYSTALCOVE_GPIO_NUM	16
28 #define CRYSTALCOVE_VGPIO_NUM	95
29 
30 #define UPDATE_IRQ_TYPE		BIT(0)
31 #define UPDATE_IRQ_MASK		BIT(1)
32 
33 #define GPIO0IRQ		0x0b
34 #define GPIO1IRQ		0x0c
35 #define MGPIO0IRQS0		0x19
36 #define MGPIO1IRQS0		0x1a
37 #define MGPIO0IRQSX		0x1b
38 #define MGPIO1IRQSX		0x1c
39 #define GPIO0P0CTLO		0x2b
40 #define GPIO0P0CTLI		0x33
41 #define GPIO1P0CTLO		0x3b
42 #define GPIO1P0CTLI		0x43
43 #define GPIOPANELCTL		0x52
44 
45 #define CTLI_INTCNT_DIS		(0)
46 #define CTLI_INTCNT_NE		(1 << 1)
47 #define CTLI_INTCNT_PE		(2 << 1)
48 #define CTLI_INTCNT_BE		(3 << 1)
49 
50 #define CTLO_DIR_IN		(0)
51 #define CTLO_DIR_OUT		(1 << 5)
52 
53 #define CTLO_DRV_CMOS		(0)
54 #define CTLO_DRV_OD		(1 << 4)
55 
56 #define CTLO_DRV_REN		(1 << 3)
57 
58 #define CTLO_RVAL_2KDW		(0)
59 #define CTLO_RVAL_2KUP		(1 << 1)
60 #define CTLO_RVAL_50KDW		(2 << 1)
61 #define CTLO_RVAL_50KUP		(3 << 1)
62 
63 #define CTLO_INPUT_SET	(CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
64 #define CTLO_OUTPUT_SET	(CTLO_DIR_OUT | CTLO_INPUT_SET)
65 
66 enum ctrl_register {
67 	CTRL_IN,
68 	CTRL_OUT,
69 };
70 
71 /**
72  * struct crystalcove_gpio - Crystal Cove GPIO controller
73  * @buslock: for bus lock/sync and unlock.
74  * @chip: the abstract gpio_chip structure.
75  * @regmap: the regmap from the parent device.
76  * @update: pending IRQ setting update, to be written to the chip upon unlock.
77  * @intcnt_value: the Interrupt Detect value to be written.
78  * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
79  */
80 struct crystalcove_gpio {
81 	struct mutex buslock; /* irq_bus_lock */
82 	struct gpio_chip chip;
83 	struct regmap *regmap;
84 	int update;
85 	int intcnt_value;
86 	bool set_irq_mask;
87 };
88 
89 static inline int to_reg(int gpio, enum ctrl_register reg_type)
90 {
91 	int reg;
92 
93 	if (gpio == 94)
94 		return GPIOPANELCTL;
95 
96 	if (reg_type == CTRL_IN) {
97 		if (gpio < 8)
98 			reg = GPIO0P0CTLI;
99 		else
100 			reg = GPIO1P0CTLI;
101 	} else {
102 		if (gpio < 8)
103 			reg = GPIO0P0CTLO;
104 		else
105 			reg = GPIO1P0CTLO;
106 	}
107 
108 	return reg + gpio % 8;
109 }
110 
111 static void crystalcove_update_irq_mask(struct crystalcove_gpio *cg,
112 					int gpio)
113 {
114 	u8 mirqs0 = gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0;
115 	int mask = BIT(gpio % 8);
116 
117 	if (cg->set_irq_mask)
118 		regmap_update_bits(cg->regmap, mirqs0, mask, mask);
119 	else
120 		regmap_update_bits(cg->regmap, mirqs0, mask, 0);
121 }
122 
123 static void crystalcove_update_irq_ctrl(struct crystalcove_gpio *cg, int gpio)
124 {
125 	int reg = to_reg(gpio, CTRL_IN);
126 
127 	regmap_update_bits(cg->regmap, reg, CTLI_INTCNT_BE, cg->intcnt_value);
128 }
129 
130 static int crystalcove_gpio_dir_in(struct gpio_chip *chip, unsigned gpio)
131 {
132 	struct crystalcove_gpio *cg = gpiochip_get_data(chip);
133 
134 	if (gpio > CRYSTALCOVE_VGPIO_NUM)
135 		return 0;
136 
137 	return regmap_write(cg->regmap, to_reg(gpio, CTRL_OUT),
138 			    CTLO_INPUT_SET);
139 }
140 
141 static int crystalcove_gpio_dir_out(struct gpio_chip *chip, unsigned gpio,
142 				    int value)
143 {
144 	struct crystalcove_gpio *cg = gpiochip_get_data(chip);
145 
146 	if (gpio > CRYSTALCOVE_VGPIO_NUM)
147 		return 0;
148 
149 	return regmap_write(cg->regmap, to_reg(gpio, CTRL_OUT),
150 			    CTLO_OUTPUT_SET | value);
151 }
152 
153 static int crystalcove_gpio_get(struct gpio_chip *chip, unsigned gpio)
154 {
155 	struct crystalcove_gpio *cg = gpiochip_get_data(chip);
156 	int ret;
157 	unsigned int val;
158 
159 	if (gpio > CRYSTALCOVE_VGPIO_NUM)
160 		return 0;
161 
162 	ret = regmap_read(cg->regmap, to_reg(gpio, CTRL_IN), &val);
163 	if (ret)
164 		return ret;
165 
166 	return val & 0x1;
167 }
168 
169 static void crystalcove_gpio_set(struct gpio_chip *chip,
170 				 unsigned gpio, int value)
171 {
172 	struct crystalcove_gpio *cg = gpiochip_get_data(chip);
173 
174 	if (gpio > CRYSTALCOVE_VGPIO_NUM)
175 		return;
176 
177 	if (value)
178 		regmap_update_bits(cg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
179 	else
180 		regmap_update_bits(cg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
181 }
182 
183 static int crystalcove_irq_type(struct irq_data *data, unsigned type)
184 {
185 	struct crystalcove_gpio *cg =
186 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
187 
188 	switch (type) {
189 	case IRQ_TYPE_NONE:
190 		cg->intcnt_value = CTLI_INTCNT_DIS;
191 		break;
192 	case IRQ_TYPE_EDGE_BOTH:
193 		cg->intcnt_value = CTLI_INTCNT_BE;
194 		break;
195 	case IRQ_TYPE_EDGE_RISING:
196 		cg->intcnt_value = CTLI_INTCNT_PE;
197 		break;
198 	case IRQ_TYPE_EDGE_FALLING:
199 		cg->intcnt_value = CTLI_INTCNT_NE;
200 		break;
201 	default:
202 		return -EINVAL;
203 	}
204 
205 	cg->update |= UPDATE_IRQ_TYPE;
206 
207 	return 0;
208 }
209 
210 static void crystalcove_bus_lock(struct irq_data *data)
211 {
212 	struct crystalcove_gpio *cg =
213 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
214 
215 	mutex_lock(&cg->buslock);
216 }
217 
218 static void crystalcove_bus_sync_unlock(struct irq_data *data)
219 {
220 	struct crystalcove_gpio *cg =
221 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
222 	int gpio = data->hwirq;
223 
224 	if (cg->update & UPDATE_IRQ_TYPE)
225 		crystalcove_update_irq_ctrl(cg, gpio);
226 	if (cg->update & UPDATE_IRQ_MASK)
227 		crystalcove_update_irq_mask(cg, gpio);
228 	cg->update = 0;
229 
230 	mutex_unlock(&cg->buslock);
231 }
232 
233 static void crystalcove_irq_unmask(struct irq_data *data)
234 {
235 	struct crystalcove_gpio *cg =
236 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
237 
238 	cg->set_irq_mask = false;
239 	cg->update |= UPDATE_IRQ_MASK;
240 }
241 
242 static void crystalcove_irq_mask(struct irq_data *data)
243 {
244 	struct crystalcove_gpio *cg =
245 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
246 
247 	cg->set_irq_mask = true;
248 	cg->update |= UPDATE_IRQ_MASK;
249 }
250 
251 static struct irq_chip crystalcove_irqchip = {
252 	.name			= "Crystal Cove",
253 	.irq_mask		= crystalcove_irq_mask,
254 	.irq_unmask		= crystalcove_irq_unmask,
255 	.irq_set_type		= crystalcove_irq_type,
256 	.irq_bus_lock		= crystalcove_bus_lock,
257 	.irq_bus_sync_unlock	= crystalcove_bus_sync_unlock,
258 	.flags			= IRQCHIP_SKIP_SET_WAKE,
259 };
260 
261 static irqreturn_t crystalcove_gpio_irq_handler(int irq, void *data)
262 {
263 	struct crystalcove_gpio *cg = data;
264 	unsigned int p0, p1;
265 	int pending;
266 	int gpio;
267 	unsigned int virq;
268 
269 	if (regmap_read(cg->regmap, GPIO0IRQ, &p0) ||
270 	    regmap_read(cg->regmap, GPIO1IRQ, &p1))
271 		return IRQ_NONE;
272 
273 	regmap_write(cg->regmap, GPIO0IRQ, p0);
274 	regmap_write(cg->regmap, GPIO1IRQ, p1);
275 
276 	pending = p0 | p1 << 8;
277 
278 	for (gpio = 0; gpio < CRYSTALCOVE_GPIO_NUM; gpio++) {
279 		if (pending & BIT(gpio)) {
280 			virq = irq_find_mapping(cg->chip.irqdomain, gpio);
281 			handle_nested_irq(virq);
282 		}
283 	}
284 
285 	return IRQ_HANDLED;
286 }
287 
288 static void crystalcove_gpio_dbg_show(struct seq_file *s,
289 				      struct gpio_chip *chip)
290 {
291 	struct crystalcove_gpio *cg = gpiochip_get_data(chip);
292 	int gpio, offset;
293 	unsigned int ctlo, ctli, mirqs0, mirqsx, irq;
294 
295 	for (gpio = 0; gpio < CRYSTALCOVE_GPIO_NUM; gpio++) {
296 		regmap_read(cg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
297 		regmap_read(cg->regmap, to_reg(gpio, CTRL_IN), &ctli);
298 		regmap_read(cg->regmap, gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0,
299 			    &mirqs0);
300 		regmap_read(cg->regmap, gpio < 8 ? MGPIO0IRQSX : MGPIO1IRQSX,
301 			    &mirqsx);
302 		regmap_read(cg->regmap, gpio < 8 ? GPIO0IRQ : GPIO1IRQ,
303 			    &irq);
304 
305 		offset = gpio % 8;
306 		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s %s\n",
307 			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
308 			   ctli & 0x1 ? "hi" : "lo",
309 			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
310 			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
311 			   ctlo,
312 			   mirqs0 & BIT(offset) ? "s0 mask  " : "s0 unmask",
313 			   mirqsx & BIT(offset) ? "sx mask  " : "sx unmask",
314 			   irq & BIT(offset) ? "pending" : "       ");
315 	}
316 }
317 
318 static int crystalcove_gpio_probe(struct platform_device *pdev)
319 {
320 	int irq = platform_get_irq(pdev, 0);
321 	struct crystalcove_gpio *cg;
322 	int retval;
323 	struct device *dev = pdev->dev.parent;
324 	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
325 
326 	if (irq < 0)
327 		return irq;
328 
329 	cg = devm_kzalloc(&pdev->dev, sizeof(*cg), GFP_KERNEL);
330 	if (!cg)
331 		return -ENOMEM;
332 
333 	platform_set_drvdata(pdev, cg);
334 
335 	mutex_init(&cg->buslock);
336 	cg->chip.label = KBUILD_MODNAME;
337 	cg->chip.direction_input = crystalcove_gpio_dir_in;
338 	cg->chip.direction_output = crystalcove_gpio_dir_out;
339 	cg->chip.get = crystalcove_gpio_get;
340 	cg->chip.set = crystalcove_gpio_set;
341 	cg->chip.base = -1;
342 	cg->chip.ngpio = CRYSTALCOVE_VGPIO_NUM;
343 	cg->chip.can_sleep = true;
344 	cg->chip.parent = dev;
345 	cg->chip.dbg_show = crystalcove_gpio_dbg_show;
346 	cg->regmap = pmic->regmap;
347 
348 	retval = devm_gpiochip_add_data(&pdev->dev, &cg->chip, cg);
349 	if (retval) {
350 		dev_warn(&pdev->dev, "add gpio chip error: %d\n", retval);
351 		return retval;
352 	}
353 
354 	gpiochip_irqchip_add(&cg->chip, &crystalcove_irqchip, 0,
355 			     handle_simple_irq, IRQ_TYPE_NONE);
356 
357 	retval = request_threaded_irq(irq, NULL, crystalcove_gpio_irq_handler,
358 				      IRQF_ONESHOT, KBUILD_MODNAME, cg);
359 
360 	if (retval) {
361 		dev_warn(&pdev->dev, "request irq failed: %d\n", retval);
362 		return retval;
363 	}
364 
365 	return 0;
366 }
367 
368 static int crystalcove_gpio_remove(struct platform_device *pdev)
369 {
370 	struct crystalcove_gpio *cg = platform_get_drvdata(pdev);
371 	int irq = platform_get_irq(pdev, 0);
372 
373 	if (irq >= 0)
374 		free_irq(irq, cg);
375 	return 0;
376 }
377 
378 static struct platform_driver crystalcove_gpio_driver = {
379 	.probe = crystalcove_gpio_probe,
380 	.remove = crystalcove_gpio_remove,
381 	.driver = {
382 		.name = "crystal_cove_gpio",
383 	},
384 };
385 
386 module_platform_driver(crystalcove_gpio_driver);
387 
388 MODULE_AUTHOR("Yang, Bin <bin.yang@intel.com>");
389 MODULE_DESCRIPTION("Intel Crystal Cove GPIO Driver");
390 MODULE_LICENSE("GPL v2");
391