1 /*
2  * Intel Merrifield SoC GPIO driver
3  *
4  * Copyright (c) 2016 Intel Corporation.
5  * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/bitops.h>
13 #include <linux/gpio/driver.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 #include <linux/pinctrl/consumer.h>
20 
21 #define GCCR		0x000	/* controller configuration */
22 #define GPLR		0x004	/* pin level r/o */
23 #define GPDR		0x01c	/* pin direction */
24 #define GPSR		0x034	/* pin set w/o */
25 #define GPCR		0x04c	/* pin clear w/o */
26 #define GRER		0x064	/* rising edge detect */
27 #define GFER		0x07c	/* falling edge detect */
28 #define GFBR		0x094	/* glitch filter bypass */
29 #define GIMR		0x0ac	/* interrupt mask */
30 #define GISR		0x0c4	/* interrupt source */
31 #define GITR		0x300	/* input type */
32 #define GLPR		0x318	/* level input polarity */
33 #define GWMR		0x400	/* wake mask */
34 #define GWSR		0x418	/* wake source */
35 #define GSIR		0xc00	/* secure input */
36 
37 /* Intel Merrifield has 192 GPIO pins */
38 #define MRFLD_NGPIO	192
39 
40 struct mrfld_gpio_pinrange {
41 	unsigned int gpio_base;
42 	unsigned int pin_base;
43 	unsigned int npins;
44 };
45 
46 #define GPIO_PINRANGE(gstart, gend, pstart)		\
47 	{						\
48 		.gpio_base = (gstart),			\
49 		.pin_base = (pstart),			\
50 		.npins = (gend) - (gstart) + 1,		\
51 	}
52 
53 struct mrfld_gpio {
54 	struct gpio_chip	chip;
55 	void __iomem		*reg_base;
56 	raw_spinlock_t		lock;
57 	struct device		*dev;
58 };
59 
60 static const struct mrfld_gpio_pinrange mrfld_gpio_ranges[] = {
61 	GPIO_PINRANGE(0, 11, 146),
62 	GPIO_PINRANGE(12, 13, 144),
63 	GPIO_PINRANGE(14, 15, 35),
64 	GPIO_PINRANGE(16, 16, 164),
65 	GPIO_PINRANGE(17, 18, 105),
66 	GPIO_PINRANGE(19, 22, 101),
67 	GPIO_PINRANGE(23, 30, 107),
68 	GPIO_PINRANGE(32, 43, 67),
69 	GPIO_PINRANGE(44, 63, 195),
70 	GPIO_PINRANGE(64, 67, 140),
71 	GPIO_PINRANGE(68, 69, 165),
72 	GPIO_PINRANGE(70, 71, 65),
73 	GPIO_PINRANGE(72, 76, 228),
74 	GPIO_PINRANGE(77, 86, 37),
75 	GPIO_PINRANGE(87, 87, 48),
76 	GPIO_PINRANGE(88, 88, 47),
77 	GPIO_PINRANGE(89, 96, 49),
78 	GPIO_PINRANGE(97, 97, 34),
79 	GPIO_PINRANGE(102, 119, 83),
80 	GPIO_PINRANGE(120, 123, 79),
81 	GPIO_PINRANGE(124, 135, 115),
82 	GPIO_PINRANGE(137, 142, 158),
83 	GPIO_PINRANGE(154, 163, 24),
84 	GPIO_PINRANGE(164, 176, 215),
85 	GPIO_PINRANGE(177, 189, 127),
86 	GPIO_PINRANGE(190, 191, 178),
87 };
88 
89 static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned int offset,
90 			      unsigned int reg_type_offset)
91 {
92 	struct mrfld_gpio *priv = gpiochip_get_data(chip);
93 	u8 reg = offset / 32;
94 
95 	return priv->reg_base + reg_type_offset + reg * 4;
96 }
97 
98 static int mrfld_gpio_get(struct gpio_chip *chip, unsigned int offset)
99 {
100 	void __iomem *gplr = gpio_reg(chip, offset, GPLR);
101 
102 	return !!(readl(gplr) & BIT(offset % 32));
103 }
104 
105 static void mrfld_gpio_set(struct gpio_chip *chip, unsigned int offset,
106 			   int value)
107 {
108 	struct mrfld_gpio *priv = gpiochip_get_data(chip);
109 	void __iomem *gpsr, *gpcr;
110 	unsigned long flags;
111 
112 	raw_spin_lock_irqsave(&priv->lock, flags);
113 
114 	if (value) {
115 		gpsr = gpio_reg(chip, offset, GPSR);
116 		writel(BIT(offset % 32), gpsr);
117 	} else {
118 		gpcr = gpio_reg(chip, offset, GPCR);
119 		writel(BIT(offset % 32), gpcr);
120 	}
121 
122 	raw_spin_unlock_irqrestore(&priv->lock, flags);
123 }
124 
125 static int mrfld_gpio_direction_input(struct gpio_chip *chip,
126 				      unsigned int offset)
127 {
128 	struct mrfld_gpio *priv = gpiochip_get_data(chip);
129 	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
130 	unsigned long flags;
131 	u32 value;
132 
133 	raw_spin_lock_irqsave(&priv->lock, flags);
134 
135 	value = readl(gpdr);
136 	value &= ~BIT(offset % 32);
137 	writel(value, gpdr);
138 
139 	raw_spin_unlock_irqrestore(&priv->lock, flags);
140 
141 	return 0;
142 }
143 
144 static int mrfld_gpio_direction_output(struct gpio_chip *chip,
145 				       unsigned int offset, int value)
146 {
147 	struct mrfld_gpio *priv = gpiochip_get_data(chip);
148 	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
149 	unsigned long flags;
150 
151 	mrfld_gpio_set(chip, offset, value);
152 
153 	raw_spin_lock_irqsave(&priv->lock, flags);
154 
155 	value = readl(gpdr);
156 	value |= BIT(offset % 32);
157 	writel(value, gpdr);
158 
159 	raw_spin_unlock_irqrestore(&priv->lock, flags);
160 
161 	return 0;
162 }
163 
164 static int mrfld_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
165 {
166 	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
167 
168 	return !(readl(gpdr) & BIT(offset % 32));
169 }
170 
171 static int mrfld_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,
172 				   unsigned int debounce)
173 {
174 	struct mrfld_gpio *priv = gpiochip_get_data(chip);
175 	void __iomem *gfbr = gpio_reg(chip, offset, GFBR);
176 	unsigned long flags;
177 	u32 value;
178 
179 	raw_spin_lock_irqsave(&priv->lock, flags);
180 
181 	if (debounce)
182 		value = readl(gfbr) & ~BIT(offset % 32);
183 	else
184 		value = readl(gfbr) | BIT(offset % 32);
185 	writel(value, gfbr);
186 
187 	raw_spin_unlock_irqrestore(&priv->lock, flags);
188 
189 	return 0;
190 }
191 
192 static int mrfld_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
193 				 unsigned long config)
194 {
195 	u32 debounce;
196 
197 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
198 		return -ENOTSUPP;
199 
200 	debounce = pinconf_to_config_argument(config);
201 	return mrfld_gpio_set_debounce(chip, offset, debounce);
202 }
203 
204 static void mrfld_irq_ack(struct irq_data *d)
205 {
206 	struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);
207 	u32 gpio = irqd_to_hwirq(d);
208 	void __iomem *gisr = gpio_reg(&priv->chip, gpio, GISR);
209 	unsigned long flags;
210 
211 	raw_spin_lock_irqsave(&priv->lock, flags);
212 
213 	writel(BIT(gpio % 32), gisr);
214 
215 	raw_spin_unlock_irqrestore(&priv->lock, flags);
216 }
217 
218 static void mrfld_irq_unmask_mask(struct irq_data *d, bool unmask)
219 {
220 	struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);
221 	u32 gpio = irqd_to_hwirq(d);
222 	void __iomem *gimr = gpio_reg(&priv->chip, gpio, GIMR);
223 	unsigned long flags;
224 	u32 value;
225 
226 	raw_spin_lock_irqsave(&priv->lock, flags);
227 
228 	if (unmask)
229 		value = readl(gimr) | BIT(gpio % 32);
230 	else
231 		value = readl(gimr) & ~BIT(gpio % 32);
232 	writel(value, gimr);
233 
234 	raw_spin_unlock_irqrestore(&priv->lock, flags);
235 }
236 
237 static void mrfld_irq_mask(struct irq_data *d)
238 {
239 	mrfld_irq_unmask_mask(d, false);
240 }
241 
242 static void mrfld_irq_unmask(struct irq_data *d)
243 {
244 	mrfld_irq_unmask_mask(d, true);
245 }
246 
247 static int mrfld_irq_set_type(struct irq_data *d, unsigned int type)
248 {
249 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
250 	struct mrfld_gpio *priv = gpiochip_get_data(gc);
251 	u32 gpio = irqd_to_hwirq(d);
252 	void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
253 	void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
254 	void __iomem *gitr = gpio_reg(&priv->chip, gpio, GITR);
255 	void __iomem *glpr = gpio_reg(&priv->chip, gpio, GLPR);
256 	unsigned long flags;
257 	u32 value;
258 
259 	raw_spin_lock_irqsave(&priv->lock, flags);
260 
261 	if (type & IRQ_TYPE_EDGE_RISING)
262 		value = readl(grer) | BIT(gpio % 32);
263 	else
264 		value = readl(grer) & ~BIT(gpio % 32);
265 	writel(value, grer);
266 
267 	if (type & IRQ_TYPE_EDGE_FALLING)
268 		value = readl(gfer) | BIT(gpio % 32);
269 	else
270 		value = readl(gfer) & ~BIT(gpio % 32);
271 	writel(value, gfer);
272 
273 	/*
274 	 * To prevent glitches from triggering an unintended level interrupt,
275 	 * configure GLPR register first and then configure GITR.
276 	 */
277 	if (type & IRQ_TYPE_LEVEL_LOW)
278 		value = readl(glpr) | BIT(gpio % 32);
279 	else
280 		value = readl(glpr) & ~BIT(gpio % 32);
281 	writel(value, glpr);
282 
283 	if (type & IRQ_TYPE_LEVEL_MASK) {
284 		value = readl(gitr) | BIT(gpio % 32);
285 		writel(value, gitr);
286 
287 		irq_set_handler_locked(d, handle_level_irq);
288 	} else if (type & IRQ_TYPE_EDGE_BOTH) {
289 		value = readl(gitr) & ~BIT(gpio % 32);
290 		writel(value, gitr);
291 
292 		irq_set_handler_locked(d, handle_edge_irq);
293 	}
294 
295 	raw_spin_unlock_irqrestore(&priv->lock, flags);
296 
297 	return 0;
298 }
299 
300 static int mrfld_irq_set_wake(struct irq_data *d, unsigned int on)
301 {
302 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
303 	struct mrfld_gpio *priv = gpiochip_get_data(gc);
304 	u32 gpio = irqd_to_hwirq(d);
305 	void __iomem *gwmr = gpio_reg(&priv->chip, gpio, GWMR);
306 	void __iomem *gwsr = gpio_reg(&priv->chip, gpio, GWSR);
307 	unsigned long flags;
308 	u32 value;
309 
310 	raw_spin_lock_irqsave(&priv->lock, flags);
311 
312 	/* Clear the existing wake status */
313 	writel(BIT(gpio % 32), gwsr);
314 
315 	if (on)
316 		value = readl(gwmr) | BIT(gpio % 32);
317 	else
318 		value = readl(gwmr) & ~BIT(gpio % 32);
319 	writel(value, gwmr);
320 
321 	raw_spin_unlock_irqrestore(&priv->lock, flags);
322 
323 	dev_dbg(priv->dev, "%sable wake for gpio %u\n", on ? "en" : "dis", gpio);
324 	return 0;
325 }
326 
327 static struct irq_chip mrfld_irqchip = {
328 	.name		= "gpio-merrifield",
329 	.irq_ack	= mrfld_irq_ack,
330 	.irq_mask	= mrfld_irq_mask,
331 	.irq_unmask	= mrfld_irq_unmask,
332 	.irq_set_type	= mrfld_irq_set_type,
333 	.irq_set_wake	= mrfld_irq_set_wake,
334 };
335 
336 static void mrfld_irq_handler(struct irq_desc *desc)
337 {
338 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
339 	struct mrfld_gpio *priv = gpiochip_get_data(gc);
340 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
341 	unsigned long base, gpio;
342 
343 	chained_irq_enter(irqchip, desc);
344 
345 	/* Check GPIO controller to check which pin triggered the interrupt */
346 	for (base = 0; base < priv->chip.ngpio; base += 32) {
347 		void __iomem *gisr = gpio_reg(&priv->chip, base, GISR);
348 		void __iomem *gimr = gpio_reg(&priv->chip, base, GIMR);
349 		unsigned long pending, enabled;
350 
351 		pending = readl(gisr);
352 		enabled = readl(gimr);
353 
354 		/* Only interrupts that are enabled */
355 		pending &= enabled;
356 
357 		for_each_set_bit(gpio, &pending, 32) {
358 			unsigned int irq;
359 
360 			irq = irq_find_mapping(gc->irqdomain, base + gpio);
361 			generic_handle_irq(irq);
362 		}
363 	}
364 
365 	chained_irq_exit(irqchip, desc);
366 }
367 
368 static void mrfld_irq_init_hw(struct mrfld_gpio *priv)
369 {
370 	void __iomem *reg;
371 	unsigned int base;
372 
373 	for (base = 0; base < priv->chip.ngpio; base += 32) {
374 		/* Clear the rising-edge detect register */
375 		reg = gpio_reg(&priv->chip, base, GRER);
376 		writel(0, reg);
377 		/* Clear the falling-edge detect register */
378 		reg = gpio_reg(&priv->chip, base, GFER);
379 		writel(0, reg);
380 	}
381 }
382 
383 static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id)
384 {
385 	const struct mrfld_gpio_pinrange *range;
386 	struct mrfld_gpio *priv;
387 	u32 gpio_base, irq_base;
388 	void __iomem *base;
389 	unsigned int i;
390 	int retval;
391 
392 	retval = pcim_enable_device(pdev);
393 	if (retval)
394 		return retval;
395 
396 	retval = pcim_iomap_regions(pdev, BIT(1) | BIT(0), pci_name(pdev));
397 	if (retval) {
398 		dev_err(&pdev->dev, "I/O memory mapping error\n");
399 		return retval;
400 	}
401 
402 	base = pcim_iomap_table(pdev)[1];
403 
404 	irq_base = readl(base);
405 	gpio_base = readl(sizeof(u32) + base);
406 
407 	/* Release the IO mapping, since we already get the info from BAR1 */
408 	pcim_iounmap_regions(pdev, BIT(1));
409 
410 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
411 	if (!priv) {
412 		dev_err(&pdev->dev, "can't allocate chip data\n");
413 		return -ENOMEM;
414 	}
415 
416 	priv->dev = &pdev->dev;
417 	priv->reg_base = pcim_iomap_table(pdev)[0];
418 
419 	priv->chip.label = dev_name(&pdev->dev);
420 	priv->chip.parent = &pdev->dev;
421 	priv->chip.request = gpiochip_generic_request;
422 	priv->chip.free = gpiochip_generic_free;
423 	priv->chip.direction_input = mrfld_gpio_direction_input;
424 	priv->chip.direction_output = mrfld_gpio_direction_output;
425 	priv->chip.get = mrfld_gpio_get;
426 	priv->chip.set = mrfld_gpio_set;
427 	priv->chip.get_direction = mrfld_gpio_get_direction;
428 	priv->chip.set_config = mrfld_gpio_set_config;
429 	priv->chip.base = gpio_base;
430 	priv->chip.ngpio = MRFLD_NGPIO;
431 	priv->chip.can_sleep = false;
432 
433 	raw_spin_lock_init(&priv->lock);
434 
435 	pci_set_drvdata(pdev, priv);
436 	retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
437 	if (retval) {
438 		dev_err(&pdev->dev, "gpiochip_add error %d\n", retval);
439 		return retval;
440 	}
441 
442 	for (i = 0; i < ARRAY_SIZE(mrfld_gpio_ranges); i++) {
443 		range = &mrfld_gpio_ranges[i];
444 		retval = gpiochip_add_pin_range(&priv->chip,
445 						"pinctrl-merrifield",
446 						range->gpio_base,
447 						range->pin_base,
448 						range->npins);
449 		if (retval) {
450 			dev_err(&pdev->dev, "failed to add GPIO pin range\n");
451 			return retval;
452 		}
453 	}
454 
455 	retval = gpiochip_irqchip_add(&priv->chip, &mrfld_irqchip, irq_base,
456 				      handle_bad_irq, IRQ_TYPE_NONE);
457 	if (retval) {
458 		dev_err(&pdev->dev, "could not connect irqchip to gpiochip\n");
459 		return retval;
460 	}
461 
462 	mrfld_irq_init_hw(priv);
463 
464 	gpiochip_set_chained_irqchip(&priv->chip, &mrfld_irqchip, pdev->irq,
465 				     mrfld_irq_handler);
466 
467 	return 0;
468 }
469 
470 static const struct pci_device_id mrfld_gpio_ids[] = {
471 	{ PCI_VDEVICE(INTEL, 0x1199) },
472 	{ }
473 };
474 MODULE_DEVICE_TABLE(pci, mrfld_gpio_ids);
475 
476 static struct pci_driver mrfld_gpio_driver = {
477 	.name		= "gpio-merrifield",
478 	.id_table	= mrfld_gpio_ids,
479 	.probe		= mrfld_gpio_probe,
480 };
481 
482 module_pci_driver(mrfld_gpio_driver);
483 
484 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
485 MODULE_DESCRIPTION("Intel Merrifield SoC GPIO driver");
486 MODULE_LICENSE("GPL v2");
487