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