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 void mrfld_irq_ack(struct irq_data *d)
165 {
166 	struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);
167 	u32 gpio = irqd_to_hwirq(d);
168 	void __iomem *gisr = gpio_reg(&priv->chip, gpio, GISR);
169 	unsigned long flags;
170 
171 	raw_spin_lock_irqsave(&priv->lock, flags);
172 
173 	writel(BIT(gpio % 32), gisr);
174 
175 	raw_spin_unlock_irqrestore(&priv->lock, flags);
176 }
177 
178 static void mrfld_irq_unmask_mask(struct irq_data *d, bool unmask)
179 {
180 	struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);
181 	u32 gpio = irqd_to_hwirq(d);
182 	void __iomem *gimr = gpio_reg(&priv->chip, gpio, GIMR);
183 	unsigned long flags;
184 	u32 value;
185 
186 	raw_spin_lock_irqsave(&priv->lock, flags);
187 
188 	if (unmask)
189 		value = readl(gimr) | BIT(gpio % 32);
190 	else
191 		value = readl(gimr) & ~BIT(gpio % 32);
192 	writel(value, gimr);
193 
194 	raw_spin_unlock_irqrestore(&priv->lock, flags);
195 }
196 
197 static void mrfld_irq_mask(struct irq_data *d)
198 {
199 	mrfld_irq_unmask_mask(d, false);
200 }
201 
202 static void mrfld_irq_unmask(struct irq_data *d)
203 {
204 	mrfld_irq_unmask_mask(d, true);
205 }
206 
207 static int mrfld_irq_set_type(struct irq_data *d, unsigned int type)
208 {
209 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
210 	struct mrfld_gpio *priv = gpiochip_get_data(gc);
211 	u32 gpio = irqd_to_hwirq(d);
212 	void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
213 	void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
214 	void __iomem *gitr = gpio_reg(&priv->chip, gpio, GITR);
215 	void __iomem *glpr = gpio_reg(&priv->chip, gpio, GLPR);
216 	unsigned long flags;
217 	u32 value;
218 
219 	raw_spin_lock_irqsave(&priv->lock, flags);
220 
221 	if (type & IRQ_TYPE_EDGE_RISING)
222 		value = readl(grer) | BIT(gpio % 32);
223 	else
224 		value = readl(grer) & ~BIT(gpio % 32);
225 	writel(value, grer);
226 
227 	if (type & IRQ_TYPE_EDGE_FALLING)
228 		value = readl(gfer) | BIT(gpio % 32);
229 	else
230 		value = readl(gfer) & ~BIT(gpio % 32);
231 	writel(value, gfer);
232 
233 	/*
234 	 * To prevent glitches from triggering an unintended level interrupt,
235 	 * configure GLPR register first and then configure GITR.
236 	 */
237 	if (type & IRQ_TYPE_LEVEL_LOW)
238 		value = readl(glpr) | BIT(gpio % 32);
239 	else
240 		value = readl(glpr) & ~BIT(gpio % 32);
241 	writel(value, glpr);
242 
243 	if (type & IRQ_TYPE_LEVEL_MASK) {
244 		value = readl(gitr) | BIT(gpio % 32);
245 		writel(value, gitr);
246 
247 		irq_set_handler_locked(d, handle_level_irq);
248 	} else if (type & IRQ_TYPE_EDGE_BOTH) {
249 		value = readl(gitr) & ~BIT(gpio % 32);
250 		writel(value, gitr);
251 
252 		irq_set_handler_locked(d, handle_edge_irq);
253 	}
254 
255 	raw_spin_unlock_irqrestore(&priv->lock, flags);
256 
257 	return 0;
258 }
259 
260 static int mrfld_irq_set_wake(struct irq_data *d, unsigned int on)
261 {
262 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
263 	struct mrfld_gpio *priv = gpiochip_get_data(gc);
264 	u32 gpio = irqd_to_hwirq(d);
265 	void __iomem *gwmr = gpio_reg(&priv->chip, gpio, GWMR);
266 	void __iomem *gwsr = gpio_reg(&priv->chip, gpio, GWSR);
267 	unsigned long flags;
268 	u32 value;
269 
270 	raw_spin_lock_irqsave(&priv->lock, flags);
271 
272 	/* Clear the existing wake status */
273 	writel(BIT(gpio % 32), gwsr);
274 
275 	if (on)
276 		value = readl(gwmr) | BIT(gpio % 32);
277 	else
278 		value = readl(gwmr) & ~BIT(gpio % 32);
279 	writel(value, gwmr);
280 
281 	raw_spin_unlock_irqrestore(&priv->lock, flags);
282 
283 	dev_dbg(priv->dev, "%sable wake for gpio %u\n", on ? "en" : "dis", gpio);
284 	return 0;
285 }
286 
287 static struct irq_chip mrfld_irqchip = {
288 	.name		= "gpio-merrifield",
289 	.irq_ack	= mrfld_irq_ack,
290 	.irq_mask	= mrfld_irq_mask,
291 	.irq_unmask	= mrfld_irq_unmask,
292 	.irq_set_type	= mrfld_irq_set_type,
293 	.irq_set_wake	= mrfld_irq_set_wake,
294 };
295 
296 static void mrfld_irq_handler(struct irq_desc *desc)
297 {
298 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
299 	struct mrfld_gpio *priv = gpiochip_get_data(gc);
300 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
301 	unsigned long base, gpio;
302 
303 	chained_irq_enter(irqchip, desc);
304 
305 	/* Check GPIO controller to check which pin triggered the interrupt */
306 	for (base = 0; base < priv->chip.ngpio; base += 32) {
307 		void __iomem *gisr = gpio_reg(&priv->chip, base, GISR);
308 		void __iomem *gimr = gpio_reg(&priv->chip, base, GIMR);
309 		unsigned long pending, enabled;
310 
311 		pending = readl(gisr);
312 		enabled = readl(gimr);
313 
314 		/* Only interrupts that are enabled */
315 		pending &= enabled;
316 
317 		for_each_set_bit(gpio, &pending, 32) {
318 			unsigned int irq;
319 
320 			irq = irq_find_mapping(gc->irqdomain, base + gpio);
321 			generic_handle_irq(irq);
322 		}
323 	}
324 
325 	chained_irq_exit(irqchip, desc);
326 }
327 
328 static void mrfld_irq_init_hw(struct mrfld_gpio *priv)
329 {
330 	void __iomem *reg;
331 	unsigned int base;
332 
333 	for (base = 0; base < priv->chip.ngpio; base += 32) {
334 		/* Clear the rising-edge detect register */
335 		reg = gpio_reg(&priv->chip, base, GRER);
336 		writel(0, reg);
337 		/* Clear the falling-edge detect register */
338 		reg = gpio_reg(&priv->chip, base, GFER);
339 		writel(0, reg);
340 	}
341 }
342 
343 static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id)
344 {
345 	const struct mrfld_gpio_pinrange *range;
346 	struct mrfld_gpio *priv;
347 	u32 gpio_base, irq_base;
348 	void __iomem *base;
349 	unsigned int i;
350 	int retval;
351 
352 	retval = pcim_enable_device(pdev);
353 	if (retval)
354 		return retval;
355 
356 	retval = pcim_iomap_regions(pdev, BIT(1) | BIT(0), pci_name(pdev));
357 	if (retval) {
358 		dev_err(&pdev->dev, "I/O memory mapping error\n");
359 		return retval;
360 	}
361 
362 	base = pcim_iomap_table(pdev)[1];
363 
364 	irq_base = readl(base);
365 	gpio_base = readl(sizeof(u32) + base);
366 
367 	/* Release the IO mapping, since we already get the info from BAR1 */
368 	pcim_iounmap_regions(pdev, BIT(1));
369 
370 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
371 	if (!priv) {
372 		dev_err(&pdev->dev, "can't allocate chip data\n");
373 		return -ENOMEM;
374 	}
375 
376 	priv->dev = &pdev->dev;
377 	priv->reg_base = pcim_iomap_table(pdev)[0];
378 
379 	priv->chip.label = dev_name(&pdev->dev);
380 	priv->chip.parent = &pdev->dev;
381 	priv->chip.request = gpiochip_generic_request;
382 	priv->chip.free = gpiochip_generic_free;
383 	priv->chip.direction_input = mrfld_gpio_direction_input;
384 	priv->chip.direction_output = mrfld_gpio_direction_output;
385 	priv->chip.get = mrfld_gpio_get;
386 	priv->chip.set = mrfld_gpio_set;
387 	priv->chip.base = gpio_base;
388 	priv->chip.ngpio = MRFLD_NGPIO;
389 	priv->chip.can_sleep = false;
390 
391 	raw_spin_lock_init(&priv->lock);
392 
393 	pci_set_drvdata(pdev, priv);
394 	retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
395 	if (retval) {
396 		dev_err(&pdev->dev, "gpiochip_add error %d\n", retval);
397 		return retval;
398 	}
399 
400 	for (i = 0; i < ARRAY_SIZE(mrfld_gpio_ranges); i++) {
401 		range = &mrfld_gpio_ranges[i];
402 		retval = gpiochip_add_pin_range(&priv->chip,
403 						"pinctrl-merrifield",
404 						range->gpio_base,
405 						range->pin_base,
406 						range->npins);
407 		if (retval) {
408 			dev_err(&pdev->dev, "failed to add GPIO pin range\n");
409 			return retval;
410 		}
411 	}
412 
413 	retval = gpiochip_irqchip_add(&priv->chip, &mrfld_irqchip, irq_base,
414 				      handle_simple_irq, IRQ_TYPE_NONE);
415 	if (retval) {
416 		dev_err(&pdev->dev, "could not connect irqchip to gpiochip\n");
417 		return retval;
418 	}
419 
420 	mrfld_irq_init_hw(priv);
421 
422 	gpiochip_set_chained_irqchip(&priv->chip, &mrfld_irqchip, pdev->irq,
423 				     mrfld_irq_handler);
424 
425 	return 0;
426 }
427 
428 static const struct pci_device_id mrfld_gpio_ids[] = {
429 	{ PCI_VDEVICE(INTEL, 0x1199) },
430 	{ }
431 };
432 MODULE_DEVICE_TABLE(pci, mrfld_gpio_ids);
433 
434 static struct pci_driver mrfld_gpio_driver = {
435 	.name		= "gpio-merrifield",
436 	.id_table	= mrfld_gpio_ids,
437 	.probe		= mrfld_gpio_probe,
438 };
439 
440 module_pci_driver(mrfld_gpio_driver);
441 
442 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
443 MODULE_DESCRIPTION("Intel Merrifield SoC GPIO driver");
444 MODULE_LICENSE("GPL v2");
445