xref: /openbmc/linux/drivers/gpio/gpio-em.c (revision afb46f79)
1 /*
2  * Emma Mobile GPIO Support - GIO
3  *
4  *  Copyright (C) 2012 Magnus Damm
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License
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  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 
20 #include <linux/init.h>
21 #include <linux/platform_device.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/io.h>
26 #include <linux/irq.h>
27 #include <linux/irqdomain.h>
28 #include <linux/bitops.h>
29 #include <linux/err.h>
30 #include <linux/gpio.h>
31 #include <linux/slab.h>
32 #include <linux/module.h>
33 #include <linux/pinctrl/consumer.h>
34 #include <linux/platform_data/gpio-em.h>
35 
36 struct em_gio_priv {
37 	void __iomem *base0;
38 	void __iomem *base1;
39 	spinlock_t sense_lock;
40 	struct platform_device *pdev;
41 	struct gpio_chip gpio_chip;
42 	struct irq_chip irq_chip;
43 	struct irq_domain *irq_domain;
44 };
45 
46 #define GIO_E1 0x00
47 #define GIO_E0 0x04
48 #define GIO_EM 0x04
49 #define GIO_OL 0x08
50 #define GIO_OH 0x0c
51 #define GIO_I 0x10
52 #define GIO_IIA 0x14
53 #define GIO_IEN 0x18
54 #define GIO_IDS 0x1c
55 #define GIO_IIM 0x1c
56 #define GIO_RAW 0x20
57 #define GIO_MST 0x24
58 #define GIO_IIR 0x28
59 
60 #define GIO_IDT0 0x40
61 #define GIO_IDT1 0x44
62 #define GIO_IDT2 0x48
63 #define GIO_IDT3 0x4c
64 #define GIO_RAWBL 0x50
65 #define GIO_RAWBH 0x54
66 #define GIO_IRBL 0x58
67 #define GIO_IRBH 0x5c
68 
69 #define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))
70 
71 static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
72 {
73 	if (offs < GIO_IDT0)
74 		return ioread32(p->base0 + offs);
75 	else
76 		return ioread32(p->base1 + (offs - GIO_IDT0));
77 }
78 
79 static inline void em_gio_write(struct em_gio_priv *p, int offs,
80 				unsigned long value)
81 {
82 	if (offs < GIO_IDT0)
83 		iowrite32(value, p->base0 + offs);
84 	else
85 		iowrite32(value, p->base1 + (offs - GIO_IDT0));
86 }
87 
88 static void em_gio_irq_disable(struct irq_data *d)
89 {
90 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
91 
92 	em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
93 }
94 
95 static void em_gio_irq_enable(struct irq_data *d)
96 {
97 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
98 
99 	em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
100 }
101 
102 static int em_gio_irq_reqres(struct irq_data *d)
103 {
104 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
105 
106 	if (gpio_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d))) {
107 		dev_err(p->gpio_chip.dev,
108 			"unable to lock HW IRQ %lu for IRQ\n",
109 			irqd_to_hwirq(d));
110 		return -EINVAL;
111 	}
112 	return 0;
113 }
114 
115 static void em_gio_irq_relres(struct irq_data *d)
116 {
117 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
118 
119 	gpio_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
120 }
121 
122 
123 #define GIO_ASYNC(x) (x + 8)
124 
125 static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
126 	[IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
127 	[IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
128 	[IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
129 	[IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
130 	[IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
131 };
132 
133 static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
134 {
135 	unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
136 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
137 	unsigned int reg, offset, shift;
138 	unsigned long flags;
139 	unsigned long tmp;
140 
141 	if (!value)
142 		return -EINVAL;
143 
144 	offset = irqd_to_hwirq(d);
145 
146 	pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
147 
148 	/* 8 x 4 bit fields in 4 IDT registers */
149 	reg = GIO_IDT(offset >> 3);
150 	shift = (offset & 0x07) << 4;
151 
152 	spin_lock_irqsave(&p->sense_lock, flags);
153 
154 	/* disable the interrupt in IIA */
155 	tmp = em_gio_read(p, GIO_IIA);
156 	tmp &= ~BIT(offset);
157 	em_gio_write(p, GIO_IIA, tmp);
158 
159 	/* change the sense setting in IDT */
160 	tmp = em_gio_read(p, reg);
161 	tmp &= ~(0xf << shift);
162 	tmp |= value << shift;
163 	em_gio_write(p, reg, tmp);
164 
165 	/* clear pending interrupts */
166 	em_gio_write(p, GIO_IIR, BIT(offset));
167 
168 	/* enable the interrupt in IIA */
169 	tmp = em_gio_read(p, GIO_IIA);
170 	tmp |= BIT(offset);
171 	em_gio_write(p, GIO_IIA, tmp);
172 
173 	spin_unlock_irqrestore(&p->sense_lock, flags);
174 
175 	return 0;
176 }
177 
178 static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
179 {
180 	struct em_gio_priv *p = dev_id;
181 	unsigned long pending;
182 	unsigned int offset, irqs_handled = 0;
183 
184 	while ((pending = em_gio_read(p, GIO_MST))) {
185 		offset = __ffs(pending);
186 		em_gio_write(p, GIO_IIR, BIT(offset));
187 		generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
188 		irqs_handled++;
189 	}
190 
191 	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
192 }
193 
194 static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
195 {
196 	return container_of(chip, struct em_gio_priv, gpio_chip);
197 }
198 
199 static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
200 {
201 	em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
202 	return 0;
203 }
204 
205 static int em_gio_get(struct gpio_chip *chip, unsigned offset)
206 {
207 	return (int)(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
208 }
209 
210 static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
211 			 unsigned shift, int value)
212 {
213 	/* upper 16 bits contains mask and lower 16 actual value */
214 	em_gio_write(gpio_to_priv(chip), reg,
215 		     (1 << (shift + 16)) | (value << shift));
216 }
217 
218 static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
219 {
220 	/* output is split into two registers */
221 	if (offset < 16)
222 		__em_gio_set(chip, GIO_OL, offset, value);
223 	else
224 		__em_gio_set(chip, GIO_OH, offset - 16, value);
225 }
226 
227 static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
228 				   int value)
229 {
230 	/* write GPIO value to output before selecting output mode of pin */
231 	em_gio_set(chip, offset, value);
232 	em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
233 	return 0;
234 }
235 
236 static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
237 {
238 	return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
239 }
240 
241 static int em_gio_request(struct gpio_chip *chip, unsigned offset)
242 {
243 	return pinctrl_request_gpio(chip->base + offset);
244 }
245 
246 static void em_gio_free(struct gpio_chip *chip, unsigned offset)
247 {
248 	pinctrl_free_gpio(chip->base + offset);
249 
250 	/* Set the GPIO as an input to ensure that the next GPIO request won't
251 	* drive the GPIO pin as an output.
252 	*/
253 	em_gio_direction_input(chip, offset);
254 }
255 
256 static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int irq,
257 				 irq_hw_number_t hwirq)
258 {
259 	struct em_gio_priv *p = h->host_data;
260 
261 	pr_debug("gio: map hw irq = %d, irq = %d\n", (int)hwirq, irq);
262 
263 	irq_set_chip_data(irq, h->host_data);
264 	irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
265 	set_irq_flags(irq, IRQF_VALID); /* kill me now */
266 	return 0;
267 }
268 
269 static struct irq_domain_ops em_gio_irq_domain_ops = {
270 	.map	= em_gio_irq_domain_map,
271 	.xlate	= irq_domain_xlate_twocell,
272 };
273 
274 static int em_gio_probe(struct platform_device *pdev)
275 {
276 	struct gpio_em_config pdata_dt;
277 	struct gpio_em_config *pdata = dev_get_platdata(&pdev->dev);
278 	struct em_gio_priv *p;
279 	struct resource *io[2], *irq[2];
280 	struct gpio_chip *gpio_chip;
281 	struct irq_chip *irq_chip;
282 	const char *name = dev_name(&pdev->dev);
283 	int ret;
284 
285 	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
286 	if (!p) {
287 		dev_err(&pdev->dev, "failed to allocate driver data\n");
288 		ret = -ENOMEM;
289 		goto err0;
290 	}
291 
292 	p->pdev = pdev;
293 	platform_set_drvdata(pdev, p);
294 	spin_lock_init(&p->sense_lock);
295 
296 	io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297 	io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
298 	irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
299 	irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
300 
301 	if (!io[0] || !io[1] || !irq[0] || !irq[1]) {
302 		dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
303 		ret = -EINVAL;
304 		goto err0;
305 	}
306 
307 	p->base0 = devm_ioremap_nocache(&pdev->dev, io[0]->start,
308 					resource_size(io[0]));
309 	if (!p->base0) {
310 		dev_err(&pdev->dev, "failed to remap low I/O memory\n");
311 		ret = -ENXIO;
312 		goto err0;
313 	}
314 
315 	p->base1 = devm_ioremap_nocache(&pdev->dev, io[1]->start,
316 				   resource_size(io[1]));
317 	if (!p->base1) {
318 		dev_err(&pdev->dev, "failed to remap high I/O memory\n");
319 		ret = -ENXIO;
320 		goto err0;
321 	}
322 
323 	if (!pdata) {
324 		memset(&pdata_dt, 0, sizeof(pdata_dt));
325 		pdata = &pdata_dt;
326 
327 		if (of_property_read_u32(pdev->dev.of_node, "ngpios",
328 					 &pdata->number_of_pins)) {
329 			dev_err(&pdev->dev, "Missing ngpios OF property\n");
330 			ret = -EINVAL;
331 			goto err0;
332 		}
333 
334 		ret = of_alias_get_id(pdev->dev.of_node, "gpio");
335 		if (ret < 0) {
336 			dev_err(&pdev->dev, "Couldn't get OF id\n");
337 			goto err0;
338 		}
339 		pdata->gpio_base = ret * 32; /* 32 GPIOs per instance */
340 	}
341 
342 	gpio_chip = &p->gpio_chip;
343 	gpio_chip->of_node = pdev->dev.of_node;
344 	gpio_chip->direction_input = em_gio_direction_input;
345 	gpio_chip->get = em_gio_get;
346 	gpio_chip->direction_output = em_gio_direction_output;
347 	gpio_chip->set = em_gio_set;
348 	gpio_chip->to_irq = em_gio_to_irq;
349 	gpio_chip->request = em_gio_request;
350 	gpio_chip->free = em_gio_free;
351 	gpio_chip->label = name;
352 	gpio_chip->dev = &pdev->dev;
353 	gpio_chip->owner = THIS_MODULE;
354 	gpio_chip->base = pdata->gpio_base;
355 	gpio_chip->ngpio = pdata->number_of_pins;
356 
357 	irq_chip = &p->irq_chip;
358 	irq_chip->name = name;
359 	irq_chip->irq_mask = em_gio_irq_disable;
360 	irq_chip->irq_unmask = em_gio_irq_enable;
361 	irq_chip->irq_set_type = em_gio_irq_set_type;
362 	irq_chip->irq_request_resources = em_gio_irq_reqres;
363 	irq_chip->irq_release_resources = em_gio_irq_relres;
364 	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;
365 
366 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
367 					      pdata->number_of_pins,
368 					      pdata->irq_base,
369 					      &em_gio_irq_domain_ops, p);
370 	if (!p->irq_domain) {
371 		ret = -ENXIO;
372 		dev_err(&pdev->dev, "cannot initialize irq domain\n");
373 		goto err0;
374 	}
375 
376 	if (devm_request_irq(&pdev->dev, irq[0]->start,
377 			     em_gio_irq_handler, 0, name, p)) {
378 		dev_err(&pdev->dev, "failed to request low IRQ\n");
379 		ret = -ENOENT;
380 		goto err1;
381 	}
382 
383 	if (devm_request_irq(&pdev->dev, irq[1]->start,
384 			     em_gio_irq_handler, 0, name, p)) {
385 		dev_err(&pdev->dev, "failed to request high IRQ\n");
386 		ret = -ENOENT;
387 		goto err1;
388 	}
389 
390 	ret = gpiochip_add(gpio_chip);
391 	if (ret) {
392 		dev_err(&pdev->dev, "failed to add GPIO controller\n");
393 		goto err1;
394 	}
395 
396 	if (pdata->pctl_name) {
397 		ret = gpiochip_add_pin_range(gpio_chip, pdata->pctl_name, 0,
398 					     gpio_chip->base, gpio_chip->ngpio);
399 		if (ret < 0)
400 			dev_warn(&pdev->dev, "failed to add pin range\n");
401 	}
402 	return 0;
403 
404 err1:
405 	irq_domain_remove(p->irq_domain);
406 err0:
407 	return ret;
408 }
409 
410 static int em_gio_remove(struct platform_device *pdev)
411 {
412 	struct em_gio_priv *p = platform_get_drvdata(pdev);
413 	int ret;
414 
415 	ret = gpiochip_remove(&p->gpio_chip);
416 	if (ret)
417 		return ret;
418 
419 	irq_domain_remove(p->irq_domain);
420 	return 0;
421 }
422 
423 static const struct of_device_id em_gio_dt_ids[] = {
424 	{ .compatible = "renesas,em-gio", },
425 	{},
426 };
427 MODULE_DEVICE_TABLE(of, em_gio_dt_ids);
428 
429 static struct platform_driver em_gio_device_driver = {
430 	.probe		= em_gio_probe,
431 	.remove		= em_gio_remove,
432 	.driver		= {
433 		.name	= "em_gio",
434 		.of_match_table = em_gio_dt_ids,
435 		.owner		= THIS_MODULE,
436 	}
437 };
438 
439 static int __init em_gio_init(void)
440 {
441 	return platform_driver_register(&em_gio_device_driver);
442 }
443 postcore_initcall(em_gio_init);
444 
445 static void __exit em_gio_exit(void)
446 {
447 	platform_driver_unregister(&em_gio_device_driver);
448 }
449 module_exit(em_gio_exit);
450 
451 MODULE_AUTHOR("Magnus Damm");
452 MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
453 MODULE_LICENSE("GPL v2");
454