xref: /openbmc/linux/drivers/gpio/gpio-em.c (revision 5bd8e16d)
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 #define GIO_ASYNC(x) (x + 8)
103 
104 static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
105 	[IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
106 	[IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
107 	[IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
108 	[IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
109 	[IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
110 };
111 
112 static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
113 {
114 	unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
115 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
116 	unsigned int reg, offset, shift;
117 	unsigned long flags;
118 	unsigned long tmp;
119 
120 	if (!value)
121 		return -EINVAL;
122 
123 	offset = irqd_to_hwirq(d);
124 
125 	pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
126 
127 	/* 8 x 4 bit fields in 4 IDT registers */
128 	reg = GIO_IDT(offset >> 3);
129 	shift = (offset & 0x07) << 4;
130 
131 	spin_lock_irqsave(&p->sense_lock, flags);
132 
133 	/* disable the interrupt in IIA */
134 	tmp = em_gio_read(p, GIO_IIA);
135 	tmp &= ~BIT(offset);
136 	em_gio_write(p, GIO_IIA, tmp);
137 
138 	/* change the sense setting in IDT */
139 	tmp = em_gio_read(p, reg);
140 	tmp &= ~(0xf << shift);
141 	tmp |= value << shift;
142 	em_gio_write(p, reg, tmp);
143 
144 	/* clear pending interrupts */
145 	em_gio_write(p, GIO_IIR, BIT(offset));
146 
147 	/* enable the interrupt in IIA */
148 	tmp = em_gio_read(p, GIO_IIA);
149 	tmp |= BIT(offset);
150 	em_gio_write(p, GIO_IIA, tmp);
151 
152 	spin_unlock_irqrestore(&p->sense_lock, flags);
153 
154 	return 0;
155 }
156 
157 static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
158 {
159 	struct em_gio_priv *p = dev_id;
160 	unsigned long pending;
161 	unsigned int offset, irqs_handled = 0;
162 
163 	while ((pending = em_gio_read(p, GIO_MST))) {
164 		offset = __ffs(pending);
165 		em_gio_write(p, GIO_IIR, BIT(offset));
166 		generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
167 		irqs_handled++;
168 	}
169 
170 	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
171 }
172 
173 static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
174 {
175 	return container_of(chip, struct em_gio_priv, gpio_chip);
176 }
177 
178 static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
179 {
180 	em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
181 	return 0;
182 }
183 
184 static int em_gio_get(struct gpio_chip *chip, unsigned offset)
185 {
186 	return (int)(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
187 }
188 
189 static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
190 			 unsigned shift, int value)
191 {
192 	/* upper 16 bits contains mask and lower 16 actual value */
193 	em_gio_write(gpio_to_priv(chip), reg,
194 		     (1 << (shift + 16)) | (value << shift));
195 }
196 
197 static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
198 {
199 	/* output is split into two registers */
200 	if (offset < 16)
201 		__em_gio_set(chip, GIO_OL, offset, value);
202 	else
203 		__em_gio_set(chip, GIO_OH, offset - 16, value);
204 }
205 
206 static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
207 				   int value)
208 {
209 	/* write GPIO value to output before selecting output mode of pin */
210 	em_gio_set(chip, offset, value);
211 	em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
212 	return 0;
213 }
214 
215 static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
216 {
217 	return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
218 }
219 
220 static int em_gio_request(struct gpio_chip *chip, unsigned offset)
221 {
222 	return pinctrl_request_gpio(chip->base + offset);
223 }
224 
225 static void em_gio_free(struct gpio_chip *chip, unsigned offset)
226 {
227 	pinctrl_free_gpio(chip->base + offset);
228 
229 	/* Set the GPIO as an input to ensure that the next GPIO request won't
230 	* drive the GPIO pin as an output.
231 	*/
232 	em_gio_direction_input(chip, offset);
233 }
234 
235 static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int virq,
236 				 irq_hw_number_t hw)
237 {
238 	struct em_gio_priv *p = h->host_data;
239 
240 	pr_debug("gio: map hw irq = %d, virq = %d\n", (int)hw, virq);
241 
242 	irq_set_chip_data(virq, h->host_data);
243 	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
244 	set_irq_flags(virq, IRQF_VALID); /* kill me now */
245 	return 0;
246 }
247 
248 static struct irq_domain_ops em_gio_irq_domain_ops = {
249 	.map	= em_gio_irq_domain_map,
250 	.xlate	= irq_domain_xlate_twocell,
251 };
252 
253 static int em_gio_probe(struct platform_device *pdev)
254 {
255 	struct gpio_em_config pdata_dt;
256 	struct gpio_em_config *pdata = dev_get_platdata(&pdev->dev);
257 	struct em_gio_priv *p;
258 	struct resource *io[2], *irq[2];
259 	struct gpio_chip *gpio_chip;
260 	struct irq_chip *irq_chip;
261 	const char *name = dev_name(&pdev->dev);
262 	int ret;
263 
264 	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
265 	if (!p) {
266 		dev_err(&pdev->dev, "failed to allocate driver data\n");
267 		ret = -ENOMEM;
268 		goto err0;
269 	}
270 
271 	p->pdev = pdev;
272 	platform_set_drvdata(pdev, p);
273 	spin_lock_init(&p->sense_lock);
274 
275 	io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
276 	io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
277 	irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
278 	irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
279 
280 	if (!io[0] || !io[1] || !irq[0] || !irq[1]) {
281 		dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
282 		ret = -EINVAL;
283 		goto err0;
284 	}
285 
286 	p->base0 = devm_ioremap_nocache(&pdev->dev, io[0]->start,
287 					resource_size(io[0]));
288 	if (!p->base0) {
289 		dev_err(&pdev->dev, "failed to remap low I/O memory\n");
290 		ret = -ENXIO;
291 		goto err0;
292 	}
293 
294 	p->base1 = devm_ioremap_nocache(&pdev->dev, io[1]->start,
295 				   resource_size(io[1]));
296 	if (!p->base1) {
297 		dev_err(&pdev->dev, "failed to remap high I/O memory\n");
298 		ret = -ENXIO;
299 		goto err0;
300 	}
301 
302 	if (!pdata) {
303 		memset(&pdata_dt, 0, sizeof(pdata_dt));
304 		pdata = &pdata_dt;
305 
306 		if (of_property_read_u32(pdev->dev.of_node, "ngpios",
307 					 &pdata->number_of_pins)) {
308 			dev_err(&pdev->dev, "Missing ngpios OF property\n");
309 			ret = -EINVAL;
310 			goto err0;
311 		}
312 
313 		ret = of_alias_get_id(pdev->dev.of_node, "gpio");
314 		if (ret < 0) {
315 			dev_err(&pdev->dev, "Couldn't get OF id\n");
316 			goto err0;
317 		}
318 		pdata->gpio_base = ret * 32; /* 32 GPIOs per instance */
319 	}
320 
321 	gpio_chip = &p->gpio_chip;
322 	gpio_chip->direction_input = em_gio_direction_input;
323 	gpio_chip->get = em_gio_get;
324 	gpio_chip->direction_output = em_gio_direction_output;
325 	gpio_chip->set = em_gio_set;
326 	gpio_chip->to_irq = em_gio_to_irq;
327 	gpio_chip->request = em_gio_request;
328 	gpio_chip->free = em_gio_free;
329 	gpio_chip->label = name;
330 	gpio_chip->owner = THIS_MODULE;
331 	gpio_chip->base = pdata->gpio_base;
332 	gpio_chip->ngpio = pdata->number_of_pins;
333 
334 	irq_chip = &p->irq_chip;
335 	irq_chip->name = name;
336 	irq_chip->irq_mask = em_gio_irq_disable;
337 	irq_chip->irq_unmask = em_gio_irq_enable;
338 	irq_chip->irq_enable = em_gio_irq_enable;
339 	irq_chip->irq_disable = em_gio_irq_disable;
340 	irq_chip->irq_set_type = em_gio_irq_set_type;
341 	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE;
342 
343 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
344 					      pdata->number_of_pins,
345 					      pdata->irq_base,
346 					      &em_gio_irq_domain_ops, p);
347 	if (!p->irq_domain) {
348 		ret = -ENXIO;
349 		dev_err(&pdev->dev, "cannot initialize irq domain\n");
350 		goto err0;
351 	}
352 
353 	if (devm_request_irq(&pdev->dev, irq[0]->start,
354 			     em_gio_irq_handler, 0, name, p)) {
355 		dev_err(&pdev->dev, "failed to request low IRQ\n");
356 		ret = -ENOENT;
357 		goto err1;
358 	}
359 
360 	if (devm_request_irq(&pdev->dev, irq[1]->start,
361 			     em_gio_irq_handler, 0, name, p)) {
362 		dev_err(&pdev->dev, "failed to request high IRQ\n");
363 		ret = -ENOENT;
364 		goto err1;
365 	}
366 
367 	ret = gpiochip_add(gpio_chip);
368 	if (ret) {
369 		dev_err(&pdev->dev, "failed to add GPIO controller\n");
370 		goto err1;
371 	}
372 
373 	if (pdata->pctl_name) {
374 		ret = gpiochip_add_pin_range(gpio_chip, pdata->pctl_name, 0,
375 					     gpio_chip->base, gpio_chip->ngpio);
376 		if (ret < 0)
377 			dev_warn(&pdev->dev, "failed to add pin range\n");
378 	}
379 	return 0;
380 
381 err1:
382 	irq_domain_remove(p->irq_domain);
383 err0:
384 	return ret;
385 }
386 
387 static int em_gio_remove(struct platform_device *pdev)
388 {
389 	struct em_gio_priv *p = platform_get_drvdata(pdev);
390 	int ret;
391 
392 	ret = gpiochip_remove(&p->gpio_chip);
393 	if (ret)
394 		return ret;
395 
396 	irq_domain_remove(p->irq_domain);
397 	return 0;
398 }
399 
400 static const struct of_device_id em_gio_dt_ids[] = {
401 	{ .compatible = "renesas,em-gio", },
402 	{},
403 };
404 MODULE_DEVICE_TABLE(of, em_gio_dt_ids);
405 
406 static struct platform_driver em_gio_device_driver = {
407 	.probe		= em_gio_probe,
408 	.remove		= em_gio_remove,
409 	.driver		= {
410 		.name	= "em_gio",
411 		.of_match_table = em_gio_dt_ids,
412 		.owner		= THIS_MODULE,
413 	}
414 };
415 
416 static int __init em_gio_init(void)
417 {
418 	return platform_driver_register(&em_gio_device_driver);
419 }
420 postcore_initcall(em_gio_init);
421 
422 static void __exit em_gio_exit(void)
423 {
424 	platform_driver_unregister(&em_gio_device_driver);
425 }
426 module_exit(em_gio_exit);
427 
428 MODULE_AUTHOR("Magnus Damm");
429 MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
430 MODULE_LICENSE("GPL v2");
431