xref: /openbmc/linux/drivers/gpio/gpio-mxc.c (revision 95e9fd10)
1 /*
2  * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
3  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
4  *
5  * Based on code from Freescale,
6  * Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * as published by the Free Software Foundation; either version 2
11  * of the License, or (at your option) any later version.
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
20  */
21 
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/irq.h>
26 #include <linux/irqdomain.h>
27 #include <linux/gpio.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
30 #include <linux/basic_mmio_gpio.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 #include <linux/module.h>
34 #include <asm-generic/bug.h>
35 #include <asm/mach/irq.h>
36 
37 enum mxc_gpio_hwtype {
38 	IMX1_GPIO,	/* runs on i.mx1 */
39 	IMX21_GPIO,	/* runs on i.mx21 and i.mx27 */
40 	IMX31_GPIO,	/* runs on i.mx31 */
41 	IMX35_GPIO,	/* runs on all other i.mx */
42 };
43 
44 /* device type dependent stuff */
45 struct mxc_gpio_hwdata {
46 	unsigned dr_reg;
47 	unsigned gdir_reg;
48 	unsigned psr_reg;
49 	unsigned icr1_reg;
50 	unsigned icr2_reg;
51 	unsigned imr_reg;
52 	unsigned isr_reg;
53 	int edge_sel_reg;
54 	unsigned low_level;
55 	unsigned high_level;
56 	unsigned rise_edge;
57 	unsigned fall_edge;
58 };
59 
60 struct mxc_gpio_port {
61 	struct list_head node;
62 	void __iomem *base;
63 	int irq;
64 	int irq_high;
65 	struct irq_domain *domain;
66 	struct bgpio_chip bgc;
67 	u32 both_edges;
68 };
69 
70 static struct mxc_gpio_hwdata imx1_imx21_gpio_hwdata = {
71 	.dr_reg		= 0x1c,
72 	.gdir_reg	= 0x00,
73 	.psr_reg	= 0x24,
74 	.icr1_reg	= 0x28,
75 	.icr2_reg	= 0x2c,
76 	.imr_reg	= 0x30,
77 	.isr_reg	= 0x34,
78 	.edge_sel_reg	= -EINVAL,
79 	.low_level	= 0x03,
80 	.high_level	= 0x02,
81 	.rise_edge	= 0x00,
82 	.fall_edge	= 0x01,
83 };
84 
85 static struct mxc_gpio_hwdata imx31_gpio_hwdata = {
86 	.dr_reg		= 0x00,
87 	.gdir_reg	= 0x04,
88 	.psr_reg	= 0x08,
89 	.icr1_reg	= 0x0c,
90 	.icr2_reg	= 0x10,
91 	.imr_reg	= 0x14,
92 	.isr_reg	= 0x18,
93 	.edge_sel_reg	= -EINVAL,
94 	.low_level	= 0x00,
95 	.high_level	= 0x01,
96 	.rise_edge	= 0x02,
97 	.fall_edge	= 0x03,
98 };
99 
100 static struct mxc_gpio_hwdata imx35_gpio_hwdata = {
101 	.dr_reg		= 0x00,
102 	.gdir_reg	= 0x04,
103 	.psr_reg	= 0x08,
104 	.icr1_reg	= 0x0c,
105 	.icr2_reg	= 0x10,
106 	.imr_reg	= 0x14,
107 	.isr_reg	= 0x18,
108 	.edge_sel_reg	= 0x1c,
109 	.low_level	= 0x00,
110 	.high_level	= 0x01,
111 	.rise_edge	= 0x02,
112 	.fall_edge	= 0x03,
113 };
114 
115 static enum mxc_gpio_hwtype mxc_gpio_hwtype;
116 static struct mxc_gpio_hwdata *mxc_gpio_hwdata;
117 
118 #define GPIO_DR			(mxc_gpio_hwdata->dr_reg)
119 #define GPIO_GDIR		(mxc_gpio_hwdata->gdir_reg)
120 #define GPIO_PSR		(mxc_gpio_hwdata->psr_reg)
121 #define GPIO_ICR1		(mxc_gpio_hwdata->icr1_reg)
122 #define GPIO_ICR2		(mxc_gpio_hwdata->icr2_reg)
123 #define GPIO_IMR		(mxc_gpio_hwdata->imr_reg)
124 #define GPIO_ISR		(mxc_gpio_hwdata->isr_reg)
125 #define GPIO_EDGE_SEL		(mxc_gpio_hwdata->edge_sel_reg)
126 
127 #define GPIO_INT_LOW_LEV	(mxc_gpio_hwdata->low_level)
128 #define GPIO_INT_HIGH_LEV	(mxc_gpio_hwdata->high_level)
129 #define GPIO_INT_RISE_EDGE	(mxc_gpio_hwdata->rise_edge)
130 #define GPIO_INT_FALL_EDGE	(mxc_gpio_hwdata->fall_edge)
131 #define GPIO_INT_BOTH_EDGES	0x4
132 
133 static struct platform_device_id mxc_gpio_devtype[] = {
134 	{
135 		.name = "imx1-gpio",
136 		.driver_data = IMX1_GPIO,
137 	}, {
138 		.name = "imx21-gpio",
139 		.driver_data = IMX21_GPIO,
140 	}, {
141 		.name = "imx31-gpio",
142 		.driver_data = IMX31_GPIO,
143 	}, {
144 		.name = "imx35-gpio",
145 		.driver_data = IMX35_GPIO,
146 	}, {
147 		/* sentinel */
148 	}
149 };
150 
151 static const struct of_device_id mxc_gpio_dt_ids[] = {
152 	{ .compatible = "fsl,imx1-gpio", .data = &mxc_gpio_devtype[IMX1_GPIO], },
153 	{ .compatible = "fsl,imx21-gpio", .data = &mxc_gpio_devtype[IMX21_GPIO], },
154 	{ .compatible = "fsl,imx31-gpio", .data = &mxc_gpio_devtype[IMX31_GPIO], },
155 	{ .compatible = "fsl,imx35-gpio", .data = &mxc_gpio_devtype[IMX35_GPIO], },
156 	{ /* sentinel */ }
157 };
158 
159 /*
160  * MX2 has one interrupt *for all* gpio ports. The list is used
161  * to save the references to all ports, so that mx2_gpio_irq_handler
162  * can walk through all interrupt status registers.
163  */
164 static LIST_HEAD(mxc_gpio_ports);
165 
166 /* Note: This driver assumes 32 GPIOs are handled in one register */
167 
168 static int gpio_set_irq_type(struct irq_data *d, u32 type)
169 {
170 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
171 	struct mxc_gpio_port *port = gc->private;
172 	u32 bit, val;
173 	u32 gpio_idx = d->hwirq;
174 	u32 gpio = port->bgc.gc.base + gpio_idx;
175 	int edge;
176 	void __iomem *reg = port->base;
177 
178 	port->both_edges &= ~(1 << gpio_idx);
179 	switch (type) {
180 	case IRQ_TYPE_EDGE_RISING:
181 		edge = GPIO_INT_RISE_EDGE;
182 		break;
183 	case IRQ_TYPE_EDGE_FALLING:
184 		edge = GPIO_INT_FALL_EDGE;
185 		break;
186 	case IRQ_TYPE_EDGE_BOTH:
187 		if (GPIO_EDGE_SEL >= 0) {
188 			edge = GPIO_INT_BOTH_EDGES;
189 		} else {
190 			val = gpio_get_value(gpio);
191 			if (val) {
192 				edge = GPIO_INT_LOW_LEV;
193 				pr_debug("mxc: set GPIO %d to low trigger\n", gpio);
194 			} else {
195 				edge = GPIO_INT_HIGH_LEV;
196 				pr_debug("mxc: set GPIO %d to high trigger\n", gpio);
197 			}
198 			port->both_edges |= 1 << gpio_idx;
199 		}
200 		break;
201 	case IRQ_TYPE_LEVEL_LOW:
202 		edge = GPIO_INT_LOW_LEV;
203 		break;
204 	case IRQ_TYPE_LEVEL_HIGH:
205 		edge = GPIO_INT_HIGH_LEV;
206 		break;
207 	default:
208 		return -EINVAL;
209 	}
210 
211 	if (GPIO_EDGE_SEL >= 0) {
212 		val = readl(port->base + GPIO_EDGE_SEL);
213 		if (edge == GPIO_INT_BOTH_EDGES)
214 			writel(val | (1 << gpio_idx),
215 				port->base + GPIO_EDGE_SEL);
216 		else
217 			writel(val & ~(1 << gpio_idx),
218 				port->base + GPIO_EDGE_SEL);
219 	}
220 
221 	if (edge != GPIO_INT_BOTH_EDGES) {
222 		reg += GPIO_ICR1 + ((gpio_idx & 0x10) >> 2); /* lower or upper register */
223 		bit = gpio_idx & 0xf;
224 		val = readl(reg) & ~(0x3 << (bit << 1));
225 		writel(val | (edge << (bit << 1)), reg);
226 	}
227 
228 	writel(1 << gpio_idx, port->base + GPIO_ISR);
229 
230 	return 0;
231 }
232 
233 static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
234 {
235 	void __iomem *reg = port->base;
236 	u32 bit, val;
237 	int edge;
238 
239 	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
240 	bit = gpio & 0xf;
241 	val = readl(reg);
242 	edge = (val >> (bit << 1)) & 3;
243 	val &= ~(0x3 << (bit << 1));
244 	if (edge == GPIO_INT_HIGH_LEV) {
245 		edge = GPIO_INT_LOW_LEV;
246 		pr_debug("mxc: switch GPIO %d to low trigger\n", gpio);
247 	} else if (edge == GPIO_INT_LOW_LEV) {
248 		edge = GPIO_INT_HIGH_LEV;
249 		pr_debug("mxc: switch GPIO %d to high trigger\n", gpio);
250 	} else {
251 		pr_err("mxc: invalid configuration for GPIO %d: %x\n",
252 		       gpio, edge);
253 		return;
254 	}
255 	writel(val | (edge << (bit << 1)), reg);
256 }
257 
258 /* handle 32 interrupts in one status register */
259 static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
260 {
261 	while (irq_stat != 0) {
262 		int irqoffset = fls(irq_stat) - 1;
263 
264 		if (port->both_edges & (1 << irqoffset))
265 			mxc_flip_edge(port, irqoffset);
266 
267 		generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
268 
269 		irq_stat &= ~(1 << irqoffset);
270 	}
271 }
272 
273 /* MX1 and MX3 has one interrupt *per* gpio port */
274 static void mx3_gpio_irq_handler(u32 irq, struct irq_desc *desc)
275 {
276 	u32 irq_stat;
277 	struct mxc_gpio_port *port = irq_get_handler_data(irq);
278 	struct irq_chip *chip = irq_get_chip(irq);
279 
280 	chained_irq_enter(chip, desc);
281 
282 	irq_stat = readl(port->base + GPIO_ISR) & readl(port->base + GPIO_IMR);
283 
284 	mxc_gpio_irq_handler(port, irq_stat);
285 
286 	chained_irq_exit(chip, desc);
287 }
288 
289 /* MX2 has one interrupt *for all* gpio ports */
290 static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc)
291 {
292 	u32 irq_msk, irq_stat;
293 	struct mxc_gpio_port *port;
294 
295 	/* walk through all interrupt status registers */
296 	list_for_each_entry(port, &mxc_gpio_ports, node) {
297 		irq_msk = readl(port->base + GPIO_IMR);
298 		if (!irq_msk)
299 			continue;
300 
301 		irq_stat = readl(port->base + GPIO_ISR) & irq_msk;
302 		if (irq_stat)
303 			mxc_gpio_irq_handler(port, irq_stat);
304 	}
305 }
306 
307 /*
308  * Set interrupt number "irq" in the GPIO as a wake-up source.
309  * While system is running, all registered GPIO interrupts need to have
310  * wake-up enabled. When system is suspended, only selected GPIO interrupts
311  * need to have wake-up enabled.
312  * @param  irq          interrupt source number
313  * @param  enable       enable as wake-up if equal to non-zero
314  * @return       This function returns 0 on success.
315  */
316 static int gpio_set_wake_irq(struct irq_data *d, u32 enable)
317 {
318 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
319 	struct mxc_gpio_port *port = gc->private;
320 	u32 gpio_idx = d->hwirq;
321 
322 	if (enable) {
323 		if (port->irq_high && (gpio_idx >= 16))
324 			enable_irq_wake(port->irq_high);
325 		else
326 			enable_irq_wake(port->irq);
327 	} else {
328 		if (port->irq_high && (gpio_idx >= 16))
329 			disable_irq_wake(port->irq_high);
330 		else
331 			disable_irq_wake(port->irq);
332 	}
333 
334 	return 0;
335 }
336 
337 static void __init mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base)
338 {
339 	struct irq_chip_generic *gc;
340 	struct irq_chip_type *ct;
341 
342 	gc = irq_alloc_generic_chip("gpio-mxc", 1, irq_base,
343 				    port->base, handle_level_irq);
344 	gc->private = port;
345 
346 	ct = gc->chip_types;
347 	ct->chip.irq_ack = irq_gc_ack_set_bit;
348 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
349 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
350 	ct->chip.irq_set_type = gpio_set_irq_type;
351 	ct->chip.irq_set_wake = gpio_set_wake_irq;
352 	ct->regs.ack = GPIO_ISR;
353 	ct->regs.mask = GPIO_IMR;
354 
355 	irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_NESTED_LOCK,
356 			       IRQ_NOREQUEST, 0);
357 }
358 
359 static void __devinit mxc_gpio_get_hw(struct platform_device *pdev)
360 {
361 	const struct of_device_id *of_id =
362 			of_match_device(mxc_gpio_dt_ids, &pdev->dev);
363 	enum mxc_gpio_hwtype hwtype;
364 
365 	if (of_id)
366 		pdev->id_entry = of_id->data;
367 	hwtype = pdev->id_entry->driver_data;
368 
369 	if (mxc_gpio_hwtype) {
370 		/*
371 		 * The driver works with a reasonable presupposition,
372 		 * that is all gpio ports must be the same type when
373 		 * running on one soc.
374 		 */
375 		BUG_ON(mxc_gpio_hwtype != hwtype);
376 		return;
377 	}
378 
379 	if (hwtype == IMX35_GPIO)
380 		mxc_gpio_hwdata = &imx35_gpio_hwdata;
381 	else if (hwtype == IMX31_GPIO)
382 		mxc_gpio_hwdata = &imx31_gpio_hwdata;
383 	else
384 		mxc_gpio_hwdata = &imx1_imx21_gpio_hwdata;
385 
386 	mxc_gpio_hwtype = hwtype;
387 }
388 
389 static int mxc_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
390 {
391 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
392 	struct mxc_gpio_port *port =
393 		container_of(bgc, struct mxc_gpio_port, bgc);
394 
395 	return irq_find_mapping(port->domain, offset);
396 }
397 
398 static int __devinit mxc_gpio_probe(struct platform_device *pdev)
399 {
400 	struct device_node *np = pdev->dev.of_node;
401 	struct mxc_gpio_port *port;
402 	struct resource *iores;
403 	int irq_base;
404 	int err;
405 
406 	mxc_gpio_get_hw(pdev);
407 
408 	port = kzalloc(sizeof(struct mxc_gpio_port), GFP_KERNEL);
409 	if (!port)
410 		return -ENOMEM;
411 
412 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
413 	if (!iores) {
414 		err = -ENODEV;
415 		goto out_kfree;
416 	}
417 
418 	if (!request_mem_region(iores->start, resource_size(iores),
419 				pdev->name)) {
420 		err = -EBUSY;
421 		goto out_kfree;
422 	}
423 
424 	port->base = ioremap(iores->start, resource_size(iores));
425 	if (!port->base) {
426 		err = -ENOMEM;
427 		goto out_release_mem;
428 	}
429 
430 	port->irq_high = platform_get_irq(pdev, 1);
431 	port->irq = platform_get_irq(pdev, 0);
432 	if (port->irq < 0) {
433 		err = -EINVAL;
434 		goto out_iounmap;
435 	}
436 
437 	/* disable the interrupt and clear the status */
438 	writel(0, port->base + GPIO_IMR);
439 	writel(~0, port->base + GPIO_ISR);
440 
441 	if (mxc_gpio_hwtype == IMX21_GPIO) {
442 		/*
443 		 * Setup one handler for all GPIO interrupts. Actually setting
444 		 * the handler is needed only once, but doing it for every port
445 		 * is more robust and easier.
446 		 */
447 		irq_set_chained_handler(port->irq, mx2_gpio_irq_handler);
448 	} else {
449 		/* setup one handler for each entry */
450 		irq_set_chained_handler(port->irq, mx3_gpio_irq_handler);
451 		irq_set_handler_data(port->irq, port);
452 		if (port->irq_high > 0) {
453 			/* setup handler for GPIO 16 to 31 */
454 			irq_set_chained_handler(port->irq_high,
455 						mx3_gpio_irq_handler);
456 			irq_set_handler_data(port->irq_high, port);
457 		}
458 	}
459 
460 	err = bgpio_init(&port->bgc, &pdev->dev, 4,
461 			 port->base + GPIO_PSR,
462 			 port->base + GPIO_DR, NULL,
463 			 port->base + GPIO_GDIR, NULL, 0);
464 	if (err)
465 		goto out_iounmap;
466 
467 	port->bgc.gc.to_irq = mxc_gpio_to_irq;
468 	port->bgc.gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 :
469 					     pdev->id * 32;
470 
471 	err = gpiochip_add(&port->bgc.gc);
472 	if (err)
473 		goto out_bgpio_remove;
474 
475 	irq_base = irq_alloc_descs(-1, 0, 32, numa_node_id());
476 	if (irq_base < 0) {
477 		err = irq_base;
478 		goto out_gpiochip_remove;
479 	}
480 
481 	port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
482 					     &irq_domain_simple_ops, NULL);
483 	if (!port->domain) {
484 		err = -ENODEV;
485 		goto out_irqdesc_free;
486 	}
487 
488 	/* gpio-mxc can be a generic irq chip */
489 	mxc_gpio_init_gc(port, irq_base);
490 
491 	list_add_tail(&port->node, &mxc_gpio_ports);
492 
493 	return 0;
494 
495 out_irqdesc_free:
496 	irq_free_descs(irq_base, 32);
497 out_gpiochip_remove:
498 	WARN_ON(gpiochip_remove(&port->bgc.gc) < 0);
499 out_bgpio_remove:
500 	bgpio_remove(&port->bgc);
501 out_iounmap:
502 	iounmap(port->base);
503 out_release_mem:
504 	release_mem_region(iores->start, resource_size(iores));
505 out_kfree:
506 	kfree(port);
507 	dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err);
508 	return err;
509 }
510 
511 static struct platform_driver mxc_gpio_driver = {
512 	.driver		= {
513 		.name	= "gpio-mxc",
514 		.owner	= THIS_MODULE,
515 		.of_match_table = mxc_gpio_dt_ids,
516 	},
517 	.probe		= mxc_gpio_probe,
518 	.id_table	= mxc_gpio_devtype,
519 };
520 
521 static int __init gpio_mxc_init(void)
522 {
523 	return platform_driver_register(&mxc_gpio_driver);
524 }
525 postcore_initcall(gpio_mxc_init);
526 
527 MODULE_AUTHOR("Freescale Semiconductor, "
528 	      "Daniel Mack <danielncaiaq.de>, "
529 	      "Juergen Beisert <kernel@pengutronix.de>");
530 MODULE_DESCRIPTION("Freescale MXC GPIO");
531 MODULE_LICENSE("GPL");
532