xref: /openbmc/linux/drivers/gpio/gpio-mxs.c (revision b96fc2f3)
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,
20  * MA  02110-1301, USA.
21  */
22 
23 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/irq.h>
28 #include <linux/irqdomain.h>
29 #include <linux/gpio.h>
30 #include <linux/of.h>
31 #include <linux/of_address.h>
32 #include <linux/of_device.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/basic_mmio_gpio.h>
36 #include <linux/module.h>
37 
38 #define MXS_SET		0x4
39 #define MXS_CLR		0x8
40 
41 #define PINCTRL_DOUT(p)		((is_imx23_gpio(p) ? 0x0500 : 0x0700) + (p->id) * 0x10)
42 #define PINCTRL_DIN(p)		((is_imx23_gpio(p) ? 0x0600 : 0x0900) + (p->id) * 0x10)
43 #define PINCTRL_DOE(p)		((is_imx23_gpio(p) ? 0x0700 : 0x0b00) + (p->id) * 0x10)
44 #define PINCTRL_PIN2IRQ(p)	((is_imx23_gpio(p) ? 0x0800 : 0x1000) + (p->id) * 0x10)
45 #define PINCTRL_IRQEN(p)	((is_imx23_gpio(p) ? 0x0900 : 0x1100) + (p->id) * 0x10)
46 #define PINCTRL_IRQLEV(p)	((is_imx23_gpio(p) ? 0x0a00 : 0x1200) + (p->id) * 0x10)
47 #define PINCTRL_IRQPOL(p)	((is_imx23_gpio(p) ? 0x0b00 : 0x1300) + (p->id) * 0x10)
48 #define PINCTRL_IRQSTAT(p)	((is_imx23_gpio(p) ? 0x0c00 : 0x1400) + (p->id) * 0x10)
49 
50 #define GPIO_INT_FALL_EDGE	0x0
51 #define GPIO_INT_LOW_LEV	0x1
52 #define GPIO_INT_RISE_EDGE	0x2
53 #define GPIO_INT_HIGH_LEV	0x3
54 #define GPIO_INT_LEV_MASK	(1 << 0)
55 #define GPIO_INT_POL_MASK	(1 << 1)
56 
57 enum mxs_gpio_id {
58 	IMX23_GPIO,
59 	IMX28_GPIO,
60 };
61 
62 struct mxs_gpio_port {
63 	void __iomem *base;
64 	int id;
65 	int irq;
66 	struct irq_domain *domain;
67 	struct bgpio_chip bgc;
68 	enum mxs_gpio_id devid;
69 	u32 both_edges;
70 };
71 
72 static inline int is_imx23_gpio(struct mxs_gpio_port *port)
73 {
74 	return port->devid == IMX23_GPIO;
75 }
76 
77 static inline int is_imx28_gpio(struct mxs_gpio_port *port)
78 {
79 	return port->devid == IMX28_GPIO;
80 }
81 
82 /* Note: This driver assumes 32 GPIOs are handled in one register */
83 
84 static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
85 {
86 	u32 val;
87 	u32 pin_mask = 1 << d->hwirq;
88 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
89 	struct mxs_gpio_port *port = gc->private;
90 	void __iomem *pin_addr;
91 	int edge;
92 
93 	port->both_edges &= ~pin_mask;
94 	switch (type) {
95 	case IRQ_TYPE_EDGE_BOTH:
96 		val = gpio_get_value(port->bgc.gc.base + d->hwirq);
97 		if (val)
98 			edge = GPIO_INT_FALL_EDGE;
99 		else
100 			edge = GPIO_INT_RISE_EDGE;
101 		port->both_edges |= pin_mask;
102 		break;
103 	case IRQ_TYPE_EDGE_RISING:
104 		edge = GPIO_INT_RISE_EDGE;
105 		break;
106 	case IRQ_TYPE_EDGE_FALLING:
107 		edge = GPIO_INT_FALL_EDGE;
108 		break;
109 	case IRQ_TYPE_LEVEL_LOW:
110 		edge = GPIO_INT_LOW_LEV;
111 		break;
112 	case IRQ_TYPE_LEVEL_HIGH:
113 		edge = GPIO_INT_HIGH_LEV;
114 		break;
115 	default:
116 		return -EINVAL;
117 	}
118 
119 	/* set level or edge */
120 	pin_addr = port->base + PINCTRL_IRQLEV(port);
121 	if (edge & GPIO_INT_LEV_MASK)
122 		writel(pin_mask, pin_addr + MXS_SET);
123 	else
124 		writel(pin_mask, pin_addr + MXS_CLR);
125 
126 	/* set polarity */
127 	pin_addr = port->base + PINCTRL_IRQPOL(port);
128 	if (edge & GPIO_INT_POL_MASK)
129 		writel(pin_mask, pin_addr + MXS_SET);
130 	else
131 		writel(pin_mask, pin_addr + MXS_CLR);
132 
133 	writel(pin_mask,
134 	       port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
135 
136 	return 0;
137 }
138 
139 static void mxs_flip_edge(struct mxs_gpio_port *port, u32 gpio)
140 {
141 	u32 bit, val, edge;
142 	void __iomem *pin_addr;
143 
144 	bit = 1 << gpio;
145 
146 	pin_addr = port->base + PINCTRL_IRQPOL(port);
147 	val = readl(pin_addr);
148 	edge = val & bit;
149 
150 	if (edge)
151 		writel(bit, pin_addr + MXS_CLR);
152 	else
153 		writel(bit, pin_addr + MXS_SET);
154 }
155 
156 /* MXS has one interrupt *per* gpio port */
157 static void mxs_gpio_irq_handler(struct irq_desc *desc)
158 {
159 	u32 irq_stat;
160 	struct mxs_gpio_port *port = irq_desc_get_handler_data(desc);
161 
162 	desc->irq_data.chip->irq_ack(&desc->irq_data);
163 
164 	irq_stat = readl(port->base + PINCTRL_IRQSTAT(port)) &
165 			readl(port->base + PINCTRL_IRQEN(port));
166 
167 	while (irq_stat != 0) {
168 		int irqoffset = fls(irq_stat) - 1;
169 		if (port->both_edges & (1 << irqoffset))
170 			mxs_flip_edge(port, irqoffset);
171 
172 		generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
173 		irq_stat &= ~(1 << irqoffset);
174 	}
175 }
176 
177 /*
178  * Set interrupt number "irq" in the GPIO as a wake-up source.
179  * While system is running, all registered GPIO interrupts need to have
180  * wake-up enabled. When system is suspended, only selected GPIO interrupts
181  * need to have wake-up enabled.
182  * @param  irq          interrupt source number
183  * @param  enable       enable as wake-up if equal to non-zero
184  * @return       This function returns 0 on success.
185  */
186 static int mxs_gpio_set_wake_irq(struct irq_data *d, unsigned int enable)
187 {
188 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
189 	struct mxs_gpio_port *port = gc->private;
190 
191 	if (enable)
192 		enable_irq_wake(port->irq);
193 	else
194 		disable_irq_wake(port->irq);
195 
196 	return 0;
197 }
198 
199 static int __init mxs_gpio_init_gc(struct mxs_gpio_port *port, int irq_base)
200 {
201 	struct irq_chip_generic *gc;
202 	struct irq_chip_type *ct;
203 
204 	gc = irq_alloc_generic_chip("gpio-mxs", 1, irq_base,
205 				    port->base, handle_level_irq);
206 	if (!gc)
207 		return -ENOMEM;
208 
209 	gc->private = port;
210 
211 	ct = gc->chip_types;
212 	ct->chip.irq_ack = irq_gc_ack_set_bit;
213 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
214 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
215 	ct->chip.irq_set_type = mxs_gpio_set_irq_type;
216 	ct->chip.irq_set_wake = mxs_gpio_set_wake_irq;
217 	ct->regs.ack = PINCTRL_IRQSTAT(port) + MXS_CLR;
218 	ct->regs.mask = PINCTRL_IRQEN(port);
219 
220 	irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_NESTED_LOCK,
221 			       IRQ_NOREQUEST, 0);
222 
223 	return 0;
224 }
225 
226 static int mxs_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
227 {
228 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
229 	struct mxs_gpio_port *port =
230 		container_of(bgc, struct mxs_gpio_port, bgc);
231 
232 	return irq_find_mapping(port->domain, offset);
233 }
234 
235 static int mxs_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
236 {
237 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
238 	struct mxs_gpio_port *port =
239 		container_of(bgc, struct mxs_gpio_port, bgc);
240 	u32 mask = 1 << offset;
241 	u32 dir;
242 
243 	dir = readl(port->base + PINCTRL_DOE(port));
244 	return !(dir & mask);
245 }
246 
247 static const struct platform_device_id mxs_gpio_ids[] = {
248 	{
249 		.name = "imx23-gpio",
250 		.driver_data = IMX23_GPIO,
251 	}, {
252 		.name = "imx28-gpio",
253 		.driver_data = IMX28_GPIO,
254 	}, {
255 		/* sentinel */
256 	}
257 };
258 MODULE_DEVICE_TABLE(platform, mxs_gpio_ids);
259 
260 static const struct of_device_id mxs_gpio_dt_ids[] = {
261 	{ .compatible = "fsl,imx23-gpio", .data = (void *) IMX23_GPIO, },
262 	{ .compatible = "fsl,imx28-gpio", .data = (void *) IMX28_GPIO, },
263 	{ /* sentinel */ }
264 };
265 MODULE_DEVICE_TABLE(of, mxs_gpio_dt_ids);
266 
267 static int mxs_gpio_probe(struct platform_device *pdev)
268 {
269 	const struct of_device_id *of_id =
270 			of_match_device(mxs_gpio_dt_ids, &pdev->dev);
271 	struct device_node *np = pdev->dev.of_node;
272 	struct device_node *parent;
273 	static void __iomem *base;
274 	struct mxs_gpio_port *port;
275 	int irq_base;
276 	int err;
277 
278 	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
279 	if (!port)
280 		return -ENOMEM;
281 
282 	port->id = of_alias_get_id(np, "gpio");
283 	if (port->id < 0)
284 		return port->id;
285 	port->devid = (enum mxs_gpio_id) of_id->data;
286 	port->irq = platform_get_irq(pdev, 0);
287 	if (port->irq < 0)
288 		return port->irq;
289 
290 	/*
291 	 * map memory region only once, as all the gpio ports
292 	 * share the same one
293 	 */
294 	if (!base) {
295 		parent = of_get_parent(np);
296 		base = of_iomap(parent, 0);
297 		of_node_put(parent);
298 		if (!base)
299 			return -EADDRNOTAVAIL;
300 	}
301 	port->base = base;
302 
303 	/*
304 	 * select the pin interrupt functionality but initially
305 	 * disable the interrupts
306 	 */
307 	writel(~0U, port->base + PINCTRL_PIN2IRQ(port));
308 	writel(0, port->base + PINCTRL_IRQEN(port));
309 
310 	/* clear address has to be used to clear IRQSTAT bits */
311 	writel(~0U, port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
312 
313 	irq_base = irq_alloc_descs(-1, 0, 32, numa_node_id());
314 	if (irq_base < 0)
315 		return irq_base;
316 
317 	port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
318 					     &irq_domain_simple_ops, NULL);
319 	if (!port->domain) {
320 		err = -ENODEV;
321 		goto out_irqdesc_free;
322 	}
323 
324 	/* gpio-mxs can be a generic irq chip */
325 	err = mxs_gpio_init_gc(port, irq_base);
326 	if (err < 0)
327 		goto out_irqdomain_remove;
328 
329 	/* setup one handler for each entry */
330 	irq_set_chained_handler_and_data(port->irq, mxs_gpio_irq_handler,
331 					 port);
332 
333 	err = bgpio_init(&port->bgc, &pdev->dev, 4,
334 			 port->base + PINCTRL_DIN(port),
335 			 port->base + PINCTRL_DOUT(port) + MXS_SET,
336 			 port->base + PINCTRL_DOUT(port) + MXS_CLR,
337 			 port->base + PINCTRL_DOE(port), NULL, 0);
338 	if (err)
339 		goto out_irqdesc_free;
340 
341 	port->bgc.gc.to_irq = mxs_gpio_to_irq;
342 	port->bgc.gc.get_direction = mxs_gpio_get_direction;
343 	port->bgc.gc.base = port->id * 32;
344 
345 	err = gpiochip_add(&port->bgc.gc);
346 	if (err)
347 		goto out_bgpio_remove;
348 
349 	return 0;
350 
351 out_bgpio_remove:
352 	bgpio_remove(&port->bgc);
353 out_irqdomain_remove:
354 	irq_domain_remove(port->domain);
355 out_irqdesc_free:
356 	irq_free_descs(irq_base, 32);
357 	return err;
358 }
359 
360 static struct platform_driver mxs_gpio_driver = {
361 	.driver		= {
362 		.name	= "gpio-mxs",
363 		.of_match_table = mxs_gpio_dt_ids,
364 	},
365 	.probe		= mxs_gpio_probe,
366 	.id_table	= mxs_gpio_ids,
367 };
368 
369 static int __init mxs_gpio_init(void)
370 {
371 	return platform_driver_register(&mxs_gpio_driver);
372 }
373 postcore_initcall(mxs_gpio_init);
374 
375 MODULE_AUTHOR("Freescale Semiconductor, "
376 	      "Daniel Mack <danielncaiaq.de>, "
377 	      "Juergen Beisert <kernel@pengutronix.de>");
378 MODULE_DESCRIPTION("Freescale MXS GPIO");
379 MODULE_LICENSE("GPL");
380