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
57enum mxs_gpio_id {
58	IMX23_GPIO,
59	IMX28_GPIO,
60};
61
62struct 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
72static inline int is_imx23_gpio(struct mxs_gpio_port *port)
73{
74	return port->devid == IMX23_GPIO;
75}
76
77static 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
84static 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
139static 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 */
157static 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 */
186static 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
199static 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
226static 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
235static 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
247static 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};
258MODULE_DEVICE_TABLE(platform, mxs_gpio_ids);
259
260static 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};
265MODULE_DEVICE_TABLE(of, mxs_gpio_dt_ids);
266
267static 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
351out_bgpio_remove:
352	bgpio_remove(&port->bgc);
353out_irqdomain_remove:
354	irq_domain_remove(port->domain);
355out_irqdesc_free:
356	irq_free_descs(irq_base, 32);
357	return err;
358}
359
360static 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
369static int __init mxs_gpio_init(void)
370{
371	return platform_driver_register(&mxs_gpio_driver);
372}
373postcore_initcall(mxs_gpio_init);
374
375MODULE_AUTHOR("Freescale Semiconductor, "
376	      "Daniel Mack <danielncaiaq.de>, "
377	      "Juergen Beisert <kernel@pengutronix.de>");
378MODULE_DESCRIPTION("Freescale MXS GPIO");
379MODULE_LICENSE("GPL");
380