tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * timbgpio.c timberdale FPGA GPIO driver
3 * Copyright (c) 2009 Intel Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19/* Supports:
20 * Timberdale FPGA GPIO
21 */
22
23#include <linux/module.h>
24#include <linux/gpio.h>
25#include <linux/platform_device.h>
26#include <linux/irq.h>
27#include <linux/io.h>
28#include <linux/timb_gpio.h>
29#include <linux/interrupt.h>
30#include <linux/slab.h>
31
32#define DRIVER_NAME "timb-gpio"
33
34#define TGPIOVAL 0x00
35#define TGPIODIR 0x04
36#define TGPIO_IER 0x08
37#define TGPIO_ISR 0x0c
38#define TGPIO_IPR 0x10
39#define TGPIO_ICR 0x14
40#define TGPIO_FLR 0x18
41#define TGPIO_LVR 0x1c
42#define TGPIO_VER 0x20
43#define TGPIO_BFLR 0x24
44
45struct timbgpio {
46 void __iomem *membase;
47 spinlock_t lock; /* mutual exclusion */
48 struct gpio_chip gpio;
49 int irq_base;
50 unsigned long last_ier;
51};
52
53static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
54 unsigned offset, bool enabled)
55{
56 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
57 u32 reg;
58
59 spin_lock(&tgpio->lock);
60 reg = ioread32(tgpio->membase + offset);
61
62 if (enabled)
63 reg |= (1 << index);
64 else
65 reg &= ~(1 << index);
66
67 iowrite32(reg, tgpio->membase + offset);
68 spin_unlock(&tgpio->lock);
69
70 return 0;
71}
72
73static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
74{
75 return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
76}
77
78static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
79{
80 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
81 u32 value;
82
83 value = ioread32(tgpio->membase + TGPIOVAL);
84 return (value & (1 << nr)) ? 1 : 0;
85}
86
87static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
88 unsigned nr, int val)
89{
90 return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
91}
92
93static void timbgpio_gpio_set(struct gpio_chip *gpio,
94 unsigned nr, int val)
95{
96 timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
97}
98
99static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
100{
101 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
102
103 if (tgpio->irq_base <= 0)
104 return -EINVAL;
105
106 return tgpio->irq_base + offset;
107}
108
109/*
110 * GPIO IRQ
111 */
112static void timbgpio_irq_disable(unsigned irq)
113{
114 struct timbgpio *tgpio = get_irq_chip_data(irq);
115 int offset = irq - tgpio->irq_base;
116 unsigned long flags;
117
118 spin_lock_irqsave(&tgpio->lock, flags);
119 tgpio->last_ier &= ~(1 << offset);
120 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
121 spin_unlock_irqrestore(&tgpio->lock, flags);
122}
123
124static void timbgpio_irq_enable(unsigned irq)
125{
126 struct timbgpio *tgpio = get_irq_chip_data(irq);
127 int offset = irq - tgpio->irq_base;
128 unsigned long flags;
129
130 spin_lock_irqsave(&tgpio->lock, flags);
131 tgpio->last_ier |= 1 << offset;
132 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
133 spin_unlock_irqrestore(&tgpio->lock, flags);
134}
135
136static int timbgpio_irq_type(unsigned irq, unsigned trigger)
137{
138 struct timbgpio *tgpio = get_irq_chip_data(irq);
139 int offset = irq - tgpio->irq_base;
140 unsigned long flags;
141 u32 lvr, flr, bflr = 0;
142 u32 ver;
143 int ret = 0;
144
145 if (offset < 0 || offset > tgpio->gpio.ngpio)
146 return -EINVAL;
147
148 ver = ioread32(tgpio->membase + TGPIO_VER);
149
150 spin_lock_irqsave(&tgpio->lock, flags);
151
152 lvr = ioread32(tgpio->membase + TGPIO_LVR);
153 flr = ioread32(tgpio->membase + TGPIO_FLR);
154 if (ver > 2)
155 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
156
157 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
158 bflr &= ~(1 << offset);
159 flr &= ~(1 << offset);
160 if (trigger & IRQ_TYPE_LEVEL_HIGH)
161 lvr |= 1 << offset;
162 else
163 lvr &= ~(1 << offset);
164 }
165
166 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
167 if (ver < 3) {
168 ret = -EINVAL;
169 goto out;
170 }
171 else {
172 flr |= 1 << offset;
173 bflr |= 1 << offset;
174 }
175 } else {
176 bflr &= ~(1 << offset);
177 flr |= 1 << offset;
178 if (trigger & IRQ_TYPE_EDGE_FALLING)
179 lvr &= ~(1 << offset);
180 else
181 lvr |= 1 << offset;
182 }
183
184 iowrite32(lvr, tgpio->membase + TGPIO_LVR);
185 iowrite32(flr, tgpio->membase + TGPIO_FLR);
186 if (ver > 2)
187 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
188
189 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
190
191out:
192 spin_unlock_irqrestore(&tgpio->lock, flags);
193 return ret;
194}
195
196static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
197{
198 struct timbgpio *tgpio = get_irq_data(irq);
199 unsigned long ipr;
200 int offset;
201
202 desc->chip->ack(irq);
203 ipr = ioread32(tgpio->membase + TGPIO_IPR);
204 iowrite32(ipr, tgpio->membase + TGPIO_ICR);
205
206 /*
207 * Some versions of the hardware trash the IER register if more than
208 * one interrupt is received simultaneously.
209 */
210 iowrite32(0, tgpio->membase + TGPIO_IER);
211
212 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
213 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
214
215 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
216}
217
218static struct irq_chip timbgpio_irqchip = {
219 .name = "GPIO",
220 .enable = timbgpio_irq_enable,
221 .disable = timbgpio_irq_disable,
222 .set_type = timbgpio_irq_type,
223};
224
225static int __devinit timbgpio_probe(struct platform_device *pdev)
226{
227 int err, i;
228 struct gpio_chip *gc;
229 struct timbgpio *tgpio;
230 struct resource *iomem;
231 struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
232 int irq = platform_get_irq(pdev, 0);
233
234 if (!pdata || pdata->nr_pins > 32) {
235 err = -EINVAL;
236 goto err_mem;
237 }
238
239 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
240 if (!iomem) {
241 err = -EINVAL;
242 goto err_mem;
243 }
244
245 tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL);
246 if (!tgpio) {
247 err = -EINVAL;
248 goto err_mem;
249 }
250 tgpio->irq_base = pdata->irq_base;
251
252 spin_lock_init(&tgpio->lock);
253
254 if (!request_mem_region(iomem->start, resource_size(iomem),
255 DRIVER_NAME)) {
256 err = -EBUSY;
257 goto err_request;
258 }
259
260 tgpio->membase = ioremap(iomem->start, resource_size(iomem));
261 if (!tgpio->membase) {
262 err = -ENOMEM;
263 goto err_ioremap;
264 }
265
266 gc = &tgpio->gpio;
267
268 gc->label = dev_name(&pdev->dev);
269 gc->owner = THIS_MODULE;
270 gc->dev = &pdev->dev;
271 gc->direction_input = timbgpio_gpio_direction_input;
272 gc->get = timbgpio_gpio_get;
273 gc->direction_output = timbgpio_gpio_direction_output;
274 gc->set = timbgpio_gpio_set;
275 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
276 gc->dbg_show = NULL;
277 gc->base = pdata->gpio_base;
278 gc->ngpio = pdata->nr_pins;
279 gc->can_sleep = 0;
280
281 err = gpiochip_add(gc);
282 if (err)
283 goto err_chipadd;
284
285 platform_set_drvdata(pdev, tgpio);
286
287 /* make sure to disable interrupts */
288 iowrite32(0x0, tgpio->membase + TGPIO_IER);
289
290 if (irq < 0 || tgpio->irq_base <= 0)
291 return 0;
292
293 for (i = 0; i < pdata->nr_pins; i++) {
294 set_irq_chip_and_handler_name(tgpio->irq_base + i,
295 &timbgpio_irqchip, handle_simple_irq, "mux");
296 set_irq_chip_data(tgpio->irq_base + i, tgpio);
297#ifdef CONFIG_ARM
298 set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
299#endif
300 }
301
302 set_irq_data(irq, tgpio);
303 set_irq_chained_handler(irq, timbgpio_irq);
304
305 return 0;
306
307err_chipadd:
308 iounmap(tgpio->membase);
309err_ioremap:
310 release_mem_region(iomem->start, resource_size(iomem));
311err_request:
312 kfree(tgpio);
313err_mem:
314 printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err);
315
316 return err;
317}
318
319static int __devexit timbgpio_remove(struct platform_device *pdev)
320{
321 int err;
322 struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
323 struct timbgpio *tgpio = platform_get_drvdata(pdev);
324 struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
325 int irq = platform_get_irq(pdev, 0);
326
327 if (irq >= 0 && tgpio->irq_base > 0) {
328 int i;
329 for (i = 0; i < pdata->nr_pins; i++) {
330 set_irq_chip(tgpio->irq_base + i, NULL);
331 set_irq_chip_data(tgpio->irq_base + i, NULL);
332 }
333
334 set_irq_handler(irq, NULL);
335 set_irq_data(irq, NULL);
336 }
337
338 err = gpiochip_remove(&tgpio->gpio);
339 if (err)
340 printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");
341
342 iounmap(tgpio->membase);
343 release_mem_region(iomem->start, resource_size(iomem));
344 kfree(tgpio);
345
346 platform_set_drvdata(pdev, NULL);
347
348 return 0;
349}
350
351static struct platform_driver timbgpio_platform_driver = {
352 .driver = {
353 .name = DRIVER_NAME,
354 .owner = THIS_MODULE,
355 },
356 .probe = timbgpio_probe,
357 .remove = timbgpio_remove,
358};
359
360/*--------------------------------------------------------------------------*/
361
362static int __init timbgpio_init(void)
363{
364 return platform_driver_register(&timbgpio_platform_driver);
365}
366
367static void __exit timbgpio_exit(void)
368{
369 platform_driver_unregister(&timbgpio_platform_driver);
370}
371
372module_init(timbgpio_init);
373module_exit(timbgpio_exit);
374
375MODULE_DESCRIPTION("Timberdale GPIO driver");
376MODULE_LICENSE("GPL v2");
377MODULE_AUTHOR("Mocean Laboratories");
378MODULE_ALIAS("platform:"DRIVER_NAME);
379