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35570ac6 RR |
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/io.h> | |
27 | #include <linux/timb_gpio.h> | |
28 | #include <linux/interrupt.h> | |
29 | ||
30 | #define DRIVER_NAME "timb-gpio" | |
31 | ||
32 | #define TGPIOVAL 0x00 | |
33 | #define TGPIODIR 0x04 | |
34 | #define TGPIO_IER 0x08 | |
35 | #define TGPIO_ISR 0x0c | |
36 | #define TGPIO_IPR 0x10 | |
37 | #define TGPIO_ICR 0x14 | |
38 | #define TGPIO_FLR 0x18 | |
39 | #define TGPIO_LVR 0x1c | |
40 | ||
41 | struct timbgpio { | |
42 | void __iomem *membase; | |
43 | spinlock_t lock; /* mutual exclusion */ | |
44 | struct gpio_chip gpio; | |
45 | int irq_base; | |
46 | }; | |
47 | ||
48 | static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index, | |
49 | unsigned offset, bool enabled) | |
50 | { | |
51 | struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); | |
52 | u32 reg; | |
53 | ||
54 | spin_lock(&tgpio->lock); | |
55 | reg = ioread32(tgpio->membase + offset); | |
56 | ||
57 | if (enabled) | |
58 | reg |= (1 << index); | |
59 | else | |
60 | reg &= ~(1 << index); | |
61 | ||
62 | iowrite32(reg, tgpio->membase + offset); | |
63 | spin_unlock(&tgpio->lock); | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
68 | static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) | |
69 | { | |
70 | return timbgpio_update_bit(gpio, nr, TGPIODIR, true); | |
71 | } | |
72 | ||
73 | static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr) | |
74 | { | |
75 | struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); | |
76 | u32 value; | |
77 | ||
78 | value = ioread32(tgpio->membase + TGPIOVAL); | |
79 | return (value & (1 << nr)) ? 1 : 0; | |
80 | } | |
81 | ||
82 | static int timbgpio_gpio_direction_output(struct gpio_chip *gpio, | |
83 | unsigned nr, int val) | |
84 | { | |
85 | return timbgpio_update_bit(gpio, nr, TGPIODIR, false); | |
86 | } | |
87 | ||
88 | static void timbgpio_gpio_set(struct gpio_chip *gpio, | |
89 | unsigned nr, int val) | |
90 | { | |
91 | timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0); | |
92 | } | |
93 | ||
94 | static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset) | |
95 | { | |
96 | struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio); | |
97 | ||
98 | if (tgpio->irq_base <= 0) | |
99 | return -EINVAL; | |
100 | ||
101 | return tgpio->irq_base + offset; | |
102 | } | |
103 | ||
104 | /* | |
105 | * GPIO IRQ | |
106 | */ | |
107 | static void timbgpio_irq_disable(unsigned irq) | |
108 | { | |
109 | struct timbgpio *tgpio = get_irq_chip_data(irq); | |
110 | int offset = irq - tgpio->irq_base; | |
111 | ||
112 | timbgpio_update_bit(&tgpio->gpio, offset, TGPIO_IER, 0); | |
113 | } | |
114 | ||
115 | static void timbgpio_irq_enable(unsigned irq) | |
116 | { | |
117 | struct timbgpio *tgpio = get_irq_chip_data(irq); | |
118 | int offset = irq - tgpio->irq_base; | |
119 | ||
120 | timbgpio_update_bit(&tgpio->gpio, offset, TGPIO_IER, 1); | |
121 | } | |
122 | ||
123 | static int timbgpio_irq_type(unsigned irq, unsigned trigger) | |
124 | { | |
125 | struct timbgpio *tgpio = get_irq_chip_data(irq); | |
126 | int offset = irq - tgpio->irq_base; | |
127 | unsigned long flags; | |
128 | u32 lvr, flr; | |
129 | ||
130 | if (offset < 0 || offset > tgpio->gpio.ngpio) | |
131 | return -EINVAL; | |
132 | ||
133 | spin_lock_irqsave(&tgpio->lock, flags); | |
134 | ||
135 | lvr = ioread32(tgpio->membase + TGPIO_LVR); | |
136 | flr = ioread32(tgpio->membase + TGPIO_FLR); | |
137 | ||
138 | if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { | |
139 | flr &= ~(1 << offset); | |
140 | if (trigger & IRQ_TYPE_LEVEL_HIGH) | |
141 | lvr |= 1 << offset; | |
142 | else | |
143 | lvr &= ~(1 << offset); | |
144 | } | |
145 | ||
146 | if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) | |
147 | return -EINVAL; | |
148 | else { | |
149 | flr |= 1 << offset; | |
150 | /* opposite compared to the datasheet, but it mirrors the | |
151 | * reality | |
152 | */ | |
153 | if (trigger & IRQ_TYPE_EDGE_FALLING) | |
154 | lvr |= 1 << offset; | |
155 | else | |
156 | lvr &= ~(1 << offset); | |
157 | } | |
158 | ||
159 | iowrite32(lvr, tgpio->membase + TGPIO_LVR); | |
160 | iowrite32(flr, tgpio->membase + TGPIO_FLR); | |
161 | iowrite32(1 << offset, tgpio->membase + TGPIO_ICR); | |
162 | spin_unlock_irqrestore(&tgpio->lock, flags); | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | static void timbgpio_irq(unsigned int irq, struct irq_desc *desc) | |
168 | { | |
169 | struct timbgpio *tgpio = get_irq_data(irq); | |
170 | unsigned long ipr; | |
171 | int offset; | |
172 | ||
173 | desc->chip->ack(irq); | |
174 | ipr = ioread32(tgpio->membase + TGPIO_IPR); | |
175 | iowrite32(ipr, tgpio->membase + TGPIO_ICR); | |
176 | ||
177 | for_each_bit(offset, &ipr, tgpio->gpio.ngpio) | |
178 | generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset)); | |
179 | } | |
180 | ||
181 | static struct irq_chip timbgpio_irqchip = { | |
182 | .name = "GPIO", | |
183 | .enable = timbgpio_irq_enable, | |
184 | .disable = timbgpio_irq_disable, | |
185 | .set_type = timbgpio_irq_type, | |
186 | }; | |
187 | ||
188 | static int __devinit timbgpio_probe(struct platform_device *pdev) | |
189 | { | |
190 | int err, i; | |
191 | struct gpio_chip *gc; | |
192 | struct timbgpio *tgpio; | |
193 | struct resource *iomem; | |
194 | struct timbgpio_platform_data *pdata = pdev->dev.platform_data; | |
195 | int irq = platform_get_irq(pdev, 0); | |
196 | ||
197 | if (!pdata || pdata->nr_pins > 32) { | |
198 | err = -EINVAL; | |
199 | goto err_mem; | |
200 | } | |
201 | ||
202 | iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
203 | if (!iomem) { | |
204 | err = -EINVAL; | |
205 | goto err_mem; | |
206 | } | |
207 | ||
208 | tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL); | |
209 | if (!tgpio) { | |
210 | err = -EINVAL; | |
211 | goto err_mem; | |
212 | } | |
213 | tgpio->irq_base = pdata->irq_base; | |
214 | ||
215 | spin_lock_init(&tgpio->lock); | |
216 | ||
217 | if (!request_mem_region(iomem->start, resource_size(iomem), | |
218 | DRIVER_NAME)) { | |
219 | err = -EBUSY; | |
220 | goto err_request; | |
221 | } | |
222 | ||
223 | tgpio->membase = ioremap(iomem->start, resource_size(iomem)); | |
224 | if (!tgpio->membase) { | |
225 | err = -ENOMEM; | |
226 | goto err_ioremap; | |
227 | } | |
228 | ||
229 | gc = &tgpio->gpio; | |
230 | ||
231 | gc->label = dev_name(&pdev->dev); | |
232 | gc->owner = THIS_MODULE; | |
233 | gc->dev = &pdev->dev; | |
234 | gc->direction_input = timbgpio_gpio_direction_input; | |
235 | gc->get = timbgpio_gpio_get; | |
236 | gc->direction_output = timbgpio_gpio_direction_output; | |
237 | gc->set = timbgpio_gpio_set; | |
238 | gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL; | |
239 | gc->dbg_show = NULL; | |
240 | gc->base = pdata->gpio_base; | |
241 | gc->ngpio = pdata->nr_pins; | |
242 | gc->can_sleep = 0; | |
243 | ||
244 | err = gpiochip_add(gc); | |
245 | if (err) | |
246 | goto err_chipadd; | |
247 | ||
248 | platform_set_drvdata(pdev, tgpio); | |
249 | ||
250 | /* make sure to disable interrupts */ | |
251 | iowrite32(0x0, tgpio->membase + TGPIO_IER); | |
252 | ||
253 | if (irq < 0 || tgpio->irq_base <= 0) | |
254 | return 0; | |
255 | ||
256 | for (i = 0; i < pdata->nr_pins; i++) { | |
257 | set_irq_chip_and_handler_name(tgpio->irq_base + i, | |
258 | &timbgpio_irqchip, handle_simple_irq, "mux"); | |
259 | set_irq_chip_data(tgpio->irq_base + i, tgpio); | |
260 | #ifdef CONFIG_ARM | |
261 | set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE); | |
262 | #endif | |
263 | } | |
264 | ||
265 | set_irq_data(irq, tgpio); | |
266 | set_irq_chained_handler(irq, timbgpio_irq); | |
267 | ||
268 | return 0; | |
269 | ||
270 | err_chipadd: | |
271 | iounmap(tgpio->membase); | |
272 | err_ioremap: | |
273 | release_mem_region(iomem->start, resource_size(iomem)); | |
274 | err_request: | |
275 | kfree(tgpio); | |
276 | err_mem: | |
277 | printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err); | |
278 | ||
279 | return err; | |
280 | } | |
281 | ||
282 | static int __devexit timbgpio_remove(struct platform_device *pdev) | |
283 | { | |
284 | int err; | |
285 | struct timbgpio_platform_data *pdata = pdev->dev.platform_data; | |
286 | struct timbgpio *tgpio = platform_get_drvdata(pdev); | |
287 | struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
288 | int irq = platform_get_irq(pdev, 0); | |
289 | ||
290 | if (irq >= 0 && tgpio->irq_base > 0) { | |
291 | int i; | |
292 | for (i = 0; i < pdata->nr_pins; i++) { | |
293 | set_irq_chip(tgpio->irq_base + i, NULL); | |
294 | set_irq_chip_data(tgpio->irq_base + i, NULL); | |
295 | } | |
296 | ||
297 | set_irq_handler(irq, NULL); | |
298 | set_irq_data(irq, NULL); | |
299 | } | |
300 | ||
301 | err = gpiochip_remove(&tgpio->gpio); | |
302 | if (err) | |
303 | printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n"); | |
304 | ||
305 | iounmap(tgpio->membase); | |
306 | release_mem_region(iomem->start, resource_size(iomem)); | |
307 | kfree(tgpio); | |
308 | ||
309 | platform_set_drvdata(pdev, NULL); | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
314 | static struct platform_driver timbgpio_platform_driver = { | |
315 | .driver = { | |
316 | .name = DRIVER_NAME, | |
317 | .owner = THIS_MODULE, | |
318 | }, | |
319 | .probe = timbgpio_probe, | |
320 | .remove = timbgpio_remove, | |
321 | }; | |
322 | ||
323 | /*--------------------------------------------------------------------------*/ | |
324 | ||
325 | static int __init timbgpio_init(void) | |
326 | { | |
327 | return platform_driver_register(&timbgpio_platform_driver); | |
328 | } | |
329 | ||
330 | static void __exit timbgpio_exit(void) | |
331 | { | |
332 | platform_driver_unregister(&timbgpio_platform_driver); | |
333 | } | |
334 | ||
335 | module_init(timbgpio_init); | |
336 | module_exit(timbgpio_exit); | |
337 | ||
338 | MODULE_DESCRIPTION("Timberdale GPIO driver"); | |
339 | MODULE_LICENSE("GPL v2"); | |
340 | MODULE_AUTHOR("Mocean Laboratories"); | |
341 | MODULE_ALIAS("platform:"DRIVER_NAME); | |
342 |