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c5abbba9 THL |
1 | /* |
2 | * Copyright (C) 2013 Altera Corporation | |
3 | * Based on gpio-mpc8xxx.c | |
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 as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | ||
19 | #include <linux/io.h> | |
20 | #include <linux/of_gpio.h> | |
21 | #include <linux/platform_device.h> | |
22 | ||
23 | #define ALTERA_GPIO_MAX_NGPIO 32 | |
24 | #define ALTERA_GPIO_DATA 0x0 | |
25 | #define ALTERA_GPIO_DIR 0x4 | |
26 | #define ALTERA_GPIO_IRQ_MASK 0x8 | |
27 | #define ALTERA_GPIO_EDGE_CAP 0xc | |
28 | ||
29 | /** | |
30 | * struct altera_gpio_chip | |
31 | * @mmchip : memory mapped chip structure. | |
32 | * @gpio_lock : synchronization lock so that new irq/set/get requests | |
33 | will be blocked until the current one completes. | |
34 | * @interrupt_trigger : specifies the hardware configured IRQ trigger type | |
35 | (rising, falling, both, high) | |
36 | * @mapped_irq : kernel mapped irq number. | |
37 | */ | |
38 | struct altera_gpio_chip { | |
39 | struct of_mm_gpio_chip mmchip; | |
40 | spinlock_t gpio_lock; | |
41 | int interrupt_trigger; | |
42 | int mapped_irq; | |
43 | }; | |
44 | ||
45 | static void altera_gpio_irq_unmask(struct irq_data *d) | |
46 | { | |
47 | struct altera_gpio_chip *altera_gc; | |
48 | struct of_mm_gpio_chip *mm_gc; | |
49 | unsigned long flags; | |
50 | u32 intmask; | |
51 | ||
52 | altera_gc = irq_data_get_irq_chip_data(d); | |
53 | mm_gc = &altera_gc->mmchip; | |
54 | ||
55 | spin_lock_irqsave(&altera_gc->gpio_lock, flags); | |
56 | intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK); | |
57 | /* Set ALTERA_GPIO_IRQ_MASK bit to unmask */ | |
58 | intmask |= BIT(irqd_to_hwirq(d)); | |
59 | writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK); | |
60 | spin_unlock_irqrestore(&altera_gc->gpio_lock, flags); | |
61 | } | |
62 | ||
63 | static void altera_gpio_irq_mask(struct irq_data *d) | |
64 | { | |
65 | struct altera_gpio_chip *altera_gc; | |
66 | struct of_mm_gpio_chip *mm_gc; | |
67 | unsigned long flags; | |
68 | u32 intmask; | |
69 | ||
70 | altera_gc = irq_data_get_irq_chip_data(d); | |
71 | mm_gc = &altera_gc->mmchip; | |
72 | ||
73 | spin_lock_irqsave(&altera_gc->gpio_lock, flags); | |
74 | intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK); | |
75 | /* Clear ALTERA_GPIO_IRQ_MASK bit to mask */ | |
76 | intmask &= ~BIT(irqd_to_hwirq(d)); | |
77 | writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK); | |
78 | spin_unlock_irqrestore(&altera_gc->gpio_lock, flags); | |
79 | } | |
80 | ||
81 | /** | |
82 | * This controller's IRQ type is synthesized in hardware, so this function | |
83 | * just checks if the requested set_type matches the synthesized IRQ type | |
84 | */ | |
85 | static int altera_gpio_irq_set_type(struct irq_data *d, | |
86 | unsigned int type) | |
87 | { | |
88 | struct altera_gpio_chip *altera_gc; | |
89 | ||
90 | altera_gc = irq_data_get_irq_chip_data(d); | |
91 | ||
92 | if (type == IRQ_TYPE_NONE) | |
93 | return 0; | |
94 | if (type == IRQ_TYPE_LEVEL_HIGH && | |
95 | altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH) | |
96 | return 0; | |
97 | if (type == IRQ_TYPE_EDGE_RISING && | |
98 | altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_RISING) | |
99 | return 0; | |
100 | if (type == IRQ_TYPE_EDGE_FALLING && | |
101 | altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_FALLING) | |
102 | return 0; | |
103 | if (type == IRQ_TYPE_EDGE_BOTH && | |
104 | altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_BOTH) | |
105 | return 0; | |
106 | ||
107 | return -EINVAL; | |
108 | } | |
109 | ||
38e003f4 DL |
110 | static unsigned int altera_gpio_irq_startup(struct irq_data *d) |
111 | { | |
c5abbba9 THL |
112 | altera_gpio_irq_unmask(d); |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | static struct irq_chip altera_irq_chip = { | |
118 | .name = "altera-gpio", | |
119 | .irq_mask = altera_gpio_irq_mask, | |
120 | .irq_unmask = altera_gpio_irq_unmask, | |
121 | .irq_set_type = altera_gpio_irq_set_type, | |
122 | .irq_startup = altera_gpio_irq_startup, | |
123 | .irq_shutdown = altera_gpio_irq_mask, | |
124 | }; | |
125 | ||
126 | static int altera_gpio_get(struct gpio_chip *gc, unsigned offset) | |
127 | { | |
128 | struct of_mm_gpio_chip *mm_gc; | |
129 | ||
130 | mm_gc = to_of_mm_gpio_chip(gc); | |
131 | ||
132 | return !!(readl(mm_gc->regs + ALTERA_GPIO_DATA) & BIT(offset)); | |
133 | } | |
134 | ||
135 | static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value) | |
136 | { | |
137 | struct of_mm_gpio_chip *mm_gc; | |
138 | struct altera_gpio_chip *chip; | |
139 | unsigned long flags; | |
140 | unsigned int data_reg; | |
141 | ||
142 | mm_gc = to_of_mm_gpio_chip(gc); | |
143 | chip = container_of(mm_gc, struct altera_gpio_chip, mmchip); | |
144 | ||
145 | spin_lock_irqsave(&chip->gpio_lock, flags); | |
146 | data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA); | |
147 | if (value) | |
148 | data_reg |= BIT(offset); | |
149 | else | |
150 | data_reg &= ~BIT(offset); | |
151 | writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA); | |
152 | spin_unlock_irqrestore(&chip->gpio_lock, flags); | |
153 | } | |
154 | ||
155 | static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset) | |
156 | { | |
157 | struct of_mm_gpio_chip *mm_gc; | |
158 | struct altera_gpio_chip *chip; | |
159 | unsigned long flags; | |
160 | unsigned int gpio_ddr; | |
161 | ||
162 | mm_gc = to_of_mm_gpio_chip(gc); | |
163 | chip = container_of(mm_gc, struct altera_gpio_chip, mmchip); | |
164 | ||
165 | spin_lock_irqsave(&chip->gpio_lock, flags); | |
166 | /* Set pin as input, assumes software controlled IP */ | |
167 | gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR); | |
168 | gpio_ddr &= ~BIT(offset); | |
169 | writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR); | |
170 | spin_unlock_irqrestore(&chip->gpio_lock, flags); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | static int altera_gpio_direction_output(struct gpio_chip *gc, | |
176 | unsigned offset, int value) | |
177 | { | |
178 | struct of_mm_gpio_chip *mm_gc; | |
179 | struct altera_gpio_chip *chip; | |
180 | unsigned long flags; | |
181 | unsigned int data_reg, gpio_ddr; | |
182 | ||
183 | mm_gc = to_of_mm_gpio_chip(gc); | |
184 | chip = container_of(mm_gc, struct altera_gpio_chip, mmchip); | |
185 | ||
186 | spin_lock_irqsave(&chip->gpio_lock, flags); | |
187 | /* Sets the GPIO value */ | |
188 | data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA); | |
189 | if (value) | |
190 | data_reg |= BIT(offset); | |
191 | else | |
192 | data_reg &= ~BIT(offset); | |
193 | writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA); | |
194 | ||
195 | /* Set pin as output, assumes software controlled IP */ | |
196 | gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR); | |
197 | gpio_ddr |= BIT(offset); | |
198 | writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR); | |
199 | spin_unlock_irqrestore(&chip->gpio_lock, flags); | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static void altera_gpio_irq_edge_handler(unsigned int irq, | |
205 | struct irq_desc *desc) | |
206 | { | |
207 | struct altera_gpio_chip *altera_gc; | |
208 | struct irq_chip *chip; | |
209 | struct of_mm_gpio_chip *mm_gc; | |
210 | struct irq_domain *irqdomain; | |
211 | unsigned long status; | |
212 | int i; | |
213 | ||
214 | altera_gc = irq_desc_get_handler_data(desc); | |
215 | chip = irq_desc_get_chip(desc); | |
216 | mm_gc = &altera_gc->mmchip; | |
217 | irqdomain = altera_gc->mmchip.gc.irqdomain; | |
218 | ||
219 | chained_irq_enter(chip, desc); | |
220 | ||
221 | while ((status = | |
222 | (readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP) & | |
223 | readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK)))) { | |
224 | writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP); | |
225 | for_each_set_bit(i, &status, mm_gc->gc.ngpio) { | |
226 | generic_handle_irq(irq_find_mapping(irqdomain, i)); | |
227 | } | |
228 | } | |
229 | ||
230 | chained_irq_exit(chip, desc); | |
231 | } | |
232 | ||
233 | ||
234 | static void altera_gpio_irq_leveL_high_handler(unsigned int irq, | |
235 | struct irq_desc *desc) | |
236 | { | |
237 | struct altera_gpio_chip *altera_gc; | |
238 | struct irq_chip *chip; | |
239 | struct of_mm_gpio_chip *mm_gc; | |
240 | struct irq_domain *irqdomain; | |
241 | unsigned long status; | |
242 | int i; | |
243 | ||
244 | altera_gc = irq_desc_get_handler_data(desc); | |
245 | chip = irq_desc_get_chip(desc); | |
246 | mm_gc = &altera_gc->mmchip; | |
247 | irqdomain = altera_gc->mmchip.gc.irqdomain; | |
248 | ||
249 | chained_irq_enter(chip, desc); | |
250 | ||
251 | status = readl(mm_gc->regs + ALTERA_GPIO_DATA); | |
252 | status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK); | |
253 | ||
254 | for_each_set_bit(i, &status, mm_gc->gc.ngpio) { | |
255 | generic_handle_irq(irq_find_mapping(irqdomain, i)); | |
256 | } | |
257 | chained_irq_exit(chip, desc); | |
258 | } | |
259 | ||
c4b40493 | 260 | static int altera_gpio_probe(struct platform_device *pdev) |
c5abbba9 THL |
261 | { |
262 | struct device_node *node = pdev->dev.of_node; | |
263 | int reg, ret; | |
264 | struct altera_gpio_chip *altera_gc; | |
265 | ||
266 | altera_gc = devm_kzalloc(&pdev->dev, sizeof(*altera_gc), GFP_KERNEL); | |
267 | if (!altera_gc) | |
268 | return -ENOMEM; | |
269 | ||
270 | spin_lock_init(&altera_gc->gpio_lock); | |
271 | ||
272 | if (of_property_read_u32(node, "altr,ngpio", ®)) | |
273 | /* By default assume maximum ngpio */ | |
274 | altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO; | |
275 | else | |
276 | altera_gc->mmchip.gc.ngpio = reg; | |
277 | ||
278 | if (altera_gc->mmchip.gc.ngpio > ALTERA_GPIO_MAX_NGPIO) { | |
279 | dev_warn(&pdev->dev, | |
280 | "ngpio is greater than %d, defaulting to %d\n", | |
281 | ALTERA_GPIO_MAX_NGPIO, ALTERA_GPIO_MAX_NGPIO); | |
282 | altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO; | |
283 | } | |
284 | ||
285 | altera_gc->mmchip.gc.direction_input = altera_gpio_direction_input; | |
286 | altera_gc->mmchip.gc.direction_output = altera_gpio_direction_output; | |
287 | altera_gc->mmchip.gc.get = altera_gpio_get; | |
288 | altera_gc->mmchip.gc.set = altera_gpio_set; | |
289 | altera_gc->mmchip.gc.owner = THIS_MODULE; | |
290 | altera_gc->mmchip.gc.dev = &pdev->dev; | |
291 | ||
292 | ret = of_mm_gpiochip_add(node, &altera_gc->mmchip); | |
293 | if (ret) { | |
294 | dev_err(&pdev->dev, "Failed adding memory mapped gpiochip\n"); | |
295 | return ret; | |
296 | } | |
297 | ||
298 | platform_set_drvdata(pdev, altera_gc); | |
299 | ||
300 | altera_gc->mapped_irq = platform_get_irq(pdev, 0); | |
301 | ||
302 | if (altera_gc->mapped_irq < 0) | |
303 | goto skip_irq; | |
304 | ||
305 | if (of_property_read_u32(node, "altr,interrupt-type", ®)) { | |
306 | ret = -EINVAL; | |
307 | dev_err(&pdev->dev, | |
308 | "altr,interrupt-type value not set in device tree\n"); | |
309 | goto teardown; | |
310 | } | |
311 | altera_gc->interrupt_trigger = reg; | |
312 | ||
313 | ret = gpiochip_irqchip_add(&altera_gc->mmchip.gc, &altera_irq_chip, 0, | |
314 | handle_simple_irq, IRQ_TYPE_NONE); | |
315 | ||
316 | if (ret) { | |
317 | dev_info(&pdev->dev, "could not add irqchip\n"); | |
318 | return ret; | |
319 | } | |
320 | ||
321 | gpiochip_set_chained_irqchip(&altera_gc->mmchip.gc, | |
322 | &altera_irq_chip, | |
323 | altera_gc->mapped_irq, | |
324 | altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH ? | |
325 | altera_gpio_irq_leveL_high_handler : | |
326 | altera_gpio_irq_edge_handler); | |
327 | ||
328 | skip_irq: | |
329 | return 0; | |
330 | teardown: | |
331 | pr_err("%s: registration failed with status %d\n", | |
332 | node->full_name, ret); | |
333 | ||
334 | return ret; | |
335 | } | |
336 | ||
337 | static int altera_gpio_remove(struct platform_device *pdev) | |
338 | { | |
339 | struct altera_gpio_chip *altera_gc = platform_get_drvdata(pdev); | |
340 | ||
341 | gpiochip_remove(&altera_gc->mmchip.gc); | |
342 | ||
343 | return -EIO; | |
344 | } | |
345 | ||
346 | static const struct of_device_id altera_gpio_of_match[] = { | |
347 | { .compatible = "altr,pio-1.0", }, | |
348 | {}, | |
349 | }; | |
350 | MODULE_DEVICE_TABLE(of, altera_gpio_of_match); | |
351 | ||
352 | static struct platform_driver altera_gpio_driver = { | |
353 | .driver = { | |
354 | .name = "altera_gpio", | |
355 | .of_match_table = of_match_ptr(altera_gpio_of_match), | |
356 | }, | |
357 | .probe = altera_gpio_probe, | |
358 | .remove = altera_gpio_remove, | |
359 | }; | |
360 | ||
361 | static int __init altera_gpio_init(void) | |
362 | { | |
363 | return platform_driver_register(&altera_gpio_driver); | |
364 | } | |
365 | subsys_initcall(altera_gpio_init); | |
366 | ||
367 | static void __exit altera_gpio_exit(void) | |
368 | { | |
369 | platform_driver_unregister(&altera_gpio_driver); | |
370 | } | |
371 | module_exit(altera_gpio_exit); | |
372 | ||
373 | MODULE_AUTHOR("Tien Hock Loh <thloh@altera.com>"); | |
374 | MODULE_DESCRIPTION("Altera GPIO driver"); | |
375 | MODULE_LICENSE("GPL"); |