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1 | /* | |
2 | * Generic EP93xx GPIO handling | |
3 | * | |
4 | * Copyright (c) 2008 Ryan Mallon | |
5 | * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com> | |
6 | * | |
7 | * Based on code originally from: | |
8 | * linux/arch/arm/mach-ep93xx/core.c | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/init.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/gpio.h> | |
20 | #include <linux/irq.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/basic_mmio_gpio.h> | |
23 | ||
24 | #include <mach/hardware.h> | |
25 | #include <mach/gpio-ep93xx.h> | |
26 | ||
27 | #define irq_to_gpio(irq) ((irq) - gpio_to_irq(0)) | |
28 | ||
29 | struct ep93xx_gpio { | |
30 | void __iomem *mmio_base; | |
31 | struct bgpio_chip bgc[8]; | |
32 | }; | |
33 | ||
34 | /************************************************************************* | |
35 | * Interrupt handling for EP93xx on-chip GPIOs | |
36 | *************************************************************************/ | |
37 | static unsigned char gpio_int_unmasked[3]; | |
38 | static unsigned char gpio_int_enabled[3]; | |
39 | static unsigned char gpio_int_type1[3]; | |
40 | static unsigned char gpio_int_type2[3]; | |
41 | static unsigned char gpio_int_debounce[3]; | |
42 | ||
43 | /* Port ordering is: A B F */ | |
44 | static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c }; | |
45 | static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 }; | |
46 | static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 }; | |
47 | static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 }; | |
48 | static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 }; | |
49 | ||
50 | static void ep93xx_gpio_update_int_params(unsigned port) | |
51 | { | |
52 | BUG_ON(port > 2); | |
53 | ||
54 | __raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port])); | |
55 | ||
56 | __raw_writeb(gpio_int_type2[port], | |
57 | EP93XX_GPIO_REG(int_type2_register_offset[port])); | |
58 | ||
59 | __raw_writeb(gpio_int_type1[port], | |
60 | EP93XX_GPIO_REG(int_type1_register_offset[port])); | |
61 | ||
62 | __raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port], | |
63 | EP93XX_GPIO_REG(int_en_register_offset[port])); | |
64 | } | |
65 | ||
66 | static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable) | |
67 | { | |
68 | int line = irq_to_gpio(irq); | |
69 | int port = line >> 3; | |
70 | int port_mask = 1 << (line & 7); | |
71 | ||
72 | if (enable) | |
73 | gpio_int_debounce[port] |= port_mask; | |
74 | else | |
75 | gpio_int_debounce[port] &= ~port_mask; | |
76 | ||
77 | __raw_writeb(gpio_int_debounce[port], | |
78 | EP93XX_GPIO_REG(int_debounce_register_offset[port])); | |
79 | } | |
80 | ||
81 | static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc) | |
82 | { | |
83 | unsigned char status; | |
84 | int i; | |
85 | ||
86 | status = __raw_readb(EP93XX_GPIO_A_INT_STATUS); | |
87 | for (i = 0; i < 8; i++) { | |
88 | if (status & (1 << i)) { | |
89 | int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i; | |
90 | generic_handle_irq(gpio_irq); | |
91 | } | |
92 | } | |
93 | ||
94 | status = __raw_readb(EP93XX_GPIO_B_INT_STATUS); | |
95 | for (i = 0; i < 8; i++) { | |
96 | if (status & (1 << i)) { | |
97 | int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i; | |
98 | generic_handle_irq(gpio_irq); | |
99 | } | |
100 | } | |
101 | } | |
102 | ||
103 | static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc) | |
104 | { | |
105 | /* | |
106 | * map discontiguous hw irq range to continuous sw irq range: | |
107 | * | |
108 | * IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7}) | |
109 | */ | |
110 | int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */ | |
111 | int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx; | |
112 | ||
113 | generic_handle_irq(gpio_irq); | |
114 | } | |
115 | ||
116 | static void ep93xx_gpio_irq_ack(struct irq_data *d) | |
117 | { | |
118 | int line = irq_to_gpio(d->irq); | |
119 | int port = line >> 3; | |
120 | int port_mask = 1 << (line & 7); | |
121 | ||
122 | if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) { | |
123 | gpio_int_type2[port] ^= port_mask; /* switch edge direction */ | |
124 | ep93xx_gpio_update_int_params(port); | |
125 | } | |
126 | ||
127 | __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port])); | |
128 | } | |
129 | ||
130 | static void ep93xx_gpio_irq_mask_ack(struct irq_data *d) | |
131 | { | |
132 | int line = irq_to_gpio(d->irq); | |
133 | int port = line >> 3; | |
134 | int port_mask = 1 << (line & 7); | |
135 | ||
136 | if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) | |
137 | gpio_int_type2[port] ^= port_mask; /* switch edge direction */ | |
138 | ||
139 | gpio_int_unmasked[port] &= ~port_mask; | |
140 | ep93xx_gpio_update_int_params(port); | |
141 | ||
142 | __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port])); | |
143 | } | |
144 | ||
145 | static void ep93xx_gpio_irq_mask(struct irq_data *d) | |
146 | { | |
147 | int line = irq_to_gpio(d->irq); | |
148 | int port = line >> 3; | |
149 | ||
150 | gpio_int_unmasked[port] &= ~(1 << (line & 7)); | |
151 | ep93xx_gpio_update_int_params(port); | |
152 | } | |
153 | ||
154 | static void ep93xx_gpio_irq_unmask(struct irq_data *d) | |
155 | { | |
156 | int line = irq_to_gpio(d->irq); | |
157 | int port = line >> 3; | |
158 | ||
159 | gpio_int_unmasked[port] |= 1 << (line & 7); | |
160 | ep93xx_gpio_update_int_params(port); | |
161 | } | |
162 | ||
163 | /* | |
164 | * gpio_int_type1 controls whether the interrupt is level (0) or | |
165 | * edge (1) triggered, while gpio_int_type2 controls whether it | |
166 | * triggers on low/falling (0) or high/rising (1). | |
167 | */ | |
168 | static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type) | |
169 | { | |
170 | const int gpio = irq_to_gpio(d->irq); | |
171 | const int port = gpio >> 3; | |
172 | const int port_mask = 1 << (gpio & 7); | |
173 | irq_flow_handler_t handler; | |
174 | ||
175 | gpio_direction_input(gpio); | |
176 | ||
177 | switch (type) { | |
178 | case IRQ_TYPE_EDGE_RISING: | |
179 | gpio_int_type1[port] |= port_mask; | |
180 | gpio_int_type2[port] |= port_mask; | |
181 | handler = handle_edge_irq; | |
182 | break; | |
183 | case IRQ_TYPE_EDGE_FALLING: | |
184 | gpio_int_type1[port] |= port_mask; | |
185 | gpio_int_type2[port] &= ~port_mask; | |
186 | handler = handle_edge_irq; | |
187 | break; | |
188 | case IRQ_TYPE_LEVEL_HIGH: | |
189 | gpio_int_type1[port] &= ~port_mask; | |
190 | gpio_int_type2[port] |= port_mask; | |
191 | handler = handle_level_irq; | |
192 | break; | |
193 | case IRQ_TYPE_LEVEL_LOW: | |
194 | gpio_int_type1[port] &= ~port_mask; | |
195 | gpio_int_type2[port] &= ~port_mask; | |
196 | handler = handle_level_irq; | |
197 | break; | |
198 | case IRQ_TYPE_EDGE_BOTH: | |
199 | gpio_int_type1[port] |= port_mask; | |
200 | /* set initial polarity based on current input level */ | |
201 | if (gpio_get_value(gpio)) | |
202 | gpio_int_type2[port] &= ~port_mask; /* falling */ | |
203 | else | |
204 | gpio_int_type2[port] |= port_mask; /* rising */ | |
205 | handler = handle_edge_irq; | |
206 | break; | |
207 | default: | |
208 | return -EINVAL; | |
209 | } | |
210 | ||
211 | __irq_set_handler_locked(d->irq, handler); | |
212 | ||
213 | gpio_int_enabled[port] |= port_mask; | |
214 | ||
215 | ep93xx_gpio_update_int_params(port); | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | static struct irq_chip ep93xx_gpio_irq_chip = { | |
221 | .name = "GPIO", | |
222 | .irq_ack = ep93xx_gpio_irq_ack, | |
223 | .irq_mask_ack = ep93xx_gpio_irq_mask_ack, | |
224 | .irq_mask = ep93xx_gpio_irq_mask, | |
225 | .irq_unmask = ep93xx_gpio_irq_unmask, | |
226 | .irq_set_type = ep93xx_gpio_irq_type, | |
227 | }; | |
228 | ||
229 | static void ep93xx_gpio_init_irq(void) | |
230 | { | |
231 | int gpio_irq; | |
232 | ||
233 | for (gpio_irq = gpio_to_irq(0); | |
234 | gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) { | |
235 | irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip, | |
236 | handle_level_irq); | |
237 | set_irq_flags(gpio_irq, IRQF_VALID); | |
238 | } | |
239 | ||
240 | irq_set_chained_handler(IRQ_EP93XX_GPIO_AB, | |
241 | ep93xx_gpio_ab_irq_handler); | |
242 | irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX, | |
243 | ep93xx_gpio_f_irq_handler); | |
244 | irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX, | |
245 | ep93xx_gpio_f_irq_handler); | |
246 | irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX, | |
247 | ep93xx_gpio_f_irq_handler); | |
248 | irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX, | |
249 | ep93xx_gpio_f_irq_handler); | |
250 | irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX, | |
251 | ep93xx_gpio_f_irq_handler); | |
252 | irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX, | |
253 | ep93xx_gpio_f_irq_handler); | |
254 | irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX, | |
255 | ep93xx_gpio_f_irq_handler); | |
256 | irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX, | |
257 | ep93xx_gpio_f_irq_handler); | |
258 | } | |
259 | ||
260 | ||
261 | /************************************************************************* | |
262 | * gpiolib interface for EP93xx on-chip GPIOs | |
263 | *************************************************************************/ | |
264 | struct ep93xx_gpio_bank { | |
265 | const char *label; | |
266 | int data; | |
267 | int dir; | |
268 | int base; | |
269 | bool has_debounce; | |
270 | }; | |
271 | ||
272 | #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \ | |
273 | { \ | |
274 | .label = _label, \ | |
275 | .data = _data, \ | |
276 | .dir = _dir, \ | |
277 | .base = _base, \ | |
278 | .has_debounce = _debounce, \ | |
279 | } | |
280 | ||
281 | static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = { | |
282 | EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true), | |
283 | EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true), | |
284 | EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false), | |
285 | EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false), | |
286 | EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false), | |
287 | EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true), | |
288 | EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false), | |
289 | EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false), | |
290 | }; | |
291 | ||
292 | static int ep93xx_gpio_set_debounce(struct gpio_chip *chip, | |
293 | unsigned offset, unsigned debounce) | |
294 | { | |
295 | int gpio = chip->base + offset; | |
296 | int irq = gpio_to_irq(gpio); | |
297 | ||
298 | if (irq < 0) | |
299 | return -EINVAL; | |
300 | ||
301 | ep93xx_gpio_int_debounce(irq, debounce ? true : false); | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | /* | |
307 | * Map GPIO A0..A7 (0..7) to irq 64..71, | |
308 | * B0..B7 (7..15) to irq 72..79, and | |
309 | * F0..F7 (16..24) to irq 80..87. | |
310 | */ | |
311 | static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset) | |
312 | { | |
313 | int gpio = chip->base + offset; | |
314 | ||
315 | if (gpio > EP93XX_GPIO_LINE_MAX_IRQ) | |
316 | return -EINVAL; | |
317 | ||
318 | return 64 + gpio; | |
319 | } | |
320 | ||
321 | static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev, | |
322 | void __iomem *mmio_base, struct ep93xx_gpio_bank *bank) | |
323 | { | |
324 | void __iomem *data = mmio_base + bank->data; | |
325 | void __iomem *dir = mmio_base + bank->dir; | |
326 | int err; | |
327 | ||
328 | err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, false); | |
329 | if (err) | |
330 | return err; | |
331 | ||
332 | bgc->gc.label = bank->label; | |
333 | bgc->gc.base = bank->base; | |
334 | ||
335 | if (bank->has_debounce) { | |
336 | bgc->gc.set_debounce = ep93xx_gpio_set_debounce; | |
337 | bgc->gc.to_irq = ep93xx_gpio_to_irq; | |
338 | } | |
339 | ||
340 | return gpiochip_add(&bgc->gc); | |
341 | } | |
342 | ||
343 | static int __devinit ep93xx_gpio_probe(struct platform_device *pdev) | |
344 | { | |
345 | struct ep93xx_gpio *ep93xx_gpio; | |
346 | struct resource *res; | |
347 | void __iomem *mmio; | |
348 | int i; | |
349 | int ret; | |
350 | ||
351 | ep93xx_gpio = kzalloc(sizeof(*ep93xx_gpio), GFP_KERNEL); | |
352 | if (!ep93xx_gpio) | |
353 | return -ENOMEM; | |
354 | ||
355 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
356 | if (!res) { | |
357 | ret = -ENXIO; | |
358 | goto exit_free; | |
359 | } | |
360 | ||
361 | if (!request_mem_region(res->start, resource_size(res), pdev->name)) { | |
362 | ret = -EBUSY; | |
363 | goto exit_free; | |
364 | } | |
365 | ||
366 | mmio = ioremap(res->start, resource_size(res)); | |
367 | if (!mmio) { | |
368 | ret = -ENXIO; | |
369 | goto exit_release; | |
370 | } | |
371 | ep93xx_gpio->mmio_base = mmio; | |
372 | ||
373 | for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) { | |
374 | struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i]; | |
375 | struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i]; | |
376 | ||
377 | if (ep93xx_gpio_add_bank(bgc, &pdev->dev, mmio, bank)) | |
378 | dev_warn(&pdev->dev, "Unable to add gpio bank %s\n", | |
379 | bank->label); | |
380 | } | |
381 | ||
382 | ep93xx_gpio_init_irq(); | |
383 | ||
384 | return 0; | |
385 | ||
386 | exit_release: | |
387 | release_mem_region(res->start, resource_size(res)); | |
388 | exit_free: | |
389 | kfree(ep93xx_gpio); | |
390 | dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, ret); | |
391 | return ret; | |
392 | } | |
393 | ||
394 | static struct platform_driver ep93xx_gpio_driver = { | |
395 | .driver = { | |
396 | .name = "gpio-ep93xx", | |
397 | .owner = THIS_MODULE, | |
398 | }, | |
399 | .probe = ep93xx_gpio_probe, | |
400 | }; | |
401 | ||
402 | static int __init ep93xx_gpio_init(void) | |
403 | { | |
404 | return platform_driver_register(&ep93xx_gpio_driver); | |
405 | } | |
406 | postcore_initcall(ep93xx_gpio_init); | |
407 | ||
408 | MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> " | |
409 | "H Hartley Sweeten <hsweeten@visionengravers.com>"); | |
410 | MODULE_DESCRIPTION("EP93XX GPIO driver"); | |
411 | MODULE_LICENSE("GPL"); |