1 /*
2 * linux/arch/arm/mach-ep93xx/gpio.c
3 *
4 * Generic EP93xx GPIO handling
5 *
6 * Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com>
7 *
8 * Based on code originally from:
9 * linux/arch/arm/mach-ep93xx/core.c
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 #define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
17
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/seq_file.h>
21 #include <linux/io.h>
22 #include <linux/gpio.h>
23 #include <linux/irq.h>
24
25 #include <mach/hardware.h>
26
27 /*************************************************************************
28 * Interrupt handling for EP93xx on-chip GPIOs
29 *************************************************************************/
30 static unsigned char gpio_int_unmasked[3];
31 static unsigned char gpio_int_enabled[3];
32 static unsigned char gpio_int_type1[3];
33 static unsigned char gpio_int_type2[3];
34 static unsigned char gpio_int_debounce[3];
35
36 /* Port ordering is: A B F */
37 static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
38 static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
39 static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
40 static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
41 static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
42
ep93xx_gpio_update_int_params(unsigned port)43 static void ep93xx_gpio_update_int_params(unsigned port)
44 {
45 BUG_ON(port > 2);
46
47 __raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
48
49 __raw_writeb(gpio_int_type2[port],
50 EP93XX_GPIO_REG(int_type2_register_offset[port]));
51
52 __raw_writeb(gpio_int_type1[port],
53 EP93XX_GPIO_REG(int_type1_register_offset[port]));
54
55 __raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
56 EP93XX_GPIO_REG(int_en_register_offset[port]));
57 }
58
ep93xx_gpio_int_mask(unsigned line)59 static inline void ep93xx_gpio_int_mask(unsigned line)
60 {
61 gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
62 }
63
ep93xx_gpio_int_debounce(unsigned int irq,bool enable)64 static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
65 {
66 int line = irq_to_gpio(irq);
67 int port = line >> 3;
68 int port_mask = 1 << (line & 7);
69
70 if (enable)
71 gpio_int_debounce[port] |= port_mask;
72 else
73 gpio_int_debounce[port] &= ~port_mask;
74
75 __raw_writeb(gpio_int_debounce[port],
76 EP93XX_GPIO_REG(int_debounce_register_offset[port]));
77 }
78
ep93xx_gpio_ab_irq_handler(unsigned int irq,struct irq_desc * desc)79 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
80 {
81 unsigned char status;
82 int i;
83
84 status = __raw_readb(EP93XX_GPIO_A_INT_STATUS);
85 for (i = 0; i < 8; i++) {
86 if (status & (1 << i)) {
87 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
88 generic_handle_irq(gpio_irq);
89 }
90 }
91
92 status = __raw_readb(EP93XX_GPIO_B_INT_STATUS);
93 for (i = 0; i < 8; i++) {
94 if (status & (1 << i)) {
95 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
96 generic_handle_irq(gpio_irq);
97 }
98 }
99 }
100
ep93xx_gpio_f_irq_handler(unsigned int irq,struct irq_desc * desc)101 static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
102 {
103 /*
104 * map discontiguous hw irq range to continuous sw irq range:
105 *
106 * IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
107 */
108 int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
109 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
110
111 generic_handle_irq(gpio_irq);
112 }
113
ep93xx_gpio_irq_ack(struct irq_data * d)114 static void ep93xx_gpio_irq_ack(struct irq_data *d)
115 {
116 int line = irq_to_gpio(d->irq);
117 int port = line >> 3;
118 int port_mask = 1 << (line & 7);
119
120 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
121 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
122 ep93xx_gpio_update_int_params(port);
123 }
124
125 __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
126 }
127
ep93xx_gpio_irq_mask_ack(struct irq_data * d)128 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
129 {
130 int line = irq_to_gpio(d->irq);
131 int port = line >> 3;
132 int port_mask = 1 << (line & 7);
133
134 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
135 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
136
137 gpio_int_unmasked[port] &= ~port_mask;
138 ep93xx_gpio_update_int_params(port);
139
140 __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
141 }
142
ep93xx_gpio_irq_mask(struct irq_data * d)143 static void ep93xx_gpio_irq_mask(struct irq_data *d)
144 {
145 int line = irq_to_gpio(d->irq);
146 int port = line >> 3;
147
148 gpio_int_unmasked[port] &= ~(1 << (line & 7));
149 ep93xx_gpio_update_int_params(port);
150 }
151
ep93xx_gpio_irq_unmask(struct irq_data * d)152 static void ep93xx_gpio_irq_unmask(struct irq_data *d)
153 {
154 int line = irq_to_gpio(d->irq);
155 int port = line >> 3;
156
157 gpio_int_unmasked[port] |= 1 << (line & 7);
158 ep93xx_gpio_update_int_params(port);
159 }
160
161 /*
162 * gpio_int_type1 controls whether the interrupt is level (0) or
163 * edge (1) triggered, while gpio_int_type2 controls whether it
164 * triggers on low/falling (0) or high/rising (1).
165 */
ep93xx_gpio_irq_type(struct irq_data * d,unsigned int type)166 static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
167 {
168 const int gpio = irq_to_gpio(d->irq);
169 const int port = gpio >> 3;
170 const int port_mask = 1 << (gpio & 7);
171 irq_flow_handler_t handler;
172
173 gpio_direction_input(gpio);
174
175 switch (type) {
176 case IRQ_TYPE_EDGE_RISING:
177 gpio_int_type1[port] |= port_mask;
178 gpio_int_type2[port] |= port_mask;
179 handler = handle_edge_irq;
180 break;
181 case IRQ_TYPE_EDGE_FALLING:
182 gpio_int_type1[port] |= port_mask;
183 gpio_int_type2[port] &= ~port_mask;
184 handler = handle_edge_irq;
185 break;
186 case IRQ_TYPE_LEVEL_HIGH:
187 gpio_int_type1[port] &= ~port_mask;
188 gpio_int_type2[port] |= port_mask;
189 handler = handle_level_irq;
190 break;
191 case IRQ_TYPE_LEVEL_LOW:
192 gpio_int_type1[port] &= ~port_mask;
193 gpio_int_type2[port] &= ~port_mask;
194 handler = handle_level_irq;
195 break;
196 case IRQ_TYPE_EDGE_BOTH:
197 gpio_int_type1[port] |= port_mask;
198 /* set initial polarity based on current input level */
199 if (gpio_get_value(gpio))
200 gpio_int_type2[port] &= ~port_mask; /* falling */
201 else
202 gpio_int_type2[port] |= port_mask; /* rising */
203 handler = handle_edge_irq;
204 break;
205 default:
206 pr_err("failed to set irq type %d for gpio %d\n", type, gpio);
207 return -EINVAL;
208 }
209
210 __irq_set_handler_locked(d->irq, handler);
211
212 gpio_int_enabled[port] |= port_mask;
213
214 ep93xx_gpio_update_int_params(port);
215
216 return 0;
217 }
218
219 static struct irq_chip ep93xx_gpio_irq_chip = {
220 .name = "GPIO",
221 .irq_ack = ep93xx_gpio_irq_ack,
222 .irq_mask_ack = ep93xx_gpio_irq_mask_ack,
223 .irq_mask = ep93xx_gpio_irq_mask,
224 .irq_unmask = ep93xx_gpio_irq_unmask,
225 .irq_set_type = ep93xx_gpio_irq_type,
226 };
227
ep93xx_gpio_init_irq(void)228 void __init ep93xx_gpio_init_irq(void)
229 {
230 int gpio_irq;
231
232 for (gpio_irq = gpio_to_irq(0);
233 gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
234 irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
235 handle_level_irq);
236 set_irq_flags(gpio_irq, IRQF_VALID);
237 }
238
239 irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
240 ep93xx_gpio_ab_irq_handler);
241 irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
242 ep93xx_gpio_f_irq_handler);
243 irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
244 ep93xx_gpio_f_irq_handler);
245 irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
246 ep93xx_gpio_f_irq_handler);
247 irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
248 ep93xx_gpio_f_irq_handler);
249 irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
250 ep93xx_gpio_f_irq_handler);
251 irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
252 ep93xx_gpio_f_irq_handler);
253 irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
254 ep93xx_gpio_f_irq_handler);
255 irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
256 ep93xx_gpio_f_irq_handler);
257 }
258
259
260 /*************************************************************************
261 * gpiolib interface for EP93xx on-chip GPIOs
262 *************************************************************************/
263 struct ep93xx_gpio_chip {
264 struct gpio_chip chip;
265
266 void __iomem *data_reg;
267 void __iomem *data_dir_reg;
268 };
269
270 #define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip)
271
ep93xx_gpio_direction_input(struct gpio_chip * chip,unsigned offset)272 static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
273 {
274 struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
275 unsigned long flags;
276 u8 v;
277
278 local_irq_save(flags);
279 v = __raw_readb(ep93xx_chip->data_dir_reg);
280 v &= ~(1 << offset);
281 __raw_writeb(v, ep93xx_chip->data_dir_reg);
282 local_irq_restore(flags);
283
284 return 0;
285 }
286
ep93xx_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int val)287 static int ep93xx_gpio_direction_output(struct gpio_chip *chip,
288 unsigned offset, int val)
289 {
290 struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
291 unsigned long flags;
292 int line;
293 u8 v;
294
295 local_irq_save(flags);
296
297 /* Set the value */
298 v = __raw_readb(ep93xx_chip->data_reg);
299 if (val)
300 v |= (1 << offset);
301 else
302 v &= ~(1 << offset);
303 __raw_writeb(v, ep93xx_chip->data_reg);
304
305 /* Drive as an output */
306 line = chip->base + offset;
307 if (line <= EP93XX_GPIO_LINE_MAX_IRQ) {
308 /* Ports A/B/F */
309 ep93xx_gpio_int_mask(line);
310 ep93xx_gpio_update_int_params(line >> 3);
311 }
312
313 v = __raw_readb(ep93xx_chip->data_dir_reg);
314 v |= (1 << offset);
315 __raw_writeb(v, ep93xx_chip->data_dir_reg);
316
317 local_irq_restore(flags);
318
319 return 0;
320 }
321
ep93xx_gpio_get(struct gpio_chip * chip,unsigned offset)322 static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset)
323 {
324 struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
325
326 return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset));
327 }
328
ep93xx_gpio_set(struct gpio_chip * chip,unsigned offset,int val)329 static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
330 {
331 struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
332 unsigned long flags;
333 u8 v;
334
335 local_irq_save(flags);
336 v = __raw_readb(ep93xx_chip->data_reg);
337 if (val)
338 v |= (1 << offset);
339 else
340 v &= ~(1 << offset);
341 __raw_writeb(v, ep93xx_chip->data_reg);
342 local_irq_restore(flags);
343 }
344
ep93xx_gpio_set_debounce(struct gpio_chip * chip,unsigned offset,unsigned debounce)345 static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
346 unsigned offset, unsigned debounce)
347 {
348 int gpio = chip->base + offset;
349 int irq = gpio_to_irq(gpio);
350
351 if (irq < 0)
352 return -EINVAL;
353
354 ep93xx_gpio_int_debounce(irq, debounce ? true : false);
355
356 return 0;
357 }
358
ep93xx_gpio_dbg_show(struct seq_file * s,struct gpio_chip * chip)359 static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
360 {
361 struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
362 u8 data_reg, data_dir_reg;
363 int gpio, i;
364
365 data_reg = __raw_readb(ep93xx_chip->data_reg);
366 data_dir_reg = __raw_readb(ep93xx_chip->data_dir_reg);
367
368 gpio = ep93xx_chip->chip.base;
369 for (i = 0; i < chip->ngpio; i++, gpio++) {
370 int is_out = data_dir_reg & (1 << i);
371 int irq = gpio_to_irq(gpio);
372
373 seq_printf(s, " %s%d gpio-%-3d (%-12s) %s %s %s\n",
374 chip->label, i, gpio,
375 gpiochip_is_requested(chip, i) ? : "",
376 is_out ? "out" : "in ",
377 (data_reg & (1<< i)) ? "hi" : "lo",
378 (!is_out && irq>= 0) ? "(interrupt)" : "");
379 }
380 }
381
382 #define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio) \
383 { \
384 .chip = { \
385 .label = name, \
386 .direction_input = ep93xx_gpio_direction_input, \
387 .direction_output = ep93xx_gpio_direction_output, \
388 .get = ep93xx_gpio_get, \
389 .set = ep93xx_gpio_set, \
390 .dbg_show = ep93xx_gpio_dbg_show, \
391 .base = base_gpio, \
392 .ngpio = 8, \
393 }, \
394 .data_reg = EP93XX_GPIO_REG(dr), \
395 .data_dir_reg = EP93XX_GPIO_REG(ddr), \
396 }
397
398 static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = {
399 EP93XX_GPIO_BANK("A", 0x00, 0x10, 0),
400 EP93XX_GPIO_BANK("B", 0x04, 0x14, 8),
401 EP93XX_GPIO_BANK("C", 0x08, 0x18, 40),
402 EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24),
403 EP93XX_GPIO_BANK("E", 0x20, 0x24, 32),
404 EP93XX_GPIO_BANK("F", 0x30, 0x34, 16),
405 EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48),
406 EP93XX_GPIO_BANK("H", 0x40, 0x44, 56),
407 };
408
ep93xx_gpio_init(void)409 void __init ep93xx_gpio_init(void)
410 {
411 int i;
412
413 /* Set Ports C, D, E, G, and H for GPIO use */
414 ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_KEYS |
415 EP93XX_SYSCON_DEVCFG_GONK |
416 EP93XX_SYSCON_DEVCFG_EONIDE |
417 EP93XX_SYSCON_DEVCFG_GONIDE |
418 EP93XX_SYSCON_DEVCFG_HONIDE);
419
420 for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
421 struct gpio_chip *chip = &ep93xx_gpio_banks[i].chip;
422
423 /*
424 * Ports A, B, and F support input debouncing when
425 * used as interrupts.
426 */
427 if (!strcmp(chip->label, "A") ||
428 !strcmp(chip->label, "B") ||
429 !strcmp(chip->label, "F"))
430 chip->set_debounce = ep93xx_gpio_set_debounce;
431
432 gpiochip_add(chip);
433 }
434 }
435