tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17#include <linux/init.h>
18#include <linux/platform_device.h>
19#include <linux/io.h>
20#include <linux/gpio.h>
21#include <linux/irq.h>
22#include <linux/slab.h>
23#include <linux/basic_mmio_gpio.h>
24
25#include <mach/hardware.h>
26
27struct ep93xx_gpio {
28 void __iomem *mmio_base;
29 struct bgpio_chip bgc[8];
30};
31
32/*************************************************************************
33 * Interrupt handling for EP93xx on-chip GPIOs
34 *************************************************************************/
35static unsigned char gpio_int_unmasked[3];
36static unsigned char gpio_int_enabled[3];
37static unsigned char gpio_int_type1[3];
38static unsigned char gpio_int_type2[3];
39static unsigned char gpio_int_debounce[3];
40
41/* Port ordering is: A B F */
42static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
43static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
44static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
45static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
46static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
47
48static void ep93xx_gpio_update_int_params(unsigned port)
49{
50 BUG_ON(port > 2);
51
52 __raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
53
54 __raw_writeb(gpio_int_type2[port],
55 EP93XX_GPIO_REG(int_type2_register_offset[port]));
56
57 __raw_writeb(gpio_int_type1[port],
58 EP93XX_GPIO_REG(int_type1_register_offset[port]));
59
60 __raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
61 EP93XX_GPIO_REG(int_en_register_offset[port]));
62}
63
64static inline void ep93xx_gpio_int_mask(unsigned line)
65{
66 gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
67}
68
69static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
70{
71 int line = irq_to_gpio(irq);
72 int port = line >> 3;
73 int port_mask = 1 << (line & 7);
74
75 if (enable)
76 gpio_int_debounce[port] |= port_mask;
77 else
78 gpio_int_debounce[port] &= ~port_mask;
79
80 __raw_writeb(gpio_int_debounce[port],
81 EP93XX_GPIO_REG(int_debounce_register_offset[port]));
82}
83
84static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
85{
86 unsigned char status;
87 int i;
88
89 status = __raw_readb(EP93XX_GPIO_A_INT_STATUS);
90 for (i = 0; i < 8; i++) {
91 if (status & (1 << i)) {
92 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
93 generic_handle_irq(gpio_irq);
94 }
95 }
96
97 status = __raw_readb(EP93XX_GPIO_B_INT_STATUS);
98 for (i = 0; i < 8; i++) {
99 if (status & (1 << i)) {
100 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
101 generic_handle_irq(gpio_irq);
102 }
103 }
104}
105
106static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
107{
108 /*
109 * map discontiguous hw irq range to continuous sw irq range:
110 *
111 * IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
112 */
113 int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
114 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
115
116 generic_handle_irq(gpio_irq);
117}
118
119static void ep93xx_gpio_irq_ack(struct irq_data *d)
120{
121 int line = irq_to_gpio(d->irq);
122 int port = line >> 3;
123 int port_mask = 1 << (line & 7);
124
125 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
126 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
127 ep93xx_gpio_update_int_params(port);
128 }
129
130 __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
131}
132
133static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
134{
135 int line = irq_to_gpio(d->irq);
136 int port = line >> 3;
137 int port_mask = 1 << (line & 7);
138
139 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
140 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
141
142 gpio_int_unmasked[port] &= ~port_mask;
143 ep93xx_gpio_update_int_params(port);
144
145 __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
146}
147
148static void ep93xx_gpio_irq_mask(struct irq_data *d)
149{
150 int line = irq_to_gpio(d->irq);
151 int port = line >> 3;
152
153 gpio_int_unmasked[port] &= ~(1 << (line & 7));
154 ep93xx_gpio_update_int_params(port);
155}
156
157static void ep93xx_gpio_irq_unmask(struct irq_data *d)
158{
159 int line = irq_to_gpio(d->irq);
160 int port = line >> 3;
161
162 gpio_int_unmasked[port] |= 1 << (line & 7);
163 ep93xx_gpio_update_int_params(port);
164}
165
166/*
167 * gpio_int_type1 controls whether the interrupt is level (0) or
168 * edge (1) triggered, while gpio_int_type2 controls whether it
169 * triggers on low/falling (0) or high/rising (1).
170 */
171static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
172{
173 const int gpio = irq_to_gpio(d->irq);
174 const int port = gpio >> 3;
175 const int port_mask = 1 << (gpio & 7);
176 irq_flow_handler_t handler;
177
178 gpio_direction_input(gpio);
179
180 switch (type) {
181 case IRQ_TYPE_EDGE_RISING:
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_EDGE_FALLING:
187 gpio_int_type1[port] |= port_mask;
188 gpio_int_type2[port] &= ~port_mask;
189 handler = handle_edge_irq;
190 break;
191 case IRQ_TYPE_LEVEL_HIGH:
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_LEVEL_LOW:
197 gpio_int_type1[port] &= ~port_mask;
198 gpio_int_type2[port] &= ~port_mask;
199 handler = handle_level_irq;
200 break;
201 case IRQ_TYPE_EDGE_BOTH:
202 gpio_int_type1[port] |= port_mask;
203 /* set initial polarity based on current input level */
204 if (gpio_get_value(gpio))
205 gpio_int_type2[port] &= ~port_mask; /* falling */
206 else
207 gpio_int_type2[port] |= port_mask; /* rising */
208 handler = handle_edge_irq;
209 break;
210 default:
211 pr_err("failed to set irq type %d for gpio %d\n", type, gpio);
212 return -EINVAL;
213 }
214
215 __irq_set_handler_locked(d->irq, handler);
216
217 gpio_int_enabled[port] |= port_mask;
218
219 ep93xx_gpio_update_int_params(port);
220
221 return 0;
222}
223
224static struct irq_chip ep93xx_gpio_irq_chip = {
225 .name = "GPIO",
226 .irq_ack = ep93xx_gpio_irq_ack,
227 .irq_mask_ack = ep93xx_gpio_irq_mask_ack,
228 .irq_mask = ep93xx_gpio_irq_mask,
229 .irq_unmask = ep93xx_gpio_irq_unmask,
230 .irq_set_type = ep93xx_gpio_irq_type,
231};
232
233static void ep93xx_gpio_init_irq(void)
234{
235 int gpio_irq;
236
237 for (gpio_irq = gpio_to_irq(0);
238 gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
239 irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
240 handle_level_irq);
241 set_irq_flags(gpio_irq, IRQF_VALID);
242 }
243
244 irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
245 ep93xx_gpio_ab_irq_handler);
246 irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
247 ep93xx_gpio_f_irq_handler);
248 irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
249 ep93xx_gpio_f_irq_handler);
250 irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
251 ep93xx_gpio_f_irq_handler);
252 irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
253 ep93xx_gpio_f_irq_handler);
254 irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
255 ep93xx_gpio_f_irq_handler);
256 irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
257 ep93xx_gpio_f_irq_handler);
258 irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
259 ep93xx_gpio_f_irq_handler);
260 irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
261 ep93xx_gpio_f_irq_handler);
262}
263
264
265/*************************************************************************
266 * gpiolib interface for EP93xx on-chip GPIOs
267 *************************************************************************/
268struct ep93xx_gpio_bank {
269 const char *label;
270 int data;
271 int dir;
272 int base;
273 bool has_debounce;
274};
275
276#define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \
277 { \
278 .label = _label, \
279 .data = _data, \
280 .dir = _dir, \
281 .base = _base, \
282 .has_debounce = _debounce, \
283 }
284
285static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
286 EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true),
287 EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true),
288 EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false),
289 EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false),
290 EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false),
291 EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true),
292 EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false),
293 EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false),
294};
295
296static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
297 unsigned offset, unsigned debounce)
298{
299 int gpio = chip->base + offset;
300 int irq = gpio_to_irq(gpio);
301
302 if (irq < 0)
303 return -EINVAL;
304
305 ep93xx_gpio_int_debounce(irq, debounce ? true : false);
306
307 return 0;
308}
309
310static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev,
311 void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
312{
313 void __iomem *data = mmio_base + bank->data;
314 void __iomem *dir = mmio_base + bank->dir;
315 int err;
316
317 err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, false);
318 if (err)
319 return err;
320
321 bgc->gc.label = bank->label;
322 bgc->gc.base = bank->base;
323
324 if (bank->has_debounce)
325 bgc->gc.set_debounce = ep93xx_gpio_set_debounce;
326
327 return gpiochip_add(&bgc->gc);
328}
329
330static int __devinit ep93xx_gpio_probe(struct platform_device *pdev)
331{
332 struct ep93xx_gpio *ep93xx_gpio;
333 struct resource *res;
334 void __iomem *mmio;
335 int i;
336 int ret;
337
338 ep93xx_gpio = kzalloc(sizeof(*ep93xx_gpio), GFP_KERNEL);
339 if (!ep93xx_gpio)
340 return -ENOMEM;
341
342 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
343 if (!res) {
344 ret = -ENXIO;
345 goto exit_free;
346 }
347
348 if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
349 ret = -EBUSY;
350 goto exit_free;
351 }
352
353 mmio = ioremap(res->start, resource_size(res));
354 if (!mmio) {
355 ret = -ENXIO;
356 goto exit_release;
357 }
358 ep93xx_gpio->mmio_base = mmio;
359
360 /* Default all ports to GPIO */
361 ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_KEYS |
362 EP93XX_SYSCON_DEVCFG_GONK |
363 EP93XX_SYSCON_DEVCFG_EONIDE |
364 EP93XX_SYSCON_DEVCFG_GONIDE |
365 EP93XX_SYSCON_DEVCFG_HONIDE);
366
367 for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
368 struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i];
369 struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
370
371 if (ep93xx_gpio_add_bank(bgc, &pdev->dev, mmio, bank))
372 dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
373 bank->label);
374 }
375
376 ep93xx_gpio_init_irq();
377
378 return 0;
379
380exit_release:
381 release_mem_region(res->start, resource_size(res));
382exit_free:
383 kfree(ep93xx_gpio);
384 dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, ret);
385 return ret;
386}
387
388static struct platform_driver ep93xx_gpio_driver = {
389 .driver = {
390 .name = "gpio-ep93xx",
391 .owner = THIS_MODULE,
392 },
393 .probe = ep93xx_gpio_probe,
394};
395
396static int __init ep93xx_gpio_init(void)
397{
398 return platform_driver_register(&ep93xx_gpio_driver);
399}
400postcore_initcall(ep93xx_gpio_init);
401
402MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
403 "H Hartley Sweeten <hsweeten@visionengravers.com>");
404MODULE_DESCRIPTION("EP93XX GPIO driver");
405MODULE_LICENSE("GPL");