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Vivien Didelot759f5f32012-12-07 21:36:34 -05001/*
2 * Digital I/O driver for Technologic Systems TS-5500
3 *
4 * Copyright (c) 2012 Savoir-faire Linux Inc.
5 * Vivien Didelot <vivien.didelot@savoirfairelinux.com>
6 *
7 * Technologic Systems platforms have pin blocks, exposing several Digital
8 * Input/Output lines (DIO). This driver aims to support single pin blocks.
9 * In that sense, the support is not limited to the TS-5500 blocks.
10 * Actually, the following platforms have DIO support:
11 *
12 * TS-5500:
13 * Documentation: http://wiki.embeddedarm.com/wiki/TS-5500
14 * Blocks: DIO1, DIO2 and LCD port.
15 *
16 * TS-5600:
17 * Documentation: http://wiki.embeddedarm.com/wiki/TS-5600
18 * Blocks: LCD port (identical to TS-5500 LCD).
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License version 2 as
22 * published by the Free Software Foundation.
23 */
24
25#include <linux/bitops.h>
26#include <linux/gpio.h>
27#include <linux/io.h>
28#include <linux/module.h>
29#include <linux/platform_data/gpio-ts5500.h>
30#include <linux/platform_device.h>
31#include <linux/slab.h>
32
33/* List of supported Technologic Systems platforms DIO blocks */
34enum ts5500_blocks { TS5500_DIO1, TS5500_DIO2, TS5500_LCD, TS5600_LCD };
35
36struct ts5500_priv {
37 const struct ts5500_dio *pinout;
38 struct gpio_chip gpio_chip;
39 spinlock_t lock;
40 bool strap;
41 u8 hwirq;
42};
43
44/*
45 * Hex 7D is used to control several blocks (e.g. DIO2 and LCD port).
46 * This flag ensures that the region has been requested by this driver.
47 */
48static bool hex7d_reserved;
49
50/*
51 * This structure is used to describe capabilities of DIO lines,
52 * such as available directions and connected interrupt (if any).
53 */
54struct ts5500_dio {
55 const u8 value_addr;
56 const u8 value_mask;
57 const u8 control_addr;
58 const u8 control_mask;
59 const bool no_input;
60 const bool no_output;
61 const u8 irq;
62};
63
64#define TS5500_DIO_IN_OUT(vaddr, vbit, caddr, cbit) \
65 { \
66 .value_addr = vaddr, \
67 .value_mask = BIT(vbit), \
68 .control_addr = caddr, \
69 .control_mask = BIT(cbit), \
70 }
71
72#define TS5500_DIO_IN(addr, bit) \
73 { \
74 .value_addr = addr, \
75 .value_mask = BIT(bit), \
76 .no_output = true, \
77 }
78
79#define TS5500_DIO_IN_IRQ(addr, bit, _irq) \
80 { \
81 .value_addr = addr, \
82 .value_mask = BIT(bit), \
83 .no_output = true, \
84 .irq = _irq, \
85 }
86
87#define TS5500_DIO_OUT(addr, bit) \
88 { \
89 .value_addr = addr, \
90 .value_mask = BIT(bit), \
91 .no_input = true, \
92 }
93
94/*
95 * Input/Output DIO lines are programmed in groups of 4. Their values are
96 * available through 4 consecutive bits in a value port, whereas the direction
97 * of these 4 lines is driven by only 1 bit in a control port.
98 */
99#define TS5500_DIO_GROUP(vaddr, vbitfrom, caddr, cbit) \
100 TS5500_DIO_IN_OUT(vaddr, vbitfrom + 0, caddr, cbit), \
101 TS5500_DIO_IN_OUT(vaddr, vbitfrom + 1, caddr, cbit), \
102 TS5500_DIO_IN_OUT(vaddr, vbitfrom + 2, caddr, cbit), \
103 TS5500_DIO_IN_OUT(vaddr, vbitfrom + 3, caddr, cbit)
104
105/*
106 * TS-5500 DIO1 block
107 *
108 * value control dir hw
109 * addr bit addr bit in out irq name pin offset
110 *
111 * 0x7b 0 0x7a 0 x x DIO1_0 1 0
112 * 0x7b 1 0x7a 0 x x DIO1_1 3 1
113 * 0x7b 2 0x7a 0 x x DIO1_2 5 2
114 * 0x7b 3 0x7a 0 x x DIO1_3 7 3
115 * 0x7b 4 0x7a 1 x x DIO1_4 9 4
116 * 0x7b 5 0x7a 1 x x DIO1_5 11 5
117 * 0x7b 6 0x7a 1 x x DIO1_6 13 6
118 * 0x7b 7 0x7a 1 x x DIO1_7 15 7
119 * 0x7c 0 0x7a 5 x x DIO1_8 4 8
120 * 0x7c 1 0x7a 5 x x DIO1_9 6 9
121 * 0x7c 2 0x7a 5 x x DIO1_10 8 10
122 * 0x7c 3 0x7a 5 x x DIO1_11 10 11
123 * 0x7c 4 x DIO1_12 12 12
124 * 0x7c 5 x 7 DIO1_13 14 13
125 */
126static const struct ts5500_dio ts5500_dio1[] = {
127 TS5500_DIO_GROUP(0x7b, 0, 0x7a, 0),
128 TS5500_DIO_GROUP(0x7b, 4, 0x7a, 1),
129 TS5500_DIO_GROUP(0x7c, 0, 0x7a, 5),
130 TS5500_DIO_IN(0x7c, 4),
131 TS5500_DIO_IN_IRQ(0x7c, 5, 7),
132};
133
134/*
135 * TS-5500 DIO2 block
136 *
137 * value control dir hw
138 * addr bit addr bit in out irq name pin offset
139 *
140 * 0x7e 0 0x7d 0 x x DIO2_0 1 0
141 * 0x7e 1 0x7d 0 x x DIO2_1 3 1
142 * 0x7e 2 0x7d 0 x x DIO2_2 5 2
143 * 0x7e 3 0x7d 0 x x DIO2_3 7 3
144 * 0x7e 4 0x7d 1 x x DIO2_4 9 4
145 * 0x7e 5 0x7d 1 x x DIO2_5 11 5
146 * 0x7e 6 0x7d 1 x x DIO2_6 13 6
147 * 0x7e 7 0x7d 1 x x DIO2_7 15 7
148 * 0x7f 0 0x7d 5 x x DIO2_8 4 8
149 * 0x7f 1 0x7d 5 x x DIO2_9 6 9
150 * 0x7f 2 0x7d 5 x x DIO2_10 8 10
151 * 0x7f 3 0x7d 5 x x DIO2_11 10 11
152 * 0x7f 4 x 6 DIO2_13 14 12
153 */
154static const struct ts5500_dio ts5500_dio2[] = {
155 TS5500_DIO_GROUP(0x7e, 0, 0x7d, 0),
156 TS5500_DIO_GROUP(0x7e, 4, 0x7d, 1),
157 TS5500_DIO_GROUP(0x7f, 0, 0x7d, 5),
158 TS5500_DIO_IN_IRQ(0x7f, 4, 6),
159};
160
161/*
162 * TS-5500 LCD port used as DIO block
163 * TS-5600 LCD port is identical
164 *
165 * value control dir hw
166 * addr bit addr bit in out irq name pin offset
167 *
168 * 0x72 0 0x7d 2 x x LCD_0 8 0
169 * 0x72 1 0x7d 2 x x LCD_1 7 1
170 * 0x72 2 0x7d 2 x x LCD_2 10 2
171 * 0x72 3 0x7d 2 x x LCD_3 9 3
172 * 0x72 4 0x7d 3 x x LCD_4 12 4
173 * 0x72 5 0x7d 3 x x LCD_5 11 5
174 * 0x72 6 0x7d 3 x x LCD_6 14 6
175 * 0x72 7 0x7d 3 x x LCD_7 13 7
176 * 0x73 0 x LCD_EN 5 8
177 * 0x73 6 x LCD_WR 6 9
178 * 0x73 7 x 1 LCD_RS 3 10
179 */
180static const struct ts5500_dio ts5500_lcd[] = {
181 TS5500_DIO_GROUP(0x72, 0, 0x7d, 2),
182 TS5500_DIO_GROUP(0x72, 4, 0x7d, 3),
183 TS5500_DIO_OUT(0x73, 0),
184 TS5500_DIO_IN(0x73, 6),
185 TS5500_DIO_IN_IRQ(0x73, 7, 1),
186};
187
188static inline struct ts5500_priv *ts5500_gc_to_priv(struct gpio_chip *chip)
189{
190 return container_of(chip, struct ts5500_priv, gpio_chip);
191}
192
193static inline void ts5500_set_mask(u8 mask, u8 addr)
194{
195 u8 val = inb(addr);
196 val |= mask;
197 outb(val, addr);
198}
199
200static inline void ts5500_clear_mask(u8 mask, u8 addr)
201{
202 u8 val = inb(addr);
203 val &= ~mask;
204 outb(val, addr);
205}
206
207static int ts5500_gpio_input(struct gpio_chip *chip, unsigned offset)
208{
209 struct ts5500_priv *priv = ts5500_gc_to_priv(chip);
210 const struct ts5500_dio line = priv->pinout[offset];
211 unsigned long flags;
212
213 if (line.no_input)
214 return -ENXIO;
215
216 if (line.no_output)
217 return 0;
218
219 spin_lock_irqsave(&priv->lock, flags);
220 ts5500_clear_mask(line.control_mask, line.control_addr);
221 spin_unlock_irqrestore(&priv->lock, flags);
222
223 return 0;
224}
225
226static int ts5500_gpio_get(struct gpio_chip *chip, unsigned offset)
227{
228 struct ts5500_priv *priv = ts5500_gc_to_priv(chip);
229 const struct ts5500_dio line = priv->pinout[offset];
230
231 return !!(inb(line.value_addr) & line.value_mask);
232}
233
234static int ts5500_gpio_output(struct gpio_chip *chip, unsigned offset, int val)
235{
236 struct ts5500_priv *priv = ts5500_gc_to_priv(chip);
237 const struct ts5500_dio line = priv->pinout[offset];
238 unsigned long flags;
239
240 if (line.no_output)
241 return -ENXIO;
242
243 spin_lock_irqsave(&priv->lock, flags);
244 if (!line.no_input)
245 ts5500_set_mask(line.control_mask, line.control_addr);
246
247 if (val)
248 ts5500_set_mask(line.value_mask, line.value_addr);
249 else
250 ts5500_clear_mask(line.value_mask, line.value_addr);
251 spin_unlock_irqrestore(&priv->lock, flags);
252
253 return 0;
254}
255
256static void ts5500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
257{
258 struct ts5500_priv *priv = ts5500_gc_to_priv(chip);
259 const struct ts5500_dio line = priv->pinout[offset];
260 unsigned long flags;
261
262 spin_lock_irqsave(&priv->lock, flags);
263 if (val)
264 ts5500_set_mask(line.value_mask, line.value_addr);
265 else
266 ts5500_clear_mask(line.value_mask, line.value_addr);
267 spin_unlock_irqrestore(&priv->lock, flags);
268}
269
270static int ts5500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
271{
272 struct ts5500_priv *priv = ts5500_gc_to_priv(chip);
273 const struct ts5500_dio *block = priv->pinout;
274 const struct ts5500_dio line = block[offset];
275
276 /* Only one pin is connected to an interrupt */
277 if (line.irq)
278 return line.irq;
279
280 /* As this pin is input-only, we may strap it to another in/out pin */
281 if (priv->strap)
282 return priv->hwirq;
283
284 return -ENXIO;
285}
286
287static int ts5500_enable_irq(struct ts5500_priv *priv)
288{
289 int ret = 0;
290 unsigned long flags;
291
292 spin_lock_irqsave(&priv->lock, flags);
293 if (priv->hwirq == 7)
294 ts5500_set_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
295 else if (priv->hwirq == 6)
296 ts5500_set_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
297 else if (priv->hwirq == 1)
298 ts5500_set_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
299 else
300 ret = -EINVAL;
301 spin_unlock_irqrestore(&priv->lock, flags);
302
303 return ret;
304}
305
306static void ts5500_disable_irq(struct ts5500_priv *priv)
307{
308 unsigned long flags;
309
310 spin_lock_irqsave(&priv->lock, flags);
311 if (priv->hwirq == 7)
312 ts5500_clear_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
313 else if (priv->hwirq == 6)
314 ts5500_clear_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
315 else if (priv->hwirq == 1)
316 ts5500_clear_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
317 else
318 dev_err(priv->gpio_chip.dev, "invalid hwirq %d\n", priv->hwirq);
319 spin_unlock_irqrestore(&priv->lock, flags);
320}
321
322static int __devinit ts5500_dio_probe(struct platform_device *pdev)
323{
324 enum ts5500_blocks block = platform_get_device_id(pdev)->driver_data;
325 struct ts5500_dio_platform_data *pdata = pdev->dev.platform_data;
326 struct device *dev = &pdev->dev;
327 const char *name = dev_name(dev);
328 struct ts5500_priv *priv;
329 struct resource *res;
330 unsigned long flags;
331 int ret;
332
333 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
334 if (!res) {
335 dev_err(dev, "missing IRQ resource\n");
336 return -EINVAL;
337 }
338
339 priv = devm_kzalloc(dev, sizeof(struct ts5500_priv), GFP_KERNEL);
340 if (!priv)
341 return -ENOMEM;
342
343 platform_set_drvdata(pdev, priv);
344 priv->hwirq = res->start;
345 spin_lock_init(&priv->lock);
346
347 priv->gpio_chip.owner = THIS_MODULE;
348 priv->gpio_chip.label = name;
349 priv->gpio_chip.dev = dev;
350 priv->gpio_chip.direction_input = ts5500_gpio_input;
351 priv->gpio_chip.direction_output = ts5500_gpio_output;
352 priv->gpio_chip.get = ts5500_gpio_get;
353 priv->gpio_chip.set = ts5500_gpio_set;
354 priv->gpio_chip.to_irq = ts5500_gpio_to_irq;
355 priv->gpio_chip.base = -1;
356 if (pdata) {
357 priv->gpio_chip.base = pdata->base;
358 priv->strap = pdata->strap;
359 }
360
361 switch (block) {
362 case TS5500_DIO1:
363 priv->pinout = ts5500_dio1;
364 priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio1);
365
366 if (!devm_request_region(dev, 0x7a, 3, name)) {
367 dev_err(dev, "failed to request %s ports\n", name);
368 return -EBUSY;
369 }
370 break;
371 case TS5500_DIO2:
372 priv->pinout = ts5500_dio2;
373 priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio2);
374
375 if (!devm_request_region(dev, 0x7e, 2, name)) {
376 dev_err(dev, "failed to request %s ports\n", name);
377 return -EBUSY;
378 }
379
380 if (hex7d_reserved)
381 break;
382
383 if (!devm_request_region(dev, 0x7d, 1, name)) {
384 dev_err(dev, "failed to request %s 7D\n", name);
385 return -EBUSY;
386 }
387
388 hex7d_reserved = true;
389 break;
390 case TS5500_LCD:
391 case TS5600_LCD:
392 priv->pinout = ts5500_lcd;
393 priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_lcd);
394
395 if (!devm_request_region(dev, 0x72, 2, name)) {
396 dev_err(dev, "failed to request %s ports\n", name);
397 return -EBUSY;
398 }
399
400 if (!hex7d_reserved) {
401 if (!devm_request_region(dev, 0x7d, 1, name)) {
402 dev_err(dev, "failed to request %s 7D\n", name);
403 return -EBUSY;
404 }
405
406 hex7d_reserved = true;
407 }
408
409 /* Ensure usage of LCD port as DIO */
410 spin_lock_irqsave(&priv->lock, flags);
411 ts5500_clear_mask(BIT(4), 0x7d);
412 spin_unlock_irqrestore(&priv->lock, flags);
413 break;
414 }
415
416 ret = gpiochip_add(&priv->gpio_chip);
417 if (ret) {
418 dev_err(dev, "failed to register the gpio chip\n");
419 return ret;
420 }
421
422 ret = ts5500_enable_irq(priv);
423 if (ret) {
424 dev_err(dev, "invalid interrupt %d\n", priv->hwirq);
425 goto cleanup;
426 }
427
428 return 0;
429cleanup:
430 if (gpiochip_remove(&priv->gpio_chip))
431 dev_err(dev, "failed to remove gpio chip\n");
432 return ret;
433}
434
435static int __devexit ts5500_dio_remove(struct platform_device *pdev)
436{
437 struct ts5500_priv *priv = platform_get_drvdata(pdev);
438
439 ts5500_disable_irq(priv);
440 return gpiochip_remove(&priv->gpio_chip);
441}
442
443static struct platform_device_id ts5500_dio_ids[] = {
444 { "ts5500-dio1", TS5500_DIO1 },
445 { "ts5500-dio2", TS5500_DIO2 },
446 { "ts5500-dio-lcd", TS5500_LCD },
447 { "ts5600-dio-lcd", TS5600_LCD },
448 { }
449};
450MODULE_DEVICE_TABLE(platform, ts5500_dio_ids);
451
452static struct platform_driver ts5500_dio_driver = {
453 .driver = {
454 .name = "ts5500-dio",
455 .owner = THIS_MODULE,
456 },
457 .probe = ts5500_dio_probe,
458 .remove = __devexit_p(ts5500_dio_remove),
459 .id_table = ts5500_dio_ids,
460};
461
462module_platform_driver(ts5500_dio_driver);
463
464MODULE_LICENSE("GPL");
465MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
466MODULE_DESCRIPTION("Technologic Systems TS-5500 Digital I/O driver");