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Andreas Larssonddb27f32013-04-17 14:36:50 +02001/*
2 * Driver for Aeroflex Gaisler GRGPIO General Purpose I/O cores.
3 *
4 * 2013 (c) Aeroflex Gaisler AB
5 *
6 * This driver supports the GRGPIO GPIO core available in the GRLIB VHDL
7 * IP core library.
8 *
9 * Full documentation of the GRGPIO core can be found here:
10 * http://www.gaisler.com/products/grlib/grip.pdf
11 *
12 * See "Documentation/devicetree/bindings/gpio/gpio-grgpio.txt" for
13 * information on open firmware properties.
14 *
15 * This program is free software; you can redistribute it and/or modify it
16 * under the terms of the GNU General Public License as published by the
17 * Free Software Foundation; either version 2 of the License, or (at your
18 * option) any later version.
19 *
20 * Contributors: Andreas Larsson <andreas@gaisler.com>
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/spinlock.h>
27#include <linux/io.h>
28#include <linux/of.h>
29#include <linux/of_gpio.h>
30#include <linux/of_platform.h>
31#include <linux/gpio.h>
32#include <linux/slab.h>
33#include <linux/err.h>
34#include <linux/basic_mmio_gpio.h>
Andreas Larsson08ffb222013-04-17 14:36:51 +020035#include <linux/interrupt.h>
36#include <linux/irq.h>
37#include <linux/irqdomain.h>
Andreas Larssonddb27f32013-04-17 14:36:50 +020038
39#define GRGPIO_MAX_NGPIO 32
40
41#define GRGPIO_DATA 0x00
42#define GRGPIO_OUTPUT 0x04
43#define GRGPIO_DIR 0x08
44#define GRGPIO_IMASK 0x0c
45#define GRGPIO_IPOL 0x10
46#define GRGPIO_IEDGE 0x14
47#define GRGPIO_BYPASS 0x18
48#define GRGPIO_IMAP_BASE 0x20
49
Andreas Larsson08ffb222013-04-17 14:36:51 +020050/* Structure for an irq of the core - called an underlying irq */
51struct grgpio_uirq {
52 u8 refcnt; /* Reference counter to manage requesting/freeing of uirq */
53 u8 uirq; /* Underlying irq of the gpio driver */
54};
55
56/*
57 * Structure for an irq of a gpio line handed out by this driver. The index is
58 * used to map to the corresponding underlying irq.
59 */
60struct grgpio_lirq {
61 s8 index; /* Index into struct grgpio_priv's uirqs, or -1 */
62 u8 irq; /* irq for the gpio line */
63};
64
Andreas Larssonddb27f32013-04-17 14:36:50 +020065struct grgpio_priv {
66 struct bgpio_chip bgc;
67 void __iomem *regs;
68 struct device *dev;
Andreas Larsson08ffb222013-04-17 14:36:51 +020069
70 u32 imask; /* irq mask shadow register */
71
72 /*
73 * The grgpio core can have multiple "underlying" irqs. The gpio lines
74 * can be mapped to any one or none of these underlying irqs
75 * independently of each other. This driver sets up an irq domain and
76 * hands out separate irqs to each gpio line
77 */
78 struct irq_domain *domain;
79
80 /*
81 * This array contains information on each underlying irq, each
82 * irq of the grgpio core itself.
83 */
84 struct grgpio_uirq uirqs[GRGPIO_MAX_NGPIO];
85
86 /*
87 * This array contains information for each gpio line on the irqs
88 * obtains from this driver. An index value of -1 for a certain gpio
89 * line indicates that the line has no irq. Otherwise the index connects
90 * the irq to the underlying irq by pointing into the uirqs array.
91 */
92 struct grgpio_lirq lirqs[GRGPIO_MAX_NGPIO];
Andreas Larssonddb27f32013-04-17 14:36:50 +020093};
94
95static inline struct grgpio_priv *grgpio_gc_to_priv(struct gpio_chip *gc)
96{
97 struct bgpio_chip *bgc = to_bgpio_chip(gc);
98
99 return container_of(bgc, struct grgpio_priv, bgc);
100}
101
Andreas Larsson08ffb222013-04-17 14:36:51 +0200102static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
103 int val)
104{
105 struct bgpio_chip *bgc = &priv->bgc;
106 unsigned long mask = bgc->pin2mask(bgc, offset);
107 unsigned long flags;
108
109 spin_lock_irqsave(&bgc->lock, flags);
110
111 if (val)
112 priv->imask |= mask;
113 else
114 priv->imask &= ~mask;
115 bgc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
116
117 spin_unlock_irqrestore(&bgc->lock, flags);
118}
119
120static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset)
121{
122 struct grgpio_priv *priv = grgpio_gc_to_priv(gc);
123
124 if (offset > gc->ngpio)
125 return -ENXIO;
126
127 if (priv->lirqs[offset].index < 0)
128 return -ENXIO;
129
130 return irq_create_mapping(priv->domain, offset);
131}
132
133/* -------------------- IRQ chip functions -------------------- */
134
135static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
136{
137 struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
138 unsigned long flags;
139 u32 mask = BIT(d->hwirq);
140 u32 ipol;
141 u32 iedge;
142 u32 pol;
143 u32 edge;
144
145 switch (type) {
146 case IRQ_TYPE_LEVEL_LOW:
147 pol = 0;
148 edge = 0;
149 break;
150 case IRQ_TYPE_LEVEL_HIGH:
151 pol = mask;
152 edge = 0;
153 break;
154 case IRQ_TYPE_EDGE_FALLING:
155 pol = 0;
156 edge = mask;
157 break;
158 case IRQ_TYPE_EDGE_RISING:
159 pol = mask;
160 edge = mask;
161 break;
162 default:
163 return -EINVAL;
164 }
165
166 spin_lock_irqsave(&priv->bgc.lock, flags);
167
168 ipol = priv->bgc.read_reg(priv->regs + GRGPIO_IPOL) & ~mask;
169 iedge = priv->bgc.read_reg(priv->regs + GRGPIO_IEDGE) & ~mask;
170
171 priv->bgc.write_reg(priv->regs + GRGPIO_IPOL, ipol | pol);
172 priv->bgc.write_reg(priv->regs + GRGPIO_IEDGE, iedge | edge);
173
174 spin_unlock_irqrestore(&priv->bgc.lock, flags);
175
176 return 0;
177}
178
179static void grgpio_irq_mask(struct irq_data *d)
180{
181 struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
182 int offset = d->hwirq;
183
184 grgpio_set_imask(priv, offset, 0);
185}
186
187static void grgpio_irq_unmask(struct irq_data *d)
188{
189 struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
190 int offset = d->hwirq;
191
192 grgpio_set_imask(priv, offset, 1);
193}
194
195static struct irq_chip grgpio_irq_chip = {
196 .name = "grgpio",
197 .irq_mask = grgpio_irq_mask,
198 .irq_unmask = grgpio_irq_unmask,
199 .irq_set_type = grgpio_irq_set_type,
200};
201
202static irqreturn_t grgpio_irq_handler(int irq, void *dev)
203{
204 struct grgpio_priv *priv = dev;
205 int ngpio = priv->bgc.gc.ngpio;
206 unsigned long flags;
207 int i;
208 int match = 0;
209
210 spin_lock_irqsave(&priv->bgc.lock, flags);
211
212 /*
213 * For each gpio line, call its interrupt handler if it its underlying
214 * irq matches the current irq that is handled.
215 */
216 for (i = 0; i < ngpio; i++) {
217 struct grgpio_lirq *lirq = &priv->lirqs[i];
218
219 if (priv->imask & BIT(i) && lirq->index >= 0 &&
220 priv->uirqs[lirq->index].uirq == irq) {
221 generic_handle_irq(lirq->irq);
222 match = 1;
223 }
224 }
225
226 spin_unlock_irqrestore(&priv->bgc.lock, flags);
227
228 if (!match)
229 dev_warn(priv->dev, "No gpio line matched irq %d\n", irq);
230
231 return IRQ_HANDLED;
232}
233
234/*
235 * This function will be called as a consequence of the call to
236 * irq_create_mapping in grgpio_to_irq
237 */
Sachin Kamat61e38842013-06-18 17:07:03 +0530238static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
239 irq_hw_number_t hwirq)
Andreas Larsson08ffb222013-04-17 14:36:51 +0200240{
241 struct grgpio_priv *priv = d->host_data;
242 struct grgpio_lirq *lirq;
243 struct grgpio_uirq *uirq;
244 unsigned long flags;
245 int offset = hwirq;
246 int ret = 0;
247
248 if (!priv)
249 return -EINVAL;
250
251 lirq = &priv->lirqs[offset];
252 if (lirq->index < 0)
253 return -EINVAL;
254
255 dev_dbg(priv->dev, "Mapping irq %d for gpio line %d\n",
256 irq, offset);
257
258 spin_lock_irqsave(&priv->bgc.lock, flags);
259
260 /* Request underlying irq if not already requested */
261 lirq->irq = irq;
262 uirq = &priv->uirqs[lirq->index];
263 if (uirq->refcnt == 0) {
264 ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
265 dev_name(priv->dev), priv);
266 if (ret) {
267 dev_err(priv->dev,
268 "Could not request underlying irq %d\n",
269 uirq->uirq);
270
271 spin_unlock_irqrestore(&priv->bgc.lock, flags);
272
273 return ret;
274 }
275 }
276 uirq->refcnt++;
277
278 spin_unlock_irqrestore(&priv->bgc.lock, flags);
279
280 /* Setup irq */
281 irq_set_chip_data(irq, priv);
282 irq_set_chip_and_handler(irq, &grgpio_irq_chip,
283 handle_simple_irq);
284 irq_clear_status_flags(irq, IRQ_NOREQUEST);
285#ifdef CONFIG_ARM
286 set_irq_flags(irq, IRQF_VALID);
287#else
288 irq_set_noprobe(irq);
289#endif
290
291 return ret;
292}
293
Sachin Kamat61e38842013-06-18 17:07:03 +0530294static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
Andreas Larsson08ffb222013-04-17 14:36:51 +0200295{
296 struct grgpio_priv *priv = d->host_data;
297 int index;
298 struct grgpio_lirq *lirq;
299 struct grgpio_uirq *uirq;
300 unsigned long flags;
301 int ngpio = priv->bgc.gc.ngpio;
302 int i;
303
304#ifdef CONFIG_ARM
305 set_irq_flags(irq, 0);
306#endif
307 irq_set_chip_and_handler(irq, NULL, NULL);
308 irq_set_chip_data(irq, NULL);
309
310 spin_lock_irqsave(&priv->bgc.lock, flags);
311
312 /* Free underlying irq if last user unmapped */
313 index = -1;
314 for (i = 0; i < ngpio; i++) {
315 lirq = &priv->lirqs[i];
316 if (lirq->irq == irq) {
317 grgpio_set_imask(priv, i, 0);
318 lirq->irq = 0;
319 index = lirq->index;
320 break;
321 }
322 }
323 WARN_ON(index < 0);
324
325 if (index >= 0) {
326 uirq = &priv->uirqs[lirq->index];
327 uirq->refcnt--;
328 if (uirq->refcnt == 0)
329 free_irq(uirq->uirq, priv);
330 }
331
332 spin_unlock_irqrestore(&priv->bgc.lock, flags);
333}
334
335static struct irq_domain_ops grgpio_irq_domain_ops = {
336 .map = grgpio_irq_map,
337 .unmap = grgpio_irq_unmap,
338};
339
340/* ------------------------------------------------------------ */
341
Andreas Larssonddb27f32013-04-17 14:36:50 +0200342static int grgpio_probe(struct platform_device *ofdev)
343{
344 struct device_node *np = ofdev->dev.of_node;
345 void __iomem *regs;
346 struct gpio_chip *gc;
347 struct bgpio_chip *bgc;
348 struct grgpio_priv *priv;
349 struct resource *res;
350 int err;
351 u32 prop;
Andreas Larsson08ffb222013-04-17 14:36:51 +0200352 s32 *irqmap;
353 int size;
354 int i;
Andreas Larssonddb27f32013-04-17 14:36:50 +0200355
356 priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);
357 if (!priv)
358 return -ENOMEM;
359
360 res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
361 regs = devm_ioremap_resource(&ofdev->dev, res);
362 if (IS_ERR(regs))
363 return PTR_ERR(regs);
364
365 bgc = &priv->bgc;
366 err = bgpio_init(bgc, &ofdev->dev, 4, regs + GRGPIO_DATA,
367 regs + GRGPIO_OUTPUT, NULL, regs + GRGPIO_DIR, NULL,
368 BGPIOF_BIG_ENDIAN_BYTE_ORDER);
369 if (err) {
370 dev_err(&ofdev->dev, "bgpio_init() failed\n");
371 return err;
372 }
373
374 priv->regs = regs;
Andreas Larsson08ffb222013-04-17 14:36:51 +0200375 priv->imask = bgc->read_reg(regs + GRGPIO_IMASK);
Andreas Larssonddb27f32013-04-17 14:36:50 +0200376 priv->dev = &ofdev->dev;
377
378 gc = &bgc->gc;
379 gc->of_node = np;
380 gc->owner = THIS_MODULE;
Andreas Larsson08ffb222013-04-17 14:36:51 +0200381 gc->to_irq = grgpio_to_irq;
Andreas Larssonddb27f32013-04-17 14:36:50 +0200382 gc->label = np->full_name;
383 gc->base = -1;
384
385 err = of_property_read_u32(np, "nbits", &prop);
386 if (err || prop <= 0 || prop > GRGPIO_MAX_NGPIO) {
387 gc->ngpio = GRGPIO_MAX_NGPIO;
388 dev_dbg(&ofdev->dev,
389 "No or invalid nbits property: assume %d\n", gc->ngpio);
390 } else {
391 gc->ngpio = prop;
392 }
393
Andreas Larsson08ffb222013-04-17 14:36:51 +0200394 /*
395 * The irqmap contains the index values indicating which underlying irq,
396 * if anyone, is connected to that line
397 */
398 irqmap = (s32 *)of_get_property(np, "irqmap", &size);
399 if (irqmap) {
400 if (size < gc->ngpio) {
401 dev_err(&ofdev->dev,
402 "irqmap shorter than ngpio (%d < %d)\n",
403 size, gc->ngpio);
404 return -EINVAL;
405 }
406
407 priv->domain = irq_domain_add_linear(np, gc->ngpio,
408 &grgpio_irq_domain_ops,
409 priv);
410 if (!priv->domain) {
411 dev_err(&ofdev->dev, "Could not add irq domain\n");
412 return -EINVAL;
413 }
414
415 for (i = 0; i < gc->ngpio; i++) {
416 struct grgpio_lirq *lirq;
417 int ret;
418
419 lirq = &priv->lirqs[i];
420 lirq->index = irqmap[i];
421
422 if (lirq->index < 0)
423 continue;
424
425 ret = platform_get_irq(ofdev, lirq->index);
426 if (ret <= 0) {
427 /*
428 * Continue without irq functionality for that
429 * gpio line
430 */
431 dev_err(priv->dev,
432 "Failed to get irq for offset %d\n", i);
433 continue;
434 }
435 priv->uirqs[lirq->index].uirq = ret;
436 }
437 }
438
Andreas Larssonddb27f32013-04-17 14:36:50 +0200439 platform_set_drvdata(ofdev, priv);
440
441 err = gpiochip_add(gc);
442 if (err) {
443 dev_err(&ofdev->dev, "Could not add gpiochip\n");
444 return err;
445 }
446
Andreas Larsson08ffb222013-04-17 14:36:51 +0200447 dev_info(&ofdev->dev, "regs=0x%p, base=%d, ngpio=%d, irqs=%s\n",
448 priv->regs, gc->base, gc->ngpio, priv->domain ? "on" : "off");
Andreas Larssonddb27f32013-04-17 14:36:50 +0200449
450 return 0;
451}
452
453static int grgpio_remove(struct platform_device *ofdev)
454{
455 struct grgpio_priv *priv = platform_get_drvdata(ofdev);
Andreas Larsson08ffb222013-04-17 14:36:51 +0200456 unsigned long flags;
457 int i;
458 int ret = 0;
Andreas Larssonddb27f32013-04-17 14:36:50 +0200459
Andreas Larsson08ffb222013-04-17 14:36:51 +0200460 spin_lock_irqsave(&priv->bgc.lock, flags);
461
462 if (priv->domain) {
463 for (i = 0; i < GRGPIO_MAX_NGPIO; i++) {
464 if (priv->uirqs[i].refcnt != 0) {
465 ret = -EBUSY;
466 goto out;
467 }
468 }
469 }
470
abdoulaye berthe9f5132a2014-07-12 22:30:12 +0200471 gpiochip_remove(&priv->bgc.gc);
Andreas Larsson08ffb222013-04-17 14:36:51 +0200472
473 if (priv->domain)
474 irq_domain_remove(priv->domain);
475
476out:
477 spin_unlock_irqrestore(&priv->bgc.lock, flags);
478
479 return ret;
Andreas Larssonddb27f32013-04-17 14:36:50 +0200480}
481
Jingoo Hanf77b6442014-05-07 18:03:30 +0900482static const struct of_device_id grgpio_match[] = {
Andreas Larssonddb27f32013-04-17 14:36:50 +0200483 {.name = "GAISLER_GPIO"},
484 {.name = "01_01a"},
485 {},
486};
487
488MODULE_DEVICE_TABLE(of, grgpio_match);
489
490static struct platform_driver grgpio_driver = {
491 .driver = {
492 .name = "grgpio",
493 .owner = THIS_MODULE,
494 .of_match_table = grgpio_match,
495 },
496 .probe = grgpio_probe,
497 .remove = grgpio_remove,
498};
499module_platform_driver(grgpio_driver);
500
501MODULE_AUTHOR("Aeroflex Gaisler AB.");
502MODULE_DESCRIPTION("Driver for Aeroflex Gaisler GRGPIO");
503MODULE_LICENSE("GPL");