1 /*
2 * Emma Mobile GPIO Support - GIO
3 *
4 * Copyright (C) 2012 Magnus Damm
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/init.h>
21 #include <linux/platform_device.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/io.h>
26 #include <linux/irq.h>
27 #include <linux/irqdomain.h>
28 #include <linux/bitops.h>
29 #include <linux/err.h>
30 #include <linux/gpio/driver.h>
31 #include <linux/slab.h>
32 #include <linux/module.h>
33 #include <linux/pinctrl/consumer.h>
34
35 struct em_gio_priv {
36 void __iomem *base0;
37 void __iomem *base1;
38 spinlock_t sense_lock;
39 struct platform_device *pdev;
40 struct gpio_chip gpio_chip;
41 struct irq_chip irq_chip;
42 struct irq_domain *irq_domain;
43 };
44
45 #define GIO_E1 0x00
46 #define GIO_E0 0x04
47 #define GIO_EM 0x04
48 #define GIO_OL 0x08
49 #define GIO_OH 0x0c
50 #define GIO_I 0x10
51 #define GIO_IIA 0x14
52 #define GIO_IEN 0x18
53 #define GIO_IDS 0x1c
54 #define GIO_IIM 0x1c
55 #define GIO_RAW 0x20
56 #define GIO_MST 0x24
57 #define GIO_IIR 0x28
58
59 #define GIO_IDT0 0x40
60 #define GIO_IDT1 0x44
61 #define GIO_IDT2 0x48
62 #define GIO_IDT3 0x4c
63 #define GIO_RAWBL 0x50
64 #define GIO_RAWBH 0x54
65 #define GIO_IRBL 0x58
66 #define GIO_IRBH 0x5c
67
68 #define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))
69
em_gio_read(struct em_gio_priv * p,int offs)70 static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
71 {
72 if (offs < GIO_IDT0)
73 return ioread32(p->base0 + offs);
74 else
75 return ioread32(p->base1 + (offs - GIO_IDT0));
76 }
77
em_gio_write(struct em_gio_priv * p,int offs,unsigned long value)78 static inline void em_gio_write(struct em_gio_priv *p, int offs,
79 unsigned long value)
80 {
81 if (offs < GIO_IDT0)
82 iowrite32(value, p->base0 + offs);
83 else
84 iowrite32(value, p->base1 + (offs - GIO_IDT0));
85 }
86
em_gio_irq_disable(struct irq_data * d)87 static void em_gio_irq_disable(struct irq_data *d)
88 {
89 struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
90
91 em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
92 }
93
em_gio_irq_enable(struct irq_data * d)94 static void em_gio_irq_enable(struct irq_data *d)
95 {
96 struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
97
98 em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
99 }
100
em_gio_irq_reqres(struct irq_data * d)101 static int em_gio_irq_reqres(struct irq_data *d)
102 {
103 struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
104 int ret;
105
106 ret = gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
107 if (ret) {
108 dev_err(p->gpio_chip.parent,
109 "unable to lock HW IRQ %lu for IRQ\n",
110 irqd_to_hwirq(d));
111 return ret;
112 }
113 return 0;
114 }
115
em_gio_irq_relres(struct irq_data * d)116 static void em_gio_irq_relres(struct irq_data *d)
117 {
118 struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
119
120 gpiochip_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
121 }
122
123
124 #define GIO_ASYNC(x) (x + 8)
125
126 static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
127 [IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
128 [IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
129 [IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
130 [IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
131 [IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
132 };
133
em_gio_irq_set_type(struct irq_data * d,unsigned int type)134 static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
135 {
136 unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
137 struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
138 unsigned int reg, offset, shift;
139 unsigned long flags;
140 unsigned long tmp;
141
142 if (!value)
143 return -EINVAL;
144
145 offset = irqd_to_hwirq(d);
146
147 pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
148
149 /* 8 x 4 bit fields in 4 IDT registers */
150 reg = GIO_IDT(offset >> 3);
151 shift = (offset & 0x07) << 4;
152
153 spin_lock_irqsave(&p->sense_lock, flags);
154
155 /* disable the interrupt in IIA */
156 tmp = em_gio_read(p, GIO_IIA);
157 tmp &= ~BIT(offset);
158 em_gio_write(p, GIO_IIA, tmp);
159
160 /* change the sense setting in IDT */
161 tmp = em_gio_read(p, reg);
162 tmp &= ~(0xf << shift);
163 tmp |= value << shift;
164 em_gio_write(p, reg, tmp);
165
166 /* clear pending interrupts */
167 em_gio_write(p, GIO_IIR, BIT(offset));
168
169 /* enable the interrupt in IIA */
170 tmp = em_gio_read(p, GIO_IIA);
171 tmp |= BIT(offset);
172 em_gio_write(p, GIO_IIA, tmp);
173
174 spin_unlock_irqrestore(&p->sense_lock, flags);
175
176 return 0;
177 }
178
em_gio_irq_handler(int irq,void * dev_id)179 static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
180 {
181 struct em_gio_priv *p = dev_id;
182 unsigned long pending;
183 unsigned int offset, irqs_handled = 0;
184
185 while ((pending = em_gio_read(p, GIO_MST))) {
186 offset = __ffs(pending);
187 em_gio_write(p, GIO_IIR, BIT(offset));
188 generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
189 irqs_handled++;
190 }
191
192 return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
193 }
194
gpio_to_priv(struct gpio_chip * chip)195 static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
196 {
197 return gpiochip_get_data(chip);
198 }
199
em_gio_direction_input(struct gpio_chip * chip,unsigned offset)200 static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
201 {
202 em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
203 return 0;
204 }
205
em_gio_get(struct gpio_chip * chip,unsigned offset)206 static int em_gio_get(struct gpio_chip *chip, unsigned offset)
207 {
208 return !!(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
209 }
210
__em_gio_set(struct gpio_chip * chip,unsigned int reg,unsigned shift,int value)211 static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
212 unsigned shift, int value)
213 {
214 /* upper 16 bits contains mask and lower 16 actual value */
215 em_gio_write(gpio_to_priv(chip), reg,
216 (BIT(shift + 16)) | (value << shift));
217 }
218
em_gio_set(struct gpio_chip * chip,unsigned offset,int value)219 static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
220 {
221 /* output is split into two registers */
222 if (offset < 16)
223 __em_gio_set(chip, GIO_OL, offset, value);
224 else
225 __em_gio_set(chip, GIO_OH, offset - 16, value);
226 }
227
em_gio_direction_output(struct gpio_chip * chip,unsigned offset,int value)228 static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
229 int value)
230 {
231 /* write GPIO value to output before selecting output mode of pin */
232 em_gio_set(chip, offset, value);
233 em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
234 return 0;
235 }
236
em_gio_to_irq(struct gpio_chip * chip,unsigned offset)237 static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
238 {
239 return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
240 }
241
em_gio_request(struct gpio_chip * chip,unsigned offset)242 static int em_gio_request(struct gpio_chip *chip, unsigned offset)
243 {
244 return pinctrl_gpio_request(chip->base + offset);
245 }
246
em_gio_free(struct gpio_chip * chip,unsigned offset)247 static void em_gio_free(struct gpio_chip *chip, unsigned offset)
248 {
249 pinctrl_gpio_free(chip->base + offset);
250
251 /* Set the GPIO as an input to ensure that the next GPIO request won't
252 * drive the GPIO pin as an output.
253 */
254 em_gio_direction_input(chip, offset);
255 }
256
em_gio_irq_domain_map(struct irq_domain * h,unsigned int irq,irq_hw_number_t hwirq)257 static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int irq,
258 irq_hw_number_t hwirq)
259 {
260 struct em_gio_priv *p = h->host_data;
261
262 pr_debug("gio: map hw irq = %d, irq = %d\n", (int)hwirq, irq);
263
264 irq_set_chip_data(irq, h->host_data);
265 irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
266 return 0;
267 }
268
269 static const struct irq_domain_ops em_gio_irq_domain_ops = {
270 .map = em_gio_irq_domain_map,
271 .xlate = irq_domain_xlate_twocell,
272 };
273
em_gio_probe(struct platform_device * pdev)274 static int em_gio_probe(struct platform_device *pdev)
275 {
276 struct em_gio_priv *p;
277 struct resource *io[2], *irq[2];
278 struct gpio_chip *gpio_chip;
279 struct irq_chip *irq_chip;
280 const char *name = dev_name(&pdev->dev);
281 unsigned int ngpios;
282 int ret;
283
284 p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
285 if (!p) {
286 ret = -ENOMEM;
287 goto err0;
288 }
289
290 p->pdev = pdev;
291 platform_set_drvdata(pdev, p);
292 spin_lock_init(&p->sense_lock);
293
294 io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
295 io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
296 irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
297 irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
298
299 if (!io[0] || !io[1] || !irq[0] || !irq[1]) {
300 dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
301 ret = -EINVAL;
302 goto err0;
303 }
304
305 p->base0 = devm_ioremap_nocache(&pdev->dev, io[0]->start,
306 resource_size(io[0]));
307 if (!p->base0) {
308 dev_err(&pdev->dev, "failed to remap low I/O memory\n");
309 ret = -ENXIO;
310 goto err0;
311 }
312
313 p->base1 = devm_ioremap_nocache(&pdev->dev, io[1]->start,
314 resource_size(io[1]));
315 if (!p->base1) {
316 dev_err(&pdev->dev, "failed to remap high I/O memory\n");
317 ret = -ENXIO;
318 goto err0;
319 }
320
321 if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
322 dev_err(&pdev->dev, "Missing ngpios OF property\n");
323 ret = -EINVAL;
324 goto err0;
325 }
326
327 gpio_chip = &p->gpio_chip;
328 gpio_chip->of_node = pdev->dev.of_node;
329 gpio_chip->direction_input = em_gio_direction_input;
330 gpio_chip->get = em_gio_get;
331 gpio_chip->direction_output = em_gio_direction_output;
332 gpio_chip->set = em_gio_set;
333 gpio_chip->to_irq = em_gio_to_irq;
334 gpio_chip->request = em_gio_request;
335 gpio_chip->free = em_gio_free;
336 gpio_chip->label = name;
337 gpio_chip->parent = &pdev->dev;
338 gpio_chip->owner = THIS_MODULE;
339 gpio_chip->base = -1;
340 gpio_chip->ngpio = ngpios;
341
342 irq_chip = &p->irq_chip;
343 irq_chip->name = name;
344 irq_chip->irq_mask = em_gio_irq_disable;
345 irq_chip->irq_unmask = em_gio_irq_enable;
346 irq_chip->irq_set_type = em_gio_irq_set_type;
347 irq_chip->irq_request_resources = em_gio_irq_reqres;
348 irq_chip->irq_release_resources = em_gio_irq_relres;
349 irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;
350
351 p->irq_domain = irq_domain_add_simple(pdev->dev.of_node, ngpios, 0,
352 &em_gio_irq_domain_ops, p);
353 if (!p->irq_domain) {
354 ret = -ENXIO;
355 dev_err(&pdev->dev, "cannot initialize irq domain\n");
356 goto err0;
357 }
358
359 if (devm_request_irq(&pdev->dev, irq[0]->start,
360 em_gio_irq_handler, 0, name, p)) {
361 dev_err(&pdev->dev, "failed to request low IRQ\n");
362 ret = -ENOENT;
363 goto err1;
364 }
365
366 if (devm_request_irq(&pdev->dev, irq[1]->start,
367 em_gio_irq_handler, 0, name, p)) {
368 dev_err(&pdev->dev, "failed to request high IRQ\n");
369 ret = -ENOENT;
370 goto err1;
371 }
372
373 ret = gpiochip_add_data(gpio_chip, p);
374 if (ret) {
375 dev_err(&pdev->dev, "failed to add GPIO controller\n");
376 goto err1;
377 }
378
379 return 0;
380
381 err1:
382 irq_domain_remove(p->irq_domain);
383 err0:
384 return ret;
385 }
386
em_gio_remove(struct platform_device * pdev)387 static int em_gio_remove(struct platform_device *pdev)
388 {
389 struct em_gio_priv *p = platform_get_drvdata(pdev);
390
391 gpiochip_remove(&p->gpio_chip);
392
393 irq_domain_remove(p->irq_domain);
394 return 0;
395 }
396
397 static const struct of_device_id em_gio_dt_ids[] = {
398 { .compatible = "renesas,em-gio", },
399 {},
400 };
401 MODULE_DEVICE_TABLE(of, em_gio_dt_ids);
402
403 static struct platform_driver em_gio_device_driver = {
404 .probe = em_gio_probe,
405 .remove = em_gio_remove,
406 .driver = {
407 .name = "em_gio",
408 .of_match_table = em_gio_dt_ids,
409 }
410 };
411
em_gio_init(void)412 static int __init em_gio_init(void)
413 {
414 return platform_driver_register(&em_gio_device_driver);
415 }
416 postcore_initcall(em_gio_init);
417
em_gio_exit(void)418 static void __exit em_gio_exit(void)
419 {
420 platform_driver_unregister(&em_gio_device_driver);
421 }
422 module_exit(em_gio_exit);
423
424 MODULE_AUTHOR("Magnus Damm");
425 MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
426 MODULE_LICENSE("GPL v2");
427
