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Tien Hock Lohc5abbba2015-02-24 01:53:03 -08001/*
2 * Copyright (C) 2013 Altera Corporation
3 * Based on gpio-mpc8xxx.c
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
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, see <http://www.gnu.org/licenses/>.
17 */
18
19#include <linux/io.h>
20#include <linux/of_gpio.h>
21#include <linux/platform_device.h>
22
23#define ALTERA_GPIO_MAX_NGPIO 32
24#define ALTERA_GPIO_DATA 0x0
25#define ALTERA_GPIO_DIR 0x4
26#define ALTERA_GPIO_IRQ_MASK 0x8
27#define ALTERA_GPIO_EDGE_CAP 0xc
28
29/**
30* struct altera_gpio_chip
31* @mmchip : memory mapped chip structure.
32* @gpio_lock : synchronization lock so that new irq/set/get requests
33 will be blocked until the current one completes.
34* @interrupt_trigger : specifies the hardware configured IRQ trigger type
35 (rising, falling, both, high)
36* @mapped_irq : kernel mapped irq number.
37*/
38struct altera_gpio_chip {
39 struct of_mm_gpio_chip mmchip;
40 spinlock_t gpio_lock;
41 int interrupt_trigger;
42 int mapped_irq;
43};
44
Linus Walleij231d51b2015-08-25 10:54:12 +020045static struct altera_gpio_chip *to_altera(struct gpio_chip *gc)
46{
47 return container_of(gc, struct altera_gpio_chip, mmchip.gc);
48}
49
Tien Hock Lohc5abbba2015-02-24 01:53:03 -080050static void altera_gpio_irq_unmask(struct irq_data *d)
51{
52 struct altera_gpio_chip *altera_gc;
53 struct of_mm_gpio_chip *mm_gc;
54 unsigned long flags;
55 u32 intmask;
56
Linus Walleij231d51b2015-08-25 10:54:12 +020057 altera_gc = to_altera(irq_data_get_irq_chip_data(d));
Tien Hock Lohc5abbba2015-02-24 01:53:03 -080058 mm_gc = &altera_gc->mmchip;
59
60 spin_lock_irqsave(&altera_gc->gpio_lock, flags);
61 intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
62 /* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
63 intmask |= BIT(irqd_to_hwirq(d));
64 writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
65 spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
66}
67
68static void altera_gpio_irq_mask(struct irq_data *d)
69{
70 struct altera_gpio_chip *altera_gc;
71 struct of_mm_gpio_chip *mm_gc;
72 unsigned long flags;
73 u32 intmask;
74
Linus Walleij231d51b2015-08-25 10:54:12 +020075 altera_gc = to_altera(irq_data_get_irq_chip_data(d));
Tien Hock Lohc5abbba2015-02-24 01:53:03 -080076 mm_gc = &altera_gc->mmchip;
77
78 spin_lock_irqsave(&altera_gc->gpio_lock, flags);
79 intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
80 /* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
81 intmask &= ~BIT(irqd_to_hwirq(d));
82 writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
83 spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
84}
85
86/**
87 * This controller's IRQ type is synthesized in hardware, so this function
88 * just checks if the requested set_type matches the synthesized IRQ type
89 */
90static int altera_gpio_irq_set_type(struct irq_data *d,
91 unsigned int type)
92{
93 struct altera_gpio_chip *altera_gc;
94
Linus Walleij231d51b2015-08-25 10:54:12 +020095 altera_gc = to_altera(irq_data_get_irq_chip_data(d));
Tien Hock Lohc5abbba2015-02-24 01:53:03 -080096
97 if (type == IRQ_TYPE_NONE)
98 return 0;
99 if (type == IRQ_TYPE_LEVEL_HIGH &&
100 altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH)
101 return 0;
102 if (type == IRQ_TYPE_EDGE_RISING &&
103 altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_RISING)
104 return 0;
105 if (type == IRQ_TYPE_EDGE_FALLING &&
106 altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_FALLING)
107 return 0;
108 if (type == IRQ_TYPE_EDGE_BOTH &&
109 altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_BOTH)
110 return 0;
111
112 return -EINVAL;
113}
114
Daniel Lockyer38e003f2015-06-10 14:26:27 +0100115static unsigned int altera_gpio_irq_startup(struct irq_data *d)
116{
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800117 altera_gpio_irq_unmask(d);
118
119 return 0;
120}
121
122static struct irq_chip altera_irq_chip = {
123 .name = "altera-gpio",
124 .irq_mask = altera_gpio_irq_mask,
125 .irq_unmask = altera_gpio_irq_unmask,
126 .irq_set_type = altera_gpio_irq_set_type,
127 .irq_startup = altera_gpio_irq_startup,
128 .irq_shutdown = altera_gpio_irq_mask,
129};
130
131static int altera_gpio_get(struct gpio_chip *gc, unsigned offset)
132{
133 struct of_mm_gpio_chip *mm_gc;
134
135 mm_gc = to_of_mm_gpio_chip(gc);
136
137 return !!(readl(mm_gc->regs + ALTERA_GPIO_DATA) & BIT(offset));
138}
139
140static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
141{
142 struct of_mm_gpio_chip *mm_gc;
143 struct altera_gpio_chip *chip;
144 unsigned long flags;
145 unsigned int data_reg;
146
147 mm_gc = to_of_mm_gpio_chip(gc);
148 chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
149
150 spin_lock_irqsave(&chip->gpio_lock, flags);
151 data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
152 if (value)
153 data_reg |= BIT(offset);
154 else
155 data_reg &= ~BIT(offset);
156 writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
157 spin_unlock_irqrestore(&chip->gpio_lock, flags);
158}
159
160static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
161{
162 struct of_mm_gpio_chip *mm_gc;
163 struct altera_gpio_chip *chip;
164 unsigned long flags;
165 unsigned int gpio_ddr;
166
167 mm_gc = to_of_mm_gpio_chip(gc);
168 chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
169
170 spin_lock_irqsave(&chip->gpio_lock, flags);
171 /* Set pin as input, assumes software controlled IP */
172 gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
173 gpio_ddr &= ~BIT(offset);
174 writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
175 spin_unlock_irqrestore(&chip->gpio_lock, flags);
176
177 return 0;
178}
179
180static int altera_gpio_direction_output(struct gpio_chip *gc,
181 unsigned offset, int value)
182{
183 struct of_mm_gpio_chip *mm_gc;
184 struct altera_gpio_chip *chip;
185 unsigned long flags;
186 unsigned int data_reg, gpio_ddr;
187
188 mm_gc = to_of_mm_gpio_chip(gc);
189 chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
190
191 spin_lock_irqsave(&chip->gpio_lock, flags);
192 /* Sets the GPIO value */
193 data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
194 if (value)
195 data_reg |= BIT(offset);
196 else
197 data_reg &= ~BIT(offset);
198 writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
199
200 /* Set pin as output, assumes software controlled IP */
201 gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
202 gpio_ddr |= BIT(offset);
203 writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
204 spin_unlock_irqrestore(&chip->gpio_lock, flags);
205
206 return 0;
207}
208
Thomas Gleixnerbd0b9ac2015-09-14 10:42:37 +0200209static void altera_gpio_irq_edge_handler(struct irq_desc *desc)
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800210{
211 struct altera_gpio_chip *altera_gc;
212 struct irq_chip *chip;
213 struct of_mm_gpio_chip *mm_gc;
214 struct irq_domain *irqdomain;
215 unsigned long status;
216 int i;
217
Linus Walleij231d51b2015-08-25 10:54:12 +0200218 altera_gc = to_altera(irq_desc_get_handler_data(desc));
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800219 chip = irq_desc_get_chip(desc);
220 mm_gc = &altera_gc->mmchip;
221 irqdomain = altera_gc->mmchip.gc.irqdomain;
222
223 chained_irq_enter(chip, desc);
224
225 while ((status =
226 (readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP) &
227 readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK)))) {
228 writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
229 for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
230 generic_handle_irq(irq_find_mapping(irqdomain, i));
231 }
232 }
233
234 chained_irq_exit(chip, desc);
235}
236
237
Thomas Gleixnerbd0b9ac2015-09-14 10:42:37 +0200238static void altera_gpio_irq_leveL_high_handler(struct irq_desc *desc)
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800239{
240 struct altera_gpio_chip *altera_gc;
241 struct irq_chip *chip;
242 struct of_mm_gpio_chip *mm_gc;
243 struct irq_domain *irqdomain;
244 unsigned long status;
245 int i;
246
Linus Walleij231d51b2015-08-25 10:54:12 +0200247 altera_gc = to_altera(irq_desc_get_handler_data(desc));
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800248 chip = irq_desc_get_chip(desc);
249 mm_gc = &altera_gc->mmchip;
250 irqdomain = altera_gc->mmchip.gc.irqdomain;
251
252 chained_irq_enter(chip, desc);
253
254 status = readl(mm_gc->regs + ALTERA_GPIO_DATA);
255 status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
256
257 for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
258 generic_handle_irq(irq_find_mapping(irqdomain, i));
259 }
260 chained_irq_exit(chip, desc);
261}
262
kbuild test robotc4b40492015-03-19 17:40:02 +0800263static int altera_gpio_probe(struct platform_device *pdev)
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800264{
265 struct device_node *node = pdev->dev.of_node;
266 int reg, ret;
267 struct altera_gpio_chip *altera_gc;
268
269 altera_gc = devm_kzalloc(&pdev->dev, sizeof(*altera_gc), GFP_KERNEL);
270 if (!altera_gc)
271 return -ENOMEM;
272
273 spin_lock_init(&altera_gc->gpio_lock);
274
275 if (of_property_read_u32(node, "altr,ngpio", &reg))
276 /* By default assume maximum ngpio */
277 altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
278 else
279 altera_gc->mmchip.gc.ngpio = reg;
280
281 if (altera_gc->mmchip.gc.ngpio > ALTERA_GPIO_MAX_NGPIO) {
282 dev_warn(&pdev->dev,
283 "ngpio is greater than %d, defaulting to %d\n",
284 ALTERA_GPIO_MAX_NGPIO, ALTERA_GPIO_MAX_NGPIO);
285 altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
286 }
287
288 altera_gc->mmchip.gc.direction_input = altera_gpio_direction_input;
289 altera_gc->mmchip.gc.direction_output = altera_gpio_direction_output;
290 altera_gc->mmchip.gc.get = altera_gpio_get;
291 altera_gc->mmchip.gc.set = altera_gpio_set;
292 altera_gc->mmchip.gc.owner = THIS_MODULE;
293 altera_gc->mmchip.gc.dev = &pdev->dev;
294
295 ret = of_mm_gpiochip_add(node, &altera_gc->mmchip);
296 if (ret) {
297 dev_err(&pdev->dev, "Failed adding memory mapped gpiochip\n");
298 return ret;
299 }
300
301 platform_set_drvdata(pdev, altera_gc);
302
303 altera_gc->mapped_irq = platform_get_irq(pdev, 0);
304
305 if (altera_gc->mapped_irq < 0)
306 goto skip_irq;
307
308 if (of_property_read_u32(node, "altr,interrupt-type", &reg)) {
309 ret = -EINVAL;
310 dev_err(&pdev->dev,
311 "altr,interrupt-type value not set in device tree\n");
312 goto teardown;
313 }
314 altera_gc->interrupt_trigger = reg;
315
316 ret = gpiochip_irqchip_add(&altera_gc->mmchip.gc, &altera_irq_chip, 0,
317 handle_simple_irq, IRQ_TYPE_NONE);
318
319 if (ret) {
320 dev_info(&pdev->dev, "could not add irqchip\n");
321 return ret;
322 }
323
324 gpiochip_set_chained_irqchip(&altera_gc->mmchip.gc,
325 &altera_irq_chip,
326 altera_gc->mapped_irq,
327 altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH ?
328 altera_gpio_irq_leveL_high_handler :
329 altera_gpio_irq_edge_handler);
330
331skip_irq:
332 return 0;
333teardown:
334 pr_err("%s: registration failed with status %d\n",
335 node->full_name, ret);
336
337 return ret;
338}
339
340static int altera_gpio_remove(struct platform_device *pdev)
341{
342 struct altera_gpio_chip *altera_gc = platform_get_drvdata(pdev);
343
Masahiro Yamada41ec66c2015-06-17 20:59:42 +0900344 of_mm_gpiochip_remove(&altera_gc->mmchip);
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800345
Masahiro Yamada1c8b5d62015-06-17 20:59:43 +0900346 return 0;
Tien Hock Lohc5abbba2015-02-24 01:53:03 -0800347}
348
349static const struct of_device_id altera_gpio_of_match[] = {
350 { .compatible = "altr,pio-1.0", },
351 {},
352};
353MODULE_DEVICE_TABLE(of, altera_gpio_of_match);
354
355static struct platform_driver altera_gpio_driver = {
356 .driver = {
357 .name = "altera_gpio",
358 .of_match_table = of_match_ptr(altera_gpio_of_match),
359 },
360 .probe = altera_gpio_probe,
361 .remove = altera_gpio_remove,
362};
363
364static int __init altera_gpio_init(void)
365{
366 return platform_driver_register(&altera_gpio_driver);
367}
368subsys_initcall(altera_gpio_init);
369
370static void __exit altera_gpio_exit(void)
371{
372 platform_driver_unregister(&altera_gpio_driver);
373}
374module_exit(altera_gpio_exit);
375
376MODULE_AUTHOR("Tien Hock Loh <thloh@altera.com>");
377MODULE_DESCRIPTION("Altera GPIO driver");
378MODULE_LICENSE("GPL");