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Christian Ruppertc6ce2b62013-10-08 14:25:22 +02001/* Abilis Systems MODULE DESCRIPTION
2 *
3 * Copyright (C) Abilis Systems 2013
4 *
5 * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
6 * Christian Ruppert <christian.ruppert@abilis.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/gpio.h>
26#include <linux/slab.h>
27#include <linux/irq.h>
28#include <linux/irqdomain.h>
29#include <linux/interrupt.h>
30#include <linux/io.h>
31#include <linux/of.h>
32#include <linux/of_platform.h>
33#include <linux/of_gpio.h>
34#include <linux/spinlock.h>
35#include <linux/bitops.h>
36#include <linux/pinctrl/consumer.h>
37
38#define TB10X_GPIO_DIR_IN (0x00000000)
39#define TB10X_GPIO_DIR_OUT (0x00000001)
40#define OFFSET_TO_REG_DDR (0x00)
41#define OFFSET_TO_REG_DATA (0x04)
42#define OFFSET_TO_REG_INT_EN (0x08)
43#define OFFSET_TO_REG_CHANGE (0x0C)
44#define OFFSET_TO_REG_WRMASK (0x10)
45#define OFFSET_TO_REG_INT_TYPE (0x14)
46
47
48/**
49 * @spinlock: used for atomic read/modify/write of registers
50 * @base: register base address
51 * @domain: IRQ domain of GPIO generated interrupts managed by this controller
52 * @irq: Interrupt line of parent interrupt controller
53 * @gc: gpio_chip structure associated to this GPIO controller
54 */
55struct tb10x_gpio {
56 spinlock_t spinlock;
57 void __iomem *base;
58 struct irq_domain *domain;
59 int irq;
60 struct gpio_chip gc;
61};
62
63static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
64{
65 return ioread32(gpio->base + offs);
66}
67
68static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
69 u32 val)
70{
71 iowrite32(val, gpio->base + offs);
72}
73
74static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
75 u32 mask, u32 val)
76{
77 u32 r;
78 unsigned long flags;
79
80 spin_lock_irqsave(&gpio->spinlock, flags);
81
82 r = tb10x_reg_read(gpio, offs);
83 r = (r & ~mask) | (val & mask);
84
85 tb10x_reg_write(gpio, offs, r);
86
87 spin_unlock_irqrestore(&gpio->spinlock, flags);
88}
89
90static inline struct tb10x_gpio *to_tb10x_gpio(struct gpio_chip *chip)
91{
92 return container_of(chip, struct tb10x_gpio, gc);
93}
94
95static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
96{
97 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
98 int mask = BIT(offset);
99 int val = TB10X_GPIO_DIR_IN << offset;
100
101 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
102
103 return 0;
104}
105
106static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
107{
108 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
109 int val;
110
111 val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);
112
113 if (val & BIT(offset))
114 return 1;
115 else
116 return 0;
117}
118
119static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
120{
121 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
122 int mask = BIT(offset);
123 int val = value << offset;
124
125 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
126}
127
128static int tb10x_gpio_direction_out(struct gpio_chip *chip,
129 unsigned offset, int value)
130{
131 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
132 int mask = BIT(offset);
133 int val = TB10X_GPIO_DIR_OUT << offset;
134
Axel Lin2e862302013-10-31 11:23:46 +0800135 tb10x_gpio_set(chip, offset, value);
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200136 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
137
138 return 0;
139}
140
141static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset)
142{
143 return pinctrl_request_gpio(chip->base + offset);
144}
145
146static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset)
147{
148 pinctrl_free_gpio(chip->base + offset);
149}
150
151static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
152{
153 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
154
155 return irq_create_mapping(tb10x_gpio->domain, offset);
156}
157
158static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
159{
160 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
161 pr_err("Only (both) edge triggered interrupts supported.\n");
162 return -EINVAL;
163 }
164
165 irqd_set_trigger_type(data, type);
166
167 return IRQ_SET_MASK_OK;
168}
169
170static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
171{
172 struct tb10x_gpio *tb10x_gpio = data;
173 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
174 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
175 const unsigned long bits = r & m;
176 int i;
177
178 for_each_set_bit(i, &bits, 32)
179 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
180
181 return IRQ_HANDLED;
182}
183
184static int tb10x_gpio_probe(struct platform_device *pdev)
185{
186 struct tb10x_gpio *tb10x_gpio;
187 struct resource *mem;
188 struct device_node *dn = pdev->dev.of_node;
189 int ret = -EBUSY;
190 u32 ngpio;
191
192 if (!dn)
193 return -EINVAL;
194
195 if (of_property_read_u32(dn, "abilis,ngpio", &ngpio))
196 return -EINVAL;
197
198 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
199 if (!mem) {
200 dev_err(&pdev->dev, "No memory resource defined.\n");
201 return -EINVAL;
202 }
203
204 tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
205 if (tb10x_gpio == NULL)
206 return -ENOMEM;
207
208 spin_lock_init(&tb10x_gpio->spinlock);
209
210 tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
Wei Yongjun9a4864c2013-10-30 11:09:15 +0800211 if (IS_ERR(tb10x_gpio->base))
212 return PTR_ERR(tb10x_gpio->base);
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200213
214 tb10x_gpio->gc.label = of_node_full_name(dn);
215 tb10x_gpio->gc.dev = &pdev->dev;
216 tb10x_gpio->gc.owner = THIS_MODULE;
217 tb10x_gpio->gc.direction_input = tb10x_gpio_direction_in;
218 tb10x_gpio->gc.get = tb10x_gpio_get;
219 tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out;
220 tb10x_gpio->gc.set = tb10x_gpio_set;
221 tb10x_gpio->gc.request = tb10x_gpio_request;
222 tb10x_gpio->gc.free = tb10x_gpio_free;
223 tb10x_gpio->gc.base = -1;
224 tb10x_gpio->gc.ngpio = ngpio;
Linus Walleij9fb1f392013-12-04 14:42:46 +0100225 tb10x_gpio->gc.can_sleep = false;
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200226
227
228 ret = gpiochip_add(&tb10x_gpio->gc);
229 if (ret < 0) {
230 dev_err(&pdev->dev, "Could not add gpiochip.\n");
231 goto fail_gpiochip_registration;
232 }
233
234 platform_set_drvdata(pdev, tb10x_gpio);
235
236 if (of_find_property(dn, "interrupt-controller", NULL)) {
237 struct irq_chip_generic *gc;
238
239 ret = platform_get_irq(pdev, 0);
240 if (ret < 0) {
241 dev_err(&pdev->dev, "No interrupt specified.\n");
242 goto fail_get_irq;
243 }
244
245 tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq;
246 tb10x_gpio->irq = ret;
247
248 ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
249 IRQF_TRIGGER_NONE | IRQF_SHARED,
250 dev_name(&pdev->dev), tb10x_gpio);
251 if (ret != 0)
252 goto fail_request_irq;
253
254 tb10x_gpio->domain = irq_domain_add_linear(dn,
255 tb10x_gpio->gc.ngpio,
256 &irq_generic_chip_ops, NULL);
257 if (!tb10x_gpio->domain) {
258 ret = -ENOMEM;
259 goto fail_irq_domain;
260 }
261
262 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
263 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
264 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
265 IRQ_GC_INIT_MASK_CACHE);
266 if (ret)
267 goto fail_irq_domain;
268
269 gc = tb10x_gpio->domain->gc->gc[0];
270 gc->reg_base = tb10x_gpio->base;
271 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
272 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
273 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
274 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
275 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type;
276 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE;
277 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN;
278 }
279
280 return 0;
281
282fail_irq_domain:
283fail_request_irq:
284fail_get_irq:
285 gpiochip_remove(&tb10x_gpio->gc);
286fail_gpiochip_registration:
287fail_ioremap:
288 return ret;
289}
290
291static int __exit tb10x_gpio_remove(struct platform_device *pdev)
292{
293 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
294 int ret;
295
296 if (tb10x_gpio->gc.to_irq) {
297 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
298 BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
299 kfree(tb10x_gpio->domain->gc);
300 irq_domain_remove(tb10x_gpio->domain);
301 free_irq(tb10x_gpio->irq, tb10x_gpio);
302 }
303 ret = gpiochip_remove(&tb10x_gpio->gc);
304 if (ret)
305 return ret;
306
307 return 0;
308}
309
310static const struct of_device_id tb10x_gpio_dt_ids[] = {
311 { .compatible = "abilis,tb10x-gpio" },
312 { }
313};
314MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
315
316static struct platform_driver tb10x_gpio_driver = {
317 .probe = tb10x_gpio_probe,
318 .remove = tb10x_gpio_remove,
319 .driver = {
320 .name = "tb10x-gpio",
Sachin Kamatb10b45c02013-12-21 15:57:41 +0530321 .of_match_table = tb10x_gpio_dt_ids,
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200322 .owner = THIS_MODULE,
323 }
324};
325
Wei Yongjun85aa3912013-10-30 11:08:55 +0800326module_platform_driver(tb10x_gpio_driver);
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200327MODULE_LICENSE("GPL");
328MODULE_DESCRIPTION("tb10x gpio.");
329MODULE_VERSION("0.0.1");