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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
135 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
136
137 return 0;
138}
139
140static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset)
141{
142 return pinctrl_request_gpio(chip->base + offset);
143}
144
145static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset)
146{
147 pinctrl_free_gpio(chip->base + offset);
148}
149
150static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
151{
152 struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
153
154 return irq_create_mapping(tb10x_gpio->domain, offset);
155}
156
157static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
158{
159 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
160 pr_err("Only (both) edge triggered interrupts supported.\n");
161 return -EINVAL;
162 }
163
164 irqd_set_trigger_type(data, type);
165
166 return IRQ_SET_MASK_OK;
167}
168
169static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
170{
171 struct tb10x_gpio *tb10x_gpio = data;
172 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
173 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
174 const unsigned long bits = r & m;
175 int i;
176
177 for_each_set_bit(i, &bits, 32)
178 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
179
180 return IRQ_HANDLED;
181}
182
183static int tb10x_gpio_probe(struct platform_device *pdev)
184{
185 struct tb10x_gpio *tb10x_gpio;
186 struct resource *mem;
187 struct device_node *dn = pdev->dev.of_node;
188 int ret = -EBUSY;
189 u32 ngpio;
190
191 if (!dn)
192 return -EINVAL;
193
194 if (of_property_read_u32(dn, "abilis,ngpio", &ngpio))
195 return -EINVAL;
196
197 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
198 if (!mem) {
199 dev_err(&pdev->dev, "No memory resource defined.\n");
200 return -EINVAL;
201 }
202
203 tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
204 if (tb10x_gpio == NULL)
205 return -ENOMEM;
206
207 spin_lock_init(&tb10x_gpio->spinlock);
208
209 tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
Wei Yongjun9a4864c2013-10-30 11:09:15 +0800210 if (IS_ERR(tb10x_gpio->base))
211 return PTR_ERR(tb10x_gpio->base);
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200212
213 tb10x_gpio->gc.label = of_node_full_name(dn);
214 tb10x_gpio->gc.dev = &pdev->dev;
215 tb10x_gpio->gc.owner = THIS_MODULE;
216 tb10x_gpio->gc.direction_input = tb10x_gpio_direction_in;
217 tb10x_gpio->gc.get = tb10x_gpio_get;
218 tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out;
219 tb10x_gpio->gc.set = tb10x_gpio_set;
220 tb10x_gpio->gc.request = tb10x_gpio_request;
221 tb10x_gpio->gc.free = tb10x_gpio_free;
222 tb10x_gpio->gc.base = -1;
223 tb10x_gpio->gc.ngpio = ngpio;
224 tb10x_gpio->gc.can_sleep = 0;
225
226
227 ret = gpiochip_add(&tb10x_gpio->gc);
228 if (ret < 0) {
229 dev_err(&pdev->dev, "Could not add gpiochip.\n");
230 goto fail_gpiochip_registration;
231 }
232
233 platform_set_drvdata(pdev, tb10x_gpio);
234
235 if (of_find_property(dn, "interrupt-controller", NULL)) {
236 struct irq_chip_generic *gc;
237
238 ret = platform_get_irq(pdev, 0);
239 if (ret < 0) {
240 dev_err(&pdev->dev, "No interrupt specified.\n");
241 goto fail_get_irq;
242 }
243
244 tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq;
245 tb10x_gpio->irq = ret;
246
247 ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
248 IRQF_TRIGGER_NONE | IRQF_SHARED,
249 dev_name(&pdev->dev), tb10x_gpio);
250 if (ret != 0)
251 goto fail_request_irq;
252
253 tb10x_gpio->domain = irq_domain_add_linear(dn,
254 tb10x_gpio->gc.ngpio,
255 &irq_generic_chip_ops, NULL);
256 if (!tb10x_gpio->domain) {
257 ret = -ENOMEM;
258 goto fail_irq_domain;
259 }
260
261 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
262 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
263 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
264 IRQ_GC_INIT_MASK_CACHE);
265 if (ret)
266 goto fail_irq_domain;
267
268 gc = tb10x_gpio->domain->gc->gc[0];
269 gc->reg_base = tb10x_gpio->base;
270 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
271 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
272 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
273 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
274 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type;
275 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE;
276 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN;
277 }
278
279 return 0;
280
281fail_irq_domain:
282fail_request_irq:
283fail_get_irq:
284 gpiochip_remove(&tb10x_gpio->gc);
285fail_gpiochip_registration:
286fail_ioremap:
287 return ret;
288}
289
290static int __exit tb10x_gpio_remove(struct platform_device *pdev)
291{
292 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
293 int ret;
294
295 if (tb10x_gpio->gc.to_irq) {
296 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
297 BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
298 kfree(tb10x_gpio->domain->gc);
299 irq_domain_remove(tb10x_gpio->domain);
300 free_irq(tb10x_gpio->irq, tb10x_gpio);
301 }
302 ret = gpiochip_remove(&tb10x_gpio->gc);
303 if (ret)
304 return ret;
305
306 return 0;
307}
308
309static const struct of_device_id tb10x_gpio_dt_ids[] = {
310 { .compatible = "abilis,tb10x-gpio" },
311 { }
312};
313MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
314
315static struct platform_driver tb10x_gpio_driver = {
316 .probe = tb10x_gpio_probe,
317 .remove = tb10x_gpio_remove,
318 .driver = {
319 .name = "tb10x-gpio",
320 .of_match_table = of_match_ptr(tb10x_gpio_dt_ids),
321 .owner = THIS_MODULE,
322 }
323};
324
Wei Yongjun85aa3912013-10-30 11:08:55 +0800325module_platform_driver(tb10x_gpio_driver);
Christian Ruppertc6ce2b62013-10-08 14:25:22 +0200326MODULE_LICENSE("GPL");
327MODULE_DESCRIPTION("tb10x gpio.");
328MODULE_VERSION("0.0.1");