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1 | /* 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 | */ | |
55 | struct 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 | ||
63 | static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs) | |
64 | { | |
65 | return ioread32(gpio->base + offs); | |
66 | } | |
67 | ||
68 | static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs, | |
69 | u32 val) | |
70 | { | |
71 | iowrite32(val, gpio->base + offs); | |
72 | } | |
73 | ||
74 | static 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 | ||
90 | static inline struct tb10x_gpio *to_tb10x_gpio(struct gpio_chip *chip) | |
91 | { | |
92 | return container_of(chip, struct tb10x_gpio, gc); | |
93 | } | |
94 | ||
95 | static 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 | ||
106 | static 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 | ||
119 | static 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 | ||
128 | static 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 | ||
140 | static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset) | |
141 | { | |
142 | return pinctrl_request_gpio(chip->base + offset); | |
143 | } | |
144 | ||
145 | static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset) | |
146 | { | |
147 | pinctrl_free_gpio(chip->base + offset); | |
148 | } | |
149 | ||
150 | static 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 | ||
157 | static 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 | ||
169 | static 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 | ||
183 | static 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); | |
210 | if (!tb10x_gpio->base) { | |
211 | dev_err(&pdev->dev, "Could not remap reg space.\n"); | |
212 | goto fail_ioremap; | |
213 | } | |
214 | ||
215 | tb10x_gpio->gc.label = of_node_full_name(dn); | |
216 | tb10x_gpio->gc.dev = &pdev->dev; | |
217 | tb10x_gpio->gc.owner = THIS_MODULE; | |
218 | tb10x_gpio->gc.direction_input = tb10x_gpio_direction_in; | |
219 | tb10x_gpio->gc.get = tb10x_gpio_get; | |
220 | tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out; | |
221 | tb10x_gpio->gc.set = tb10x_gpio_set; | |
222 | tb10x_gpio->gc.request = tb10x_gpio_request; | |
223 | tb10x_gpio->gc.free = tb10x_gpio_free; | |
224 | tb10x_gpio->gc.base = -1; | |
225 | tb10x_gpio->gc.ngpio = ngpio; | |
226 | tb10x_gpio->gc.can_sleep = 0; | |
227 | ||
228 | ||
229 | ret = gpiochip_add(&tb10x_gpio->gc); | |
230 | if (ret < 0) { | |
231 | dev_err(&pdev->dev, "Could not add gpiochip.\n"); | |
232 | goto fail_gpiochip_registration; | |
233 | } | |
234 | ||
235 | platform_set_drvdata(pdev, tb10x_gpio); | |
236 | ||
237 | if (of_find_property(dn, "interrupt-controller", NULL)) { | |
238 | struct irq_chip_generic *gc; | |
239 | ||
240 | ret = platform_get_irq(pdev, 0); | |
241 | if (ret < 0) { | |
242 | dev_err(&pdev->dev, "No interrupt specified.\n"); | |
243 | goto fail_get_irq; | |
244 | } | |
245 | ||
246 | tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq; | |
247 | tb10x_gpio->irq = ret; | |
248 | ||
249 | ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade, | |
250 | IRQF_TRIGGER_NONE | IRQF_SHARED, | |
251 | dev_name(&pdev->dev), tb10x_gpio); | |
252 | if (ret != 0) | |
253 | goto fail_request_irq; | |
254 | ||
255 | tb10x_gpio->domain = irq_domain_add_linear(dn, | |
256 | tb10x_gpio->gc.ngpio, | |
257 | &irq_generic_chip_ops, NULL); | |
258 | if (!tb10x_gpio->domain) { | |
259 | ret = -ENOMEM; | |
260 | goto fail_irq_domain; | |
261 | } | |
262 | ||
263 | ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain, | |
264 | tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label, | |
265 | handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE, | |
266 | IRQ_GC_INIT_MASK_CACHE); | |
267 | if (ret) | |
268 | goto fail_irq_domain; | |
269 | ||
270 | gc = tb10x_gpio->domain->gc->gc[0]; | |
271 | gc->reg_base = tb10x_gpio->base; | |
272 | gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH; | |
273 | gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit; | |
274 | gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit; | |
275 | gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit; | |
276 | gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type; | |
277 | gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE; | |
278 | gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN; | |
279 | } | |
280 | ||
281 | return 0; | |
282 | ||
283 | fail_irq_domain: | |
284 | fail_request_irq: | |
285 | fail_get_irq: | |
286 | gpiochip_remove(&tb10x_gpio->gc); | |
287 | fail_gpiochip_registration: | |
288 | fail_ioremap: | |
289 | return ret; | |
290 | } | |
291 | ||
292 | static int __exit tb10x_gpio_remove(struct platform_device *pdev) | |
293 | { | |
294 | struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev); | |
295 | int ret; | |
296 | ||
297 | if (tb10x_gpio->gc.to_irq) { | |
298 | irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0], | |
299 | BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0); | |
300 | kfree(tb10x_gpio->domain->gc); | |
301 | irq_domain_remove(tb10x_gpio->domain); | |
302 | free_irq(tb10x_gpio->irq, tb10x_gpio); | |
303 | } | |
304 | ret = gpiochip_remove(&tb10x_gpio->gc); | |
305 | if (ret) | |
306 | return ret; | |
307 | ||
308 | return 0; | |
309 | } | |
310 | ||
311 | static const struct of_device_id tb10x_gpio_dt_ids[] = { | |
312 | { .compatible = "abilis,tb10x-gpio" }, | |
313 | { } | |
314 | }; | |
315 | MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids); | |
316 | ||
317 | static struct platform_driver tb10x_gpio_driver = { | |
318 | .probe = tb10x_gpio_probe, | |
319 | .remove = tb10x_gpio_remove, | |
320 | .driver = { | |
321 | .name = "tb10x-gpio", | |
322 | .of_match_table = of_match_ptr(tb10x_gpio_dt_ids), | |
323 | .owner = THIS_MODULE, | |
324 | } | |
325 | }; | |
326 | ||
327 | static int __init ab_gpio_init(void) | |
328 | { | |
329 | return platform_driver_register(&tb10x_gpio_driver); | |
330 | } | |
331 | ||
332 | static void __exit ab_gpio_exit(void) | |
333 | { | |
334 | platform_driver_unregister(&tb10x_gpio_driver); | |
335 | } | |
336 | ||
337 | module_init(ab_gpio_init); | |
338 | module_exit(ab_gpio_exit); | |
339 | MODULE_LICENSE("GPL"); | |
340 | MODULE_DESCRIPTION("tb10x gpio."); | |
341 | MODULE_VERSION("0.0.1"); |