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
tb10x_reg_read(struct tb10x_gpio * gpio,unsigned int offs)63 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
64 {
65 return ioread32(gpio->base + offs);
66 }
67
tb10x_reg_write(struct tb10x_gpio * gpio,unsigned int offs,u32 val)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
tb10x_set_bits(struct tb10x_gpio * gpio,unsigned int offs,u32 mask,u32 val)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
tb10x_gpio_direction_in(struct gpio_chip * chip,unsigned offset)90 static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
91 {
92 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
93 int mask = BIT(offset);
94 int val = TB10X_GPIO_DIR_IN << offset;
95
96 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
97
98 return 0;
99 }
100
tb10x_gpio_get(struct gpio_chip * chip,unsigned offset)101 static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
102 {
103 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
104 int val;
105
106 val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);
107
108 if (val & BIT(offset))
109 return 1;
110 else
111 return 0;
112 }
113
tb10x_gpio_set(struct gpio_chip * chip,unsigned offset,int value)114 static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
115 {
116 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
117 int mask = BIT(offset);
118 int val = value << offset;
119
120 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
121 }
122
tb10x_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)123 static int tb10x_gpio_direction_out(struct gpio_chip *chip,
124 unsigned offset, int value)
125 {
126 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
127 int mask = BIT(offset);
128 int val = TB10X_GPIO_DIR_OUT << offset;
129
130 tb10x_gpio_set(chip, offset, value);
131 tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
132
133 return 0;
134 }
135
tb10x_gpio_to_irq(struct gpio_chip * chip,unsigned offset)136 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
137 {
138 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
139
140 return irq_create_mapping(tb10x_gpio->domain, offset);
141 }
142
tb10x_gpio_irq_set_type(struct irq_data * data,unsigned int type)143 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
144 {
145 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
146 pr_err("Only (both) edge triggered interrupts supported.\n");
147 return -EINVAL;
148 }
149
150 irqd_set_trigger_type(data, type);
151
152 return IRQ_SET_MASK_OK;
153 }
154
tb10x_gpio_irq_cascade(int irq,void * data)155 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
156 {
157 struct tb10x_gpio *tb10x_gpio = data;
158 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
159 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
160 const unsigned long bits = r & m;
161 int i;
162
163 for_each_set_bit(i, &bits, 32)
164 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
165
166 return IRQ_HANDLED;
167 }
168
tb10x_gpio_probe(struct platform_device * pdev)169 static int tb10x_gpio_probe(struct platform_device *pdev)
170 {
171 struct tb10x_gpio *tb10x_gpio;
172 struct resource *mem;
173 struct device_node *dn = pdev->dev.of_node;
174 int ret = -EBUSY;
175 u32 ngpio;
176
177 if (!dn)
178 return -EINVAL;
179
180 if (of_property_read_u32(dn, "abilis,ngpio", &ngpio))
181 return -EINVAL;
182
183 tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
184 if (tb10x_gpio == NULL)
185 return -ENOMEM;
186
187 spin_lock_init(&tb10x_gpio->spinlock);
188
189 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
190 tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
191 if (IS_ERR(tb10x_gpio->base))
192 return PTR_ERR(tb10x_gpio->base);
193
194 tb10x_gpio->gc.label = of_node_full_name(dn);
195 tb10x_gpio->gc.parent = &pdev->dev;
196 tb10x_gpio->gc.owner = THIS_MODULE;
197 tb10x_gpio->gc.direction_input = tb10x_gpio_direction_in;
198 tb10x_gpio->gc.get = tb10x_gpio_get;
199 tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out;
200 tb10x_gpio->gc.set = tb10x_gpio_set;
201 tb10x_gpio->gc.request = gpiochip_generic_request;
202 tb10x_gpio->gc.free = gpiochip_generic_free;
203 tb10x_gpio->gc.base = -1;
204 tb10x_gpio->gc.ngpio = ngpio;
205 tb10x_gpio->gc.can_sleep = false;
206
207
208 ret = devm_gpiochip_add_data(&pdev->dev, &tb10x_gpio->gc, tb10x_gpio);
209 if (ret < 0) {
210 dev_err(&pdev->dev, "Could not add gpiochip.\n");
211 return ret;
212 }
213
214 platform_set_drvdata(pdev, tb10x_gpio);
215
216 if (of_find_property(dn, "interrupt-controller", NULL)) {
217 struct irq_chip_generic *gc;
218
219 ret = platform_get_irq(pdev, 0);
220 if (ret < 0) {
221 dev_err(&pdev->dev, "No interrupt specified.\n");
222 return ret;
223 }
224
225 tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq;
226 tb10x_gpio->irq = ret;
227
228 ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
229 IRQF_TRIGGER_NONE | IRQF_SHARED,
230 dev_name(&pdev->dev), tb10x_gpio);
231 if (ret != 0)
232 return ret;
233
234 tb10x_gpio->domain = irq_domain_add_linear(dn,
235 tb10x_gpio->gc.ngpio,
236 &irq_generic_chip_ops, NULL);
237 if (!tb10x_gpio->domain) {
238 return -ENOMEM;
239 }
240
241 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
242 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
243 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
244 IRQ_GC_INIT_MASK_CACHE);
245 if (ret)
246 return ret;
247
248 gc = tb10x_gpio->domain->gc->gc[0];
249 gc->reg_base = tb10x_gpio->base;
250 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
251 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
252 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
253 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
254 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type;
255 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE;
256 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN;
257 }
258
259 return 0;
260 }
261
tb10x_gpio_remove(struct platform_device * pdev)262 static int tb10x_gpio_remove(struct platform_device *pdev)
263 {
264 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
265
266 if (tb10x_gpio->gc.to_irq) {
267 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
268 BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
269 kfree(tb10x_gpio->domain->gc);
270 irq_domain_remove(tb10x_gpio->domain);
271 }
272
273 return 0;
274 }
275
276 static const struct of_device_id tb10x_gpio_dt_ids[] = {
277 { .compatible = "abilis,tb10x-gpio" },
278 { }
279 };
280 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
281
282 static struct platform_driver tb10x_gpio_driver = {
283 .probe = tb10x_gpio_probe,
284 .remove = tb10x_gpio_remove,
285 .driver = {
286 .name = "tb10x-gpio",
287 .of_match_table = tb10x_gpio_dt_ids,
288 }
289 };
290
291 module_platform_driver(tb10x_gpio_driver);
292 MODULE_LICENSE("GPL");
293 MODULE_DESCRIPTION("tb10x gpio.");
294 MODULE_VERSION("0.0.1");
295