1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
4 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
5 */
6
7 #include <linux/err.h>
8 #include <linux/gpio/driver.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/of_irq.h>
13 #include <linux/platform_device.h>
14 #include <linux/spinlock.h>
15
16 #define MTK_BANK_CNT 3
17 #define MTK_BANK_WIDTH 32
18
19 #define GPIO_BANK_STRIDE 0x04
20 #define GPIO_REG_CTRL 0x00
21 #define GPIO_REG_POL 0x10
22 #define GPIO_REG_DATA 0x20
23 #define GPIO_REG_DSET 0x30
24 #define GPIO_REG_DCLR 0x40
25 #define GPIO_REG_REDGE 0x50
26 #define GPIO_REG_FEDGE 0x60
27 #define GPIO_REG_HLVL 0x70
28 #define GPIO_REG_LLVL 0x80
29 #define GPIO_REG_STAT 0x90
30 #define GPIO_REG_EDGE 0xA0
31
32 struct mtk_gc {
33 struct irq_chip irq_chip;
34 struct gpio_chip chip;
35 spinlock_t lock;
36 int bank;
37 u32 rising;
38 u32 falling;
39 u32 hlevel;
40 u32 llevel;
41 };
42
43 /**
44 * struct mtk - state container for
45 * data of the platform driver. It is 3
46 * separate gpio-chip each one with its
47 * own irq_chip.
48 * @dev: device instance
49 * @base: memory base address
50 * @gpio_irq: irq number from the device tree
51 * @gc_map: array of the gpio chips
52 */
53 struct mtk {
54 struct device *dev;
55 void __iomem *base;
56 int gpio_irq;
57 struct mtk_gc gc_map[MTK_BANK_CNT];
58 };
59
60 static inline struct mtk_gc *
to_mediatek_gpio(struct gpio_chip * chip)61 to_mediatek_gpio(struct gpio_chip *chip)
62 {
63 return container_of(chip, struct mtk_gc, chip);
64 }
65
66 static inline void
mtk_gpio_w32(struct mtk_gc * rg,u32 offset,u32 val)67 mtk_gpio_w32(struct mtk_gc *rg, u32 offset, u32 val)
68 {
69 struct gpio_chip *gc = &rg->chip;
70 struct mtk *mtk = gpiochip_get_data(gc);
71
72 offset = (rg->bank * GPIO_BANK_STRIDE) + offset;
73 gc->write_reg(mtk->base + offset, val);
74 }
75
76 static inline u32
mtk_gpio_r32(struct mtk_gc * rg,u32 offset)77 mtk_gpio_r32(struct mtk_gc *rg, u32 offset)
78 {
79 struct gpio_chip *gc = &rg->chip;
80 struct mtk *mtk = gpiochip_get_data(gc);
81
82 offset = (rg->bank * GPIO_BANK_STRIDE) + offset;
83 return gc->read_reg(mtk->base + offset);
84 }
85
86 static irqreturn_t
mediatek_gpio_irq_handler(int irq,void * data)87 mediatek_gpio_irq_handler(int irq, void *data)
88 {
89 struct gpio_chip *gc = data;
90 struct mtk_gc *rg = to_mediatek_gpio(gc);
91 irqreturn_t ret = IRQ_NONE;
92 unsigned long pending;
93 int bit;
94
95 pending = mtk_gpio_r32(rg, GPIO_REG_STAT);
96
97 for_each_set_bit(bit, &pending, MTK_BANK_WIDTH) {
98 u32 map = irq_find_mapping(gc->irq.domain, bit);
99
100 generic_handle_irq(map);
101 mtk_gpio_w32(rg, GPIO_REG_STAT, BIT(bit));
102 ret |= IRQ_HANDLED;
103 }
104
105 return ret;
106 }
107
108 static void
mediatek_gpio_irq_unmask(struct irq_data * d)109 mediatek_gpio_irq_unmask(struct irq_data *d)
110 {
111 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
112 struct mtk_gc *rg = to_mediatek_gpio(gc);
113 int pin = d->hwirq;
114 unsigned long flags;
115 u32 rise, fall, high, low;
116
117 spin_lock_irqsave(&rg->lock, flags);
118 rise = mtk_gpio_r32(rg, GPIO_REG_REDGE);
119 fall = mtk_gpio_r32(rg, GPIO_REG_FEDGE);
120 high = mtk_gpio_r32(rg, GPIO_REG_HLVL);
121 low = mtk_gpio_r32(rg, GPIO_REG_LLVL);
122 mtk_gpio_w32(rg, GPIO_REG_REDGE, rise | (BIT(pin) & rg->rising));
123 mtk_gpio_w32(rg, GPIO_REG_FEDGE, fall | (BIT(pin) & rg->falling));
124 mtk_gpio_w32(rg, GPIO_REG_HLVL, high | (BIT(pin) & rg->hlevel));
125 mtk_gpio_w32(rg, GPIO_REG_LLVL, low | (BIT(pin) & rg->llevel));
126 spin_unlock_irqrestore(&rg->lock, flags);
127 }
128
129 static void
mediatek_gpio_irq_mask(struct irq_data * d)130 mediatek_gpio_irq_mask(struct irq_data *d)
131 {
132 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
133 struct mtk_gc *rg = to_mediatek_gpio(gc);
134 int pin = d->hwirq;
135 unsigned long flags;
136 u32 rise, fall, high, low;
137
138 spin_lock_irqsave(&rg->lock, flags);
139 rise = mtk_gpio_r32(rg, GPIO_REG_REDGE);
140 fall = mtk_gpio_r32(rg, GPIO_REG_FEDGE);
141 high = mtk_gpio_r32(rg, GPIO_REG_HLVL);
142 low = mtk_gpio_r32(rg, GPIO_REG_LLVL);
143 mtk_gpio_w32(rg, GPIO_REG_FEDGE, fall & ~BIT(pin));
144 mtk_gpio_w32(rg, GPIO_REG_REDGE, rise & ~BIT(pin));
145 mtk_gpio_w32(rg, GPIO_REG_HLVL, high & ~BIT(pin));
146 mtk_gpio_w32(rg, GPIO_REG_LLVL, low & ~BIT(pin));
147 spin_unlock_irqrestore(&rg->lock, flags);
148 }
149
150 static int
mediatek_gpio_irq_type(struct irq_data * d,unsigned int type)151 mediatek_gpio_irq_type(struct irq_data *d, unsigned int type)
152 {
153 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
154 struct mtk_gc *rg = to_mediatek_gpio(gc);
155 int pin = d->hwirq;
156 u32 mask = BIT(pin);
157
158 if (type == IRQ_TYPE_PROBE) {
159 if ((rg->rising | rg->falling |
160 rg->hlevel | rg->llevel) & mask)
161 return 0;
162
163 type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
164 }
165
166 rg->rising &= ~mask;
167 rg->falling &= ~mask;
168 rg->hlevel &= ~mask;
169 rg->llevel &= ~mask;
170
171 switch (type & IRQ_TYPE_SENSE_MASK) {
172 case IRQ_TYPE_EDGE_BOTH:
173 rg->rising |= mask;
174 rg->falling |= mask;
175 break;
176 case IRQ_TYPE_EDGE_RISING:
177 rg->rising |= mask;
178 break;
179 case IRQ_TYPE_EDGE_FALLING:
180 rg->falling |= mask;
181 break;
182 case IRQ_TYPE_LEVEL_HIGH:
183 rg->hlevel |= mask;
184 break;
185 case IRQ_TYPE_LEVEL_LOW:
186 rg->llevel |= mask;
187 break;
188 }
189
190 return 0;
191 }
192
193 static int
mediatek_gpio_xlate(struct gpio_chip * chip,const struct of_phandle_args * spec,u32 * flags)194 mediatek_gpio_xlate(struct gpio_chip *chip,
195 const struct of_phandle_args *spec, u32 *flags)
196 {
197 int gpio = spec->args[0];
198 struct mtk_gc *rg = to_mediatek_gpio(chip);
199
200 if (rg->bank != gpio / MTK_BANK_WIDTH)
201 return -EINVAL;
202
203 if (flags)
204 *flags = spec->args[1];
205
206 return gpio % MTK_BANK_WIDTH;
207 }
208
209 static int
mediatek_gpio_bank_probe(struct device * dev,struct device_node * node,int bank)210 mediatek_gpio_bank_probe(struct device *dev,
211 struct device_node *node, int bank)
212 {
213 struct mtk *mtk = dev_get_drvdata(dev);
214 struct mtk_gc *rg;
215 void __iomem *dat, *set, *ctrl, *diro;
216 int ret;
217
218 rg = &mtk->gc_map[bank];
219 memset(rg, 0, sizeof(*rg));
220
221 spin_lock_init(&rg->lock);
222 rg->chip.of_node = node;
223 rg->bank = bank;
224
225 dat = mtk->base + GPIO_REG_DATA + (rg->bank * GPIO_BANK_STRIDE);
226 set = mtk->base + GPIO_REG_DSET + (rg->bank * GPIO_BANK_STRIDE);
227 ctrl = mtk->base + GPIO_REG_DCLR + (rg->bank * GPIO_BANK_STRIDE);
228 diro = mtk->base + GPIO_REG_CTRL + (rg->bank * GPIO_BANK_STRIDE);
229
230 ret = bgpio_init(&rg->chip, dev, 4, dat, set, ctrl, diro, NULL,
231 BGPIOF_NO_SET_ON_INPUT);
232 if (ret) {
233 dev_err(dev, "bgpio_init() failed\n");
234 return ret;
235 }
236
237 rg->chip.of_gpio_n_cells = 2;
238 rg->chip.of_xlate = mediatek_gpio_xlate;
239 rg->chip.label = devm_kasprintf(dev, GFP_KERNEL, "%s-bank%d",
240 dev_name(dev), bank);
241 if (!rg->chip.label)
242 return -ENOMEM;
243
244 rg->irq_chip.name = dev_name(dev);
245 rg->irq_chip.parent_device = dev;
246 rg->irq_chip.irq_unmask = mediatek_gpio_irq_unmask;
247 rg->irq_chip.irq_mask = mediatek_gpio_irq_mask;
248 rg->irq_chip.irq_mask_ack = mediatek_gpio_irq_mask;
249 rg->irq_chip.irq_set_type = mediatek_gpio_irq_type;
250
251 if (mtk->gpio_irq) {
252 struct gpio_irq_chip *girq;
253
254 /*
255 * Directly request the irq here instead of passing
256 * a flow-handler because the irq is shared.
257 */
258 ret = devm_request_irq(dev, mtk->gpio_irq,
259 mediatek_gpio_irq_handler, IRQF_SHARED,
260 rg->chip.label, &rg->chip);
261
262 if (ret) {
263 dev_err(dev, "Error requesting IRQ %d: %d\n",
264 mtk->gpio_irq, ret);
265 return ret;
266 }
267
268 girq = &rg->chip.irq;
269 girq->chip = &rg->irq_chip;
270 /* This will let us handle the parent IRQ in the driver */
271 girq->parent_handler = NULL;
272 girq->num_parents = 0;
273 girq->parents = NULL;
274 girq->default_type = IRQ_TYPE_NONE;
275 girq->handler = handle_simple_irq;
276 }
277
278 ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
279 if (ret < 0) {
280 dev_err(dev, "Could not register gpio %d, ret=%d\n",
281 rg->chip.ngpio, ret);
282 return ret;
283 }
284
285 /* set polarity to low for all gpios */
286 mtk_gpio_w32(rg, GPIO_REG_POL, 0);
287
288 dev_info(dev, "registering %d gpios\n", rg->chip.ngpio);
289
290 return 0;
291 }
292
293 static int
mediatek_gpio_probe(struct platform_device * pdev)294 mediatek_gpio_probe(struct platform_device *pdev)
295 {
296 struct device *dev = &pdev->dev;
297 struct device_node *np = dev->of_node;
298 struct mtk *mtk;
299 int i;
300 int ret;
301
302 mtk = devm_kzalloc(dev, sizeof(*mtk), GFP_KERNEL);
303 if (!mtk)
304 return -ENOMEM;
305
306 mtk->base = devm_platform_ioremap_resource(pdev, 0);
307 if (IS_ERR(mtk->base))
308 return PTR_ERR(mtk->base);
309
310 mtk->gpio_irq = irq_of_parse_and_map(np, 0);
311 mtk->dev = dev;
312 platform_set_drvdata(pdev, mtk);
313
314 for (i = 0; i < MTK_BANK_CNT; i++) {
315 ret = mediatek_gpio_bank_probe(dev, np, i);
316 if (ret)
317 return ret;
318 }
319
320 return 0;
321 }
322
323 static const struct of_device_id mediatek_gpio_match[] = {
324 { .compatible = "mediatek,mt7621-gpio" },
325 {},
326 };
327 MODULE_DEVICE_TABLE(of, mediatek_gpio_match);
328
329 static struct platform_driver mediatek_gpio_driver = {
330 .probe = mediatek_gpio_probe,
331 .driver = {
332 .name = "mt7621_gpio",
333 .of_match_table = mediatek_gpio_match,
334 },
335 };
336
337 builtin_platform_driver(mediatek_gpio_driver);
338
