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/platform_device.h>
13 #include <linux/spinlock.h>
14
15 #define MTK_BANK_CNT 3
16 #define MTK_BANK_WIDTH 32
17
18 #define GPIO_BANK_STRIDE 0x04
19 #define GPIO_REG_CTRL 0x00
20 #define GPIO_REG_POL 0x10
21 #define GPIO_REG_DATA 0x20
22 #define GPIO_REG_DSET 0x30
23 #define GPIO_REG_DCLR 0x40
24 #define GPIO_REG_REDGE 0x50
25 #define GPIO_REG_FEDGE 0x60
26 #define GPIO_REG_HLVL 0x70
27 #define GPIO_REG_LLVL 0x80
28 #define GPIO_REG_STAT 0x90
29 #define GPIO_REG_EDGE 0xA0
30
31 struct mtk_gc {
32 struct irq_chip irq_chip;
33 struct gpio_chip chip;
34 spinlock_t lock;
35 int bank;
36 u32 rising;
37 u32 falling;
38 u32 hlevel;
39 u32 llevel;
40 };
41
42 /**
43 * struct mtk - state container for
44 * data of the platform driver. It is 3
45 * separate gpio-chip each one with its
46 * own irq_chip.
47 * @dev: device instance
48 * @base: memory base address
49 * @gpio_irq: irq number from the device tree
50 * @gc_map: array of the gpio chips
51 */
52 struct mtk {
53 struct device *dev;
54 void __iomem *base;
55 int gpio_irq;
56 struct mtk_gc gc_map[MTK_BANK_CNT];
57 };
58
59 static inline struct mtk_gc *
to_mediatek_gpio(struct gpio_chip * chip)60 to_mediatek_gpio(struct gpio_chip *chip)
61 {
62 return container_of(chip, struct mtk_gc, chip);
63 }
64
65 static inline void
mtk_gpio_w32(struct mtk_gc * rg,u32 offset,u32 val)66 mtk_gpio_w32(struct mtk_gc *rg, u32 offset, u32 val)
67 {
68 struct gpio_chip *gc = &rg->chip;
69 struct mtk *mtk = gpiochip_get_data(gc);
70
71 offset = (rg->bank * GPIO_BANK_STRIDE) + offset;
72 gc->write_reg(mtk->base + offset, val);
73 }
74
75 static inline u32
mtk_gpio_r32(struct mtk_gc * rg,u32 offset)76 mtk_gpio_r32(struct mtk_gc *rg, u32 offset)
77 {
78 struct gpio_chip *gc = &rg->chip;
79 struct mtk *mtk = gpiochip_get_data(gc);
80
81 offset = (rg->bank * GPIO_BANK_STRIDE) + offset;
82 return gc->read_reg(mtk->base + offset);
83 }
84
85 static irqreturn_t
mediatek_gpio_irq_handler(int irq,void * data)86 mediatek_gpio_irq_handler(int irq, void *data)
87 {
88 struct gpio_chip *gc = data;
89 struct mtk_gc *rg = to_mediatek_gpio(gc);
90 irqreturn_t ret = IRQ_NONE;
91 unsigned long pending;
92 int bit;
93
94 pending = mtk_gpio_r32(rg, GPIO_REG_STAT);
95
96 for_each_set_bit(bit, &pending, MTK_BANK_WIDTH) {
97 generic_handle_domain_irq(gc->irq.domain, bit);
98 mtk_gpio_w32(rg, GPIO_REG_STAT, BIT(bit));
99 ret |= IRQ_HANDLED;
100 }
101
102 return ret;
103 }
104
105 static void
mediatek_gpio_irq_unmask(struct irq_data * d)106 mediatek_gpio_irq_unmask(struct irq_data *d)
107 {
108 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
109 struct mtk_gc *rg = to_mediatek_gpio(gc);
110 int pin = d->hwirq;
111 unsigned long flags;
112 u32 rise, fall, high, low;
113
114 gpiochip_enable_irq(gc, d->hwirq);
115
116 spin_lock_irqsave(&rg->lock, flags);
117 rise = mtk_gpio_r32(rg, GPIO_REG_REDGE);
118 fall = mtk_gpio_r32(rg, GPIO_REG_FEDGE);
119 high = mtk_gpio_r32(rg, GPIO_REG_HLVL);
120 low = mtk_gpio_r32(rg, GPIO_REG_LLVL);
121 mtk_gpio_w32(rg, GPIO_REG_REDGE, rise | (BIT(pin) & rg->rising));
122 mtk_gpio_w32(rg, GPIO_REG_FEDGE, fall | (BIT(pin) & rg->falling));
123 mtk_gpio_w32(rg, GPIO_REG_HLVL, high | (BIT(pin) & rg->hlevel));
124 mtk_gpio_w32(rg, GPIO_REG_LLVL, low | (BIT(pin) & rg->llevel));
125 spin_unlock_irqrestore(&rg->lock, flags);
126 }
127
128 static void
mediatek_gpio_irq_mask(struct irq_data * d)129 mediatek_gpio_irq_mask(struct irq_data *d)
130 {
131 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
132 struct mtk_gc *rg = to_mediatek_gpio(gc);
133 int pin = d->hwirq;
134 unsigned long flags;
135 u32 rise, fall, high, low;
136
137 spin_lock_irqsave(&rg->lock, flags);
138 rise = mtk_gpio_r32(rg, GPIO_REG_REDGE);
139 fall = mtk_gpio_r32(rg, GPIO_REG_FEDGE);
140 high = mtk_gpio_r32(rg, GPIO_REG_HLVL);
141 low = mtk_gpio_r32(rg, GPIO_REG_LLVL);
142 mtk_gpio_w32(rg, GPIO_REG_FEDGE, fall & ~BIT(pin));
143 mtk_gpio_w32(rg, GPIO_REG_REDGE, rise & ~BIT(pin));
144 mtk_gpio_w32(rg, GPIO_REG_HLVL, high & ~BIT(pin));
145 mtk_gpio_w32(rg, GPIO_REG_LLVL, low & ~BIT(pin));
146 spin_unlock_irqrestore(&rg->lock, flags);
147
148 gpiochip_disable_irq(gc, d->hwirq);
149 }
150
151 static int
mediatek_gpio_irq_type(struct irq_data * d,unsigned int type)152 mediatek_gpio_irq_type(struct irq_data *d, unsigned int type)
153 {
154 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
155 struct mtk_gc *rg = to_mediatek_gpio(gc);
156 int pin = d->hwirq;
157 u32 mask = BIT(pin);
158
159 if (type == IRQ_TYPE_PROBE) {
160 if ((rg->rising | rg->falling |
161 rg->hlevel | rg->llevel) & mask)
162 return 0;
163
164 type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
165 }
166
167 rg->rising &= ~mask;
168 rg->falling &= ~mask;
169 rg->hlevel &= ~mask;
170 rg->llevel &= ~mask;
171
172 switch (type & IRQ_TYPE_SENSE_MASK) {
173 case IRQ_TYPE_EDGE_BOTH:
174 rg->rising |= mask;
175 rg->falling |= mask;
176 break;
177 case IRQ_TYPE_EDGE_RISING:
178 rg->rising |= mask;
179 break;
180 case IRQ_TYPE_EDGE_FALLING:
181 rg->falling |= mask;
182 break;
183 case IRQ_TYPE_LEVEL_HIGH:
184 rg->hlevel |= mask;
185 break;
186 case IRQ_TYPE_LEVEL_LOW:
187 rg->llevel |= mask;
188 break;
189 }
190
191 return 0;
192 }
193
194 static int
mediatek_gpio_xlate(struct gpio_chip * chip,const struct of_phandle_args * spec,u32 * flags)195 mediatek_gpio_xlate(struct gpio_chip *chip,
196 const struct of_phandle_args *spec, u32 *flags)
197 {
198 int gpio = spec->args[0];
199 struct mtk_gc *rg = to_mediatek_gpio(chip);
200
201 if (rg->bank != gpio / MTK_BANK_WIDTH)
202 return -EINVAL;
203
204 if (flags)
205 *flags = spec->args[1];
206
207 return gpio % MTK_BANK_WIDTH;
208 }
209
210 static const struct irq_chip mt7621_irq_chip = {
211 .name = "mt7621-gpio",
212 .irq_mask_ack = mediatek_gpio_irq_mask,
213 .irq_mask = mediatek_gpio_irq_mask,
214 .irq_unmask = mediatek_gpio_irq_unmask,
215 .irq_set_type = mediatek_gpio_irq_type,
216 .flags = IRQCHIP_IMMUTABLE,
217 GPIOCHIP_IRQ_RESOURCE_HELPERS,
218 };
219
220 static int
mediatek_gpio_bank_probe(struct device * dev,int bank)221 mediatek_gpio_bank_probe(struct device *dev, int bank)
222 {
223 struct mtk *mtk = dev_get_drvdata(dev);
224 struct mtk_gc *rg;
225 void __iomem *dat, *set, *ctrl, *diro;
226 int ret;
227
228 rg = &mtk->gc_map[bank];
229 memset(rg, 0, sizeof(*rg));
230
231 spin_lock_init(&rg->lock);
232 rg->bank = bank;
233
234 dat = mtk->base + GPIO_REG_DATA + (rg->bank * GPIO_BANK_STRIDE);
235 set = mtk->base + GPIO_REG_DSET + (rg->bank * GPIO_BANK_STRIDE);
236 ctrl = mtk->base + GPIO_REG_DCLR + (rg->bank * GPIO_BANK_STRIDE);
237 diro = mtk->base + GPIO_REG_CTRL + (rg->bank * GPIO_BANK_STRIDE);
238
239 ret = bgpio_init(&rg->chip, dev, 4, dat, set, ctrl, diro, NULL,
240 BGPIOF_NO_SET_ON_INPUT);
241 if (ret) {
242 dev_err(dev, "bgpio_init() failed\n");
243 return ret;
244 }
245
246 rg->chip.of_gpio_n_cells = 2;
247 rg->chip.of_xlate = mediatek_gpio_xlate;
248 rg->chip.label = devm_kasprintf(dev, GFP_KERNEL, "%s-bank%d",
249 dev_name(dev), bank);
250 if (!rg->chip.label)
251 return -ENOMEM;
252
253 rg->chip.offset = bank * MTK_BANK_WIDTH;
254
255 if (mtk->gpio_irq) {
256 struct gpio_irq_chip *girq;
257
258 /*
259 * Directly request the irq here instead of passing
260 * a flow-handler because the irq is shared.
261 */
262 ret = devm_request_irq(dev, mtk->gpio_irq,
263 mediatek_gpio_irq_handler, IRQF_SHARED,
264 rg->chip.label, &rg->chip);
265
266 if (ret) {
267 dev_err(dev, "Error requesting IRQ %d: %d\n",
268 mtk->gpio_irq, ret);
269 return ret;
270 }
271
272 girq = &rg->chip.irq;
273 gpio_irq_chip_set_chip(girq, &mt7621_irq_chip);
274 /* This will let us handle the parent IRQ in the driver */
275 girq->parent_handler = NULL;
276 girq->num_parents = 0;
277 girq->parents = NULL;
278 girq->default_type = IRQ_TYPE_NONE;
279 girq->handler = handle_simple_irq;
280 }
281
282 ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
283 if (ret < 0) {
284 dev_err(dev, "Could not register gpio %d, ret=%d\n",
285 rg->chip.ngpio, ret);
286 return ret;
287 }
288
289 /* set polarity to low for all gpios */
290 mtk_gpio_w32(rg, GPIO_REG_POL, 0);
291
292 dev_info(dev, "registering %d gpios\n", rg->chip.ngpio);
293
294 return 0;
295 }
296
297 static int
mediatek_gpio_probe(struct platform_device * pdev)298 mediatek_gpio_probe(struct platform_device *pdev)
299 {
300 struct device *dev = &pdev->dev;
301 struct mtk *mtk;
302 int i;
303 int ret;
304
305 mtk = devm_kzalloc(dev, sizeof(*mtk), GFP_KERNEL);
306 if (!mtk)
307 return -ENOMEM;
308
309 mtk->base = devm_platform_ioremap_resource(pdev, 0);
310 if (IS_ERR(mtk->base))
311 return PTR_ERR(mtk->base);
312
313 mtk->gpio_irq = platform_get_irq(pdev, 0);
314 if (mtk->gpio_irq < 0)
315 return mtk->gpio_irq;
316
317 mtk->dev = dev;
318 platform_set_drvdata(pdev, mtk);
319
320 for (i = 0; i < MTK_BANK_CNT; i++) {
321 ret = mediatek_gpio_bank_probe(dev, i);
322 if (ret)
323 return ret;
324 }
325
326 return 0;
327 }
328
329 static const struct of_device_id mediatek_gpio_match[] = {
330 { .compatible = "mediatek,mt7621-gpio" },
331 {},
332 };
333 MODULE_DEVICE_TABLE(of, mediatek_gpio_match);
334
335 static struct platform_driver mediatek_gpio_driver = {
336 .probe = mediatek_gpio_probe,
337 .driver = {
338 .name = "mt7621_gpio",
339 .of_match_table = mediatek_gpio_match,
340 },
341 };
342
343 builtin_platform_driver(mediatek_gpio_driver);
344