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
32struct 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 */
53struct mtk {
54 struct device *dev;
55 void __iomem *base;
56 int gpio_irq;
57 struct mtk_gc gc_map[MTK_BANK_CNT];
58};
59
60static inline struct mtk_gc *
61to_mediatek_gpio(struct gpio_chip *chip)
62{
63 return container_of(chip, struct mtk_gc, chip);
64}
65
66static inline void
67mtk_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
76static inline u32
77mtk_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
86static irqreturn_t
87mediatek_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
108static void
109mediatek_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
129static void
130mediatek_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
150static int
151mediatek_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
193static int
194mediatek_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
209static int
210mediatek_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,
231 dat, set, ctrl, diro, NULL, 0);
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 ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
245 if (ret < 0) {
246 dev_err(dev, "Could not register gpio %d, ret=%d\n",
247 rg->chip.ngpio, ret);
248 return ret;
249 }
250
251 rg->irq_chip.name = dev_name(dev);
252 rg->irq_chip.parent_device = dev;
253 rg->irq_chip.irq_unmask = mediatek_gpio_irq_unmask;
254 rg->irq_chip.irq_mask = mediatek_gpio_irq_mask;
255 rg->irq_chip.irq_mask_ack = mediatek_gpio_irq_mask;
256 rg->irq_chip.irq_set_type = mediatek_gpio_irq_type;
257
258 if (mtk->gpio_irq) {
259 /*
260 * Manually request the irq here instead of passing
261 * a flow-handler to gpiochip_set_chained_irqchip,
262 * because the irq is shared.
263 */
264 ret = devm_request_irq(dev, mtk->gpio_irq,
265 mediatek_gpio_irq_handler, IRQF_SHARED,
266 rg->chip.label, &rg->chip);
267
268 if (ret) {
269 dev_err(dev, "Error requesting IRQ %d: %d\n",
270 mtk->gpio_irq, ret);
271 return ret;
272 }
273
274 ret = gpiochip_irqchip_add(&rg->chip, &rg->irq_chip,
275 0, handle_simple_irq, IRQ_TYPE_NONE);
276 if (ret) {
277 dev_err(dev, "failed to add gpiochip_irqchip\n");
278 return ret;
279 }
280
281 gpiochip_set_chained_irqchip(&rg->chip, &rg->irq_chip,
282 mtk->gpio_irq, NULL);
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
293static int
294mediatek_gpio_probe(struct platform_device *pdev)
295{
296 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297 struct device *dev = &pdev->dev;
298 struct device_node *np = dev->of_node;
299 struct mtk *mtk;
300 int i;
301 int ret;
302
303 mtk = devm_kzalloc(dev, sizeof(*mtk), GFP_KERNEL);
304 if (!mtk)
305 return -ENOMEM;
306
307 mtk->base = devm_ioremap_resource(dev, res);
308 if (IS_ERR(mtk->base))
309 return PTR_ERR(mtk->base);
310
311 mtk->gpio_irq = irq_of_parse_and_map(np, 0);
312 mtk->dev = dev;
313 platform_set_drvdata(pdev, mtk);
314
315 for (i = 0; i < MTK_BANK_CNT; i++) {
316 ret = mediatek_gpio_bank_probe(dev, np, i);
317 if (ret)
318 return ret;
319 }
320
321 return 0;
322}
323
324static const struct of_device_id mediatek_gpio_match[] = {
325 { .compatible = "mediatek,mt7621-gpio" },
326 {},
327};
328MODULE_DEVICE_TABLE(of, mediatek_gpio_match);
329
330static struct platform_driver mediatek_gpio_driver = {
331 .probe = mediatek_gpio_probe,
332 .driver = {
333 .name = "mt7621_gpio",
334 .of_match_table = mediatek_gpio_match,
335 },
336};
337
338builtin_platform_driver(mediatek_gpio_driver);
339