1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * RDA Micro GPIO driver
4 *
5 * Copyright (C) 2012 RDA Micro Inc.
6 * Copyright (C) 2019 Manivannan Sadhasivam
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/spinlock.h>
15
16 #define RDA_GPIO_OEN_VAL 0x00
17 #define RDA_GPIO_OEN_SET_OUT 0x04
18 #define RDA_GPIO_OEN_SET_IN 0x08
19 #define RDA_GPIO_VAL 0x0c
20 #define RDA_GPIO_SET 0x10
21 #define RDA_GPIO_CLR 0x14
22 #define RDA_GPIO_INT_CTRL_SET 0x18
23 #define RDA_GPIO_INT_CTRL_CLR 0x1c
24 #define RDA_GPIO_INT_CLR 0x20
25 #define RDA_GPIO_INT_STATUS 0x24
26
27 #define RDA_GPIO_IRQ_RISE_SHIFT 0
28 #define RDA_GPIO_IRQ_FALL_SHIFT 8
29 #define RDA_GPIO_DEBOUCE_SHIFT 16
30 #define RDA_GPIO_LEVEL_SHIFT 24
31
32 #define RDA_GPIO_IRQ_MASK 0xff
33
34 /* Each bank consists of 32 GPIOs */
35 #define RDA_GPIO_BANK_NR 32
36
37 struct rda_gpio {
38 struct gpio_chip chip;
39 void __iomem *base;
40 spinlock_t lock;
41 int irq;
42 };
43
rda_gpio_update(struct gpio_chip * chip,unsigned int offset,u16 reg,int val)44 static inline void rda_gpio_update(struct gpio_chip *chip, unsigned int offset,
45 u16 reg, int val)
46 {
47 struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
48 void __iomem *base = rda_gpio->base;
49 unsigned long flags;
50 u32 tmp;
51
52 spin_lock_irqsave(&rda_gpio->lock, flags);
53 tmp = readl_relaxed(base + reg);
54
55 if (val)
56 tmp |= BIT(offset);
57 else
58 tmp &= ~BIT(offset);
59
60 writel_relaxed(tmp, base + reg);
61 spin_unlock_irqrestore(&rda_gpio->lock, flags);
62 }
63
rda_gpio_irq_mask(struct irq_data * data)64 static void rda_gpio_irq_mask(struct irq_data *data)
65 {
66 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
67 struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
68 void __iomem *base = rda_gpio->base;
69 u32 offset = irqd_to_hwirq(data);
70 u32 value;
71
72 value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
73 value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
74
75 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
76 gpiochip_disable_irq(chip, offset);
77 }
78
rda_gpio_irq_ack(struct irq_data * data)79 static void rda_gpio_irq_ack(struct irq_data *data)
80 {
81 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
82 u32 offset = irqd_to_hwirq(data);
83
84 rda_gpio_update(chip, offset, RDA_GPIO_INT_CLR, 1);
85 }
86
rda_gpio_set_irq(struct gpio_chip * chip,u32 offset,unsigned int flow_type)87 static int rda_gpio_set_irq(struct gpio_chip *chip, u32 offset,
88 unsigned int flow_type)
89 {
90 struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
91 void __iomem *base = rda_gpio->base;
92 u32 value;
93
94 switch (flow_type) {
95 case IRQ_TYPE_EDGE_RISING:
96 /* Set rising edge trigger */
97 value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
98 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
99
100 /* Switch to edge trigger interrupt */
101 value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
102 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
103 break;
104
105 case IRQ_TYPE_EDGE_FALLING:
106 /* Set falling edge trigger */
107 value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
108 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
109
110 /* Switch to edge trigger interrupt */
111 value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
112 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
113 break;
114
115 case IRQ_TYPE_EDGE_BOTH:
116 /* Set both edge trigger */
117 value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
118 value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
119 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
120
121 /* Switch to edge trigger interrupt */
122 value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
123 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
124 break;
125
126 case IRQ_TYPE_LEVEL_HIGH:
127 /* Set high level trigger */
128 value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
129
130 /* Switch to level trigger interrupt */
131 value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
132 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
133 break;
134
135 case IRQ_TYPE_LEVEL_LOW:
136 /* Set low level trigger */
137 value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
138
139 /* Switch to level trigger interrupt */
140 value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
141 writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
142 break;
143
144 default:
145 return -EINVAL;
146 }
147
148 return 0;
149 }
150
rda_gpio_irq_unmask(struct irq_data * data)151 static void rda_gpio_irq_unmask(struct irq_data *data)
152 {
153 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
154 u32 offset = irqd_to_hwirq(data);
155 u32 trigger = irqd_get_trigger_type(data);
156
157 gpiochip_enable_irq(chip, offset);
158 rda_gpio_set_irq(chip, offset, trigger);
159 }
160
rda_gpio_irq_set_type(struct irq_data * data,unsigned int flow_type)161 static int rda_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
162 {
163 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
164 u32 offset = irqd_to_hwirq(data);
165 int ret;
166
167 ret = rda_gpio_set_irq(chip, offset, flow_type);
168 if (ret)
169 return ret;
170
171 if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
172 irq_set_handler_locked(data, handle_level_irq);
173 else if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
174 irq_set_handler_locked(data, handle_edge_irq);
175
176 return 0;
177 }
178
rda_gpio_irq_handler(struct irq_desc * desc)179 static void rda_gpio_irq_handler(struct irq_desc *desc)
180 {
181 struct gpio_chip *chip = irq_desc_get_handler_data(desc);
182 struct irq_chip *ic = irq_desc_get_chip(desc);
183 struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
184 unsigned long status;
185 u32 n;
186
187 chained_irq_enter(ic, desc);
188
189 status = readl_relaxed(rda_gpio->base + RDA_GPIO_INT_STATUS);
190 /* Only lower 8 bits are capable of generating interrupts */
191 status &= RDA_GPIO_IRQ_MASK;
192
193 for_each_set_bit(n, &status, RDA_GPIO_BANK_NR)
194 generic_handle_domain_irq(chip->irq.domain, n);
195
196 chained_irq_exit(ic, desc);
197 }
198
199 static const struct irq_chip rda_gpio_irq_chip = {
200 .name = "rda-gpio",
201 .irq_ack = rda_gpio_irq_ack,
202 .irq_mask = rda_gpio_irq_mask,
203 .irq_unmask = rda_gpio_irq_unmask,
204 .irq_set_type = rda_gpio_irq_set_type,
205 .flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_IMMUTABLE,
206 GPIOCHIP_IRQ_RESOURCE_HELPERS,
207 };
208
rda_gpio_probe(struct platform_device * pdev)209 static int rda_gpio_probe(struct platform_device *pdev)
210 {
211 struct device *dev = &pdev->dev;
212 struct gpio_irq_chip *girq;
213 struct rda_gpio *rda_gpio;
214 u32 ngpios;
215 int ret;
216
217 rda_gpio = devm_kzalloc(dev, sizeof(*rda_gpio), GFP_KERNEL);
218 if (!rda_gpio)
219 return -ENOMEM;
220
221 ret = device_property_read_u32(dev, "ngpios", &ngpios);
222 if (ret < 0)
223 return ret;
224
225 /*
226 * Not all ports have interrupt capability. For instance, on
227 * RDA8810PL, GPIOC doesn't support interrupt. So we must handle
228 * those also.
229 */
230 rda_gpio->irq = platform_get_irq(pdev, 0);
231
232 rda_gpio->base = devm_platform_ioremap_resource(pdev, 0);
233 if (IS_ERR(rda_gpio->base))
234 return PTR_ERR(rda_gpio->base);
235
236 spin_lock_init(&rda_gpio->lock);
237
238 ret = bgpio_init(&rda_gpio->chip, dev, 4,
239 rda_gpio->base + RDA_GPIO_VAL,
240 rda_gpio->base + RDA_GPIO_SET,
241 rda_gpio->base + RDA_GPIO_CLR,
242 rda_gpio->base + RDA_GPIO_OEN_SET_OUT,
243 rda_gpio->base + RDA_GPIO_OEN_SET_IN,
244 BGPIOF_READ_OUTPUT_REG_SET);
245 if (ret) {
246 dev_err(dev, "bgpio_init failed\n");
247 return ret;
248 }
249
250 rda_gpio->chip.label = dev_name(dev);
251 rda_gpio->chip.ngpio = ngpios;
252 rda_gpio->chip.base = -1;
253
254 if (rda_gpio->irq >= 0) {
255 girq = &rda_gpio->chip.irq;
256 gpio_irq_chip_set_chip(girq, &rda_gpio_irq_chip);
257 girq->handler = handle_bad_irq;
258 girq->default_type = IRQ_TYPE_NONE;
259 girq->parent_handler = rda_gpio_irq_handler;
260 girq->parent_handler_data = rda_gpio;
261 girq->num_parents = 1;
262 girq->parents = devm_kcalloc(dev, 1,
263 sizeof(*girq->parents),
264 GFP_KERNEL);
265 if (!girq->parents)
266 return -ENOMEM;
267 girq->parents[0] = rda_gpio->irq;
268 }
269
270 platform_set_drvdata(pdev, rda_gpio);
271
272 return devm_gpiochip_add_data(dev, &rda_gpio->chip, rda_gpio);
273 }
274
275 static const struct of_device_id rda_gpio_of_match[] = {
276 { .compatible = "rda,8810pl-gpio", },
277 { /* sentinel */ }
278 };
279 MODULE_DEVICE_TABLE(of, rda_gpio_of_match);
280
281 static struct platform_driver rda_gpio_driver = {
282 .probe = rda_gpio_probe,
283 .driver = {
284 .name = "rda-gpio",
285 .of_match_table = rda_gpio_of_match,
286 },
287 };
288
289 module_platform_driver_probe(rda_gpio_driver, rda_gpio_probe);
290
291 MODULE_DESCRIPTION("RDA Micro GPIO driver");
292 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
293
