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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2019 SiFive
4 */
5
6#include <linux/bitops.h>
7#include <linux/device.h>
8#include <linux/errno.h>
9#include <linux/of_irq.h>
10#include <linux/gpio/driver.h>
11#include <linux/init.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <linux/regmap.h>
16
17#define SIFIVE_GPIO_INPUT_VAL 0x00
18#define SIFIVE_GPIO_INPUT_EN 0x04
19#define SIFIVE_GPIO_OUTPUT_EN 0x08
20#define SIFIVE_GPIO_OUTPUT_VAL 0x0C
21#define SIFIVE_GPIO_RISE_IE 0x18
22#define SIFIVE_GPIO_RISE_IP 0x1C
23#define SIFIVE_GPIO_FALL_IE 0x20
24#define SIFIVE_GPIO_FALL_IP 0x24
25#define SIFIVE_GPIO_HIGH_IE 0x28
26#define SIFIVE_GPIO_HIGH_IP 0x2C
27#define SIFIVE_GPIO_LOW_IE 0x30
28#define SIFIVE_GPIO_LOW_IP 0x34
29#define SIFIVE_GPIO_OUTPUT_XOR 0x40
30
31#define SIFIVE_GPIO_MAX 32
32
33struct sifive_gpio {
34 void __iomem *base;
35 struct gpio_chip gc;
36 struct regmap *regs;
37 unsigned long irq_state;
38 unsigned int trigger[SIFIVE_GPIO_MAX];
39 unsigned int irq_number[SIFIVE_GPIO_MAX];
40};
41
42static void sifive_gpio_set_ie(struct sifive_gpio *chip, unsigned int offset)
43{
44 unsigned long flags;
45 unsigned int trigger;
46
47 spin_lock_irqsave(&chip->gc.bgpio_lock, flags);
48 trigger = (chip->irq_state & BIT(offset)) ? chip->trigger[offset] : 0;
49 regmap_update_bits(chip->regs, SIFIVE_GPIO_RISE_IE, BIT(offset),
50 (trigger & IRQ_TYPE_EDGE_RISING) ? BIT(offset) : 0);
51 regmap_update_bits(chip->regs, SIFIVE_GPIO_FALL_IE, BIT(offset),
52 (trigger & IRQ_TYPE_EDGE_FALLING) ? BIT(offset) : 0);
53 regmap_update_bits(chip->regs, SIFIVE_GPIO_HIGH_IE, BIT(offset),
54 (trigger & IRQ_TYPE_LEVEL_HIGH) ? BIT(offset) : 0);
55 regmap_update_bits(chip->regs, SIFIVE_GPIO_LOW_IE, BIT(offset),
56 (trigger & IRQ_TYPE_LEVEL_LOW) ? BIT(offset) : 0);
57 spin_unlock_irqrestore(&chip->gc.bgpio_lock, flags);
58}
59
60static int sifive_gpio_irq_set_type(struct irq_data *d, unsigned int trigger)
61{
62 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
63 struct sifive_gpio *chip = gpiochip_get_data(gc);
64 int offset = irqd_to_hwirq(d);
65
66 if (offset < 0 || offset >= gc->ngpio)
67 return -EINVAL;
68
69 chip->trigger[offset] = trigger;
70 sifive_gpio_set_ie(chip, offset);
71 return 0;
72}
73
74static void sifive_gpio_irq_enable(struct irq_data *d)
75{
76 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
77 struct sifive_gpio *chip = gpiochip_get_data(gc);
78 int offset = irqd_to_hwirq(d) % SIFIVE_GPIO_MAX;
79 u32 bit = BIT(offset);
80 unsigned long flags;
81
82 irq_chip_enable_parent(d);
83
84 /* Switch to input */
85 gc->direction_input(gc, offset);
86
87 spin_lock_irqsave(&gc->bgpio_lock, flags);
88 /* Clear any sticky pending interrupts */
89 regmap_write(chip->regs, SIFIVE_GPIO_RISE_IP, bit);
90 regmap_write(chip->regs, SIFIVE_GPIO_FALL_IP, bit);
91 regmap_write(chip->regs, SIFIVE_GPIO_HIGH_IP, bit);
92 regmap_write(chip->regs, SIFIVE_GPIO_LOW_IP, bit);
93 spin_unlock_irqrestore(&gc->bgpio_lock, flags);
94
95 /* Enable interrupts */
96 assign_bit(offset, &chip->irq_state, 1);
97 sifive_gpio_set_ie(chip, offset);
98}
99
100static void sifive_gpio_irq_disable(struct irq_data *d)
101{
102 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
103 struct sifive_gpio *chip = gpiochip_get_data(gc);
104 int offset = irqd_to_hwirq(d) % SIFIVE_GPIO_MAX;
105
106 assign_bit(offset, &chip->irq_state, 0);
107 sifive_gpio_set_ie(chip, offset);
108 irq_chip_disable_parent(d);
109}
110
111static void sifive_gpio_irq_eoi(struct irq_data *d)
112{
113 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
114 struct sifive_gpio *chip = gpiochip_get_data(gc);
115 int offset = irqd_to_hwirq(d) % SIFIVE_GPIO_MAX;
116 u32 bit = BIT(offset);
117 unsigned long flags;
118
119 spin_lock_irqsave(&gc->bgpio_lock, flags);
120 /* Clear all pending interrupts */
121 regmap_write(chip->regs, SIFIVE_GPIO_RISE_IP, bit);
122 regmap_write(chip->regs, SIFIVE_GPIO_FALL_IP, bit);
123 regmap_write(chip->regs, SIFIVE_GPIO_HIGH_IP, bit);
124 regmap_write(chip->regs, SIFIVE_GPIO_LOW_IP, bit);
125 spin_unlock_irqrestore(&gc->bgpio_lock, flags);
126
127 irq_chip_eoi_parent(d);
128}
129
130static int sifive_gpio_irq_set_affinity(struct irq_data *data,
131 const struct cpumask *dest,
132 bool force)
133{
134 if (data->parent_data)
135 return irq_chip_set_affinity_parent(data, dest, force);
136
137 return -EINVAL;
138}
139
140static struct irq_chip sifive_gpio_irqchip = {
141 .name = "sifive-gpio",
142 .irq_set_type = sifive_gpio_irq_set_type,
143 .irq_mask = irq_chip_mask_parent,
144 .irq_unmask = irq_chip_unmask_parent,
145 .irq_enable = sifive_gpio_irq_enable,
146 .irq_disable = sifive_gpio_irq_disable,
147 .irq_eoi = sifive_gpio_irq_eoi,
148 .irq_set_affinity = sifive_gpio_irq_set_affinity,
149};
150
151static int sifive_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
152 unsigned int child,
153 unsigned int child_type,
154 unsigned int *parent,
155 unsigned int *parent_type)
156{
157 struct sifive_gpio *chip = gpiochip_get_data(gc);
158 struct irq_data *d = irq_get_irq_data(chip->irq_number[child]);
159
160 *parent_type = IRQ_TYPE_NONE;
161 *parent = irqd_to_hwirq(d);
162
163 return 0;
164}
165
166static const struct regmap_config sifive_gpio_regmap_config = {
167 .reg_bits = 32,
168 .reg_stride = 4,
169 .val_bits = 32,
170 .fast_io = true,
171 .disable_locking = true,
172};
173
174static int sifive_gpio_probe(struct platform_device *pdev)
175{
176 struct device *dev = &pdev->dev;
177 struct device_node *node = pdev->dev.of_node;
178 struct device_node *irq_parent;
179 struct irq_domain *parent;
180 struct gpio_irq_chip *girq;
181 struct sifive_gpio *chip;
182 int ret, ngpio, i;
183
184 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
185 if (!chip)
186 return -ENOMEM;
187
188 chip->base = devm_platform_ioremap_resource(pdev, 0);
189 if (IS_ERR(chip->base)) {
190 dev_err(dev, "failed to allocate device memory\n");
191 return PTR_ERR(chip->base);
192 }
193
194 chip->regs = devm_regmap_init_mmio(dev, chip->base,
195 &sifive_gpio_regmap_config);
196 if (IS_ERR(chip->regs))
197 return PTR_ERR(chip->regs);
198
199 ngpio = of_irq_count(node);
200 if (ngpio > SIFIVE_GPIO_MAX) {
201 dev_err(dev, "Too many GPIO interrupts (max=%d)\n",
202 SIFIVE_GPIO_MAX);
203 return -ENXIO;
204 }
205
206 irq_parent = of_irq_find_parent(node);
207 if (!irq_parent) {
208 dev_err(dev, "no IRQ parent node\n");
209 return -ENODEV;
210 }
211 parent = irq_find_host(irq_parent);
212 if (!parent) {
213 dev_err(dev, "no IRQ parent domain\n");
214 return -ENODEV;
215 }
216
217 for (i = 0; i < ngpio; i++)
218 chip->irq_number[i] = platform_get_irq(pdev, i);
219
220 ret = bgpio_init(&chip->gc, dev, 4,
221 chip->base + SIFIVE_GPIO_INPUT_VAL,
222 chip->base + SIFIVE_GPIO_OUTPUT_VAL,
223 NULL,
224 chip->base + SIFIVE_GPIO_OUTPUT_EN,
225 chip->base + SIFIVE_GPIO_INPUT_EN,
226 0);
227 if (ret) {
228 dev_err(dev, "unable to init generic GPIO\n");
229 return ret;
230 }
231
232 /* Disable all GPIO interrupts before enabling parent interrupts */
233 regmap_write(chip->regs, SIFIVE_GPIO_RISE_IE, 0);
234 regmap_write(chip->regs, SIFIVE_GPIO_FALL_IE, 0);
235 regmap_write(chip->regs, SIFIVE_GPIO_HIGH_IE, 0);
236 regmap_write(chip->regs, SIFIVE_GPIO_LOW_IE, 0);
237 chip->irq_state = 0;
238
239 chip->gc.base = -1;
240 chip->gc.ngpio = ngpio;
241 chip->gc.label = dev_name(dev);
242 chip->gc.parent = dev;
243 chip->gc.owner = THIS_MODULE;
244 girq = &chip->gc.irq;
245 girq->chip = &sifive_gpio_irqchip;
246 girq->fwnode = of_node_to_fwnode(node);
247 girq->parent_domain = parent;
248 girq->child_to_parent_hwirq = sifive_gpio_child_to_parent_hwirq;
249 girq->handler = handle_bad_irq;
250 girq->default_type = IRQ_TYPE_NONE;
251
252 platform_set_drvdata(pdev, chip);
253 return gpiochip_add_data(&chip->gc, chip);
254}
255
256static const struct of_device_id sifive_gpio_match[] = {
257 { .compatible = "sifive,gpio0" },
258 { .compatible = "sifive,fu540-c000-gpio" },
259 { },
260};
261
262static struct platform_driver sifive_gpio_driver = {
263 .probe = sifive_gpio_probe,
264 .driver = {
265 .name = "sifive_gpio",
266 .of_match_table = of_match_ptr(sifive_gpio_match),
267 },
268};
269builtin_platform_driver(sifive_gpio_driver)