1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Faraday Technolog FTGPIO010 gpiochip and interrupt routines
4 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
5 *
6 * Based on arch/arm/mach-gemini/gpio.c:
7 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
8 *
9 * Based on plat-mxc/gpio.c:
10 * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
11 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
12 */
13 #include <linux/gpio/driver.h>
14 #include <linux/io.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/bitops.h>
18
19 /* GPIO registers definition */
20 #define GPIO_DATA_OUT 0x00
21 #define GPIO_DATA_IN 0x04
22 #define GPIO_DIR 0x08
23 #define GPIO_BYPASS_IN 0x0C
24 #define GPIO_DATA_SET 0x10
25 #define GPIO_DATA_CLR 0x14
26 #define GPIO_PULL_EN 0x18
27 #define GPIO_PULL_TYPE 0x1C
28 #define GPIO_INT_EN 0x20
29 #define GPIO_INT_STAT_RAW 0x24
30 #define GPIO_INT_STAT_MASKED 0x28
31 #define GPIO_INT_MASK 0x2C
32 #define GPIO_INT_CLR 0x30
33 #define GPIO_INT_TYPE 0x34
34 #define GPIO_INT_BOTH_EDGE 0x38
35 #define GPIO_INT_LEVEL 0x3C
36 #define GPIO_DEBOUNCE_EN 0x40
37 #define GPIO_DEBOUNCE_PRESCALE 0x44
38
39 /**
40 * struct ftgpio_gpio - Gemini GPIO state container
41 * @dev: containing device for this instance
42 * @gc: gpiochip for this instance
43 */
44 struct ftgpio_gpio {
45 struct device *dev;
46 struct gpio_chip gc;
47 void __iomem *base;
48 };
49
ftgpio_gpio_ack_irq(struct irq_data * d)50 static void ftgpio_gpio_ack_irq(struct irq_data *d)
51 {
52 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
53 struct ftgpio_gpio *g = gpiochip_get_data(gc);
54
55 writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR);
56 }
57
ftgpio_gpio_mask_irq(struct irq_data * d)58 static void ftgpio_gpio_mask_irq(struct irq_data *d)
59 {
60 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
61 struct ftgpio_gpio *g = gpiochip_get_data(gc);
62 u32 val;
63
64 val = readl(g->base + GPIO_INT_EN);
65 val &= ~BIT(irqd_to_hwirq(d));
66 writel(val, g->base + GPIO_INT_EN);
67 }
68
ftgpio_gpio_unmask_irq(struct irq_data * d)69 static void ftgpio_gpio_unmask_irq(struct irq_data *d)
70 {
71 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
72 struct ftgpio_gpio *g = gpiochip_get_data(gc);
73 u32 val;
74
75 val = readl(g->base + GPIO_INT_EN);
76 val |= BIT(irqd_to_hwirq(d));
77 writel(val, g->base + GPIO_INT_EN);
78 }
79
ftgpio_gpio_set_irq_type(struct irq_data * d,unsigned int type)80 static int ftgpio_gpio_set_irq_type(struct irq_data *d, unsigned int type)
81 {
82 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
83 struct ftgpio_gpio *g = gpiochip_get_data(gc);
84 u32 mask = BIT(irqd_to_hwirq(d));
85 u32 reg_both, reg_level, reg_type;
86
87 reg_type = readl(g->base + GPIO_INT_TYPE);
88 reg_level = readl(g->base + GPIO_INT_LEVEL);
89 reg_both = readl(g->base + GPIO_INT_BOTH_EDGE);
90
91 switch (type) {
92 case IRQ_TYPE_EDGE_BOTH:
93 irq_set_handler_locked(d, handle_edge_irq);
94 reg_type &= ~mask;
95 reg_both |= mask;
96 break;
97 case IRQ_TYPE_EDGE_RISING:
98 irq_set_handler_locked(d, handle_edge_irq);
99 reg_type &= ~mask;
100 reg_both &= ~mask;
101 reg_level &= ~mask;
102 break;
103 case IRQ_TYPE_EDGE_FALLING:
104 irq_set_handler_locked(d, handle_edge_irq);
105 reg_type &= ~mask;
106 reg_both &= ~mask;
107 reg_level |= mask;
108 break;
109 case IRQ_TYPE_LEVEL_HIGH:
110 irq_set_handler_locked(d, handle_level_irq);
111 reg_type |= mask;
112 reg_level &= ~mask;
113 break;
114 case IRQ_TYPE_LEVEL_LOW:
115 irq_set_handler_locked(d, handle_level_irq);
116 reg_type |= mask;
117 reg_level |= mask;
118 break;
119 default:
120 irq_set_handler_locked(d, handle_bad_irq);
121 return -EINVAL;
122 }
123
124 writel(reg_type, g->base + GPIO_INT_TYPE);
125 writel(reg_level, g->base + GPIO_INT_LEVEL);
126 writel(reg_both, g->base + GPIO_INT_BOTH_EDGE);
127
128 ftgpio_gpio_ack_irq(d);
129
130 return 0;
131 }
132
133 static struct irq_chip ftgpio_gpio_irqchip = {
134 .name = "FTGPIO010",
135 .irq_ack = ftgpio_gpio_ack_irq,
136 .irq_mask = ftgpio_gpio_mask_irq,
137 .irq_unmask = ftgpio_gpio_unmask_irq,
138 .irq_set_type = ftgpio_gpio_set_irq_type,
139 };
140
ftgpio_gpio_irq_handler(struct irq_desc * desc)141 static void ftgpio_gpio_irq_handler(struct irq_desc *desc)
142 {
143 struct gpio_chip *gc = irq_desc_get_handler_data(desc);
144 struct ftgpio_gpio *g = gpiochip_get_data(gc);
145 struct irq_chip *irqchip = irq_desc_get_chip(desc);
146 int offset;
147 unsigned long stat;
148
149 chained_irq_enter(irqchip, desc);
150
151 stat = readl(g->base + GPIO_INT_STAT_RAW);
152 if (stat)
153 for_each_set_bit(offset, &stat, gc->ngpio)
154 generic_handle_irq(irq_find_mapping(gc->irq.domain,
155 offset));
156
157 chained_irq_exit(irqchip, desc);
158 }
159
ftgpio_gpio_probe(struct platform_device * pdev)160 static int ftgpio_gpio_probe(struct platform_device *pdev)
161 {
162 struct device *dev = &pdev->dev;
163 struct resource *res;
164 struct ftgpio_gpio *g;
165 int irq;
166 int ret;
167
168 g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
169 if (!g)
170 return -ENOMEM;
171
172 g->dev = dev;
173
174 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
175 g->base = devm_ioremap_resource(dev, res);
176 if (IS_ERR(g->base))
177 return PTR_ERR(g->base);
178
179 irq = platform_get_irq(pdev, 0);
180 if (irq <= 0)
181 return irq ? irq : -EINVAL;
182
183 ret = bgpio_init(&g->gc, dev, 4,
184 g->base + GPIO_DATA_IN,
185 g->base + GPIO_DATA_SET,
186 g->base + GPIO_DATA_CLR,
187 g->base + GPIO_DIR,
188 NULL,
189 0);
190 if (ret) {
191 dev_err(dev, "unable to init generic GPIO\n");
192 return ret;
193 }
194 g->gc.label = "FTGPIO010";
195 g->gc.base = -1;
196 g->gc.parent = dev;
197 g->gc.owner = THIS_MODULE;
198 /* ngpio is set by bgpio_init() */
199
200 ret = devm_gpiochip_add_data(dev, &g->gc, g);
201 if (ret)
202 return ret;
203
204 /* Disable, unmask and clear all interrupts */
205 writel(0x0, g->base + GPIO_INT_EN);
206 writel(0x0, g->base + GPIO_INT_MASK);
207 writel(~0x0, g->base + GPIO_INT_CLR);
208
209 ret = gpiochip_irqchip_add(&g->gc, &ftgpio_gpio_irqchip,
210 0, handle_bad_irq,
211 IRQ_TYPE_NONE);
212 if (ret) {
213 dev_info(dev, "could not add irqchip\n");
214 return ret;
215 }
216 gpiochip_set_chained_irqchip(&g->gc, &ftgpio_gpio_irqchip,
217 irq, ftgpio_gpio_irq_handler);
218
219 dev_info(dev, "FTGPIO010 @%p registered\n", g->base);
220
221 return 0;
222 }
223
224 static const struct of_device_id ftgpio_gpio_of_match[] = {
225 {
226 .compatible = "cortina,gemini-gpio",
227 },
228 {
229 .compatible = "moxa,moxart-gpio",
230 },
231 {
232 .compatible = "faraday,ftgpio010",
233 },
234 {},
235 };
236
237 static struct platform_driver ftgpio_gpio_driver = {
238 .driver = {
239 .name = "ftgpio010-gpio",
240 .of_match_table = of_match_ptr(ftgpio_gpio_of_match),
241 },
242 .probe = ftgpio_gpio_probe,
243 };
244 builtin_platform_driver(ftgpio_gpio_driver);
245