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13a43fd9 JE |
1 | /* |
2 | * GPIO driver for NXP LPC18xx/43xx. | |
3 | * | |
4 | * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/clk.h> | |
13 | #include <linux/gpio/driver.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/of_gpio.h> | |
18 | #include <linux/pinctrl/consumer.h> | |
19 | #include <linux/platform_device.h> | |
20 | ||
21 | /* LPC18xx GPIO register offsets */ | |
22 | #define LPC18XX_REG_DIR(n) (0x2000 + n * sizeof(u32)) | |
23 | ||
24 | #define LPC18XX_MAX_PORTS 8 | |
25 | #define LPC18XX_PINS_PER_PORT 32 | |
26 | ||
27 | struct lpc18xx_gpio_chip { | |
28 | struct gpio_chip gpio; | |
29 | void __iomem *base; | |
30 | struct clk *clk; | |
31 | spinlock_t lock; | |
32 | }; | |
33 | ||
34 | static inline struct lpc18xx_gpio_chip *to_lpc18xx_gpio(struct gpio_chip *chip) | |
35 | { | |
36 | return container_of(chip, struct lpc18xx_gpio_chip, gpio); | |
37 | } | |
38 | ||
39 | static int lpc18xx_gpio_request(struct gpio_chip *chip, unsigned offset) | |
40 | { | |
41 | return pinctrl_request_gpio(offset); | |
42 | } | |
43 | ||
44 | static void lpc18xx_gpio_free(struct gpio_chip *chip, unsigned offset) | |
45 | { | |
46 | pinctrl_free_gpio(offset); | |
47 | } | |
48 | ||
49 | static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value) | |
50 | { | |
51 | struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip); | |
52 | writeb(value ? 1 : 0, gc->base + offset); | |
53 | } | |
54 | ||
55 | static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset) | |
56 | { | |
57 | struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip); | |
58 | return !!readb(gc->base + offset); | |
59 | } | |
60 | ||
61 | static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset, | |
62 | bool out) | |
63 | { | |
64 | struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip); | |
65 | unsigned long flags; | |
66 | u32 port, pin, dir; | |
67 | ||
68 | port = offset / LPC18XX_PINS_PER_PORT; | |
69 | pin = offset % LPC18XX_PINS_PER_PORT; | |
70 | ||
71 | spin_lock_irqsave(&gc->lock, flags); | |
72 | dir = readl(gc->base + LPC18XX_REG_DIR(port)); | |
73 | if (out) | |
74 | dir |= BIT(pin); | |
75 | else | |
76 | dir &= ~BIT(pin); | |
77 | writel(dir, gc->base + LPC18XX_REG_DIR(port)); | |
78 | spin_unlock_irqrestore(&gc->lock, flags); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static int lpc18xx_gpio_direction_input(struct gpio_chip *chip, | |
84 | unsigned offset) | |
85 | { | |
86 | return lpc18xx_gpio_direction(chip, offset, false); | |
87 | } | |
88 | ||
89 | static int lpc18xx_gpio_direction_output(struct gpio_chip *chip, | |
90 | unsigned offset, int value) | |
91 | { | |
92 | lpc18xx_gpio_set(chip, offset, value); | |
93 | return lpc18xx_gpio_direction(chip, offset, true); | |
94 | } | |
95 | ||
96 | static struct gpio_chip lpc18xx_chip = { | |
97 | .label = "lpc18xx/43xx-gpio", | |
98 | .request = lpc18xx_gpio_request, | |
99 | .free = lpc18xx_gpio_free, | |
100 | .direction_input = lpc18xx_gpio_direction_input, | |
101 | .direction_output = lpc18xx_gpio_direction_output, | |
102 | .set = lpc18xx_gpio_set, | |
103 | .get = lpc18xx_gpio_get, | |
104 | .ngpio = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT, | |
105 | .owner = THIS_MODULE, | |
106 | }; | |
107 | ||
108 | static int lpc18xx_gpio_probe(struct platform_device *pdev) | |
109 | { | |
110 | struct lpc18xx_gpio_chip *gc; | |
111 | struct resource *res; | |
112 | int ret; | |
113 | ||
114 | gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL); | |
115 | if (!gc) | |
116 | return -ENOMEM; | |
117 | ||
118 | gc->gpio = lpc18xx_chip; | |
119 | platform_set_drvdata(pdev, gc); | |
120 | ||
121 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
122 | gc->base = devm_ioremap_resource(&pdev->dev, res); | |
123 | if (IS_ERR(gc->base)) | |
124 | return PTR_ERR(gc->base); | |
125 | ||
126 | gc->clk = devm_clk_get(&pdev->dev, NULL); | |
127 | if (IS_ERR(gc->clk)) { | |
128 | dev_err(&pdev->dev, "input clock not found\n"); | |
129 | return PTR_ERR(gc->clk); | |
130 | } | |
131 | ||
132 | ret = clk_prepare_enable(gc->clk); | |
133 | if (ret) { | |
134 | dev_err(&pdev->dev, "unable to enable clock\n"); | |
135 | return ret; | |
136 | } | |
137 | ||
138 | spin_lock_init(&gc->lock); | |
139 | ||
140 | gc->gpio.dev = &pdev->dev; | |
141 | ||
142 | ret = gpiochip_add(&gc->gpio); | |
143 | if (ret) { | |
144 | dev_err(&pdev->dev, "failed to add gpio chip\n"); | |
145 | clk_disable_unprepare(gc->clk); | |
146 | return ret; | |
147 | } | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static int lpc18xx_gpio_remove(struct platform_device *pdev) | |
153 | { | |
154 | struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev); | |
155 | ||
156 | gpiochip_remove(&gc->gpio); | |
157 | clk_disable_unprepare(gc->clk); | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
162 | static const struct of_device_id lpc18xx_gpio_match[] = { | |
163 | { .compatible = "nxp,lpc1850-gpio" }, | |
164 | { } | |
165 | }; | |
166 | MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match); | |
167 | ||
168 | static struct platform_driver lpc18xx_gpio_driver = { | |
169 | .probe = lpc18xx_gpio_probe, | |
170 | .remove = lpc18xx_gpio_remove, | |
171 | .driver = { | |
172 | .name = "lpc18xx-gpio", | |
173 | .of_match_table = lpc18xx_gpio_match, | |
174 | }, | |
175 | }; | |
176 | module_platform_driver(lpc18xx_gpio_driver); | |
177 | ||
178 | MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>"); | |
179 | MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx"); | |
180 | MODULE_LICENSE("GPL v2"); |