1 /*
2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms of the GNU General Public License version 2 as published
4 * by the Free Software Foundation.
5 *
6 * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
7 */
8
9 #include <linux/slab.h>
10 #include <linux/export.h>
11 #include <linux/platform_device.h>
12 #include <linux/gpio.h>
13 #include <linux/ioport.h>
14 #include <linux/io.h>
15
16 #include <lantiq_soc.h>
17
18 #define LTQ_GPIO_OUT 0x00
19 #define LTQ_GPIO_IN 0x04
20 #define LTQ_GPIO_DIR 0x08
21 #define LTQ_GPIO_ALTSEL0 0x0C
22 #define LTQ_GPIO_ALTSEL1 0x10
23 #define LTQ_GPIO_OD 0x14
24
25 #define PINS_PER_PORT 16
26 #define MAX_PORTS 3
27
28 #define ltq_gpio_getbit(m, r, p) (!!(ltq_r32(m + r) & (1 << p)))
29 #define ltq_gpio_setbit(m, r, p) ltq_w32_mask(0, (1 << p), m + r)
30 #define ltq_gpio_clearbit(m, r, p) ltq_w32_mask((1 << p), 0, m + r)
31
32 struct ltq_gpio {
33 void __iomem *membase;
34 struct gpio_chip chip;
35 };
36
37 static struct ltq_gpio ltq_gpio_port[MAX_PORTS];
38
gpio_to_irq(unsigned int gpio)39 int gpio_to_irq(unsigned int gpio)
40 {
41 return -EINVAL;
42 }
43 EXPORT_SYMBOL(gpio_to_irq);
44
irq_to_gpio(unsigned int gpio)45 int irq_to_gpio(unsigned int gpio)
46 {
47 return -EINVAL;
48 }
49 EXPORT_SYMBOL(irq_to_gpio);
50
ltq_gpio_request(unsigned int pin,unsigned int alt0,unsigned int alt1,unsigned int dir,const char * name)51 int ltq_gpio_request(unsigned int pin, unsigned int alt0,
52 unsigned int alt1, unsigned int dir, const char *name)
53 {
54 int id = 0;
55
56 if (pin >= (MAX_PORTS * PINS_PER_PORT))
57 return -EINVAL;
58 if (gpio_request(pin, name)) {
59 pr_err("failed to setup lantiq gpio: %s\n", name);
60 return -EBUSY;
61 }
62 if (dir)
63 gpio_direction_output(pin, 1);
64 else
65 gpio_direction_input(pin);
66 while (pin >= PINS_PER_PORT) {
67 pin -= PINS_PER_PORT;
68 id++;
69 }
70 if (alt0)
71 ltq_gpio_setbit(ltq_gpio_port[id].membase,
72 LTQ_GPIO_ALTSEL0, pin);
73 else
74 ltq_gpio_clearbit(ltq_gpio_port[id].membase,
75 LTQ_GPIO_ALTSEL0, pin);
76 if (alt1)
77 ltq_gpio_setbit(ltq_gpio_port[id].membase,
78 LTQ_GPIO_ALTSEL1, pin);
79 else
80 ltq_gpio_clearbit(ltq_gpio_port[id].membase,
81 LTQ_GPIO_ALTSEL1, pin);
82 return 0;
83 }
84 EXPORT_SYMBOL(ltq_gpio_request);
85
ltq_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)86 static void ltq_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
87 {
88 struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
89
90 if (value)
91 ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_OUT, offset);
92 else
93 ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_OUT, offset);
94 }
95
ltq_gpio_get(struct gpio_chip * chip,unsigned int offset)96 static int ltq_gpio_get(struct gpio_chip *chip, unsigned int offset)
97 {
98 struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
99
100 return ltq_gpio_getbit(ltq_gpio->membase, LTQ_GPIO_IN, offset);
101 }
102
ltq_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)103 static int ltq_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
104 {
105 struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
106
107 ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_OD, offset);
108 ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_DIR, offset);
109
110 return 0;
111 }
112
ltq_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)113 static int ltq_gpio_direction_output(struct gpio_chip *chip,
114 unsigned int offset, int value)
115 {
116 struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
117
118 ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_OD, offset);
119 ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_DIR, offset);
120 ltq_gpio_set(chip, offset, value);
121
122 return 0;
123 }
124
ltq_gpio_req(struct gpio_chip * chip,unsigned offset)125 static int ltq_gpio_req(struct gpio_chip *chip, unsigned offset)
126 {
127 struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
128
129 ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_ALTSEL0, offset);
130 ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_ALTSEL1, offset);
131 return 0;
132 }
133
ltq_gpio_probe(struct platform_device * pdev)134 static int ltq_gpio_probe(struct platform_device *pdev)
135 {
136 struct resource *res;
137
138 if (pdev->id >= MAX_PORTS) {
139 dev_err(&pdev->dev, "invalid gpio port %d\n",
140 pdev->id);
141 return -EINVAL;
142 }
143 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
144 if (!res) {
145 dev_err(&pdev->dev, "failed to get memory for gpio port %d\n",
146 pdev->id);
147 return -ENOENT;
148 }
149 res = devm_request_mem_region(&pdev->dev, res->start,
150 resource_size(res), dev_name(&pdev->dev));
151 if (!res) {
152 dev_err(&pdev->dev,
153 "failed to request memory for gpio port %d\n",
154 pdev->id);
155 return -EBUSY;
156 }
157 ltq_gpio_port[pdev->id].membase = devm_ioremap_nocache(&pdev->dev,
158 res->start, resource_size(res));
159 if (!ltq_gpio_port[pdev->id].membase) {
160 dev_err(&pdev->dev, "failed to remap memory for gpio port %d\n",
161 pdev->id);
162 return -ENOMEM;
163 }
164 ltq_gpio_port[pdev->id].chip.label = "ltq_gpio";
165 ltq_gpio_port[pdev->id].chip.direction_input = ltq_gpio_direction_input;
166 ltq_gpio_port[pdev->id].chip.direction_output =
167 ltq_gpio_direction_output;
168 ltq_gpio_port[pdev->id].chip.get = ltq_gpio_get;
169 ltq_gpio_port[pdev->id].chip.set = ltq_gpio_set;
170 ltq_gpio_port[pdev->id].chip.request = ltq_gpio_req;
171 ltq_gpio_port[pdev->id].chip.base = PINS_PER_PORT * pdev->id;
172 ltq_gpio_port[pdev->id].chip.ngpio = PINS_PER_PORT;
173 platform_set_drvdata(pdev, <q_gpio_port[pdev->id]);
174 return gpiochip_add(<q_gpio_port[pdev->id].chip);
175 }
176
177 static struct platform_driver
178 ltq_gpio_driver = {
179 .probe = ltq_gpio_probe,
180 .driver = {
181 .name = "ltq_gpio",
182 .owner = THIS_MODULE,
183 },
184 };
185
ltq_gpio_init(void)186 int __init ltq_gpio_init(void)
187 {
188 int ret = platform_driver_register(<q_gpio_driver);
189
190 if (ret)
191 pr_info("ltq_gpio : Error registering platfom driver!");
192 return ret;
193 }
194
195 postcore_initcall(ltq_gpio_init);
196