1 /*
2 * Miscellaneous functions for IDT EB434 board
3 *
4 * Copyright 2004 IDT Inc. (rischelp@idt.com)
5 * Copyright 2006 Phil Sutter <n0-1@freewrt.org>
6 * Copyright 2007 Florian Fainelli <florian@openwrt.org>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
14 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
16 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
19 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 675 Mass Ave, Cambridge, MA 02139, USA.
27 */
28
29 #include <linux/kernel.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/export.h>
33 #include <linux/spinlock.h>
34 #include <linux/platform_device.h>
35 #include <linux/gpio/driver.h>
36
37 #include <asm/mach-rc32434/rb.h>
38 #include <asm/mach-rc32434/gpio.h>
39
40 #define GPIOBASE 0x050000
41 /* Offsets relative to GPIOBASE */
42 #define GPIOFUNC 0x00
43 #define GPIOCFG 0x04
44 #define GPIOD 0x08
45 #define GPIOILEVEL 0x0C
46 #define GPIOISTAT 0x10
47 #define GPIONMIEN 0x14
48 #define IMASK6 0x38
49
50 struct rb532_gpio_chip {
51 struct gpio_chip chip;
52 void __iomem *regbase;
53 };
54
55 static struct resource rb532_gpio_reg0_res[] = {
56 {
57 .name = "gpio_reg0",
58 .start = REGBASE + GPIOBASE,
59 .end = REGBASE + GPIOBASE + sizeof(struct rb532_gpio_reg) - 1,
60 .flags = IORESOURCE_MEM,
61 }
62 };
63
64 /* rb532_set_bit - sanely set a bit
65 *
66 * bitval: new value for the bit
67 * offset: bit index in the 4 byte address range
68 * ioaddr: 4 byte aligned address being altered
69 */
70 static inline void rb532_set_bit(unsigned bitval,
71 unsigned offset, void __iomem *ioaddr)
72 {
73 unsigned long flags;
74 u32 val;
75
76 local_irq_save(flags);
77
78 val = readl(ioaddr);
79 val &= ~(!bitval << offset); /* unset bit if bitval == 0 */
80 val |= (!!bitval << offset); /* set bit if bitval == 1 */
81 writel(val, ioaddr);
82
83 local_irq_restore(flags);
84 }
85
86 /* rb532_get_bit - read a bit
87 *
88 * returns the boolean state of the bit, which may be > 1
89 */
90 static inline int rb532_get_bit(unsigned offset, void __iomem *ioaddr)
91 {
92 return readl(ioaddr) & (1 << offset);
93 }
94
95 /*
96 * Return GPIO level */
97 static int rb532_gpio_get(struct gpio_chip *chip, unsigned offset)
98 {
99 struct rb532_gpio_chip *gpch;
100
101 gpch = gpiochip_get_data(chip);
102 return !!rb532_get_bit(offset, gpch->regbase + GPIOD);
103 }
104
105 /*
106 * Set output GPIO level
107 */
108 static void rb532_gpio_set(struct gpio_chip *chip,
109 unsigned offset, int value)
110 {
111 struct rb532_gpio_chip *gpch;
112
113 gpch = gpiochip_get_data(chip);
114 rb532_set_bit(value, offset, gpch->regbase + GPIOD);
115 }
116
117 /*
118 * Set GPIO direction to input
119 */
120 static int rb532_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
121 {
122 struct rb532_gpio_chip *gpch;
123
124 gpch = gpiochip_get_data(chip);
125
126 /* disable alternate function in case it's set */
127 rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC);
128
129 rb532_set_bit(0, offset, gpch->regbase + GPIOCFG);
130 return 0;
131 }
132
133 /*
134 * Set GPIO direction to output
135 */
136 static int rb532_gpio_direction_output(struct gpio_chip *chip,
137 unsigned offset, int value)
138 {
139 struct rb532_gpio_chip *gpch;
140
141 gpch = gpiochip_get_data(chip);
142
143 /* disable alternate function in case it's set */
144 rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC);
145
146 /* set the initial output value */
147 rb532_set_bit(value, offset, gpch->regbase + GPIOD);
148
149 rb532_set_bit(1, offset, gpch->regbase + GPIOCFG);
150 return 0;
151 }
152
153 static int rb532_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
154 {
155 return 8 + 4 * 32 + gpio;
156 }
157
158 static struct rb532_gpio_chip rb532_gpio_chip[] = {
159 [0] = {
160 .chip = {
161 .label = "gpio0",
162 .direction_input = rb532_gpio_direction_input,
163 .direction_output = rb532_gpio_direction_output,
164 .get = rb532_gpio_get,
165 .set = rb532_gpio_set,
166 .to_irq = rb532_gpio_to_irq,
167 .base = 0,
168 .ngpio = 32,
169 },
170 },
171 };
172
173 /*
174 * Set GPIO interrupt level
175 */
176 void rb532_gpio_set_ilevel(int bit, unsigned gpio)
177 {
178 rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOILEVEL);
179 }
180 EXPORT_SYMBOL(rb532_gpio_set_ilevel);
181
182 /*
183 * Set GPIO interrupt status
184 */
185 void rb532_gpio_set_istat(int bit, unsigned gpio)
186 {
187 rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOISTAT);
188 }
189 EXPORT_SYMBOL(rb532_gpio_set_istat);
190
191 /*
192 * Configure GPIO alternate function
193 */
194 void rb532_gpio_set_func(unsigned gpio)
195 {
196 rb532_set_bit(1, gpio, rb532_gpio_chip->regbase + GPIOFUNC);
197 }
198 EXPORT_SYMBOL(rb532_gpio_set_func);
199
200 static int __init rb532_gpio_init(void)
201 {
202 struct resource *r;
203
204 r = rb532_gpio_reg0_res;
205 rb532_gpio_chip->regbase = ioremap(r->start, resource_size(r));
206
207 if (!rb532_gpio_chip->regbase) {
208 printk(KERN_ERR "rb532: cannot remap GPIO register 0\n");
209 return -ENXIO;
210 }
211
212 /* Register our GPIO chip */
213 gpiochip_add_data(&rb532_gpio_chip->chip, rb532_gpio_chip);
214
215 return 0;
216 }
217 arch_initcall(rb532_gpio_init);
218
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