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 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