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 struct rb532_gpio_chip { 41 struct gpio_chip chip; 42 void __iomem *regbase; 43 }; 44 45 static struct resource rb532_gpio_reg0_res[] = { 46 { 47 .name = "gpio_reg0", 48 .start = REGBASE + GPIOBASE, 49 .end = REGBASE + GPIOBASE + sizeof(struct rb532_gpio_reg) - 1, 50 .flags = IORESOURCE_MEM, 51 } 52 }; 53 54 /* rb532_set_bit - sanely set a bit 55 * 56 * bitval: new value for the bit 57 * offset: bit index in the 4 byte address range 58 * ioaddr: 4 byte aligned address being altered 59 */ 60 static inline void rb532_set_bit(unsigned bitval, 61 unsigned offset, void __iomem *ioaddr) 62 { 63 unsigned long flags; 64 u32 val; 65 66 local_irq_save(flags); 67 68 val = readl(ioaddr); 69 val &= ~(!bitval << offset); /* unset bit if bitval == 0 */ 70 val |= (!!bitval << offset); /* set bit if bitval == 1 */ 71 writel(val, ioaddr); 72 73 local_irq_restore(flags); 74 } 75 76 /* rb532_get_bit - read a bit 77 * 78 * returns the boolean state of the bit, which may be > 1 79 */ 80 static inline int rb532_get_bit(unsigned offset, void __iomem *ioaddr) 81 { 82 return readl(ioaddr) & (1 << offset); 83 } 84 85 /* 86 * Return GPIO level */ 87 static int rb532_gpio_get(struct gpio_chip *chip, unsigned offset) 88 { 89 struct rb532_gpio_chip *gpch; 90 91 gpch = gpiochip_get_data(chip); 92 return !!rb532_get_bit(offset, gpch->regbase + GPIOD); 93 } 94 95 /* 96 * Set output GPIO level 97 */ 98 static void rb532_gpio_set(struct gpio_chip *chip, 99 unsigned offset, int value) 100 { 101 struct rb532_gpio_chip *gpch; 102 103 gpch = gpiochip_get_data(chip); 104 rb532_set_bit(value, offset, gpch->regbase + GPIOD); 105 } 106 107 /* 108 * Set GPIO direction to input 109 */ 110 static int rb532_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 111 { 112 struct rb532_gpio_chip *gpch; 113 114 gpch = gpiochip_get_data(chip); 115 116 /* disable alternate function in case it's set */ 117 rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC); 118 119 rb532_set_bit(0, offset, gpch->regbase + GPIOCFG); 120 return 0; 121 } 122 123 /* 124 * Set GPIO direction to output 125 */ 126 static int rb532_gpio_direction_output(struct gpio_chip *chip, 127 unsigned offset, int value) 128 { 129 struct rb532_gpio_chip *gpch; 130 131 gpch = gpiochip_get_data(chip); 132 133 /* disable alternate function in case it's set */ 134 rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC); 135 136 /* set the initial output value */ 137 rb532_set_bit(value, offset, gpch->regbase + GPIOD); 138 139 rb532_set_bit(1, offset, gpch->regbase + GPIOCFG); 140 return 0; 141 } 142 143 static int rb532_gpio_to_irq(struct gpio_chip *chip, unsigned gpio) 144 { 145 return 8 + 4 * 32 + gpio; 146 } 147 148 static struct rb532_gpio_chip rb532_gpio_chip[] = { 149 [0] = { 150 .chip = { 151 .label = "gpio0", 152 .direction_input = rb532_gpio_direction_input, 153 .direction_output = rb532_gpio_direction_output, 154 .get = rb532_gpio_get, 155 .set = rb532_gpio_set, 156 .to_irq = rb532_gpio_to_irq, 157 .base = 0, 158 .ngpio = 32, 159 }, 160 }, 161 }; 162 163 /* 164 * Set GPIO interrupt level 165 */ 166 void rb532_gpio_set_ilevel(int bit, unsigned gpio) 167 { 168 rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOILEVEL); 169 } 170 EXPORT_SYMBOL(rb532_gpio_set_ilevel); 171 172 /* 173 * Set GPIO interrupt status 174 */ 175 void rb532_gpio_set_istat(int bit, unsigned gpio) 176 { 177 rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOISTAT); 178 } 179 EXPORT_SYMBOL(rb532_gpio_set_istat); 180 181 /* 182 * Configure GPIO alternate function 183 */ 184 void rb532_gpio_set_func(unsigned gpio) 185 { 186 rb532_set_bit(1, gpio, rb532_gpio_chip->regbase + GPIOFUNC); 187 } 188 EXPORT_SYMBOL(rb532_gpio_set_func); 189 190 int __init rb532_gpio_init(void) 191 { 192 struct resource *r; 193 194 r = rb532_gpio_reg0_res; 195 rb532_gpio_chip->regbase = ioremap_nocache(r->start, resource_size(r)); 196 197 if (!rb532_gpio_chip->regbase) { 198 printk(KERN_ERR "rb532: cannot remap GPIO register 0\n"); 199 return -ENXIO; 200 } 201 202 /* Register our GPIO chip */ 203 gpiochip_add_data(&rb532_gpio_chip->chip, rb532_gpio_chip); 204 205 return 0; 206 } 207 arch_initcall(rb532_gpio_init); 208