diff options
Diffstat (limited to 'arch/arm/plat-samsung/gpiolib.c')
| -rw-r--r-- | arch/arm/plat-samsung/gpiolib.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/gpiolib.c b/arch/arm/plat-samsung/gpiolib.c new file mode 100644 index 000000000000..8a8ba8bc1d96 --- /dev/null +++ b/arch/arm/plat-samsung/gpiolib.c @@ -0,0 +1,199 @@ +/* arch/arm/plat-samsung/gpiolib.c + * + * Copyright 2008 Openmoko, Inc. + * Copyright 2008 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * http://armlinux.simtec.co.uk/ + * + * Copyright (c) 2009 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * SAMSUNG - GPIOlib support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <mach/gpio.h> +#include <plat/gpio-core.h> +#include <plat/gpio-cfg.h> +#include <plat/gpio-cfg-helpers.h> + +#ifndef DEBUG_GPIO +#define gpio_dbg(x...) do { } while (0) +#else +#define gpio_dbg(x...) printk(KERN_DEBUG x) +#endif + +/* The samsung_gpiolib_4bit routines are to control the gpio banks where + * the gpio configuration register (GPxCON) has 4 bits per GPIO, as the + * following example: + * + * base + 0x00: Control register, 4 bits per gpio + * gpio n: 4 bits starting at (4*n) + * 0000 = input, 0001 = output, others mean special-function + * base + 0x04: Data register, 1 bit per gpio + * bit n: data bit n + * + * Note, since the data register is one bit per gpio and is at base + 0x4 + * we can use s3c_gpiolib_get and s3c_gpiolib_set to change the state of + * the output. +*/ + +static int samsung_gpiolib_4bit_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); + void __iomem *base = ourchip->base; + unsigned long con; + + con = __raw_readl(base + GPIOCON_OFF); + con &= ~(0xf << con_4bit_shift(offset)); + __raw_writel(con, base + GPIOCON_OFF); + + gpio_dbg("%s: %p: CON now %08lx\n", __func__, base, con); + + return 0; +} + +static int samsung_gpiolib_4bit_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); + void __iomem *base = ourchip->base; + unsigned long con; + unsigned long dat; + + con = __raw_readl(base + GPIOCON_OFF); + con &= ~(0xf << con_4bit_shift(offset)); + con |= 0x1 << con_4bit_shift(offset); + + dat = __raw_readl(base + GPIODAT_OFF); + + if (value) + dat |= 1 << offset; + else + dat &= ~(1 << offset); + + __raw_writel(dat, base + GPIODAT_OFF); + __raw_writel(con, base + GPIOCON_OFF); + __raw_writel(dat, base + GPIODAT_OFF); + + gpio_dbg("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat); + + return 0; +} + +/* The next set of routines are for the case where the GPIO configuration + * registers are 4 bits per GPIO but there is more than one register (the + * bank has more than 8 GPIOs. + * + * This case is the similar to the 4 bit case, but the registers are as + * follows: + * + * base + 0x00: Control register, 4 bits per gpio (lower 8 GPIOs) + * gpio n: 4 bits starting at (4*n) + * 0000 = input, 0001 = output, others mean special-function + * base + 0x04: Control register, 4 bits per gpio (up to 8 additions GPIOs) + * gpio n: 4 bits starting at (4*n) + * 0000 = input, 0001 = output, others mean special-function + * base + 0x08: Data register, 1 bit per gpio + * bit n: data bit n + * + * To allow us to use the s3c_gpiolib_get and s3c_gpiolib_set routines we + * store the 'base + 0x4' address so that these routines see the data + * register at ourchip->base + 0x04. + */ + +static int samsung_gpiolib_4bit2_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); + void __iomem *base = ourchip->base; + void __iomem *regcon = base; + unsigned long con; + + if (offset > 7) + offset -= 8; + else + regcon -= 4; + + con = __raw_readl(regcon); + con &= ~(0xf << con_4bit_shift(offset)); + __raw_writel(con, regcon); + + gpio_dbg("%s: %p: CON %08lx\n", __func__, base, con); + + return 0; +} + +static int samsung_gpiolib_4bit2_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); + void __iomem *base = ourchip->base; + void __iomem *regcon = base; + unsigned long con; + unsigned long dat; + unsigned con_offset = offset; + + if (con_offset > 7) + con_offset -= 8; + else + regcon -= 4; + + con = __raw_readl(regcon); + con &= ~(0xf << con_4bit_shift(con_offset)); + con |= 0x1 << con_4bit_shift(con_offset); + + dat = __raw_readl(base + GPIODAT_OFF); + + if (value) + dat |= 1 << offset; + else + dat &= ~(1 << offset); + + __raw_writel(dat, base + GPIODAT_OFF); + __raw_writel(con, regcon); + __raw_writel(dat, base + GPIODAT_OFF); + + gpio_dbg("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat); + + return 0; +} + +void __init samsung_gpiolib_add_4bit(struct s3c_gpio_chip *chip) +{ + chip->chip.direction_input = samsung_gpiolib_4bit_input; + chip->chip.direction_output = samsung_gpiolib_4bit_output; + chip->pm = __gpio_pm(&s3c_gpio_pm_4bit); +} + +void __init samsung_gpiolib_add_4bit2(struct s3c_gpio_chip *chip) +{ + chip->chip.direction_input = samsung_gpiolib_4bit2_input; + chip->chip.direction_output = samsung_gpiolib_4bit2_output; + chip->pm = __gpio_pm(&s3c_gpio_pm_4bit); +} + +void __init samsung_gpiolib_add_4bit_chips(struct s3c_gpio_chip *chip, + int nr_chips) +{ + for (; nr_chips > 0; nr_chips--, chip++) { + samsung_gpiolib_add_4bit(chip); + s3c_gpiolib_add(chip); + } +} + +void __init samsung_gpiolib_add_4bit2_chips(struct s3c_gpio_chip *chip, + int nr_chips) +{ + for (; nr_chips > 0; nr_chips--, chip++) { + samsung_gpiolib_add_4bit2(chip); + s3c_gpiolib_add(chip); + } +} |
