diff options
Diffstat (limited to 'arch/mips/pmc-sierra/msp71xx/gpio_extended.c')
| -rw-r--r-- | arch/mips/pmc-sierra/msp71xx/gpio_extended.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/mips/pmc-sierra/msp71xx/gpio_extended.c b/arch/mips/pmc-sierra/msp71xx/gpio_extended.c new file mode 100644 index 0000000..fc6dbc6 --- /dev/null +++ b/arch/mips/pmc-sierra/msp71xx/gpio_extended.c @@ -0,0 +1,148 @@ +/* + * @file /arch/mips/pmc-sierra/msp71xx/gpio_extended.c + * + * Generic PMC MSP71xx EXTENDED (EXD) GPIO handling. The extended gpio is + * a set of hardware registers that have no need for explicit locking as + * it is handled by unique method of writing individual set/clr bits. + * + * 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. + * + * @author Patrick Glass <patrickglass@gmail.com> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/gpio.h> +#include <linux/io.h> + +#define MSP71XX_DATA_OFFSET(gpio) (2 * (gpio)) +#define MSP71XX_READ_OFFSET(gpio) (MSP71XX_DATA_OFFSET(gpio) + 1) +#define MSP71XX_CFG_OUT_OFFSET(gpio) (MSP71XX_DATA_OFFSET(gpio) + 16) +#define MSP71XX_CFG_IN_OFFSET(gpio) (MSP71XX_CFG_OUT_OFFSET(gpio) + 1) + +#define MSP71XX_EXD_GPIO_BASE 0x0BC000000L + +#define to_msp71xx_exd_gpio_chip(c) \ + container_of(c, struct msp71xx_exd_gpio_chip, chip) + +/* + * struct msp71xx_exd_gpio_chip - container for gpio chip and registers + * @chip: chip structure for the specified gpio bank + * @reg: register for control and data of gpio pin + */ +struct msp71xx_exd_gpio_chip { + struct gpio_chip chip; + void __iomem *reg; +}; + +/* + * msp71xx_exd_gpio_get() - return the chip's gpio value + * @chip: chip structure which controls the specified gpio + * @offset: gpio whose value will be returned + * + * It will return 0 if gpio value is low and other if high. + */ +static int msp71xx_exd_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct msp71xx_exd_gpio_chip *msp71xx_chip = + to_msp71xx_exd_gpio_chip(chip); + const unsigned bit = MSP71XX_READ_OFFSET(offset); + + return __raw_readl(msp71xx_chip->reg) & (1 << bit); +} + +/* + * msp71xx_exd_gpio_set() - set the output value for the gpio + * @chip: chip structure who controls the specified gpio + * @offset: gpio whose value will be assigned + * @value: logic level to assign to the gpio initially + * + * This will set the gpio bit specified to the desired value. It will set the + * gpio pin low if value is 0 otherwise it will be high. + */ +static void msp71xx_exd_gpio_set(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct msp71xx_exd_gpio_chip *msp71xx_chip = + to_msp71xx_exd_gpio_chip(chip); + const unsigned bit = MSP71XX_DATA_OFFSET(offset); + + __raw_writel(1 << (bit + (value ? 1 : 0)), msp71xx_chip->reg); +} + +/* + * msp71xx_exd_direction_output() - declare the direction mode for a gpio + * @chip: chip structure which controls the specified gpio + * @offset: gpio whose value will be assigned + * @value: logic level to assign to the gpio initially + * + * This call will set the mode for the @gpio to output. It will set the + * gpio pin low if value is 0 otherwise it will be high. + */ +static int msp71xx_exd_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct msp71xx_exd_gpio_chip *msp71xx_chip = + to_msp71xx_exd_gpio_chip(chip); + + msp71xx_exd_gpio_set(chip, offset, value); + __raw_writel(1 << MSP71XX_CFG_OUT_OFFSET(offset), msp71xx_chip->reg); + return 0; +} + +/* + * msp71xx_exd_direction_input() - declare the direction mode for a gpio + * @chip: chip structure which controls the specified gpio + * @offset: gpio whose to which the value will be assigned + * + * This call will set the mode for the @gpio to input. + */ +static int msp71xx_exd_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct msp71xx_exd_gpio_chip *msp71xx_chip = + to_msp71xx_exd_gpio_chip(chip); + + __raw_writel(1 << MSP71XX_CFG_IN_OFFSET(offset), msp71xx_chip->reg); + return 0; +} + +#define MSP71XX_EXD_GPIO_BANK(name, exd_reg, base_gpio, num_gpio) \ +{ \ + .chip = { \ + .label = name, \ + .direction_input = msp71xx_exd_direction_input, \ + .direction_output = msp71xx_exd_direction_output, \ + .get = msp71xx_exd_gpio_get, \ + .set = msp71xx_exd_gpio_set, \ + .base = base_gpio, \ + .ngpio = num_gpio, \ + }, \ + .reg = (void __iomem *)(MSP71XX_EXD_GPIO_BASE + exd_reg), \ +} + +/* + * struct msp71xx_exd_gpio_banks[] - container array of gpio banks + * @chip: chip structure for the specified gpio bank + * @reg: register for reading and writing the gpio pin value + * + * This array structure defines the extended gpio banks for the + * PMC MIPS Processor. We specify the bank name, the data/config + * register,the base starting gpio number, and the number of + * gpios exposed by the bank of gpios. + */ +static struct msp71xx_exd_gpio_chip msp71xx_exd_gpio_banks[] = { + + MSP71XX_EXD_GPIO_BANK("GPIO_23_16", 0x188, 16, 8), + MSP71XX_EXD_GPIO_BANK("GPIO_27_24", 0x18C, 24, 4), +}; + +void __init msp71xx_init_gpio_extended(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(msp71xx_exd_gpio_banks); i++) + gpiochip_add(&msp71xx_exd_gpio_banks[i].chip); +} |