diff options
Diffstat (limited to 'arch/mips/pmcs-msp71xx/gpio.c')
| -rw-r--r-- | arch/mips/pmcs-msp71xx/gpio.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/arch/mips/pmcs-msp71xx/gpio.c b/arch/mips/pmcs-msp71xx/gpio.c new file mode 100644 index 0000000..aaccbe5 --- /dev/null +++ b/arch/mips/pmcs-msp71xx/gpio.c @@ -0,0 +1,216 @@ +/* + * Generic PMC MSP71xx GPIO handling. These base gpio are controlled by two + * types of registers. The data register sets the output level when in output + * mode and when in input mode will contain the value at the input. The config + * register sets the various modes for each gpio. + * + * 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/spinlock.h> +#include <linux/io.h> + +#define MSP71XX_CFG_OFFSET(gpio) (4 * (gpio)) +#define CONF_MASK 0x0F +#define MSP71XX_GPIO_INPUT 0x01 +#define MSP71XX_GPIO_OUTPUT 0x08 + +#define MSP71XX_GPIO_BASE 0x0B8400000L + +#define to_msp71xx_gpio_chip(c) container_of(c, struct msp71xx_gpio_chip, chip) + +static spinlock_t gpio_lock; + +/* + * struct msp71xx_gpio_chip - container for gpio chip and registers + * @chip: chip structure for the specified gpio bank + * @data_reg: register for reading and writing the gpio pin value + * @config_reg: register to set the mode for the gpio pin bank + * @out_drive_reg: register to set the output drive mode for the gpio pin bank + */ +struct msp71xx_gpio_chip { + struct gpio_chip chip; + void __iomem *data_reg; + void __iomem *config_reg; + void __iomem *out_drive_reg; +}; + +/* + * msp71xx_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_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct msp71xx_gpio_chip *msp_chip = to_msp71xx_gpio_chip(chip); + + return __raw_readl(msp_chip->data_reg) & (1 << offset); +} + +/* + * msp71xx_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_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct msp71xx_gpio_chip *msp_chip = to_msp71xx_gpio_chip(chip); + unsigned long flags; + u32 data; + + spin_lock_irqsave(&gpio_lock, flags); + + data = __raw_readl(msp_chip->data_reg); + if (value) + data |= (1 << offset); + else + data &= ~(1 << offset); + __raw_writel(data, msp_chip->data_reg); + + spin_unlock_irqrestore(&gpio_lock, flags); +} + +/* + * msp71xx_set_gpio_mode() - declare the mode for a gpio + * @chip: chip structure which controls the specified gpio + * @offset: gpio whose value will be assigned + * @mode: desired configuration for the gpio (see datasheet) + * + * It will set the gpio pin config to the @mode value passed in. + */ +static int msp71xx_set_gpio_mode(struct gpio_chip *chip, + unsigned offset, int mode) +{ + struct msp71xx_gpio_chip *msp_chip = to_msp71xx_gpio_chip(chip); + const unsigned bit_offset = MSP71XX_CFG_OFFSET(offset); + unsigned long flags; + u32 cfg; + + spin_lock_irqsave(&gpio_lock, flags); + + cfg = __raw_readl(msp_chip->config_reg); + cfg &= ~(CONF_MASK << bit_offset); + cfg |= (mode << bit_offset); + __raw_writel(cfg, msp_chip->config_reg); + + spin_unlock_irqrestore(&gpio_lock, flags); + + return 0; +} + +/* + * msp71xx_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_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + msp71xx_gpio_set(chip, offset, value); + + return msp71xx_set_gpio_mode(chip, offset, MSP71XX_GPIO_OUTPUT); +} + +/* + * msp71xx_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_direction_input(struct gpio_chip *chip, unsigned offset) +{ + return msp71xx_set_gpio_mode(chip, offset, MSP71XX_GPIO_INPUT); +} + +/* + * msp71xx_set_output_drive() - declare the output drive for the gpio line + * @gpio: gpio pin whose output drive you wish to modify + * @value: zero for active drain 1 for open drain drive + * + * This call will set the output drive mode for the @gpio to output. + */ +int msp71xx_set_output_drive(unsigned gpio, int value) +{ + unsigned long flags; + u32 data; + + if (gpio > 15 || gpio < 0) + return -EINVAL; + + spin_lock_irqsave(&gpio_lock, flags); + + data = __raw_readl((void __iomem *)(MSP71XX_GPIO_BASE + 0x190)); + if (value) + data |= (1 << gpio); + else + data &= ~(1 << gpio); + __raw_writel(data, (void __iomem *)(MSP71XX_GPIO_BASE + 0x190)); + + spin_unlock_irqrestore(&gpio_lock, flags); + + return 0; +} +EXPORT_SYMBOL(msp71xx_set_output_drive); + +#define MSP71XX_GPIO_BANK(name, dr, cr, base_gpio, num_gpio) \ +{ \ + .chip = { \ + .label = name, \ + .direction_input = msp71xx_direction_input, \ + .direction_output = msp71xx_direction_output, \ + .get = msp71xx_gpio_get, \ + .set = msp71xx_gpio_set, \ + .base = base_gpio, \ + .ngpio = num_gpio \ + }, \ + .data_reg = (void __iomem *)(MSP71XX_GPIO_BASE + dr), \ + .config_reg = (void __iomem *)(MSP71XX_GPIO_BASE + cr), \ + .out_drive_reg = (void __iomem *)(MSP71XX_GPIO_BASE + 0x190), \ +} + +/* + * struct msp71xx_gpio_banks[] - container array of gpio banks + * @chip: chip structure for the specified gpio bank + * @data_reg: register for reading and writing the gpio pin value + * @config_reg: register to set the mode for the gpio pin bank + * + * This array structure defines the gpio banks for the PMC MIPS Processor. + * We specify the bank name, the data register, the config register, base + * starting gpio number, and the number of gpios exposed by the bank. + */ +static struct msp71xx_gpio_chip msp71xx_gpio_banks[] = { + + MSP71XX_GPIO_BANK("GPIO_1_0", 0x170, 0x180, 0, 2), + MSP71XX_GPIO_BANK("GPIO_5_2", 0x174, 0x184, 2, 4), + MSP71XX_GPIO_BANK("GPIO_9_6", 0x178, 0x188, 6, 4), + MSP71XX_GPIO_BANK("GPIO_15_10", 0x17C, 0x18C, 10, 6), +}; + +void __init msp71xx_init_gpio(void) +{ + int i; + + spin_lock_init(&gpio_lock); + + for (i = 0; i < ARRAY_SIZE(msp71xx_gpio_banks); i++) + gpiochip_add(&msp71xx_gpio_banks[i].chip); +} |
