diff options
Diffstat (limited to 'qemu/roms/u-boot/drivers/gpio/pca9698.c')
-rw-r--r-- | qemu/roms/u-boot/drivers/gpio/pca9698.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/drivers/gpio/pca9698.c b/qemu/roms/u-boot/drivers/gpio/pca9698.c new file mode 100644 index 000000000..3152bf6df --- /dev/null +++ b/qemu/roms/u-boot/drivers/gpio/pca9698.c @@ -0,0 +1,127 @@ +/* + * (C) Copyright 2011 + * Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/* + * Driver for NXP's pca9698 40 bit I2C gpio expander + */ + +#include <common.h> +#include <i2c.h> +#include <asm/errno.h> +#include <pca9698.h> + +/* + * The pca9698 registers + */ + +#define PCA9698_REG_INPUT 0x00 +#define PCA9698_REG_OUTPUT 0x08 +#define PCA9698_REG_POLARITY 0x10 +#define PCA9698_REG_CONFIG 0x18 + +#define PCA9698_BUFFER_SIZE 5 +#define PCA9698_GPIO_COUNT 40 + +static int pca9698_read40(u8 addr, u8 offset, u8 *buffer) +{ + u8 command = offset | 0x80; /* autoincrement */ + + return i2c_read(addr, command, 1, buffer, PCA9698_BUFFER_SIZE); +} + +static int pca9698_write40(u8 addr, u8 offset, u8 *buffer) +{ + u8 command = offset | 0x80; /* autoincrement */ + + return i2c_write(addr, command, 1, buffer, PCA9698_BUFFER_SIZE); +} + +static void pca9698_set_bit(unsigned gpio, u8 *buffer, unsigned value) +{ + unsigned byte = gpio / 8; + unsigned bit = gpio % 8; + + if (value) + buffer[byte] |= (1 << bit); + else + buffer[byte] &= ~(1 << bit); +} + +int pca9698_request(unsigned gpio, const char *label) +{ + if (gpio >= PCA9698_GPIO_COUNT) + return -EINVAL; + + return 0; +} + +void pca9698_free(unsigned gpio) +{ +} + +int pca9698_direction_input(u8 addr, unsigned gpio) +{ + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(addr, PCA9698_REG_CONFIG, data); + if (res) + return res; + + pca9698_set_bit(gpio, data, 1); + + return pca9698_write40(addr, PCA9698_REG_CONFIG, data); +} + +int pca9698_direction_output(u8 addr, unsigned gpio, int value) +{ + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_set_value(addr, gpio, value); + if (res) + return res; + + res = pca9698_read40(addr, PCA9698_REG_CONFIG, data); + if (res) + return res; + + pca9698_set_bit(gpio, data, 0); + + return pca9698_write40(addr, PCA9698_REG_CONFIG, data); +} + +int pca9698_get_value(u8 addr, unsigned gpio) +{ + unsigned config_byte = gpio / 8; + unsigned config_bit = gpio % 8; + unsigned value; + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(addr, PCA9698_REG_INPUT, data); + if (res) + return -1; + + value = data[config_byte] & (1 << config_bit); + + return !!value; +} + +int pca9698_set_value(u8 addr, unsigned gpio, int value) +{ + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(addr, PCA9698_REG_OUTPUT, data); + if (res) + return res; + + pca9698_set_bit(gpio, data, value); + + return pca9698_write40(addr, PCA9698_REG_OUTPUT, data); +} |