diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/pca9698.c | 123 |
2 files changed, 124 insertions, 0 deletions
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index beca1da..f505813 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -31,6 +31,7 @@ COBJS-$(CONFIG_MARVELL_GPIO) += mvgpio.o COBJS-$(CONFIG_MARVELL_MFP) += mvmfp.o COBJS-$(CONFIG_MXC_GPIO) += mxc_gpio.o COBJS-$(CONFIG_PCA953X) += pca953x.o +COBJS-$(CONFIG_PCA9698) += pca9698.o COBJS-$(CONFIG_S5P) += s5p_gpio.o COBJS-$(CONFIG_TEGRA2_GPIO) += tegra2_gpio.o COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o diff --git a/drivers/gpio/pca9698.c b/drivers/gpio/pca9698.c new file mode 100644 index 0000000..b946efa --- /dev/null +++ b/drivers/gpio/pca9698.c @@ -0,0 +1,123 @@ +/* + * (C) Copyright 2011 + * Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* + * Driver for NXP's pca9698 40 bit I2C gpio expander + */ + +#include <common.h> +#include <i2c.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 + +static int pca9698_read40(u8 chip, u8 offset, u8 *buffer) +{ + u8 command = offset | 0x80; /* autoincrement */ + + return i2c_read(chip, command, 1, buffer, PCA9698_BUFFER_SIZE); +} + +static int pca9698_write40(u8 chip, u8 offset, u8 *buffer) +{ + u8 command = offset | 0x80; /* autoincrement */ + + return i2c_write(chip, 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_direction_input(u8 chip, unsigned offset) +{ + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(chip, PCA9698_REG_CONFIG, data); + if (res) + return res; + + pca9698_set_bit(offset, data, 1); + return pca9698_write40(chip, PCA9698_REG_CONFIG, data); +} + +int pca9698_direction_output(u8 chip, unsigned offset) +{ + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(chip, PCA9698_REG_CONFIG, data); + if (res) + return res; + + pca9698_set_bit(offset, data, 0); + return pca9698_write40(chip, PCA9698_REG_CONFIG, data); +} + +int pca9698_get_input(u8 chip, unsigned offset) +{ + unsigned config_byte = offset / 8; + unsigned config_bit = offset % 8; + unsigned value; + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(chip, PCA9698_REG_INPUT, data); + if (res) + return -1; + + value = data[config_byte] & (1 << config_bit); + + return !!value; +} + +int pca9698_set_output(u8 chip, unsigned offset, int value) +{ + u8 data[PCA9698_BUFFER_SIZE]; + int res; + + res = pca9698_read40(chip, PCA9698_REG_OUTPUT, data); + if (res) + return res; + + memset(data, sizeof(data), 0); + pca9698_set_bit(offset, data, value); + return pca9698_write40(chip, PCA9698_REG_OUTPUT, data); +} |