/* linux/drivers/i2c/busses/scx200_i2c.c Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> National Semiconductor SCx200 I2C bus on GPIO pins Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/i2c.h> #include <linux/i2c-algo-bit.h> #include <asm/io.h> #include <linux/scx200_gpio.h> #define NAME "scx200_i2c" MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver"); MODULE_LICENSE("GPL"); static int scl = CONFIG_SCx200_I2C_SCL; static int sda = CONFIG_SCx200_I2C_SDA; module_param(scl, int, 0); MODULE_PARM_DESC(scl, "GPIO line for SCL"); module_param(sda, int, 0); MODULE_PARM_DESC(sda, "GPIO line for SDA"); static void scx200_i2c_setscl(void *data, int state) { scx200_gpio_set(scl, state); } static void scx200_i2c_setsda(void *data, int state) { scx200_gpio_set(sda, state); } static int scx200_i2c_getscl(void *data) { return scx200_gpio_get(scl); } static int scx200_i2c_getsda(void *data) { return scx200_gpio_get(sda); } /* ------------------------------------------------------------------------ * Encapsulate the above functions in the correct operations structure. * This is only done when more than one hardware adapter is supported. */ static struct i2c_algo_bit_data scx200_i2c_data = { .setsda = scx200_i2c_setsda, .setscl = scx200_i2c_setscl, .getsda = scx200_i2c_getsda, .getscl = scx200_i2c_getscl, .udelay = 10, .timeout = 100, }; static struct i2c_adapter scx200_i2c_ops = { .owner = THIS_MODULE, .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, .id = I2C_HW_B_SCX200, .algo_data = &scx200_i2c_data, .name = "NatSemi SCx200 I2C", }; static int scx200_i2c_init(void) { pr_debug(NAME ": NatSemi SCx200 I2C Driver\n"); if (!scx200_gpio_present()) { printk(KERN_ERR NAME ": no SCx200 gpio pins available\n"); return -ENODEV; } pr_debug(NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", scl, sda); if (scl == -1 || sda == -1 || scl == sda) { printk(KERN_ERR NAME ": scl and sda must be specified\n"); return -EINVAL; } /* Configure GPIOs as open collector outputs */ scx200_gpio_configure(scl, ~2, 5); scx200_gpio_configure(sda, ~2, 5); if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) { printk(KERN_ERR NAME ": adapter %s registration failed\n", scx200_i2c_ops.name); return -ENODEV; } return 0; } static void scx200_i2c_cleanup(void) { i2c_del_adapter(&scx200_i2c_ops); } module_init(scx200_i2c_init); module_exit(scx200_i2c_cleanup); /* Local variables: compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules" c-basic-offset: 8 End: */