scx200_i2c.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac
11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* linux/drivers/i2c/scx200_i2c.c 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> 41da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 51da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds National Semiconductor SCx200 I2C bus on GPIO pins 61da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 71da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds This program is free software; you can redistribute it and/or modify 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds it under the terms of the GNU General Public License as published by 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds the Free Software Foundation; either version 2 of the License, or 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds (at your option) any later version. 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds This program is distributed in the hope that it will be useful, 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds but WITHOUT ANY WARRANTY; without even the implied warranty of 161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds GNU General Public License for more details. 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds You should have received a copy of the GNU General Public License 201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds along with this program; if not, write to the Free Software 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds*/ 231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/config.h> 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/module.h> 261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/errno.h> 271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/kernel.h> 281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/init.h> 291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/i2c.h> 301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/i2c-algo-bit.h> 311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <asm/io.h> 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/scx200_gpio.h> 341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define NAME "scx200_i2c" 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_DESCRIPTION("NatSemi SCx200 I2C Driver"); 391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_LICENSE("GPL"); 401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int scl = CONFIG_SCx200_I2C_SCL; 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int sda = CONFIG_SCx200_I2C_SDA; 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(scl, int, 0); 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(scl, "GPIO line for SCL"); 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_param(sda, int, 0); 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsMODULE_PARM_DESC(sda, "GPIO line for SDA"); 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scx200_i2c_setscl(void *data, int state) 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_gpio_set(scl, state); 521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scx200_i2c_setsda(void *data, int state) 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_gpio_set(sda, state); 571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int scx200_i2c_getscl(void *data) 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return scx200_gpio_get(scl); 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int scx200_i2c_getsda(void *data) 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return scx200_gpio_get(sda); 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* ------------------------------------------------------------------------ 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Encapsulate the above functions in the correct operations structure. 711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This is only done when more than one hardware adapter is supported. 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct i2c_algo_bit_data scx200_i2c_data = { 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds NULL, 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_i2c_setsda, 771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_i2c_setscl, 781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_i2c_getsda, 791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_i2c_getscl, 801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 10, 10, 100, /* waits, timeout */ 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic struct i2c_adapter scx200_i2c_ops = { 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .owner = THIS_MODULE, 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .algo_data = &scx200_i2c_data, 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds .name = "NatSemi SCx200 I2C", 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic int scx200_i2c_init(void) 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds pr_debug(NAME ": NatSemi SCx200 I2C Driver\n"); 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!scx200_gpio_present()) { 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR NAME ": no SCx200 gpio pins available\n"); 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -ENODEV; 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds pr_debug(NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", scl, sda); 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (scl == -1 || sda == -1 || scl == sda) { 1011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR NAME ": scl and sda must be specified\n"); 1021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -EINVAL; 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Configure GPIOs as open collector outputs */ 1061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_gpio_configure(scl, ~2, 5); 1071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_gpio_configure(sda, ~2, 5); 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) { 1101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_ERR NAME ": adapter %s registration failed\n", 1111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds scx200_i2c_ops.name); 1121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return -ENODEV; 1131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return 0; 1161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void scx200_i2c_cleanup(void) 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds i2c_bit_del_bus(&scx200_i2c_ops); 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_init(scx200_i2c_init); 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsmodule_exit(scx200_i2c_cleanup); 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds Local variables: 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules" 1291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds c-basic-offset: 8 1301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds End: 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds*/ 132