1bcda9f1eSBen Dooks /* 2bcda9f1eSBen Dooks * Copyright (C) 2005 Simtec Electronics 3bcda9f1eSBen Dooks * Ben Dooks <ben@simtec.co.uk> 4bcda9f1eSBen Dooks * 5bcda9f1eSBen Dooks * Simtec Generic I2C Controller 6bcda9f1eSBen Dooks * 7bcda9f1eSBen Dooks * This program is free software; you can redistribute it and/or modify 8bcda9f1eSBen Dooks * it under the terms of the GNU General Public License as published by 9bcda9f1eSBen Dooks * the Free Software Foundation; either version 2 of the License 10bcda9f1eSBen Dooks * 11bcda9f1eSBen Dooks * This program is distributed in the hope that it will be useful, 12bcda9f1eSBen Dooks * but WITHOUT ANY WARRANTY; without even the implied warranty of 13bcda9f1eSBen Dooks * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14bcda9f1eSBen Dooks * GNU General Public License for more details. 15bcda9f1eSBen Dooks * 16bcda9f1eSBen Dooks * You should have received a copy of the GNU General Public License 17bcda9f1eSBen Dooks * along with this program; if not, write to the Free Software 18bcda9f1eSBen Dooks * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19bcda9f1eSBen Dooks */ 20bcda9f1eSBen Dooks 21bcda9f1eSBen Dooks #include <linux/kernel.h> 22bcda9f1eSBen Dooks #include <linux/module.h> 23bcda9f1eSBen Dooks #include <linux/delay.h> 24bcda9f1eSBen Dooks #include <linux/platform_device.h> 255a0e3ad6STejun Heo #include <linux/slab.h> 2621782180SH Hartley Sweeten #include <linux/io.h> 27bcda9f1eSBen Dooks 28bcda9f1eSBen Dooks #include <linux/i2c.h> 29bcda9f1eSBen Dooks #include <linux/i2c-algo-bit.h> 30bcda9f1eSBen Dooks 31bcda9f1eSBen Dooks struct simtec_i2c_data { 32bcda9f1eSBen Dooks struct resource *ioarea; 33bcda9f1eSBen Dooks void __iomem *reg; 34bcda9f1eSBen Dooks struct i2c_adapter adap; 35bcda9f1eSBen Dooks struct i2c_algo_bit_data bit; 36bcda9f1eSBen Dooks }; 37bcda9f1eSBen Dooks 38bcda9f1eSBen Dooks #define CMD_SET_SDA (1<<2) 39bcda9f1eSBen Dooks #define CMD_SET_SCL (1<<3) 40bcda9f1eSBen Dooks 41bcda9f1eSBen Dooks #define STATE_SDA (1<<0) 42bcda9f1eSBen Dooks #define STATE_SCL (1<<1) 43bcda9f1eSBen Dooks 44bcda9f1eSBen Dooks /* i2c bit-bus functions */ 45bcda9f1eSBen Dooks 46bcda9f1eSBen Dooks static void simtec_i2c_setsda(void *pw, int state) 47bcda9f1eSBen Dooks { 48bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 49bcda9f1eSBen Dooks writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg); 50bcda9f1eSBen Dooks } 51bcda9f1eSBen Dooks 52bcda9f1eSBen Dooks static void simtec_i2c_setscl(void *pw, int state) 53bcda9f1eSBen Dooks { 54bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 55bcda9f1eSBen Dooks writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg); 56bcda9f1eSBen Dooks } 57bcda9f1eSBen Dooks 58bcda9f1eSBen Dooks static int simtec_i2c_getsda(void *pw) 59bcda9f1eSBen Dooks { 60bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 61bcda9f1eSBen Dooks return readb(pd->reg) & STATE_SDA ? 1 : 0; 62bcda9f1eSBen Dooks } 63bcda9f1eSBen Dooks 64bcda9f1eSBen Dooks static int simtec_i2c_getscl(void *pw) 65bcda9f1eSBen Dooks { 66bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 67bcda9f1eSBen Dooks return readb(pd->reg) & STATE_SCL ? 1 : 0; 68bcda9f1eSBen Dooks } 69bcda9f1eSBen Dooks 70bcda9f1eSBen Dooks /* device registration */ 71bcda9f1eSBen Dooks 72bcda9f1eSBen Dooks static int simtec_i2c_probe(struct platform_device *dev) 73bcda9f1eSBen Dooks { 74bcda9f1eSBen Dooks struct simtec_i2c_data *pd; 75bcda9f1eSBen Dooks struct resource *res; 76bcda9f1eSBen Dooks int size; 77bcda9f1eSBen Dooks int ret; 78bcda9f1eSBen Dooks 79bcda9f1eSBen Dooks pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL); 8046797a2aSJingoo Han if (pd == NULL) 81bcda9f1eSBen Dooks return -ENOMEM; 82bcda9f1eSBen Dooks 83bcda9f1eSBen Dooks platform_set_drvdata(dev, pd); 84bcda9f1eSBen Dooks 85bcda9f1eSBen Dooks res = platform_get_resource(dev, IORESOURCE_MEM, 0); 86bcda9f1eSBen Dooks if (res == NULL) { 87bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot find IO resource\n"); 88bcda9f1eSBen Dooks ret = -ENOENT; 89bcda9f1eSBen Dooks goto err; 90bcda9f1eSBen Dooks } 91bcda9f1eSBen Dooks 9259330825SJulia Lawall size = resource_size(res); 93bcda9f1eSBen Dooks 94bcda9f1eSBen Dooks pd->ioarea = request_mem_region(res->start, size, dev->name); 95bcda9f1eSBen Dooks if (pd->ioarea == NULL) { 96bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot request IO\n"); 97bcda9f1eSBen Dooks ret = -ENXIO; 98bcda9f1eSBen Dooks goto err; 99bcda9f1eSBen Dooks } 100bcda9f1eSBen Dooks 101bcda9f1eSBen Dooks pd->reg = ioremap(res->start, size); 102bcda9f1eSBen Dooks if (pd->reg == NULL) { 103bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot map IO\n"); 104bcda9f1eSBen Dooks ret = -ENXIO; 105bcda9f1eSBen Dooks goto err_res; 106bcda9f1eSBen Dooks } 107bcda9f1eSBen Dooks 108bcda9f1eSBen Dooks /* setup the private data */ 109bcda9f1eSBen Dooks 110bcda9f1eSBen Dooks pd->adap.owner = THIS_MODULE; 111bcda9f1eSBen Dooks pd->adap.algo_data = &pd->bit; 112bcda9f1eSBen Dooks pd->adap.dev.parent = &dev->dev; 113bcda9f1eSBen Dooks 114bcda9f1eSBen Dooks strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name)); 115bcda9f1eSBen Dooks 116bcda9f1eSBen Dooks pd->bit.data = pd; 117bcda9f1eSBen Dooks pd->bit.setsda = simtec_i2c_setsda; 118bcda9f1eSBen Dooks pd->bit.setscl = simtec_i2c_setscl; 119bcda9f1eSBen Dooks pd->bit.getsda = simtec_i2c_getsda; 120bcda9f1eSBen Dooks pd->bit.getscl = simtec_i2c_getscl; 121bcda9f1eSBen Dooks pd->bit.timeout = HZ; 122bcda9f1eSBen Dooks pd->bit.udelay = 20; 123bcda9f1eSBen Dooks 124bcda9f1eSBen Dooks ret = i2c_bit_add_bus(&pd->adap); 125bcda9f1eSBen Dooks if (ret) 126bcda9f1eSBen Dooks goto err_all; 127bcda9f1eSBen Dooks 128bcda9f1eSBen Dooks return 0; 129bcda9f1eSBen Dooks 130bcda9f1eSBen Dooks err_all: 131bcda9f1eSBen Dooks iounmap(pd->reg); 132bcda9f1eSBen Dooks 133bcda9f1eSBen Dooks err_res: 134bcda9f1eSBen Dooks release_resource(pd->ioarea); 135bcda9f1eSBen Dooks kfree(pd->ioarea); 136bcda9f1eSBen Dooks 137bcda9f1eSBen Dooks err: 138bcda9f1eSBen Dooks kfree(pd); 139bcda9f1eSBen Dooks return ret; 140bcda9f1eSBen Dooks } 141bcda9f1eSBen Dooks 142bcda9f1eSBen Dooks static int simtec_i2c_remove(struct platform_device *dev) 143bcda9f1eSBen Dooks { 144bcda9f1eSBen Dooks struct simtec_i2c_data *pd = platform_get_drvdata(dev); 145bcda9f1eSBen Dooks 146bcda9f1eSBen Dooks i2c_del_adapter(&pd->adap); 147bcda9f1eSBen Dooks 148bcda9f1eSBen Dooks iounmap(pd->reg); 149bcda9f1eSBen Dooks release_resource(pd->ioarea); 150bcda9f1eSBen Dooks kfree(pd->ioarea); 151bcda9f1eSBen Dooks kfree(pd); 152bcda9f1eSBen Dooks 153bcda9f1eSBen Dooks return 0; 154bcda9f1eSBen Dooks } 155bcda9f1eSBen Dooks 156bcda9f1eSBen Dooks /* device driver */ 157bcda9f1eSBen Dooks 158bcda9f1eSBen Dooks static struct platform_driver simtec_i2c_driver = { 159bcda9f1eSBen Dooks .driver = { 160bcda9f1eSBen Dooks .name = "simtec-i2c", 161bcda9f1eSBen Dooks .owner = THIS_MODULE, 162bcda9f1eSBen Dooks }, 163bcda9f1eSBen Dooks .probe = simtec_i2c_probe, 164bcda9f1eSBen Dooks .remove = simtec_i2c_remove, 165bcda9f1eSBen Dooks }; 166bcda9f1eSBen Dooks 167a3664b51SAxel Lin module_platform_driver(simtec_i2c_driver); 168bcda9f1eSBen Dooks 169bcda9f1eSBen Dooks MODULE_DESCRIPTION("Simtec Generic I2C Bus driver"); 170bcda9f1eSBen Dooks MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 171bcda9f1eSBen Dooks MODULE_LICENSE("GPL"); 172a3664b51SAxel Lin MODULE_ALIAS("platform:simtec-i2c"); 173