i2c-simtec.rar_simtec-i2c

/* * * * Simtec Generic I2C Controller * * * * 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 */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/io.h> #include <linux/i2c.h> #include <linux/i2c-algo-bit.h> struct simtec_i2c_data { struct resource *ioarea; void __iomem *reg; struct i2c_adapter adap; struct i2c_algo_bit_data bit; }; #define CMD_SET_SDA (1<<2) #define CMD_SET_SCL (1<<3) #define STATE_SDA (1<<0) #define STATE_SCL (1<<1) /* i2c bit-bus functions */ static void simtec_i2c_setsda(void *pw, int state) { struct simtec_i2c_data *pd = pw; writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg); } static void simtec_i2c_setscl(void *pw, int state) { struct simtec_i2c_data *pd = pw; writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg); } static int simtec_i2c_getsda(void *pw) { struct simtec_i2c_data *pd = pw; return readb(pd->reg) & STATE_SDA ? 1 : 0; } static int simtec_i2c_getscl(void *pw) { struct simtec_i2c_data *pd = pw; return readb(pd->reg) & STATE_SCL ? 1 : 0; } /* device registration */ static int simtec_i2c_probe(struct platform_device *dev) { struct simtec_i2c_data *pd; struct resource *res; int size; int ret; pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL); if (pd == NULL) { dev_err(&dev->dev, "cannot allocate private data\n"); return -ENOMEM; } platform_set_drvdata(dev, pd); res = platform_get_resource(dev, IORESOURCE_MEM, 0); if (res == NULL) { dev_err(&dev->dev, "cannot find IO resource\n"); ret = -ENOENT; goto err; } size = resource_size(res); pd->ioarea = request_mem_region(res->start, size, dev->name); if (pd->ioarea == NULL) { dev_err(&dev->dev, "cannot request IO\n"); ret = -ENXIO; goto err; } pd->reg = ioremap(res->start, size); if (pd->reg == NULL) { dev_err(&dev->dev, "cannot map IO\n"); ret = -ENXIO; goto err_res; } /* setup the private data */ pd->adap.owner = THIS_MODULE; pd->adap.algo_data = &pd->bit; pd->adap.dev.parent = &dev->dev; strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name)); pd->bit.data = pd; pd->bit.setsda = simtec_i2c_setsda; pd->bit.setscl = simtec_i2c_setscl; pd->bit.getsda = simtec_i2c_getsda; pd->bit.getscl = simtec_i2c_getscl; pd->bit.timeout = HZ; pd->bit.udelay = 20; ret = i2c_bit_add_bus(&pd->adap); if (ret) goto err_all; return 0; err_all: iounmap(pd->reg); err_res: release_resource(pd->ioarea); kfree(pd->ioarea); err: kfree(pd); return ret; } static int simtec_i2c_remove(struct platform_device *dev) { struct simtec_i2c_data *pd = platform_get_drvdata(dev); i2c_del_adapter(&pd->adap); iounmap(pd->reg); release_resource(pd->ioarea); kfree(pd->ioarea); kfree(pd); return 0; } /* device driver */ /* work with hotplug and coldplug */ MODULE_ALIAS("platform:simtec-i2c"); static struct platform_driver simtec_i2c_driver = { .driver = { .name = "simtec-i2c", .owner = THIS_MODULE, }, .probe = simtec_i2c_probe, .remove = simtec_i2c_remove, }; static int __init i2c_adap_simtec_init(void) { return platform_driver_register(&simtec_i2c_driver); } static void __exit i2c_adap_simtec_exit(void) { platform_driver_unregister(&simtec_i2c_driver); } module_init(i2c_adap_simtec_init); module_exit(i2c_adap_simtec_exit); MODULE_DESCRIPTION("Simtec Generic I2C Bus driver"); MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); MODULE_LICENSE("GPL");