16b65cd74SRussell King /* 26b65cd74SRussell King * i2c-versatile.c 36b65cd74SRussell King * 46b65cd74SRussell King * Copyright (C) 2006 ARM Ltd. 56b65cd74SRussell King * written by Russell King, Deep Blue Solutions Ltd. 66b65cd74SRussell King * 76b65cd74SRussell King * This program is free software; you can redistribute it and/or modify 86b65cd74SRussell King * it under the terms of the GNU General Public License version 2 as 96b65cd74SRussell King * published by the Free Software Foundation. 106b65cd74SRussell King */ 116b65cd74SRussell King #include <linux/kernel.h> 126b65cd74SRussell King #include <linux/module.h> 136b65cd74SRussell King #include <linux/i2c.h> 146b65cd74SRussell King #include <linux/i2c-algo-bit.h> 156b65cd74SRussell King #include <linux/init.h> 166b65cd74SRussell King #include <linux/platform_device.h> 175a0e3ad6STejun Heo #include <linux/slab.h> 1821782180SH Hartley Sweeten #include <linux/io.h> 196b65cd74SRussell King 206b65cd74SRussell King #define I2C_CONTROL 0x00 216b65cd74SRussell King #define I2C_CONTROLS 0x00 226b65cd74SRussell King #define I2C_CONTROLC 0x04 236b65cd74SRussell King #define SCL (1 << 0) 246b65cd74SRussell King #define SDA (1 << 1) 256b65cd74SRussell King 266b65cd74SRussell King struct i2c_versatile { 276b65cd74SRussell King struct i2c_adapter adap; 286b65cd74SRussell King struct i2c_algo_bit_data algo; 296b65cd74SRussell King void __iomem *base; 306b65cd74SRussell King }; 316b65cd74SRussell King 326b65cd74SRussell King static void i2c_versatile_setsda(void *data, int state) 336b65cd74SRussell King { 346b65cd74SRussell King struct i2c_versatile *i2c = data; 356b65cd74SRussell King 366b65cd74SRussell King writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); 376b65cd74SRussell King } 386b65cd74SRussell King 396b65cd74SRussell King static void i2c_versatile_setscl(void *data, int state) 406b65cd74SRussell King { 416b65cd74SRussell King struct i2c_versatile *i2c = data; 426b65cd74SRussell King 436b65cd74SRussell King writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); 446b65cd74SRussell King } 456b65cd74SRussell King 466b65cd74SRussell King static int i2c_versatile_getsda(void *data) 476b65cd74SRussell King { 486b65cd74SRussell King struct i2c_versatile *i2c = data; 496b65cd74SRussell King return !!(readl(i2c->base + I2C_CONTROL) & SDA); 506b65cd74SRussell King } 516b65cd74SRussell King 526b65cd74SRussell King static int i2c_versatile_getscl(void *data) 536b65cd74SRussell King { 546b65cd74SRussell King struct i2c_versatile *i2c = data; 556b65cd74SRussell King return !!(readl(i2c->base + I2C_CONTROL) & SCL); 566b65cd74SRussell King } 576b65cd74SRussell King 586b65cd74SRussell King static struct i2c_algo_bit_data i2c_versatile_algo = { 596b65cd74SRussell King .setsda = i2c_versatile_setsda, 606b65cd74SRussell King .setscl = i2c_versatile_setscl, 616b65cd74SRussell King .getsda = i2c_versatile_getsda, 626b65cd74SRussell King .getscl = i2c_versatile_getscl, 636b65cd74SRussell King .udelay = 30, 646b65cd74SRussell King .timeout = HZ, 656b65cd74SRussell King }; 666b65cd74SRussell King 676b65cd74SRussell King static int i2c_versatile_probe(struct platform_device *dev) 686b65cd74SRussell King { 696b65cd74SRussell King struct i2c_versatile *i2c; 706b65cd74SRussell King struct resource *r; 716b65cd74SRussell King int ret; 726b65cd74SRussell King 736b65cd74SRussell King r = platform_get_resource(dev, IORESOURCE_MEM, 0); 746b65cd74SRussell King if (!r) { 756b65cd74SRussell King ret = -EINVAL; 766b65cd74SRussell King goto err_out; 776b65cd74SRussell King } 786b65cd74SRussell King 79c6ffddeaSLinus Walleij if (!request_mem_region(r->start, resource_size(r), "versatile-i2c")) { 806b65cd74SRussell King ret = -EBUSY; 816b65cd74SRussell King goto err_out; 826b65cd74SRussell King } 836b65cd74SRussell King 846b65cd74SRussell King i2c = kzalloc(sizeof(struct i2c_versatile), GFP_KERNEL); 856b65cd74SRussell King if (!i2c) { 866b65cd74SRussell King ret = -ENOMEM; 876b65cd74SRussell King goto err_release; 886b65cd74SRussell King } 896b65cd74SRussell King 90c6ffddeaSLinus Walleij i2c->base = ioremap(r->start, resource_size(r)); 916b65cd74SRussell King if (!i2c->base) { 926b65cd74SRussell King ret = -ENOMEM; 936b65cd74SRussell King goto err_free; 946b65cd74SRussell King } 956b65cd74SRussell King 966b65cd74SRussell King writel(SCL | SDA, i2c->base + I2C_CONTROLS); 976b65cd74SRussell King 986b65cd74SRussell King i2c->adap.owner = THIS_MODULE; 996b65cd74SRussell King strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name)); 1006b65cd74SRussell King i2c->adap.algo_data = &i2c->algo; 1016b65cd74SRussell King i2c->adap.dev.parent = &dev->dev; 1026b65cd74SRussell King i2c->algo = i2c_versatile_algo; 1036b65cd74SRussell King i2c->algo.data = i2c; 1046b65cd74SRussell King 1052514cca0SCatalin Marinas if (dev->id >= 0) { 1062514cca0SCatalin Marinas /* static bus numbering */ 1072514cca0SCatalin Marinas i2c->adap.nr = dev->id; 1082514cca0SCatalin Marinas ret = i2c_bit_add_numbered_bus(&i2c->adap); 1092514cca0SCatalin Marinas } else 1102514cca0SCatalin Marinas /* dynamic bus numbering */ 1116b65cd74SRussell King ret = i2c_bit_add_bus(&i2c->adap); 1126b65cd74SRussell King if (ret >= 0) { 1136b65cd74SRussell King platform_set_drvdata(dev, i2c); 1146b65cd74SRussell King return 0; 1156b65cd74SRussell King } 1166b65cd74SRussell King 1176b65cd74SRussell King iounmap(i2c->base); 1186b65cd74SRussell King err_free: 1196b65cd74SRussell King kfree(i2c); 1206b65cd74SRussell King err_release: 121c6ffddeaSLinus Walleij release_mem_region(r->start, resource_size(r)); 1226b65cd74SRussell King err_out: 1236b65cd74SRussell King return ret; 1246b65cd74SRussell King } 1256b65cd74SRussell King 1266b65cd74SRussell King static int i2c_versatile_remove(struct platform_device *dev) 1276b65cd74SRussell King { 1286b65cd74SRussell King struct i2c_versatile *i2c = platform_get_drvdata(dev); 1296b65cd74SRussell King 1306b65cd74SRussell King platform_set_drvdata(dev, NULL); 1316b65cd74SRussell King 1326b65cd74SRussell King i2c_del_adapter(&i2c->adap); 1336b65cd74SRussell King return 0; 1346b65cd74SRussell King } 1356b65cd74SRussell King 1366b65cd74SRussell King static struct platform_driver i2c_versatile_driver = { 1376b65cd74SRussell King .probe = i2c_versatile_probe, 1386b65cd74SRussell King .remove = i2c_versatile_remove, 1396b65cd74SRussell King .driver = { 1406b65cd74SRussell King .name = "versatile-i2c", 1416b65cd74SRussell King .owner = THIS_MODULE, 1426b65cd74SRussell King }, 1436b65cd74SRussell King }; 1446b65cd74SRussell King 1456b65cd74SRussell King static int __init i2c_versatile_init(void) 1466b65cd74SRussell King { 1476b65cd74SRussell King return platform_driver_register(&i2c_versatile_driver); 1486b65cd74SRussell King } 1496b65cd74SRussell King 1506b65cd74SRussell King static void __exit i2c_versatile_exit(void) 1516b65cd74SRussell King { 1526b65cd74SRussell King platform_driver_unregister(&i2c_versatile_driver); 1536b65cd74SRussell King } 1546b65cd74SRussell King 1552514cca0SCatalin Marinas subsys_initcall(i2c_versatile_init); 1566b65cd74SRussell King module_exit(i2c_versatile_exit); 1576b65cd74SRussell King 1586b65cd74SRussell King MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); 1596b65cd74SRussell King MODULE_LICENSE("GPL"); 160add8eda7SKay Sievers MODULE_ALIAS("platform:versatile-i2c"); 161