12504ba9fSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2bcda9f1eSBen Dooks /* 3bcda9f1eSBen Dooks * Copyright (C) 2005 Simtec Electronics 4bcda9f1eSBen Dooks * Ben Dooks <ben@simtec.co.uk> 5bcda9f1eSBen Dooks * 6bcda9f1eSBen Dooks * Simtec Generic I2C Controller 7bcda9f1eSBen Dooks */ 8bcda9f1eSBen Dooks 9bcda9f1eSBen Dooks #include <linux/kernel.h> 10bcda9f1eSBen Dooks #include <linux/module.h> 11bcda9f1eSBen Dooks #include <linux/delay.h> 12bcda9f1eSBen Dooks #include <linux/platform_device.h> 135a0e3ad6STejun Heo #include <linux/slab.h> 1421782180SH Hartley Sweeten #include <linux/io.h> 15bcda9f1eSBen Dooks 16bcda9f1eSBen Dooks #include <linux/i2c.h> 17bcda9f1eSBen Dooks #include <linux/i2c-algo-bit.h> 18bcda9f1eSBen Dooks 19bcda9f1eSBen Dooks struct simtec_i2c_data { 20bcda9f1eSBen Dooks struct resource *ioarea; 21bcda9f1eSBen Dooks void __iomem *reg; 22bcda9f1eSBen Dooks struct i2c_adapter adap; 23bcda9f1eSBen Dooks struct i2c_algo_bit_data bit; 24bcda9f1eSBen Dooks }; 25bcda9f1eSBen Dooks 26bcda9f1eSBen Dooks #define CMD_SET_SDA (1<<2) 27bcda9f1eSBen Dooks #define CMD_SET_SCL (1<<3) 28bcda9f1eSBen Dooks 29bcda9f1eSBen Dooks #define STATE_SDA (1<<0) 30bcda9f1eSBen Dooks #define STATE_SCL (1<<1) 31bcda9f1eSBen Dooks 32bcda9f1eSBen Dooks /* i2c bit-bus functions */ 33bcda9f1eSBen Dooks 34bcda9f1eSBen Dooks static void simtec_i2c_setsda(void *pw, int state) 35bcda9f1eSBen Dooks { 36bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 37bcda9f1eSBen Dooks writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg); 38bcda9f1eSBen Dooks } 39bcda9f1eSBen Dooks 40bcda9f1eSBen Dooks static void simtec_i2c_setscl(void *pw, int state) 41bcda9f1eSBen Dooks { 42bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 43bcda9f1eSBen Dooks writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg); 44bcda9f1eSBen Dooks } 45bcda9f1eSBen Dooks 46bcda9f1eSBen Dooks static int simtec_i2c_getsda(void *pw) 47bcda9f1eSBen Dooks { 48bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 49bcda9f1eSBen Dooks return readb(pd->reg) & STATE_SDA ? 1 : 0; 50bcda9f1eSBen Dooks } 51bcda9f1eSBen Dooks 52bcda9f1eSBen Dooks static int simtec_i2c_getscl(void *pw) 53bcda9f1eSBen Dooks { 54bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw; 55bcda9f1eSBen Dooks return readb(pd->reg) & STATE_SCL ? 1 : 0; 56bcda9f1eSBen Dooks } 57bcda9f1eSBen Dooks 58bcda9f1eSBen Dooks /* device registration */ 59bcda9f1eSBen Dooks 60bcda9f1eSBen Dooks static int simtec_i2c_probe(struct platform_device *dev) 61bcda9f1eSBen Dooks { 62bcda9f1eSBen Dooks struct simtec_i2c_data *pd; 63bcda9f1eSBen Dooks struct resource *res; 64bcda9f1eSBen Dooks int size; 65bcda9f1eSBen Dooks int ret; 66bcda9f1eSBen Dooks 67bcda9f1eSBen Dooks pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL); 6846797a2aSJingoo Han if (pd == NULL) 69bcda9f1eSBen Dooks return -ENOMEM; 70bcda9f1eSBen Dooks 71bcda9f1eSBen Dooks platform_set_drvdata(dev, pd); 72bcda9f1eSBen Dooks 73bcda9f1eSBen Dooks res = platform_get_resource(dev, IORESOURCE_MEM, 0); 74bcda9f1eSBen Dooks if (res == NULL) { 75bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot find IO resource\n"); 76bcda9f1eSBen Dooks ret = -ENOENT; 77bcda9f1eSBen Dooks goto err; 78bcda9f1eSBen Dooks } 79bcda9f1eSBen Dooks 8059330825SJulia Lawall size = resource_size(res); 81bcda9f1eSBen Dooks 82bcda9f1eSBen Dooks pd->ioarea = request_mem_region(res->start, size, dev->name); 83bcda9f1eSBen Dooks if (pd->ioarea == NULL) { 84bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot request IO\n"); 85bcda9f1eSBen Dooks ret = -ENXIO; 86bcda9f1eSBen Dooks goto err; 87bcda9f1eSBen Dooks } 88bcda9f1eSBen Dooks 89bcda9f1eSBen Dooks pd->reg = ioremap(res->start, size); 90bcda9f1eSBen Dooks if (pd->reg == NULL) { 91bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot map IO\n"); 92bcda9f1eSBen Dooks ret = -ENXIO; 93bcda9f1eSBen Dooks goto err_res; 94bcda9f1eSBen Dooks } 95bcda9f1eSBen Dooks 96bcda9f1eSBen Dooks /* setup the private data */ 97bcda9f1eSBen Dooks 98bcda9f1eSBen Dooks pd->adap.owner = THIS_MODULE; 99bcda9f1eSBen Dooks pd->adap.algo_data = &pd->bit; 100bcda9f1eSBen Dooks pd->adap.dev.parent = &dev->dev; 101bcda9f1eSBen Dooks 102bcda9f1eSBen Dooks strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name)); 103bcda9f1eSBen Dooks 104bcda9f1eSBen Dooks pd->bit.data = pd; 105bcda9f1eSBen Dooks pd->bit.setsda = simtec_i2c_setsda; 106bcda9f1eSBen Dooks pd->bit.setscl = simtec_i2c_setscl; 107bcda9f1eSBen Dooks pd->bit.getsda = simtec_i2c_getsda; 108bcda9f1eSBen Dooks pd->bit.getscl = simtec_i2c_getscl; 109bcda9f1eSBen Dooks pd->bit.timeout = HZ; 110bcda9f1eSBen Dooks pd->bit.udelay = 20; 111bcda9f1eSBen Dooks 112bcda9f1eSBen Dooks ret = i2c_bit_add_bus(&pd->adap); 113bcda9f1eSBen Dooks if (ret) 114bcda9f1eSBen Dooks goto err_all; 115bcda9f1eSBen Dooks 116bcda9f1eSBen Dooks return 0; 117bcda9f1eSBen Dooks 118bcda9f1eSBen Dooks err_all: 119bcda9f1eSBen Dooks iounmap(pd->reg); 120bcda9f1eSBen Dooks 121bcda9f1eSBen Dooks err_res: 12242543aebSAnton Vasilyev release_mem_region(pd->ioarea->start, size); 123bcda9f1eSBen Dooks 124bcda9f1eSBen Dooks err: 125bcda9f1eSBen Dooks kfree(pd); 126bcda9f1eSBen Dooks return ret; 127bcda9f1eSBen Dooks } 128bcda9f1eSBen Dooks 129bcda9f1eSBen Dooks static int simtec_i2c_remove(struct platform_device *dev) 130bcda9f1eSBen Dooks { 131bcda9f1eSBen Dooks struct simtec_i2c_data *pd = platform_get_drvdata(dev); 132bcda9f1eSBen Dooks 133bcda9f1eSBen Dooks i2c_del_adapter(&pd->adap); 134bcda9f1eSBen Dooks 135bcda9f1eSBen Dooks iounmap(pd->reg); 13642543aebSAnton Vasilyev release_mem_region(pd->ioarea->start, resource_size(pd->ioarea)); 137bcda9f1eSBen Dooks kfree(pd); 138bcda9f1eSBen Dooks 139bcda9f1eSBen Dooks return 0; 140bcda9f1eSBen Dooks } 141bcda9f1eSBen Dooks 142bcda9f1eSBen Dooks /* device driver */ 143bcda9f1eSBen Dooks 144bcda9f1eSBen Dooks static struct platform_driver simtec_i2c_driver = { 145bcda9f1eSBen Dooks .driver = { 146bcda9f1eSBen Dooks .name = "simtec-i2c", 147bcda9f1eSBen Dooks }, 148bcda9f1eSBen Dooks .probe = simtec_i2c_probe, 149bcda9f1eSBen Dooks .remove = simtec_i2c_remove, 150bcda9f1eSBen Dooks }; 151bcda9f1eSBen Dooks 152a3664b51SAxel Lin module_platform_driver(simtec_i2c_driver); 153bcda9f1eSBen Dooks 154bcda9f1eSBen Dooks MODULE_DESCRIPTION("Simtec Generic I2C Bus driver"); 155bcda9f1eSBen Dooks MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 156bcda9f1eSBen Dooks MODULE_LICENSE("GPL"); 157a3664b51SAxel Lin MODULE_ALIAS("platform:simtec-i2c"); 158