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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 | // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2005 Simtec Electronics * Ben Dooks <ben@simtec.co.uk> * * Simtec Generic I2C Controller */ #include <linux/kernel.h> #include <linux/module.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) 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; strscpy(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_mem_region(pd->ioarea->start, size); 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_mem_region(pd->ioarea->start, resource_size(pd->ioarea)); kfree(pd); return 0; } /* device driver */ static struct platform_driver simtec_i2c_driver = { .driver = { .name = "simtec-i2c", }, .probe = simtec_i2c_probe, .remove = simtec_i2c_remove, }; module_platform_driver(simtec_i2c_driver); MODULE_DESCRIPTION("Simtec Generic I2C Bus driver"); MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:simtec-i2c"); |