Loading...
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 | /*
* IBM OPAL I2C driver
* Copyright (C) 2014 IBM
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*/
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/firmware.h>
#include <asm/opal.h>
static int i2c_opal_translate_error(int rc)
{
switch (rc) {
case OPAL_NO_MEM:
return -ENOMEM;
case OPAL_PARAMETER:
return -EINVAL;
case OPAL_I2C_ARBT_LOST:
return -EAGAIN;
case OPAL_I2C_TIMEOUT:
return -ETIMEDOUT;
case OPAL_I2C_NACK_RCVD:
return -ENXIO;
case OPAL_I2C_STOP_ERR:
return -EBUSY;
default:
return -EIO;
}
}
static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
{
struct opal_msg msg;
int token, rc;
token = opal_async_get_token_interruptible();
if (token < 0) {
if (token != -ERESTARTSYS)
pr_err("Failed to get the async token\n");
return token;
}
rc = opal_i2c_request(token, bus_id, req);
if (rc != OPAL_ASYNC_COMPLETION) {
rc = i2c_opal_translate_error(rc);
goto exit;
}
rc = opal_async_wait_response(token, &msg);
if (rc)
goto exit;
rc = opal_get_async_rc(msg);
if (rc != OPAL_SUCCESS) {
rc = i2c_opal_translate_error(rc);
goto exit;
}
exit:
opal_async_release_token(token);
return rc;
}
static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num)
{
unsigned long opal_id = (unsigned long)adap->algo_data;
struct opal_i2c_request req;
int rc, i;
/* We only support fairly simple combinations here of one
* or two messages
*/
memset(&req, 0, sizeof(req));
switch(num) {
case 0:
return 0;
case 1:
req.type = (msgs[0].flags & I2C_M_RD) ?
OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
req.addr = cpu_to_be16(msgs[0].addr);
req.size = cpu_to_be32(msgs[0].len);
req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
break;
case 2:
req.type = (msgs[1].flags & I2C_M_RD) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
req.addr = cpu_to_be16(msgs[0].addr);
req.subaddr_sz = msgs[0].len;
for (i = 0; i < msgs[0].len; i++)
req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
req.subaddr = cpu_to_be32(req.subaddr);
req.size = cpu_to_be32(msgs[1].len);
req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
break;
default:
return -EOPNOTSUPP;
}
rc = i2c_opal_send_request(opal_id, &req);
if (rc)
return rc;
return num;
}
static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data *data)
{
unsigned long opal_id = (unsigned long)adap->algo_data;
struct opal_i2c_request req;
u8 local[2];
int rc;
memset(&req, 0, sizeof(req));
req.addr = cpu_to_be16(addr);
switch (size) {
case I2C_SMBUS_BYTE:
req.buffer_ra = cpu_to_be64(__pa(&data->byte));
req.size = cpu_to_be32(1);
/* Fall through */
case I2C_SMBUS_QUICK:
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
break;
case I2C_SMBUS_BYTE_DATA:
req.buffer_ra = cpu_to_be64(__pa(&data->byte));
req.size = cpu_to_be32(1);
req.subaddr = cpu_to_be32(command);
req.subaddr_sz = 1;
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
break;
case I2C_SMBUS_WORD_DATA:
if (!read_write) {
local[0] = data->word & 0xff;
local[1] = (data->word >> 8) & 0xff;
}
req.buffer_ra = cpu_to_be64(__pa(local));
req.size = cpu_to_be32(2);
req.subaddr = cpu_to_be32(command);
req.subaddr_sz = 1;
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
req.size = cpu_to_be32(data->block[0]);
req.subaddr = cpu_to_be32(command);
req.subaddr_sz = 1;
req.type = (read_write == I2C_SMBUS_READ) ?
OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
break;
default:
return -EINVAL;
}
rc = i2c_opal_send_request(opal_id, &req);
if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
data->word = ((u16)local[1]) << 8;
data->word |= local[0];
}
return rc;
}
static u32 i2c_opal_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;
}
static const struct i2c_algorithm i2c_opal_algo = {
.master_xfer = i2c_opal_master_xfer,
.smbus_xfer = i2c_opal_smbus_xfer,
.functionality = i2c_opal_func,
};
/*
* For two messages, we basically support simple smbus transactions of a
* write-then-anything.
*/
static struct i2c_adapter_quirks i2c_opal_quirks = {
.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
.max_comb_1st_msg_len = 4,
};
static int i2c_opal_probe(struct platform_device *pdev)
{
struct i2c_adapter *adapter;
const char *pname;
u32 opal_id;
int rc;
if (!pdev->dev.of_node)
return -ENODEV;
rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
if (rc) {
dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
return -EIO;
}
adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
if (!adapter)
return -ENOMEM;
adapter->algo = &i2c_opal_algo;
adapter->algo_data = (void *)(unsigned long)opal_id;
adapter->quirks = &i2c_opal_quirks;
adapter->dev.parent = &pdev->dev;
adapter->dev.of_node = of_node_get(pdev->dev.of_node);
pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
if (pname)
strlcpy(adapter->name, pname, sizeof(adapter->name));
else
strlcpy(adapter->name, "opal", sizeof(adapter->name));
platform_set_drvdata(pdev, adapter);
rc = i2c_add_adapter(adapter);
if (rc)
dev_err(&pdev->dev, "Failed to register the i2c adapter\n");
return rc;
}
static int i2c_opal_remove(struct platform_device *pdev)
{
struct i2c_adapter *adapter = platform_get_drvdata(pdev);
i2c_del_adapter(adapter);
return 0;
}
static const struct of_device_id i2c_opal_of_match[] = {
{
.compatible = "ibm,opal-i2c",
},
{ }
};
MODULE_DEVICE_TABLE(of, i2c_opal_of_match);
static struct platform_driver i2c_opal_driver = {
.probe = i2c_opal_probe,
.remove = i2c_opal_remove,
.driver = {
.name = "i2c-opal",
.of_match_table = i2c_opal_of_match,
},
};
static int __init i2c_opal_init(void)
{
if (!firmware_has_feature(FW_FEATURE_OPAL))
return -ENODEV;
return platform_driver_register(&i2c_opal_driver);
}
module_init(i2c_opal_init);
static void __exit i2c_opal_exit(void)
{
return platform_driver_unregister(&i2c_opal_driver);
}
module_exit(i2c_opal_exit);
MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("IBM OPAL I2C driver");
MODULE_LICENSE("GPL");
|