3 * Copyright (C) 2014 IBM
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program.
19 #include <linux/device.h>
20 #include <linux/i2c.h>
21 #include <linux/kernel.h>
23 #include <linux/module.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
28 #include <asm/firmware.h>
31 static int i2c_opal_translate_error(int rc)
38 case OPAL_I2C_ARBT_LOST:
40 case OPAL_I2C_TIMEOUT:
42 case OPAL_I2C_NACK_RCVD:
44 case OPAL_I2C_STOP_ERR:
51 static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
56 token = opal_async_get_token_interruptible();
58 if (token != -ERESTARTSYS)
59 pr_err("Failed to get the async token\n");
64 rc = opal_i2c_request(token, bus_id, req);
65 if (rc != OPAL_ASYNC_COMPLETION) {
66 rc = i2c_opal_translate_error(rc);
70 rc = opal_async_wait_response(token, &msg);
74 rc = be64_to_cpu(msg.params[1]);
75 if (rc != OPAL_SUCCESS) {
76 rc = i2c_opal_translate_error(rc);
81 opal_async_release_token(token);
85 static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
88 unsigned long opal_id = (unsigned long)adap->algo_data;
89 struct opal_i2c_request req;
92 /* We only support fairly simple combinations here of one
95 memset(&req, 0, sizeof(req));
100 req.type = (msgs[0].flags & I2C_M_RD) ?
101 OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
102 req.addr = cpu_to_be16(msgs[0].addr);
103 req.size = cpu_to_be32(msgs[0].len);
104 req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
107 req.type = OPAL_I2C_SM_READ;
108 req.addr = cpu_to_be16(msgs[0].addr);
109 req.subaddr_sz = msgs[0].len;
110 for (i = 0; i < msgs[0].len; i++)
111 req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
112 req.subaddr = cpu_to_be32(req.subaddr);
113 req.size = cpu_to_be32(msgs[1].len);
114 req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
120 rc = i2c_opal_send_request(opal_id, &req);
127 static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
128 unsigned short flags, char read_write,
129 u8 command, int size, union i2c_smbus_data *data)
131 unsigned long opal_id = (unsigned long)adap->algo_data;
132 struct opal_i2c_request req;
136 memset(&req, 0, sizeof(req));
138 req.addr = cpu_to_be16(addr);
141 req.buffer_ra = cpu_to_be64(__pa(&data->byte));
142 req.size = cpu_to_be32(1);
144 case I2C_SMBUS_QUICK:
145 req.type = (read_write == I2C_SMBUS_READ) ?
146 OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
148 case I2C_SMBUS_BYTE_DATA:
149 req.buffer_ra = cpu_to_be64(__pa(&data->byte));
150 req.size = cpu_to_be32(1);
151 req.subaddr = cpu_to_be32(command);
153 req.type = (read_write == I2C_SMBUS_READ) ?
154 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
156 case I2C_SMBUS_WORD_DATA:
158 local[0] = data->word & 0xff;
159 local[1] = (data->word >> 8) & 0xff;
161 req.buffer_ra = cpu_to_be64(__pa(local));
162 req.size = cpu_to_be32(2);
163 req.subaddr = cpu_to_be32(command);
165 req.type = (read_write == I2C_SMBUS_READ) ?
166 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
168 case I2C_SMBUS_I2C_BLOCK_DATA:
169 req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
170 req.size = cpu_to_be32(data->block[0]);
171 req.subaddr = cpu_to_be32(command);
173 req.type = (read_write == I2C_SMBUS_READ) ?
174 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
180 rc = i2c_opal_send_request(opal_id, &req);
181 if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
182 data->word = ((u16)local[1]) << 8;
183 data->word |= local[0];
189 static u32 i2c_opal_func(struct i2c_adapter *adapter)
191 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
192 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
193 I2C_FUNC_SMBUS_I2C_BLOCK;
196 static const struct i2c_algorithm i2c_opal_algo = {
197 .master_xfer = i2c_opal_master_xfer,
198 .smbus_xfer = i2c_opal_smbus_xfer,
199 .functionality = i2c_opal_func,
202 /* For two messages, we basically support only simple
203 * smbus transactions of a write plus a read. We might
204 * want to allow also two writes but we'd have to bounce
205 * the data into a single buffer.
207 static struct i2c_adapter_quirks i2c_opal_quirks = {
208 .flags = I2C_AQ_COMB_WRITE_THEN_READ,
209 .max_comb_1st_msg_len = 4,
212 static int i2c_opal_probe(struct platform_device *pdev)
214 struct i2c_adapter *adapter;
219 if (!pdev->dev.of_node)
222 rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
224 dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
228 adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
232 adapter->algo = &i2c_opal_algo;
233 adapter->algo_data = (void *)(unsigned long)opal_id;
234 adapter->quirks = &i2c_opal_quirks;
235 adapter->dev.parent = &pdev->dev;
236 adapter->dev.of_node = of_node_get(pdev->dev.of_node);
237 pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
239 strlcpy(adapter->name, pname, sizeof(adapter->name));
241 strlcpy(adapter->name, "opal", sizeof(adapter->name));
243 platform_set_drvdata(pdev, adapter);
244 rc = i2c_add_adapter(adapter);
246 dev_err(&pdev->dev, "Failed to register the i2c adapter\n");
251 static int i2c_opal_remove(struct platform_device *pdev)
253 struct i2c_adapter *adapter = platform_get_drvdata(pdev);
255 i2c_del_adapter(adapter);
260 static const struct of_device_id i2c_opal_of_match[] = {
262 .compatible = "ibm,opal-i2c",
266 MODULE_DEVICE_TABLE(of, i2c_opal_of_match);
268 static struct platform_driver i2c_opal_driver = {
269 .probe = i2c_opal_probe,
270 .remove = i2c_opal_remove,
273 .of_match_table = i2c_opal_of_match,
277 static int __init i2c_opal_init(void)
279 if (!firmware_has_feature(FW_FEATURE_OPAL))
282 return platform_driver_register(&i2c_opal_driver);
284 module_init(i2c_opal_init);
286 static void __exit i2c_opal_exit(void)
288 return platform_driver_unregister(&i2c_opal_driver);
290 module_exit(i2c_opal_exit);
292 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
293 MODULE_DESCRIPTION("IBM OPAL I2C driver");
294 MODULE_LICENSE("GPL");