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19#include <linux/device.h>
20#include <linux/i2c.h>
21#include <linux/kernel.h>
22#include <linux/mm.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/platform_device.h>
26#include <linux/slab.h>
27
28#include <asm/firmware.h>
29#include <asm/opal.h>
30
31static int i2c_opal_translate_error(int rc)
32{
33 switch (rc) {
34 case OPAL_NO_MEM:
35 return -ENOMEM;
36 case OPAL_PARAMETER:
37 return -EINVAL;
38 case OPAL_I2C_ARBT_LOST:
39 return -EAGAIN;
40 case OPAL_I2C_TIMEOUT:
41 return -ETIMEDOUT;
42 case OPAL_I2C_NACK_RCVD:
43 return -ENXIO;
44 case OPAL_I2C_STOP_ERR:
45 return -EBUSY;
46 default:
47 return -EIO;
48 }
49}
50
51static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
52{
53 struct opal_msg msg;
54 int token, rc;
55
56 token = opal_async_get_token_interruptible();
57 if (token < 0) {
58 if (token != -ERESTARTSYS)
59 pr_err("Failed to get the async token\n");
60
61 return token;
62 }
63
64 rc = opal_i2c_request(token, bus_id, req);
65 if (rc != OPAL_ASYNC_COMPLETION) {
66 rc = i2c_opal_translate_error(rc);
67 goto exit;
68 }
69
70 rc = opal_async_wait_response(token, &msg);
71 if (rc)
72 goto exit;
73
74 rc = opal_get_async_rc(msg);
75 if (rc != OPAL_SUCCESS) {
76 rc = i2c_opal_translate_error(rc);
77 goto exit;
78 }
79
80exit:
81 opal_async_release_token(token);
82 return rc;
83}
84
85static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
86 int num)
87{
88 unsigned long opal_id = (unsigned long)adap->algo_data;
89 struct opal_i2c_request req;
90 int rc, i;
91
92
93
94
95 memset(&req, 0, sizeof(req));
96 switch(num) {
97 case 0:
98 return 0;
99 case 1:
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));
105 break;
106 case 2:
107 req.type = (msgs[1].flags & I2C_M_RD) ?
108 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
109 req.addr = cpu_to_be16(msgs[0].addr);
110 req.subaddr_sz = msgs[0].len;
111 for (i = 0; i < msgs[0].len; i++)
112 req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
113 req.subaddr = cpu_to_be32(req.subaddr);
114 req.size = cpu_to_be32(msgs[1].len);
115 req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
116 break;
117 default:
118 return -EOPNOTSUPP;
119 }
120
121 rc = i2c_opal_send_request(opal_id, &req);
122 if (rc)
123 return rc;
124
125 return num;
126}
127
128static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
129 unsigned short flags, char read_write,
130 u8 command, int size, union i2c_smbus_data *data)
131{
132 unsigned long opal_id = (unsigned long)adap->algo_data;
133 struct opal_i2c_request req;
134 u8 local[2];
135 int rc;
136
137 memset(&req, 0, sizeof(req));
138
139 req.addr = cpu_to_be16(addr);
140 switch (size) {
141 case I2C_SMBUS_BYTE:
142 req.buffer_ra = cpu_to_be64(__pa(&data->byte));
143 req.size = cpu_to_be32(1);
144
145 case I2C_SMBUS_QUICK:
146 req.type = (read_write == I2C_SMBUS_READ) ?
147 OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
148 break;
149 case I2C_SMBUS_BYTE_DATA:
150 req.buffer_ra = cpu_to_be64(__pa(&data->byte));
151 req.size = cpu_to_be32(1);
152 req.subaddr = cpu_to_be32(command);
153 req.subaddr_sz = 1;
154 req.type = (read_write == I2C_SMBUS_READ) ?
155 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
156 break;
157 case I2C_SMBUS_WORD_DATA:
158 if (!read_write) {
159 local[0] = data->word & 0xff;
160 local[1] = (data->word >> 8) & 0xff;
161 }
162 req.buffer_ra = cpu_to_be64(__pa(local));
163 req.size = cpu_to_be32(2);
164 req.subaddr = cpu_to_be32(command);
165 req.subaddr_sz = 1;
166 req.type = (read_write == I2C_SMBUS_READ) ?
167 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
168 break;
169 case I2C_SMBUS_I2C_BLOCK_DATA:
170 req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
171 req.size = cpu_to_be32(data->block[0]);
172 req.subaddr = cpu_to_be32(command);
173 req.subaddr_sz = 1;
174 req.type = (read_write == I2C_SMBUS_READ) ?
175 OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
176 break;
177 default:
178 return -EINVAL;
179 }
180
181 rc = i2c_opal_send_request(opal_id, &req);
182 if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
183 data->word = ((u16)local[1]) << 8;
184 data->word |= local[0];
185 }
186
187 return rc;
188}
189
190static u32 i2c_opal_func(struct i2c_adapter *adapter)
191{
192 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
193 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
194 I2C_FUNC_SMBUS_I2C_BLOCK;
195}
196
197static const struct i2c_algorithm i2c_opal_algo = {
198 .master_xfer = i2c_opal_master_xfer,
199 .smbus_xfer = i2c_opal_smbus_xfer,
200 .functionality = i2c_opal_func,
201};
202
203
204
205
206
207static struct i2c_adapter_quirks i2c_opal_quirks = {
208 .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
209 .max_comb_1st_msg_len = 4,
210};
211
212static int i2c_opal_probe(struct platform_device *pdev)
213{
214 struct i2c_adapter *adapter;
215 const char *pname;
216 u32 opal_id;
217 int rc;
218
219 if (!pdev->dev.of_node)
220 return -ENODEV;
221
222 rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
223 if (rc) {
224 dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
225 return -EIO;
226 }
227
228 adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
229 if (!adapter)
230 return -ENOMEM;
231
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);
238 if (pname)
239 strlcpy(adapter->name, pname, sizeof(adapter->name));
240 else
241 strlcpy(adapter->name, "opal", sizeof(adapter->name));
242
243 platform_set_drvdata(pdev, adapter);
244 rc = i2c_add_adapter(adapter);
245 if (rc)
246 dev_err(&pdev->dev, "Failed to register the i2c adapter\n");
247
248 return rc;
249}
250
251static int i2c_opal_remove(struct platform_device *pdev)
252{
253 struct i2c_adapter *adapter = platform_get_drvdata(pdev);
254
255 i2c_del_adapter(adapter);
256
257 return 0;
258}
259
260static const struct of_device_id i2c_opal_of_match[] = {
261 {
262 .compatible = "ibm,opal-i2c",
263 },
264 { }
265};
266MODULE_DEVICE_TABLE(of, i2c_opal_of_match);
267
268static struct platform_driver i2c_opal_driver = {
269 .probe = i2c_opal_probe,
270 .remove = i2c_opal_remove,
271 .driver = {
272 .name = "i2c-opal",
273 .of_match_table = i2c_opal_of_match,
274 },
275};
276
277static int __init i2c_opal_init(void)
278{
279 if (!firmware_has_feature(FW_FEATURE_OPAL))
280 return -ENODEV;
281
282 return platform_driver_register(&i2c_opal_driver);
283}
284module_init(i2c_opal_init);
285
286static void __exit i2c_opal_exit(void)
287{
288 return platform_driver_unregister(&i2c_opal_driver);
289}
290module_exit(i2c_opal_exit);
291
292MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
293MODULE_DESCRIPTION("IBM OPAL I2C driver");
294MODULE_LICENSE("GPL");
295
