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47083450 NG |
1 | /* |
2 | * IBM OPAL I2C driver | |
3 | * Copyright (C) 2014 IBM | |
4 | * | |
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. | |
9 | * | |
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. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. | |
17 | */ | |
18 | ||
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 | ||
31 | static 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 | ||
51 | static 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 = be64_to_cpu(msg.params[1]); | |
75 | if (rc != OPAL_SUCCESS) { | |
76 | rc = i2c_opal_translate_error(rc); | |
77 | goto exit; | |
78 | } | |
79 | ||
80 | exit: | |
81 | opal_async_release_token(token); | |
82 | return rc; | |
83 | } | |
84 | ||
85 | static 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 | /* We only support fairly simple combinations here of one | |
93 | * or two messages | |
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: | |
bf070380 NG |
107 | req.type = (msgs[1].flags & I2C_M_RD) ? |
108 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; | |
47083450 NG |
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 | ||
128 | static 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 | /* Fall through */ | |
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 | ||
190 | static 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 | ||
197 | static 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 | ||
bf070380 NG |
203 | /* |
204 | * For two messages, we basically support simple smbus transactions of a | |
205 | * write-then-anything. | |
a531afdf WS |
206 | */ |
207 | static struct i2c_adapter_quirks i2c_opal_quirks = { | |
bf070380 | 208 | .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR, |
a531afdf WS |
209 | .max_comb_1st_msg_len = 4, |
210 | }; | |
211 | ||
47083450 NG |
212 | static 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; | |
a531afdf | 234 | adapter->quirks = &i2c_opal_quirks; |
47083450 NG |
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 | ||
251 | static 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 | ||
260 | static const struct of_device_id i2c_opal_of_match[] = { | |
261 | { | |
262 | .compatible = "ibm,opal-i2c", | |
263 | }, | |
264 | { } | |
265 | }; | |
266 | MODULE_DEVICE_TABLE(of, i2c_opal_of_match); | |
267 | ||
268 | static 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 | ||
277 | static 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 | } | |
284 | module_init(i2c_opal_init); | |
285 | ||
286 | static void __exit i2c_opal_exit(void) | |
287 | { | |
288 | return platform_driver_unregister(&i2c_opal_driver); | |
289 | } | |
290 | module_exit(i2c_opal_exit); | |
291 | ||
292 | MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); | |
293 | MODULE_DESCRIPTION("IBM OPAL I2C driver"); | |
294 | MODULE_LICENSE("GPL"); |