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12#include <linux/acpi.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/slab.h>
17#include <linux/types.h>
18
19#include "i2c-amd-mp2.h"
20
21#define AMD_MP2_I2C_MAX_RW_LENGTH ((1 << 12) - 1)
22#define AMD_I2C_TIMEOUT (msecs_to_jiffies(250))
23
24
25
26
27
28
29
30
31struct amd_i2c_dev {
32 struct amd_i2c_common common;
33 struct platform_device *pdev;
34 struct i2c_adapter adap;
35 struct completion cmd_complete;
36};
37
38#define amd_i2c_dev_common(__common) \
39 container_of(__common, struct amd_i2c_dev, common)
40
41static int i2c_amd_dma_map(struct amd_i2c_common *i2c_common)
42{
43 struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
44 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
45 enum dma_data_direction dma_direction =
46 i2c_common->msg->flags & I2C_M_RD ?
47 DMA_FROM_DEVICE : DMA_TO_DEVICE;
48
49 i2c_common->dma_buf = i2c_get_dma_safe_msg_buf(i2c_common->msg, 0);
50 i2c_common->dma_addr = dma_map_single(dev_pci, i2c_common->dma_buf,
51 i2c_common->msg->len,
52 dma_direction);
53
54 if (unlikely(dma_mapping_error(dev_pci, i2c_common->dma_addr))) {
55 dev_err(&i2c_dev->pdev->dev,
56 "Error while mapping dma buffer %p\n",
57 i2c_common->dma_buf);
58 return -EIO;
59 }
60
61 return 0;
62}
63
64static void i2c_amd_dma_unmap(struct amd_i2c_common *i2c_common)
65{
66 struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
67 enum dma_data_direction dma_direction =
68 i2c_common->msg->flags & I2C_M_RD ?
69 DMA_FROM_DEVICE : DMA_TO_DEVICE;
70
71 dma_unmap_single(dev_pci, i2c_common->dma_addr,
72 i2c_common->msg->len, dma_direction);
73
74 i2c_put_dma_safe_msg_buf(i2c_common->dma_buf, i2c_common->msg, true);
75}
76
77static void i2c_amd_start_cmd(struct amd_i2c_dev *i2c_dev)
78{
79 struct amd_i2c_common *i2c_common = &i2c_dev->common;
80
81 reinit_completion(&i2c_dev->cmd_complete);
82 i2c_common->cmd_success = false;
83}
84
85static void i2c_amd_cmd_completion(struct amd_i2c_common *i2c_common)
86{
87 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
88 union i2c_event *event = &i2c_common->eventval;
89
90 if (event->r.status == i2c_readcomplete_event)
91 dev_dbg(&i2c_dev->pdev->dev, "%s readdata:%*ph\n",
92 __func__, event->r.length,
93 i2c_common->msg->buf);
94
95 complete(&i2c_dev->cmd_complete);
96}
97
98static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev)
99{
100 struct amd_i2c_common *i2c_common = &i2c_dev->common;
101 unsigned long timeout;
102
103 timeout = wait_for_completion_timeout(&i2c_dev->cmd_complete,
104 i2c_dev->adap.timeout);
105
106 if ((i2c_common->reqcmd == i2c_read ||
107 i2c_common->reqcmd == i2c_write) &&
108 i2c_common->msg->len > 32)
109 i2c_amd_dma_unmap(i2c_common);
110
111 if (timeout == 0) {
112 amd_mp2_rw_timeout(i2c_common);
113 return -ETIMEDOUT;
114 }
115
116 amd_mp2_process_event(i2c_common);
117
118 if (!i2c_common->cmd_success)
119 return -EIO;
120
121 return 0;
122}
123
124static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable)
125{
126 struct amd_i2c_common *i2c_common = &i2c_dev->common;
127
128 i2c_amd_start_cmd(i2c_dev);
129 amd_mp2_bus_enable_set(i2c_common, enable);
130
131 return i2c_amd_check_cmd_completion(i2c_dev);
132}
133
134static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg)
135{
136 struct amd_i2c_common *i2c_common = &i2c_dev->common;
137
138 i2c_amd_start_cmd(i2c_dev);
139 i2c_common->msg = pmsg;
140
141 if (pmsg->len > 32)
142 if (i2c_amd_dma_map(i2c_common))
143 return -EIO;
144
145 if (pmsg->flags & I2C_M_RD)
146 amd_mp2_rw(i2c_common, i2c_read);
147 else
148 amd_mp2_rw(i2c_common, i2c_write);
149
150 return i2c_amd_check_cmd_completion(i2c_dev);
151}
152
153static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
154{
155 struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
156 int i;
157 struct i2c_msg *pmsg;
158 int err = 0;
159
160
161 if (unlikely(!i2c_dev->common.mp2_dev))
162 return -EINVAL;
163
164 amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev);
165
166 for (i = 0; i < num; i++) {
167 pmsg = &msgs[i];
168 err = i2c_amd_xfer_msg(i2c_dev, pmsg);
169 if (err)
170 break;
171 }
172
173 amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev);
174 return err ? err : num;
175}
176
177static u32 i2c_amd_func(struct i2c_adapter *a)
178{
179 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
180}
181
182static const struct i2c_algorithm i2c_amd_algorithm = {
183 .master_xfer = i2c_amd_xfer,
184 .functionality = i2c_amd_func,
185};
186
187#ifdef CONFIG_PM
188static int i2c_amd_suspend(struct amd_i2c_common *i2c_common)
189{
190 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
191
192 i2c_amd_enable_set(i2c_dev, false);
193 return 0;
194}
195
196static int i2c_amd_resume(struct amd_i2c_common *i2c_common)
197{
198 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
199
200 return i2c_amd_enable_set(i2c_dev, true);
201}
202#endif
203
204static const u32 supported_speeds[] = {
205 I2C_MAX_HIGH_SPEED_MODE_FREQ,
206 I2C_MAX_TURBO_MODE_FREQ,
207 I2C_MAX_FAST_MODE_PLUS_FREQ,
208 I2C_MAX_FAST_MODE_FREQ,
209 I2C_MAX_STANDARD_MODE_FREQ,
210};
211
212static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev)
213{
214 u32 acpi_speed;
215 int i;
216
217 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
218
219 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {
220 if (acpi_speed >= supported_speeds[i])
221 break;
222 }
223 acpi_speed = i < ARRAY_SIZE(supported_speeds) ? supported_speeds[i] : 0;
224
225 switch (acpi_speed) {
226 case I2C_MAX_STANDARD_MODE_FREQ:
227 return speed100k;
228 case I2C_MAX_FAST_MODE_FREQ:
229 return speed400k;
230 case I2C_MAX_FAST_MODE_PLUS_FREQ:
231 return speed1000k;
232 case I2C_MAX_TURBO_MODE_FREQ:
233 return speed1400k;
234 case I2C_MAX_HIGH_SPEED_MODE_FREQ:
235 return speed3400k;
236 default:
237 return speed400k;
238 }
239}
240
241static const struct i2c_adapter_quirks amd_i2c_dev_quirks = {
242 .max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH,
243 .max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH,
244};
245
246static int i2c_amd_probe(struct platform_device *pdev)
247{
248 int ret;
249 struct amd_i2c_dev *i2c_dev;
250 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
251 struct acpi_device *adev;
252 struct amd_mp2_dev *mp2_dev;
253 const char *uid;
254
255 if (acpi_bus_get_device(handle, &adev))
256 return -ENODEV;
257
258
259
260
261
262 mp2_dev = amd_mp2_find_device();
263 if (!mp2_dev || !mp2_dev->probed)
264
265 return -EPROBE_DEFER;
266
267 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
268 if (!i2c_dev)
269 return -ENOMEM;
270
271 i2c_dev->common.mp2_dev = mp2_dev;
272 i2c_dev->pdev = pdev;
273 platform_set_drvdata(pdev, i2c_dev);
274
275 i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion;
276#ifdef CONFIG_PM
277 i2c_dev->common.suspend = &i2c_amd_suspend;
278 i2c_dev->common.resume = &i2c_amd_resume;
279#endif
280
281 uid = adev->pnp.unique_id;
282 if (!uid) {
283 dev_err(&pdev->dev, "missing UID/bus id!\n");
284 return -EINVAL;
285 } else if (strcmp(uid, "0") == 0) {
286 i2c_dev->common.bus_id = 0;
287 } else if (strcmp(uid, "1") == 0) {
288 i2c_dev->common.bus_id = 1;
289 } else {
290 dev_err(&pdev->dev, "incorrect UID/bus id \"%s\"!\n", uid);
291 return -EINVAL;
292 }
293 dev_dbg(&pdev->dev, "bus id is %u\n", i2c_dev->common.bus_id);
294
295
296 amd_mp2_pm_runtime_get(mp2_dev);
297
298 i2c_dev->common.reqcmd = i2c_none;
299 if (amd_mp2_register_cb(&i2c_dev->common))
300 return -EINVAL;
301 device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev,
302 DL_FLAG_AUTOREMOVE_CONSUMER);
303
304 i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev);
305
306
307 i2c_dev->adap.owner = THIS_MODULE;
308 i2c_dev->adap.algo = &i2c_amd_algorithm;
309 i2c_dev->adap.quirks = &amd_i2c_dev_quirks;
310 i2c_dev->adap.dev.parent = &pdev->dev;
311 i2c_dev->adap.algo_data = i2c_dev;
312 i2c_dev->adap.timeout = AMD_I2C_TIMEOUT;
313 ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev));
314 i2c_dev->adap.dev.of_node = pdev->dev.of_node;
315 snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
316 "AMD MP2 i2c bus %u", i2c_dev->common.bus_id);
317 i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
318
319 init_completion(&i2c_dev->cmd_complete);
320
321
322 if (i2c_amd_enable_set(i2c_dev, true))
323 dev_err(&pdev->dev, "initial bus enable failed\n");
324
325
326 ret = i2c_add_adapter(&i2c_dev->adap);
327
328 amd_mp2_pm_runtime_put(mp2_dev);
329
330 if (ret < 0)
331 dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret);
332
333 return ret;
334}
335
336static int i2c_amd_remove(struct platform_device *pdev)
337{
338 struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
339 struct amd_i2c_common *i2c_common = &i2c_dev->common;
340
341 i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
342
343 i2c_amd_enable_set(i2c_dev, false);
344 amd_mp2_unregister_cb(i2c_common);
345 i2c_common->mp2_dev = NULL;
346
347 i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
348
349 i2c_del_adapter(&i2c_dev->adap);
350 return 0;
351}
352
353static const struct acpi_device_id i2c_amd_acpi_match[] = {
354 { "AMDI0011" },
355 { },
356};
357MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match);
358
359static struct platform_driver i2c_amd_plat_driver = {
360 .probe = i2c_amd_probe,
361 .remove = i2c_amd_remove,
362 .driver = {
363 .name = "i2c_amd_mp2",
364 .acpi_match_table = ACPI_PTR(i2c_amd_acpi_match),
365 },
366};
367module_platform_driver(i2c_amd_plat_driver);
368
369MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver");
370MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah@amd.com>");
371MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");
372MODULE_LICENSE("Dual BSD/GPL");
373
