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10#include <linux/err.h>
11#include <linux/i2c.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/of_device.h>
16#include <linux/platform_device.h>
17#include <linux/pm_runtime.h>
18
19#include <soc/tegra/bpmp-abi.h>
20#include <soc/tegra/bpmp.h>
21
22
23
24
25
26#define SERIALI2C_HDR_SIZE 6
27
28struct tegra_bpmp_i2c {
29 struct i2c_adapter adapter;
30 struct device *dev;
31
32 struct tegra_bpmp *bpmp;
33 unsigned int bus;
34};
35
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38
39
40
41static int tegra_bpmp_xlate_flags(u16 flags, u16 *out)
42{
43 if (flags & I2C_M_TEN) {
44 *out |= SERIALI2C_TEN;
45 flags &= ~I2C_M_TEN;
46 }
47
48 if (flags & I2C_M_RD) {
49 *out |= SERIALI2C_RD;
50 flags &= ~I2C_M_RD;
51 }
52
53 if (flags & I2C_M_STOP) {
54 *out |= SERIALI2C_STOP;
55 flags &= ~I2C_M_STOP;
56 }
57
58 if (flags & I2C_M_NOSTART) {
59 *out |= SERIALI2C_NOSTART;
60 flags &= ~I2C_M_NOSTART;
61 }
62
63 if (flags & I2C_M_REV_DIR_ADDR) {
64 *out |= SERIALI2C_REV_DIR_ADDR;
65 flags &= ~I2C_M_REV_DIR_ADDR;
66 }
67
68 if (flags & I2C_M_IGNORE_NAK) {
69 *out |= SERIALI2C_IGNORE_NAK;
70 flags &= ~I2C_M_IGNORE_NAK;
71 }
72
73 if (flags & I2C_M_NO_RD_ACK) {
74 *out |= SERIALI2C_NO_RD_ACK;
75 flags &= ~I2C_M_NO_RD_ACK;
76 }
77
78 if (flags & I2C_M_RECV_LEN) {
79 *out |= SERIALI2C_RECV_LEN;
80 flags &= ~I2C_M_RECV_LEN;
81 }
82
83 return (flags != 0) ? -EINVAL : 0;
84}
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99
100static int tegra_bpmp_serialize_i2c_msg(struct tegra_bpmp_i2c *i2c,
101 struct mrq_i2c_request *request,
102 struct i2c_msg *msgs,
103 unsigned int num)
104{
105 char *buf = request->xfer.data_buf;
106 unsigned int i, j, pos = 0;
107 int err;
108
109 for (i = 0; i < num; i++) {
110 struct i2c_msg *msg = &msgs[i];
111 u16 flags = 0;
112
113 err = tegra_bpmp_xlate_flags(msg->flags, &flags);
114 if (err < 0)
115 return err;
116
117 buf[pos++] = msg->addr & 0xff;
118 buf[pos++] = (msg->addr & 0xff00) >> 8;
119 buf[pos++] = flags & 0xff;
120 buf[pos++] = (flags & 0xff00) >> 8;
121 buf[pos++] = msg->len & 0xff;
122 buf[pos++] = (msg->len & 0xff00) >> 8;
123
124 if ((flags & SERIALI2C_RD) == 0) {
125 for (j = 0; j < msg->len; j++)
126 buf[pos++] = msg->buf[j];
127 }
128 }
129
130 request->xfer.data_size = pos;
131
132 return 0;
133}
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148
149static int tegra_bpmp_i2c_deserialize(struct tegra_bpmp_i2c *i2c,
150 struct mrq_i2c_response *response,
151 struct i2c_msg *msgs,
152 unsigned int num)
153{
154 size_t size = response->xfer.data_size, len = 0, pos = 0;
155 char *buf = response->xfer.data_buf;
156 unsigned int i;
157
158 for (i = 0; i < num; i++)
159 if (msgs[i].flags & I2C_M_RD)
160 len += msgs[i].len;
161
162 if (len != size)
163 return -EINVAL;
164
165 for (i = 0; i < num; i++) {
166 if (msgs[i].flags & I2C_M_RD) {
167 memcpy(msgs[i].buf, buf + pos, msgs[i].len);
168 pos += msgs[i].len;
169 }
170 }
171
172 return 0;
173}
174
175static int tegra_bpmp_i2c_msg_len_check(struct i2c_msg *msgs, unsigned int num)
176{
177 size_t tx_len = 0, rx_len = 0;
178 unsigned int i;
179
180 for (i = 0; i < num; i++)
181 if (!(msgs[i].flags & I2C_M_RD))
182 tx_len += SERIALI2C_HDR_SIZE + msgs[i].len;
183
184 if (tx_len > TEGRA_I2C_IPC_MAX_IN_BUF_SIZE)
185 return -EINVAL;
186
187 for (i = 0; i < num; i++)
188 if ((msgs[i].flags & I2C_M_RD))
189 rx_len += msgs[i].len;
190
191 if (rx_len > TEGRA_I2C_IPC_MAX_OUT_BUF_SIZE)
192 return -EINVAL;
193
194 return 0;
195}
196
197static int tegra_bpmp_i2c_msg_xfer(struct tegra_bpmp_i2c *i2c,
198 struct mrq_i2c_request *request,
199 struct mrq_i2c_response *response,
200 bool atomic)
201{
202 struct tegra_bpmp_message msg;
203 int err;
204
205 request->cmd = CMD_I2C_XFER;
206 request->xfer.bus_id = i2c->bus;
207
208 memset(&msg, 0, sizeof(msg));
209 msg.mrq = MRQ_I2C;
210 msg.tx.data = request;
211 msg.tx.size = sizeof(*request);
212 msg.rx.data = response;
213 msg.rx.size = sizeof(*response);
214
215 if (atomic)
216 err = tegra_bpmp_transfer_atomic(i2c->bpmp, &msg);
217 else
218 err = tegra_bpmp_transfer(i2c->bpmp, &msg);
219
220 return err;
221}
222
223static int tegra_bpmp_i2c_xfer_common(struct i2c_adapter *adapter,
224 struct i2c_msg *msgs, int num,
225 bool atomic)
226{
227 struct tegra_bpmp_i2c *i2c = i2c_get_adapdata(adapter);
228 struct mrq_i2c_response response;
229 struct mrq_i2c_request request;
230 int err;
231
232 err = tegra_bpmp_i2c_msg_len_check(msgs, num);
233 if (err < 0) {
234 dev_err(i2c->dev, "unsupported message length\n");
235 return err;
236 }
237
238 memset(&request, 0, sizeof(request));
239 memset(&response, 0, sizeof(response));
240
241 err = tegra_bpmp_serialize_i2c_msg(i2c, &request, msgs, num);
242 if (err < 0) {
243 dev_err(i2c->dev, "failed to serialize message: %d\n", err);
244 return err;
245 }
246
247 err = tegra_bpmp_i2c_msg_xfer(i2c, &request, &response, atomic);
248 if (err < 0) {
249 dev_err(i2c->dev, "failed to transfer message: %d\n", err);
250 return err;
251 }
252
253 err = tegra_bpmp_i2c_deserialize(i2c, &response, msgs, num);
254 if (err < 0) {
255 dev_err(i2c->dev, "failed to deserialize message: %d\n", err);
256 return err;
257 }
258
259 return num;
260}
261
262static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter,
263 struct i2c_msg *msgs, int num)
264{
265 return tegra_bpmp_i2c_xfer_common(adapter, msgs, num, false);
266}
267
268static int tegra_bpmp_i2c_xfer_atomic(struct i2c_adapter *adapter,
269 struct i2c_msg *msgs, int num)
270{
271 return tegra_bpmp_i2c_xfer_common(adapter, msgs, num, true);
272}
273
274static u32 tegra_bpmp_i2c_func(struct i2c_adapter *adapter)
275{
276 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
277 I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
278}
279
280static const struct i2c_algorithm tegra_bpmp_i2c_algo = {
281 .master_xfer = tegra_bpmp_i2c_xfer,
282 .master_xfer_atomic = tegra_bpmp_i2c_xfer_atomic,
283 .functionality = tegra_bpmp_i2c_func,
284};
285
286static int tegra_bpmp_i2c_probe(struct platform_device *pdev)
287{
288 struct tegra_bpmp_i2c *i2c;
289 u32 value;
290 int err;
291
292 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
293 if (!i2c)
294 return -ENOMEM;
295
296 i2c->dev = &pdev->dev;
297
298 i2c->bpmp = dev_get_drvdata(pdev->dev.parent);
299 if (!i2c->bpmp)
300 return -ENODEV;
301
302 err = of_property_read_u32(pdev->dev.of_node, "nvidia,bpmp-bus-id",
303 &value);
304 if (err < 0)
305 return err;
306
307 i2c->bus = value;
308
309 i2c_set_adapdata(&i2c->adapter, i2c);
310 i2c->adapter.owner = THIS_MODULE;
311 strlcpy(i2c->adapter.name, "Tegra BPMP I2C adapter",
312 sizeof(i2c->adapter.name));
313 i2c->adapter.algo = &tegra_bpmp_i2c_algo;
314 i2c->adapter.dev.parent = &pdev->dev;
315 i2c->adapter.dev.of_node = pdev->dev.of_node;
316
317 platform_set_drvdata(pdev, i2c);
318
319 return i2c_add_adapter(&i2c->adapter);
320}
321
322static int tegra_bpmp_i2c_remove(struct platform_device *pdev)
323{
324 struct tegra_bpmp_i2c *i2c = platform_get_drvdata(pdev);
325
326 i2c_del_adapter(&i2c->adapter);
327
328 return 0;
329}
330
331static const struct of_device_id tegra_bpmp_i2c_of_match[] = {
332 { .compatible = "nvidia,tegra186-bpmp-i2c", },
333 { }
334};
335MODULE_DEVICE_TABLE(of, tegra_bpmp_i2c_of_match);
336
337static struct platform_driver tegra_bpmp_i2c_driver = {
338 .driver = {
339 .name = "tegra-bpmp-i2c",
340 .of_match_table = tegra_bpmp_i2c_of_match,
341 },
342 .probe = tegra_bpmp_i2c_probe,
343 .remove = tegra_bpmp_i2c_remove,
344};
345module_platform_driver(tegra_bpmp_i2c_driver);
346
347MODULE_DESCRIPTION("NVIDIA Tegra BPMP I2C bus controller driver");
348MODULE_AUTHOR("Shardar Shariff Md <smohammed@nvidia.com>");
349MODULE_AUTHOR("Juha-Matti Tilli");
350MODULE_LICENSE("GPL v2");
351
