xref: /openbmc/linux/drivers/i2c/busses/i2c-mlxcpld.c (revision 2ed4fa9c)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*
3  * Mellanox i2c driver
4  *
5  * Copyright (C) 2016-2020 Mellanox Technologies
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/i2c.h>
10 #include <linux/init.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/platform_data/mlxreg.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 
18 /* General defines */
19 #define MLXPLAT_CPLD_LPC_I2C_BASE_ADDR	0x2000
20 #define MLXCPLD_I2C_DEVICE_NAME		"i2c_mlxcpld"
21 #define MLXCPLD_I2C_VALID_FLAG		(I2C_M_RECV_LEN | I2C_M_RD)
22 #define MLXCPLD_I2C_BUS_NUM		1
23 #define MLXCPLD_I2C_DATA_REG_SZ		36
24 #define MLXCPLD_I2C_DATA_SZ_BIT		BIT(5)
25 #define MLXCPLD_I2C_DATA_EXT2_SZ_BIT	BIT(6)
26 #define MLXCPLD_I2C_DATA_SZ_MASK	GENMASK(6, 5)
27 #define MLXCPLD_I2C_SMBUS_BLK_BIT	BIT(7)
28 #define MLXCPLD_I2C_MAX_ADDR_LEN	4
29 #define MLXCPLD_I2C_RETR_NUM		2
30 #define MLXCPLD_I2C_XFER_TO		500000 /* usec */
31 #define MLXCPLD_I2C_POLL_TIME		200   /* usec */
32 
33 /* LPC I2C registers */
34 #define MLXCPLD_LPCI2C_CPBLTY_REG	0x0
35 #define MLXCPLD_LPCI2C_CTRL_REG		0x1
36 #define MLXCPLD_LPCI2C_HALF_CYC_REG	0x4
37 #define MLXCPLD_LPCI2C_I2C_HOLD_REG	0x5
38 #define MLXCPLD_LPCI2C_CMD_REG		0x6
39 #define MLXCPLD_LPCI2C_NUM_DAT_REG	0x7
40 #define MLXCPLD_LPCI2C_NUM_ADDR_REG	0x8
41 #define MLXCPLD_LPCI2C_STATUS_REG	0x9
42 #define MLXCPLD_LPCI2C_DATA_REG		0xa
43 
44 /* LPC I2C masks and parameters */
45 #define MLXCPLD_LPCI2C_RST_SEL_MASK	0x1
46 #define MLXCPLD_LPCI2C_TRANS_END	0x1
47 #define MLXCPLD_LPCI2C_STATUS_NACK	0x10
48 #define MLXCPLD_LPCI2C_NO_IND		0
49 #define MLXCPLD_LPCI2C_ACK_IND		1
50 #define MLXCPLD_LPCI2C_NACK_IND		2
51 
52 #define MLXCPLD_I2C_FREQ_1000KHZ_SET	0x04
53 #define MLXCPLD_I2C_FREQ_400KHZ_SET	0x0e
54 #define MLXCPLD_I2C_FREQ_100KHZ_SET	0x42
55 
56 enum mlxcpld_i2c_frequency {
57 	MLXCPLD_I2C_FREQ_1000KHZ = 1,
58 	MLXCPLD_I2C_FREQ_400KHZ = 2,
59 	MLXCPLD_I2C_FREQ_100KHZ = 3,
60 };
61 
62 struct  mlxcpld_i2c_curr_xfer {
63 	u8 cmd;
64 	u8 addr_width;
65 	u8 data_len;
66 	u8 msg_num;
67 	struct i2c_msg *msg;
68 };
69 
70 struct mlxcpld_i2c_priv {
71 	struct i2c_adapter adap;
72 	u32 base_addr;
73 	struct mutex lock;
74 	struct  mlxcpld_i2c_curr_xfer xfer;
75 	struct device *dev;
76 	bool smbus_block;
77 	int polling_time;
78 };
79 
mlxcpld_i2c_lpc_write_buf(u8 * data,u8 len,u32 addr)80 static void mlxcpld_i2c_lpc_write_buf(u8 *data, u8 len, u32 addr)
81 {
82 	int i;
83 
84 	for (i = 0; i < len - len % 4; i += 4)
85 		outl(*(u32 *)(data + i), addr + i);
86 	for (; i < len; ++i)
87 		outb(*(data + i), addr + i);
88 }
89 
mlxcpld_i2c_lpc_read_buf(u8 * data,u8 len,u32 addr)90 static void mlxcpld_i2c_lpc_read_buf(u8 *data, u8 len, u32 addr)
91 {
92 	int i;
93 
94 	for (i = 0; i < len - len % 4; i += 4)
95 		*(u32 *)(data + i) = inl(addr + i);
96 	for (; i < len; ++i)
97 		*(data + i) = inb(addr + i);
98 }
99 
mlxcpld_i2c_read_comm(struct mlxcpld_i2c_priv * priv,u8 offs,u8 * data,u8 datalen)100 static void mlxcpld_i2c_read_comm(struct mlxcpld_i2c_priv *priv, u8 offs,
101 				  u8 *data, u8 datalen)
102 {
103 	u32 addr = priv->base_addr + offs;
104 
105 	switch (datalen) {
106 	case 1:
107 		*(data) = inb(addr);
108 		break;
109 	case 2:
110 		*((u16 *)data) = inw(addr);
111 		break;
112 	case 3:
113 		*((u16 *)data) = inw(addr);
114 		*(data + 2) = inb(addr + 2);
115 		break;
116 	case 4:
117 		*((u32 *)data) = inl(addr);
118 		break;
119 	default:
120 		mlxcpld_i2c_lpc_read_buf(data, datalen, addr);
121 		break;
122 	}
123 }
124 
mlxcpld_i2c_write_comm(struct mlxcpld_i2c_priv * priv,u8 offs,u8 * data,u8 datalen)125 static void mlxcpld_i2c_write_comm(struct mlxcpld_i2c_priv *priv, u8 offs,
126 				   u8 *data, u8 datalen)
127 {
128 	u32 addr = priv->base_addr + offs;
129 
130 	switch (datalen) {
131 	case 1:
132 		outb(*(data), addr);
133 		break;
134 	case 2:
135 		outw(*((u16 *)data), addr);
136 		break;
137 	case 3:
138 		outw(*((u16 *)data), addr);
139 		outb(*(data + 2), addr + 2);
140 		break;
141 	case 4:
142 		outl(*((u32 *)data), addr);
143 		break;
144 	default:
145 		mlxcpld_i2c_lpc_write_buf(data, datalen, addr);
146 		break;
147 	}
148 }
149 
150 /*
151  * Check validity of received i2c messages parameters.
152  * Returns 0 if OK, other - in case of invalid parameters.
153  */
mlxcpld_i2c_check_msg_params(struct mlxcpld_i2c_priv * priv,struct i2c_msg * msgs,int num)154 static int mlxcpld_i2c_check_msg_params(struct mlxcpld_i2c_priv *priv,
155 					struct i2c_msg *msgs, int num)
156 {
157 	int i;
158 
159 	if (!num) {
160 		dev_err(priv->dev, "Incorrect 0 num of messages\n");
161 		return -EINVAL;
162 	}
163 
164 	if (unlikely(msgs[0].addr > 0x7f)) {
165 		dev_err(priv->dev, "Invalid address 0x%03x\n",
166 			msgs[0].addr);
167 		return -EINVAL;
168 	}
169 
170 	for (i = 0; i < num; ++i) {
171 		if (unlikely(!msgs[i].buf)) {
172 			dev_err(priv->dev, "Invalid buf in msg[%d]\n",
173 				i);
174 			return -EINVAL;
175 		}
176 		if (unlikely(msgs[0].addr != msgs[i].addr)) {
177 			dev_err(priv->dev, "Invalid addr in msg[%d]\n",
178 				i);
179 			return -EINVAL;
180 		}
181 	}
182 
183 	return 0;
184 }
185 
186 /*
187  * Check if transfer is completed and status of operation.
188  * Returns 0 - transfer completed (both ACK or NACK),
189  * negative - transfer isn't finished.
190  */
mlxcpld_i2c_check_status(struct mlxcpld_i2c_priv * priv,int * status)191 static int mlxcpld_i2c_check_status(struct mlxcpld_i2c_priv *priv, int *status)
192 {
193 	u8 val;
194 
195 	mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1);
196 
197 	if (val & MLXCPLD_LPCI2C_TRANS_END) {
198 		if (val & MLXCPLD_LPCI2C_STATUS_NACK)
199 			/*
200 			 * The slave is unable to accept the data. No such
201 			 * slave, command not understood, or unable to accept
202 			 * any more data.
203 			 */
204 			*status = MLXCPLD_LPCI2C_NACK_IND;
205 		else
206 			*status = MLXCPLD_LPCI2C_ACK_IND;
207 		return 0;
208 	}
209 	*status = MLXCPLD_LPCI2C_NO_IND;
210 
211 	return -EIO;
212 }
213 
mlxcpld_i2c_set_transf_data(struct mlxcpld_i2c_priv * priv,struct i2c_msg * msgs,int num,u8 comm_len)214 static void mlxcpld_i2c_set_transf_data(struct mlxcpld_i2c_priv *priv,
215 					struct i2c_msg *msgs, int num,
216 					u8 comm_len)
217 {
218 	priv->xfer.msg = msgs;
219 	priv->xfer.msg_num = num;
220 
221 	/*
222 	 * All upper layers currently are never use transfer with more than
223 	 * 2 messages. Actually, it's also not so relevant in Mellanox systems
224 	 * because of HW limitation. Max size of transfer is not more than 32
225 	 * or 68 bytes in the current x86 LPCI2C bridge.
226 	 */
227 	priv->xfer.cmd = msgs[num - 1].flags & I2C_M_RD;
228 
229 	if (priv->xfer.cmd == I2C_M_RD && comm_len != msgs[0].len) {
230 		priv->xfer.addr_width = msgs[0].len;
231 		priv->xfer.data_len = comm_len - priv->xfer.addr_width;
232 	} else {
233 		priv->xfer.addr_width = 0;
234 		priv->xfer.data_len = comm_len;
235 	}
236 }
237 
238 /* Reset CPLD LPCI2C block */
mlxcpld_i2c_reset(struct mlxcpld_i2c_priv * priv)239 static void mlxcpld_i2c_reset(struct mlxcpld_i2c_priv *priv)
240 {
241 	u8 val;
242 
243 	mutex_lock(&priv->lock);
244 
245 	mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_CTRL_REG, &val, 1);
246 	val &= ~MLXCPLD_LPCI2C_RST_SEL_MASK;
247 	mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_CTRL_REG, &val, 1);
248 
249 	mutex_unlock(&priv->lock);
250 }
251 
252 /* Make sure the CPLD is ready to start transmitting. */
mlxcpld_i2c_check_busy(struct mlxcpld_i2c_priv * priv)253 static int mlxcpld_i2c_check_busy(struct mlxcpld_i2c_priv *priv)
254 {
255 	u8 val;
256 
257 	mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1);
258 
259 	if (val & MLXCPLD_LPCI2C_TRANS_END)
260 		return 0;
261 
262 	return -EIO;
263 }
264 
mlxcpld_i2c_wait_for_free(struct mlxcpld_i2c_priv * priv)265 static int mlxcpld_i2c_wait_for_free(struct mlxcpld_i2c_priv *priv)
266 {
267 	int timeout = 0;
268 
269 	do {
270 		if (!mlxcpld_i2c_check_busy(priv))
271 			break;
272 		usleep_range(priv->polling_time / 2, priv->polling_time);
273 		timeout += priv->polling_time;
274 	} while (timeout <= MLXCPLD_I2C_XFER_TO);
275 
276 	if (timeout > MLXCPLD_I2C_XFER_TO)
277 		return -ETIMEDOUT;
278 
279 	return 0;
280 }
281 
282 /*
283  * Wait for master transfer to complete.
284  * It puts current process to sleep until we get interrupt or timeout expires.
285  * Returns the number of transferred or read bytes or error (<0).
286  */
mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv * priv)287 static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv)
288 {
289 	int status, i, timeout = 0;
290 	u8 datalen, val;
291 
292 	do {
293 		usleep_range(priv->polling_time / 2, priv->polling_time);
294 		if (!mlxcpld_i2c_check_status(priv, &status))
295 			break;
296 		timeout += priv->polling_time;
297 	} while (status == 0 && timeout < MLXCPLD_I2C_XFER_TO);
298 
299 	switch (status) {
300 	case MLXCPLD_LPCI2C_NO_IND:
301 		return -ETIMEDOUT;
302 
303 	case MLXCPLD_LPCI2C_ACK_IND:
304 		if (priv->xfer.cmd != I2C_M_RD)
305 			return (priv->xfer.addr_width + priv->xfer.data_len);
306 
307 		if (priv->xfer.msg_num == 1)
308 			i = 0;
309 		else
310 			i = 1;
311 
312 		if (!priv->xfer.msg[i].buf)
313 			return -EINVAL;
314 
315 		/*
316 		 * Actual read data len will be always the same as
317 		 * requested len. 0xff (line pull-up) will be returned
318 		 * if slave has no data to return. Thus don't read
319 		 * MLXCPLD_LPCI2C_NUM_DAT_REG reg from CPLD.  Only in case of
320 		 * SMBus block read transaction data len can be different,
321 		 * check this case.
322 		 */
323 		mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG, &val,
324 				      1);
325 		if (priv->smbus_block && (val & MLXCPLD_I2C_SMBUS_BLK_BIT)) {
326 			mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_NUM_DAT_REG,
327 					      &datalen, 1);
328 			if (unlikely(datalen > I2C_SMBUS_BLOCK_MAX)) {
329 				dev_err(priv->dev, "Incorrect smbus block read message len\n");
330 				return -EPROTO;
331 			}
332 		} else {
333 			datalen = priv->xfer.data_len;
334 		}
335 
336 		mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_DATA_REG,
337 				      priv->xfer.msg[i].buf, datalen);
338 
339 		return datalen;
340 
341 	case MLXCPLD_LPCI2C_NACK_IND:
342 		return -ENXIO;
343 
344 	default:
345 		return -EINVAL;
346 	}
347 }
348 
mlxcpld_i2c_xfer_msg(struct mlxcpld_i2c_priv * priv)349 static void mlxcpld_i2c_xfer_msg(struct mlxcpld_i2c_priv *priv)
350 {
351 	int i, len = 0;
352 	u8 cmd, val;
353 
354 	mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_DAT_REG,
355 			       &priv->xfer.data_len, 1);
356 
357 	val = priv->xfer.addr_width;
358 	/* Notify HW about SMBus block read transaction */
359 	if (priv->smbus_block && priv->xfer.msg_num >= 2 &&
360 	    priv->xfer.msg[1].len == 1 &&
361 	    (priv->xfer.msg[1].flags & I2C_M_RECV_LEN) &&
362 	    (priv->xfer.msg[1].flags & I2C_M_RD))
363 		val |= MLXCPLD_I2C_SMBUS_BLK_BIT;
364 
365 	mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG, &val, 1);
366 
367 	for (i = 0; i < priv->xfer.msg_num; i++) {
368 		if ((priv->xfer.msg[i].flags & I2C_M_RD) != I2C_M_RD) {
369 			/* Don't write to CPLD buffer in read transaction */
370 			mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_DATA_REG +
371 					       len, priv->xfer.msg[i].buf,
372 					       priv->xfer.msg[i].len);
373 			len += priv->xfer.msg[i].len;
374 		}
375 	}
376 
377 	/*
378 	 * Set target slave address with command for master transfer.
379 	 * It should be latest executed function before CPLD transaction.
380 	 */
381 	cmd = (priv->xfer.msg[0].addr << 1) | priv->xfer.cmd;
382 	mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_CMD_REG, &cmd, 1);
383 }
384 
385 /*
386  * Generic lpc-i2c transfer.
387  * Returns the number of processed messages or error (<0).
388  */
mlxcpld_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)389 static int mlxcpld_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
390 			    int num)
391 {
392 	struct mlxcpld_i2c_priv *priv = i2c_get_adapdata(adap);
393 	u8 comm_len = 0;
394 	int i, err;
395 
396 	err = mlxcpld_i2c_check_msg_params(priv, msgs, num);
397 	if (err) {
398 		dev_err(priv->dev, "Incorrect message\n");
399 		return err;
400 	}
401 
402 	for (i = 0; i < num; ++i)
403 		comm_len += msgs[i].len;
404 
405 	/* Check bus state */
406 	if (mlxcpld_i2c_wait_for_free(priv)) {
407 		dev_err(priv->dev, "LPCI2C bridge is busy\n");
408 
409 		/*
410 		 * Usually it means something serious has happened.
411 		 * We can not have unfinished previous transfer
412 		 * so it doesn't make any sense to try to stop it.
413 		 * Probably we were not able to recover from the
414 		 * previous error.
415 		 * The only reasonable thing - is soft reset.
416 		 */
417 		mlxcpld_i2c_reset(priv);
418 		if (mlxcpld_i2c_check_busy(priv)) {
419 			dev_err(priv->dev, "LPCI2C bridge is busy after reset\n");
420 			return -EIO;
421 		}
422 	}
423 
424 	mlxcpld_i2c_set_transf_data(priv, msgs, num, comm_len);
425 
426 	mutex_lock(&priv->lock);
427 
428 	/* Do real transfer. Can't fail */
429 	mlxcpld_i2c_xfer_msg(priv);
430 
431 	/* Wait for transaction complete */
432 	err = mlxcpld_i2c_wait_for_tc(priv);
433 
434 	mutex_unlock(&priv->lock);
435 
436 	return err < 0 ? err : num;
437 }
438 
mlxcpld_i2c_func(struct i2c_adapter * adap)439 static u32 mlxcpld_i2c_func(struct i2c_adapter *adap)
440 {
441 	struct mlxcpld_i2c_priv *priv = i2c_get_adapdata(adap);
442 
443 	if (priv->smbus_block)
444 		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
445 			I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_BLOCK_DATA;
446 	else
447 		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
448 			I2C_FUNC_SMBUS_I2C_BLOCK;
449 }
450 
451 static const struct i2c_algorithm mlxcpld_i2c_algo = {
452 	.master_xfer	= mlxcpld_i2c_xfer,
453 	.functionality	= mlxcpld_i2c_func
454 };
455 
456 static const struct i2c_adapter_quirks mlxcpld_i2c_quirks = {
457 	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
458 	.max_read_len = MLXCPLD_I2C_DATA_REG_SZ - MLXCPLD_I2C_MAX_ADDR_LEN,
459 	.max_write_len = MLXCPLD_I2C_DATA_REG_SZ,
460 	.max_comb_1st_msg_len = 4,
461 };
462 
463 static const struct i2c_adapter_quirks mlxcpld_i2c_quirks_ext = {
464 	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
465 	.max_read_len = MLXCPLD_I2C_DATA_REG_SZ * 2 - MLXCPLD_I2C_MAX_ADDR_LEN,
466 	.max_write_len = MLXCPLD_I2C_DATA_REG_SZ * 2,
467 	.max_comb_1st_msg_len = 4,
468 };
469 
470 static const struct i2c_adapter_quirks mlxcpld_i2c_quirks_ext2 = {
471 	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
472 	.max_read_len = (MLXCPLD_I2C_DATA_REG_SZ - 4) * 4,
473 	.max_write_len = (MLXCPLD_I2C_DATA_REG_SZ - 4) * 4 + MLXCPLD_I2C_MAX_ADDR_LEN,
474 	.max_comb_1st_msg_len = 4,
475 };
476 
477 static struct i2c_adapter mlxcpld_i2c_adapter = {
478 	.owner          = THIS_MODULE,
479 	.name           = "i2c-mlxcpld",
480 	.class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
481 	.algo           = &mlxcpld_i2c_algo,
482 	.quirks		= &mlxcpld_i2c_quirks,
483 	.retries	= MLXCPLD_I2C_RETR_NUM,
484 	.nr		= MLXCPLD_I2C_BUS_NUM,
485 };
486 
487 static int
mlxcpld_i2c_set_frequency(struct mlxcpld_i2c_priv * priv,struct mlxreg_core_hotplug_platform_data * pdata)488 mlxcpld_i2c_set_frequency(struct mlxcpld_i2c_priv *priv,
489 			  struct mlxreg_core_hotplug_platform_data *pdata)
490 {
491 	struct mlxreg_core_item *item = pdata->items;
492 	struct mlxreg_core_data *data;
493 	u32 regval;
494 	u8 freq;
495 	int err;
496 
497 	if (!item)
498 		return 0;
499 
500 	/* Read frequency setting. */
501 	data = item->data;
502 	err = regmap_read(pdata->regmap, data->reg, &regval);
503 	if (err)
504 		return err;
505 
506 	/* Set frequency only if it is not 100KHz, which is default. */
507 	switch ((regval & data->mask) >> data->bit) {
508 	case MLXCPLD_I2C_FREQ_1000KHZ:
509 		freq = MLXCPLD_I2C_FREQ_1000KHZ_SET;
510 		priv->polling_time /= 4;
511 		break;
512 	case MLXCPLD_I2C_FREQ_400KHZ:
513 		freq = MLXCPLD_I2C_FREQ_400KHZ_SET;
514 		priv->polling_time /= 4;
515 		break;
516 	default:
517 		return 0;
518 	}
519 
520 	mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_HALF_CYC_REG, &freq, 1);
521 
522 	return 0;
523 }
524 
mlxcpld_i2c_probe(struct platform_device * pdev)525 static int mlxcpld_i2c_probe(struct platform_device *pdev)
526 {
527 	struct mlxreg_core_hotplug_platform_data *pdata;
528 	struct mlxcpld_i2c_priv *priv;
529 	int err;
530 	u8 val;
531 
532 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
533 	if (!priv)
534 		return -ENOMEM;
535 
536 	mutex_init(&priv->lock);
537 	platform_set_drvdata(pdev, priv);
538 
539 	priv->dev = &pdev->dev;
540 	priv->base_addr = MLXPLAT_CPLD_LPC_I2C_BASE_ADDR;
541 	priv->polling_time = MLXCPLD_I2C_POLL_TIME;
542 
543 	/* Set I2C bus frequency if platform data provides this info. */
544 	pdata = dev_get_platdata(&pdev->dev);
545 	if (pdata) {
546 		err = mlxcpld_i2c_set_frequency(priv, pdata);
547 		if (err)
548 			goto mlxcpld_i2_probe_failed;
549 	}
550 
551 	/* Register with i2c layer */
552 	mlxcpld_i2c_adapter.timeout = usecs_to_jiffies(MLXCPLD_I2C_XFER_TO);
553 	/* Read capability register */
554 	mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_CPBLTY_REG, &val, 1);
555 	/* Check support for extended transaction length */
556 	if ((val & MLXCPLD_I2C_DATA_SZ_MASK) == MLXCPLD_I2C_DATA_SZ_BIT)
557 		mlxcpld_i2c_adapter.quirks = &mlxcpld_i2c_quirks_ext;
558 	else if ((val & MLXCPLD_I2C_DATA_SZ_MASK) == MLXCPLD_I2C_DATA_EXT2_SZ_BIT)
559 		mlxcpld_i2c_adapter.quirks = &mlxcpld_i2c_quirks_ext2;
560 	/* Check support for smbus block transaction */
561 	if (val & MLXCPLD_I2C_SMBUS_BLK_BIT)
562 		priv->smbus_block = true;
563 	if (pdev->id >= -1)
564 		mlxcpld_i2c_adapter.nr = pdev->id;
565 	priv->adap = mlxcpld_i2c_adapter;
566 	priv->adap.dev.parent = &pdev->dev;
567 	i2c_set_adapdata(&priv->adap, priv);
568 
569 	err = i2c_add_numbered_adapter(&priv->adap);
570 	if (err)
571 		goto mlxcpld_i2_probe_failed;
572 
573 	/* Notify caller when adapter is added. */
574 	if (pdata && pdata->completion_notify)
575 		pdata->completion_notify(pdata->handle, mlxcpld_i2c_adapter.nr);
576 
577 	return 0;
578 
579 mlxcpld_i2_probe_failed:
580 	mutex_destroy(&priv->lock);
581 	return err;
582 }
583 
mlxcpld_i2c_remove(struct platform_device * pdev)584 static void mlxcpld_i2c_remove(struct platform_device *pdev)
585 {
586 	struct mlxcpld_i2c_priv *priv = platform_get_drvdata(pdev);
587 
588 	i2c_del_adapter(&priv->adap);
589 	mutex_destroy(&priv->lock);
590 }
591 
592 static struct platform_driver mlxcpld_i2c_driver = {
593 	.probe		= mlxcpld_i2c_probe,
594 	.remove_new	= mlxcpld_i2c_remove,
595 	.driver = {
596 		.name = MLXCPLD_I2C_DEVICE_NAME,
597 	},
598 };
599 
600 module_platform_driver(mlxcpld_i2c_driver);
601 
602 MODULE_AUTHOR("Michael Shych <michaels@mellanox.com>");
603 MODULE_DESCRIPTION("Mellanox I2C-CPLD controller driver");
604 MODULE_LICENSE("Dual BSD/GPL");
605 MODULE_ALIAS("platform:i2c-mlxcpld");
606