1 /*
2 * Specific bus support for PMC-TWI compliant implementation on MSP71xx.
3 *
4 * Copyright 2005-2007 PMC-Sierra, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
12 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
14 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
15 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
16 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
17 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
18 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
19 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
20 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/platform_device.h>
26 #include <linux/i2c.h>
27 #include <linux/interrupt.h>
28 #include <linux/completion.h>
29 #include <linux/mutex.h>
30 #include <linux/delay.h>
31 #include <linux/io.h>
32
33 #define DRV_NAME "pmcmsptwi"
34
35 #define MSP_TWI_SF_CLK_REG_OFFSET 0x00
36 #define MSP_TWI_HS_CLK_REG_OFFSET 0x04
37 #define MSP_TWI_CFG_REG_OFFSET 0x08
38 #define MSP_TWI_CMD_REG_OFFSET 0x0c
39 #define MSP_TWI_ADD_REG_OFFSET 0x10
40 #define MSP_TWI_DAT_0_REG_OFFSET 0x14
41 #define MSP_TWI_DAT_1_REG_OFFSET 0x18
42 #define MSP_TWI_INT_STS_REG_OFFSET 0x1c
43 #define MSP_TWI_INT_MSK_REG_OFFSET 0x20
44 #define MSP_TWI_BUSY_REG_OFFSET 0x24
45
46 #define MSP_TWI_INT_STS_DONE (1 << 0)
47 #define MSP_TWI_INT_STS_LOST_ARBITRATION (1 << 1)
48 #define MSP_TWI_INT_STS_NO_RESPONSE (1 << 2)
49 #define MSP_TWI_INT_STS_DATA_COLLISION (1 << 3)
50 #define MSP_TWI_INT_STS_BUSY (1 << 4)
51 #define MSP_TWI_INT_STS_ALL 0x1f
52
53 #define MSP_MAX_BYTES_PER_RW 8
54 #define MSP_MAX_POLL 5
55 #define MSP_POLL_DELAY 10
56 #define MSP_IRQ_TIMEOUT (MSP_MAX_POLL * MSP_POLL_DELAY)
57
58 /* IO Operation macros */
59 #define pmcmsptwi_readl __raw_readl
60 #define pmcmsptwi_writel __raw_writel
61
62 /* TWI command type */
63 enum pmcmsptwi_cmd_type {
64 MSP_TWI_CMD_WRITE = 0, /* Write only */
65 MSP_TWI_CMD_READ = 1, /* Read only */
66 MSP_TWI_CMD_WRITE_READ = 2, /* Write then Read */
67 };
68
69 /* The possible results of the xferCmd */
70 enum pmcmsptwi_xfer_result {
71 MSP_TWI_XFER_OK = 0,
72 MSP_TWI_XFER_TIMEOUT,
73 MSP_TWI_XFER_BUSY,
74 MSP_TWI_XFER_DATA_COLLISION,
75 MSP_TWI_XFER_NO_RESPONSE,
76 MSP_TWI_XFER_LOST_ARBITRATION,
77 };
78
79 /* Corresponds to a PMCTWI clock configuration register */
80 struct pmcmsptwi_clock {
81 u8 filter; /* Bits 15:12, default = 0x03 */
82 u16 clock; /* Bits 9:0, default = 0x001f */
83 };
84
85 struct pmcmsptwi_clockcfg {
86 struct pmcmsptwi_clock standard; /* The standard/fast clock config */
87 struct pmcmsptwi_clock highspeed; /* The highspeed clock config */
88 };
89
90 /* Corresponds to the main TWI configuration register */
91 struct pmcmsptwi_cfg {
92 u8 arbf; /* Bits 15:12, default=0x03 */
93 u8 nak; /* Bits 11:8, default=0x03 */
94 u8 add10; /* Bit 7, default=0x00 */
95 u8 mst_code; /* Bits 6:4, default=0x00 */
96 u8 arb; /* Bit 1, default=0x01 */
97 u8 highspeed; /* Bit 0, default=0x00 */
98 };
99
100 /* A single pmctwi command to issue */
101 struct pmcmsptwi_cmd {
102 u16 addr; /* The slave address (7 or 10 bits) */
103 enum pmcmsptwi_cmd_type type; /* The command type */
104 u8 write_len; /* Number of bytes in the write buffer */
105 u8 read_len; /* Number of bytes in the read buffer */
106 u8 *write_data; /* Buffer of characters to send */
107 u8 *read_data; /* Buffer to fill with incoming data */
108 };
109
110 /* The private data */
111 struct pmcmsptwi_data {
112 void __iomem *iobase; /* iomapped base for IO */
113 int irq; /* IRQ to use (0 disables) */
114 struct completion wait; /* Completion for xfer */
115 struct mutex lock; /* Used for threadsafeness */
116 enum pmcmsptwi_xfer_result last_result; /* result of last xfer */
117 };
118
119 /* The default settings */
120 static const struct pmcmsptwi_clockcfg pmcmsptwi_defclockcfg = {
121 .standard = {
122 .filter = 0x3,
123 .clock = 0x1f,
124 },
125 .highspeed = {
126 .filter = 0x3,
127 .clock = 0x1f,
128 },
129 };
130
131 static const struct pmcmsptwi_cfg pmcmsptwi_defcfg = {
132 .arbf = 0x03,
133 .nak = 0x03,
134 .add10 = 0x00,
135 .mst_code = 0x00,
136 .arb = 0x01,
137 .highspeed = 0x00,
138 };
139
140 static struct pmcmsptwi_data pmcmsptwi_data;
141
142 static struct i2c_adapter pmcmsptwi_adapter;
143
144 /* inline helper functions */
pmcmsptwi_clock_to_reg(const struct pmcmsptwi_clock * clock)145 static inline u32 pmcmsptwi_clock_to_reg(
146 const struct pmcmsptwi_clock *clock)
147 {
148 return ((clock->filter & 0xf) << 12) | (clock->clock & 0x03ff);
149 }
150
pmcmsptwi_cfg_to_reg(const struct pmcmsptwi_cfg * cfg)151 static inline u32 pmcmsptwi_cfg_to_reg(const struct pmcmsptwi_cfg *cfg)
152 {
153 return ((cfg->arbf & 0xf) << 12) |
154 ((cfg->nak & 0xf) << 8) |
155 ((cfg->add10 & 0x1) << 7) |
156 ((cfg->mst_code & 0x7) << 4) |
157 ((cfg->arb & 0x1) << 1) |
158 (cfg->highspeed & 0x1);
159 }
160
pmcmsptwi_reg_to_cfg(u32 reg,struct pmcmsptwi_cfg * cfg)161 static inline void pmcmsptwi_reg_to_cfg(u32 reg, struct pmcmsptwi_cfg *cfg)
162 {
163 cfg->arbf = (reg >> 12) & 0xf;
164 cfg->nak = (reg >> 8) & 0xf;
165 cfg->add10 = (reg >> 7) & 0x1;
166 cfg->mst_code = (reg >> 4) & 0x7;
167 cfg->arb = (reg >> 1) & 0x1;
168 cfg->highspeed = reg & 0x1;
169 }
170
171 /*
172 * Sets the current clock configuration
173 */
pmcmsptwi_set_clock_config(const struct pmcmsptwi_clockcfg * cfg,struct pmcmsptwi_data * data)174 static void pmcmsptwi_set_clock_config(const struct pmcmsptwi_clockcfg *cfg,
175 struct pmcmsptwi_data *data)
176 {
177 mutex_lock(&data->lock);
178 pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->standard),
179 data->iobase + MSP_TWI_SF_CLK_REG_OFFSET);
180 pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->highspeed),
181 data->iobase + MSP_TWI_HS_CLK_REG_OFFSET);
182 mutex_unlock(&data->lock);
183 }
184
185 /*
186 * Gets the current TWI bus configuration
187 */
pmcmsptwi_get_twi_config(struct pmcmsptwi_cfg * cfg,struct pmcmsptwi_data * data)188 static void pmcmsptwi_get_twi_config(struct pmcmsptwi_cfg *cfg,
189 struct pmcmsptwi_data *data)
190 {
191 mutex_lock(&data->lock);
192 pmcmsptwi_reg_to_cfg(pmcmsptwi_readl(
193 data->iobase + MSP_TWI_CFG_REG_OFFSET), cfg);
194 mutex_unlock(&data->lock);
195 }
196
197 /*
198 * Sets the current TWI bus configuration
199 */
pmcmsptwi_set_twi_config(const struct pmcmsptwi_cfg * cfg,struct pmcmsptwi_data * data)200 static void pmcmsptwi_set_twi_config(const struct pmcmsptwi_cfg *cfg,
201 struct pmcmsptwi_data *data)
202 {
203 mutex_lock(&data->lock);
204 pmcmsptwi_writel(pmcmsptwi_cfg_to_reg(cfg),
205 data->iobase + MSP_TWI_CFG_REG_OFFSET);
206 mutex_unlock(&data->lock);
207 }
208
209 /*
210 * Parses the 'int_sts' register and returns a well-defined error code
211 */
pmcmsptwi_get_result(u32 reg)212 static enum pmcmsptwi_xfer_result pmcmsptwi_get_result(u32 reg)
213 {
214 if (reg & MSP_TWI_INT_STS_LOST_ARBITRATION) {
215 dev_dbg(&pmcmsptwi_adapter.dev,
216 "Result: Lost arbitration\n");
217 return MSP_TWI_XFER_LOST_ARBITRATION;
218 } else if (reg & MSP_TWI_INT_STS_NO_RESPONSE) {
219 dev_dbg(&pmcmsptwi_adapter.dev,
220 "Result: No response\n");
221 return MSP_TWI_XFER_NO_RESPONSE;
222 } else if (reg & MSP_TWI_INT_STS_DATA_COLLISION) {
223 dev_dbg(&pmcmsptwi_adapter.dev,
224 "Result: Data collision\n");
225 return MSP_TWI_XFER_DATA_COLLISION;
226 } else if (reg & MSP_TWI_INT_STS_BUSY) {
227 dev_dbg(&pmcmsptwi_adapter.dev,
228 "Result: Bus busy\n");
229 return MSP_TWI_XFER_BUSY;
230 }
231
232 dev_dbg(&pmcmsptwi_adapter.dev, "Result: Operation succeeded\n");
233 return MSP_TWI_XFER_OK;
234 }
235
236 /*
237 * In interrupt mode, handle the interrupt.
238 * NOTE: Assumes data->lock is held.
239 */
pmcmsptwi_interrupt(int irq,void * ptr)240 static irqreturn_t pmcmsptwi_interrupt(int irq, void *ptr)
241 {
242 struct pmcmsptwi_data *data = ptr;
243
244 u32 reason = pmcmsptwi_readl(data->iobase +
245 MSP_TWI_INT_STS_REG_OFFSET);
246 pmcmsptwi_writel(reason, data->iobase + MSP_TWI_INT_STS_REG_OFFSET);
247
248 dev_dbg(&pmcmsptwi_adapter.dev, "Got interrupt 0x%08x\n", reason);
249 if (!(reason & MSP_TWI_INT_STS_DONE))
250 return IRQ_NONE;
251
252 data->last_result = pmcmsptwi_get_result(reason);
253 complete(&data->wait);
254
255 return IRQ_HANDLED;
256 }
257
258 /*
259 * Probe for and register the device and return 0 if there is one.
260 */
pmcmsptwi_probe(struct platform_device * pldev)261 static int pmcmsptwi_probe(struct platform_device *pldev)
262 {
263 struct resource *res;
264 int rc = -ENODEV;
265
266 /* get the static platform resources */
267 res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
268 if (!res) {
269 dev_err(&pldev->dev, "IOMEM resource not found\n");
270 goto ret_err;
271 }
272
273 /* reserve the memory region */
274 if (!request_mem_region(res->start, resource_size(res),
275 pldev->name)) {
276 dev_err(&pldev->dev,
277 "Unable to get memory/io address region %pap\n",
278 &res->start);
279 rc = -EBUSY;
280 goto ret_err;
281 }
282
283 /* remap the memory */
284 pmcmsptwi_data.iobase = ioremap(res->start,
285 resource_size(res));
286 if (!pmcmsptwi_data.iobase) {
287 dev_err(&pldev->dev,
288 "Unable to ioremap address %pap\n", &res->start);
289 rc = -EIO;
290 goto ret_unreserve;
291 }
292
293 /* request the irq */
294 pmcmsptwi_data.irq = platform_get_irq(pldev, 0);
295 if (pmcmsptwi_data.irq) {
296 rc = request_irq(pmcmsptwi_data.irq, &pmcmsptwi_interrupt,
297 IRQF_SHARED, pldev->name, &pmcmsptwi_data);
298 if (rc == 0) {
299 /*
300 * Enable 'DONE' interrupt only.
301 *
302 * If you enable all interrupts, you will get one on
303 * error and another when the operation completes.
304 * This way you only have to handle one interrupt,
305 * but you can still check all result flags.
306 */
307 pmcmsptwi_writel(MSP_TWI_INT_STS_DONE,
308 pmcmsptwi_data.iobase +
309 MSP_TWI_INT_MSK_REG_OFFSET);
310 } else {
311 dev_warn(&pldev->dev,
312 "Could not assign TWI IRQ handler "
313 "to irq %d (continuing with poll)\n",
314 pmcmsptwi_data.irq);
315 pmcmsptwi_data.irq = 0;
316 }
317 }
318
319 init_completion(&pmcmsptwi_data.wait);
320 mutex_init(&pmcmsptwi_data.lock);
321
322 pmcmsptwi_set_clock_config(&pmcmsptwi_defclockcfg, &pmcmsptwi_data);
323 pmcmsptwi_set_twi_config(&pmcmsptwi_defcfg, &pmcmsptwi_data);
324
325 printk(KERN_INFO DRV_NAME ": Registering MSP71xx I2C adapter\n");
326
327 pmcmsptwi_adapter.dev.parent = &pldev->dev;
328 platform_set_drvdata(pldev, &pmcmsptwi_adapter);
329 i2c_set_adapdata(&pmcmsptwi_adapter, &pmcmsptwi_data);
330
331 rc = i2c_add_adapter(&pmcmsptwi_adapter);
332 if (rc)
333 goto ret_unmap;
334
335 return 0;
336
337 ret_unmap:
338 if (pmcmsptwi_data.irq) {
339 pmcmsptwi_writel(0,
340 pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET);
341 free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data);
342 }
343
344 iounmap(pmcmsptwi_data.iobase);
345
346 ret_unreserve:
347 release_mem_region(res->start, resource_size(res));
348
349 ret_err:
350 return rc;
351 }
352
353 /*
354 * Release the device and return 0 if there is one.
355 */
pmcmsptwi_remove(struct platform_device * pldev)356 static int pmcmsptwi_remove(struct platform_device *pldev)
357 {
358 struct resource *res;
359
360 i2c_del_adapter(&pmcmsptwi_adapter);
361
362 if (pmcmsptwi_data.irq) {
363 pmcmsptwi_writel(0,
364 pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET);
365 free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data);
366 }
367
368 iounmap(pmcmsptwi_data.iobase);
369
370 res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
371 release_mem_region(res->start, resource_size(res));
372
373 return 0;
374 }
375
376 /*
377 * Polls the 'busy' register until the command is complete.
378 * NOTE: Assumes data->lock is held.
379 */
pmcmsptwi_poll_complete(struct pmcmsptwi_data * data)380 static void pmcmsptwi_poll_complete(struct pmcmsptwi_data *data)
381 {
382 int i;
383
384 for (i = 0; i < MSP_MAX_POLL; i++) {
385 u32 val = pmcmsptwi_readl(data->iobase +
386 MSP_TWI_BUSY_REG_OFFSET);
387 if (val == 0) {
388 u32 reason = pmcmsptwi_readl(data->iobase +
389 MSP_TWI_INT_STS_REG_OFFSET);
390 pmcmsptwi_writel(reason, data->iobase +
391 MSP_TWI_INT_STS_REG_OFFSET);
392 data->last_result = pmcmsptwi_get_result(reason);
393 return;
394 }
395 udelay(MSP_POLL_DELAY);
396 }
397
398 dev_dbg(&pmcmsptwi_adapter.dev, "Result: Poll timeout\n");
399 data->last_result = MSP_TWI_XFER_TIMEOUT;
400 }
401
402 /*
403 * Do the transfer (low level):
404 * May use interrupt-driven or polling, depending on if an IRQ is
405 * presently registered.
406 * NOTE: Assumes data->lock is held.
407 */
pmcmsptwi_do_xfer(u32 reg,struct pmcmsptwi_data * data)408 static enum pmcmsptwi_xfer_result pmcmsptwi_do_xfer(
409 u32 reg, struct pmcmsptwi_data *data)
410 {
411 dev_dbg(&pmcmsptwi_adapter.dev, "Writing cmd reg 0x%08x\n", reg);
412 pmcmsptwi_writel(reg, data->iobase + MSP_TWI_CMD_REG_OFFSET);
413 if (data->irq) {
414 unsigned long timeleft = wait_for_completion_timeout(
415 &data->wait, MSP_IRQ_TIMEOUT);
416 if (timeleft == 0) {
417 dev_dbg(&pmcmsptwi_adapter.dev,
418 "Result: IRQ timeout\n");
419 complete(&data->wait);
420 data->last_result = MSP_TWI_XFER_TIMEOUT;
421 }
422 } else
423 pmcmsptwi_poll_complete(data);
424
425 return data->last_result;
426 }
427
428 /*
429 * Helper routine, converts 'pmctwi_cmd' struct to register format
430 */
pmcmsptwi_cmd_to_reg(const struct pmcmsptwi_cmd * cmd)431 static inline u32 pmcmsptwi_cmd_to_reg(const struct pmcmsptwi_cmd *cmd)
432 {
433 return ((cmd->type & 0x3) << 8) |
434 (((cmd->write_len - 1) & 0x7) << 4) |
435 ((cmd->read_len - 1) & 0x7);
436 }
437
438 /*
439 * Do the transfer (high level)
440 */
pmcmsptwi_xfer_cmd(struct pmcmsptwi_cmd * cmd,struct pmcmsptwi_data * data)441 static enum pmcmsptwi_xfer_result pmcmsptwi_xfer_cmd(
442 struct pmcmsptwi_cmd *cmd,
443 struct pmcmsptwi_data *data)
444 {
445 enum pmcmsptwi_xfer_result retval;
446
447 mutex_lock(&data->lock);
448 dev_dbg(&pmcmsptwi_adapter.dev,
449 "Setting address to 0x%04x\n", cmd->addr);
450 pmcmsptwi_writel(cmd->addr, data->iobase + MSP_TWI_ADD_REG_OFFSET);
451
452 if (cmd->type == MSP_TWI_CMD_WRITE ||
453 cmd->type == MSP_TWI_CMD_WRITE_READ) {
454 u64 tmp = be64_to_cpup((__be64 *)cmd->write_data);
455 tmp >>= (MSP_MAX_BYTES_PER_RW - cmd->write_len) * 8;
456 dev_dbg(&pmcmsptwi_adapter.dev, "Writing 0x%016llx\n", tmp);
457 pmcmsptwi_writel(tmp & 0x00000000ffffffffLL,
458 data->iobase + MSP_TWI_DAT_0_REG_OFFSET);
459 if (cmd->write_len > 4)
460 pmcmsptwi_writel(tmp >> 32,
461 data->iobase + MSP_TWI_DAT_1_REG_OFFSET);
462 }
463
464 retval = pmcmsptwi_do_xfer(pmcmsptwi_cmd_to_reg(cmd), data);
465 if (retval != MSP_TWI_XFER_OK)
466 goto xfer_err;
467
468 if (cmd->type == MSP_TWI_CMD_READ ||
469 cmd->type == MSP_TWI_CMD_WRITE_READ) {
470 int i;
471 u64 rmsk = ~(0xffffffffffffffffLL << (cmd->read_len * 8));
472 u64 tmp = (u64)pmcmsptwi_readl(data->iobase +
473 MSP_TWI_DAT_0_REG_OFFSET);
474 if (cmd->read_len > 4)
475 tmp |= (u64)pmcmsptwi_readl(data->iobase +
476 MSP_TWI_DAT_1_REG_OFFSET) << 32;
477 tmp &= rmsk;
478 dev_dbg(&pmcmsptwi_adapter.dev, "Read 0x%016llx\n", tmp);
479
480 for (i = 0; i < cmd->read_len; i++)
481 cmd->read_data[i] = tmp >> i;
482 }
483
484 xfer_err:
485 mutex_unlock(&data->lock);
486
487 return retval;
488 }
489
490 /* -- Algorithm functions -- */
491
492 /*
493 * Sends an i2c command out on the adapter
494 */
pmcmsptwi_master_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int num)495 static int pmcmsptwi_master_xfer(struct i2c_adapter *adap,
496 struct i2c_msg *msg, int num)
497 {
498 struct pmcmsptwi_data *data = i2c_get_adapdata(adap);
499 struct pmcmsptwi_cmd cmd;
500 struct pmcmsptwi_cfg oldcfg, newcfg;
501 int ret;
502
503 if (num == 2) {
504 struct i2c_msg *nextmsg = msg + 1;
505
506 cmd.type = MSP_TWI_CMD_WRITE_READ;
507 cmd.write_len = msg->len;
508 cmd.write_data = msg->buf;
509 cmd.read_len = nextmsg->len;
510 cmd.read_data = nextmsg->buf;
511 } else if (msg->flags & I2C_M_RD) {
512 cmd.type = MSP_TWI_CMD_READ;
513 cmd.read_len = msg->len;
514 cmd.read_data = msg->buf;
515 cmd.write_len = 0;
516 cmd.write_data = NULL;
517 } else {
518 cmd.type = MSP_TWI_CMD_WRITE;
519 cmd.read_len = 0;
520 cmd.read_data = NULL;
521 cmd.write_len = msg->len;
522 cmd.write_data = msg->buf;
523 }
524
525 cmd.addr = msg->addr;
526
527 if (msg->flags & I2C_M_TEN) {
528 pmcmsptwi_get_twi_config(&newcfg, data);
529 memcpy(&oldcfg, &newcfg, sizeof(oldcfg));
530
531 /* Set the special 10-bit address flag */
532 newcfg.add10 = 1;
533
534 pmcmsptwi_set_twi_config(&newcfg, data);
535 }
536
537 /* Execute the command */
538 ret = pmcmsptwi_xfer_cmd(&cmd, data);
539
540 if (msg->flags & I2C_M_TEN)
541 pmcmsptwi_set_twi_config(&oldcfg, data);
542
543 dev_dbg(&adap->dev, "I2C %s of %d bytes %s\n",
544 (msg->flags & I2C_M_RD) ? "read" : "write", msg->len,
545 (ret == MSP_TWI_XFER_OK) ? "succeeded" : "failed");
546
547 if (ret != MSP_TWI_XFER_OK) {
548 /*
549 * TODO: We could potentially loop and retry in the case
550 * of MSP_TWI_XFER_TIMEOUT.
551 */
552 return -EIO;
553 }
554
555 return num;
556 }
557
pmcmsptwi_i2c_func(struct i2c_adapter * adapter)558 static u32 pmcmsptwi_i2c_func(struct i2c_adapter *adapter)
559 {
560 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
561 I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
562 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL;
563 }
564
565 static const struct i2c_adapter_quirks pmcmsptwi_i2c_quirks = {
566 .flags = I2C_AQ_COMB_WRITE_THEN_READ | I2C_AQ_NO_ZERO_LEN,
567 .max_write_len = MSP_MAX_BYTES_PER_RW,
568 .max_read_len = MSP_MAX_BYTES_PER_RW,
569 .max_comb_1st_msg_len = MSP_MAX_BYTES_PER_RW,
570 .max_comb_2nd_msg_len = MSP_MAX_BYTES_PER_RW,
571 };
572
573 /* -- Initialization -- */
574
575 static const struct i2c_algorithm pmcmsptwi_algo = {
576 .master_xfer = pmcmsptwi_master_xfer,
577 .functionality = pmcmsptwi_i2c_func,
578 };
579
580 static struct i2c_adapter pmcmsptwi_adapter = {
581 .owner = THIS_MODULE,
582 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
583 .algo = &pmcmsptwi_algo,
584 .quirks = &pmcmsptwi_i2c_quirks,
585 .name = DRV_NAME,
586 };
587
588 static struct platform_driver pmcmsptwi_driver = {
589 .probe = pmcmsptwi_probe,
590 .remove = pmcmsptwi_remove,
591 .driver = {
592 .name = DRV_NAME,
593 },
594 };
595
596 module_platform_driver(pmcmsptwi_driver);
597
598 MODULE_DESCRIPTION("PMC MSP TWI/SMBus/I2C driver");
599 MODULE_LICENSE("GPL");
600 MODULE_ALIAS("platform:" DRV_NAME);
601