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diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c
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1/*
2 * This file is provided under a dual BSD/GPLv2 license. When using or
3 * redistributing this file, you may do so under either license.
4 *
5 * Copyright(c) 2012 Intel Corporation. All rights reserved.
6 *
7 * GPL LICENSE SUMMARY
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of version 2 of the GNU General Public License as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21 * The full GNU General Public License is included in this distribution
22 * in the file called LICENSE.GPL.
23 *
24 * BSD LICENSE
25 *
26 * Redistribution and use in source and binary forms, with or without
27 * modification, are permitted provided that the following conditions
28 * are met:
29 *
30 * * Redistributions of source code must retain the above copyright
31 * notice, this list of conditions and the following disclaimer.
32 * * Redistributions in binary form must reproduce the above copyright
33 * notice, this list of conditions and the following disclaimer in
34 * the documentation and/or other materials provided with the
35 * distribution.
36 * * Neither the name of Intel Corporation nor the names of its
37 * contributors may be used to endorse or promote products derived
38 * from this software without specific prior written permission.
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
41 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
42 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
43 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
44 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
46 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
47 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
48 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
49 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
50 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51 */
52
53/*
54 * Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
55 * S12xx Product Family.
56 *
57 * Features supported by this driver:
58 * Hardware PEC yes
59 * Block buffer yes
60 * Block process call transaction no
61 * Slave mode no
62 */
63
64#include <linux/module.h>
65#include <linux/init.h>
66#include <linux/pci.h>
67#include <linux/kernel.h>
68#include <linux/stddef.h>
69#include <linux/completion.h>
70#include <linux/dma-mapping.h>
71#include <linux/i2c.h>
72#include <linux/acpi.h>
73#include <linux/interrupt.h>
74
75#include <asm-generic/io-64-nonatomic-lo-hi.h>
76
77/* PCI Address Constants */
78#define SMBBAR 0
79
80/* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
81#define PCI_DEVICE_ID_INTEL_S1200_SMT0 0x0c59
82#define PCI_DEVICE_ID_INTEL_S1200_SMT1 0x0c5a
83
84#define ISMT_DESC_ENTRIES 32 /* number of descriptor entries */
85#define ISMT_MAX_RETRIES 3 /* number of SMBus retries to attempt */
86
87/* Hardware Descriptor Constants - Control Field */
88#define ISMT_DESC_CWRL 0x01 /* Command/Write Length */
89#define ISMT_DESC_BLK 0X04 /* Perform Block Transaction */
90#define ISMT_DESC_FAIR 0x08 /* Set fairness flag upon successful arbit. */
91#define ISMT_DESC_PEC 0x10 /* Packet Error Code */
92#define ISMT_DESC_I2C 0x20 /* I2C Enable */
93#define ISMT_DESC_INT 0x40 /* Interrupt */
94#define ISMT_DESC_SOE 0x80 /* Stop On Error */
95
96/* Hardware Descriptor Constants - Status Field */
97#define ISMT_DESC_SCS 0x01 /* Success */
98#define ISMT_DESC_DLTO 0x04 /* Data Low Time Out */
99#define ISMT_DESC_NAK 0x08 /* NAK Received */
100#define ISMT_DESC_CRC 0x10 /* CRC Error */
101#define ISMT_DESC_CLTO 0x20 /* Clock Low Time Out */
102#define ISMT_DESC_COL 0x40 /* Collisions */
103#define ISMT_DESC_LPR 0x80 /* Large Packet Received */
104
105/* Macros */
106#define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
107
108/* iSMT General Register address offsets (SMBBAR + <addr>) */
109#define ISMT_GR_GCTRL 0x000 /* General Control */
110#define ISMT_GR_SMTICL 0x008 /* SMT Interrupt Cause Location */
111#define ISMT_GR_ERRINTMSK 0x010 /* Error Interrupt Mask */
112#define ISMT_GR_ERRAERMSK 0x014 /* Error AER Mask */
113#define ISMT_GR_ERRSTS 0x018 /* Error Status */
114#define ISMT_GR_ERRINFO 0x01c /* Error Information */
115
116/* iSMT Master Registers */
117#define ISMT_MSTR_MDBA 0x100 /* Master Descriptor Base Address */
118#define ISMT_MSTR_MCTRL 0x108 /* Master Control */
119#define ISMT_MSTR_MSTS 0x10c /* Master Status */
120#define ISMT_MSTR_MDS 0x110 /* Master Descriptor Size */
121#define ISMT_MSTR_RPOLICY 0x114 /* Retry Policy */
122
123/* iSMT Miscellaneous Registers */
124#define ISMT_SPGT 0x300 /* SMBus PHY Global Timing */
125
126/* General Control Register (GCTRL) bit definitions */
127#define ISMT_GCTRL_TRST 0x04 /* Target Reset */
128#define ISMT_GCTRL_KILL 0x08 /* Kill */
129#define ISMT_GCTRL_SRST 0x40 /* Soft Reset */
130
131/* Master Control Register (MCTRL) bit definitions */
132#define ISMT_MCTRL_SS 0x01 /* Start/Stop */
133#define ISMT_MCTRL_MEIE 0x10 /* Master Error Interrupt Enable */
134#define ISMT_MCTRL_FMHP 0x00ff0000 /* Firmware Master Head Ptr (FMHP) */
135
136/* Master Status Register (MSTS) bit definitions */
137#define ISMT_MSTS_HMTP 0xff0000 /* HW Master Tail Pointer (HMTP) */
138#define ISMT_MSTS_MIS 0x20 /* Master Interrupt Status (MIS) */
139#define ISMT_MSTS_MEIS 0x10 /* Master Error Int Status (MEIS) */
140#define ISMT_MSTS_IP 0x01 /* In Progress */
141
142/* Master Descriptor Size (MDS) bit definitions */
143#define ISMT_MDS_MASK 0xff /* Master Descriptor Size mask (MDS) */
144
145/* SMBus PHY Global Timing Register (SPGT) bit definitions */
146#define ISMT_SPGT_SPD_MASK 0xc0000000 /* SMBus Speed mask */
147#define ISMT_SPGT_SPD_80K 0x00 /* 80 kHz */
148#define ISMT_SPGT_SPD_100K (0x1 << 30) /* 100 kHz */
149#define ISMT_SPGT_SPD_400K (0x2 << 30) /* 400 kHz */
150#define ISMT_SPGT_SPD_1M (0x3 << 30) /* 1 MHz */
151
152
153/* MSI Control Register (MSICTL) bit definitions */
154#define ISMT_MSICTL_MSIE 0x01 /* MSI Enable */
155
156/* iSMT Hardware Descriptor */
157struct ismt_desc {
158 u8 tgtaddr_rw; /* target address & r/w bit */
159 u8 wr_len_cmd; /* write length in bytes or a command */
160 u8 rd_len; /* read length */
161 u8 control; /* control bits */
162 u8 status; /* status bits */
163 u8 retry; /* collision retry and retry count */
164 u8 rxbytes; /* received bytes */
165 u8 txbytes; /* transmitted bytes */
166 u32 dptr_low; /* lower 32 bit of the data pointer */
167 u32 dptr_high; /* upper 32 bit of the data pointer */
168} __packed;
169
170struct ismt_priv {
171 struct i2c_adapter adapter;
172 void *smba; /* PCI BAR */
173 struct pci_dev *pci_dev;
174 struct ismt_desc *hw; /* descriptor virt base addr */
175 dma_addr_t io_rng_dma; /* descriptor HW base addr */
176 u8 head; /* ring buffer head pointer */
177 struct completion cmp; /* interrupt completion */
178 u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
179 bool using_msi; /* type of interrupt flag */
180};
181
182/**
183 * ismt_ids - PCI device IDs supported by this driver
184 */
185static const DEFINE_PCI_DEVICE_TABLE(ismt_ids) = {
186 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
187 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
188 { 0, }
189};
190
191MODULE_DEVICE_TABLE(pci, ismt_ids);
192
193/* Bus speed control bits for slow debuggers - refer to the docs for usage */
194static unsigned int bus_speed;
195module_param(bus_speed, uint, S_IRUGO);
196MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
197
198/**
199 * __ismt_desc_dump() - dump the contents of a specific descriptor
200 */
201static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
202{
203
204 dev_dbg(dev, "Descriptor struct: %p\n", desc);
205 dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
206 dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
207 dev_dbg(dev, "\trd_len= 0x%02X\n", desc->rd_len);
208 dev_dbg(dev, "\tcontrol= 0x%02X\n", desc->control);
209 dev_dbg(dev, "\tstatus= 0x%02X\n", desc->status);
210 dev_dbg(dev, "\tretry= 0x%02X\n", desc->retry);
211 dev_dbg(dev, "\trxbytes= 0x%02X\n", desc->rxbytes);
212 dev_dbg(dev, "\ttxbytes= 0x%02X\n", desc->txbytes);
213 dev_dbg(dev, "\tdptr_low= 0x%08X\n", desc->dptr_low);
214 dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
215}
216/**
217 * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
218 * @priv: iSMT private data
219 */
220static void ismt_desc_dump(struct ismt_priv *priv)
221{
222 struct device *dev = &priv->pci_dev->dev;
223 struct ismt_desc *desc = &priv->hw[priv->head];
224
225 dev_dbg(dev, "Dump of the descriptor struct: 0x%X\n", priv->head);
226 __ismt_desc_dump(dev, desc);
227}
228
229/**
230 * ismt_gen_reg_dump() - dump the iSMT General Registers
231 * @priv: iSMT private data
232 */
233static void ismt_gen_reg_dump(struct ismt_priv *priv)
234{
235 struct device *dev = &priv->pci_dev->dev;
236
237 dev_dbg(dev, "Dump of the iSMT General Registers\n");
238 dev_dbg(dev, " GCTRL.... : (0x%p)=0x%X\n",
239 priv->smba + ISMT_GR_GCTRL,
240 readl(priv->smba + ISMT_GR_GCTRL));
241 dev_dbg(dev, " SMTICL... : (0x%p)=0x%016llX\n",
242 priv->smba + ISMT_GR_SMTICL,
243 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
244 dev_dbg(dev, " ERRINTMSK : (0x%p)=0x%X\n",
245 priv->smba + ISMT_GR_ERRINTMSK,
246 readl(priv->smba + ISMT_GR_ERRINTMSK));
247 dev_dbg(dev, " ERRAERMSK : (0x%p)=0x%X\n",
248 priv->smba + ISMT_GR_ERRAERMSK,
249 readl(priv->smba + ISMT_GR_ERRAERMSK));
250 dev_dbg(dev, " ERRSTS... : (0x%p)=0x%X\n",
251 priv->smba + ISMT_GR_ERRSTS,
252 readl(priv->smba + ISMT_GR_ERRSTS));
253 dev_dbg(dev, " ERRINFO.. : (0x%p)=0x%X\n",
254 priv->smba + ISMT_GR_ERRINFO,
255 readl(priv->smba + ISMT_GR_ERRINFO));
256}
257
258/**
259 * ismt_mstr_reg_dump() - dump the iSMT Master Registers
260 * @priv: iSMT private data
261 */
262static void ismt_mstr_reg_dump(struct ismt_priv *priv)
263{
264 struct device *dev = &priv->pci_dev->dev;
265
266 dev_dbg(dev, "Dump of the iSMT Master Registers\n");
267 dev_dbg(dev, " MDBA..... : (0x%p)=0x%016llX\n",
268 priv->smba + ISMT_MSTR_MDBA,
269 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
270 dev_dbg(dev, " MCTRL.... : (0x%p)=0x%X\n",
271 priv->smba + ISMT_MSTR_MCTRL,
272 readl(priv->smba + ISMT_MSTR_MCTRL));
273 dev_dbg(dev, " MSTS..... : (0x%p)=0x%X\n",
274 priv->smba + ISMT_MSTR_MSTS,
275 readl(priv->smba + ISMT_MSTR_MSTS));
276 dev_dbg(dev, " MDS...... : (0x%p)=0x%X\n",
277 priv->smba + ISMT_MSTR_MDS,
278 readl(priv->smba + ISMT_MSTR_MDS));
279 dev_dbg(dev, " RPOLICY.. : (0x%p)=0x%X\n",
280 priv->smba + ISMT_MSTR_RPOLICY,
281 readl(priv->smba + ISMT_MSTR_RPOLICY));
282 dev_dbg(dev, " SPGT..... : (0x%p)=0x%X\n",
283 priv->smba + ISMT_SPGT,
284 readl(priv->smba + ISMT_SPGT));
285}
286
287/**
288 * ismt_submit_desc() - add a descriptor to the ring
289 * @priv: iSMT private data
290 */
291static void ismt_submit_desc(struct ismt_priv *priv)
292{
293 uint fmhp;
294 uint val;
295
296 ismt_desc_dump(priv);
297 ismt_gen_reg_dump(priv);
298 ismt_mstr_reg_dump(priv);
299
300 /* Set the FMHP (Firmware Master Head Pointer)*/
301 fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
302 val = readl(priv->smba + ISMT_MSTR_MCTRL);
303 writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
304 priv->smba + ISMT_MSTR_MCTRL);
305
306 /* Set the start bit */
307 val = readl(priv->smba + ISMT_MSTR_MCTRL);
308 writel(val | ISMT_MCTRL_SS,
309 priv->smba + ISMT_MSTR_MCTRL);
310}
311
312/**
313 * ismt_process_desc() - handle the completion of the descriptor
314 * @desc: the iSMT hardware descriptor
315 * @data: data buffer from the upper layer
316 * @priv: ismt_priv struct holding our dma buffer
317 * @size: SMBus transaction type
318 * @read_write: flag to indicate if this is a read or write
319 */
320static int ismt_process_desc(const struct ismt_desc *desc,
321 union i2c_smbus_data *data,
322 struct ismt_priv *priv, int size,
323 char read_write)
324{
325 u8 *dma_buffer = priv->dma_buffer;
326
327 dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
328 __ismt_desc_dump(&priv->pci_dev->dev, desc);
329
330 if (desc->status & ISMT_DESC_SCS) {
331 if (read_write == I2C_SMBUS_WRITE &&
332 size != I2C_SMBUS_PROC_CALL)
333 return 0;
334
335 switch (size) {
336 case I2C_SMBUS_BYTE:
337 case I2C_SMBUS_BYTE_DATA:
338 data->byte = dma_buffer[0];
339 break;
340 case I2C_SMBUS_WORD_DATA:
341 case I2C_SMBUS_PROC_CALL:
342 data->word = dma_buffer[0] | (dma_buffer[1] << 8);
343 break;
344 case I2C_SMBUS_BLOCK_DATA:
345 memcpy(&data->block[1], dma_buffer, desc->rxbytes);
346 data->block[0] = desc->rxbytes;
347 break;
348 }
349 return 0;
350 }
351
352 if (likely(desc->status & ISMT_DESC_NAK))
353 return -ENXIO;
354
355 if (desc->status & ISMT_DESC_CRC)
356 return -EBADMSG;
357
358 if (desc->status & ISMT_DESC_COL)
359 return -EAGAIN;
360
361 if (desc->status & ISMT_DESC_LPR)
362 return -EPROTO;
363
364 if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
365 return -ETIMEDOUT;
366
367 return -EIO;
368}
369
370/**
371 * ismt_access() - process an SMBus command
372 * @adap: the i2c host adapter
373 * @addr: address of the i2c/SMBus target
374 * @flags: command options
375 * @read_write: read from or write to device
376 * @command: the i2c/SMBus command to issue
377 * @size: SMBus transaction type
378 * @data: read/write data buffer
379 */
380static int ismt_access(struct i2c_adapter *adap, u16 addr,
381 unsigned short flags, char read_write, u8 command,
382 int size, union i2c_smbus_data *data)
383{
384 int ret;
385 dma_addr_t dma_addr = 0; /* address of the data buffer */
386 u8 dma_size = 0;
387 enum dma_data_direction dma_direction = 0;
388 struct ismt_desc *desc;
389 struct ismt_priv *priv = i2c_get_adapdata(adap);
390 struct device *dev = &priv->pci_dev->dev;
391
392 desc = &priv->hw[priv->head];
393
394 /* Initialize the descriptor */
395 memset(desc, 0, sizeof(struct ismt_desc));
396 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
397
398 /* Initialize common control bits */
399 if (likely(priv->using_msi))
400 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
401 else
402 desc->control = ISMT_DESC_FAIR;
403
404 if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
405 && (size != I2C_SMBUS_I2C_BLOCK_DATA))
406 desc->control |= ISMT_DESC_PEC;
407
408 switch (size) {
409 case I2C_SMBUS_QUICK:
410 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
411 break;
412
413 case I2C_SMBUS_BYTE:
414 if (read_write == I2C_SMBUS_WRITE) {
415 /*
416 * Send Byte
417 * The command field contains the write data
418 */
419 dev_dbg(dev, "I2C_SMBUS_BYTE: WRITE\n");
420 desc->control |= ISMT_DESC_CWRL;
421 desc->wr_len_cmd = command;
422 } else {
423 /* Receive Byte */
424 dev_dbg(dev, "I2C_SMBUS_BYTE: READ\n");
425 dma_size = 1;
426 dma_direction = DMA_FROM_DEVICE;
427 desc->rd_len = 1;
428 }
429 break;
430
431 case I2C_SMBUS_BYTE_DATA:
432 if (read_write == I2C_SMBUS_WRITE) {
433 /*
434 * Write Byte
435 * Command plus 1 data byte
436 */
437 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
438 desc->wr_len_cmd = 2;
439 dma_size = 2;
440 dma_direction = DMA_TO_DEVICE;
441 priv->dma_buffer[0] = command;
442 priv->dma_buffer[1] = data->byte;
443 } else {
444 /* Read Byte */
445 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: READ\n");
446 desc->control |= ISMT_DESC_CWRL;
447 desc->wr_len_cmd = command;
448 desc->rd_len = 1;
449 dma_size = 1;
450 dma_direction = DMA_FROM_DEVICE;
451 }
452 break;
453
454 case I2C_SMBUS_WORD_DATA:
455 if (read_write == I2C_SMBUS_WRITE) {
456 /* Write Word */
457 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
458 desc->wr_len_cmd = 3;
459 dma_size = 3;
460 dma_direction = DMA_TO_DEVICE;
461 priv->dma_buffer[0] = command;
462 priv->dma_buffer[1] = data->word & 0xff;
463 priv->dma_buffer[2] = data->word >> 8;
464 } else {
465 /* Read Word */
466 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: READ\n");
467 desc->wr_len_cmd = command;
468 desc->control |= ISMT_DESC_CWRL;
469 desc->rd_len = 2;
470 dma_size = 2;
471 dma_direction = DMA_FROM_DEVICE;
472 }
473 break;
474
475 case I2C_SMBUS_PROC_CALL:
476 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
477 desc->wr_len_cmd = 3;
478 desc->rd_len = 2;
479 dma_size = 3;
480 dma_direction = DMA_BIDIRECTIONAL;
481 priv->dma_buffer[0] = command;
482 priv->dma_buffer[1] = data->word & 0xff;
483 priv->dma_buffer[2] = data->word >> 8;
484 break;
485
486 case I2C_SMBUS_BLOCK_DATA:
487 if (read_write == I2C_SMBUS_WRITE) {
488 /* Block Write */
489 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n");
490 dma_size = data->block[0] + 1;
491 dma_direction = DMA_TO_DEVICE;
492 desc->wr_len_cmd = dma_size;
493 desc->control |= ISMT_DESC_BLK;
494 priv->dma_buffer[0] = command;
495 memcpy(&priv->dma_buffer[1], &data->block[1], dma_size);
496 } else {
497 /* Block Read */
498 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
499 dma_size = I2C_SMBUS_BLOCK_MAX;
500 dma_direction = DMA_FROM_DEVICE;
501 desc->rd_len = dma_size;
502 desc->wr_len_cmd = command;
503 desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
504 }
505 break;
506
507 default:
508 dev_err(dev, "Unsupported transaction %d\n",
509 size);
510 return -EOPNOTSUPP;
511 }
512
513 /* map the data buffer */
514 if (dma_size != 0) {
515 dev_dbg(dev, " dev=%p\n", dev);
516 dev_dbg(dev, " data=%p\n", data);
517 dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
518 dev_dbg(dev, " dma_size=%d\n", dma_size);
519 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
520
521 dma_addr = dma_map_single(dev,
522 priv->dma_buffer,
523 dma_size,
524 dma_direction);
525
526 if (dma_mapping_error(dev, dma_addr)) {
527 dev_err(dev, "Error in mapping dma buffer %p\n",
528 priv->dma_buffer);
529 return -EIO;
530 }
531
532 dev_dbg(dev, " dma_addr = 0x%016llX\n",
533 (unsigned long long)dma_addr);
534
535 desc->dptr_low = lower_32_bits(dma_addr);
536 desc->dptr_high = upper_32_bits(dma_addr);
537 }
538
539 INIT_COMPLETION(priv->cmp);
540
541 /* Add the descriptor */
542 ismt_submit_desc(priv);
543
544 /* Now we wait for interrupt completion, 1s */
545 ret = wait_for_completion_timeout(&priv->cmp, HZ*1);
546
547 /* unmap the data buffer */
548 if (dma_size != 0)
549 dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
550
551 if (unlikely(!ret)) {
552 dev_err(dev, "completion wait timed out\n");
553 ret = -ETIMEDOUT;
554 goto out;
555 }
556
557 /* do any post processing of the descriptor here */
558 ret = ismt_process_desc(desc, data, priv, size, read_write);
559
560out:
561 /* Update the ring pointer */
562 priv->head++;
563 priv->head %= ISMT_DESC_ENTRIES;
564
565 return ret;
566}
567
568/**
569 * ismt_func() - report which i2c commands are supported by this adapter
570 * @adap: the i2c host adapter
571 */
572static u32 ismt_func(struct i2c_adapter *adap)
573{
574 return I2C_FUNC_SMBUS_QUICK |
575 I2C_FUNC_SMBUS_BYTE |
576 I2C_FUNC_SMBUS_BYTE_DATA |
577 I2C_FUNC_SMBUS_WORD_DATA |
578 I2C_FUNC_SMBUS_PROC_CALL |
579 I2C_FUNC_SMBUS_BLOCK_DATA |
580 I2C_FUNC_SMBUS_PEC;
581}
582
583/**
584 * smbus_algorithm - the adapter algorithm and supported functionality
585 * @smbus_xfer: the adapter algorithm
586 * @functionality: functionality supported by the adapter
587 */
588static const struct i2c_algorithm smbus_algorithm = {
589 .smbus_xfer = ismt_access,
590 .functionality = ismt_func,
591};
592
593/**
594 * ismt_handle_isr() - interrupt handler bottom half
595 * @priv: iSMT private data
596 */
597static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
598{
599 complete(&priv->cmp);
600
601 return IRQ_HANDLED;
602}
603
604
605/**
606 * ismt_do_interrupt() - IRQ interrupt handler
607 * @vec: interrupt vector
608 * @data: iSMT private data
609 */
610static irqreturn_t ismt_do_interrupt(int vec, void *data)
611{
612 u32 val;
613 struct ismt_priv *priv = data;
614
615 /*
616 * check to see it's our interrupt, return IRQ_NONE if not ours
617 * since we are sharing interrupt
618 */
619 val = readl(priv->smba + ISMT_MSTR_MSTS);
620
621 if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
622 return IRQ_NONE;
623 else
624 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
625 priv->smba + ISMT_MSTR_MSTS);
626
627 return ismt_handle_isr(priv);
628}
629
630/**
631 * ismt_do_msi_interrupt() - MSI interrupt handler
632 * @vec: interrupt vector
633 * @data: iSMT private data
634 */
635static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
636{
637 return ismt_handle_isr(data);
638}
639
640/**
641 * ismt_hw_init() - initialize the iSMT hardware
642 * @priv: iSMT private data
643 */
644static void ismt_hw_init(struct ismt_priv *priv)
645{
646 u32 val;
647 struct device *dev = &priv->pci_dev->dev;
648
649 /* initialize the Master Descriptor Base Address (MDBA) */
650 writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
651
652 /* initialize the Master Control Register (MCTRL) */
653 writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
654
655 /* initialize the Master Status Register (MSTS) */
656 writel(0, priv->smba + ISMT_MSTR_MSTS);
657
658 /* initialize the Master Descriptor Size (MDS) */
659 val = readl(priv->smba + ISMT_MSTR_MDS);
660 writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
661 priv->smba + ISMT_MSTR_MDS);
662
663 /*
664 * Set the SMBus speed (could use this for slow HW debuggers)
665 */
666
667 val = readl(priv->smba + ISMT_SPGT);
668
669 switch (bus_speed) {
670 case 0:
671 break;
672
673 case 80:
674 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
675 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
676 priv->smba + ISMT_SPGT);
677 break;
678
679 case 100:
680 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
681 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
682 priv->smba + ISMT_SPGT);
683 break;
684
685 case 400:
686 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
687 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
688 priv->smba + ISMT_SPGT);
689 break;
690
691 case 1000:
692 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
693 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
694 priv->smba + ISMT_SPGT);
695 break;
696
697 default:
698 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
699 break;
700 }
701
702 val = readl(priv->smba + ISMT_SPGT);
703
704 switch (val & ISMT_SPGT_SPD_MASK) {
705 case ISMT_SPGT_SPD_80K:
706 bus_speed = 80;
707 break;
708 case ISMT_SPGT_SPD_100K:
709 bus_speed = 100;
710 break;
711 case ISMT_SPGT_SPD_400K:
712 bus_speed = 400;
713 break;
714 case ISMT_SPGT_SPD_1M:
715 bus_speed = 1000;
716 break;
717 }
718 dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
719}
720
721/**
722 * ismt_dev_init() - initialize the iSMT data structures
723 * @priv: iSMT private data
724 */
725static int ismt_dev_init(struct ismt_priv *priv)
726{
727 /* allocate memory for the descriptor */
728 priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
729 (ISMT_DESC_ENTRIES
730 * sizeof(struct ismt_desc)),
731 &priv->io_rng_dma,
732 GFP_KERNEL);
733 if (!priv->hw)
734 return -ENOMEM;
735
736 memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
737
738 priv->head = 0;
739 init_completion(&priv->cmp);
740
741 return 0;
742}
743
744/**
745 * ismt_int_init() - initialize interrupts
746 * @priv: iSMT private data
747 */
748static int ismt_int_init(struct ismt_priv *priv)
749{
750 int err;
751
752 /* Try using MSI interrupts */
753 err = pci_enable_msi(priv->pci_dev);
754 if (err) {
755 dev_warn(&priv->pci_dev->dev,
756 "Unable to use MSI interrupts, falling back to legacy\n");
757 goto intx;
758 }
759
760 err = devm_request_irq(&priv->pci_dev->dev,
761 priv->pci_dev->irq,
762 ismt_do_msi_interrupt,
763 0,
764 "ismt-msi",
765 priv);
766 if (err) {
767 pci_disable_msi(priv->pci_dev);
768 goto intx;
769 }
770
771 priv->using_msi = true;
772 goto done;
773
774 /* Try using legacy interrupts */
775intx:
776 err = devm_request_irq(&priv->pci_dev->dev,
777 priv->pci_dev->irq,
778 ismt_do_interrupt,
779 IRQF_SHARED,
780 "ismt-intx",
781 priv);
782 if (err) {
783 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
784 return -ENODEV;
785 }
786
787 priv->using_msi = false;
788
789done:
790 return 0;
791}
792
793static struct pci_driver ismt_driver;
794
795/**
796 * ismt_probe() - probe for iSMT devices
797 * @pdev: PCI-Express device
798 * @id: PCI-Express device ID
799 */
800static int
801ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
802{
803 int err;
804 struct ismt_priv *priv;
805 unsigned long start, len;
806
807 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
808 if (!priv)
809 return -ENOMEM;
810
811 pci_set_drvdata(pdev, priv);
812 i2c_set_adapdata(&priv->adapter, priv);
813 priv->adapter.owner = THIS_MODULE;
814
815 priv->adapter.class = I2C_CLASS_HWMON;
816
817 priv->adapter.algo = &smbus_algorithm;
818
819 /* set up the sysfs linkage to our parent device */
820 priv->adapter.dev.parent = &pdev->dev;
821
822 /* number of retries on lost arbitration */
823 priv->adapter.retries = ISMT_MAX_RETRIES;
824
825 priv->pci_dev = pdev;
826
827 err = pcim_enable_device(pdev);
828 if (err) {
829 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
830 err);
831 return err;
832 }
833
834 /* enable bus mastering */
835 pci_set_master(pdev);
836
837 /* Determine the address of the SMBus area */
838 start = pci_resource_start(pdev, SMBBAR);
839 len = pci_resource_len(pdev, SMBBAR);
840 if (!start || !len) {
841 dev_err(&pdev->dev,
842 "SMBus base address uninitialized, upgrade BIOS\n");
843 return -ENODEV;
844 }
845
846 snprintf(priv->adapter.name, sizeof(priv->adapter.name),
847 "SMBus iSMT adapter at %lx", start);
848
849 dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
850 dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
851
852 err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
853 if (err) {
854 dev_err(&pdev->dev, "ACPI resource conflict!\n");
855 return err;
856 }
857
858 err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
859 if (err) {
860 dev_err(&pdev->dev,
861 "Failed to request SMBus region 0x%lx-0x%lx\n",
862 start, start + len);
863 return err;
864 }
865
866 priv->smba = pcim_iomap(pdev, SMBBAR, len);
867 if (!priv->smba) {
868 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
869 err = -ENODEV;
870 goto fail;
871 }
872
873 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
874 (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
875 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
876 (pci_set_consistent_dma_mask(pdev,
877 DMA_BIT_MASK(32)) != 0)) {
878 dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
879 pdev);
880 goto fail;
881 }
882 }
883
884 err = ismt_dev_init(priv);
885 if (err)
886 goto fail;
887
888 ismt_hw_init(priv);
889
890 err = ismt_int_init(priv);
891 if (err)
892 goto fail;
893
894 err = i2c_add_adapter(&priv->adapter);
895 if (err) {
896 dev_err(&pdev->dev, "Failed to add SMBus iSMT adapter\n");
897 err = -ENODEV;
898 goto fail;
899 }
900 return 0;
901
902fail:
903 pci_release_region(pdev, SMBBAR);
904 return err;
905}
906
907/**
908 * ismt_remove() - release driver resources
909 * @pdev: PCI-Express device
910 */
911static void ismt_remove(struct pci_dev *pdev)
912{
913 struct ismt_priv *priv = pci_get_drvdata(pdev);
914
915 i2c_del_adapter(&priv->adapter);
916 pci_release_region(pdev, SMBBAR);
917}
918
919/**
920 * ismt_suspend() - place the device in suspend
921 * @pdev: PCI-Express device
922 * @mesg: PM message
923 */
924#ifdef CONFIG_PM
925static int ismt_suspend(struct pci_dev *pdev, pm_message_t mesg)
926{
927 pci_save_state(pdev);
928 pci_set_power_state(pdev, pci_choose_state(pdev, mesg));
929 return 0;
930}
931
932/**
933 * ismt_resume() - PCI resume code
934 * @pdev: PCI-Express device
935 */
936static int ismt_resume(struct pci_dev *pdev)
937{
938 pci_set_power_state(pdev, PCI_D0);
939 pci_restore_state(pdev);
940 return pci_enable_device(pdev);
941}
942
943#else
944
945#define ismt_suspend NULL
946#define ismt_resume NULL
947
948#endif
949
950static struct pci_driver ismt_driver = {
951 .name = "ismt_smbus",
952 .id_table = ismt_ids,
953 .probe = ismt_probe,
954 .remove = ismt_remove,
955 .suspend = ismt_suspend,
956 .resume = ismt_resume,
957};
958
959module_pci_driver(ismt_driver);
960
961MODULE_LICENSE("Dual BSD/GPL");
962MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
963MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-01 12:00:00 -0500