dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / i2c / busses / i2c-ismt.c
blobfa2b58142cded12198a349fa1562ad34f044db36
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.
5 * Copyright(c) 2012 Intel Corporation. All rights reserved.
7 * GPL LICENSE SUMMARY
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.
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 * The full GNU General Public License is included in this distribution
18 * in the file called LICENSE.GPL.
20 * BSD LICENSE
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
26 * * Redistributions of source code must retain the above copyright
27 * notice, this list of conditions and the following disclaimer.
28 * * Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in
30 * the documentation and/or other materials provided with the
31 * distribution.
32 * * Neither the name of Intel Corporation nor the names of its
33 * contributors may be used to endorse or promote products derived
34 * from this software without specific prior written permission.
36 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
37 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
38 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
39 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
40 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
43 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
44 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
45 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
46 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50 * Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
51 * S12xx Product Family.
53 * Features supported by this driver:
54 * Hardware PEC yes
55 * Block buffer yes
56 * Block process call transaction no
57 * Slave mode no
60 #include <linux/module.h>
61 #include <linux/pci.h>
62 #include <linux/kernel.h>
63 #include <linux/stddef.h>
64 #include <linux/completion.h>
65 #include <linux/dma-mapping.h>
66 #include <linux/i2c.h>
67 #include <linux/acpi.h>
68 #include <linux/interrupt.h>
70 #include <linux/io-64-nonatomic-lo-hi.h>
72 /* PCI Address Constants */
73 #define SMBBAR 0
75 /* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
76 #define PCI_DEVICE_ID_INTEL_S1200_SMT0 0x0c59
77 #define PCI_DEVICE_ID_INTEL_S1200_SMT1 0x0c5a
78 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT 0x1f15
80 #define ISMT_DESC_ENTRIES 2 /* number of descriptor entries */
81 #define ISMT_MAX_RETRIES 3 /* number of SMBus retries to attempt */
83 /* Hardware Descriptor Constants - Control Field */
84 #define ISMT_DESC_CWRL 0x01 /* Command/Write Length */
85 #define ISMT_DESC_BLK 0X04 /* Perform Block Transaction */
86 #define ISMT_DESC_FAIR 0x08 /* Set fairness flag upon successful arbit. */
87 #define ISMT_DESC_PEC 0x10 /* Packet Error Code */
88 #define ISMT_DESC_I2C 0x20 /* I2C Enable */
89 #define ISMT_DESC_INT 0x40 /* Interrupt */
90 #define ISMT_DESC_SOE 0x80 /* Stop On Error */
92 /* Hardware Descriptor Constants - Status Field */
93 #define ISMT_DESC_SCS 0x01 /* Success */
94 #define ISMT_DESC_DLTO 0x04 /* Data Low Time Out */
95 #define ISMT_DESC_NAK 0x08 /* NAK Received */
96 #define ISMT_DESC_CRC 0x10 /* CRC Error */
97 #define ISMT_DESC_CLTO 0x20 /* Clock Low Time Out */
98 #define ISMT_DESC_COL 0x40 /* Collisions */
99 #define ISMT_DESC_LPR 0x80 /* Large Packet Received */
101 /* Macros */
102 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
104 /* iSMT General Register address offsets (SMBBAR + <addr>) */
105 #define ISMT_GR_GCTRL 0x000 /* General Control */
106 #define ISMT_GR_SMTICL 0x008 /* SMT Interrupt Cause Location */
107 #define ISMT_GR_ERRINTMSK 0x010 /* Error Interrupt Mask */
108 #define ISMT_GR_ERRAERMSK 0x014 /* Error AER Mask */
109 #define ISMT_GR_ERRSTS 0x018 /* Error Status */
110 #define ISMT_GR_ERRINFO 0x01c /* Error Information */
112 /* iSMT Master Registers */
113 #define ISMT_MSTR_MDBA 0x100 /* Master Descriptor Base Address */
114 #define ISMT_MSTR_MCTRL 0x108 /* Master Control */
115 #define ISMT_MSTR_MSTS 0x10c /* Master Status */
116 #define ISMT_MSTR_MDS 0x110 /* Master Descriptor Size */
117 #define ISMT_MSTR_RPOLICY 0x114 /* Retry Policy */
119 /* iSMT Miscellaneous Registers */
120 #define ISMT_SPGT 0x300 /* SMBus PHY Global Timing */
122 /* General Control Register (GCTRL) bit definitions */
123 #define ISMT_GCTRL_TRST 0x04 /* Target Reset */
124 #define ISMT_GCTRL_KILL 0x08 /* Kill */
125 #define ISMT_GCTRL_SRST 0x40 /* Soft Reset */
127 /* Master Control Register (MCTRL) bit definitions */
128 #define ISMT_MCTRL_SS 0x01 /* Start/Stop */
129 #define ISMT_MCTRL_MEIE 0x10 /* Master Error Interrupt Enable */
130 #define ISMT_MCTRL_FMHP 0x00ff0000 /* Firmware Master Head Ptr (FMHP) */
132 /* Master Status Register (MSTS) bit definitions */
133 #define ISMT_MSTS_HMTP 0xff0000 /* HW Master Tail Pointer (HMTP) */
134 #define ISMT_MSTS_MIS 0x20 /* Master Interrupt Status (MIS) */
135 #define ISMT_MSTS_MEIS 0x10 /* Master Error Int Status (MEIS) */
136 #define ISMT_MSTS_IP 0x01 /* In Progress */
138 /* Master Descriptor Size (MDS) bit definitions */
139 #define ISMT_MDS_MASK 0xff /* Master Descriptor Size mask (MDS) */
141 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
142 #define ISMT_SPGT_SPD_MASK 0xc0000000 /* SMBus Speed mask */
143 #define ISMT_SPGT_SPD_80K 0x00 /* 80 kHz */
144 #define ISMT_SPGT_SPD_100K (0x1 << 30) /* 100 kHz */
145 #define ISMT_SPGT_SPD_400K (0x2 << 30) /* 400 kHz */
146 #define ISMT_SPGT_SPD_1M (0x3 << 30) /* 1 MHz */
149 /* MSI Control Register (MSICTL) bit definitions */
150 #define ISMT_MSICTL_MSIE 0x01 /* MSI Enable */
152 /* iSMT Hardware Descriptor */
153 struct ismt_desc {
154 u8 tgtaddr_rw; /* target address & r/w bit */
155 u8 wr_len_cmd; /* write length in bytes or a command */
156 u8 rd_len; /* read length */
157 u8 control; /* control bits */
158 u8 status; /* status bits */
159 u8 retry; /* collision retry and retry count */
160 u8 rxbytes; /* received bytes */
161 u8 txbytes; /* transmitted bytes */
162 u32 dptr_low; /* lower 32 bit of the data pointer */
163 u32 dptr_high; /* upper 32 bit of the data pointer */
164 } __packed;
166 struct ismt_priv {
167 struct i2c_adapter adapter;
168 void __iomem *smba; /* PCI BAR */
169 struct pci_dev *pci_dev;
170 struct ismt_desc *hw; /* descriptor virt base addr */
171 dma_addr_t io_rng_dma; /* descriptor HW base addr */
172 u8 head; /* ring buffer head pointer */
173 struct completion cmp; /* interrupt completion */
174 u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
178 * ismt_ids - PCI device IDs supported by this driver
180 static const struct pci_device_id ismt_ids[] = {
181 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
182 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
183 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
184 { 0, }
187 MODULE_DEVICE_TABLE(pci, ismt_ids);
189 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
190 static unsigned int bus_speed;
191 module_param(bus_speed, uint, S_IRUGO);
192 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
195 * __ismt_desc_dump() - dump the contents of a specific descriptor
197 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
200 dev_dbg(dev, "Descriptor struct: %p\n", desc);
201 dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
202 dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
203 dev_dbg(dev, "\trd_len= 0x%02X\n", desc->rd_len);
204 dev_dbg(dev, "\tcontrol= 0x%02X\n", desc->control);
205 dev_dbg(dev, "\tstatus= 0x%02X\n", desc->status);
206 dev_dbg(dev, "\tretry= 0x%02X\n", desc->retry);
207 dev_dbg(dev, "\trxbytes= 0x%02X\n", desc->rxbytes);
208 dev_dbg(dev, "\ttxbytes= 0x%02X\n", desc->txbytes);
209 dev_dbg(dev, "\tdptr_low= 0x%08X\n", desc->dptr_low);
210 dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
213 * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
214 * @priv: iSMT private data
216 static void ismt_desc_dump(struct ismt_priv *priv)
218 struct device *dev = &priv->pci_dev->dev;
219 struct ismt_desc *desc = &priv->hw[priv->head];
221 dev_dbg(dev, "Dump of the descriptor struct: 0x%X\n", priv->head);
222 __ismt_desc_dump(dev, desc);
226 * ismt_gen_reg_dump() - dump the iSMT General Registers
227 * @priv: iSMT private data
229 static void ismt_gen_reg_dump(struct ismt_priv *priv)
231 struct device *dev = &priv->pci_dev->dev;
233 dev_dbg(dev, "Dump of the iSMT General Registers\n");
234 dev_dbg(dev, " GCTRL.... : (0x%p)=0x%X\n",
235 priv->smba + ISMT_GR_GCTRL,
236 readl(priv->smba + ISMT_GR_GCTRL));
237 dev_dbg(dev, " SMTICL... : (0x%p)=0x%016llX\n",
238 priv->smba + ISMT_GR_SMTICL,
239 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
240 dev_dbg(dev, " ERRINTMSK : (0x%p)=0x%X\n",
241 priv->smba + ISMT_GR_ERRINTMSK,
242 readl(priv->smba + ISMT_GR_ERRINTMSK));
243 dev_dbg(dev, " ERRAERMSK : (0x%p)=0x%X\n",
244 priv->smba + ISMT_GR_ERRAERMSK,
245 readl(priv->smba + ISMT_GR_ERRAERMSK));
246 dev_dbg(dev, " ERRSTS... : (0x%p)=0x%X\n",
247 priv->smba + ISMT_GR_ERRSTS,
248 readl(priv->smba + ISMT_GR_ERRSTS));
249 dev_dbg(dev, " ERRINFO.. : (0x%p)=0x%X\n",
250 priv->smba + ISMT_GR_ERRINFO,
251 readl(priv->smba + ISMT_GR_ERRINFO));
255 * ismt_mstr_reg_dump() - dump the iSMT Master Registers
256 * @priv: iSMT private data
258 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
260 struct device *dev = &priv->pci_dev->dev;
262 dev_dbg(dev, "Dump of the iSMT Master Registers\n");
263 dev_dbg(dev, " MDBA..... : (0x%p)=0x%016llX\n",
264 priv->smba + ISMT_MSTR_MDBA,
265 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
266 dev_dbg(dev, " MCTRL.... : (0x%p)=0x%X\n",
267 priv->smba + ISMT_MSTR_MCTRL,
268 readl(priv->smba + ISMT_MSTR_MCTRL));
269 dev_dbg(dev, " MSTS..... : (0x%p)=0x%X\n",
270 priv->smba + ISMT_MSTR_MSTS,
271 readl(priv->smba + ISMT_MSTR_MSTS));
272 dev_dbg(dev, " MDS...... : (0x%p)=0x%X\n",
273 priv->smba + ISMT_MSTR_MDS,
274 readl(priv->smba + ISMT_MSTR_MDS));
275 dev_dbg(dev, " RPOLICY.. : (0x%p)=0x%X\n",
276 priv->smba + ISMT_MSTR_RPOLICY,
277 readl(priv->smba + ISMT_MSTR_RPOLICY));
278 dev_dbg(dev, " SPGT..... : (0x%p)=0x%X\n",
279 priv->smba + ISMT_SPGT,
280 readl(priv->smba + ISMT_SPGT));
284 * ismt_submit_desc() - add a descriptor to the ring
285 * @priv: iSMT private data
287 static void ismt_submit_desc(struct ismt_priv *priv)
289 uint fmhp;
290 uint val;
292 ismt_desc_dump(priv);
293 ismt_gen_reg_dump(priv);
294 ismt_mstr_reg_dump(priv);
296 /* Set the FMHP (Firmware Master Head Pointer)*/
297 fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
298 val = readl(priv->smba + ISMT_MSTR_MCTRL);
299 writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
300 priv->smba + ISMT_MSTR_MCTRL);
302 /* Set the start bit */
303 val = readl(priv->smba + ISMT_MSTR_MCTRL);
304 writel(val | ISMT_MCTRL_SS,
305 priv->smba + ISMT_MSTR_MCTRL);
309 * ismt_process_desc() - handle the completion of the descriptor
310 * @desc: the iSMT hardware descriptor
311 * @data: data buffer from the upper layer
312 * @priv: ismt_priv struct holding our dma buffer
313 * @size: SMBus transaction type
314 * @read_write: flag to indicate if this is a read or write
316 static int ismt_process_desc(const struct ismt_desc *desc,
317 union i2c_smbus_data *data,
318 struct ismt_priv *priv, int size,
319 char read_write)
321 u8 *dma_buffer = priv->dma_buffer;
323 dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
324 __ismt_desc_dump(&priv->pci_dev->dev, desc);
326 if (desc->status & ISMT_DESC_SCS) {
327 if (read_write == I2C_SMBUS_WRITE &&
328 size != I2C_SMBUS_PROC_CALL)
329 return 0;
331 switch (size) {
332 case I2C_SMBUS_BYTE:
333 case I2C_SMBUS_BYTE_DATA:
334 data->byte = dma_buffer[0];
335 break;
336 case I2C_SMBUS_WORD_DATA:
337 case I2C_SMBUS_PROC_CALL:
338 data->word = dma_buffer[0] | (dma_buffer[1] << 8);
339 break;
340 case I2C_SMBUS_BLOCK_DATA:
341 if (desc->rxbytes != dma_buffer[0] + 1)
342 return -EMSGSIZE;
344 memcpy(data->block, dma_buffer, desc->rxbytes);
345 break;
346 case I2C_SMBUS_I2C_BLOCK_DATA:
347 memcpy(&data->block[1], dma_buffer, desc->rxbytes);
348 data->block[0] = desc->rxbytes;
349 break;
351 return 0;
354 if (likely(desc->status & ISMT_DESC_NAK))
355 return -ENXIO;
357 if (desc->status & ISMT_DESC_CRC)
358 return -EBADMSG;
360 if (desc->status & ISMT_DESC_COL)
361 return -EAGAIN;
363 if (desc->status & ISMT_DESC_LPR)
364 return -EPROTO;
366 if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
367 return -ETIMEDOUT;
369 return -EIO;
373 * ismt_access() - process an SMBus command
374 * @adap: the i2c host adapter
375 * @addr: address of the i2c/SMBus target
376 * @flags: command options
377 * @read_write: read from or write to device
378 * @command: the i2c/SMBus command to issue
379 * @size: SMBus transaction type
380 * @data: read/write data buffer
382 static int ismt_access(struct i2c_adapter *adap, u16 addr,
383 unsigned short flags, char read_write, u8 command,
384 int size, union i2c_smbus_data *data)
386 int ret;
387 unsigned long time_left;
388 dma_addr_t dma_addr = 0; /* address of the data buffer */
389 u8 dma_size = 0;
390 enum dma_data_direction dma_direction = 0;
391 struct ismt_desc *desc;
392 struct ismt_priv *priv = i2c_get_adapdata(adap);
393 struct device *dev = &priv->pci_dev->dev;
395 desc = &priv->hw[priv->head];
397 /* Initialize the DMA buffer */
398 memset(priv->dma_buffer, 0, sizeof(priv->dma_buffer));
400 /* Initialize the descriptor */
401 memset(desc, 0, sizeof(struct ismt_desc));
402 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
404 /* Initialize common control bits */
405 if (likely(pci_dev_msi_enabled(priv->pci_dev)))
406 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
407 else
408 desc->control = ISMT_DESC_FAIR;
410 if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
411 && (size != I2C_SMBUS_I2C_BLOCK_DATA))
412 desc->control |= ISMT_DESC_PEC;
414 switch (size) {
415 case I2C_SMBUS_QUICK:
416 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
417 break;
419 case I2C_SMBUS_BYTE:
420 if (read_write == I2C_SMBUS_WRITE) {
422 * Send Byte
423 * The command field contains the write data
425 dev_dbg(dev, "I2C_SMBUS_BYTE: WRITE\n");
426 desc->control |= ISMT_DESC_CWRL;
427 desc->wr_len_cmd = command;
428 } else {
429 /* Receive Byte */
430 dev_dbg(dev, "I2C_SMBUS_BYTE: READ\n");
431 dma_size = 1;
432 dma_direction = DMA_FROM_DEVICE;
433 desc->rd_len = 1;
435 break;
437 case I2C_SMBUS_BYTE_DATA:
438 if (read_write == I2C_SMBUS_WRITE) {
440 * Write Byte
441 * Command plus 1 data byte
443 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
444 desc->wr_len_cmd = 2;
445 dma_size = 2;
446 dma_direction = DMA_TO_DEVICE;
447 priv->dma_buffer[0] = command;
448 priv->dma_buffer[1] = data->byte;
449 } else {
450 /* Read Byte */
451 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: READ\n");
452 desc->control |= ISMT_DESC_CWRL;
453 desc->wr_len_cmd = command;
454 desc->rd_len = 1;
455 dma_size = 1;
456 dma_direction = DMA_FROM_DEVICE;
458 break;
460 case I2C_SMBUS_WORD_DATA:
461 if (read_write == I2C_SMBUS_WRITE) {
462 /* Write Word */
463 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
464 desc->wr_len_cmd = 3;
465 dma_size = 3;
466 dma_direction = DMA_TO_DEVICE;
467 priv->dma_buffer[0] = command;
468 priv->dma_buffer[1] = data->word & 0xff;
469 priv->dma_buffer[2] = data->word >> 8;
470 } else {
471 /* Read Word */
472 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: READ\n");
473 desc->wr_len_cmd = command;
474 desc->control |= ISMT_DESC_CWRL;
475 desc->rd_len = 2;
476 dma_size = 2;
477 dma_direction = DMA_FROM_DEVICE;
479 break;
481 case I2C_SMBUS_PROC_CALL:
482 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
483 desc->wr_len_cmd = 3;
484 desc->rd_len = 2;
485 dma_size = 3;
486 dma_direction = DMA_BIDIRECTIONAL;
487 priv->dma_buffer[0] = command;
488 priv->dma_buffer[1] = data->word & 0xff;
489 priv->dma_buffer[2] = data->word >> 8;
490 break;
492 case I2C_SMBUS_BLOCK_DATA:
493 if (read_write == I2C_SMBUS_WRITE) {
494 /* Block Write */
495 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n");
496 dma_size = data->block[0] + 1;
497 dma_direction = DMA_TO_DEVICE;
498 desc->wr_len_cmd = dma_size;
499 desc->control |= ISMT_DESC_BLK;
500 priv->dma_buffer[0] = command;
501 memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
502 } else {
503 /* Block Read */
504 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
505 dma_size = I2C_SMBUS_BLOCK_MAX;
506 dma_direction = DMA_FROM_DEVICE;
507 desc->rd_len = dma_size;
508 desc->wr_len_cmd = command;
509 desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
511 break;
513 case I2C_SMBUS_I2C_BLOCK_DATA:
514 /* Make sure the length is valid */
515 if (data->block[0] < 1)
516 data->block[0] = 1;
518 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
519 data->block[0] = I2C_SMBUS_BLOCK_MAX;
521 if (read_write == I2C_SMBUS_WRITE) {
522 /* i2c Block Write */
523 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: WRITE\n");
524 dma_size = data->block[0] + 1;
525 dma_direction = DMA_TO_DEVICE;
526 desc->wr_len_cmd = dma_size;
527 desc->control |= ISMT_DESC_I2C;
528 priv->dma_buffer[0] = command;
529 memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
530 } else {
531 /* i2c Block Read */
532 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: READ\n");
533 dma_size = data->block[0];
534 dma_direction = DMA_FROM_DEVICE;
535 desc->rd_len = dma_size;
536 desc->wr_len_cmd = command;
537 desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
539 * Per the "Table 15-15. I2C Commands",
540 * in the External Design Specification (EDS),
541 * (Document Number: 508084, Revision: 2.0),
542 * the _rw bit must be 0
544 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
546 break;
548 default:
549 dev_err(dev, "Unsupported transaction %d\n",
550 size);
551 return -EOPNOTSUPP;
554 /* map the data buffer */
555 if (dma_size != 0) {
556 dev_dbg(dev, " dev=%p\n", dev);
557 dev_dbg(dev, " data=%p\n", data);
558 dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
559 dev_dbg(dev, " dma_size=%d\n", dma_size);
560 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
562 dma_addr = dma_map_single(dev,
563 priv->dma_buffer,
564 dma_size,
565 dma_direction);
567 if (dma_mapping_error(dev, dma_addr)) {
568 dev_err(dev, "Error in mapping dma buffer %p\n",
569 priv->dma_buffer);
570 return -EIO;
573 dev_dbg(dev, " dma_addr = 0x%016llX\n",
574 (unsigned long long)dma_addr);
576 desc->dptr_low = lower_32_bits(dma_addr);
577 desc->dptr_high = upper_32_bits(dma_addr);
580 reinit_completion(&priv->cmp);
582 /* Add the descriptor */
583 ismt_submit_desc(priv);
585 /* Now we wait for interrupt completion, 1s */
586 time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
588 /* unmap the data buffer */
589 if (dma_size != 0)
590 dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
592 if (unlikely(!time_left)) {
593 dev_err(dev, "completion wait timed out\n");
594 ret = -ETIMEDOUT;
595 goto out;
598 /* do any post processing of the descriptor here */
599 ret = ismt_process_desc(desc, data, priv, size, read_write);
601 out:
602 /* Update the ring pointer */
603 priv->head++;
604 priv->head %= ISMT_DESC_ENTRIES;
606 return ret;
610 * ismt_func() - report which i2c commands are supported by this adapter
611 * @adap: the i2c host adapter
613 static u32 ismt_func(struct i2c_adapter *adap)
615 return I2C_FUNC_SMBUS_QUICK |
616 I2C_FUNC_SMBUS_BYTE |
617 I2C_FUNC_SMBUS_BYTE_DATA |
618 I2C_FUNC_SMBUS_WORD_DATA |
619 I2C_FUNC_SMBUS_PROC_CALL |
620 I2C_FUNC_SMBUS_BLOCK_DATA |
621 I2C_FUNC_SMBUS_I2C_BLOCK |
622 I2C_FUNC_SMBUS_PEC;
626 * smbus_algorithm - the adapter algorithm and supported functionality
627 * @smbus_xfer: the adapter algorithm
628 * @functionality: functionality supported by the adapter
630 static const struct i2c_algorithm smbus_algorithm = {
631 .smbus_xfer = ismt_access,
632 .functionality = ismt_func,
636 * ismt_handle_isr() - interrupt handler bottom half
637 * @priv: iSMT private data
639 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
641 complete(&priv->cmp);
643 return IRQ_HANDLED;
648 * ismt_do_interrupt() - IRQ interrupt handler
649 * @vec: interrupt vector
650 * @data: iSMT private data
652 static irqreturn_t ismt_do_interrupt(int vec, void *data)
654 u32 val;
655 struct ismt_priv *priv = data;
658 * check to see it's our interrupt, return IRQ_NONE if not ours
659 * since we are sharing interrupt
661 val = readl(priv->smba + ISMT_MSTR_MSTS);
663 if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
664 return IRQ_NONE;
665 else
666 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
667 priv->smba + ISMT_MSTR_MSTS);
669 return ismt_handle_isr(priv);
673 * ismt_do_msi_interrupt() - MSI interrupt handler
674 * @vec: interrupt vector
675 * @data: iSMT private data
677 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
679 return ismt_handle_isr(data);
683 * ismt_hw_init() - initialize the iSMT hardware
684 * @priv: iSMT private data
686 static void ismt_hw_init(struct ismt_priv *priv)
688 u32 val;
689 struct device *dev = &priv->pci_dev->dev;
691 /* initialize the Master Descriptor Base Address (MDBA) */
692 writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
694 /* initialize the Master Control Register (MCTRL) */
695 writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
697 /* initialize the Master Status Register (MSTS) */
698 writel(0, priv->smba + ISMT_MSTR_MSTS);
700 /* initialize the Master Descriptor Size (MDS) */
701 val = readl(priv->smba + ISMT_MSTR_MDS);
702 writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
703 priv->smba + ISMT_MSTR_MDS);
706 * Set the SMBus speed (could use this for slow HW debuggers)
709 val = readl(priv->smba + ISMT_SPGT);
711 switch (bus_speed) {
712 case 0:
713 break;
715 case 80:
716 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
717 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
718 priv->smba + ISMT_SPGT);
719 break;
721 case 100:
722 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
723 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
724 priv->smba + ISMT_SPGT);
725 break;
727 case 400:
728 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
729 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
730 priv->smba + ISMT_SPGT);
731 break;
733 case 1000:
734 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
735 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
736 priv->smba + ISMT_SPGT);
737 break;
739 default:
740 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
741 break;
744 val = readl(priv->smba + ISMT_SPGT);
746 switch (val & ISMT_SPGT_SPD_MASK) {
747 case ISMT_SPGT_SPD_80K:
748 bus_speed = 80;
749 break;
750 case ISMT_SPGT_SPD_100K:
751 bus_speed = 100;
752 break;
753 case ISMT_SPGT_SPD_400K:
754 bus_speed = 400;
755 break;
756 case ISMT_SPGT_SPD_1M:
757 bus_speed = 1000;
758 break;
760 dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
764 * ismt_dev_init() - initialize the iSMT data structures
765 * @priv: iSMT private data
767 static int ismt_dev_init(struct ismt_priv *priv)
769 /* allocate memory for the descriptor */
770 priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
771 (ISMT_DESC_ENTRIES
772 * sizeof(struct ismt_desc)),
773 &priv->io_rng_dma,
774 GFP_KERNEL);
775 if (!priv->hw)
776 return -ENOMEM;
778 memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
780 priv->head = 0;
781 init_completion(&priv->cmp);
783 return 0;
787 * ismt_int_init() - initialize interrupts
788 * @priv: iSMT private data
790 static int ismt_int_init(struct ismt_priv *priv)
792 int err;
794 /* Try using MSI interrupts */
795 err = pci_enable_msi(priv->pci_dev);
796 if (err)
797 goto intx;
799 err = devm_request_irq(&priv->pci_dev->dev,
800 priv->pci_dev->irq,
801 ismt_do_msi_interrupt,
803 "ismt-msi",
804 priv);
805 if (err) {
806 pci_disable_msi(priv->pci_dev);
807 goto intx;
810 return 0;
812 /* Try using legacy interrupts */
813 intx:
814 dev_warn(&priv->pci_dev->dev,
815 "Unable to use MSI interrupts, falling back to legacy\n");
817 err = devm_request_irq(&priv->pci_dev->dev,
818 priv->pci_dev->irq,
819 ismt_do_interrupt,
820 IRQF_SHARED,
821 "ismt-intx",
822 priv);
823 if (err) {
824 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
825 return err;
828 return 0;
831 static struct pci_driver ismt_driver;
834 * ismt_probe() - probe for iSMT devices
835 * @pdev: PCI-Express device
836 * @id: PCI-Express device ID
838 static int
839 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
841 int err;
842 struct ismt_priv *priv;
843 unsigned long start, len;
845 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
846 if (!priv)
847 return -ENOMEM;
849 pci_set_drvdata(pdev, priv);
851 i2c_set_adapdata(&priv->adapter, priv);
852 priv->adapter.owner = THIS_MODULE;
853 priv->adapter.class = I2C_CLASS_HWMON;
854 priv->adapter.algo = &smbus_algorithm;
855 priv->adapter.dev.parent = &pdev->dev;
856 ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
857 priv->adapter.retries = ISMT_MAX_RETRIES;
859 priv->pci_dev = pdev;
861 err = pcim_enable_device(pdev);
862 if (err) {
863 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
864 err);
865 return err;
868 /* enable bus mastering */
869 pci_set_master(pdev);
871 /* Determine the address of the SMBus area */
872 start = pci_resource_start(pdev, SMBBAR);
873 len = pci_resource_len(pdev, SMBBAR);
874 if (!start || !len) {
875 dev_err(&pdev->dev,
876 "SMBus base address uninitialized, upgrade BIOS\n");
877 return -ENODEV;
880 snprintf(priv->adapter.name, sizeof(priv->adapter.name),
881 "SMBus iSMT adapter at %lx", start);
883 dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
884 dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
886 err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
887 if (err) {
888 dev_err(&pdev->dev, "ACPI resource conflict!\n");
889 return err;
892 err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
893 if (err) {
894 dev_err(&pdev->dev,
895 "Failed to request SMBus region 0x%lx-0x%lx\n",
896 start, start + len);
897 return err;
900 priv->smba = pcim_iomap(pdev, SMBBAR, len);
901 if (!priv->smba) {
902 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
903 return -ENODEV;
906 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
907 (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
908 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
909 (pci_set_consistent_dma_mask(pdev,
910 DMA_BIT_MASK(32)) != 0)) {
911 dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
912 pdev);
913 return -ENODEV;
917 err = ismt_dev_init(priv);
918 if (err)
919 return err;
921 ismt_hw_init(priv);
923 err = ismt_int_init(priv);
924 if (err)
925 return err;
927 err = i2c_add_adapter(&priv->adapter);
928 if (err) {
929 dev_err(&pdev->dev, "Failed to add SMBus iSMT adapter\n");
930 return -ENODEV;
932 return 0;
936 * ismt_remove() - release driver resources
937 * @pdev: PCI-Express device
939 static void ismt_remove(struct pci_dev *pdev)
941 struct ismt_priv *priv = pci_get_drvdata(pdev);
943 i2c_del_adapter(&priv->adapter);
946 static struct pci_driver ismt_driver = {
947 .name = "ismt_smbus",
948 .id_table = ismt_ids,
949 .probe = ismt_probe,
950 .remove = ismt_remove,
953 module_pci_driver(ismt_driver);
955 MODULE_LICENSE("Dual BSD/GPL");
956 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
957 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");