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 * The full GNU General Public License is included in this distribution
18 * in the file called LICENSE.GPL.
19 *
20 * BSD LICENSE
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 *
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.
35 *
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.
47 */
48
49 /*
50 * Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
51 * S12xx Product Family.
52 *
53 * Features supported by this driver:
54 * Hardware PEC yes
55 * Block buffer yes
56 * Block process call transaction yes
57 * Slave mode no
58 */
59
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>
69
70 #include <linux/io-64-nonatomic-lo-hi.h>
71
72 /* PCI Address Constants */
73 #define SMBBAR 0
74
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_CDF_SMT 0x18ac
79 #define PCI_DEVICE_ID_INTEL_DNV_SMT 0x19ac
80 #define PCI_DEVICE_ID_INTEL_EBG_SMT 0x1bff
81 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT 0x1f15
82
83 #define ISMT_DESC_ENTRIES 2 /* number of descriptor entries */
84 #define ISMT_MAX_RETRIES 3 /* number of SMBus retries to attempt */
85 #define ISMT_LOG_ENTRIES 3 /* number of interrupt cause log entries */
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 (0x2U << 30) /* 400 kHz */
150 #define ISMT_SPGT_SPD_1M (0x3U << 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 */
157 struct 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
170 struct ismt_priv {
171 struct i2c_adapter adapter;
172 void __iomem *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 buffer[I2C_SMBUS_BLOCK_MAX + 16]; /* temp R/W data buffer */
179 dma_addr_t log_dma;
180 u32 *log;
181 };
182
183 static const struct pci_device_id ismt_ids[] = {
184 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
185 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
186 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CDF_SMT) },
187 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_DNV_SMT) },
188 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_EBG_SMT) },
189 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
190 { 0, }
191 };
192
193 MODULE_DEVICE_TABLE(pci, ismt_ids);
194
195 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
196 static unsigned int bus_speed;
197 module_param(bus_speed, uint, S_IRUGO);
198 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
199
200 /**
201 * __ismt_desc_dump() - dump the contents of a specific descriptor
202 * @dev: the iSMT device
203 * @desc: the iSMT hardware descriptor
204 */
__ismt_desc_dump(struct device * dev,const struct ismt_desc * desc)205 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
206 {
207
208 dev_dbg(dev, "Descriptor struct: %p\n", desc);
209 dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
210 dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
211 dev_dbg(dev, "\trd_len= 0x%02X\n", desc->rd_len);
212 dev_dbg(dev, "\tcontrol= 0x%02X\n", desc->control);
213 dev_dbg(dev, "\tstatus= 0x%02X\n", desc->status);
214 dev_dbg(dev, "\tretry= 0x%02X\n", desc->retry);
215 dev_dbg(dev, "\trxbytes= 0x%02X\n", desc->rxbytes);
216 dev_dbg(dev, "\ttxbytes= 0x%02X\n", desc->txbytes);
217 dev_dbg(dev, "\tdptr_low= 0x%08X\n", desc->dptr_low);
218 dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
219 }
220 /**
221 * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
222 * @priv: iSMT private data
223 */
ismt_desc_dump(struct ismt_priv * priv)224 static void ismt_desc_dump(struct ismt_priv *priv)
225 {
226 struct device *dev = &priv->pci_dev->dev;
227 struct ismt_desc *desc = &priv->hw[priv->head];
228
229 dev_dbg(dev, "Dump of the descriptor struct: 0x%X\n", priv->head);
230 __ismt_desc_dump(dev, desc);
231 }
232
233 /**
234 * ismt_gen_reg_dump() - dump the iSMT General Registers
235 * @priv: iSMT private data
236 */
ismt_gen_reg_dump(struct ismt_priv * priv)237 static void ismt_gen_reg_dump(struct ismt_priv *priv)
238 {
239 struct device *dev = &priv->pci_dev->dev;
240
241 dev_dbg(dev, "Dump of the iSMT General Registers\n");
242 dev_dbg(dev, " GCTRL.... : (0x%p)=0x%X\n",
243 priv->smba + ISMT_GR_GCTRL,
244 readl(priv->smba + ISMT_GR_GCTRL));
245 dev_dbg(dev, " SMTICL... : (0x%p)=0x%016llX\n",
246 priv->smba + ISMT_GR_SMTICL,
247 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
248 dev_dbg(dev, " ERRINTMSK : (0x%p)=0x%X\n",
249 priv->smba + ISMT_GR_ERRINTMSK,
250 readl(priv->smba + ISMT_GR_ERRINTMSK));
251 dev_dbg(dev, " ERRAERMSK : (0x%p)=0x%X\n",
252 priv->smba + ISMT_GR_ERRAERMSK,
253 readl(priv->smba + ISMT_GR_ERRAERMSK));
254 dev_dbg(dev, " ERRSTS... : (0x%p)=0x%X\n",
255 priv->smba + ISMT_GR_ERRSTS,
256 readl(priv->smba + ISMT_GR_ERRSTS));
257 dev_dbg(dev, " ERRINFO.. : (0x%p)=0x%X\n",
258 priv->smba + ISMT_GR_ERRINFO,
259 readl(priv->smba + ISMT_GR_ERRINFO));
260 }
261
262 /**
263 * ismt_mstr_reg_dump() - dump the iSMT Master Registers
264 * @priv: iSMT private data
265 */
ismt_mstr_reg_dump(struct ismt_priv * priv)266 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
267 {
268 struct device *dev = &priv->pci_dev->dev;
269
270 dev_dbg(dev, "Dump of the iSMT Master Registers\n");
271 dev_dbg(dev, " MDBA..... : (0x%p)=0x%016llX\n",
272 priv->smba + ISMT_MSTR_MDBA,
273 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
274 dev_dbg(dev, " MCTRL.... : (0x%p)=0x%X\n",
275 priv->smba + ISMT_MSTR_MCTRL,
276 readl(priv->smba + ISMT_MSTR_MCTRL));
277 dev_dbg(dev, " MSTS..... : (0x%p)=0x%X\n",
278 priv->smba + ISMT_MSTR_MSTS,
279 readl(priv->smba + ISMT_MSTR_MSTS));
280 dev_dbg(dev, " MDS...... : (0x%p)=0x%X\n",
281 priv->smba + ISMT_MSTR_MDS,
282 readl(priv->smba + ISMT_MSTR_MDS));
283 dev_dbg(dev, " RPOLICY.. : (0x%p)=0x%X\n",
284 priv->smba + ISMT_MSTR_RPOLICY,
285 readl(priv->smba + ISMT_MSTR_RPOLICY));
286 dev_dbg(dev, " SPGT..... : (0x%p)=0x%X\n",
287 priv->smba + ISMT_SPGT,
288 readl(priv->smba + ISMT_SPGT));
289 }
290
291 /**
292 * ismt_submit_desc() - add a descriptor to the ring
293 * @priv: iSMT private data
294 */
ismt_submit_desc(struct ismt_priv * priv)295 static void ismt_submit_desc(struct ismt_priv *priv)
296 {
297 uint fmhp;
298 uint val;
299
300 ismt_desc_dump(priv);
301 ismt_gen_reg_dump(priv);
302 ismt_mstr_reg_dump(priv);
303
304 /* Set the FMHP (Firmware Master Head Pointer)*/
305 fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
306 val = readl(priv->smba + ISMT_MSTR_MCTRL);
307 writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
308 priv->smba + ISMT_MSTR_MCTRL);
309
310 /* Set the start bit */
311 val = readl(priv->smba + ISMT_MSTR_MCTRL);
312 writel(val | ISMT_MCTRL_SS,
313 priv->smba + ISMT_MSTR_MCTRL);
314 }
315
316 /**
317 * ismt_process_desc() - handle the completion of the descriptor
318 * @desc: the iSMT hardware descriptor
319 * @data: data buffer from the upper layer
320 * @priv: ismt_priv struct holding our dma buffer
321 * @size: SMBus transaction type
322 * @read_write: flag to indicate if this is a read or write
323 */
ismt_process_desc(const struct ismt_desc * desc,union i2c_smbus_data * data,struct ismt_priv * priv,int size,char read_write)324 static int ismt_process_desc(const struct ismt_desc *desc,
325 union i2c_smbus_data *data,
326 struct ismt_priv *priv, int size,
327 char read_write)
328 {
329 u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
330
331 dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
332 __ismt_desc_dump(&priv->pci_dev->dev, desc);
333 ismt_gen_reg_dump(priv);
334 ismt_mstr_reg_dump(priv);
335
336 if (desc->status & ISMT_DESC_SCS) {
337 if (read_write == I2C_SMBUS_WRITE &&
338 size != I2C_SMBUS_PROC_CALL &&
339 size != I2C_SMBUS_BLOCK_PROC_CALL)
340 return 0;
341
342 switch (size) {
343 case I2C_SMBUS_BYTE:
344 case I2C_SMBUS_BYTE_DATA:
345 data->byte = dma_buffer[0];
346 break;
347 case I2C_SMBUS_WORD_DATA:
348 case I2C_SMBUS_PROC_CALL:
349 data->word = dma_buffer[0] | (dma_buffer[1] << 8);
350 break;
351 case I2C_SMBUS_BLOCK_DATA:
352 case I2C_SMBUS_BLOCK_PROC_CALL:
353 if (desc->rxbytes != dma_buffer[0] + 1)
354 return -EMSGSIZE;
355
356 memcpy(data->block, dma_buffer, desc->rxbytes);
357 break;
358 case I2C_SMBUS_I2C_BLOCK_DATA:
359 memcpy(&data->block[1], dma_buffer, desc->rxbytes);
360 data->block[0] = desc->rxbytes;
361 break;
362 }
363 return 0;
364 }
365
366 if (likely(desc->status & ISMT_DESC_NAK))
367 return -ENXIO;
368
369 if (desc->status & ISMT_DESC_CRC)
370 return -EBADMSG;
371
372 if (desc->status & ISMT_DESC_COL)
373 return -EAGAIN;
374
375 if (desc->status & ISMT_DESC_LPR)
376 return -EPROTO;
377
378 if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
379 return -ETIMEDOUT;
380
381 return -EIO;
382 }
383
384 /**
385 * ismt_access() - process an SMBus command
386 * @adap: the i2c host adapter
387 * @addr: address of the i2c/SMBus target
388 * @flags: command options
389 * @read_write: read from or write to device
390 * @command: the i2c/SMBus command to issue
391 * @size: SMBus transaction type
392 * @data: read/write data buffer
393 */
ismt_access(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)394 static int ismt_access(struct i2c_adapter *adap, u16 addr,
395 unsigned short flags, char read_write, u8 command,
396 int size, union i2c_smbus_data *data)
397 {
398 int ret;
399 unsigned long time_left;
400 dma_addr_t dma_addr = 0; /* address of the data buffer */
401 u8 dma_size = 0;
402 enum dma_data_direction dma_direction = 0;
403 struct ismt_desc *desc;
404 struct ismt_priv *priv = i2c_get_adapdata(adap);
405 struct device *dev = &priv->pci_dev->dev;
406 u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
407
408 desc = &priv->hw[priv->head];
409
410 /* Initialize the DMA buffer */
411 memset(priv->buffer, 0, sizeof(priv->buffer));
412
413 /* Initialize the descriptor */
414 memset(desc, 0, sizeof(struct ismt_desc));
415 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
416
417 /* Always clear the log entries */
418 memset(priv->log, 0, ISMT_LOG_ENTRIES * sizeof(u32));
419
420 /* Initialize common control bits */
421 if (likely(pci_dev_msi_enabled(priv->pci_dev)))
422 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
423 else
424 desc->control = ISMT_DESC_FAIR;
425
426 if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
427 && (size != I2C_SMBUS_I2C_BLOCK_DATA))
428 desc->control |= ISMT_DESC_PEC;
429
430 switch (size) {
431 case I2C_SMBUS_QUICK:
432 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
433 break;
434
435 case I2C_SMBUS_BYTE:
436 if (read_write == I2C_SMBUS_WRITE) {
437 /*
438 * Send Byte
439 * The command field contains the write data
440 */
441 dev_dbg(dev, "I2C_SMBUS_BYTE: WRITE\n");
442 desc->control |= ISMT_DESC_CWRL;
443 desc->wr_len_cmd = command;
444 } else {
445 /* Receive Byte */
446 dev_dbg(dev, "I2C_SMBUS_BYTE: READ\n");
447 dma_size = 1;
448 dma_direction = DMA_FROM_DEVICE;
449 desc->rd_len = 1;
450 }
451 break;
452
453 case I2C_SMBUS_BYTE_DATA:
454 if (read_write == I2C_SMBUS_WRITE) {
455 /*
456 * Write Byte
457 * Command plus 1 data byte
458 */
459 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
460 desc->wr_len_cmd = 2;
461 dma_size = 2;
462 dma_direction = DMA_TO_DEVICE;
463 dma_buffer[0] = command;
464 dma_buffer[1] = data->byte;
465 } else {
466 /* Read Byte */
467 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: READ\n");
468 desc->control |= ISMT_DESC_CWRL;
469 desc->wr_len_cmd = command;
470 desc->rd_len = 1;
471 dma_size = 1;
472 dma_direction = DMA_FROM_DEVICE;
473 }
474 break;
475
476 case I2C_SMBUS_WORD_DATA:
477 if (read_write == I2C_SMBUS_WRITE) {
478 /* Write Word */
479 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
480 desc->wr_len_cmd = 3;
481 dma_size = 3;
482 dma_direction = DMA_TO_DEVICE;
483 dma_buffer[0] = command;
484 dma_buffer[1] = data->word & 0xff;
485 dma_buffer[2] = data->word >> 8;
486 } else {
487 /* Read Word */
488 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: READ\n");
489 desc->wr_len_cmd = command;
490 desc->control |= ISMT_DESC_CWRL;
491 desc->rd_len = 2;
492 dma_size = 2;
493 dma_direction = DMA_FROM_DEVICE;
494 }
495 break;
496
497 case I2C_SMBUS_PROC_CALL:
498 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
499 desc->wr_len_cmd = 3;
500 desc->rd_len = 2;
501 dma_size = 3;
502 dma_direction = DMA_BIDIRECTIONAL;
503 dma_buffer[0] = command;
504 dma_buffer[1] = data->word & 0xff;
505 dma_buffer[2] = data->word >> 8;
506 break;
507
508 case I2C_SMBUS_BLOCK_DATA:
509 if (read_write == I2C_SMBUS_WRITE) {
510 /* Block Write */
511 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n");
512 if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
513 return -EINVAL;
514
515 dma_size = data->block[0] + 1;
516 dma_direction = DMA_TO_DEVICE;
517 desc->wr_len_cmd = dma_size;
518 desc->control |= ISMT_DESC_BLK;
519 dma_buffer[0] = command;
520 memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
521 } else {
522 /* Block Read */
523 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
524 dma_size = I2C_SMBUS_BLOCK_MAX;
525 dma_direction = DMA_FROM_DEVICE;
526 desc->rd_len = dma_size;
527 desc->wr_len_cmd = command;
528 desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
529 }
530 break;
531
532 case I2C_SMBUS_BLOCK_PROC_CALL:
533 dev_dbg(dev, "I2C_SMBUS_BLOCK_PROC_CALL\n");
534 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
535 return -EINVAL;
536
537 dma_size = I2C_SMBUS_BLOCK_MAX;
538 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 1);
539 desc->wr_len_cmd = data->block[0] + 1;
540 desc->rd_len = dma_size;
541 desc->control |= ISMT_DESC_BLK;
542 dma_direction = DMA_BIDIRECTIONAL;
543 dma_buffer[0] = command;
544 memcpy(&dma_buffer[1], &data->block[1], data->block[0]);
545 break;
546
547 case I2C_SMBUS_I2C_BLOCK_DATA:
548 /* Make sure the length is valid */
549 if (data->block[0] < 1)
550 data->block[0] = 1;
551
552 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
553 data->block[0] = I2C_SMBUS_BLOCK_MAX;
554
555 if (read_write == I2C_SMBUS_WRITE) {
556 /* i2c Block Write */
557 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: WRITE\n");
558 dma_size = data->block[0] + 1;
559 dma_direction = DMA_TO_DEVICE;
560 desc->wr_len_cmd = dma_size;
561 desc->control |= ISMT_DESC_I2C;
562 dma_buffer[0] = command;
563 memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
564 } else {
565 /* i2c Block Read */
566 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: READ\n");
567 dma_size = data->block[0];
568 dma_direction = DMA_FROM_DEVICE;
569 desc->rd_len = dma_size;
570 desc->wr_len_cmd = command;
571 desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
572 /*
573 * Per the "Table 15-15. I2C Commands",
574 * in the External Design Specification (EDS),
575 * (Document Number: 508084, Revision: 2.0),
576 * the _rw bit must be 0
577 */
578 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
579 }
580 break;
581
582 default:
583 dev_err(dev, "Unsupported transaction %d\n",
584 size);
585 return -EOPNOTSUPP;
586 }
587
588 /* map the data buffer */
589 if (dma_size != 0) {
590 dev_dbg(dev, " dev=%p\n", dev);
591 dev_dbg(dev, " data=%p\n", data);
592 dev_dbg(dev, " dma_buffer=%p\n", dma_buffer);
593 dev_dbg(dev, " dma_size=%d\n", dma_size);
594 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
595
596 dma_addr = dma_map_single(dev,
597 dma_buffer,
598 dma_size,
599 dma_direction);
600
601 if (dma_mapping_error(dev, dma_addr)) {
602 dev_err(dev, "Error in mapping dma buffer %p\n",
603 dma_buffer);
604 return -EIO;
605 }
606
607 dev_dbg(dev, " dma_addr = %pad\n", &dma_addr);
608
609 desc->dptr_low = lower_32_bits(dma_addr);
610 desc->dptr_high = upper_32_bits(dma_addr);
611 }
612
613 reinit_completion(&priv->cmp);
614
615 /* Add the descriptor */
616 ismt_submit_desc(priv);
617
618 /* Now we wait for interrupt completion, 1s */
619 time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
620
621 /* unmap the data buffer */
622 if (dma_size != 0)
623 dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
624
625 if (unlikely(!time_left)) {
626 dev_err(dev, "completion wait timed out\n");
627 ret = -ETIMEDOUT;
628 goto out;
629 }
630
631 /* do any post processing of the descriptor here */
632 ret = ismt_process_desc(desc, data, priv, size, read_write);
633
634 out:
635 /* Update the ring pointer */
636 priv->head++;
637 priv->head %= ISMT_DESC_ENTRIES;
638
639 return ret;
640 }
641
642 /**
643 * ismt_func() - report which i2c commands are supported by this adapter
644 * @adap: the i2c host adapter
645 */
ismt_func(struct i2c_adapter * adap)646 static u32 ismt_func(struct i2c_adapter *adap)
647 {
648 return I2C_FUNC_SMBUS_QUICK |
649 I2C_FUNC_SMBUS_BYTE |
650 I2C_FUNC_SMBUS_BYTE_DATA |
651 I2C_FUNC_SMBUS_WORD_DATA |
652 I2C_FUNC_SMBUS_PROC_CALL |
653 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
654 I2C_FUNC_SMBUS_BLOCK_DATA |
655 I2C_FUNC_SMBUS_I2C_BLOCK |
656 I2C_FUNC_SMBUS_PEC;
657 }
658
659 static const struct i2c_algorithm smbus_algorithm = {
660 .smbus_xfer = ismt_access,
661 .functionality = ismt_func,
662 };
663
664 /**
665 * ismt_handle_isr() - interrupt handler bottom half
666 * @priv: iSMT private data
667 */
ismt_handle_isr(struct ismt_priv * priv)668 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
669 {
670 complete(&priv->cmp);
671
672 return IRQ_HANDLED;
673 }
674
675
676 /**
677 * ismt_do_interrupt() - IRQ interrupt handler
678 * @vec: interrupt vector
679 * @data: iSMT private data
680 */
ismt_do_interrupt(int vec,void * data)681 static irqreturn_t ismt_do_interrupt(int vec, void *data)
682 {
683 u32 val;
684 struct ismt_priv *priv = data;
685
686 /*
687 * check to see it's our interrupt, return IRQ_NONE if not ours
688 * since we are sharing interrupt
689 */
690 val = readl(priv->smba + ISMT_MSTR_MSTS);
691
692 if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
693 return IRQ_NONE;
694 else
695 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
696 priv->smba + ISMT_MSTR_MSTS);
697
698 return ismt_handle_isr(priv);
699 }
700
701 /**
702 * ismt_do_msi_interrupt() - MSI interrupt handler
703 * @vec: interrupt vector
704 * @data: iSMT private data
705 */
ismt_do_msi_interrupt(int vec,void * data)706 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
707 {
708 return ismt_handle_isr(data);
709 }
710
711 /**
712 * ismt_hw_init() - initialize the iSMT hardware
713 * @priv: iSMT private data
714 */
ismt_hw_init(struct ismt_priv * priv)715 static void ismt_hw_init(struct ismt_priv *priv)
716 {
717 u32 val;
718 struct device *dev = &priv->pci_dev->dev;
719
720 /* initialize the Master Descriptor Base Address (MDBA) */
721 writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
722
723 writeq(priv->log_dma, priv->smba + ISMT_GR_SMTICL);
724
725 /* initialize the Master Control Register (MCTRL) */
726 writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
727
728 /* initialize the Master Status Register (MSTS) */
729 writel(0, priv->smba + ISMT_MSTR_MSTS);
730
731 /* initialize the Master Descriptor Size (MDS) */
732 val = readl(priv->smba + ISMT_MSTR_MDS);
733 writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
734 priv->smba + ISMT_MSTR_MDS);
735
736 /*
737 * Set the SMBus speed (could use this for slow HW debuggers)
738 */
739
740 val = readl(priv->smba + ISMT_SPGT);
741
742 switch (bus_speed) {
743 case 0:
744 break;
745
746 case 80:
747 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
748 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
749 priv->smba + ISMT_SPGT);
750 break;
751
752 case 100:
753 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
754 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
755 priv->smba + ISMT_SPGT);
756 break;
757
758 case 400:
759 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
760 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
761 priv->smba + ISMT_SPGT);
762 break;
763
764 case 1000:
765 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
766 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
767 priv->smba + ISMT_SPGT);
768 break;
769
770 default:
771 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
772 break;
773 }
774
775 val = readl(priv->smba + ISMT_SPGT);
776
777 switch (val & ISMT_SPGT_SPD_MASK) {
778 case ISMT_SPGT_SPD_80K:
779 bus_speed = 80;
780 break;
781 case ISMT_SPGT_SPD_100K:
782 bus_speed = 100;
783 break;
784 case ISMT_SPGT_SPD_400K:
785 bus_speed = 400;
786 break;
787 case ISMT_SPGT_SPD_1M:
788 bus_speed = 1000;
789 break;
790 }
791 dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
792 }
793
794 /**
795 * ismt_dev_init() - initialize the iSMT data structures
796 * @priv: iSMT private data
797 */
ismt_dev_init(struct ismt_priv * priv)798 static int ismt_dev_init(struct ismt_priv *priv)
799 {
800 /* allocate memory for the descriptor */
801 priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
802 (ISMT_DESC_ENTRIES
803 * sizeof(struct ismt_desc)),
804 &priv->io_rng_dma,
805 GFP_KERNEL);
806 if (!priv->hw)
807 return -ENOMEM;
808
809 priv->head = 0;
810 init_completion(&priv->cmp);
811
812 priv->log = dmam_alloc_coherent(&priv->pci_dev->dev,
813 ISMT_LOG_ENTRIES * sizeof(u32),
814 &priv->log_dma, GFP_KERNEL);
815 if (!priv->log)
816 return -ENOMEM;
817
818 return 0;
819 }
820
821 /**
822 * ismt_int_init() - initialize interrupts
823 * @priv: iSMT private data
824 */
ismt_int_init(struct ismt_priv * priv)825 static int ismt_int_init(struct ismt_priv *priv)
826 {
827 int err;
828
829 /* Try using MSI interrupts */
830 err = pci_enable_msi(priv->pci_dev);
831 if (err)
832 goto intx;
833
834 err = devm_request_irq(&priv->pci_dev->dev,
835 priv->pci_dev->irq,
836 ismt_do_msi_interrupt,
837 0,
838 "ismt-msi",
839 priv);
840 if (err) {
841 pci_disable_msi(priv->pci_dev);
842 goto intx;
843 }
844
845 return 0;
846
847 /* Try using legacy interrupts */
848 intx:
849 dev_warn(&priv->pci_dev->dev,
850 "Unable to use MSI interrupts, falling back to legacy\n");
851
852 err = devm_request_irq(&priv->pci_dev->dev,
853 priv->pci_dev->irq,
854 ismt_do_interrupt,
855 IRQF_SHARED,
856 "ismt-intx",
857 priv);
858 if (err) {
859 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
860 return err;
861 }
862
863 return 0;
864 }
865
866 static struct pci_driver ismt_driver;
867
868 /**
869 * ismt_probe() - probe for iSMT devices
870 * @pdev: PCI-Express device
871 * @id: PCI-Express device ID
872 */
873 static int
ismt_probe(struct pci_dev * pdev,const struct pci_device_id * id)874 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
875 {
876 int err;
877 struct ismt_priv *priv;
878 unsigned long start, len;
879
880 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
881 if (!priv)
882 return -ENOMEM;
883
884 pci_set_drvdata(pdev, priv);
885
886 i2c_set_adapdata(&priv->adapter, priv);
887 priv->adapter.owner = THIS_MODULE;
888 priv->adapter.class = I2C_CLASS_HWMON;
889 priv->adapter.algo = &smbus_algorithm;
890 priv->adapter.dev.parent = &pdev->dev;
891 ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
892 priv->adapter.retries = ISMT_MAX_RETRIES;
893
894 priv->pci_dev = pdev;
895
896 err = pcim_enable_device(pdev);
897 if (err) {
898 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
899 err);
900 return err;
901 }
902
903 /* enable bus mastering */
904 pci_set_master(pdev);
905
906 /* Determine the address of the SMBus area */
907 start = pci_resource_start(pdev, SMBBAR);
908 len = pci_resource_len(pdev, SMBBAR);
909 if (!start || !len) {
910 dev_err(&pdev->dev,
911 "SMBus base address uninitialized, upgrade BIOS\n");
912 return -ENODEV;
913 }
914
915 snprintf(priv->adapter.name, sizeof(priv->adapter.name),
916 "SMBus iSMT adapter at %lx", start);
917
918 dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
919 dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
920
921 err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
922 if (err) {
923 dev_err(&pdev->dev, "ACPI resource conflict!\n");
924 return err;
925 }
926
927 err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
928 if (err) {
929 dev_err(&pdev->dev,
930 "Failed to request SMBus region 0x%lx-0x%lx\n",
931 start, start + len);
932 return err;
933 }
934
935 priv->smba = pcim_iomap(pdev, SMBBAR, len);
936 if (!priv->smba) {
937 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
938 return -ENODEV;
939 }
940
941 err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
942 if (err) {
943 dev_err(&pdev->dev, "dma_set_mask fail\n");
944 return -ENODEV;
945 }
946
947 err = ismt_dev_init(priv);
948 if (err)
949 return err;
950
951 ismt_hw_init(priv);
952
953 err = ismt_int_init(priv);
954 if (err)
955 return err;
956
957 err = i2c_add_adapter(&priv->adapter);
958 if (err)
959 return -ENODEV;
960 return 0;
961 }
962
963 /**
964 * ismt_remove() - release driver resources
965 * @pdev: PCI-Express device
966 */
ismt_remove(struct pci_dev * pdev)967 static void ismt_remove(struct pci_dev *pdev)
968 {
969 struct ismt_priv *priv = pci_get_drvdata(pdev);
970
971 i2c_del_adapter(&priv->adapter);
972 }
973
974 static struct pci_driver ismt_driver = {
975 .name = "ismt_smbus",
976 .id_table = ismt_ids,
977 .probe = ismt_probe,
978 .remove = ismt_remove,
979 };
980
981 module_pci_driver(ismt_driver);
982
983 MODULE_LICENSE("Dual BSD/GPL");
984 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
985 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");
986