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hwrng: core - Don't use a stack buffer in add_early_randomness()
[linux/fpc-iii.git] / drivers / i2c / busses / i2c-ismt.c
blobf573448d2132161d4839a17d11afb1c1f4104188
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 no
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_DNV_SMT 0x19ac
79 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT 0x1f15
80
81 #define ISMT_DESC_ENTRIES 2 /* number of descriptor entries */
82 #define ISMT_MAX_RETRIES 3 /* number of SMBus retries to attempt */
83
84 /* Hardware Descriptor Constants - Control Field */
85 #define ISMT_DESC_CWRL 0x01 /* Command/Write Length */
86 #define ISMT_DESC_BLK 0X04 /* Perform Block Transaction */
87 #define ISMT_DESC_FAIR 0x08 /* Set fairness flag upon successful arbit. */
88 #define ISMT_DESC_PEC 0x10 /* Packet Error Code */
89 #define ISMT_DESC_I2C 0x20 /* I2C Enable */
90 #define ISMT_DESC_INT 0x40 /* Interrupt */
91 #define ISMT_DESC_SOE 0x80 /* Stop On Error */
92
93 /* Hardware Descriptor Constants - Status Field */
94 #define ISMT_DESC_SCS 0x01 /* Success */
95 #define ISMT_DESC_DLTO 0x04 /* Data Low Time Out */
96 #define ISMT_DESC_NAK 0x08 /* NAK Received */
97 #define ISMT_DESC_CRC 0x10 /* CRC Error */
98 #define ISMT_DESC_CLTO 0x20 /* Clock Low Time Out */
99 #define ISMT_DESC_COL 0x40 /* Collisions */
100 #define ISMT_DESC_LPR 0x80 /* Large Packet Received */
101
102 /* Macros */
103 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
104
105 /* iSMT General Register address offsets (SMBBAR + <addr>) */
106 #define ISMT_GR_GCTRL 0x000 /* General Control */
107 #define ISMT_GR_SMTICL 0x008 /* SMT Interrupt Cause Location */
108 #define ISMT_GR_ERRINTMSK 0x010 /* Error Interrupt Mask */
109 #define ISMT_GR_ERRAERMSK 0x014 /* Error AER Mask */
110 #define ISMT_GR_ERRSTS 0x018 /* Error Status */
111 #define ISMT_GR_ERRINFO 0x01c /* Error Information */
112
113 /* iSMT Master Registers */
114 #define ISMT_MSTR_MDBA 0x100 /* Master Descriptor Base Address */
115 #define ISMT_MSTR_MCTRL 0x108 /* Master Control */
116 #define ISMT_MSTR_MSTS 0x10c /* Master Status */
117 #define ISMT_MSTR_MDS 0x110 /* Master Descriptor Size */
118 #define ISMT_MSTR_RPOLICY 0x114 /* Retry Policy */
119
120 /* iSMT Miscellaneous Registers */
121 #define ISMT_SPGT 0x300 /* SMBus PHY Global Timing */
122
123 /* General Control Register (GCTRL) bit definitions */
124 #define ISMT_GCTRL_TRST 0x04 /* Target Reset */
125 #define ISMT_GCTRL_KILL 0x08 /* Kill */
126 #define ISMT_GCTRL_SRST 0x40 /* Soft Reset */
127
128 /* Master Control Register (MCTRL) bit definitions */
129 #define ISMT_MCTRL_SS 0x01 /* Start/Stop */
130 #define ISMT_MCTRL_MEIE 0x10 /* Master Error Interrupt Enable */
131 #define ISMT_MCTRL_FMHP 0x00ff0000 /* Firmware Master Head Ptr (FMHP) */
132
133 /* Master Status Register (MSTS) bit definitions */
134 #define ISMT_MSTS_HMTP 0xff0000 /* HW Master Tail Pointer (HMTP) */
135 #define ISMT_MSTS_MIS 0x20 /* Master Interrupt Status (MIS) */
136 #define ISMT_MSTS_MEIS 0x10 /* Master Error Int Status (MEIS) */
137 #define ISMT_MSTS_IP 0x01 /* In Progress */
138
139 /* Master Descriptor Size (MDS) bit definitions */
140 #define ISMT_MDS_MASK 0xff /* Master Descriptor Size mask (MDS) */
141
142 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
143 #define ISMT_SPGT_SPD_MASK 0xc0000000 /* SMBus Speed mask */
144 #define ISMT_SPGT_SPD_80K 0x00 /* 80 kHz */
145 #define ISMT_SPGT_SPD_100K (0x1 << 30) /* 100 kHz */
146 #define ISMT_SPGT_SPD_400K (0x2 << 30) /* 400 kHz */
147 #define ISMT_SPGT_SPD_1M (0x3 << 30) /* 1 MHz */
148
149
150 /* MSI Control Register (MSICTL) bit definitions */
151 #define ISMT_MSICTL_MSIE 0x01 /* MSI Enable */
152
153 /* iSMT Hardware Descriptor */
154 struct ismt_desc {
155 u8 tgtaddr_rw; /* target address & r/w bit */
156 u8 wr_len_cmd; /* write length in bytes or a command */
157 u8 rd_len; /* read length */
158 u8 control; /* control bits */
159 u8 status; /* status bits */
160 u8 retry; /* collision retry and retry count */
161 u8 rxbytes; /* received bytes */
162 u8 txbytes; /* transmitted bytes */
163 u32 dptr_low; /* lower 32 bit of the data pointer */
164 u32 dptr_high; /* upper 32 bit of the data pointer */
165 } __packed;
166
167 struct ismt_priv {
168 struct i2c_adapter adapter;
169 void __iomem *smba; /* PCI BAR */
170 struct pci_dev *pci_dev;
171 struct ismt_desc *hw; /* descriptor virt base addr */
172 dma_addr_t io_rng_dma; /* descriptor HW base addr */
173 u8 head; /* ring buffer head pointer */
174 struct completion cmp; /* interrupt completion */
175 u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
176 };
177
178 /**
179 * ismt_ids - PCI device IDs supported by this driver
180 */
181 static const struct pci_device_id ismt_ids[] = {
182 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
183 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
184 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_DNV_SMT) },
185 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
186 { 0, }
187 };
188
189 MODULE_DEVICE_TABLE(pci, ismt_ids);
190
191 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
192 static unsigned int bus_speed;
193 module_param(bus_speed, uint, S_IRUGO);
194 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
195
196 /**
197 * __ismt_desc_dump() - dump the contents of a specific descriptor
198 */
199 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
200 {
201
202 dev_dbg(dev, "Descriptor struct: %p\n", desc);
203 dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
204 dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
205 dev_dbg(dev, "\trd_len= 0x%02X\n", desc->rd_len);
206 dev_dbg(dev, "\tcontrol= 0x%02X\n", desc->control);
207 dev_dbg(dev, "\tstatus= 0x%02X\n", desc->status);
208 dev_dbg(dev, "\tretry= 0x%02X\n", desc->retry);
209 dev_dbg(dev, "\trxbytes= 0x%02X\n", desc->rxbytes);
210 dev_dbg(dev, "\ttxbytes= 0x%02X\n", desc->txbytes);
211 dev_dbg(dev, "\tdptr_low= 0x%08X\n", desc->dptr_low);
212 dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
213 }
214 /**
215 * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
216 * @priv: iSMT private data
217 */
218 static void ismt_desc_dump(struct ismt_priv *priv)
219 {
220 struct device *dev = &priv->pci_dev->dev;
221 struct ismt_desc *desc = &priv->hw[priv->head];
222
223 dev_dbg(dev, "Dump of the descriptor struct: 0x%X\n", priv->head);
224 __ismt_desc_dump(dev, desc);
225 }
226
227 /**
228 * ismt_gen_reg_dump() - dump the iSMT General Registers
229 * @priv: iSMT private data
230 */
231 static void ismt_gen_reg_dump(struct ismt_priv *priv)
232 {
233 struct device *dev = &priv->pci_dev->dev;
234
235 dev_dbg(dev, "Dump of the iSMT General Registers\n");
236 dev_dbg(dev, " GCTRL.... : (0x%p)=0x%X\n",
237 priv->smba + ISMT_GR_GCTRL,
238 readl(priv->smba + ISMT_GR_GCTRL));
239 dev_dbg(dev, " SMTICL... : (0x%p)=0x%016llX\n",
240 priv->smba + ISMT_GR_SMTICL,
241 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
242 dev_dbg(dev, " ERRINTMSK : (0x%p)=0x%X\n",
243 priv->smba + ISMT_GR_ERRINTMSK,
244 readl(priv->smba + ISMT_GR_ERRINTMSK));
245 dev_dbg(dev, " ERRAERMSK : (0x%p)=0x%X\n",
246 priv->smba + ISMT_GR_ERRAERMSK,
247 readl(priv->smba + ISMT_GR_ERRAERMSK));
248 dev_dbg(dev, " ERRSTS... : (0x%p)=0x%X\n",
249 priv->smba + ISMT_GR_ERRSTS,
250 readl(priv->smba + ISMT_GR_ERRSTS));
251 dev_dbg(dev, " ERRINFO.. : (0x%p)=0x%X\n",
252 priv->smba + ISMT_GR_ERRINFO,
253 readl(priv->smba + ISMT_GR_ERRINFO));
254 }
255
256 /**
257 * ismt_mstr_reg_dump() - dump the iSMT Master Registers
258 * @priv: iSMT private data
259 */
260 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
261 {
262 struct device *dev = &priv->pci_dev->dev;
263
264 dev_dbg(dev, "Dump of the iSMT Master Registers\n");
265 dev_dbg(dev, " MDBA..... : (0x%p)=0x%016llX\n",
266 priv->smba + ISMT_MSTR_MDBA,
267 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
268 dev_dbg(dev, " MCTRL.... : (0x%p)=0x%X\n",
269 priv->smba + ISMT_MSTR_MCTRL,
270 readl(priv->smba + ISMT_MSTR_MCTRL));
271 dev_dbg(dev, " MSTS..... : (0x%p)=0x%X\n",
272 priv->smba + ISMT_MSTR_MSTS,
273 readl(priv->smba + ISMT_MSTR_MSTS));
274 dev_dbg(dev, " MDS...... : (0x%p)=0x%X\n",
275 priv->smba + ISMT_MSTR_MDS,
276 readl(priv->smba + ISMT_MSTR_MDS));
277 dev_dbg(dev, " RPOLICY.. : (0x%p)=0x%X\n",
278 priv->smba + ISMT_MSTR_RPOLICY,
279 readl(priv->smba + ISMT_MSTR_RPOLICY));
280 dev_dbg(dev, " SPGT..... : (0x%p)=0x%X\n",
281 priv->smba + ISMT_SPGT,
282 readl(priv->smba + ISMT_SPGT));
283 }
284
285 /**
286 * ismt_submit_desc() - add a descriptor to the ring
287 * @priv: iSMT private data
288 */
289 static void ismt_submit_desc(struct ismt_priv *priv)
290 {
291 uint fmhp;
292 uint val;
293
294 ismt_desc_dump(priv);
295 ismt_gen_reg_dump(priv);
296 ismt_mstr_reg_dump(priv);
297
298 /* Set the FMHP (Firmware Master Head Pointer)*/
299 fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
300 val = readl(priv->smba + ISMT_MSTR_MCTRL);
301 writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
302 priv->smba + ISMT_MSTR_MCTRL);
303
304 /* Set the start bit */
305 val = readl(priv->smba + ISMT_MSTR_MCTRL);
306 writel(val | ISMT_MCTRL_SS,
307 priv->smba + ISMT_MSTR_MCTRL);
308 }
309
310 /**
311 * ismt_process_desc() - handle the completion of the descriptor
312 * @desc: the iSMT hardware descriptor
313 * @data: data buffer from the upper layer
314 * @priv: ismt_priv struct holding our dma buffer
315 * @size: SMBus transaction type
316 * @read_write: flag to indicate if this is a read or write
317 */
318 static int ismt_process_desc(const struct ismt_desc *desc,
319 union i2c_smbus_data *data,
320 struct ismt_priv *priv, int size,
321 char read_write)
322 {
323 u8 *dma_buffer = priv->dma_buffer;
324
325 dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
326 __ismt_desc_dump(&priv->pci_dev->dev, desc);
327
328 if (desc->status & ISMT_DESC_SCS) {
329 if (read_write == I2C_SMBUS_WRITE &&
330 size != I2C_SMBUS_PROC_CALL)
331 return 0;
332
333 switch (size) {
334 case I2C_SMBUS_BYTE:
335 case I2C_SMBUS_BYTE_DATA:
336 data->byte = dma_buffer[0];
337 break;
338 case I2C_SMBUS_WORD_DATA:
339 case I2C_SMBUS_PROC_CALL:
340 data->word = dma_buffer[0] | (dma_buffer[1] << 8);
341 break;
342 case I2C_SMBUS_BLOCK_DATA:
343 case I2C_SMBUS_I2C_BLOCK_DATA:
344 memcpy(&data->block[1], dma_buffer, desc->rxbytes);
345 data->block[0] = desc->rxbytes;
346 break;
347 }
348 return 0;
349 }
350
351 if (likely(desc->status & ISMT_DESC_NAK))
352 return -ENXIO;
353
354 if (desc->status & ISMT_DESC_CRC)
355 return -EBADMSG;
356
357 if (desc->status & ISMT_DESC_COL)
358 return -EAGAIN;
359
360 if (desc->status & ISMT_DESC_LPR)
361 return -EPROTO;
362
363 if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
364 return -ETIMEDOUT;
365
366 return -EIO;
367 }
368
369 /**
370 * ismt_access() - process an SMBus command
371 * @adap: the i2c host adapter
372 * @addr: address of the i2c/SMBus target
373 * @flags: command options
374 * @read_write: read from or write to device
375 * @command: the i2c/SMBus command to issue
376 * @size: SMBus transaction type
377 * @data: read/write data buffer
378 */
379 static int ismt_access(struct i2c_adapter *adap, u16 addr,
380 unsigned short flags, char read_write, u8 command,
381 int size, union i2c_smbus_data *data)
382 {
383 int ret;
384 unsigned long time_left;
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 DMA buffer */
395 memset(priv->dma_buffer, 0, sizeof(priv->dma_buffer));
396
397 /* Initialize the descriptor */
398 memset(desc, 0, sizeof(struct ismt_desc));
399 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
400
401 /* Initialize common control bits */
402 if (likely(pci_dev_msi_enabled(priv->pci_dev)))
403 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
404 else
405 desc->control = ISMT_DESC_FAIR;
406
407 if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
408 && (size != I2C_SMBUS_I2C_BLOCK_DATA))
409 desc->control |= ISMT_DESC_PEC;
410
411 switch (size) {
412 case I2C_SMBUS_QUICK:
413 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
414 break;
415
416 case I2C_SMBUS_BYTE:
417 if (read_write == I2C_SMBUS_WRITE) {
418 /*
419 * Send Byte
420 * The command field contains the write data
421 */
422 dev_dbg(dev, "I2C_SMBUS_BYTE: WRITE\n");
423 desc->control |= ISMT_DESC_CWRL;
424 desc->wr_len_cmd = command;
425 } else {
426 /* Receive Byte */
427 dev_dbg(dev, "I2C_SMBUS_BYTE: READ\n");
428 dma_size = 1;
429 dma_direction = DMA_FROM_DEVICE;
430 desc->rd_len = 1;
431 }
432 break;
433
434 case I2C_SMBUS_BYTE_DATA:
435 if (read_write == I2C_SMBUS_WRITE) {
436 /*
437 * Write Byte
438 * Command plus 1 data byte
439 */
440 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
441 desc->wr_len_cmd = 2;
442 dma_size = 2;
443 dma_direction = DMA_TO_DEVICE;
444 priv->dma_buffer[0] = command;
445 priv->dma_buffer[1] = data->byte;
446 } else {
447 /* Read Byte */
448 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: READ\n");
449 desc->control |= ISMT_DESC_CWRL;
450 desc->wr_len_cmd = command;
451 desc->rd_len = 1;
452 dma_size = 1;
453 dma_direction = DMA_FROM_DEVICE;
454 }
455 break;
456
457 case I2C_SMBUS_WORD_DATA:
458 if (read_write == I2C_SMBUS_WRITE) {
459 /* Write Word */
460 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
461 desc->wr_len_cmd = 3;
462 dma_size = 3;
463 dma_direction = DMA_TO_DEVICE;
464 priv->dma_buffer[0] = command;
465 priv->dma_buffer[1] = data->word & 0xff;
466 priv->dma_buffer[2] = data->word >> 8;
467 } else {
468 /* Read Word */
469 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: READ\n");
470 desc->wr_len_cmd = command;
471 desc->control |= ISMT_DESC_CWRL;
472 desc->rd_len = 2;
473 dma_size = 2;
474 dma_direction = DMA_FROM_DEVICE;
475 }
476 break;
477
478 case I2C_SMBUS_PROC_CALL:
479 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
480 desc->wr_len_cmd = 3;
481 desc->rd_len = 2;
482 dma_size = 3;
483 dma_direction = DMA_BIDIRECTIONAL;
484 priv->dma_buffer[0] = command;
485 priv->dma_buffer[1] = data->word & 0xff;
486 priv->dma_buffer[2] = data->word >> 8;
487 break;
488
489 case I2C_SMBUS_BLOCK_DATA:
490 if (read_write == I2C_SMBUS_WRITE) {
491 /* Block Write */
492 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n");
493 dma_size = data->block[0] + 1;
494 dma_direction = DMA_TO_DEVICE;
495 desc->wr_len_cmd = dma_size;
496 desc->control |= ISMT_DESC_BLK;
497 priv->dma_buffer[0] = command;
498 memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
499 } else {
500 /* Block Read */
501 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
502 dma_size = I2C_SMBUS_BLOCK_MAX;
503 dma_direction = DMA_FROM_DEVICE;
504 desc->rd_len = dma_size;
505 desc->wr_len_cmd = command;
506 desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
507 }
508 break;
509
510 case I2C_SMBUS_I2C_BLOCK_DATA:
511 /* Make sure the length is valid */
512 if (data->block[0] < 1)
513 data->block[0] = 1;
514
515 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
516 data->block[0] = I2C_SMBUS_BLOCK_MAX;
517
518 if (read_write == I2C_SMBUS_WRITE) {
519 /* i2c Block Write */
520 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: WRITE\n");
521 dma_size = data->block[0] + 1;
522 dma_direction = DMA_TO_DEVICE;
523 desc->wr_len_cmd = dma_size;
524 desc->control |= ISMT_DESC_I2C;
525 priv->dma_buffer[0] = command;
526 memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
527 } else {
528 /* i2c Block Read */
529 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: READ\n");
530 dma_size = data->block[0];
531 dma_direction = DMA_FROM_DEVICE;
532 desc->rd_len = dma_size;
533 desc->wr_len_cmd = command;
534 desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
535 /*
536 * Per the "Table 15-15. I2C Commands",
537 * in the External Design Specification (EDS),
538 * (Document Number: 508084, Revision: 2.0),
539 * the _rw bit must be 0
540 */
541 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
542 }
543 break;
544
545 default:
546 dev_err(dev, "Unsupported transaction %d\n",
547 size);
548 return -EOPNOTSUPP;
549 }
550
551 /* map the data buffer */
552 if (dma_size != 0) {
553 dev_dbg(dev, " dev=%p\n", dev);
554 dev_dbg(dev, " data=%p\n", data);
555 dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
556 dev_dbg(dev, " dma_size=%d\n", dma_size);
557 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
558
559 dma_addr = dma_map_single(dev,
560 priv->dma_buffer,
561 dma_size,
562 dma_direction);
563
564 if (dma_mapping_error(dev, dma_addr)) {
565 dev_err(dev, "Error in mapping dma buffer %p\n",
566 priv->dma_buffer);
567 return -EIO;
568 }
569
570 dev_dbg(dev, " dma_addr = 0x%016llX\n",
571 (unsigned long long)dma_addr);
572
573 desc->dptr_low = lower_32_bits(dma_addr);
574 desc->dptr_high = upper_32_bits(dma_addr);
575 }
576
577 reinit_completion(&priv->cmp);
578
579 /* Add the descriptor */
580 ismt_submit_desc(priv);
581
582 /* Now we wait for interrupt completion, 1s */
583 time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
584
585 /* unmap the data buffer */
586 if (dma_size != 0)
587 dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
588
589 if (unlikely(!time_left)) {
590 dev_err(dev, "completion wait timed out\n");
591 ret = -ETIMEDOUT;
592 goto out;
593 }
594
595 /* do any post processing of the descriptor here */
596 ret = ismt_process_desc(desc, data, priv, size, read_write);
597
598 out:
599 /* Update the ring pointer */
600 priv->head++;
601 priv->head %= ISMT_DESC_ENTRIES;
602
603 return ret;
604 }
605
606 /**
607 * ismt_func() - report which i2c commands are supported by this adapter
608 * @adap: the i2c host adapter
609 */
610 static u32 ismt_func(struct i2c_adapter *adap)
611 {
612 return I2C_FUNC_SMBUS_QUICK |
613 I2C_FUNC_SMBUS_BYTE |
614 I2C_FUNC_SMBUS_BYTE_DATA |
615 I2C_FUNC_SMBUS_WORD_DATA |
616 I2C_FUNC_SMBUS_PROC_CALL |
617 I2C_FUNC_SMBUS_BLOCK_DATA |
618 I2C_FUNC_SMBUS_I2C_BLOCK |
619 I2C_FUNC_SMBUS_PEC;
620 }
621
622 /**
623 * smbus_algorithm - the adapter algorithm and supported functionality
624 * @smbus_xfer: the adapter algorithm
625 * @functionality: functionality supported by the adapter
626 */
627 static const struct i2c_algorithm smbus_algorithm = {
628 .smbus_xfer = ismt_access,
629 .functionality = ismt_func,
630 };
631
632 /**
633 * ismt_handle_isr() - interrupt handler bottom half
634 * @priv: iSMT private data
635 */
636 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
637 {
638 complete(&priv->cmp);
639
640 return IRQ_HANDLED;
641 }
642
643
644 /**
645 * ismt_do_interrupt() - IRQ interrupt handler
646 * @vec: interrupt vector
647 * @data: iSMT private data
648 */
649 static irqreturn_t ismt_do_interrupt(int vec, void *data)
650 {
651 u32 val;
652 struct ismt_priv *priv = data;
653
654 /*
655 * check to see it's our interrupt, return IRQ_NONE if not ours
656 * since we are sharing interrupt
657 */
658 val = readl(priv->smba + ISMT_MSTR_MSTS);
659
660 if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
661 return IRQ_NONE;
662 else
663 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
664 priv->smba + ISMT_MSTR_MSTS);
665
666 return ismt_handle_isr(priv);
667 }
668
669 /**
670 * ismt_do_msi_interrupt() - MSI interrupt handler
671 * @vec: interrupt vector
672 * @data: iSMT private data
673 */
674 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
675 {
676 return ismt_handle_isr(data);
677 }
678
679 /**
680 * ismt_hw_init() - initialize the iSMT hardware
681 * @priv: iSMT private data
682 */
683 static void ismt_hw_init(struct ismt_priv *priv)
684 {
685 u32 val;
686 struct device *dev = &priv->pci_dev->dev;
687
688 /* initialize the Master Descriptor Base Address (MDBA) */
689 writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
690
691 /* initialize the Master Control Register (MCTRL) */
692 writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
693
694 /* initialize the Master Status Register (MSTS) */
695 writel(0, priv->smba + ISMT_MSTR_MSTS);
696
697 /* initialize the Master Descriptor Size (MDS) */
698 val = readl(priv->smba + ISMT_MSTR_MDS);
699 writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
700 priv->smba + ISMT_MSTR_MDS);
701
702 /*
703 * Set the SMBus speed (could use this for slow HW debuggers)
704 */
705
706 val = readl(priv->smba + ISMT_SPGT);
707
708 switch (bus_speed) {
709 case 0:
710 break;
711
712 case 80:
713 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
714 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
715 priv->smba + ISMT_SPGT);
716 break;
717
718 case 100:
719 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
720 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
721 priv->smba + ISMT_SPGT);
722 break;
723
724 case 400:
725 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
726 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
727 priv->smba + ISMT_SPGT);
728 break;
729
730 case 1000:
731 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
732 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
733 priv->smba + ISMT_SPGT);
734 break;
735
736 default:
737 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
738 break;
739 }
740
741 val = readl(priv->smba + ISMT_SPGT);
742
743 switch (val & ISMT_SPGT_SPD_MASK) {
744 case ISMT_SPGT_SPD_80K:
745 bus_speed = 80;
746 break;
747 case ISMT_SPGT_SPD_100K:
748 bus_speed = 100;
749 break;
750 case ISMT_SPGT_SPD_400K:
751 bus_speed = 400;
752 break;
753 case ISMT_SPGT_SPD_1M:
754 bus_speed = 1000;
755 break;
756 }
757 dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
758 }
759
760 /**
761 * ismt_dev_init() - initialize the iSMT data structures
762 * @priv: iSMT private data
763 */
764 static int ismt_dev_init(struct ismt_priv *priv)
765 {
766 /* allocate memory for the descriptor */
767 priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
768 (ISMT_DESC_ENTRIES
769 * sizeof(struct ismt_desc)),
770 &priv->io_rng_dma,
771 GFP_KERNEL);
772 if (!priv->hw)
773 return -ENOMEM;
774
775 memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
776
777 priv->head = 0;
778 init_completion(&priv->cmp);
779
780 return 0;
781 }
782
783 /**
784 * ismt_int_init() - initialize interrupts
785 * @priv: iSMT private data
786 */
787 static int ismt_int_init(struct ismt_priv *priv)
788 {
789 int err;
790
791 /* Try using MSI interrupts */
792 err = pci_enable_msi(priv->pci_dev);
793 if (err)
794 goto intx;
795
796 err = devm_request_irq(&priv->pci_dev->dev,
797 priv->pci_dev->irq,
798 ismt_do_msi_interrupt,
799 0,
800 "ismt-msi",
801 priv);
802 if (err) {
803 pci_disable_msi(priv->pci_dev);
804 goto intx;
805 }
806
807 return 0;
808
809 /* Try using legacy interrupts */
810 intx:
811 dev_warn(&priv->pci_dev->dev,
812 "Unable to use MSI interrupts, falling back to legacy\n");
813
814 err = devm_request_irq(&priv->pci_dev->dev,
815 priv->pci_dev->irq,
816 ismt_do_interrupt,
817 IRQF_SHARED,
818 "ismt-intx",
819 priv);
820 if (err) {
821 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
822 return err;
823 }
824
825 return 0;
826 }
827
828 static struct pci_driver ismt_driver;
829
830 /**
831 * ismt_probe() - probe for iSMT devices
832 * @pdev: PCI-Express device
833 * @id: PCI-Express device ID
834 */
835 static int
836 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
837 {
838 int err;
839 struct ismt_priv *priv;
840 unsigned long start, len;
841
842 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
843 if (!priv)
844 return -ENOMEM;
845
846 pci_set_drvdata(pdev, priv);
847
848 i2c_set_adapdata(&priv->adapter, priv);
849 priv->adapter.owner = THIS_MODULE;
850 priv->adapter.class = I2C_CLASS_HWMON;
851 priv->adapter.algo = &smbus_algorithm;
852 priv->adapter.dev.parent = &pdev->dev;
853 ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
854 priv->adapter.retries = ISMT_MAX_RETRIES;
855
856 priv->pci_dev = pdev;
857
858 err = pcim_enable_device(pdev);
859 if (err) {
860 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
861 err);
862 return err;
863 }
864
865 /* enable bus mastering */
866 pci_set_master(pdev);
867
868 /* Determine the address of the SMBus area */
869 start = pci_resource_start(pdev, SMBBAR);
870 len = pci_resource_len(pdev, SMBBAR);
871 if (!start || !len) {
872 dev_err(&pdev->dev,
873 "SMBus base address uninitialized, upgrade BIOS\n");
874 return -ENODEV;
875 }
876
877 snprintf(priv->adapter.name, sizeof(priv->adapter.name),
878 "SMBus iSMT adapter at %lx", start);
879
880 dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
881 dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
882
883 err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
884 if (err) {
885 dev_err(&pdev->dev, "ACPI resource conflict!\n");
886 return err;
887 }
888
889 err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
890 if (err) {
891 dev_err(&pdev->dev,
892 "Failed to request SMBus region 0x%lx-0x%lx\n",
893 start, start + len);
894 return err;
895 }
896
897 priv->smba = pcim_iomap(pdev, SMBBAR, len);
898 if (!priv->smba) {
899 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
900 return -ENODEV;
901 }
902
903 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
904 (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
905 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
906 (pci_set_consistent_dma_mask(pdev,
907 DMA_BIT_MASK(32)) != 0)) {
908 dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
909 pdev);
910 return -ENODEV;
911 }
912 }
913
914 err = ismt_dev_init(priv);
915 if (err)
916 return err;
917
918 ismt_hw_init(priv);
919
920 err = ismt_int_init(priv);
921 if (err)
922 return err;
923
924 err = i2c_add_adapter(&priv->adapter);
925 if (err)
926 return -ENODEV;
927 return 0;
928 }
929
930 /**
931 * ismt_remove() - release driver resources
932 * @pdev: PCI-Express device
933 */
934 static void ismt_remove(struct pci_dev *pdev)
935 {
936 struct ismt_priv *priv = pci_get_drvdata(pdev);
937
938 i2c_del_adapter(&priv->adapter);
939 }
940
941 static struct pci_driver ismt_driver = {
942 .name = "ismt_smbus",
943 .id_table = ismt_ids,
944 .probe = ismt_probe,
945 .remove = ismt_remove,
946 };
947
948 module_pci_driver(ismt_driver);
949
950 MODULE_LICENSE("Dual BSD/GPL");
951 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
952 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");
Linux with added FPC-III support