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50 * Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
51 * S12xx Product Family.
53 * Features supported by this driver:
56 * Block process call transaction 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 */
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
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 */
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 */
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 */
106 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
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 */
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 */
123 /* iSMT Miscellaneous Registers */
124 #define ISMT_SPGT 0x300 /* SMBus PHY Global Timing */
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 */
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) */
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 */
142 /* Master Descriptor Size (MDS) bit definitions */
143 #define ISMT_MDS_MASK 0xff /* Master Descriptor Size mask (MDS) */
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 */
153 /* MSI Control Register (MSICTL) bit definitions */
154 #define ISMT_MSICTL_MSIE 0x01 /* MSI Enable */
156 /* iSMT Hardware Descriptor */
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 */
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 */
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) },
193 MODULE_DEVICE_TABLE(pci, ismt_ids);
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)");
201 * __ismt_desc_dump() - dump the contents of a specific descriptor
202 * @dev: the iSMT device
203 * @desc: the iSMT hardware descriptor
205 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
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);
221 * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
222 * @priv: iSMT private data
224 static void ismt_desc_dump(struct ismt_priv *priv)
226 struct device *dev = &priv->pci_dev->dev;
227 struct ismt_desc *desc = &priv->hw[priv->head];
229 dev_dbg(dev, "Dump of the descriptor struct: 0x%X\n", priv->head);
230 __ismt_desc_dump(dev, desc);
234 * ismt_gen_reg_dump() - dump the iSMT General Registers
235 * @priv: iSMT private data
237 static void ismt_gen_reg_dump(struct ismt_priv *priv)
239 struct device *dev = &priv->pci_dev->dev;
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));
263 * ismt_mstr_reg_dump() - dump the iSMT Master Registers
264 * @priv: iSMT private data
266 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
268 struct device *dev = &priv->pci_dev->dev;
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));
292 * ismt_submit_desc() - add a descriptor to the ring
293 * @priv: iSMT private data
295 static void ismt_submit_desc(struct ismt_priv *priv)
300 ismt_desc_dump(priv);
301 ismt_gen_reg_dump(priv);
302 ismt_mstr_reg_dump(priv);
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);
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);
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
324 static int ismt_process_desc(const struct ismt_desc *desc,
325 union i2c_smbus_data *data,
326 struct ismt_priv *priv, int size,
329 u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
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);
336 if (desc->status & ISMT_DESC_SCS) {
337 if (read_write == I2C_SMBUS_WRITE &&
338 size != I2C_SMBUS_PROC_CALL)
343 case I2C_SMBUS_BYTE_DATA:
344 data->byte = dma_buffer[0];
346 case I2C_SMBUS_WORD_DATA:
347 case I2C_SMBUS_PROC_CALL:
348 data->word = dma_buffer[0] | (dma_buffer[1] << 8);
350 case I2C_SMBUS_BLOCK_DATA:
351 if (desc->rxbytes != dma_buffer[0] + 1)
354 memcpy(data->block, dma_buffer, desc->rxbytes);
356 case I2C_SMBUS_I2C_BLOCK_DATA:
357 memcpy(&data->block[1], dma_buffer, desc->rxbytes);
358 data->block[0] = desc->rxbytes;
364 if (likely(desc->status & ISMT_DESC_NAK))
367 if (desc->status & ISMT_DESC_CRC)
370 if (desc->status & ISMT_DESC_COL)
373 if (desc->status & ISMT_DESC_LPR)
376 if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
383 * ismt_access() - process an SMBus command
384 * @adap: the i2c host adapter
385 * @addr: address of the i2c/SMBus target
386 * @flags: command options
387 * @read_write: read from or write to device
388 * @command: the i2c/SMBus command to issue
389 * @size: SMBus transaction type
390 * @data: read/write data buffer
392 static int ismt_access(struct i2c_adapter *adap, u16 addr,
393 unsigned short flags, char read_write, u8 command,
394 int size, union i2c_smbus_data *data)
397 unsigned long time_left;
398 dma_addr_t dma_addr = 0; /* address of the data buffer */
400 enum dma_data_direction dma_direction = 0;
401 struct ismt_desc *desc;
402 struct ismt_priv *priv = i2c_get_adapdata(adap);
403 struct device *dev = &priv->pci_dev->dev;
404 u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
406 desc = &priv->hw[priv->head];
408 /* Initialize the DMA buffer */
409 memset(priv->buffer, 0, sizeof(priv->buffer));
411 /* Initialize the descriptor */
412 memset(desc, 0, sizeof(struct ismt_desc));
413 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
415 /* Always clear the log entries */
416 memset(priv->log, 0, ISMT_LOG_ENTRIES * sizeof(u32));
418 /* Initialize common control bits */
419 if (likely(pci_dev_msi_enabled(priv->pci_dev)))
420 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
422 desc->control = ISMT_DESC_FAIR;
424 if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
425 && (size != I2C_SMBUS_I2C_BLOCK_DATA))
426 desc->control |= ISMT_DESC_PEC;
429 case I2C_SMBUS_QUICK:
430 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
434 if (read_write == I2C_SMBUS_WRITE) {
437 * The command field contains the write data
439 dev_dbg(dev, "I2C_SMBUS_BYTE: WRITE\n");
440 desc->control |= ISMT_DESC_CWRL;
441 desc->wr_len_cmd = command;
444 dev_dbg(dev, "I2C_SMBUS_BYTE: READ\n");
446 dma_direction = DMA_FROM_DEVICE;
451 case I2C_SMBUS_BYTE_DATA:
452 if (read_write == I2C_SMBUS_WRITE) {
455 * Command plus 1 data byte
457 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
458 desc->wr_len_cmd = 2;
460 dma_direction = DMA_TO_DEVICE;
461 dma_buffer[0] = command;
462 dma_buffer[1] = data->byte;
465 dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: READ\n");
466 desc->control |= ISMT_DESC_CWRL;
467 desc->wr_len_cmd = command;
470 dma_direction = DMA_FROM_DEVICE;
474 case I2C_SMBUS_WORD_DATA:
475 if (read_write == I2C_SMBUS_WRITE) {
477 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
478 desc->wr_len_cmd = 3;
480 dma_direction = DMA_TO_DEVICE;
481 dma_buffer[0] = command;
482 dma_buffer[1] = data->word & 0xff;
483 dma_buffer[2] = data->word >> 8;
486 dev_dbg(dev, "I2C_SMBUS_WORD_DATA: READ\n");
487 desc->wr_len_cmd = command;
488 desc->control |= ISMT_DESC_CWRL;
491 dma_direction = DMA_FROM_DEVICE;
495 case I2C_SMBUS_PROC_CALL:
496 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
497 desc->wr_len_cmd = 3;
500 dma_direction = DMA_BIDIRECTIONAL;
501 dma_buffer[0] = command;
502 dma_buffer[1] = data->word & 0xff;
503 dma_buffer[2] = data->word >> 8;
506 case I2C_SMBUS_BLOCK_DATA:
507 if (read_write == I2C_SMBUS_WRITE) {
509 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n");
510 if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
513 dma_size = data->block[0] + 1;
514 dma_direction = DMA_TO_DEVICE;
515 desc->wr_len_cmd = dma_size;
516 desc->control |= ISMT_DESC_BLK;
517 dma_buffer[0] = command;
518 memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
521 dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
522 dma_size = I2C_SMBUS_BLOCK_MAX;
523 dma_direction = DMA_FROM_DEVICE;
524 desc->rd_len = dma_size;
525 desc->wr_len_cmd = command;
526 desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
530 case I2C_SMBUS_I2C_BLOCK_DATA:
531 /* Make sure the length is valid */
532 if (data->block[0] < 1)
535 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
536 data->block[0] = I2C_SMBUS_BLOCK_MAX;
538 if (read_write == I2C_SMBUS_WRITE) {
539 /* i2c Block Write */
540 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: WRITE\n");
541 dma_size = data->block[0] + 1;
542 dma_direction = DMA_TO_DEVICE;
543 desc->wr_len_cmd = dma_size;
544 desc->control |= ISMT_DESC_I2C;
545 dma_buffer[0] = command;
546 memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
549 dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: READ\n");
550 dma_size = data->block[0];
551 dma_direction = DMA_FROM_DEVICE;
552 desc->rd_len = dma_size;
553 desc->wr_len_cmd = command;
554 desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
556 * Per the "Table 15-15. I2C Commands",
557 * in the External Design Specification (EDS),
558 * (Document Number: 508084, Revision: 2.0),
559 * the _rw bit must be 0
561 desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
566 dev_err(dev, "Unsupported transaction %d\n",
571 /* map the data buffer */
573 dev_dbg(dev, " dev=%p\n", dev);
574 dev_dbg(dev, " data=%p\n", data);
575 dev_dbg(dev, " dma_buffer=%p\n", dma_buffer);
576 dev_dbg(dev, " dma_size=%d\n", dma_size);
577 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
579 dma_addr = dma_map_single(dev,
584 if (dma_mapping_error(dev, dma_addr)) {
585 dev_err(dev, "Error in mapping dma buffer %p\n",
590 dev_dbg(dev, " dma_addr = %pad\n", &dma_addr);
592 desc->dptr_low = lower_32_bits(dma_addr);
593 desc->dptr_high = upper_32_bits(dma_addr);
596 reinit_completion(&priv->cmp);
598 /* Add the descriptor */
599 ismt_submit_desc(priv);
601 /* Now we wait for interrupt completion, 1s */
602 time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
604 /* unmap the data buffer */
606 dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
608 if (unlikely(!time_left)) {
609 dev_err(dev, "completion wait timed out\n");
614 /* do any post processing of the descriptor here */
615 ret = ismt_process_desc(desc, data, priv, size, read_write);
618 /* Update the ring pointer */
620 priv->head %= ISMT_DESC_ENTRIES;
626 * ismt_func() - report which i2c commands are supported by this adapter
627 * @adap: the i2c host adapter
629 static u32 ismt_func(struct i2c_adapter *adap)
631 return I2C_FUNC_SMBUS_QUICK |
632 I2C_FUNC_SMBUS_BYTE |
633 I2C_FUNC_SMBUS_BYTE_DATA |
634 I2C_FUNC_SMBUS_WORD_DATA |
635 I2C_FUNC_SMBUS_PROC_CALL |
636 I2C_FUNC_SMBUS_BLOCK_DATA |
637 I2C_FUNC_SMBUS_I2C_BLOCK |
641 static const struct i2c_algorithm smbus_algorithm = {
642 .smbus_xfer = ismt_access,
643 .functionality = ismt_func,
647 * ismt_handle_isr() - interrupt handler bottom half
648 * @priv: iSMT private data
650 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
652 complete(&priv->cmp);
659 * ismt_do_interrupt() - IRQ interrupt handler
660 * @vec: interrupt vector
661 * @data: iSMT private data
663 static irqreturn_t ismt_do_interrupt(int vec, void *data)
666 struct ismt_priv *priv = data;
669 * check to see it's our interrupt, return IRQ_NONE if not ours
670 * since we are sharing interrupt
672 val = readl(priv->smba + ISMT_MSTR_MSTS);
674 if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
677 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
678 priv->smba + ISMT_MSTR_MSTS);
680 return ismt_handle_isr(priv);
684 * ismt_do_msi_interrupt() - MSI interrupt handler
685 * @vec: interrupt vector
686 * @data: iSMT private data
688 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
690 return ismt_handle_isr(data);
694 * ismt_hw_init() - initialize the iSMT hardware
695 * @priv: iSMT private data
697 static void ismt_hw_init(struct ismt_priv *priv)
700 struct device *dev = &priv->pci_dev->dev;
702 /* initialize the Master Descriptor Base Address (MDBA) */
703 writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
705 writeq(priv->log_dma, priv->smba + ISMT_GR_SMTICL);
707 /* initialize the Master Control Register (MCTRL) */
708 writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
710 /* initialize the Master Status Register (MSTS) */
711 writel(0, priv->smba + ISMT_MSTR_MSTS);
713 /* initialize the Master Descriptor Size (MDS) */
714 val = readl(priv->smba + ISMT_MSTR_MDS);
715 writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
716 priv->smba + ISMT_MSTR_MDS);
719 * Set the SMBus speed (could use this for slow HW debuggers)
722 val = readl(priv->smba + ISMT_SPGT);
729 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
730 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
731 priv->smba + ISMT_SPGT);
735 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
736 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
737 priv->smba + ISMT_SPGT);
741 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
742 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
743 priv->smba + ISMT_SPGT);
747 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
748 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
749 priv->smba + ISMT_SPGT);
753 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
757 val = readl(priv->smba + ISMT_SPGT);
759 switch (val & ISMT_SPGT_SPD_MASK) {
760 case ISMT_SPGT_SPD_80K:
763 case ISMT_SPGT_SPD_100K:
766 case ISMT_SPGT_SPD_400K:
769 case ISMT_SPGT_SPD_1M:
773 dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
777 * ismt_dev_init() - initialize the iSMT data structures
778 * @priv: iSMT private data
780 static int ismt_dev_init(struct ismt_priv *priv)
782 /* allocate memory for the descriptor */
783 priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
785 * sizeof(struct ismt_desc)),
792 init_completion(&priv->cmp);
794 priv->log = dmam_alloc_coherent(&priv->pci_dev->dev,
795 ISMT_LOG_ENTRIES * sizeof(u32),
796 &priv->log_dma, GFP_KERNEL);
804 * ismt_int_init() - initialize interrupts
805 * @priv: iSMT private data
807 static int ismt_int_init(struct ismt_priv *priv)
811 /* Try using MSI interrupts */
812 err = pci_enable_msi(priv->pci_dev);
816 err = devm_request_irq(&priv->pci_dev->dev,
818 ismt_do_msi_interrupt,
823 pci_disable_msi(priv->pci_dev);
829 /* Try using legacy interrupts */
831 dev_warn(&priv->pci_dev->dev,
832 "Unable to use MSI interrupts, falling back to legacy\n");
834 err = devm_request_irq(&priv->pci_dev->dev,
841 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
848 static struct pci_driver ismt_driver;
851 * ismt_probe() - probe for iSMT devices
852 * @pdev: PCI-Express device
853 * @id: PCI-Express device ID
856 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
859 struct ismt_priv *priv;
860 unsigned long start, len;
862 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
866 pci_set_drvdata(pdev, priv);
868 i2c_set_adapdata(&priv->adapter, priv);
869 priv->adapter.owner = THIS_MODULE;
870 priv->adapter.class = I2C_CLASS_HWMON;
871 priv->adapter.algo = &smbus_algorithm;
872 priv->adapter.dev.parent = &pdev->dev;
873 ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
874 priv->adapter.retries = ISMT_MAX_RETRIES;
876 priv->pci_dev = pdev;
878 err = pcim_enable_device(pdev);
880 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
885 /* enable bus mastering */
886 pci_set_master(pdev);
888 /* Determine the address of the SMBus area */
889 start = pci_resource_start(pdev, SMBBAR);
890 len = pci_resource_len(pdev, SMBBAR);
891 if (!start || !len) {
893 "SMBus base address uninitialized, upgrade BIOS\n");
897 snprintf(priv->adapter.name, sizeof(priv->adapter.name),
898 "SMBus iSMT adapter at %lx", start);
900 dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
901 dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
903 err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
905 dev_err(&pdev->dev, "ACPI resource conflict!\n");
909 err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
912 "Failed to request SMBus region 0x%lx-0x%lx\n",
917 priv->smba = pcim_iomap(pdev, SMBBAR, len);
919 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
923 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
924 (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
925 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
926 (pci_set_consistent_dma_mask(pdev,
927 DMA_BIT_MASK(32)) != 0)) {
928 dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
934 err = ismt_dev_init(priv);
940 err = ismt_int_init(priv);
944 err = i2c_add_adapter(&priv->adapter);
951 * ismt_remove() - release driver resources
952 * @pdev: PCI-Express device
954 static void ismt_remove(struct pci_dev *pdev)
956 struct ismt_priv *priv = pci_get_drvdata(pdev);
958 i2c_del_adapter(&priv->adapter);
961 static struct pci_driver ismt_driver = {
962 .name = "ismt_smbus",
963 .id_table = ismt_ids,
965 .remove = ismt_remove,
968 module_pci_driver(ismt_driver);
970 MODULE_LICENSE("Dual BSD/GPL");
971 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
972 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");