xref: /linux/drivers/spi/spi-topcliff-pch.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /*
2  * SPI bus driver for the Topcliff PCH used by Intel SoCs
3  *
4  * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
18  */
19 
20 #include <linux/delay.h>
21 #include <linux/pci.h>
22 #include <linux/wait.h>
23 #include <linux/spi/spi.h>
24 #include <linux/interrupt.h>
25 #include <linux/sched.h>
26 #include <linux/spi/spidev.h>
27 #include <linux/module.h>
28 #include <linux/device.h>
29 #include <linux/platform_device.h>
30 
31 #include <linux/dmaengine.h>
32 #include <linux/pch_dma.h>
33 
34 /* Register offsets */
35 #define PCH_SPCR		0x00	/* SPI control register */
36 #define PCH_SPBRR		0x04	/* SPI baud rate register */
37 #define PCH_SPSR		0x08	/* SPI status register */
38 #define PCH_SPDWR		0x0C	/* SPI write data register */
39 #define PCH_SPDRR		0x10	/* SPI read data register */
40 #define PCH_SSNXCR		0x18	/* SSN Expand Control Register */
41 #define PCH_SRST		0x1C	/* SPI reset register */
42 #define PCH_ADDRESS_SIZE	0x20
43 
44 #define PCH_SPSR_TFD		0x000007C0
45 #define PCH_SPSR_RFD		0x0000F800
46 
47 #define PCH_READABLE(x)		(((x) & PCH_SPSR_RFD)>>11)
48 #define PCH_WRITABLE(x)		(((x) & PCH_SPSR_TFD)>>6)
49 
50 #define PCH_RX_THOLD		7
51 #define PCH_RX_THOLD_MAX	15
52 
53 #define PCH_TX_THOLD		2
54 
55 #define PCH_MAX_BAUDRATE	5000000
56 #define PCH_MAX_FIFO_DEPTH	16
57 
58 #define STATUS_RUNNING		1
59 #define STATUS_EXITING		2
60 #define PCH_SLEEP_TIME		10
61 
62 #define SSN_LOW			0x02U
63 #define SSN_HIGH		0x03U
64 #define SSN_NO_CONTROL		0x00U
65 #define PCH_MAX_CS		0xFF
66 #define PCI_DEVICE_ID_GE_SPI	0x8816
67 
68 #define SPCR_SPE_BIT		(1 << 0)
69 #define SPCR_MSTR_BIT		(1 << 1)
70 #define SPCR_LSBF_BIT		(1 << 4)
71 #define SPCR_CPHA_BIT		(1 << 5)
72 #define SPCR_CPOL_BIT		(1 << 6)
73 #define SPCR_TFIE_BIT		(1 << 8)
74 #define SPCR_RFIE_BIT		(1 << 9)
75 #define SPCR_FIE_BIT		(1 << 10)
76 #define SPCR_ORIE_BIT		(1 << 11)
77 #define SPCR_MDFIE_BIT		(1 << 12)
78 #define SPCR_FICLR_BIT		(1 << 24)
79 #define SPSR_TFI_BIT		(1 << 0)
80 #define SPSR_RFI_BIT		(1 << 1)
81 #define SPSR_FI_BIT		(1 << 2)
82 #define SPSR_ORF_BIT		(1 << 3)
83 #define SPBRR_SIZE_BIT		(1 << 10)
84 
85 #define PCH_ALL			(SPCR_TFIE_BIT|SPCR_RFIE_BIT|SPCR_FIE_BIT|\
86 				SPCR_ORIE_BIT|SPCR_MDFIE_BIT)
87 
88 #define SPCR_RFIC_FIELD		20
89 #define SPCR_TFIC_FIELD		16
90 
91 #define MASK_SPBRR_SPBR_BITS	((1 << 10) - 1)
92 #define MASK_RFIC_SPCR_BITS	(0xf << SPCR_RFIC_FIELD)
93 #define MASK_TFIC_SPCR_BITS	(0xf << SPCR_TFIC_FIELD)
94 
95 #define PCH_CLOCK_HZ		50000000
96 #define PCH_MAX_SPBR		1023
97 
98 /* Definition for ML7213/ML7223/ML7831 by LAPIS Semiconductor */
99 #define PCI_VENDOR_ID_ROHM		0x10DB
100 #define PCI_DEVICE_ID_ML7213_SPI	0x802c
101 #define PCI_DEVICE_ID_ML7223_SPI	0x800F
102 #define PCI_DEVICE_ID_ML7831_SPI	0x8816
103 
104 /*
105  * Set the number of SPI instance max
106  * Intel EG20T PCH :		1ch
107  * LAPIS Semiconductor ML7213 IOH :	2ch
108  * LAPIS Semiconductor ML7223 IOH :	1ch
109  * LAPIS Semiconductor ML7831 IOH :	1ch
110 */
111 #define PCH_SPI_MAX_DEV			2
112 
113 #define PCH_BUF_SIZE		4096
114 #define PCH_DMA_TRANS_SIZE	12
115 
116 static int use_dma = 1;
117 
118 struct pch_spi_dma_ctrl {
119 	struct dma_async_tx_descriptor	*desc_tx;
120 	struct dma_async_tx_descriptor	*desc_rx;
121 	struct pch_dma_slave		param_tx;
122 	struct pch_dma_slave		param_rx;
123 	struct dma_chan		*chan_tx;
124 	struct dma_chan		*chan_rx;
125 	struct scatterlist		*sg_tx_p;
126 	struct scatterlist		*sg_rx_p;
127 	struct scatterlist		sg_tx;
128 	struct scatterlist		sg_rx;
129 	int				nent;
130 	void				*tx_buf_virt;
131 	void				*rx_buf_virt;
132 	dma_addr_t			tx_buf_dma;
133 	dma_addr_t			rx_buf_dma;
134 };
135 /**
136  * struct pch_spi_data - Holds the SPI channel specific details
137  * @io_remap_addr:		The remapped PCI base address
138  * @master:			Pointer to the SPI master structure
139  * @work:			Reference to work queue handler
140  * @wk:				Workqueue for carrying out execution of the
141  *				requests
142  * @wait:			Wait queue for waking up upon receiving an
143  *				interrupt.
144  * @transfer_complete:		Status of SPI Transfer
145  * @bcurrent_msg_processing:	Status flag for message processing
146  * @lock:			Lock for protecting this structure
147  * @queue:			SPI Message queue
148  * @status:			Status of the SPI driver
149  * @bpw_len:			Length of data to be transferred in bits per
150  *				word
151  * @transfer_active:		Flag showing active transfer
152  * @tx_index:			Transmit data count; for bookkeeping during
153  *				transfer
154  * @rx_index:			Receive data count; for bookkeeping during
155  *				transfer
156  * @tx_buff:			Buffer for data to be transmitted
157  * @rx_index:			Buffer for Received data
158  * @n_curnt_chip:		The chip number that this SPI driver currently
159  *				operates on
160  * @current_chip:		Reference to the current chip that this SPI
161  *				driver currently operates on
162  * @current_msg:		The current message that this SPI driver is
163  *				handling
164  * @cur_trans:			The current transfer that this SPI driver is
165  *				handling
166  * @board_dat:			Reference to the SPI device data structure
167  * @plat_dev:			platform_device structure
168  * @ch:				SPI channel number
169  * @irq_reg_sts:		Status of IRQ registration
170  */
171 struct pch_spi_data {
172 	void __iomem *io_remap_addr;
173 	unsigned long io_base_addr;
174 	struct spi_master *master;
175 	struct work_struct work;
176 	struct workqueue_struct *wk;
177 	wait_queue_head_t wait;
178 	u8 transfer_complete;
179 	u8 bcurrent_msg_processing;
180 	spinlock_t lock;
181 	struct list_head queue;
182 	u8 status;
183 	u32 bpw_len;
184 	u8 transfer_active;
185 	u32 tx_index;
186 	u32 rx_index;
187 	u16 *pkt_tx_buff;
188 	u16 *pkt_rx_buff;
189 	u8 n_curnt_chip;
190 	struct spi_device *current_chip;
191 	struct spi_message *current_msg;
192 	struct spi_transfer *cur_trans;
193 	struct pch_spi_board_data *board_dat;
194 	struct platform_device	*plat_dev;
195 	int ch;
196 	struct pch_spi_dma_ctrl dma;
197 	int use_dma;
198 	u8 irq_reg_sts;
199 };
200 
201 /**
202  * struct pch_spi_board_data - Holds the SPI device specific details
203  * @pdev:		Pointer to the PCI device
204  * @suspend_sts:	Status of suspend
205  * @num:		The number of SPI device instance
206  */
207 struct pch_spi_board_data {
208 	struct pci_dev *pdev;
209 	u8 suspend_sts;
210 	int num;
211 };
212 
213 struct pch_pd_dev_save {
214 	int num;
215 	struct platform_device *pd_save[PCH_SPI_MAX_DEV];
216 	struct pch_spi_board_data *board_dat;
217 };
218 
219 static struct pci_device_id pch_spi_pcidev_id[] = {
220 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_GE_SPI),    1, },
221 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_SPI), 2, },
222 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_SPI), 1, },
223 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_SPI), 1, },
224 	{ }
225 };
226 
227 /**
228  * pch_spi_writereg() - Performs  register writes
229  * @master:	Pointer to struct spi_master.
230  * @idx:	Register offset.
231  * @val:	Value to be written to register.
232  */
233 static inline void pch_spi_writereg(struct spi_master *master, int idx, u32 val)
234 {
235 	struct pch_spi_data *data = spi_master_get_devdata(master);
236 	iowrite32(val, (data->io_remap_addr + idx));
237 }
238 
239 /**
240  * pch_spi_readreg() - Performs register reads
241  * @master:	Pointer to struct spi_master.
242  * @idx:	Register offset.
243  */
244 static inline u32 pch_spi_readreg(struct spi_master *master, int idx)
245 {
246 	struct pch_spi_data *data = spi_master_get_devdata(master);
247 	return ioread32(data->io_remap_addr + idx);
248 }
249 
250 static inline void pch_spi_setclr_reg(struct spi_master *master, int idx,
251 				      u32 set, u32 clr)
252 {
253 	u32 tmp = pch_spi_readreg(master, idx);
254 	tmp = (tmp & ~clr) | set;
255 	pch_spi_writereg(master, idx, tmp);
256 }
257 
258 static void pch_spi_set_master_mode(struct spi_master *master)
259 {
260 	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_MSTR_BIT, 0);
261 }
262 
263 /**
264  * pch_spi_clear_fifo() - Clears the Transmit and Receive FIFOs
265  * @master:	Pointer to struct spi_master.
266  */
267 static void pch_spi_clear_fifo(struct spi_master *master)
268 {
269 	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_FICLR_BIT, 0);
270 	pch_spi_setclr_reg(master, PCH_SPCR, 0, SPCR_FICLR_BIT);
271 }
272 
273 static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
274 				void __iomem *io_remap_addr)
275 {
276 	u32 n_read, tx_index, rx_index, bpw_len;
277 	u16 *pkt_rx_buffer, *pkt_tx_buff;
278 	int read_cnt;
279 	u32 reg_spcr_val;
280 	void __iomem *spsr;
281 	void __iomem *spdrr;
282 	void __iomem *spdwr;
283 
284 	spsr = io_remap_addr + PCH_SPSR;
285 	iowrite32(reg_spsr_val, spsr);
286 
287 	if (data->transfer_active) {
288 		rx_index = data->rx_index;
289 		tx_index = data->tx_index;
290 		bpw_len = data->bpw_len;
291 		pkt_rx_buffer = data->pkt_rx_buff;
292 		pkt_tx_buff = data->pkt_tx_buff;
293 
294 		spdrr = io_remap_addr + PCH_SPDRR;
295 		spdwr = io_remap_addr + PCH_SPDWR;
296 
297 		n_read = PCH_READABLE(reg_spsr_val);
298 
299 		for (read_cnt = 0; (read_cnt < n_read); read_cnt++) {
300 			pkt_rx_buffer[rx_index++] = ioread32(spdrr);
301 			if (tx_index < bpw_len)
302 				iowrite32(pkt_tx_buff[tx_index++], spdwr);
303 		}
304 
305 		/* disable RFI if not needed */
306 		if ((bpw_len - rx_index) <= PCH_MAX_FIFO_DEPTH) {
307 			reg_spcr_val = ioread32(io_remap_addr + PCH_SPCR);
308 			reg_spcr_val &= ~SPCR_RFIE_BIT; /* disable RFI */
309 
310 			/* reset rx threshold */
311 			reg_spcr_val &= ~MASK_RFIC_SPCR_BITS;
312 			reg_spcr_val |= (PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD);
313 
314 			iowrite32(reg_spcr_val, (io_remap_addr + PCH_SPCR));
315 		}
316 
317 		/* update counts */
318 		data->tx_index = tx_index;
319 		data->rx_index = rx_index;
320 
321 	}
322 
323 	/* if transfer complete interrupt */
324 	if (reg_spsr_val & SPSR_FI_BIT) {
325 		if ((tx_index == bpw_len) && (rx_index == tx_index)) {
326 			/* disable interrupts */
327 			pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
328 
329 			/* transfer is completed;
330 			   inform pch_spi_process_messages */
331 			data->transfer_complete = true;
332 			data->transfer_active = false;
333 			wake_up(&data->wait);
334 		} else {
335 			dev_err(&data->master->dev,
336 				"%s : Transfer is not completed", __func__);
337 		}
338 	}
339 }
340 
341 /**
342  * pch_spi_handler() - Interrupt handler
343  * @irq:	The interrupt number.
344  * @dev_id:	Pointer to struct pch_spi_board_data.
345  */
346 static irqreturn_t pch_spi_handler(int irq, void *dev_id)
347 {
348 	u32 reg_spsr_val;
349 	void __iomem *spsr;
350 	void __iomem *io_remap_addr;
351 	irqreturn_t ret = IRQ_NONE;
352 	struct pch_spi_data *data = dev_id;
353 	struct pch_spi_board_data *board_dat = data->board_dat;
354 
355 	if (board_dat->suspend_sts) {
356 		dev_dbg(&board_dat->pdev->dev,
357 			"%s returning due to suspend\n", __func__);
358 		return IRQ_NONE;
359 	}
360 
361 	io_remap_addr = data->io_remap_addr;
362 	spsr = io_remap_addr + PCH_SPSR;
363 
364 	reg_spsr_val = ioread32(spsr);
365 
366 	if (reg_spsr_val & SPSR_ORF_BIT) {
367 		dev_err(&board_dat->pdev->dev, "%s Over run error\n", __func__);
368 		if (data->current_msg->complete != 0) {
369 			data->transfer_complete = true;
370 			data->current_msg->status = -EIO;
371 			data->current_msg->complete(data->current_msg->context);
372 			data->bcurrent_msg_processing = false;
373 			data->current_msg = NULL;
374 			data->cur_trans = NULL;
375 		}
376 	}
377 
378 	if (data->use_dma)
379 		return IRQ_NONE;
380 
381 	/* Check if the interrupt is for SPI device */
382 	if (reg_spsr_val & (SPSR_FI_BIT | SPSR_RFI_BIT)) {
383 		pch_spi_handler_sub(data, reg_spsr_val, io_remap_addr);
384 		ret = IRQ_HANDLED;
385 	}
386 
387 	dev_dbg(&board_dat->pdev->dev, "%s EXIT return value=%d\n",
388 		__func__, ret);
389 
390 	return ret;
391 }
392 
393 /**
394  * pch_spi_set_baud_rate() - Sets SPBR field in SPBRR
395  * @master:	Pointer to struct spi_master.
396  * @speed_hz:	Baud rate.
397  */
398 static void pch_spi_set_baud_rate(struct spi_master *master, u32 speed_hz)
399 {
400 	u32 n_spbr = PCH_CLOCK_HZ / (speed_hz * 2);
401 
402 	/* if baud rate is less than we can support limit it */
403 	if (n_spbr > PCH_MAX_SPBR)
404 		n_spbr = PCH_MAX_SPBR;
405 
406 	pch_spi_setclr_reg(master, PCH_SPBRR, n_spbr, MASK_SPBRR_SPBR_BITS);
407 }
408 
409 /**
410  * pch_spi_set_bits_per_word() - Sets SIZE field in SPBRR
411  * @master:		Pointer to struct spi_master.
412  * @bits_per_word:	Bits per word for SPI transfer.
413  */
414 static void pch_spi_set_bits_per_word(struct spi_master *master,
415 				      u8 bits_per_word)
416 {
417 	if (bits_per_word == 8)
418 		pch_spi_setclr_reg(master, PCH_SPBRR, 0, SPBRR_SIZE_BIT);
419 	else
420 		pch_spi_setclr_reg(master, PCH_SPBRR, SPBRR_SIZE_BIT, 0);
421 }
422 
423 /**
424  * pch_spi_setup_transfer() - Configures the PCH SPI hardware for transfer
425  * @spi:	Pointer to struct spi_device.
426  */
427 static void pch_spi_setup_transfer(struct spi_device *spi)
428 {
429 	u32 flags = 0;
430 
431 	dev_dbg(&spi->dev, "%s SPBRR content =%x setting baud rate=%d\n",
432 		__func__, pch_spi_readreg(spi->master, PCH_SPBRR),
433 		spi->max_speed_hz);
434 	pch_spi_set_baud_rate(spi->master, spi->max_speed_hz);
435 
436 	/* set bits per word */
437 	pch_spi_set_bits_per_word(spi->master, spi->bits_per_word);
438 
439 	if (!(spi->mode & SPI_LSB_FIRST))
440 		flags |= SPCR_LSBF_BIT;
441 	if (spi->mode & SPI_CPOL)
442 		flags |= SPCR_CPOL_BIT;
443 	if (spi->mode & SPI_CPHA)
444 		flags |= SPCR_CPHA_BIT;
445 	pch_spi_setclr_reg(spi->master, PCH_SPCR, flags,
446 			   (SPCR_LSBF_BIT | SPCR_CPOL_BIT | SPCR_CPHA_BIT));
447 
448 	/* Clear the FIFO by toggling  FICLR to 1 and back to 0 */
449 	pch_spi_clear_fifo(spi->master);
450 }
451 
452 /**
453  * pch_spi_reset() - Clears SPI registers
454  * @master:	Pointer to struct spi_master.
455  */
456 static void pch_spi_reset(struct spi_master *master)
457 {
458 	/* write 1 to reset SPI */
459 	pch_spi_writereg(master, PCH_SRST, 0x1);
460 
461 	/* clear reset */
462 	pch_spi_writereg(master, PCH_SRST, 0x0);
463 }
464 
465 static int pch_spi_setup(struct spi_device *pspi)
466 {
467 	/* check bits per word */
468 	if (pspi->bits_per_word == 0) {
469 		pspi->bits_per_word = 8;
470 		dev_dbg(&pspi->dev, "%s 8 bits per word\n", __func__);
471 	}
472 
473 	if ((pspi->bits_per_word != 8) && (pspi->bits_per_word != 16)) {
474 		dev_err(&pspi->dev, "%s Invalid bits per word\n", __func__);
475 		return -EINVAL;
476 	}
477 
478 	/* Check baud rate setting */
479 	/* if baud rate of chip is greater than
480 	   max we can support,return error */
481 	if ((pspi->max_speed_hz) > PCH_MAX_BAUDRATE)
482 		pspi->max_speed_hz = PCH_MAX_BAUDRATE;
483 
484 	dev_dbg(&pspi->dev, "%s MODE = %x\n", __func__,
485 		(pspi->mode) & (SPI_CPOL | SPI_CPHA));
486 
487 	return 0;
488 }
489 
490 static int pch_spi_transfer(struct spi_device *pspi, struct spi_message *pmsg)
491 {
492 
493 	struct spi_transfer *transfer;
494 	struct pch_spi_data *data = spi_master_get_devdata(pspi->master);
495 	int retval;
496 	unsigned long flags;
497 
498 	/* validate spi message and baud rate */
499 	if (unlikely(list_empty(&pmsg->transfers) == 1)) {
500 		dev_err(&pspi->dev, "%s list empty\n", __func__);
501 		retval = -EINVAL;
502 		goto err_out;
503 	}
504 
505 	if (unlikely(pspi->max_speed_hz == 0)) {
506 		dev_err(&pspi->dev, "%s pch_spi_tranfer maxspeed=%d\n",
507 			__func__, pspi->max_speed_hz);
508 		retval = -EINVAL;
509 		goto err_out;
510 	}
511 
512 	dev_dbg(&pspi->dev, "%s Transfer List not empty. "
513 		"Transfer Speed is set.\n", __func__);
514 
515 	spin_lock_irqsave(&data->lock, flags);
516 	/* validate Tx/Rx buffers and Transfer length */
517 	list_for_each_entry(transfer, &pmsg->transfers, transfer_list) {
518 		if (!transfer->tx_buf && !transfer->rx_buf) {
519 			dev_err(&pspi->dev,
520 				"%s Tx and Rx buffer NULL\n", __func__);
521 			retval = -EINVAL;
522 			goto err_return_spinlock;
523 		}
524 
525 		if (!transfer->len) {
526 			dev_err(&pspi->dev, "%s Transfer length invalid\n",
527 				__func__);
528 			retval = -EINVAL;
529 			goto err_return_spinlock;
530 		}
531 
532 		dev_dbg(&pspi->dev, "%s Tx/Rx buffer valid. Transfer length"
533 			" valid\n", __func__);
534 
535 		/* if baud rate has been specified validate the same */
536 		if (transfer->speed_hz > PCH_MAX_BAUDRATE)
537 			transfer->speed_hz = PCH_MAX_BAUDRATE;
538 
539 		/* if bits per word has been specified validate the same */
540 		if (transfer->bits_per_word) {
541 			if ((transfer->bits_per_word != 8)
542 			    && (transfer->bits_per_word != 16)) {
543 				retval = -EINVAL;
544 				dev_err(&pspi->dev,
545 					"%s Invalid bits per word\n", __func__);
546 				goto err_return_spinlock;
547 			}
548 		}
549 	}
550 	spin_unlock_irqrestore(&data->lock, flags);
551 
552 	/* We won't process any messages if we have been asked to terminate */
553 	if (data->status == STATUS_EXITING) {
554 		dev_err(&pspi->dev, "%s status = STATUS_EXITING.\n", __func__);
555 		retval = -ESHUTDOWN;
556 		goto err_out;
557 	}
558 
559 	/* If suspended ,return -EINVAL */
560 	if (data->board_dat->suspend_sts) {
561 		dev_err(&pspi->dev, "%s suspend; returning EINVAL\n", __func__);
562 		retval = -EINVAL;
563 		goto err_out;
564 	}
565 
566 	/* set status of message */
567 	pmsg->actual_length = 0;
568 	dev_dbg(&pspi->dev, "%s - pmsg->status =%d\n", __func__, pmsg->status);
569 
570 	pmsg->status = -EINPROGRESS;
571 	spin_lock_irqsave(&data->lock, flags);
572 	/* add message to queue */
573 	list_add_tail(&pmsg->queue, &data->queue);
574 	spin_unlock_irqrestore(&data->lock, flags);
575 
576 	dev_dbg(&pspi->dev, "%s - Invoked list_add_tail\n", __func__);
577 
578 	/* schedule work queue to run */
579 	queue_work(data->wk, &data->work);
580 	dev_dbg(&pspi->dev, "%s - Invoked queue work\n", __func__);
581 
582 	retval = 0;
583 
584 err_out:
585 	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
586 	return retval;
587 err_return_spinlock:
588 	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
589 	spin_unlock_irqrestore(&data->lock, flags);
590 	return retval;
591 }
592 
593 static inline void pch_spi_select_chip(struct pch_spi_data *data,
594 				       struct spi_device *pspi)
595 {
596 	if (data->current_chip != NULL) {
597 		if (pspi->chip_select != data->n_curnt_chip) {
598 			dev_dbg(&pspi->dev, "%s : different slave\n", __func__);
599 			data->current_chip = NULL;
600 		}
601 	}
602 
603 	data->current_chip = pspi;
604 
605 	data->n_curnt_chip = data->current_chip->chip_select;
606 
607 	dev_dbg(&pspi->dev, "%s :Invoking pch_spi_setup_transfer\n", __func__);
608 	pch_spi_setup_transfer(pspi);
609 }
610 
611 static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)
612 {
613 	int size;
614 	u32 n_writes;
615 	int j;
616 	struct spi_message *pmsg;
617 	const u8 *tx_buf;
618 	const u16 *tx_sbuf;
619 
620 	/* set baud rate if needed */
621 	if (data->cur_trans->speed_hz) {
622 		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
623 		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
624 	}
625 
626 	/* set bits per word if needed */
627 	if (data->cur_trans->bits_per_word &&
628 	    (data->current_msg->spi->bits_per_word != data->cur_trans->bits_per_word)) {
629 		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
630 		pch_spi_set_bits_per_word(data->master,
631 					  data->cur_trans->bits_per_word);
632 		*bpw = data->cur_trans->bits_per_word;
633 	} else {
634 		*bpw = data->current_msg->spi->bits_per_word;
635 	}
636 
637 	/* reset Tx/Rx index */
638 	data->tx_index = 0;
639 	data->rx_index = 0;
640 
641 	data->bpw_len = data->cur_trans->len / (*bpw / 8);
642 
643 	/* find alloc size */
644 	size = data->cur_trans->len * sizeof(*data->pkt_tx_buff);
645 
646 	/* allocate memory for pkt_tx_buff & pkt_rx_buffer */
647 	data->pkt_tx_buff = kzalloc(size, GFP_KERNEL);
648 	if (data->pkt_tx_buff != NULL) {
649 		data->pkt_rx_buff = kzalloc(size, GFP_KERNEL);
650 		if (!data->pkt_rx_buff)
651 			kfree(data->pkt_tx_buff);
652 	}
653 
654 	if (!data->pkt_rx_buff) {
655 		/* flush queue and set status of all transfers to -ENOMEM */
656 		dev_err(&data->master->dev, "%s :kzalloc failed\n", __func__);
657 		list_for_each_entry(pmsg, data->queue.next, queue) {
658 			pmsg->status = -ENOMEM;
659 
660 			if (pmsg->complete != 0)
661 				pmsg->complete(pmsg->context);
662 
663 			/* delete from queue */
664 			list_del_init(&pmsg->queue);
665 		}
666 		return;
667 	}
668 
669 	/* copy Tx Data */
670 	if (data->cur_trans->tx_buf != NULL) {
671 		if (*bpw == 8) {
672 			tx_buf = data->cur_trans->tx_buf;
673 			for (j = 0; j < data->bpw_len; j++)
674 				data->pkt_tx_buff[j] = *tx_buf++;
675 		} else {
676 			tx_sbuf = data->cur_trans->tx_buf;
677 			for (j = 0; j < data->bpw_len; j++)
678 				data->pkt_tx_buff[j] = *tx_sbuf++;
679 		}
680 	}
681 
682 	/* if len greater than PCH_MAX_FIFO_DEPTH, write 16,else len bytes */
683 	n_writes = data->bpw_len;
684 	if (n_writes > PCH_MAX_FIFO_DEPTH)
685 		n_writes = PCH_MAX_FIFO_DEPTH;
686 
687 	dev_dbg(&data->master->dev, "\n%s:Pulling down SSN low - writing "
688 		"0x2 to SSNXCR\n", __func__);
689 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
690 
691 	for (j = 0; j < n_writes; j++)
692 		pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
693 
694 	/* update tx_index */
695 	data->tx_index = j;
696 
697 	/* reset transfer complete flag */
698 	data->transfer_complete = false;
699 	data->transfer_active = true;
700 }
701 
702 static void pch_spi_nomore_transfer(struct pch_spi_data *data)
703 {
704 	struct spi_message *pmsg;
705 	dev_dbg(&data->master->dev, "%s called\n", __func__);
706 	/* Invoke complete callback
707 	 * [To the spi core..indicating end of transfer] */
708 	data->current_msg->status = 0;
709 
710 	if (data->current_msg->complete != 0) {
711 		dev_dbg(&data->master->dev,
712 			"%s:Invoking callback of SPI core\n", __func__);
713 		data->current_msg->complete(data->current_msg->context);
714 	}
715 
716 	/* update status in global variable */
717 	data->bcurrent_msg_processing = false;
718 
719 	dev_dbg(&data->master->dev,
720 		"%s:data->bcurrent_msg_processing = false\n", __func__);
721 
722 	data->current_msg = NULL;
723 	data->cur_trans = NULL;
724 
725 	/* check if we have items in list and not suspending
726 	 * return 1 if list empty */
727 	if ((list_empty(&data->queue) == 0) &&
728 	    (!data->board_dat->suspend_sts) &&
729 	    (data->status != STATUS_EXITING)) {
730 		/* We have some more work to do (either there is more tranint
731 		 * bpw;sfer requests in the current message or there are
732 		 *more messages)
733 		 */
734 		dev_dbg(&data->master->dev, "%s:Invoke queue_work\n", __func__);
735 		queue_work(data->wk, &data->work);
736 	} else if (data->board_dat->suspend_sts ||
737 		   data->status == STATUS_EXITING) {
738 		dev_dbg(&data->master->dev,
739 			"%s suspend/remove initiated, flushing queue\n",
740 			__func__);
741 		list_for_each_entry(pmsg, data->queue.next, queue) {
742 			pmsg->status = -EIO;
743 
744 			if (pmsg->complete)
745 				pmsg->complete(pmsg->context);
746 
747 			/* delete from queue */
748 			list_del_init(&pmsg->queue);
749 		}
750 	}
751 }
752 
753 static void pch_spi_set_ir(struct pch_spi_data *data)
754 {
755 	/* enable interrupts, set threshold, enable SPI */
756 	if ((data->bpw_len) > PCH_MAX_FIFO_DEPTH)
757 		/* set receive threshold to PCH_RX_THOLD */
758 		pch_spi_setclr_reg(data->master, PCH_SPCR,
759 				   PCH_RX_THOLD << SPCR_RFIC_FIELD |
760 				   SPCR_FIE_BIT | SPCR_RFIE_BIT |
761 				   SPCR_ORIE_BIT | SPCR_SPE_BIT,
762 				   MASK_RFIC_SPCR_BITS | PCH_ALL);
763 	else
764 		/* set receive threshold to maximum */
765 		pch_spi_setclr_reg(data->master, PCH_SPCR,
766 				   PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD |
767 				   SPCR_FIE_BIT | SPCR_ORIE_BIT |
768 				   SPCR_SPE_BIT,
769 				   MASK_RFIC_SPCR_BITS | PCH_ALL);
770 
771 	/* Wait until the transfer completes; go to sleep after
772 				 initiating the transfer. */
773 	dev_dbg(&data->master->dev,
774 		"%s:waiting for transfer to get over\n", __func__);
775 
776 	wait_event_interruptible(data->wait, data->transfer_complete);
777 
778 	/* clear all interrupts */
779 	pch_spi_writereg(data->master, PCH_SPSR,
780 			 pch_spi_readreg(data->master, PCH_SPSR));
781 	/* Disable interrupts and SPI transfer */
782 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL | SPCR_SPE_BIT);
783 	/* clear FIFO */
784 	pch_spi_clear_fifo(data->master);
785 }
786 
787 static void pch_spi_copy_rx_data(struct pch_spi_data *data, int bpw)
788 {
789 	int j;
790 	u8 *rx_buf;
791 	u16 *rx_sbuf;
792 
793 	/* copy Rx Data */
794 	if (!data->cur_trans->rx_buf)
795 		return;
796 
797 	if (bpw == 8) {
798 		rx_buf = data->cur_trans->rx_buf;
799 		for (j = 0; j < data->bpw_len; j++)
800 			*rx_buf++ = data->pkt_rx_buff[j] & 0xFF;
801 	} else {
802 		rx_sbuf = data->cur_trans->rx_buf;
803 		for (j = 0; j < data->bpw_len; j++)
804 			*rx_sbuf++ = data->pkt_rx_buff[j];
805 	}
806 }
807 
808 static void pch_spi_copy_rx_data_for_dma(struct pch_spi_data *data, int bpw)
809 {
810 	int j;
811 	u8 *rx_buf;
812 	u16 *rx_sbuf;
813 	const u8 *rx_dma_buf;
814 	const u16 *rx_dma_sbuf;
815 
816 	/* copy Rx Data */
817 	if (!data->cur_trans->rx_buf)
818 		return;
819 
820 	if (bpw == 8) {
821 		rx_buf = data->cur_trans->rx_buf;
822 		rx_dma_buf = data->dma.rx_buf_virt;
823 		for (j = 0; j < data->bpw_len; j++)
824 			*rx_buf++ = *rx_dma_buf++ & 0xFF;
825 	} else {
826 		rx_sbuf = data->cur_trans->rx_buf;
827 		rx_dma_sbuf = data->dma.rx_buf_virt;
828 		for (j = 0; j < data->bpw_len; j++)
829 			*rx_sbuf++ = *rx_dma_sbuf++;
830 	}
831 }
832 
833 static int pch_spi_start_transfer(struct pch_spi_data *data)
834 {
835 	struct pch_spi_dma_ctrl *dma;
836 	unsigned long flags;
837 	int rtn;
838 
839 	dma = &data->dma;
840 
841 	spin_lock_irqsave(&data->lock, flags);
842 
843 	/* disable interrupts, SPI set enable */
844 	pch_spi_setclr_reg(data->master, PCH_SPCR, SPCR_SPE_BIT, PCH_ALL);
845 
846 	spin_unlock_irqrestore(&data->lock, flags);
847 
848 	/* Wait until the transfer completes; go to sleep after
849 				 initiating the transfer. */
850 	dev_dbg(&data->master->dev,
851 		"%s:waiting for transfer to get over\n", __func__);
852 	rtn = wait_event_interruptible_timeout(data->wait,
853 					       data->transfer_complete,
854 					       msecs_to_jiffies(2 * HZ));
855 
856 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
857 			    DMA_FROM_DEVICE);
858 
859 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_tx_p, dma->nent,
860 			    DMA_FROM_DEVICE);
861 	memset(data->dma.tx_buf_virt, 0, PAGE_SIZE);
862 
863 	async_tx_ack(dma->desc_rx);
864 	async_tx_ack(dma->desc_tx);
865 	kfree(dma->sg_tx_p);
866 	kfree(dma->sg_rx_p);
867 
868 	spin_lock_irqsave(&data->lock, flags);
869 
870 	/* clear fifo threshold, disable interrupts, disable SPI transfer */
871 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
872 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS | PCH_ALL |
873 			   SPCR_SPE_BIT);
874 	/* clear all interrupts */
875 	pch_spi_writereg(data->master, PCH_SPSR,
876 			 pch_spi_readreg(data->master, PCH_SPSR));
877 	/* clear FIFO */
878 	pch_spi_clear_fifo(data->master);
879 
880 	spin_unlock_irqrestore(&data->lock, flags);
881 
882 	return rtn;
883 }
884 
885 static void pch_dma_rx_complete(void *arg)
886 {
887 	struct pch_spi_data *data = arg;
888 
889 	/* transfer is completed;inform pch_spi_process_messages_dma */
890 	data->transfer_complete = true;
891 	wake_up_interruptible(&data->wait);
892 }
893 
894 static bool pch_spi_filter(struct dma_chan *chan, void *slave)
895 {
896 	struct pch_dma_slave *param = slave;
897 
898 	if ((chan->chan_id == param->chan_id) &&
899 	    (param->dma_dev == chan->device->dev)) {
900 		chan->private = param;
901 		return true;
902 	} else {
903 		return false;
904 	}
905 }
906 
907 static void pch_spi_request_dma(struct pch_spi_data *data, int bpw)
908 {
909 	dma_cap_mask_t mask;
910 	struct dma_chan *chan;
911 	struct pci_dev *dma_dev;
912 	struct pch_dma_slave *param;
913 	struct pch_spi_dma_ctrl *dma;
914 	unsigned int width;
915 
916 	if (bpw == 8)
917 		width = PCH_DMA_WIDTH_1_BYTE;
918 	else
919 		width = PCH_DMA_WIDTH_2_BYTES;
920 
921 	dma = &data->dma;
922 	dma_cap_zero(mask);
923 	dma_cap_set(DMA_SLAVE, mask);
924 
925 	/* Get DMA's dev information */
926 	dma_dev = pci_get_bus_and_slot(2, PCI_DEVFN(12, 0));
927 
928 	/* Set Tx DMA */
929 	param = &dma->param_tx;
930 	param->dma_dev = &dma_dev->dev;
931 	param->chan_id = data->master->bus_num * 2; /* Tx = 0, 2 */
932 	param->tx_reg = data->io_base_addr + PCH_SPDWR;
933 	param->width = width;
934 	chan = dma_request_channel(mask, pch_spi_filter, param);
935 	if (!chan) {
936 		dev_err(&data->master->dev,
937 			"ERROR: dma_request_channel FAILS(Tx)\n");
938 		data->use_dma = 0;
939 		return;
940 	}
941 	dma->chan_tx = chan;
942 
943 	/* Set Rx DMA */
944 	param = &dma->param_rx;
945 	param->dma_dev = &dma_dev->dev;
946 	param->chan_id = data->master->bus_num * 2 + 1; /* Rx = Tx + 1 */
947 	param->rx_reg = data->io_base_addr + PCH_SPDRR;
948 	param->width = width;
949 	chan = dma_request_channel(mask, pch_spi_filter, param);
950 	if (!chan) {
951 		dev_err(&data->master->dev,
952 			"ERROR: dma_request_channel FAILS(Rx)\n");
953 		dma_release_channel(dma->chan_tx);
954 		dma->chan_tx = NULL;
955 		data->use_dma = 0;
956 		return;
957 	}
958 	dma->chan_rx = chan;
959 }
960 
961 static void pch_spi_release_dma(struct pch_spi_data *data)
962 {
963 	struct pch_spi_dma_ctrl *dma;
964 
965 	dma = &data->dma;
966 	if (dma->chan_tx) {
967 		dma_release_channel(dma->chan_tx);
968 		dma->chan_tx = NULL;
969 	}
970 	if (dma->chan_rx) {
971 		dma_release_channel(dma->chan_rx);
972 		dma->chan_rx = NULL;
973 	}
974 	return;
975 }
976 
977 static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
978 {
979 	const u8 *tx_buf;
980 	const u16 *tx_sbuf;
981 	u8 *tx_dma_buf;
982 	u16 *tx_dma_sbuf;
983 	struct scatterlist *sg;
984 	struct dma_async_tx_descriptor *desc_tx;
985 	struct dma_async_tx_descriptor *desc_rx;
986 	int num;
987 	int i;
988 	int size;
989 	int rem;
990 	unsigned long flags;
991 	struct pch_spi_dma_ctrl *dma;
992 
993 	dma = &data->dma;
994 
995 	/* set baud rate if needed */
996 	if (data->cur_trans->speed_hz) {
997 		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
998 		spin_lock_irqsave(&data->lock, flags);
999 		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
1000 		spin_unlock_irqrestore(&data->lock, flags);
1001 	}
1002 
1003 	/* set bits per word if needed */
1004 	if (data->cur_trans->bits_per_word &&
1005 	    (data->current_msg->spi->bits_per_word !=
1006 	     data->cur_trans->bits_per_word)) {
1007 		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
1008 		spin_lock_irqsave(&data->lock, flags);
1009 		pch_spi_set_bits_per_word(data->master,
1010 					  data->cur_trans->bits_per_word);
1011 		spin_unlock_irqrestore(&data->lock, flags);
1012 		*bpw = data->cur_trans->bits_per_word;
1013 	} else {
1014 		*bpw = data->current_msg->spi->bits_per_word;
1015 	}
1016 	data->bpw_len = data->cur_trans->len / (*bpw / 8);
1017 
1018 	/* copy Tx Data */
1019 	if (data->cur_trans->tx_buf != NULL) {
1020 		if (*bpw == 8) {
1021 			tx_buf = data->cur_trans->tx_buf;
1022 			tx_dma_buf = dma->tx_buf_virt;
1023 			for (i = 0; i < data->bpw_len; i++)
1024 				*tx_dma_buf++ = *tx_buf++;
1025 		} else {
1026 			tx_sbuf = data->cur_trans->tx_buf;
1027 			tx_dma_sbuf = dma->tx_buf_virt;
1028 			for (i = 0; i < data->bpw_len; i++)
1029 				*tx_dma_sbuf++ = *tx_sbuf++;
1030 		}
1031 	}
1032 	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
1033 		num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
1034 		size = PCH_DMA_TRANS_SIZE;
1035 		rem = data->bpw_len % PCH_DMA_TRANS_SIZE;
1036 	} else {
1037 		num = 1;
1038 		size = data->bpw_len;
1039 		rem = data->bpw_len;
1040 	}
1041 	dev_dbg(&data->master->dev, "%s num=%d size=%d rem=%d\n",
1042 		__func__, num, size, rem);
1043 	spin_lock_irqsave(&data->lock, flags);
1044 
1045 	/* set receive fifo threshold and transmit fifo threshold */
1046 	pch_spi_setclr_reg(data->master, PCH_SPCR,
1047 			   ((size - 1) << SPCR_RFIC_FIELD) |
1048 			   (PCH_TX_THOLD << SPCR_TFIC_FIELD),
1049 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS);
1050 
1051 	spin_unlock_irqrestore(&data->lock, flags);
1052 
1053 	/* RX */
1054 	dma->sg_rx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
1055 	sg_init_table(dma->sg_rx_p, num); /* Initialize SG table */
1056 	/* offset, length setting */
1057 	sg = dma->sg_rx_p;
1058 	for (i = 0; i < num; i++, sg++) {
1059 		if (i == (num - 2)) {
1060 			sg->offset = size * i;
1061 			sg->offset = sg->offset * (*bpw / 8);
1062 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), rem,
1063 				    sg->offset);
1064 			sg_dma_len(sg) = rem;
1065 		} else if (i == (num - 1)) {
1066 			sg->offset = size * (i - 1) + rem;
1067 			sg->offset = sg->offset * (*bpw / 8);
1068 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
1069 				    sg->offset);
1070 			sg_dma_len(sg) = size;
1071 		} else {
1072 			sg->offset = size * i;
1073 			sg->offset = sg->offset * (*bpw / 8);
1074 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
1075 				    sg->offset);
1076 			sg_dma_len(sg) = size;
1077 		}
1078 		sg_dma_address(sg) = dma->rx_buf_dma + sg->offset;
1079 	}
1080 	sg = dma->sg_rx_p;
1081 	desc_rx = dma->chan_rx->device->device_prep_slave_sg(dma->chan_rx, sg,
1082 					num, DMA_DEV_TO_MEM,
1083 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1084 	if (!desc_rx) {
1085 		dev_err(&data->master->dev, "%s:device_prep_slave_sg Failed\n",
1086 			__func__);
1087 		return;
1088 	}
1089 	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_FROM_DEVICE);
1090 	desc_rx->callback = pch_dma_rx_complete;
1091 	desc_rx->callback_param = data;
1092 	dma->nent = num;
1093 	dma->desc_rx = desc_rx;
1094 
1095 	/* TX */
1096 	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
1097 		num = data->bpw_len / PCH_DMA_TRANS_SIZE;
1098 		size = PCH_DMA_TRANS_SIZE;
1099 		rem = 16;
1100 	} else {
1101 		num = 1;
1102 		size = data->bpw_len;
1103 		rem = data->bpw_len;
1104 	}
1105 
1106 	dma->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
1107 	sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */
1108 	/* offset, length setting */
1109 	sg = dma->sg_tx_p;
1110 	for (i = 0; i < num; i++, sg++) {
1111 		if (i == 0) {
1112 			sg->offset = 0;
1113 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), rem,
1114 				    sg->offset);
1115 			sg_dma_len(sg) = rem;
1116 		} else {
1117 			sg->offset = rem + size * (i - 1);
1118 			sg->offset = sg->offset * (*bpw / 8);
1119 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size,
1120 				    sg->offset);
1121 			sg_dma_len(sg) = size;
1122 		}
1123 		sg_dma_address(sg) = dma->tx_buf_dma + sg->offset;
1124 	}
1125 	sg = dma->sg_tx_p;
1126 	desc_tx = dma->chan_tx->device->device_prep_slave_sg(dma->chan_tx,
1127 					sg, num, DMA_MEM_TO_DEV,
1128 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1129 	if (!desc_tx) {
1130 		dev_err(&data->master->dev, "%s:device_prep_slave_sg Failed\n",
1131 			__func__);
1132 		return;
1133 	}
1134 	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_TO_DEVICE);
1135 	desc_tx->callback = NULL;
1136 	desc_tx->callback_param = data;
1137 	dma->nent = num;
1138 	dma->desc_tx = desc_tx;
1139 
1140 	dev_dbg(&data->master->dev, "\n%s:Pulling down SSN low - writing "
1141 		"0x2 to SSNXCR\n", __func__);
1142 
1143 	spin_lock_irqsave(&data->lock, flags);
1144 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
1145 	desc_rx->tx_submit(desc_rx);
1146 	desc_tx->tx_submit(desc_tx);
1147 	spin_unlock_irqrestore(&data->lock, flags);
1148 
1149 	/* reset transfer complete flag */
1150 	data->transfer_complete = false;
1151 }
1152 
1153 static void pch_spi_process_messages(struct work_struct *pwork)
1154 {
1155 	struct spi_message *pmsg;
1156 	struct pch_spi_data *data;
1157 	int bpw;
1158 
1159 	data = container_of(pwork, struct pch_spi_data, work);
1160 	dev_dbg(&data->master->dev, "%s data initialized\n", __func__);
1161 
1162 	spin_lock(&data->lock);
1163 	/* check if suspend has been initiated;if yes flush queue */
1164 	if (data->board_dat->suspend_sts || (data->status == STATUS_EXITING)) {
1165 		dev_dbg(&data->master->dev, "%s suspend/remove initiated,"
1166 			"flushing queue\n", __func__);
1167 		list_for_each_entry(pmsg, data->queue.next, queue) {
1168 			pmsg->status = -EIO;
1169 
1170 			if (pmsg->complete != 0) {
1171 				spin_unlock(&data->lock);
1172 				pmsg->complete(pmsg->context);
1173 				spin_lock(&data->lock);
1174 			}
1175 
1176 			/* delete from queue */
1177 			list_del_init(&pmsg->queue);
1178 		}
1179 
1180 		spin_unlock(&data->lock);
1181 		return;
1182 	}
1183 
1184 	data->bcurrent_msg_processing = true;
1185 	dev_dbg(&data->master->dev,
1186 		"%s Set data->bcurrent_msg_processing= true\n", __func__);
1187 
1188 	/* Get the message from the queue and delete it from there. */
1189 	data->current_msg = list_entry(data->queue.next, struct spi_message,
1190 					queue);
1191 
1192 	list_del_init(&data->current_msg->queue);
1193 
1194 	data->current_msg->status = 0;
1195 
1196 	pch_spi_select_chip(data, data->current_msg->spi);
1197 
1198 	spin_unlock(&data->lock);
1199 
1200 	if (data->use_dma)
1201 		pch_spi_request_dma(data,
1202 				    data->current_msg->spi->bits_per_word);
1203 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
1204 	do {
1205 		/* If we are already processing a message get the next
1206 		transfer structure from the message otherwise retrieve
1207 		the 1st transfer request from the message. */
1208 		spin_lock(&data->lock);
1209 		if (data->cur_trans == NULL) {
1210 			data->cur_trans =
1211 				list_entry(data->current_msg->transfers.next,
1212 					   struct spi_transfer, transfer_list);
1213 			dev_dbg(&data->master->dev, "%s "
1214 				":Getting 1st transfer message\n", __func__);
1215 		} else {
1216 			data->cur_trans =
1217 				list_entry(data->cur_trans->transfer_list.next,
1218 					   struct spi_transfer, transfer_list);
1219 			dev_dbg(&data->master->dev, "%s "
1220 				":Getting next transfer message\n", __func__);
1221 		}
1222 		spin_unlock(&data->lock);
1223 
1224 		if (data->use_dma) {
1225 			pch_spi_handle_dma(data, &bpw);
1226 			if (!pch_spi_start_transfer(data))
1227 				goto out;
1228 			pch_spi_copy_rx_data_for_dma(data, bpw);
1229 		} else {
1230 			pch_spi_set_tx(data, &bpw);
1231 			pch_spi_set_ir(data);
1232 			pch_spi_copy_rx_data(data, bpw);
1233 			kfree(data->pkt_rx_buff);
1234 			data->pkt_rx_buff = NULL;
1235 			kfree(data->pkt_tx_buff);
1236 			data->pkt_tx_buff = NULL;
1237 		}
1238 		/* increment message count */
1239 		data->current_msg->actual_length += data->cur_trans->len;
1240 
1241 		dev_dbg(&data->master->dev,
1242 			"%s:data->current_msg->actual_length=%d\n",
1243 			__func__, data->current_msg->actual_length);
1244 
1245 		/* check for delay */
1246 		if (data->cur_trans->delay_usecs) {
1247 			dev_dbg(&data->master->dev, "%s:"
1248 				"delay in usec=%d\n", __func__,
1249 				data->cur_trans->delay_usecs);
1250 			udelay(data->cur_trans->delay_usecs);
1251 		}
1252 
1253 		spin_lock(&data->lock);
1254 
1255 		/* No more transfer in this message. */
1256 		if ((data->cur_trans->transfer_list.next) ==
1257 		    &(data->current_msg->transfers)) {
1258 			pch_spi_nomore_transfer(data);
1259 		}
1260 
1261 		spin_unlock(&data->lock);
1262 
1263 	} while (data->cur_trans != NULL);
1264 
1265 out:
1266 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_HIGH);
1267 	if (data->use_dma)
1268 		pch_spi_release_dma(data);
1269 }
1270 
1271 static void pch_spi_free_resources(struct pch_spi_board_data *board_dat,
1272 				   struct pch_spi_data *data)
1273 {
1274 	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
1275 
1276 	/* free workqueue */
1277 	if (data->wk != NULL) {
1278 		destroy_workqueue(data->wk);
1279 		data->wk = NULL;
1280 		dev_dbg(&board_dat->pdev->dev,
1281 			"%s destroy_workqueue invoked successfully\n",
1282 			__func__);
1283 	}
1284 }
1285 
1286 static int pch_spi_get_resources(struct pch_spi_board_data *board_dat,
1287 				 struct pch_spi_data *data)
1288 {
1289 	int retval = 0;
1290 
1291 	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
1292 
1293 	/* create workqueue */
1294 	data->wk = create_singlethread_workqueue(KBUILD_MODNAME);
1295 	if (!data->wk) {
1296 		dev_err(&board_dat->pdev->dev,
1297 			"%s create_singlet hread_workqueue failed\n", __func__);
1298 		retval = -EBUSY;
1299 		goto err_return;
1300 	}
1301 
1302 	/* reset PCH SPI h/w */
1303 	pch_spi_reset(data->master);
1304 	dev_dbg(&board_dat->pdev->dev,
1305 		"%s pch_spi_reset invoked successfully\n", __func__);
1306 
1307 	dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true\n", __func__);
1308 
1309 err_return:
1310 	if (retval != 0) {
1311 		dev_err(&board_dat->pdev->dev,
1312 			"%s FAIL:invoking pch_spi_free_resources\n", __func__);
1313 		pch_spi_free_resources(board_dat, data);
1314 	}
1315 
1316 	dev_dbg(&board_dat->pdev->dev, "%s Return=%d\n", __func__, retval);
1317 
1318 	return retval;
1319 }
1320 
1321 static void pch_free_dma_buf(struct pch_spi_board_data *board_dat,
1322 			     struct pch_spi_data *data)
1323 {
1324 	struct pch_spi_dma_ctrl *dma;
1325 
1326 	dma = &data->dma;
1327 	if (dma->tx_buf_dma)
1328 		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
1329 				  dma->tx_buf_virt, dma->tx_buf_dma);
1330 	if (dma->rx_buf_dma)
1331 		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
1332 				  dma->rx_buf_virt, dma->rx_buf_dma);
1333 	return;
1334 }
1335 
1336 static void pch_alloc_dma_buf(struct pch_spi_board_data *board_dat,
1337 			      struct pch_spi_data *data)
1338 {
1339 	struct pch_spi_dma_ctrl *dma;
1340 
1341 	dma = &data->dma;
1342 	/* Get Consistent memory for Tx DMA */
1343 	dma->tx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
1344 				PCH_BUF_SIZE, &dma->tx_buf_dma, GFP_KERNEL);
1345 	/* Get Consistent memory for Rx DMA */
1346 	dma->rx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
1347 				PCH_BUF_SIZE, &dma->rx_buf_dma, GFP_KERNEL);
1348 }
1349 
1350 static int __devinit pch_spi_pd_probe(struct platform_device *plat_dev)
1351 {
1352 	int ret;
1353 	struct spi_master *master;
1354 	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
1355 	struct pch_spi_data *data;
1356 
1357 	dev_dbg(&plat_dev->dev, "%s:debug\n", __func__);
1358 
1359 	master = spi_alloc_master(&board_dat->pdev->dev,
1360 				  sizeof(struct pch_spi_data));
1361 	if (!master) {
1362 		dev_err(&plat_dev->dev, "spi_alloc_master[%d] failed.\n",
1363 			plat_dev->id);
1364 		return -ENOMEM;
1365 	}
1366 
1367 	data = spi_master_get_devdata(master);
1368 	data->master = master;
1369 
1370 	platform_set_drvdata(plat_dev, data);
1371 
1372 	/* baseaddress + address offset) */
1373 	data->io_base_addr = pci_resource_start(board_dat->pdev, 1) +
1374 					 PCH_ADDRESS_SIZE * plat_dev->id;
1375 	data->io_remap_addr = pci_iomap(board_dat->pdev, 1, 0) +
1376 					 PCH_ADDRESS_SIZE * plat_dev->id;
1377 	if (!data->io_remap_addr) {
1378 		dev_err(&plat_dev->dev, "%s pci_iomap failed\n", __func__);
1379 		ret = -ENOMEM;
1380 		goto err_pci_iomap;
1381 	}
1382 
1383 	dev_dbg(&plat_dev->dev, "[ch%d] remap_addr=%p\n",
1384 		plat_dev->id, data->io_remap_addr);
1385 
1386 	/* initialize members of SPI master */
1387 	master->bus_num = -1;
1388 	master->num_chipselect = PCH_MAX_CS;
1389 	master->setup = pch_spi_setup;
1390 	master->transfer = pch_spi_transfer;
1391 
1392 	data->board_dat = board_dat;
1393 	data->plat_dev = plat_dev;
1394 	data->n_curnt_chip = 255;
1395 	data->status = STATUS_RUNNING;
1396 	data->ch = plat_dev->id;
1397 	data->use_dma = use_dma;
1398 
1399 	INIT_LIST_HEAD(&data->queue);
1400 	spin_lock_init(&data->lock);
1401 	INIT_WORK(&data->work, pch_spi_process_messages);
1402 	init_waitqueue_head(&data->wait);
1403 
1404 	ret = pch_spi_get_resources(board_dat, data);
1405 	if (ret) {
1406 		dev_err(&plat_dev->dev, "%s fail(retval=%d)\n", __func__, ret);
1407 		goto err_spi_get_resources;
1408 	}
1409 
1410 	ret = request_irq(board_dat->pdev->irq, pch_spi_handler,
1411 			  IRQF_SHARED, KBUILD_MODNAME, data);
1412 	if (ret) {
1413 		dev_err(&plat_dev->dev,
1414 			"%s request_irq failed\n", __func__);
1415 		goto err_request_irq;
1416 	}
1417 	data->irq_reg_sts = true;
1418 
1419 	pch_spi_set_master_mode(master);
1420 
1421 	ret = spi_register_master(master);
1422 	if (ret != 0) {
1423 		dev_err(&plat_dev->dev,
1424 			"%s spi_register_master FAILED\n", __func__);
1425 		goto err_spi_register_master;
1426 	}
1427 
1428 	if (use_dma) {
1429 		dev_info(&plat_dev->dev, "Use DMA for data transfers\n");
1430 		pch_alloc_dma_buf(board_dat, data);
1431 	}
1432 
1433 	return 0;
1434 
1435 err_spi_register_master:
1436 	free_irq(board_dat->pdev->irq, board_dat);
1437 err_request_irq:
1438 	pch_spi_free_resources(board_dat, data);
1439 err_spi_get_resources:
1440 	pci_iounmap(board_dat->pdev, data->io_remap_addr);
1441 err_pci_iomap:
1442 	spi_master_put(master);
1443 
1444 	return ret;
1445 }
1446 
1447 static int __devexit pch_spi_pd_remove(struct platform_device *plat_dev)
1448 {
1449 	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
1450 	struct pch_spi_data *data = platform_get_drvdata(plat_dev);
1451 	int count;
1452 	unsigned long flags;
1453 
1454 	dev_dbg(&plat_dev->dev, "%s:[ch%d] irq=%d\n",
1455 		__func__, plat_dev->id, board_dat->pdev->irq);
1456 
1457 	if (use_dma)
1458 		pch_free_dma_buf(board_dat, data);
1459 
1460 	/* check for any pending messages; no action is taken if the queue
1461 	 * is still full; but at least we tried.  Unload anyway */
1462 	count = 500;
1463 	spin_lock_irqsave(&data->lock, flags);
1464 	data->status = STATUS_EXITING;
1465 	while ((list_empty(&data->queue) == 0) && --count) {
1466 		dev_dbg(&board_dat->pdev->dev, "%s :queue not empty\n",
1467 			__func__);
1468 		spin_unlock_irqrestore(&data->lock, flags);
1469 		msleep(PCH_SLEEP_TIME);
1470 		spin_lock_irqsave(&data->lock, flags);
1471 	}
1472 	spin_unlock_irqrestore(&data->lock, flags);
1473 
1474 	pch_spi_free_resources(board_dat, data);
1475 	/* disable interrupts & free IRQ */
1476 	if (data->irq_reg_sts) {
1477 		/* disable interrupts */
1478 		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
1479 		data->irq_reg_sts = false;
1480 		free_irq(board_dat->pdev->irq, data);
1481 	}
1482 
1483 	pci_iounmap(board_dat->pdev, data->io_remap_addr);
1484 	spi_unregister_master(data->master);
1485 	spi_master_put(data->master);
1486 	platform_set_drvdata(plat_dev, NULL);
1487 
1488 	return 0;
1489 }
1490 #ifdef CONFIG_PM
1491 static int pch_spi_pd_suspend(struct platform_device *pd_dev,
1492 			      pm_message_t state)
1493 {
1494 	u8 count;
1495 	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
1496 	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
1497 
1498 	dev_dbg(&pd_dev->dev, "%s ENTRY\n", __func__);
1499 
1500 	if (!board_dat) {
1501 		dev_err(&pd_dev->dev,
1502 			"%s pci_get_drvdata returned NULL\n", __func__);
1503 		return -EFAULT;
1504 	}
1505 
1506 	/* check if the current message is processed:
1507 	   Only after thats done the transfer will be suspended */
1508 	count = 255;
1509 	while ((--count) > 0) {
1510 		if (!(data->bcurrent_msg_processing))
1511 			break;
1512 		msleep(PCH_SLEEP_TIME);
1513 	}
1514 
1515 	/* Free IRQ */
1516 	if (data->irq_reg_sts) {
1517 		/* disable all interrupts */
1518 		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
1519 		pch_spi_reset(data->master);
1520 		free_irq(board_dat->pdev->irq, data);
1521 
1522 		data->irq_reg_sts = false;
1523 		dev_dbg(&pd_dev->dev,
1524 			"%s free_irq invoked successfully.\n", __func__);
1525 	}
1526 
1527 	return 0;
1528 }
1529 
1530 static int pch_spi_pd_resume(struct platform_device *pd_dev)
1531 {
1532 	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
1533 	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
1534 	int retval;
1535 
1536 	if (!board_dat) {
1537 		dev_err(&pd_dev->dev,
1538 			"%s pci_get_drvdata returned NULL\n", __func__);
1539 		return -EFAULT;
1540 	}
1541 
1542 	if (!data->irq_reg_sts) {
1543 		/* register IRQ */
1544 		retval = request_irq(board_dat->pdev->irq, pch_spi_handler,
1545 				     IRQF_SHARED, KBUILD_MODNAME, data);
1546 		if (retval < 0) {
1547 			dev_err(&pd_dev->dev,
1548 				"%s request_irq failed\n", __func__);
1549 			return retval;
1550 		}
1551 
1552 		/* reset PCH SPI h/w */
1553 		pch_spi_reset(data->master);
1554 		pch_spi_set_master_mode(data->master);
1555 		data->irq_reg_sts = true;
1556 	}
1557 	return 0;
1558 }
1559 #else
1560 #define pch_spi_pd_suspend NULL
1561 #define pch_spi_pd_resume NULL
1562 #endif
1563 
1564 static struct platform_driver pch_spi_pd_driver = {
1565 	.driver = {
1566 		.name = "pch-spi",
1567 		.owner = THIS_MODULE,
1568 	},
1569 	.probe = pch_spi_pd_probe,
1570 	.remove = __devexit_p(pch_spi_pd_remove),
1571 	.suspend = pch_spi_pd_suspend,
1572 	.resume = pch_spi_pd_resume
1573 };
1574 
1575 static int __devinit pch_spi_probe(struct pci_dev *pdev,
1576 				   const struct pci_device_id *id)
1577 {
1578 	struct pch_spi_board_data *board_dat;
1579 	struct platform_device *pd_dev = NULL;
1580 	int retval;
1581 	int i;
1582 	struct pch_pd_dev_save *pd_dev_save;
1583 
1584 	pd_dev_save = kzalloc(sizeof(struct pch_pd_dev_save), GFP_KERNEL);
1585 	if (!pd_dev_save) {
1586 		dev_err(&pdev->dev, "%s Can't allocate pd_dev_sav\n", __func__);
1587 		return -ENOMEM;
1588 	}
1589 
1590 	board_dat = kzalloc(sizeof(struct pch_spi_board_data), GFP_KERNEL);
1591 	if (!board_dat) {
1592 		dev_err(&pdev->dev, "%s Can't allocate board_dat\n", __func__);
1593 		retval = -ENOMEM;
1594 		goto err_no_mem;
1595 	}
1596 
1597 	retval = pci_request_regions(pdev, KBUILD_MODNAME);
1598 	if (retval) {
1599 		dev_err(&pdev->dev, "%s request_region failed\n", __func__);
1600 		goto pci_request_regions;
1601 	}
1602 
1603 	board_dat->pdev = pdev;
1604 	board_dat->num = id->driver_data;
1605 	pd_dev_save->num = id->driver_data;
1606 	pd_dev_save->board_dat = board_dat;
1607 
1608 	retval = pci_enable_device(pdev);
1609 	if (retval) {
1610 		dev_err(&pdev->dev, "%s pci_enable_device failed\n", __func__);
1611 		goto pci_enable_device;
1612 	}
1613 
1614 	for (i = 0; i < board_dat->num; i++) {
1615 		pd_dev = platform_device_alloc("pch-spi", i);
1616 		if (!pd_dev) {
1617 			dev_err(&pdev->dev, "platform_device_alloc failed\n");
1618 			goto err_platform_device;
1619 		}
1620 		pd_dev_save->pd_save[i] = pd_dev;
1621 		pd_dev->dev.parent = &pdev->dev;
1622 
1623 		retval = platform_device_add_data(pd_dev, board_dat,
1624 						  sizeof(*board_dat));
1625 		if (retval) {
1626 			dev_err(&pdev->dev,
1627 				"platform_device_add_data failed\n");
1628 			platform_device_put(pd_dev);
1629 			goto err_platform_device;
1630 		}
1631 
1632 		retval = platform_device_add(pd_dev);
1633 		if (retval) {
1634 			dev_err(&pdev->dev, "platform_device_add failed\n");
1635 			platform_device_put(pd_dev);
1636 			goto err_platform_device;
1637 		}
1638 	}
1639 
1640 	pci_set_drvdata(pdev, pd_dev_save);
1641 
1642 	return 0;
1643 
1644 err_platform_device:
1645 	pci_disable_device(pdev);
1646 pci_enable_device:
1647 	pci_release_regions(pdev);
1648 pci_request_regions:
1649 	kfree(board_dat);
1650 err_no_mem:
1651 	kfree(pd_dev_save);
1652 
1653 	return retval;
1654 }
1655 
1656 static void __devexit pch_spi_remove(struct pci_dev *pdev)
1657 {
1658 	int i;
1659 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1660 
1661 	dev_dbg(&pdev->dev, "%s ENTRY:pdev=%p\n", __func__, pdev);
1662 
1663 	for (i = 0; i < pd_dev_save->num; i++)
1664 		platform_device_unregister(pd_dev_save->pd_save[i]);
1665 
1666 	pci_disable_device(pdev);
1667 	pci_release_regions(pdev);
1668 	kfree(pd_dev_save->board_dat);
1669 	kfree(pd_dev_save);
1670 }
1671 
1672 #ifdef CONFIG_PM
1673 static int pch_spi_suspend(struct pci_dev *pdev, pm_message_t state)
1674 {
1675 	int retval;
1676 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1677 
1678 	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
1679 
1680 	pd_dev_save->board_dat->suspend_sts = true;
1681 
1682 	/* save config space */
1683 	retval = pci_save_state(pdev);
1684 	if (retval == 0) {
1685 		pci_enable_wake(pdev, PCI_D3hot, 0);
1686 		pci_disable_device(pdev);
1687 		pci_set_power_state(pdev, PCI_D3hot);
1688 	} else {
1689 		dev_err(&pdev->dev, "%s pci_save_state failed\n", __func__);
1690 	}
1691 
1692 	return retval;
1693 }
1694 
1695 static int pch_spi_resume(struct pci_dev *pdev)
1696 {
1697 	int retval;
1698 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1699 	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
1700 
1701 	pci_set_power_state(pdev, PCI_D0);
1702 	pci_restore_state(pdev);
1703 
1704 	retval = pci_enable_device(pdev);
1705 	if (retval < 0) {
1706 		dev_err(&pdev->dev,
1707 			"%s pci_enable_device failed\n", __func__);
1708 	} else {
1709 		pci_enable_wake(pdev, PCI_D3hot, 0);
1710 
1711 		/* set suspend status to false */
1712 		pd_dev_save->board_dat->suspend_sts = false;
1713 	}
1714 
1715 	return retval;
1716 }
1717 #else
1718 #define pch_spi_suspend NULL
1719 #define pch_spi_resume NULL
1720 
1721 #endif
1722 
1723 static struct pci_driver pch_spi_pcidev = {
1724 	.name = "pch_spi",
1725 	.id_table = pch_spi_pcidev_id,
1726 	.probe = pch_spi_probe,
1727 	.remove = pch_spi_remove,
1728 	.suspend = pch_spi_suspend,
1729 	.resume = pch_spi_resume,
1730 };
1731 
1732 static int __init pch_spi_init(void)
1733 {
1734 	int ret;
1735 	ret = platform_driver_register(&pch_spi_pd_driver);
1736 	if (ret)
1737 		return ret;
1738 
1739 	ret = pci_register_driver(&pch_spi_pcidev);
1740 	if (ret)
1741 		return ret;
1742 
1743 	return 0;
1744 }
1745 module_init(pch_spi_init);
1746 
1747 static void __exit pch_spi_exit(void)
1748 {
1749 	pci_unregister_driver(&pch_spi_pcidev);
1750 	platform_driver_unregister(&pch_spi_pd_driver);
1751 }
1752 module_exit(pch_spi_exit);
1753 
1754 module_param(use_dma, int, 0644);
1755 MODULE_PARM_DESC(use_dma,
1756 		 "to use DMA for data transfers pass 1 else 0; default 1");
1757 
1758 MODULE_LICENSE("GPL");
1759 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semiconductor ML7xxx IOH SPI Driver");
1760