1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SPI bus driver for the Topcliff PCH used by Intel SoCs
4  *
5  * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/pci.h>
10 #include <linux/wait.h>
11 #include <linux/spi/spi.h>
12 #include <linux/interrupt.h>
13 #include <linux/sched.h>
14 #include <linux/spi/spidev.h>
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/platform_device.h>
18 
19 #include <linux/dmaengine.h>
20 #include <linux/pch_dma.h>
21 
22 /* Register offsets */
23 #define PCH_SPCR		0x00	/* SPI control register */
24 #define PCH_SPBRR		0x04	/* SPI baud rate register */
25 #define PCH_SPSR		0x08	/* SPI status register */
26 #define PCH_SPDWR		0x0C	/* SPI write data register */
27 #define PCH_SPDRR		0x10	/* SPI read data register */
28 #define PCH_SSNXCR		0x18	/* SSN Expand Control Register */
29 #define PCH_SRST		0x1C	/* SPI reset register */
30 #define PCH_ADDRESS_SIZE	0x20
31 
32 #define PCH_SPSR_TFD		0x000007C0
33 #define PCH_SPSR_RFD		0x0000F800
34 
35 #define PCH_READABLE(x)		(((x) & PCH_SPSR_RFD)>>11)
36 #define PCH_WRITABLE(x)		(((x) & PCH_SPSR_TFD)>>6)
37 
38 #define PCH_RX_THOLD		7
39 #define PCH_RX_THOLD_MAX	15
40 
41 #define PCH_TX_THOLD		2
42 
43 #define PCH_MAX_BAUDRATE	5000000
44 #define PCH_MAX_FIFO_DEPTH	16
45 
46 #define STATUS_RUNNING		1
47 #define STATUS_EXITING		2
48 #define PCH_SLEEP_TIME		10
49 
50 #define SSN_LOW			0x02U
51 #define SSN_HIGH		0x03U
52 #define SSN_NO_CONTROL		0x00U
53 #define PCH_MAX_CS		0xFF
54 #define PCI_DEVICE_ID_GE_SPI	0x8816
55 
56 #define SPCR_SPE_BIT		(1 << 0)
57 #define SPCR_MSTR_BIT		(1 << 1)
58 #define SPCR_LSBF_BIT		(1 << 4)
59 #define SPCR_CPHA_BIT		(1 << 5)
60 #define SPCR_CPOL_BIT		(1 << 6)
61 #define SPCR_TFIE_BIT		(1 << 8)
62 #define SPCR_RFIE_BIT		(1 << 9)
63 #define SPCR_FIE_BIT		(1 << 10)
64 #define SPCR_ORIE_BIT		(1 << 11)
65 #define SPCR_MDFIE_BIT		(1 << 12)
66 #define SPCR_FICLR_BIT		(1 << 24)
67 #define SPSR_TFI_BIT		(1 << 0)
68 #define SPSR_RFI_BIT		(1 << 1)
69 #define SPSR_FI_BIT		(1 << 2)
70 #define SPSR_ORF_BIT		(1 << 3)
71 #define SPBRR_SIZE_BIT		(1 << 10)
72 
73 #define PCH_ALL			(SPCR_TFIE_BIT|SPCR_RFIE_BIT|SPCR_FIE_BIT|\
74 				SPCR_ORIE_BIT|SPCR_MDFIE_BIT)
75 
76 #define SPCR_RFIC_FIELD		20
77 #define SPCR_TFIC_FIELD		16
78 
79 #define MASK_SPBRR_SPBR_BITS	((1 << 10) - 1)
80 #define MASK_RFIC_SPCR_BITS	(0xf << SPCR_RFIC_FIELD)
81 #define MASK_TFIC_SPCR_BITS	(0xf << SPCR_TFIC_FIELD)
82 
83 #define PCH_CLOCK_HZ		50000000
84 #define PCH_MAX_SPBR		1023
85 
86 /* Definition for ML7213/ML7223/ML7831 by LAPIS Semiconductor */
87 #define PCI_DEVICE_ID_ML7213_SPI	0x802c
88 #define PCI_DEVICE_ID_ML7223_SPI	0x800F
89 #define PCI_DEVICE_ID_ML7831_SPI	0x8816
90 
91 /*
92  * Set the number of SPI instance max
93  * Intel EG20T PCH :		1ch
94  * LAPIS Semiconductor ML7213 IOH :	2ch
95  * LAPIS Semiconductor ML7223 IOH :	1ch
96  * LAPIS Semiconductor ML7831 IOH :	1ch
97 */
98 #define PCH_SPI_MAX_DEV			2
99 
100 #define PCH_BUF_SIZE		4096
101 #define PCH_DMA_TRANS_SIZE	12
102 
103 static int use_dma = 1;
104 
105 struct pch_spi_dma_ctrl {
106 	struct pci_dev		*dma_dev;
107 	struct dma_async_tx_descriptor	*desc_tx;
108 	struct dma_async_tx_descriptor	*desc_rx;
109 	struct pch_dma_slave		param_tx;
110 	struct pch_dma_slave		param_rx;
111 	struct dma_chan		*chan_tx;
112 	struct dma_chan		*chan_rx;
113 	struct scatterlist		*sg_tx_p;
114 	struct scatterlist		*sg_rx_p;
115 	struct scatterlist		sg_tx;
116 	struct scatterlist		sg_rx;
117 	int				nent;
118 	void				*tx_buf_virt;
119 	void				*rx_buf_virt;
120 	dma_addr_t			tx_buf_dma;
121 	dma_addr_t			rx_buf_dma;
122 };
123 /**
124  * struct pch_spi_data - Holds the SPI channel specific details
125  * @io_remap_addr:		The remapped PCI base address
126  * @io_base_addr:		Base address
127  * @master:			Pointer to the SPI master structure
128  * @work:			Reference to work queue handler
129  * @wait:			Wait queue for waking up upon receiving an
130  *				interrupt.
131  * @transfer_complete:		Status of SPI Transfer
132  * @bcurrent_msg_processing:	Status flag for message processing
133  * @lock:			Lock for protecting this structure
134  * @queue:			SPI Message queue
135  * @status:			Status of the SPI driver
136  * @bpw_len:			Length of data to be transferred in bits per
137  *				word
138  * @transfer_active:		Flag showing active transfer
139  * @tx_index:			Transmit data count; for bookkeeping during
140  *				transfer
141  * @rx_index:			Receive data count; for bookkeeping during
142  *				transfer
143  * @pkt_tx_buff:		Buffer for data to be transmitted
144  * @pkt_rx_buff:		Buffer for received data
145  * @n_curnt_chip:		The chip number that this SPI driver currently
146  *				operates on
147  * @current_chip:		Reference to the current chip that this SPI
148  *				driver currently operates on
149  * @current_msg:		The current message that this SPI driver is
150  *				handling
151  * @cur_trans:			The current transfer that this SPI driver is
152  *				handling
153  * @board_dat:			Reference to the SPI device data structure
154  * @plat_dev:			platform_device structure
155  * @ch:				SPI channel number
156  * @dma:			Local DMA information
157  * @use_dma:			True if DMA is to be used
158  * @irq_reg_sts:		Status of IRQ registration
159  * @save_total_len:		Save length while data is being transferred
160  */
161 struct pch_spi_data {
162 	void __iomem *io_remap_addr;
163 	unsigned long io_base_addr;
164 	struct spi_master *master;
165 	struct work_struct work;
166 	wait_queue_head_t wait;
167 	u8 transfer_complete;
168 	u8 bcurrent_msg_processing;
169 	spinlock_t lock;
170 	struct list_head queue;
171 	u8 status;
172 	u32 bpw_len;
173 	u8 transfer_active;
174 	u32 tx_index;
175 	u32 rx_index;
176 	u16 *pkt_tx_buff;
177 	u16 *pkt_rx_buff;
178 	u8 n_curnt_chip;
179 	struct spi_device *current_chip;
180 	struct spi_message *current_msg;
181 	struct spi_transfer *cur_trans;
182 	struct pch_spi_board_data *board_dat;
183 	struct platform_device	*plat_dev;
184 	int ch;
185 	struct pch_spi_dma_ctrl dma;
186 	int use_dma;
187 	u8 irq_reg_sts;
188 	int save_total_len;
189 };
190 
191 /**
192  * struct pch_spi_board_data - Holds the SPI device specific details
193  * @pdev:		Pointer to the PCI device
194  * @suspend_sts:	Status of suspend
195  * @num:		The number of SPI device instance
196  */
197 struct pch_spi_board_data {
198 	struct pci_dev *pdev;
199 	u8 suspend_sts;
200 	int num;
201 };
202 
203 struct pch_pd_dev_save {
204 	int num;
205 	struct platform_device *pd_save[PCH_SPI_MAX_DEV];
206 	struct pch_spi_board_data *board_dat;
207 };
208 
209 static const struct pci_device_id pch_spi_pcidev_id[] = {
210 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_GE_SPI),    1, },
211 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_SPI), 2, },
212 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_SPI), 1, },
213 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_SPI), 1, },
214 	{ }
215 };
216 
217 /**
218  * pch_spi_writereg() - Performs  register writes
219  * @master:	Pointer to struct spi_master.
220  * @idx:	Register offset.
221  * @val:	Value to be written to register.
222  */
223 static inline void pch_spi_writereg(struct spi_master *master, int idx, u32 val)
224 {
225 	struct pch_spi_data *data = spi_master_get_devdata(master);
226 	iowrite32(val, (data->io_remap_addr + idx));
227 }
228 
229 /**
230  * pch_spi_readreg() - Performs register reads
231  * @master:	Pointer to struct spi_master.
232  * @idx:	Register offset.
233  */
234 static inline u32 pch_spi_readreg(struct spi_master *master, int idx)
235 {
236 	struct pch_spi_data *data = spi_master_get_devdata(master);
237 	return ioread32(data->io_remap_addr + idx);
238 }
239 
240 static inline void pch_spi_setclr_reg(struct spi_master *master, int idx,
241 				      u32 set, u32 clr)
242 {
243 	u32 tmp = pch_spi_readreg(master, idx);
244 	tmp = (tmp & ~clr) | set;
245 	pch_spi_writereg(master, idx, tmp);
246 }
247 
248 static void pch_spi_set_master_mode(struct spi_master *master)
249 {
250 	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_MSTR_BIT, 0);
251 }
252 
253 /**
254  * pch_spi_clear_fifo() - Clears the Transmit and Receive FIFOs
255  * @master:	Pointer to struct spi_master.
256  */
257 static void pch_spi_clear_fifo(struct spi_master *master)
258 {
259 	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_FICLR_BIT, 0);
260 	pch_spi_setclr_reg(master, PCH_SPCR, 0, SPCR_FICLR_BIT);
261 }
262 
263 static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
264 				void __iomem *io_remap_addr)
265 {
266 	u32 n_read, tx_index, rx_index, bpw_len;
267 	u16 *pkt_rx_buffer, *pkt_tx_buff;
268 	int read_cnt;
269 	u32 reg_spcr_val;
270 	void __iomem *spsr;
271 	void __iomem *spdrr;
272 	void __iomem *spdwr;
273 
274 	spsr = io_remap_addr + PCH_SPSR;
275 	iowrite32(reg_spsr_val, spsr);
276 
277 	if (data->transfer_active) {
278 		rx_index = data->rx_index;
279 		tx_index = data->tx_index;
280 		bpw_len = data->bpw_len;
281 		pkt_rx_buffer = data->pkt_rx_buff;
282 		pkt_tx_buff = data->pkt_tx_buff;
283 
284 		spdrr = io_remap_addr + PCH_SPDRR;
285 		spdwr = io_remap_addr + PCH_SPDWR;
286 
287 		n_read = PCH_READABLE(reg_spsr_val);
288 
289 		for (read_cnt = 0; (read_cnt < n_read); read_cnt++) {
290 			pkt_rx_buffer[rx_index++] = ioread32(spdrr);
291 			if (tx_index < bpw_len)
292 				iowrite32(pkt_tx_buff[tx_index++], spdwr);
293 		}
294 
295 		/* disable RFI if not needed */
296 		if ((bpw_len - rx_index) <= PCH_MAX_FIFO_DEPTH) {
297 			reg_spcr_val = ioread32(io_remap_addr + PCH_SPCR);
298 			reg_spcr_val &= ~SPCR_RFIE_BIT; /* disable RFI */
299 
300 			/* reset rx threshold */
301 			reg_spcr_val &= ~MASK_RFIC_SPCR_BITS;
302 			reg_spcr_val |= (PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD);
303 
304 			iowrite32(reg_spcr_val, (io_remap_addr + PCH_SPCR));
305 		}
306 
307 		/* update counts */
308 		data->tx_index = tx_index;
309 		data->rx_index = rx_index;
310 
311 		/* if transfer complete interrupt */
312 		if (reg_spsr_val & SPSR_FI_BIT) {
313 			if ((tx_index == bpw_len) && (rx_index == tx_index)) {
314 				/* disable interrupts */
315 				pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
316 						   PCH_ALL);
317 
318 				/* transfer is completed;
319 				   inform pch_spi_process_messages */
320 				data->transfer_complete = true;
321 				data->transfer_active = false;
322 				wake_up(&data->wait);
323 			} else {
324 				dev_vdbg(&data->master->dev,
325 					"%s : Transfer is not completed",
326 					__func__);
327 			}
328 		}
329 	}
330 }
331 
332 /**
333  * pch_spi_handler() - Interrupt handler
334  * @irq:	The interrupt number.
335  * @dev_id:	Pointer to struct pch_spi_board_data.
336  */
337 static irqreturn_t pch_spi_handler(int irq, void *dev_id)
338 {
339 	u32 reg_spsr_val;
340 	void __iomem *spsr;
341 	void __iomem *io_remap_addr;
342 	irqreturn_t ret = IRQ_NONE;
343 	struct pch_spi_data *data = dev_id;
344 	struct pch_spi_board_data *board_dat = data->board_dat;
345 
346 	if (board_dat->suspend_sts) {
347 		dev_dbg(&board_dat->pdev->dev,
348 			"%s returning due to suspend\n", __func__);
349 		return IRQ_NONE;
350 	}
351 
352 	io_remap_addr = data->io_remap_addr;
353 	spsr = io_remap_addr + PCH_SPSR;
354 
355 	reg_spsr_val = ioread32(spsr);
356 
357 	if (reg_spsr_val & SPSR_ORF_BIT) {
358 		dev_err(&board_dat->pdev->dev, "%s Over run error\n", __func__);
359 		if (data->current_msg->complete) {
360 			data->transfer_complete = true;
361 			data->current_msg->status = -EIO;
362 			data->current_msg->complete(data->current_msg->context);
363 			data->bcurrent_msg_processing = false;
364 			data->current_msg = NULL;
365 			data->cur_trans = NULL;
366 		}
367 	}
368 
369 	if (data->use_dma)
370 		return IRQ_NONE;
371 
372 	/* Check if the interrupt is for SPI device */
373 	if (reg_spsr_val & (SPSR_FI_BIT | SPSR_RFI_BIT)) {
374 		pch_spi_handler_sub(data, reg_spsr_val, io_remap_addr);
375 		ret = IRQ_HANDLED;
376 	}
377 
378 	dev_dbg(&board_dat->pdev->dev, "%s EXIT return value=%d\n",
379 		__func__, ret);
380 
381 	return ret;
382 }
383 
384 /**
385  * pch_spi_set_baud_rate() - Sets SPBR field in SPBRR
386  * @master:	Pointer to struct spi_master.
387  * @speed_hz:	Baud rate.
388  */
389 static void pch_spi_set_baud_rate(struct spi_master *master, u32 speed_hz)
390 {
391 	u32 n_spbr = PCH_CLOCK_HZ / (speed_hz * 2);
392 
393 	/* if baud rate is less than we can support limit it */
394 	if (n_spbr > PCH_MAX_SPBR)
395 		n_spbr = PCH_MAX_SPBR;
396 
397 	pch_spi_setclr_reg(master, PCH_SPBRR, n_spbr, MASK_SPBRR_SPBR_BITS);
398 }
399 
400 /**
401  * pch_spi_set_bits_per_word() - Sets SIZE field in SPBRR
402  * @master:		Pointer to struct spi_master.
403  * @bits_per_word:	Bits per word for SPI transfer.
404  */
405 static void pch_spi_set_bits_per_word(struct spi_master *master,
406 				      u8 bits_per_word)
407 {
408 	if (bits_per_word == 8)
409 		pch_spi_setclr_reg(master, PCH_SPBRR, 0, SPBRR_SIZE_BIT);
410 	else
411 		pch_spi_setclr_reg(master, PCH_SPBRR, SPBRR_SIZE_BIT, 0);
412 }
413 
414 /**
415  * pch_spi_setup_transfer() - Configures the PCH SPI hardware for transfer
416  * @spi:	Pointer to struct spi_device.
417  */
418 static void pch_spi_setup_transfer(struct spi_device *spi)
419 {
420 	u32 flags = 0;
421 
422 	dev_dbg(&spi->dev, "%s SPBRR content =%x setting baud rate=%d\n",
423 		__func__, pch_spi_readreg(spi->master, PCH_SPBRR),
424 		spi->max_speed_hz);
425 	pch_spi_set_baud_rate(spi->master, spi->max_speed_hz);
426 
427 	/* set bits per word */
428 	pch_spi_set_bits_per_word(spi->master, spi->bits_per_word);
429 
430 	if (!(spi->mode & SPI_LSB_FIRST))
431 		flags |= SPCR_LSBF_BIT;
432 	if (spi->mode & SPI_CPOL)
433 		flags |= SPCR_CPOL_BIT;
434 	if (spi->mode & SPI_CPHA)
435 		flags |= SPCR_CPHA_BIT;
436 	pch_spi_setclr_reg(spi->master, PCH_SPCR, flags,
437 			   (SPCR_LSBF_BIT | SPCR_CPOL_BIT | SPCR_CPHA_BIT));
438 
439 	/* Clear the FIFO by toggling  FICLR to 1 and back to 0 */
440 	pch_spi_clear_fifo(spi->master);
441 }
442 
443 /**
444  * pch_spi_reset() - Clears SPI registers
445  * @master:	Pointer to struct spi_master.
446  */
447 static void pch_spi_reset(struct spi_master *master)
448 {
449 	/* write 1 to reset SPI */
450 	pch_spi_writereg(master, PCH_SRST, 0x1);
451 
452 	/* clear reset */
453 	pch_spi_writereg(master, PCH_SRST, 0x0);
454 }
455 
456 static int pch_spi_transfer(struct spi_device *pspi, struct spi_message *pmsg)
457 {
458 
459 	struct spi_transfer *transfer;
460 	struct pch_spi_data *data = spi_master_get_devdata(pspi->master);
461 	int retval;
462 	unsigned long flags;
463 
464 	spin_lock_irqsave(&data->lock, flags);
465 	/* validate Tx/Rx buffers and Transfer length */
466 	list_for_each_entry(transfer, &pmsg->transfers, transfer_list) {
467 		if (!transfer->tx_buf && !transfer->rx_buf) {
468 			dev_err(&pspi->dev,
469 				"%s Tx and Rx buffer NULL\n", __func__);
470 			retval = -EINVAL;
471 			goto err_return_spinlock;
472 		}
473 
474 		if (!transfer->len) {
475 			dev_err(&pspi->dev, "%s Transfer length invalid\n",
476 				__func__);
477 			retval = -EINVAL;
478 			goto err_return_spinlock;
479 		}
480 
481 		dev_dbg(&pspi->dev,
482 			"%s Tx/Rx buffer valid. Transfer length valid\n",
483 			__func__);
484 	}
485 	spin_unlock_irqrestore(&data->lock, flags);
486 
487 	/* We won't process any messages if we have been asked to terminate */
488 	if (data->status == STATUS_EXITING) {
489 		dev_err(&pspi->dev, "%s status = STATUS_EXITING.\n", __func__);
490 		retval = -ESHUTDOWN;
491 		goto err_out;
492 	}
493 
494 	/* If suspended ,return -EINVAL */
495 	if (data->board_dat->suspend_sts) {
496 		dev_err(&pspi->dev, "%s suspend; returning EINVAL\n", __func__);
497 		retval = -EINVAL;
498 		goto err_out;
499 	}
500 
501 	/* set status of message */
502 	pmsg->actual_length = 0;
503 	dev_dbg(&pspi->dev, "%s - pmsg->status =%d\n", __func__, pmsg->status);
504 
505 	pmsg->status = -EINPROGRESS;
506 	spin_lock_irqsave(&data->lock, flags);
507 	/* add message to queue */
508 	list_add_tail(&pmsg->queue, &data->queue);
509 	spin_unlock_irqrestore(&data->lock, flags);
510 
511 	dev_dbg(&pspi->dev, "%s - Invoked list_add_tail\n", __func__);
512 
513 	schedule_work(&data->work);
514 	dev_dbg(&pspi->dev, "%s - Invoked queue work\n", __func__);
515 
516 	retval = 0;
517 
518 err_out:
519 	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
520 	return retval;
521 err_return_spinlock:
522 	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
523 	spin_unlock_irqrestore(&data->lock, flags);
524 	return retval;
525 }
526 
527 static inline void pch_spi_select_chip(struct pch_spi_data *data,
528 				       struct spi_device *pspi)
529 {
530 	if (data->current_chip != NULL) {
531 		if (pspi->chip_select != data->n_curnt_chip) {
532 			dev_dbg(&pspi->dev, "%s : different slave\n", __func__);
533 			data->current_chip = NULL;
534 		}
535 	}
536 
537 	data->current_chip = pspi;
538 
539 	data->n_curnt_chip = data->current_chip->chip_select;
540 
541 	dev_dbg(&pspi->dev, "%s :Invoking pch_spi_setup_transfer\n", __func__);
542 	pch_spi_setup_transfer(pspi);
543 }
544 
545 static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)
546 {
547 	int size;
548 	u32 n_writes;
549 	int j;
550 	struct spi_message *pmsg, *tmp;
551 	const u8 *tx_buf;
552 	const u16 *tx_sbuf;
553 
554 	/* set baud rate if needed */
555 	if (data->cur_trans->speed_hz) {
556 		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
557 		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
558 	}
559 
560 	/* set bits per word if needed */
561 	if (data->cur_trans->bits_per_word &&
562 	    (data->current_msg->spi->bits_per_word != data->cur_trans->bits_per_word)) {
563 		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
564 		pch_spi_set_bits_per_word(data->master,
565 					  data->cur_trans->bits_per_word);
566 		*bpw = data->cur_trans->bits_per_word;
567 	} else {
568 		*bpw = data->current_msg->spi->bits_per_word;
569 	}
570 
571 	/* reset Tx/Rx index */
572 	data->tx_index = 0;
573 	data->rx_index = 0;
574 
575 	data->bpw_len = data->cur_trans->len / (*bpw / 8);
576 
577 	/* find alloc size */
578 	size = data->cur_trans->len * sizeof(*data->pkt_tx_buff);
579 
580 	/* allocate memory for pkt_tx_buff & pkt_rx_buffer */
581 	data->pkt_tx_buff = kzalloc(size, GFP_KERNEL);
582 	if (data->pkt_tx_buff != NULL) {
583 		data->pkt_rx_buff = kzalloc(size, GFP_KERNEL);
584 		if (!data->pkt_rx_buff) {
585 			kfree(data->pkt_tx_buff);
586 			data->pkt_tx_buff = NULL;
587 		}
588 	}
589 
590 	if (!data->pkt_rx_buff) {
591 		/* flush queue and set status of all transfers to -ENOMEM */
592 		list_for_each_entry_safe(pmsg, tmp, data->queue.next, queue) {
593 			pmsg->status = -ENOMEM;
594 
595 			if (pmsg->complete)
596 				pmsg->complete(pmsg->context);
597 
598 			/* delete from queue */
599 			list_del_init(&pmsg->queue);
600 		}
601 		return;
602 	}
603 
604 	/* copy Tx Data */
605 	if (data->cur_trans->tx_buf != NULL) {
606 		if (*bpw == 8) {
607 			tx_buf = data->cur_trans->tx_buf;
608 			for (j = 0; j < data->bpw_len; j++)
609 				data->pkt_tx_buff[j] = *tx_buf++;
610 		} else {
611 			tx_sbuf = data->cur_trans->tx_buf;
612 			for (j = 0; j < data->bpw_len; j++)
613 				data->pkt_tx_buff[j] = *tx_sbuf++;
614 		}
615 	}
616 
617 	/* if len greater than PCH_MAX_FIFO_DEPTH, write 16,else len bytes */
618 	n_writes = data->bpw_len;
619 	if (n_writes > PCH_MAX_FIFO_DEPTH)
620 		n_writes = PCH_MAX_FIFO_DEPTH;
621 
622 	dev_dbg(&data->master->dev,
623 		"\n%s:Pulling down SSN low - writing 0x2 to SSNXCR\n",
624 		__func__);
625 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
626 
627 	for (j = 0; j < n_writes; j++)
628 		pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
629 
630 	/* update tx_index */
631 	data->tx_index = j;
632 
633 	/* reset transfer complete flag */
634 	data->transfer_complete = false;
635 	data->transfer_active = true;
636 }
637 
638 static void pch_spi_nomore_transfer(struct pch_spi_data *data)
639 {
640 	struct spi_message *pmsg, *tmp;
641 	dev_dbg(&data->master->dev, "%s called\n", __func__);
642 	/* Invoke complete callback
643 	 * [To the spi core..indicating end of transfer] */
644 	data->current_msg->status = 0;
645 
646 	if (data->current_msg->complete) {
647 		dev_dbg(&data->master->dev,
648 			"%s:Invoking callback of SPI core\n", __func__);
649 		data->current_msg->complete(data->current_msg->context);
650 	}
651 
652 	/* update status in global variable */
653 	data->bcurrent_msg_processing = false;
654 
655 	dev_dbg(&data->master->dev,
656 		"%s:data->bcurrent_msg_processing = false\n", __func__);
657 
658 	data->current_msg = NULL;
659 	data->cur_trans = NULL;
660 
661 	/* check if we have items in list and not suspending
662 	 * return 1 if list empty */
663 	if ((list_empty(&data->queue) == 0) &&
664 	    (!data->board_dat->suspend_sts) &&
665 	    (data->status != STATUS_EXITING)) {
666 		/* We have some more work to do (either there is more tranint
667 		 * bpw;sfer requests in the current message or there are
668 		 *more messages)
669 		 */
670 		dev_dbg(&data->master->dev, "%s:Invoke queue_work\n", __func__);
671 		schedule_work(&data->work);
672 	} else if (data->board_dat->suspend_sts ||
673 		   data->status == STATUS_EXITING) {
674 		dev_dbg(&data->master->dev,
675 			"%s suspend/remove initiated, flushing queue\n",
676 			__func__);
677 		list_for_each_entry_safe(pmsg, tmp, data->queue.next, queue) {
678 			pmsg->status = -EIO;
679 
680 			if (pmsg->complete)
681 				pmsg->complete(pmsg->context);
682 
683 			/* delete from queue */
684 			list_del_init(&pmsg->queue);
685 		}
686 	}
687 }
688 
689 static void pch_spi_set_ir(struct pch_spi_data *data)
690 {
691 	/* enable interrupts, set threshold, enable SPI */
692 	if ((data->bpw_len) > PCH_MAX_FIFO_DEPTH)
693 		/* set receive threshold to PCH_RX_THOLD */
694 		pch_spi_setclr_reg(data->master, PCH_SPCR,
695 				   PCH_RX_THOLD << SPCR_RFIC_FIELD |
696 				   SPCR_FIE_BIT | SPCR_RFIE_BIT |
697 				   SPCR_ORIE_BIT | SPCR_SPE_BIT,
698 				   MASK_RFIC_SPCR_BITS | PCH_ALL);
699 	else
700 		/* set receive threshold to maximum */
701 		pch_spi_setclr_reg(data->master, PCH_SPCR,
702 				   PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD |
703 				   SPCR_FIE_BIT | SPCR_ORIE_BIT |
704 				   SPCR_SPE_BIT,
705 				   MASK_RFIC_SPCR_BITS | PCH_ALL);
706 
707 	/* Wait until the transfer completes; go to sleep after
708 				 initiating the transfer. */
709 	dev_dbg(&data->master->dev,
710 		"%s:waiting for transfer to get over\n", __func__);
711 
712 	wait_event_interruptible(data->wait, data->transfer_complete);
713 
714 	/* clear all interrupts */
715 	pch_spi_writereg(data->master, PCH_SPSR,
716 			 pch_spi_readreg(data->master, PCH_SPSR));
717 	/* Disable interrupts and SPI transfer */
718 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL | SPCR_SPE_BIT);
719 	/* clear FIFO */
720 	pch_spi_clear_fifo(data->master);
721 }
722 
723 static void pch_spi_copy_rx_data(struct pch_spi_data *data, int bpw)
724 {
725 	int j;
726 	u8 *rx_buf;
727 	u16 *rx_sbuf;
728 
729 	/* copy Rx Data */
730 	if (!data->cur_trans->rx_buf)
731 		return;
732 
733 	if (bpw == 8) {
734 		rx_buf = data->cur_trans->rx_buf;
735 		for (j = 0; j < data->bpw_len; j++)
736 			*rx_buf++ = data->pkt_rx_buff[j] & 0xFF;
737 	} else {
738 		rx_sbuf = data->cur_trans->rx_buf;
739 		for (j = 0; j < data->bpw_len; j++)
740 			*rx_sbuf++ = data->pkt_rx_buff[j];
741 	}
742 }
743 
744 static void pch_spi_copy_rx_data_for_dma(struct pch_spi_data *data, int bpw)
745 {
746 	int j;
747 	u8 *rx_buf;
748 	u16 *rx_sbuf;
749 	const u8 *rx_dma_buf;
750 	const u16 *rx_dma_sbuf;
751 
752 	/* copy Rx Data */
753 	if (!data->cur_trans->rx_buf)
754 		return;
755 
756 	if (bpw == 8) {
757 		rx_buf = data->cur_trans->rx_buf;
758 		rx_dma_buf = data->dma.rx_buf_virt;
759 		for (j = 0; j < data->bpw_len; j++)
760 			*rx_buf++ = *rx_dma_buf++ & 0xFF;
761 		data->cur_trans->rx_buf = rx_buf;
762 	} else {
763 		rx_sbuf = data->cur_trans->rx_buf;
764 		rx_dma_sbuf = data->dma.rx_buf_virt;
765 		for (j = 0; j < data->bpw_len; j++)
766 			*rx_sbuf++ = *rx_dma_sbuf++;
767 		data->cur_trans->rx_buf = rx_sbuf;
768 	}
769 }
770 
771 static int pch_spi_start_transfer(struct pch_spi_data *data)
772 {
773 	struct pch_spi_dma_ctrl *dma;
774 	unsigned long flags;
775 	int rtn;
776 
777 	dma = &data->dma;
778 
779 	spin_lock_irqsave(&data->lock, flags);
780 
781 	/* disable interrupts, SPI set enable */
782 	pch_spi_setclr_reg(data->master, PCH_SPCR, SPCR_SPE_BIT, PCH_ALL);
783 
784 	spin_unlock_irqrestore(&data->lock, flags);
785 
786 	/* Wait until the transfer completes; go to sleep after
787 				 initiating the transfer. */
788 	dev_dbg(&data->master->dev,
789 		"%s:waiting for transfer to get over\n", __func__);
790 	rtn = wait_event_interruptible_timeout(data->wait,
791 					       data->transfer_complete,
792 					       msecs_to_jiffies(2 * HZ));
793 	if (!rtn)
794 		dev_err(&data->master->dev,
795 			"%s wait-event timeout\n", __func__);
796 
797 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
798 			    DMA_FROM_DEVICE);
799 
800 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_tx_p, dma->nent,
801 			    DMA_FROM_DEVICE);
802 	memset(data->dma.tx_buf_virt, 0, PAGE_SIZE);
803 
804 	async_tx_ack(dma->desc_rx);
805 	async_tx_ack(dma->desc_tx);
806 	kfree(dma->sg_tx_p);
807 	kfree(dma->sg_rx_p);
808 
809 	spin_lock_irqsave(&data->lock, flags);
810 
811 	/* clear fifo threshold, disable interrupts, disable SPI transfer */
812 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
813 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS | PCH_ALL |
814 			   SPCR_SPE_BIT);
815 	/* clear all interrupts */
816 	pch_spi_writereg(data->master, PCH_SPSR,
817 			 pch_spi_readreg(data->master, PCH_SPSR));
818 	/* clear FIFO */
819 	pch_spi_clear_fifo(data->master);
820 
821 	spin_unlock_irqrestore(&data->lock, flags);
822 
823 	return rtn;
824 }
825 
826 static void pch_dma_rx_complete(void *arg)
827 {
828 	struct pch_spi_data *data = arg;
829 
830 	/* transfer is completed;inform pch_spi_process_messages_dma */
831 	data->transfer_complete = true;
832 	wake_up_interruptible(&data->wait);
833 }
834 
835 static bool pch_spi_filter(struct dma_chan *chan, void *slave)
836 {
837 	struct pch_dma_slave *param = slave;
838 
839 	if ((chan->chan_id == param->chan_id) &&
840 	    (param->dma_dev == chan->device->dev)) {
841 		chan->private = param;
842 		return true;
843 	} else {
844 		return false;
845 	}
846 }
847 
848 static void pch_spi_request_dma(struct pch_spi_data *data, int bpw)
849 {
850 	dma_cap_mask_t mask;
851 	struct dma_chan *chan;
852 	struct pci_dev *dma_dev;
853 	struct pch_dma_slave *param;
854 	struct pch_spi_dma_ctrl *dma;
855 	unsigned int width;
856 
857 	if (bpw == 8)
858 		width = PCH_DMA_WIDTH_1_BYTE;
859 	else
860 		width = PCH_DMA_WIDTH_2_BYTES;
861 
862 	dma = &data->dma;
863 	dma_cap_zero(mask);
864 	dma_cap_set(DMA_SLAVE, mask);
865 
866 	/* Get DMA's dev information */
867 	dma_dev = pci_get_slot(data->board_dat->pdev->bus,
868 			PCI_DEVFN(PCI_SLOT(data->board_dat->pdev->devfn), 0));
869 
870 	/* Set Tx DMA */
871 	param = &dma->param_tx;
872 	param->dma_dev = &dma_dev->dev;
873 	param->chan_id = data->ch * 2; /* Tx = 0, 2 */
874 	param->tx_reg = data->io_base_addr + PCH_SPDWR;
875 	param->width = width;
876 	chan = dma_request_channel(mask, pch_spi_filter, param);
877 	if (!chan) {
878 		dev_err(&data->master->dev,
879 			"ERROR: dma_request_channel FAILS(Tx)\n");
880 		goto out;
881 	}
882 	dma->chan_tx = chan;
883 
884 	/* Set Rx DMA */
885 	param = &dma->param_rx;
886 	param->dma_dev = &dma_dev->dev;
887 	param->chan_id = data->ch * 2 + 1; /* Rx = Tx + 1 */
888 	param->rx_reg = data->io_base_addr + PCH_SPDRR;
889 	param->width = width;
890 	chan = dma_request_channel(mask, pch_spi_filter, param);
891 	if (!chan) {
892 		dev_err(&data->master->dev,
893 			"ERROR: dma_request_channel FAILS(Rx)\n");
894 		dma_release_channel(dma->chan_tx);
895 		dma->chan_tx = NULL;
896 		goto out;
897 	}
898 	dma->chan_rx = chan;
899 
900 	dma->dma_dev = dma_dev;
901 	return;
902 out:
903 	pci_dev_put(dma_dev);
904 	data->use_dma = 0;
905 }
906 
907 static void pch_spi_release_dma(struct pch_spi_data *data)
908 {
909 	struct pch_spi_dma_ctrl *dma;
910 
911 	dma = &data->dma;
912 	if (dma->chan_tx) {
913 		dma_release_channel(dma->chan_tx);
914 		dma->chan_tx = NULL;
915 	}
916 	if (dma->chan_rx) {
917 		dma_release_channel(dma->chan_rx);
918 		dma->chan_rx = NULL;
919 	}
920 
921 	pci_dev_put(dma->dma_dev);
922 }
923 
924 static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
925 {
926 	const u8 *tx_buf;
927 	const u16 *tx_sbuf;
928 	u8 *tx_dma_buf;
929 	u16 *tx_dma_sbuf;
930 	struct scatterlist *sg;
931 	struct dma_async_tx_descriptor *desc_tx;
932 	struct dma_async_tx_descriptor *desc_rx;
933 	int num;
934 	int i;
935 	int size;
936 	int rem;
937 	int head;
938 	unsigned long flags;
939 	struct pch_spi_dma_ctrl *dma;
940 
941 	dma = &data->dma;
942 
943 	/* set baud rate if needed */
944 	if (data->cur_trans->speed_hz) {
945 		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
946 		spin_lock_irqsave(&data->lock, flags);
947 		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
948 		spin_unlock_irqrestore(&data->lock, flags);
949 	}
950 
951 	/* set bits per word if needed */
952 	if (data->cur_trans->bits_per_word &&
953 	    (data->current_msg->spi->bits_per_word !=
954 	     data->cur_trans->bits_per_word)) {
955 		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
956 		spin_lock_irqsave(&data->lock, flags);
957 		pch_spi_set_bits_per_word(data->master,
958 					  data->cur_trans->bits_per_word);
959 		spin_unlock_irqrestore(&data->lock, flags);
960 		*bpw = data->cur_trans->bits_per_word;
961 	} else {
962 		*bpw = data->current_msg->spi->bits_per_word;
963 	}
964 	data->bpw_len = data->cur_trans->len / (*bpw / 8);
965 
966 	if (data->bpw_len > PCH_BUF_SIZE) {
967 		data->bpw_len = PCH_BUF_SIZE;
968 		data->cur_trans->len -= PCH_BUF_SIZE;
969 	}
970 
971 	/* copy Tx Data */
972 	if (data->cur_trans->tx_buf != NULL) {
973 		if (*bpw == 8) {
974 			tx_buf = data->cur_trans->tx_buf;
975 			tx_dma_buf = dma->tx_buf_virt;
976 			for (i = 0; i < data->bpw_len; i++)
977 				*tx_dma_buf++ = *tx_buf++;
978 		} else {
979 			tx_sbuf = data->cur_trans->tx_buf;
980 			tx_dma_sbuf = dma->tx_buf_virt;
981 			for (i = 0; i < data->bpw_len; i++)
982 				*tx_dma_sbuf++ = *tx_sbuf++;
983 		}
984 	}
985 
986 	/* Calculate Rx parameter for DMA transmitting */
987 	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
988 		if (data->bpw_len % PCH_DMA_TRANS_SIZE) {
989 			num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
990 			rem = data->bpw_len % PCH_DMA_TRANS_SIZE;
991 		} else {
992 			num = data->bpw_len / PCH_DMA_TRANS_SIZE;
993 			rem = PCH_DMA_TRANS_SIZE;
994 		}
995 		size = PCH_DMA_TRANS_SIZE;
996 	} else {
997 		num = 1;
998 		size = data->bpw_len;
999 		rem = data->bpw_len;
1000 	}
1001 	dev_dbg(&data->master->dev, "%s num=%d size=%d rem=%d\n",
1002 		__func__, num, size, rem);
1003 	spin_lock_irqsave(&data->lock, flags);
1004 
1005 	/* set receive fifo threshold and transmit fifo threshold */
1006 	pch_spi_setclr_reg(data->master, PCH_SPCR,
1007 			   ((size - 1) << SPCR_RFIC_FIELD) |
1008 			   (PCH_TX_THOLD << SPCR_TFIC_FIELD),
1009 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS);
1010 
1011 	spin_unlock_irqrestore(&data->lock, flags);
1012 
1013 	/* RX */
1014 	dma->sg_rx_p = kmalloc_array(num, sizeof(*dma->sg_rx_p), GFP_ATOMIC);
1015 	if (!dma->sg_rx_p)
1016 		return;
1017 
1018 	sg_init_table(dma->sg_rx_p, num); /* Initialize SG table */
1019 	/* offset, length setting */
1020 	sg = dma->sg_rx_p;
1021 	for (i = 0; i < num; i++, sg++) {
1022 		if (i == (num - 2)) {
1023 			sg->offset = size * i;
1024 			sg->offset = sg->offset * (*bpw / 8);
1025 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), rem,
1026 				    sg->offset);
1027 			sg_dma_len(sg) = rem;
1028 		} else if (i == (num - 1)) {
1029 			sg->offset = size * (i - 1) + rem;
1030 			sg->offset = sg->offset * (*bpw / 8);
1031 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
1032 				    sg->offset);
1033 			sg_dma_len(sg) = size;
1034 		} else {
1035 			sg->offset = size * i;
1036 			sg->offset = sg->offset * (*bpw / 8);
1037 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
1038 				    sg->offset);
1039 			sg_dma_len(sg) = size;
1040 		}
1041 		sg_dma_address(sg) = dma->rx_buf_dma + sg->offset;
1042 	}
1043 	sg = dma->sg_rx_p;
1044 	desc_rx = dmaengine_prep_slave_sg(dma->chan_rx, sg,
1045 					num, DMA_DEV_TO_MEM,
1046 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1047 	if (!desc_rx) {
1048 		dev_err(&data->master->dev,
1049 			"%s:dmaengine_prep_slave_sg Failed\n", __func__);
1050 		return;
1051 	}
1052 	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_FROM_DEVICE);
1053 	desc_rx->callback = pch_dma_rx_complete;
1054 	desc_rx->callback_param = data;
1055 	dma->nent = num;
1056 	dma->desc_rx = desc_rx;
1057 
1058 	/* Calculate Tx parameter for DMA transmitting */
1059 	if (data->bpw_len > PCH_MAX_FIFO_DEPTH) {
1060 		head = PCH_MAX_FIFO_DEPTH - PCH_DMA_TRANS_SIZE;
1061 		if (data->bpw_len % PCH_DMA_TRANS_SIZE > 4) {
1062 			num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
1063 			rem = data->bpw_len % PCH_DMA_TRANS_SIZE - head;
1064 		} else {
1065 			num = data->bpw_len / PCH_DMA_TRANS_SIZE;
1066 			rem = data->bpw_len % PCH_DMA_TRANS_SIZE +
1067 			      PCH_DMA_TRANS_SIZE - head;
1068 		}
1069 		size = PCH_DMA_TRANS_SIZE;
1070 	} else {
1071 		num = 1;
1072 		size = data->bpw_len;
1073 		rem = data->bpw_len;
1074 		head = 0;
1075 	}
1076 
1077 	dma->sg_tx_p = kmalloc_array(num, sizeof(*dma->sg_tx_p), GFP_ATOMIC);
1078 	if (!dma->sg_tx_p)
1079 		return;
1080 
1081 	sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */
1082 	/* offset, length setting */
1083 	sg = dma->sg_tx_p;
1084 	for (i = 0; i < num; i++, sg++) {
1085 		if (i == 0) {
1086 			sg->offset = 0;
1087 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size + head,
1088 				    sg->offset);
1089 			sg_dma_len(sg) = size + head;
1090 		} else if (i == (num - 1)) {
1091 			sg->offset = head + size * i;
1092 			sg->offset = sg->offset * (*bpw / 8);
1093 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), rem,
1094 				    sg->offset);
1095 			sg_dma_len(sg) = rem;
1096 		} else {
1097 			sg->offset = head + size * i;
1098 			sg->offset = sg->offset * (*bpw / 8);
1099 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size,
1100 				    sg->offset);
1101 			sg_dma_len(sg) = size;
1102 		}
1103 		sg_dma_address(sg) = dma->tx_buf_dma + sg->offset;
1104 	}
1105 	sg = dma->sg_tx_p;
1106 	desc_tx = dmaengine_prep_slave_sg(dma->chan_tx,
1107 					sg, num, DMA_MEM_TO_DEV,
1108 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1109 	if (!desc_tx) {
1110 		dev_err(&data->master->dev,
1111 			"%s:dmaengine_prep_slave_sg Failed\n", __func__);
1112 		return;
1113 	}
1114 	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_TO_DEVICE);
1115 	desc_tx->callback = NULL;
1116 	desc_tx->callback_param = data;
1117 	dma->nent = num;
1118 	dma->desc_tx = desc_tx;
1119 
1120 	dev_dbg(&data->master->dev, "%s:Pulling down SSN low - writing 0x2 to SSNXCR\n", __func__);
1121 
1122 	spin_lock_irqsave(&data->lock, flags);
1123 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
1124 	desc_rx->tx_submit(desc_rx);
1125 	desc_tx->tx_submit(desc_tx);
1126 	spin_unlock_irqrestore(&data->lock, flags);
1127 
1128 	/* reset transfer complete flag */
1129 	data->transfer_complete = false;
1130 }
1131 
1132 static void pch_spi_process_messages(struct work_struct *pwork)
1133 {
1134 	struct spi_message *pmsg, *tmp;
1135 	struct pch_spi_data *data;
1136 	int bpw;
1137 
1138 	data = container_of(pwork, struct pch_spi_data, work);
1139 	dev_dbg(&data->master->dev, "%s data initialized\n", __func__);
1140 
1141 	spin_lock(&data->lock);
1142 	/* check if suspend has been initiated;if yes flush queue */
1143 	if (data->board_dat->suspend_sts || (data->status == STATUS_EXITING)) {
1144 		dev_dbg(&data->master->dev,
1145 			"%s suspend/remove initiated, flushing queue\n", __func__);
1146 		list_for_each_entry_safe(pmsg, tmp, data->queue.next, queue) {
1147 			pmsg->status = -EIO;
1148 
1149 			if (pmsg->complete) {
1150 				spin_unlock(&data->lock);
1151 				pmsg->complete(pmsg->context);
1152 				spin_lock(&data->lock);
1153 			}
1154 
1155 			/* delete from queue */
1156 			list_del_init(&pmsg->queue);
1157 		}
1158 
1159 		spin_unlock(&data->lock);
1160 		return;
1161 	}
1162 
1163 	data->bcurrent_msg_processing = true;
1164 	dev_dbg(&data->master->dev,
1165 		"%s Set data->bcurrent_msg_processing= true\n", __func__);
1166 
1167 	/* Get the message from the queue and delete it from there. */
1168 	data->current_msg = list_entry(data->queue.next, struct spi_message,
1169 					queue);
1170 
1171 	list_del_init(&data->current_msg->queue);
1172 
1173 	data->current_msg->status = 0;
1174 
1175 	pch_spi_select_chip(data, data->current_msg->spi);
1176 
1177 	spin_unlock(&data->lock);
1178 
1179 	if (data->use_dma)
1180 		pch_spi_request_dma(data,
1181 				    data->current_msg->spi->bits_per_word);
1182 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
1183 	do {
1184 		int cnt;
1185 		/* If we are already processing a message get the next
1186 		transfer structure from the message otherwise retrieve
1187 		the 1st transfer request from the message. */
1188 		spin_lock(&data->lock);
1189 		if (data->cur_trans == NULL) {
1190 			data->cur_trans =
1191 				list_entry(data->current_msg->transfers.next,
1192 					   struct spi_transfer, transfer_list);
1193 			dev_dbg(&data->master->dev,
1194 				"%s :Getting 1st transfer message\n",
1195 				__func__);
1196 		} else {
1197 			data->cur_trans =
1198 				list_entry(data->cur_trans->transfer_list.next,
1199 					   struct spi_transfer, transfer_list);
1200 			dev_dbg(&data->master->dev,
1201 				"%s :Getting next transfer message\n",
1202 				__func__);
1203 		}
1204 		spin_unlock(&data->lock);
1205 
1206 		if (!data->cur_trans->len)
1207 			goto out;
1208 		cnt = (data->cur_trans->len - 1) / PCH_BUF_SIZE + 1;
1209 		data->save_total_len = data->cur_trans->len;
1210 		if (data->use_dma) {
1211 			int i;
1212 			char *save_rx_buf = data->cur_trans->rx_buf;
1213 
1214 			for (i = 0; i < cnt; i++) {
1215 				pch_spi_handle_dma(data, &bpw);
1216 				if (!pch_spi_start_transfer(data)) {
1217 					data->transfer_complete = true;
1218 					data->current_msg->status = -EIO;
1219 					data->current_msg->complete
1220 						   (data->current_msg->context);
1221 					data->bcurrent_msg_processing = false;
1222 					data->current_msg = NULL;
1223 					data->cur_trans = NULL;
1224 					goto out;
1225 				}
1226 				pch_spi_copy_rx_data_for_dma(data, bpw);
1227 			}
1228 			data->cur_trans->rx_buf = save_rx_buf;
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->cur_trans->len = data->save_total_len;
1240 		data->current_msg->actual_length += data->cur_trans->len;
1241 
1242 		dev_dbg(&data->master->dev,
1243 			"%s:data->current_msg->actual_length=%d\n",
1244 			__func__, data->current_msg->actual_length);
1245 
1246 		spi_transfer_delay_exec(data->cur_trans);
1247 
1248 		spin_lock(&data->lock);
1249 
1250 		/* No more transfer in this message. */
1251 		if ((data->cur_trans->transfer_list.next) ==
1252 		    &(data->current_msg->transfers)) {
1253 			pch_spi_nomore_transfer(data);
1254 		}
1255 
1256 		spin_unlock(&data->lock);
1257 
1258 	} while (data->cur_trans != NULL);
1259 
1260 out:
1261 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_HIGH);
1262 	if (data->use_dma)
1263 		pch_spi_release_dma(data);
1264 }
1265 
1266 static void pch_spi_free_resources(struct pch_spi_board_data *board_dat,
1267 				   struct pch_spi_data *data)
1268 {
1269 	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
1270 
1271 	flush_work(&data->work);
1272 }
1273 
1274 static int pch_spi_get_resources(struct pch_spi_board_data *board_dat,
1275 				 struct pch_spi_data *data)
1276 {
1277 	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
1278 
1279 	/* reset PCH SPI h/w */
1280 	pch_spi_reset(data->master);
1281 	dev_dbg(&board_dat->pdev->dev,
1282 		"%s pch_spi_reset invoked successfully\n", __func__);
1283 
1284 	dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true\n", __func__);
1285 
1286 	return 0;
1287 }
1288 
1289 static void pch_free_dma_buf(struct pch_spi_board_data *board_dat,
1290 			     struct pch_spi_data *data)
1291 {
1292 	struct pch_spi_dma_ctrl *dma;
1293 
1294 	dma = &data->dma;
1295 	if (dma->tx_buf_dma)
1296 		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
1297 				  dma->tx_buf_virt, dma->tx_buf_dma);
1298 	if (dma->rx_buf_dma)
1299 		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
1300 				  dma->rx_buf_virt, dma->rx_buf_dma);
1301 }
1302 
1303 static int pch_alloc_dma_buf(struct pch_spi_board_data *board_dat,
1304 			      struct pch_spi_data *data)
1305 {
1306 	struct pch_spi_dma_ctrl *dma;
1307 	int ret;
1308 
1309 	dma = &data->dma;
1310 	ret = 0;
1311 	/* Get Consistent memory for Tx DMA */
1312 	dma->tx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
1313 				PCH_BUF_SIZE, &dma->tx_buf_dma, GFP_KERNEL);
1314 	if (!dma->tx_buf_virt)
1315 		ret = -ENOMEM;
1316 
1317 	/* Get Consistent memory for Rx DMA */
1318 	dma->rx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
1319 				PCH_BUF_SIZE, &dma->rx_buf_dma, GFP_KERNEL);
1320 	if (!dma->rx_buf_virt)
1321 		ret = -ENOMEM;
1322 
1323 	return ret;
1324 }
1325 
1326 static int pch_spi_pd_probe(struct platform_device *plat_dev)
1327 {
1328 	int ret;
1329 	struct spi_master *master;
1330 	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
1331 	struct pch_spi_data *data;
1332 
1333 	dev_dbg(&plat_dev->dev, "%s:debug\n", __func__);
1334 
1335 	master = spi_alloc_master(&board_dat->pdev->dev,
1336 				  sizeof(struct pch_spi_data));
1337 	if (!master) {
1338 		dev_err(&plat_dev->dev, "spi_alloc_master[%d] failed.\n",
1339 			plat_dev->id);
1340 		return -ENOMEM;
1341 	}
1342 
1343 	data = spi_master_get_devdata(master);
1344 	data->master = master;
1345 
1346 	platform_set_drvdata(plat_dev, data);
1347 
1348 	/* baseaddress + address offset) */
1349 	data->io_base_addr = pci_resource_start(board_dat->pdev, 1) +
1350 					 PCH_ADDRESS_SIZE * plat_dev->id;
1351 	data->io_remap_addr = pci_iomap(board_dat->pdev, 1, 0);
1352 	if (!data->io_remap_addr) {
1353 		dev_err(&plat_dev->dev, "%s pci_iomap failed\n", __func__);
1354 		ret = -ENOMEM;
1355 		goto err_pci_iomap;
1356 	}
1357 	data->io_remap_addr += PCH_ADDRESS_SIZE * plat_dev->id;
1358 
1359 	dev_dbg(&plat_dev->dev, "[ch%d] remap_addr=%p\n",
1360 		plat_dev->id, data->io_remap_addr);
1361 
1362 	/* initialize members of SPI master */
1363 	master->num_chipselect = PCH_MAX_CS;
1364 	master->transfer = pch_spi_transfer;
1365 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1366 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
1367 	master->max_speed_hz = PCH_MAX_BAUDRATE;
1368 
1369 	data->board_dat = board_dat;
1370 	data->plat_dev = plat_dev;
1371 	data->n_curnt_chip = 255;
1372 	data->status = STATUS_RUNNING;
1373 	data->ch = plat_dev->id;
1374 	data->use_dma = use_dma;
1375 
1376 	INIT_LIST_HEAD(&data->queue);
1377 	spin_lock_init(&data->lock);
1378 	INIT_WORK(&data->work, pch_spi_process_messages);
1379 	init_waitqueue_head(&data->wait);
1380 
1381 	ret = pch_spi_get_resources(board_dat, data);
1382 	if (ret) {
1383 		dev_err(&plat_dev->dev, "%s fail(retval=%d)\n", __func__, ret);
1384 		goto err_spi_get_resources;
1385 	}
1386 
1387 	ret = request_irq(board_dat->pdev->irq, pch_spi_handler,
1388 			  IRQF_SHARED, KBUILD_MODNAME, data);
1389 	if (ret) {
1390 		dev_err(&plat_dev->dev,
1391 			"%s request_irq failed\n", __func__);
1392 		goto err_request_irq;
1393 	}
1394 	data->irq_reg_sts = true;
1395 
1396 	pch_spi_set_master_mode(master);
1397 
1398 	if (use_dma) {
1399 		dev_info(&plat_dev->dev, "Use DMA for data transfers\n");
1400 		ret = pch_alloc_dma_buf(board_dat, data);
1401 		if (ret)
1402 			goto err_spi_register_master;
1403 	}
1404 
1405 	ret = spi_register_master(master);
1406 	if (ret != 0) {
1407 		dev_err(&plat_dev->dev,
1408 			"%s spi_register_master FAILED\n", __func__);
1409 		goto err_spi_register_master;
1410 	}
1411 
1412 	return 0;
1413 
1414 err_spi_register_master:
1415 	pch_free_dma_buf(board_dat, data);
1416 	free_irq(board_dat->pdev->irq, data);
1417 err_request_irq:
1418 	pch_spi_free_resources(board_dat, data);
1419 err_spi_get_resources:
1420 	pci_iounmap(board_dat->pdev, data->io_remap_addr);
1421 err_pci_iomap:
1422 	spi_master_put(master);
1423 
1424 	return ret;
1425 }
1426 
1427 static int pch_spi_pd_remove(struct platform_device *plat_dev)
1428 {
1429 	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
1430 	struct pch_spi_data *data = platform_get_drvdata(plat_dev);
1431 	int count;
1432 	unsigned long flags;
1433 
1434 	dev_dbg(&plat_dev->dev, "%s:[ch%d] irq=%d\n",
1435 		__func__, plat_dev->id, board_dat->pdev->irq);
1436 
1437 	if (use_dma)
1438 		pch_free_dma_buf(board_dat, data);
1439 
1440 	/* check for any pending messages; no action is taken if the queue
1441 	 * is still full; but at least we tried.  Unload anyway */
1442 	count = 500;
1443 	spin_lock_irqsave(&data->lock, flags);
1444 	data->status = STATUS_EXITING;
1445 	while ((list_empty(&data->queue) == 0) && --count) {
1446 		dev_dbg(&board_dat->pdev->dev, "%s :queue not empty\n",
1447 			__func__);
1448 		spin_unlock_irqrestore(&data->lock, flags);
1449 		msleep(PCH_SLEEP_TIME);
1450 		spin_lock_irqsave(&data->lock, flags);
1451 	}
1452 	spin_unlock_irqrestore(&data->lock, flags);
1453 
1454 	pch_spi_free_resources(board_dat, data);
1455 	/* disable interrupts & free IRQ */
1456 	if (data->irq_reg_sts) {
1457 		/* disable interrupts */
1458 		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
1459 		data->irq_reg_sts = false;
1460 		free_irq(board_dat->pdev->irq, data);
1461 	}
1462 
1463 	pci_iounmap(board_dat->pdev, data->io_remap_addr);
1464 	spi_unregister_master(data->master);
1465 
1466 	return 0;
1467 }
1468 #ifdef CONFIG_PM
1469 static int pch_spi_pd_suspend(struct platform_device *pd_dev,
1470 			      pm_message_t state)
1471 {
1472 	u8 count;
1473 	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
1474 	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
1475 
1476 	dev_dbg(&pd_dev->dev, "%s ENTRY\n", __func__);
1477 
1478 	if (!board_dat) {
1479 		dev_err(&pd_dev->dev,
1480 			"%s pci_get_drvdata returned NULL\n", __func__);
1481 		return -EFAULT;
1482 	}
1483 
1484 	/* check if the current message is processed:
1485 	   Only after thats done the transfer will be suspended */
1486 	count = 255;
1487 	while ((--count) > 0) {
1488 		if (!(data->bcurrent_msg_processing))
1489 			break;
1490 		msleep(PCH_SLEEP_TIME);
1491 	}
1492 
1493 	/* Free IRQ */
1494 	if (data->irq_reg_sts) {
1495 		/* disable all interrupts */
1496 		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
1497 		pch_spi_reset(data->master);
1498 		free_irq(board_dat->pdev->irq, data);
1499 
1500 		data->irq_reg_sts = false;
1501 		dev_dbg(&pd_dev->dev,
1502 			"%s free_irq invoked successfully.\n", __func__);
1503 	}
1504 
1505 	return 0;
1506 }
1507 
1508 static int pch_spi_pd_resume(struct platform_device *pd_dev)
1509 {
1510 	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
1511 	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
1512 	int retval;
1513 
1514 	if (!board_dat) {
1515 		dev_err(&pd_dev->dev,
1516 			"%s pci_get_drvdata returned NULL\n", __func__);
1517 		return -EFAULT;
1518 	}
1519 
1520 	if (!data->irq_reg_sts) {
1521 		/* register IRQ */
1522 		retval = request_irq(board_dat->pdev->irq, pch_spi_handler,
1523 				     IRQF_SHARED, KBUILD_MODNAME, data);
1524 		if (retval < 0) {
1525 			dev_err(&pd_dev->dev,
1526 				"%s request_irq failed\n", __func__);
1527 			return retval;
1528 		}
1529 
1530 		/* reset PCH SPI h/w */
1531 		pch_spi_reset(data->master);
1532 		pch_spi_set_master_mode(data->master);
1533 		data->irq_reg_sts = true;
1534 	}
1535 	return 0;
1536 }
1537 #else
1538 #define pch_spi_pd_suspend NULL
1539 #define pch_spi_pd_resume NULL
1540 #endif
1541 
1542 static struct platform_driver pch_spi_pd_driver = {
1543 	.driver = {
1544 		.name = "pch-spi",
1545 	},
1546 	.probe = pch_spi_pd_probe,
1547 	.remove = pch_spi_pd_remove,
1548 	.suspend = pch_spi_pd_suspend,
1549 	.resume = pch_spi_pd_resume
1550 };
1551 
1552 static int pch_spi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1553 {
1554 	struct pch_spi_board_data *board_dat;
1555 	struct platform_device *pd_dev = NULL;
1556 	int retval;
1557 	int i;
1558 	struct pch_pd_dev_save *pd_dev_save;
1559 
1560 	pd_dev_save = kzalloc(sizeof(*pd_dev_save), GFP_KERNEL);
1561 	if (!pd_dev_save)
1562 		return -ENOMEM;
1563 
1564 	board_dat = kzalloc(sizeof(*board_dat), GFP_KERNEL);
1565 	if (!board_dat) {
1566 		retval = -ENOMEM;
1567 		goto err_no_mem;
1568 	}
1569 
1570 	retval = pci_request_regions(pdev, KBUILD_MODNAME);
1571 	if (retval) {
1572 		dev_err(&pdev->dev, "%s request_region failed\n", __func__);
1573 		goto pci_request_regions;
1574 	}
1575 
1576 	board_dat->pdev = pdev;
1577 	board_dat->num = id->driver_data;
1578 	pd_dev_save->num = id->driver_data;
1579 	pd_dev_save->board_dat = board_dat;
1580 
1581 	retval = pci_enable_device(pdev);
1582 	if (retval) {
1583 		dev_err(&pdev->dev, "%s pci_enable_device failed\n", __func__);
1584 		goto pci_enable_device;
1585 	}
1586 
1587 	for (i = 0; i < board_dat->num; i++) {
1588 		pd_dev = platform_device_alloc("pch-spi", i);
1589 		if (!pd_dev) {
1590 			dev_err(&pdev->dev, "platform_device_alloc failed\n");
1591 			retval = -ENOMEM;
1592 			goto err_platform_device;
1593 		}
1594 		pd_dev_save->pd_save[i] = pd_dev;
1595 		pd_dev->dev.parent = &pdev->dev;
1596 
1597 		retval = platform_device_add_data(pd_dev, board_dat,
1598 						  sizeof(*board_dat));
1599 		if (retval) {
1600 			dev_err(&pdev->dev,
1601 				"platform_device_add_data failed\n");
1602 			platform_device_put(pd_dev);
1603 			goto err_platform_device;
1604 		}
1605 
1606 		retval = platform_device_add(pd_dev);
1607 		if (retval) {
1608 			dev_err(&pdev->dev, "platform_device_add failed\n");
1609 			platform_device_put(pd_dev);
1610 			goto err_platform_device;
1611 		}
1612 	}
1613 
1614 	pci_set_drvdata(pdev, pd_dev_save);
1615 
1616 	return 0;
1617 
1618 err_platform_device:
1619 	while (--i >= 0)
1620 		platform_device_unregister(pd_dev_save->pd_save[i]);
1621 	pci_disable_device(pdev);
1622 pci_enable_device:
1623 	pci_release_regions(pdev);
1624 pci_request_regions:
1625 	kfree(board_dat);
1626 err_no_mem:
1627 	kfree(pd_dev_save);
1628 
1629 	return retval;
1630 }
1631 
1632 static void pch_spi_remove(struct pci_dev *pdev)
1633 {
1634 	int i;
1635 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1636 
1637 	dev_dbg(&pdev->dev, "%s ENTRY:pdev=%p\n", __func__, pdev);
1638 
1639 	for (i = 0; i < pd_dev_save->num; i++)
1640 		platform_device_unregister(pd_dev_save->pd_save[i]);
1641 
1642 	pci_disable_device(pdev);
1643 	pci_release_regions(pdev);
1644 	kfree(pd_dev_save->board_dat);
1645 	kfree(pd_dev_save);
1646 }
1647 
1648 static int __maybe_unused pch_spi_suspend(struct device *dev)
1649 {
1650 	struct pch_pd_dev_save *pd_dev_save = dev_get_drvdata(dev);
1651 
1652 	dev_dbg(dev, "%s ENTRY\n", __func__);
1653 
1654 	pd_dev_save->board_dat->suspend_sts = true;
1655 
1656 	return 0;
1657 }
1658 
1659 static int __maybe_unused pch_spi_resume(struct device *dev)
1660 {
1661 	struct pch_pd_dev_save *pd_dev_save = dev_get_drvdata(dev);
1662 
1663 	dev_dbg(dev, "%s ENTRY\n", __func__);
1664 
1665 	/* set suspend status to false */
1666 	pd_dev_save->board_dat->suspend_sts = false;
1667 
1668 	return 0;
1669 }
1670 
1671 static SIMPLE_DEV_PM_OPS(pch_spi_pm_ops, pch_spi_suspend, pch_spi_resume);
1672 
1673 static struct pci_driver pch_spi_pcidev_driver = {
1674 	.name = "pch_spi",
1675 	.id_table = pch_spi_pcidev_id,
1676 	.probe = pch_spi_probe,
1677 	.remove = pch_spi_remove,
1678 	.driver.pm = &pch_spi_pm_ops,
1679 };
1680 
1681 static int __init pch_spi_init(void)
1682 {
1683 	int ret;
1684 	ret = platform_driver_register(&pch_spi_pd_driver);
1685 	if (ret)
1686 		return ret;
1687 
1688 	ret = pci_register_driver(&pch_spi_pcidev_driver);
1689 	if (ret) {
1690 		platform_driver_unregister(&pch_spi_pd_driver);
1691 		return ret;
1692 	}
1693 
1694 	return 0;
1695 }
1696 module_init(pch_spi_init);
1697 
1698 static void __exit pch_spi_exit(void)
1699 {
1700 	pci_unregister_driver(&pch_spi_pcidev_driver);
1701 	platform_driver_unregister(&pch_spi_pd_driver);
1702 }
1703 module_exit(pch_spi_exit);
1704 
1705 module_param(use_dma, int, 0644);
1706 MODULE_PARM_DESC(use_dma,
1707 		 "to use DMA for data transfers pass 1 else 0; default 1");
1708 
1709 MODULE_LICENSE("GPL");
1710 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semiconductor ML7xxx IOH SPI Driver");
1711 MODULE_DEVICE_TABLE(pci, pch_spi_pcidev_id);
1712 
1713