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