xref: /linux/drivers/spi/spi-topcliff-pch.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 /*
2  * SPI bus driver for the Topcliff PCH used by Intel SoCs
3  *
4  * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/pci.h>
18 #include <linux/wait.h>
19 #include <linux/spi/spi.h>
20 #include <linux/interrupt.h>
21 #include <linux/sched.h>
22 #include <linux/spi/spidev.h>
23 #include <linux/module.h>
24 #include <linux/device.h>
25 #include <linux/platform_device.h>
26 
27 #include <linux/dmaengine.h>
28 #include <linux/pch_dma.h>
29 
30 /* Register offsets */
31 #define PCH_SPCR		0x00	/* SPI control register */
32 #define PCH_SPBRR		0x04	/* SPI baud rate register */
33 #define PCH_SPSR		0x08	/* SPI status register */
34 #define PCH_SPDWR		0x0C	/* SPI write data register */
35 #define PCH_SPDRR		0x10	/* SPI read data register */
36 #define PCH_SSNXCR		0x18	/* SSN Expand Control Register */
37 #define PCH_SRST		0x1C	/* SPI reset register */
38 #define PCH_ADDRESS_SIZE	0x20
39 
40 #define PCH_SPSR_TFD		0x000007C0
41 #define PCH_SPSR_RFD		0x0000F800
42 
43 #define PCH_READABLE(x)		(((x) & PCH_SPSR_RFD)>>11)
44 #define PCH_WRITABLE(x)		(((x) & PCH_SPSR_TFD)>>6)
45 
46 #define PCH_RX_THOLD		7
47 #define PCH_RX_THOLD_MAX	15
48 
49 #define PCH_TX_THOLD		2
50 
51 #define PCH_MAX_BAUDRATE	5000000
52 #define PCH_MAX_FIFO_DEPTH	16
53 
54 #define STATUS_RUNNING		1
55 #define STATUS_EXITING		2
56 #define PCH_SLEEP_TIME		10
57 
58 #define SSN_LOW			0x02U
59 #define SSN_HIGH		0x03U
60 #define SSN_NO_CONTROL		0x00U
61 #define PCH_MAX_CS		0xFF
62 #define PCI_DEVICE_ID_GE_SPI	0x8816
63 
64 #define SPCR_SPE_BIT		(1 << 0)
65 #define SPCR_MSTR_BIT		(1 << 1)
66 #define SPCR_LSBF_BIT		(1 << 4)
67 #define SPCR_CPHA_BIT		(1 << 5)
68 #define SPCR_CPOL_BIT		(1 << 6)
69 #define SPCR_TFIE_BIT		(1 << 8)
70 #define SPCR_RFIE_BIT		(1 << 9)
71 #define SPCR_FIE_BIT		(1 << 10)
72 #define SPCR_ORIE_BIT		(1 << 11)
73 #define SPCR_MDFIE_BIT		(1 << 12)
74 #define SPCR_FICLR_BIT		(1 << 24)
75 #define SPSR_TFI_BIT		(1 << 0)
76 #define SPSR_RFI_BIT		(1 << 1)
77 #define SPSR_FI_BIT		(1 << 2)
78 #define SPSR_ORF_BIT		(1 << 3)
79 #define SPBRR_SIZE_BIT		(1 << 10)
80 
81 #define PCH_ALL			(SPCR_TFIE_BIT|SPCR_RFIE_BIT|SPCR_FIE_BIT|\
82 				SPCR_ORIE_BIT|SPCR_MDFIE_BIT)
83 
84 #define SPCR_RFIC_FIELD		20
85 #define SPCR_TFIC_FIELD		16
86 
87 #define MASK_SPBRR_SPBR_BITS	((1 << 10) - 1)
88 #define MASK_RFIC_SPCR_BITS	(0xf << SPCR_RFIC_FIELD)
89 #define MASK_TFIC_SPCR_BITS	(0xf << SPCR_TFIC_FIELD)
90 
91 #define PCH_CLOCK_HZ		50000000
92 #define PCH_MAX_SPBR		1023
93 
94 /* Definition for ML7213/ML7223/ML7831 by LAPIS Semiconductor */
95 #define PCI_VENDOR_ID_ROHM		0x10DB
96 #define PCI_DEVICE_ID_ML7213_SPI	0x802c
97 #define PCI_DEVICE_ID_ML7223_SPI	0x800F
98 #define PCI_DEVICE_ID_ML7831_SPI	0x8816
99 
100 /*
101  * Set the number of SPI instance max
102  * Intel EG20T PCH :		1ch
103  * LAPIS Semiconductor ML7213 IOH :	2ch
104  * LAPIS Semiconductor ML7223 IOH :	1ch
105  * LAPIS Semiconductor ML7831 IOH :	1ch
106 */
107 #define PCH_SPI_MAX_DEV			2
108 
109 #define PCH_BUF_SIZE		4096
110 #define PCH_DMA_TRANS_SIZE	12
111 
112 static int use_dma = 1;
113 
114 struct pch_spi_dma_ctrl {
115 	struct dma_async_tx_descriptor	*desc_tx;
116 	struct dma_async_tx_descriptor	*desc_rx;
117 	struct pch_dma_slave		param_tx;
118 	struct pch_dma_slave		param_rx;
119 	struct dma_chan		*chan_tx;
120 	struct dma_chan		*chan_rx;
121 	struct scatterlist		*sg_tx_p;
122 	struct scatterlist		*sg_rx_p;
123 	struct scatterlist		sg_tx;
124 	struct scatterlist		sg_rx;
125 	int				nent;
126 	void				*tx_buf_virt;
127 	void				*rx_buf_virt;
128 	dma_addr_t			tx_buf_dma;
129 	dma_addr_t			rx_buf_dma;
130 };
131 /**
132  * struct pch_spi_data - Holds the SPI channel specific details
133  * @io_remap_addr:		The remapped PCI base address
134  * @master:			Pointer to the SPI master structure
135  * @work:			Reference to work queue handler
136  * @wk:				Workqueue for carrying out execution of the
137  *				requests
138  * @wait:			Wait queue for waking up upon receiving an
139  *				interrupt.
140  * @transfer_complete:		Status of SPI Transfer
141  * @bcurrent_msg_processing:	Status flag for message processing
142  * @lock:			Lock for protecting this structure
143  * @queue:			SPI Message queue
144  * @status:			Status of the SPI driver
145  * @bpw_len:			Length of data to be transferred in bits per
146  *				word
147  * @transfer_active:		Flag showing active transfer
148  * @tx_index:			Transmit data count; for bookkeeping during
149  *				transfer
150  * @rx_index:			Receive data count; for bookkeeping during
151  *				transfer
152  * @tx_buff:			Buffer for data to be transmitted
153  * @rx_index:			Buffer for Received data
154  * @n_curnt_chip:		The chip number that this SPI driver currently
155  *				operates on
156  * @current_chip:		Reference to the current chip that this SPI
157  *				driver currently operates on
158  * @current_msg:		The current message that this SPI driver is
159  *				handling
160  * @cur_trans:			The current transfer that this SPI driver is
161  *				handling
162  * @board_dat:			Reference to the SPI device data structure
163  * @plat_dev:			platform_device structure
164  * @ch:				SPI channel number
165  * @irq_reg_sts:		Status of IRQ registration
166  */
167 struct pch_spi_data {
168 	void __iomem *io_remap_addr;
169 	unsigned long io_base_addr;
170 	struct spi_master *master;
171 	struct work_struct work;
172 	struct workqueue_struct *wk;
173 	wait_queue_head_t wait;
174 	u8 transfer_complete;
175 	u8 bcurrent_msg_processing;
176 	spinlock_t lock;
177 	struct list_head queue;
178 	u8 status;
179 	u32 bpw_len;
180 	u8 transfer_active;
181 	u32 tx_index;
182 	u32 rx_index;
183 	u16 *pkt_tx_buff;
184 	u16 *pkt_rx_buff;
185 	u8 n_curnt_chip;
186 	struct spi_device *current_chip;
187 	struct spi_message *current_msg;
188 	struct spi_transfer *cur_trans;
189 	struct pch_spi_board_data *board_dat;
190 	struct platform_device	*plat_dev;
191 	int ch;
192 	struct pch_spi_dma_ctrl dma;
193 	int use_dma;
194 	u8 irq_reg_sts;
195 	int save_total_len;
196 };
197 
198 /**
199  * struct pch_spi_board_data - Holds the SPI device specific details
200  * @pdev:		Pointer to the PCI device
201  * @suspend_sts:	Status of suspend
202  * @num:		The number of SPI device instance
203  */
204 struct pch_spi_board_data {
205 	struct pci_dev *pdev;
206 	u8 suspend_sts;
207 	int num;
208 };
209 
210 struct pch_pd_dev_save {
211 	int num;
212 	struct platform_device *pd_save[PCH_SPI_MAX_DEV];
213 	struct pch_spi_board_data *board_dat;
214 };
215 
216 static const struct pci_device_id pch_spi_pcidev_id[] = {
217 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_GE_SPI),    1, },
218 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_SPI), 2, },
219 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_SPI), 1, },
220 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_SPI), 1, },
221 	{ }
222 };
223 
224 /**
225  * pch_spi_writereg() - Performs  register writes
226  * @master:	Pointer to struct spi_master.
227  * @idx:	Register offset.
228  * @val:	Value to be written to register.
229  */
230 static inline void pch_spi_writereg(struct spi_master *master, int idx, u32 val)
231 {
232 	struct pch_spi_data *data = spi_master_get_devdata(master);
233 	iowrite32(val, (data->io_remap_addr + idx));
234 }
235 
236 /**
237  * pch_spi_readreg() - Performs register reads
238  * @master:	Pointer to struct spi_master.
239  * @idx:	Register offset.
240  */
241 static inline u32 pch_spi_readreg(struct spi_master *master, int idx)
242 {
243 	struct pch_spi_data *data = spi_master_get_devdata(master);
244 	return ioread32(data->io_remap_addr + idx);
245 }
246 
247 static inline void pch_spi_setclr_reg(struct spi_master *master, int idx,
248 				      u32 set, u32 clr)
249 {
250 	u32 tmp = pch_spi_readreg(master, idx);
251 	tmp = (tmp & ~clr) | set;
252 	pch_spi_writereg(master, idx, tmp);
253 }
254 
255 static void pch_spi_set_master_mode(struct spi_master *master)
256 {
257 	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_MSTR_BIT, 0);
258 }
259 
260 /**
261  * pch_spi_clear_fifo() - Clears the Transmit and Receive FIFOs
262  * @master:	Pointer to struct spi_master.
263  */
264 static void pch_spi_clear_fifo(struct spi_master *master)
265 {
266 	pch_spi_setclr_reg(master, PCH_SPCR, SPCR_FICLR_BIT, 0);
267 	pch_spi_setclr_reg(master, PCH_SPCR, 0, SPCR_FICLR_BIT);
268 }
269 
270 static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
271 				void __iomem *io_remap_addr)
272 {
273 	u32 n_read, tx_index, rx_index, bpw_len;
274 	u16 *pkt_rx_buffer, *pkt_tx_buff;
275 	int read_cnt;
276 	u32 reg_spcr_val;
277 	void __iomem *spsr;
278 	void __iomem *spdrr;
279 	void __iomem *spdwr;
280 
281 	spsr = io_remap_addr + PCH_SPSR;
282 	iowrite32(reg_spsr_val, spsr);
283 
284 	if (data->transfer_active) {
285 		rx_index = data->rx_index;
286 		tx_index = data->tx_index;
287 		bpw_len = data->bpw_len;
288 		pkt_rx_buffer = data->pkt_rx_buff;
289 		pkt_tx_buff = data->pkt_tx_buff;
290 
291 		spdrr = io_remap_addr + PCH_SPDRR;
292 		spdwr = io_remap_addr + PCH_SPDWR;
293 
294 		n_read = PCH_READABLE(reg_spsr_val);
295 
296 		for (read_cnt = 0; (read_cnt < n_read); read_cnt++) {
297 			pkt_rx_buffer[rx_index++] = ioread32(spdrr);
298 			if (tx_index < bpw_len)
299 				iowrite32(pkt_tx_buff[tx_index++], spdwr);
300 		}
301 
302 		/* disable RFI if not needed */
303 		if ((bpw_len - rx_index) <= PCH_MAX_FIFO_DEPTH) {
304 			reg_spcr_val = ioread32(io_remap_addr + PCH_SPCR);
305 			reg_spcr_val &= ~SPCR_RFIE_BIT; /* disable RFI */
306 
307 			/* reset rx threshold */
308 			reg_spcr_val &= ~MASK_RFIC_SPCR_BITS;
309 			reg_spcr_val |= (PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD);
310 
311 			iowrite32(reg_spcr_val, (io_remap_addr + PCH_SPCR));
312 		}
313 
314 		/* update counts */
315 		data->tx_index = tx_index;
316 		data->rx_index = rx_index;
317 
318 		/* if transfer complete interrupt */
319 		if (reg_spsr_val & SPSR_FI_BIT) {
320 			if ((tx_index == bpw_len) && (rx_index == tx_index)) {
321 				/* disable interrupts */
322 				pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
323 						   PCH_ALL);
324 
325 				/* transfer is completed;
326 				   inform pch_spi_process_messages */
327 				data->transfer_complete = true;
328 				data->transfer_active = false;
329 				wake_up(&data->wait);
330 			} else {
331 				dev_vdbg(&data->master->dev,
332 					"%s : Transfer is not completed",
333 					__func__);
334 			}
335 		}
336 	}
337 }
338 
339 /**
340  * pch_spi_handler() - Interrupt handler
341  * @irq:	The interrupt number.
342  * @dev_id:	Pointer to struct pch_spi_board_data.
343  */
344 static irqreturn_t pch_spi_handler(int irq, void *dev_id)
345 {
346 	u32 reg_spsr_val;
347 	void __iomem *spsr;
348 	void __iomem *io_remap_addr;
349 	irqreturn_t ret = IRQ_NONE;
350 	struct pch_spi_data *data = dev_id;
351 	struct pch_spi_board_data *board_dat = data->board_dat;
352 
353 	if (board_dat->suspend_sts) {
354 		dev_dbg(&board_dat->pdev->dev,
355 			"%s returning due to suspend\n", __func__);
356 		return IRQ_NONE;
357 	}
358 
359 	io_remap_addr = data->io_remap_addr;
360 	spsr = io_remap_addr + PCH_SPSR;
361 
362 	reg_spsr_val = ioread32(spsr);
363 
364 	if (reg_spsr_val & SPSR_ORF_BIT) {
365 		dev_err(&board_dat->pdev->dev, "%s Over run error\n", __func__);
366 		if (data->current_msg->complete) {
367 			data->transfer_complete = true;
368 			data->current_msg->status = -EIO;
369 			data->current_msg->complete(data->current_msg->context);
370 			data->bcurrent_msg_processing = false;
371 			data->current_msg = NULL;
372 			data->cur_trans = NULL;
373 		}
374 	}
375 
376 	if (data->use_dma)
377 		return IRQ_NONE;
378 
379 	/* Check if the interrupt is for SPI device */
380 	if (reg_spsr_val & (SPSR_FI_BIT | SPSR_RFI_BIT)) {
381 		pch_spi_handler_sub(data, reg_spsr_val, io_remap_addr);
382 		ret = IRQ_HANDLED;
383 	}
384 
385 	dev_dbg(&board_dat->pdev->dev, "%s EXIT return value=%d\n",
386 		__func__, ret);
387 
388 	return ret;
389 }
390 
391 /**
392  * pch_spi_set_baud_rate() - Sets SPBR field in SPBRR
393  * @master:	Pointer to struct spi_master.
394  * @speed_hz:	Baud rate.
395  */
396 static void pch_spi_set_baud_rate(struct spi_master *master, u32 speed_hz)
397 {
398 	u32 n_spbr = PCH_CLOCK_HZ / (speed_hz * 2);
399 
400 	/* if baud rate is less than we can support limit it */
401 	if (n_spbr > PCH_MAX_SPBR)
402 		n_spbr = PCH_MAX_SPBR;
403 
404 	pch_spi_setclr_reg(master, PCH_SPBRR, n_spbr, MASK_SPBRR_SPBR_BITS);
405 }
406 
407 /**
408  * pch_spi_set_bits_per_word() - Sets SIZE field in SPBRR
409  * @master:		Pointer to struct spi_master.
410  * @bits_per_word:	Bits per word for SPI transfer.
411  */
412 static void pch_spi_set_bits_per_word(struct spi_master *master,
413 				      u8 bits_per_word)
414 {
415 	if (bits_per_word == 8)
416 		pch_spi_setclr_reg(master, PCH_SPBRR, 0, SPBRR_SIZE_BIT);
417 	else
418 		pch_spi_setclr_reg(master, PCH_SPBRR, SPBRR_SIZE_BIT, 0);
419 }
420 
421 /**
422  * pch_spi_setup_transfer() - Configures the PCH SPI hardware for transfer
423  * @spi:	Pointer to struct spi_device.
424  */
425 static void pch_spi_setup_transfer(struct spi_device *spi)
426 {
427 	u32 flags = 0;
428 
429 	dev_dbg(&spi->dev, "%s SPBRR content =%x setting baud rate=%d\n",
430 		__func__, pch_spi_readreg(spi->master, PCH_SPBRR),
431 		spi->max_speed_hz);
432 	pch_spi_set_baud_rate(spi->master, spi->max_speed_hz);
433 
434 	/* set bits per word */
435 	pch_spi_set_bits_per_word(spi->master, spi->bits_per_word);
436 
437 	if (!(spi->mode & SPI_LSB_FIRST))
438 		flags |= SPCR_LSBF_BIT;
439 	if (spi->mode & SPI_CPOL)
440 		flags |= SPCR_CPOL_BIT;
441 	if (spi->mode & SPI_CPHA)
442 		flags |= SPCR_CPHA_BIT;
443 	pch_spi_setclr_reg(spi->master, PCH_SPCR, flags,
444 			   (SPCR_LSBF_BIT | SPCR_CPOL_BIT | SPCR_CPHA_BIT));
445 
446 	/* Clear the FIFO by toggling  FICLR to 1 and back to 0 */
447 	pch_spi_clear_fifo(spi->master);
448 }
449 
450 /**
451  * pch_spi_reset() - Clears SPI registers
452  * @master:	Pointer to struct spi_master.
453  */
454 static void pch_spi_reset(struct spi_master *master)
455 {
456 	/* write 1 to reset SPI */
457 	pch_spi_writereg(master, PCH_SRST, 0x1);
458 
459 	/* clear reset */
460 	pch_spi_writereg(master, PCH_SRST, 0x0);
461 }
462 
463 static int pch_spi_transfer(struct spi_device *pspi, struct spi_message *pmsg)
464 {
465 
466 	struct spi_transfer *transfer;
467 	struct pch_spi_data *data = spi_master_get_devdata(pspi->master);
468 	int retval;
469 	unsigned long flags;
470 
471 	spin_lock_irqsave(&data->lock, flags);
472 	/* validate Tx/Rx buffers and Transfer length */
473 	list_for_each_entry(transfer, &pmsg->transfers, transfer_list) {
474 		if (!transfer->tx_buf && !transfer->rx_buf) {
475 			dev_err(&pspi->dev,
476 				"%s Tx and Rx buffer NULL\n", __func__);
477 			retval = -EINVAL;
478 			goto err_return_spinlock;
479 		}
480 
481 		if (!transfer->len) {
482 			dev_err(&pspi->dev, "%s Transfer length invalid\n",
483 				__func__);
484 			retval = -EINVAL;
485 			goto err_return_spinlock;
486 		}
487 
488 		dev_dbg(&pspi->dev,
489 			"%s Tx/Rx buffer valid. Transfer length valid\n",
490 			__func__);
491 	}
492 	spin_unlock_irqrestore(&data->lock, flags);
493 
494 	/* We won't process any messages if we have been asked to terminate */
495 	if (data->status == STATUS_EXITING) {
496 		dev_err(&pspi->dev, "%s status = STATUS_EXITING.\n", __func__);
497 		retval = -ESHUTDOWN;
498 		goto err_out;
499 	}
500 
501 	/* If suspended ,return -EINVAL */
502 	if (data->board_dat->suspend_sts) {
503 		dev_err(&pspi->dev, "%s suspend; returning EINVAL\n", __func__);
504 		retval = -EINVAL;
505 		goto err_out;
506 	}
507 
508 	/* set status of message */
509 	pmsg->actual_length = 0;
510 	dev_dbg(&pspi->dev, "%s - pmsg->status =%d\n", __func__, pmsg->status);
511 
512 	pmsg->status = -EINPROGRESS;
513 	spin_lock_irqsave(&data->lock, flags);
514 	/* add message to queue */
515 	list_add_tail(&pmsg->queue, &data->queue);
516 	spin_unlock_irqrestore(&data->lock, flags);
517 
518 	dev_dbg(&pspi->dev, "%s - Invoked list_add_tail\n", __func__);
519 
520 	/* schedule work queue to run */
521 	queue_work(data->wk, &data->work);
522 	dev_dbg(&pspi->dev, "%s - Invoked queue work\n", __func__);
523 
524 	retval = 0;
525 
526 err_out:
527 	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
528 	return retval;
529 err_return_spinlock:
530 	dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
531 	spin_unlock_irqrestore(&data->lock, flags);
532 	return retval;
533 }
534 
535 static inline void pch_spi_select_chip(struct pch_spi_data *data,
536 				       struct spi_device *pspi)
537 {
538 	if (data->current_chip != NULL) {
539 		if (pspi->chip_select != data->n_curnt_chip) {
540 			dev_dbg(&pspi->dev, "%s : different slave\n", __func__);
541 			data->current_chip = NULL;
542 		}
543 	}
544 
545 	data->current_chip = pspi;
546 
547 	data->n_curnt_chip = data->current_chip->chip_select;
548 
549 	dev_dbg(&pspi->dev, "%s :Invoking pch_spi_setup_transfer\n", __func__);
550 	pch_spi_setup_transfer(pspi);
551 }
552 
553 static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw)
554 {
555 	int size;
556 	u32 n_writes;
557 	int j;
558 	struct spi_message *pmsg, *tmp;
559 	const u8 *tx_buf;
560 	const u16 *tx_sbuf;
561 
562 	/* set baud rate if needed */
563 	if (data->cur_trans->speed_hz) {
564 		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
565 		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
566 	}
567 
568 	/* set bits per word if needed */
569 	if (data->cur_trans->bits_per_word &&
570 	    (data->current_msg->spi->bits_per_word != data->cur_trans->bits_per_word)) {
571 		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
572 		pch_spi_set_bits_per_word(data->master,
573 					  data->cur_trans->bits_per_word);
574 		*bpw = data->cur_trans->bits_per_word;
575 	} else {
576 		*bpw = data->current_msg->spi->bits_per_word;
577 	}
578 
579 	/* reset Tx/Rx index */
580 	data->tx_index = 0;
581 	data->rx_index = 0;
582 
583 	data->bpw_len = data->cur_trans->len / (*bpw / 8);
584 
585 	/* find alloc size */
586 	size = data->cur_trans->len * sizeof(*data->pkt_tx_buff);
587 
588 	/* allocate memory for pkt_tx_buff & pkt_rx_buffer */
589 	data->pkt_tx_buff = kzalloc(size, GFP_KERNEL);
590 	if (data->pkt_tx_buff != NULL) {
591 		data->pkt_rx_buff = kzalloc(size, GFP_KERNEL);
592 		if (!data->pkt_rx_buff)
593 			kfree(data->pkt_tx_buff);
594 	}
595 
596 	if (!data->pkt_rx_buff) {
597 		/* flush queue and set status of all transfers to -ENOMEM */
598 		dev_err(&data->master->dev, "%s :kzalloc failed\n", __func__);
599 		list_for_each_entry_safe(pmsg, tmp, data->queue.next, queue) {
600 			pmsg->status = -ENOMEM;
601 
602 			if (pmsg->complete)
603 				pmsg->complete(pmsg->context);
604 
605 			/* delete from queue */
606 			list_del_init(&pmsg->queue);
607 		}
608 		return;
609 	}
610 
611 	/* copy Tx Data */
612 	if (data->cur_trans->tx_buf != NULL) {
613 		if (*bpw == 8) {
614 			tx_buf = data->cur_trans->tx_buf;
615 			for (j = 0; j < data->bpw_len; j++)
616 				data->pkt_tx_buff[j] = *tx_buf++;
617 		} else {
618 			tx_sbuf = data->cur_trans->tx_buf;
619 			for (j = 0; j < data->bpw_len; j++)
620 				data->pkt_tx_buff[j] = *tx_sbuf++;
621 		}
622 	}
623 
624 	/* if len greater than PCH_MAX_FIFO_DEPTH, write 16,else len bytes */
625 	n_writes = data->bpw_len;
626 	if (n_writes > PCH_MAX_FIFO_DEPTH)
627 		n_writes = PCH_MAX_FIFO_DEPTH;
628 
629 	dev_dbg(&data->master->dev, "\n%s:Pulling down SSN low - writing "
630 		"0x2 to SSNXCR\n", __func__);
631 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
632 
633 	for (j = 0; j < n_writes; j++)
634 		pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
635 
636 	/* update tx_index */
637 	data->tx_index = j;
638 
639 	/* reset transfer complete flag */
640 	data->transfer_complete = false;
641 	data->transfer_active = true;
642 }
643 
644 static void pch_spi_nomore_transfer(struct pch_spi_data *data)
645 {
646 	struct spi_message *pmsg, *tmp;
647 	dev_dbg(&data->master->dev, "%s called\n", __func__);
648 	/* Invoke complete callback
649 	 * [To the spi core..indicating end of transfer] */
650 	data->current_msg->status = 0;
651 
652 	if (data->current_msg->complete) {
653 		dev_dbg(&data->master->dev,
654 			"%s:Invoking callback of SPI core\n", __func__);
655 		data->current_msg->complete(data->current_msg->context);
656 	}
657 
658 	/* update status in global variable */
659 	data->bcurrent_msg_processing = false;
660 
661 	dev_dbg(&data->master->dev,
662 		"%s:data->bcurrent_msg_processing = false\n", __func__);
663 
664 	data->current_msg = NULL;
665 	data->cur_trans = NULL;
666 
667 	/* check if we have items in list and not suspending
668 	 * return 1 if list empty */
669 	if ((list_empty(&data->queue) == 0) &&
670 	    (!data->board_dat->suspend_sts) &&
671 	    (data->status != STATUS_EXITING)) {
672 		/* We have some more work to do (either there is more tranint
673 		 * bpw;sfer requests in the current message or there are
674 		 *more messages)
675 		 */
676 		dev_dbg(&data->master->dev, "%s:Invoke queue_work\n", __func__);
677 		queue_work(data->wk, &data->work);
678 	} else if (data->board_dat->suspend_sts ||
679 		   data->status == STATUS_EXITING) {
680 		dev_dbg(&data->master->dev,
681 			"%s suspend/remove initiated, flushing queue\n",
682 			__func__);
683 		list_for_each_entry_safe(pmsg, tmp, data->queue.next, queue) {
684 			pmsg->status = -EIO;
685 
686 			if (pmsg->complete)
687 				pmsg->complete(pmsg->context);
688 
689 			/* delete from queue */
690 			list_del_init(&pmsg->queue);
691 		}
692 	}
693 }
694 
695 static void pch_spi_set_ir(struct pch_spi_data *data)
696 {
697 	/* enable interrupts, set threshold, enable SPI */
698 	if ((data->bpw_len) > PCH_MAX_FIFO_DEPTH)
699 		/* set receive threshold to PCH_RX_THOLD */
700 		pch_spi_setclr_reg(data->master, PCH_SPCR,
701 				   PCH_RX_THOLD << SPCR_RFIC_FIELD |
702 				   SPCR_FIE_BIT | SPCR_RFIE_BIT |
703 				   SPCR_ORIE_BIT | SPCR_SPE_BIT,
704 				   MASK_RFIC_SPCR_BITS | PCH_ALL);
705 	else
706 		/* set receive threshold to maximum */
707 		pch_spi_setclr_reg(data->master, PCH_SPCR,
708 				   PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD |
709 				   SPCR_FIE_BIT | SPCR_ORIE_BIT |
710 				   SPCR_SPE_BIT,
711 				   MASK_RFIC_SPCR_BITS | PCH_ALL);
712 
713 	/* Wait until the transfer completes; go to sleep after
714 				 initiating the transfer. */
715 	dev_dbg(&data->master->dev,
716 		"%s:waiting for transfer to get over\n", __func__);
717 
718 	wait_event_interruptible(data->wait, data->transfer_complete);
719 
720 	/* clear all interrupts */
721 	pch_spi_writereg(data->master, PCH_SPSR,
722 			 pch_spi_readreg(data->master, PCH_SPSR));
723 	/* Disable interrupts and SPI transfer */
724 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL | SPCR_SPE_BIT);
725 	/* clear FIFO */
726 	pch_spi_clear_fifo(data->master);
727 }
728 
729 static void pch_spi_copy_rx_data(struct pch_spi_data *data, int bpw)
730 {
731 	int j;
732 	u8 *rx_buf;
733 	u16 *rx_sbuf;
734 
735 	/* copy Rx Data */
736 	if (!data->cur_trans->rx_buf)
737 		return;
738 
739 	if (bpw == 8) {
740 		rx_buf = data->cur_trans->rx_buf;
741 		for (j = 0; j < data->bpw_len; j++)
742 			*rx_buf++ = data->pkt_rx_buff[j] & 0xFF;
743 	} else {
744 		rx_sbuf = data->cur_trans->rx_buf;
745 		for (j = 0; j < data->bpw_len; j++)
746 			*rx_sbuf++ = data->pkt_rx_buff[j];
747 	}
748 }
749 
750 static void pch_spi_copy_rx_data_for_dma(struct pch_spi_data *data, int bpw)
751 {
752 	int j;
753 	u8 *rx_buf;
754 	u16 *rx_sbuf;
755 	const u8 *rx_dma_buf;
756 	const u16 *rx_dma_sbuf;
757 
758 	/* copy Rx Data */
759 	if (!data->cur_trans->rx_buf)
760 		return;
761 
762 	if (bpw == 8) {
763 		rx_buf = data->cur_trans->rx_buf;
764 		rx_dma_buf = data->dma.rx_buf_virt;
765 		for (j = 0; j < data->bpw_len; j++)
766 			*rx_buf++ = *rx_dma_buf++ & 0xFF;
767 		data->cur_trans->rx_buf = rx_buf;
768 	} else {
769 		rx_sbuf = data->cur_trans->rx_buf;
770 		rx_dma_sbuf = data->dma.rx_buf_virt;
771 		for (j = 0; j < data->bpw_len; j++)
772 			*rx_sbuf++ = *rx_dma_sbuf++;
773 		data->cur_trans->rx_buf = rx_sbuf;
774 	}
775 }
776 
777 static int pch_spi_start_transfer(struct pch_spi_data *data)
778 {
779 	struct pch_spi_dma_ctrl *dma;
780 	unsigned long flags;
781 	int rtn;
782 
783 	dma = &data->dma;
784 
785 	spin_lock_irqsave(&data->lock, flags);
786 
787 	/* disable interrupts, SPI set enable */
788 	pch_spi_setclr_reg(data->master, PCH_SPCR, SPCR_SPE_BIT, PCH_ALL);
789 
790 	spin_unlock_irqrestore(&data->lock, flags);
791 
792 	/* Wait until the transfer completes; go to sleep after
793 				 initiating the transfer. */
794 	dev_dbg(&data->master->dev,
795 		"%s:waiting for transfer to get over\n", __func__);
796 	rtn = wait_event_interruptible_timeout(data->wait,
797 					       data->transfer_complete,
798 					       msecs_to_jiffies(2 * HZ));
799 	if (!rtn)
800 		dev_err(&data->master->dev,
801 			"%s wait-event timeout\n", __func__);
802 
803 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
804 			    DMA_FROM_DEVICE);
805 
806 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_tx_p, dma->nent,
807 			    DMA_FROM_DEVICE);
808 	memset(data->dma.tx_buf_virt, 0, PAGE_SIZE);
809 
810 	async_tx_ack(dma->desc_rx);
811 	async_tx_ack(dma->desc_tx);
812 	kfree(dma->sg_tx_p);
813 	kfree(dma->sg_rx_p);
814 
815 	spin_lock_irqsave(&data->lock, flags);
816 
817 	/* clear fifo threshold, disable interrupts, disable SPI transfer */
818 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
819 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS | PCH_ALL |
820 			   SPCR_SPE_BIT);
821 	/* clear all interrupts */
822 	pch_spi_writereg(data->master, PCH_SPSR,
823 			 pch_spi_readreg(data->master, PCH_SPSR));
824 	/* clear FIFO */
825 	pch_spi_clear_fifo(data->master);
826 
827 	spin_unlock_irqrestore(&data->lock, flags);
828 
829 	return rtn;
830 }
831 
832 static void pch_dma_rx_complete(void *arg)
833 {
834 	struct pch_spi_data *data = arg;
835 
836 	/* transfer is completed;inform pch_spi_process_messages_dma */
837 	data->transfer_complete = true;
838 	wake_up_interruptible(&data->wait);
839 }
840 
841 static bool pch_spi_filter(struct dma_chan *chan, void *slave)
842 {
843 	struct pch_dma_slave *param = slave;
844 
845 	if ((chan->chan_id == param->chan_id) &&
846 	    (param->dma_dev == chan->device->dev)) {
847 		chan->private = param;
848 		return true;
849 	} else {
850 		return false;
851 	}
852 }
853 
854 static void pch_spi_request_dma(struct pch_spi_data *data, int bpw)
855 {
856 	dma_cap_mask_t mask;
857 	struct dma_chan *chan;
858 	struct pci_dev *dma_dev;
859 	struct pch_dma_slave *param;
860 	struct pch_spi_dma_ctrl *dma;
861 	unsigned int width;
862 
863 	if (bpw == 8)
864 		width = PCH_DMA_WIDTH_1_BYTE;
865 	else
866 		width = PCH_DMA_WIDTH_2_BYTES;
867 
868 	dma = &data->dma;
869 	dma_cap_zero(mask);
870 	dma_cap_set(DMA_SLAVE, mask);
871 
872 	/* Get DMA's dev information */
873 	dma_dev = pci_get_slot(data->board_dat->pdev->bus,
874 			PCI_DEVFN(PCI_SLOT(data->board_dat->pdev->devfn), 0));
875 
876 	/* Set Tx DMA */
877 	param = &dma->param_tx;
878 	param->dma_dev = &dma_dev->dev;
879 	param->chan_id = data->ch * 2; /* Tx = 0, 2 */;
880 	param->tx_reg = data->io_base_addr + PCH_SPDWR;
881 	param->width = width;
882 	chan = dma_request_channel(mask, pch_spi_filter, param);
883 	if (!chan) {
884 		dev_err(&data->master->dev,
885 			"ERROR: dma_request_channel FAILS(Tx)\n");
886 		data->use_dma = 0;
887 		return;
888 	}
889 	dma->chan_tx = chan;
890 
891 	/* Set Rx DMA */
892 	param = &dma->param_rx;
893 	param->dma_dev = &dma_dev->dev;
894 	param->chan_id = data->ch * 2 + 1; /* Rx = Tx + 1 */;
895 	param->rx_reg = data->io_base_addr + PCH_SPDRR;
896 	param->width = width;
897 	chan = dma_request_channel(mask, pch_spi_filter, param);
898 	if (!chan) {
899 		dev_err(&data->master->dev,
900 			"ERROR: dma_request_channel FAILS(Rx)\n");
901 		dma_release_channel(dma->chan_tx);
902 		dma->chan_tx = NULL;
903 		data->use_dma = 0;
904 		return;
905 	}
906 	dma->chan_rx = chan;
907 }
908 
909 static void pch_spi_release_dma(struct pch_spi_data *data)
910 {
911 	struct pch_spi_dma_ctrl *dma;
912 
913 	dma = &data->dma;
914 	if (dma->chan_tx) {
915 		dma_release_channel(dma->chan_tx);
916 		dma->chan_tx = NULL;
917 	}
918 	if (dma->chan_rx) {
919 		dma_release_channel(dma->chan_rx);
920 		dma->chan_rx = NULL;
921 	}
922 	return;
923 }
924 
925 static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
926 {
927 	const u8 *tx_buf;
928 	const u16 *tx_sbuf;
929 	u8 *tx_dma_buf;
930 	u16 *tx_dma_sbuf;
931 	struct scatterlist *sg;
932 	struct dma_async_tx_descriptor *desc_tx;
933 	struct dma_async_tx_descriptor *desc_rx;
934 	int num;
935 	int i;
936 	int size;
937 	int rem;
938 	int head;
939 	unsigned long flags;
940 	struct pch_spi_dma_ctrl *dma;
941 
942 	dma = &data->dma;
943 
944 	/* set baud rate if needed */
945 	if (data->cur_trans->speed_hz) {
946 		dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
947 		spin_lock_irqsave(&data->lock, flags);
948 		pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
949 		spin_unlock_irqrestore(&data->lock, flags);
950 	}
951 
952 	/* set bits per word if needed */
953 	if (data->cur_trans->bits_per_word &&
954 	    (data->current_msg->spi->bits_per_word !=
955 	     data->cur_trans->bits_per_word)) {
956 		dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
957 		spin_lock_irqsave(&data->lock, flags);
958 		pch_spi_set_bits_per_word(data->master,
959 					  data->cur_trans->bits_per_word);
960 		spin_unlock_irqrestore(&data->lock, flags);
961 		*bpw = data->cur_trans->bits_per_word;
962 	} else {
963 		*bpw = data->current_msg->spi->bits_per_word;
964 	}
965 	data->bpw_len = data->cur_trans->len / (*bpw / 8);
966 
967 	if (data->bpw_len > PCH_BUF_SIZE) {
968 		data->bpw_len = PCH_BUF_SIZE;
969 		data->cur_trans->len -= PCH_BUF_SIZE;
970 	}
971 
972 	/* copy Tx Data */
973 	if (data->cur_trans->tx_buf != NULL) {
974 		if (*bpw == 8) {
975 			tx_buf = data->cur_trans->tx_buf;
976 			tx_dma_buf = dma->tx_buf_virt;
977 			for (i = 0; i < data->bpw_len; i++)
978 				*tx_dma_buf++ = *tx_buf++;
979 		} else {
980 			tx_sbuf = data->cur_trans->tx_buf;
981 			tx_dma_sbuf = dma->tx_buf_virt;
982 			for (i = 0; i < data->bpw_len; i++)
983 				*tx_dma_sbuf++ = *tx_sbuf++;
984 		}
985 	}
986 
987 	/* Calculate Rx parameter for DMA transmitting */
988 	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
989 		if (data->bpw_len % PCH_DMA_TRANS_SIZE) {
990 			num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
991 			rem = data->bpw_len % PCH_DMA_TRANS_SIZE;
992 		} else {
993 			num = data->bpw_len / PCH_DMA_TRANS_SIZE;
994 			rem = PCH_DMA_TRANS_SIZE;
995 		}
996 		size = PCH_DMA_TRANS_SIZE;
997 	} else {
998 		num = 1;
999 		size = data->bpw_len;
1000 		rem = data->bpw_len;
1001 	}
1002 	dev_dbg(&data->master->dev, "%s num=%d size=%d rem=%d\n",
1003 		__func__, num, size, rem);
1004 	spin_lock_irqsave(&data->lock, flags);
1005 
1006 	/* set receive fifo threshold and transmit fifo threshold */
1007 	pch_spi_setclr_reg(data->master, PCH_SPCR,
1008 			   ((size - 1) << SPCR_RFIC_FIELD) |
1009 			   (PCH_TX_THOLD << SPCR_TFIC_FIELD),
1010 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS);
1011 
1012 	spin_unlock_irqrestore(&data->lock, flags);
1013 
1014 	/* RX */
1015 	dma->sg_rx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
1016 	sg_init_table(dma->sg_rx_p, num); /* Initialize SG table */
1017 	/* offset, length setting */
1018 	sg = dma->sg_rx_p;
1019 	for (i = 0; i < num; i++, sg++) {
1020 		if (i == (num - 2)) {
1021 			sg->offset = size * i;
1022 			sg->offset = sg->offset * (*bpw / 8);
1023 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), rem,
1024 				    sg->offset);
1025 			sg_dma_len(sg) = rem;
1026 		} else if (i == (num - 1)) {
1027 			sg->offset = size * (i - 1) + rem;
1028 			sg->offset = sg->offset * (*bpw / 8);
1029 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
1030 				    sg->offset);
1031 			sg_dma_len(sg) = size;
1032 		} else {
1033 			sg->offset = size * i;
1034 			sg->offset = sg->offset * (*bpw / 8);
1035 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
1036 				    sg->offset);
1037 			sg_dma_len(sg) = size;
1038 		}
1039 		sg_dma_address(sg) = dma->rx_buf_dma + sg->offset;
1040 	}
1041 	sg = dma->sg_rx_p;
1042 	desc_rx = dmaengine_prep_slave_sg(dma->chan_rx, sg,
1043 					num, DMA_DEV_TO_MEM,
1044 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1045 	if (!desc_rx) {
1046 		dev_err(&data->master->dev,
1047 			"%s:dmaengine_prep_slave_sg Failed\n", __func__);
1048 		return;
1049 	}
1050 	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_FROM_DEVICE);
1051 	desc_rx->callback = pch_dma_rx_complete;
1052 	desc_rx->callback_param = data;
1053 	dma->nent = num;
1054 	dma->desc_rx = desc_rx;
1055 
1056 	/* Calculate Tx parameter for DMA transmitting */
1057 	if (data->bpw_len > PCH_MAX_FIFO_DEPTH) {
1058 		head = PCH_MAX_FIFO_DEPTH - PCH_DMA_TRANS_SIZE;
1059 		if (data->bpw_len % PCH_DMA_TRANS_SIZE > 4) {
1060 			num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
1061 			rem = data->bpw_len % PCH_DMA_TRANS_SIZE - head;
1062 		} else {
1063 			num = data->bpw_len / PCH_DMA_TRANS_SIZE;
1064 			rem = data->bpw_len % PCH_DMA_TRANS_SIZE +
1065 			      PCH_DMA_TRANS_SIZE - head;
1066 		}
1067 		size = PCH_DMA_TRANS_SIZE;
1068 	} else {
1069 		num = 1;
1070 		size = data->bpw_len;
1071 		rem = data->bpw_len;
1072 		head = 0;
1073 	}
1074 
1075 	dma->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
1076 	sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */
1077 	/* offset, length setting */
1078 	sg = dma->sg_tx_p;
1079 	for (i = 0; i < num; i++, sg++) {
1080 		if (i == 0) {
1081 			sg->offset = 0;
1082 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size + head,
1083 				    sg->offset);
1084 			sg_dma_len(sg) = size + head;
1085 		} else if (i == (num - 1)) {
1086 			sg->offset = head + size * i;
1087 			sg->offset = sg->offset * (*bpw / 8);
1088 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), rem,
1089 				    sg->offset);
1090 			sg_dma_len(sg) = rem;
1091 		} else {
1092 			sg->offset = head + size * i;
1093 			sg->offset = sg->offset * (*bpw / 8);
1094 			sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size,
1095 				    sg->offset);
1096 			sg_dma_len(sg) = size;
1097 		}
1098 		sg_dma_address(sg) = dma->tx_buf_dma + sg->offset;
1099 	}
1100 	sg = dma->sg_tx_p;
1101 	desc_tx = dmaengine_prep_slave_sg(dma->chan_tx,
1102 					sg, num, DMA_MEM_TO_DEV,
1103 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1104 	if (!desc_tx) {
1105 		dev_err(&data->master->dev,
1106 			"%s:dmaengine_prep_slave_sg Failed\n", __func__);
1107 		return;
1108 	}
1109 	dma_sync_sg_for_device(&data->master->dev, sg, num, DMA_TO_DEVICE);
1110 	desc_tx->callback = NULL;
1111 	desc_tx->callback_param = data;
1112 	dma->nent = num;
1113 	dma->desc_tx = desc_tx;
1114 
1115 	dev_dbg(&data->master->dev, "%s:Pulling down SSN low - writing 0x2 to SSNXCR\n", __func__);
1116 
1117 	spin_lock_irqsave(&data->lock, flags);
1118 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
1119 	desc_rx->tx_submit(desc_rx);
1120 	desc_tx->tx_submit(desc_tx);
1121 	spin_unlock_irqrestore(&data->lock, flags);
1122 
1123 	/* reset transfer complete flag */
1124 	data->transfer_complete = false;
1125 }
1126 
1127 static void pch_spi_process_messages(struct work_struct *pwork)
1128 {
1129 	struct spi_message *pmsg, *tmp;
1130 	struct pch_spi_data *data;
1131 	int bpw;
1132 
1133 	data = container_of(pwork, struct pch_spi_data, work);
1134 	dev_dbg(&data->master->dev, "%s data initialized\n", __func__);
1135 
1136 	spin_lock(&data->lock);
1137 	/* check if suspend has been initiated;if yes flush queue */
1138 	if (data->board_dat->suspend_sts || (data->status == STATUS_EXITING)) {
1139 		dev_dbg(&data->master->dev,
1140 			"%s suspend/remove initiated, flushing queue\n", __func__);
1141 		list_for_each_entry_safe(pmsg, tmp, data->queue.next, queue) {
1142 			pmsg->status = -EIO;
1143 
1144 			if (pmsg->complete) {
1145 				spin_unlock(&data->lock);
1146 				pmsg->complete(pmsg->context);
1147 				spin_lock(&data->lock);
1148 			}
1149 
1150 			/* delete from queue */
1151 			list_del_init(&pmsg->queue);
1152 		}
1153 
1154 		spin_unlock(&data->lock);
1155 		return;
1156 	}
1157 
1158 	data->bcurrent_msg_processing = true;
1159 	dev_dbg(&data->master->dev,
1160 		"%s Set data->bcurrent_msg_processing= true\n", __func__);
1161 
1162 	/* Get the message from the queue and delete it from there. */
1163 	data->current_msg = list_entry(data->queue.next, struct spi_message,
1164 					queue);
1165 
1166 	list_del_init(&data->current_msg->queue);
1167 
1168 	data->current_msg->status = 0;
1169 
1170 	pch_spi_select_chip(data, data->current_msg->spi);
1171 
1172 	spin_unlock(&data->lock);
1173 
1174 	if (data->use_dma)
1175 		pch_spi_request_dma(data,
1176 				    data->current_msg->spi->bits_per_word);
1177 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
1178 	do {
1179 		int cnt;
1180 		/* If we are already processing a message get the next
1181 		transfer structure from the message otherwise retrieve
1182 		the 1st transfer request from the message. */
1183 		spin_lock(&data->lock);
1184 		if (data->cur_trans == NULL) {
1185 			data->cur_trans =
1186 				list_entry(data->current_msg->transfers.next,
1187 					   struct spi_transfer, transfer_list);
1188 			dev_dbg(&data->master->dev, "%s "
1189 				":Getting 1st transfer message\n", __func__);
1190 		} else {
1191 			data->cur_trans =
1192 				list_entry(data->cur_trans->transfer_list.next,
1193 					   struct spi_transfer, transfer_list);
1194 			dev_dbg(&data->master->dev, "%s "
1195 				":Getting next transfer message\n", __func__);
1196 		}
1197 		spin_unlock(&data->lock);
1198 
1199 		if (!data->cur_trans->len)
1200 			goto out;
1201 		cnt = (data->cur_trans->len - 1) / PCH_BUF_SIZE + 1;
1202 		data->save_total_len = data->cur_trans->len;
1203 		if (data->use_dma) {
1204 			int i;
1205 			char *save_rx_buf = data->cur_trans->rx_buf;
1206 			for (i = 0; i < cnt; i ++) {
1207 				pch_spi_handle_dma(data, &bpw);
1208 				if (!pch_spi_start_transfer(data)) {
1209 					data->transfer_complete = true;
1210 					data->current_msg->status = -EIO;
1211 					data->current_msg->complete
1212 						   (data->current_msg->context);
1213 					data->bcurrent_msg_processing = false;
1214 					data->current_msg = NULL;
1215 					data->cur_trans = NULL;
1216 					goto out;
1217 				}
1218 				pch_spi_copy_rx_data_for_dma(data, bpw);
1219 			}
1220 			data->cur_trans->rx_buf = save_rx_buf;
1221 		} else {
1222 			pch_spi_set_tx(data, &bpw);
1223 			pch_spi_set_ir(data);
1224 			pch_spi_copy_rx_data(data, bpw);
1225 			kfree(data->pkt_rx_buff);
1226 			data->pkt_rx_buff = NULL;
1227 			kfree(data->pkt_tx_buff);
1228 			data->pkt_tx_buff = NULL;
1229 		}
1230 		/* increment message count */
1231 		data->cur_trans->len = data->save_total_len;
1232 		data->current_msg->actual_length += data->cur_trans->len;
1233 
1234 		dev_dbg(&data->master->dev,
1235 			"%s:data->current_msg->actual_length=%d\n",
1236 			__func__, data->current_msg->actual_length);
1237 
1238 		/* check for delay */
1239 		if (data->cur_trans->delay_usecs) {
1240 			dev_dbg(&data->master->dev, "%s:"
1241 				"delay in usec=%d\n", __func__,
1242 				data->cur_trans->delay_usecs);
1243 			udelay(data->cur_trans->delay_usecs);
1244 		}
1245 
1246 		spin_lock(&data->lock);
1247 
1248 		/* No more transfer in this message. */
1249 		if ((data->cur_trans->transfer_list.next) ==
1250 		    &(data->current_msg->transfers)) {
1251 			pch_spi_nomore_transfer(data);
1252 		}
1253 
1254 		spin_unlock(&data->lock);
1255 
1256 	} while (data->cur_trans != NULL);
1257 
1258 out:
1259 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_HIGH);
1260 	if (data->use_dma)
1261 		pch_spi_release_dma(data);
1262 }
1263 
1264 static void pch_spi_free_resources(struct pch_spi_board_data *board_dat,
1265 				   struct pch_spi_data *data)
1266 {
1267 	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
1268 
1269 	/* free workqueue */
1270 	if (data->wk != NULL) {
1271 		destroy_workqueue(data->wk);
1272 		data->wk = NULL;
1273 		dev_dbg(&board_dat->pdev->dev,
1274 			"%s destroy_workqueue invoked successfully\n",
1275 			__func__);
1276 	}
1277 }
1278 
1279 static int pch_spi_get_resources(struct pch_spi_board_data *board_dat,
1280 				 struct pch_spi_data *data)
1281 {
1282 	int retval = 0;
1283 
1284 	dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
1285 
1286 	/* create workqueue */
1287 	data->wk = create_singlethread_workqueue(KBUILD_MODNAME);
1288 	if (!data->wk) {
1289 		dev_err(&board_dat->pdev->dev,
1290 			"%s create_singlet hread_workqueue failed\n", __func__);
1291 		retval = -EBUSY;
1292 		goto err_return;
1293 	}
1294 
1295 	/* reset PCH SPI h/w */
1296 	pch_spi_reset(data->master);
1297 	dev_dbg(&board_dat->pdev->dev,
1298 		"%s pch_spi_reset invoked successfully\n", __func__);
1299 
1300 	dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true\n", __func__);
1301 
1302 err_return:
1303 	if (retval != 0) {
1304 		dev_err(&board_dat->pdev->dev,
1305 			"%s FAIL:invoking pch_spi_free_resources\n", __func__);
1306 		pch_spi_free_resources(board_dat, data);
1307 	}
1308 
1309 	dev_dbg(&board_dat->pdev->dev, "%s Return=%d\n", __func__, retval);
1310 
1311 	return retval;
1312 }
1313 
1314 static void pch_free_dma_buf(struct pch_spi_board_data *board_dat,
1315 			     struct pch_spi_data *data)
1316 {
1317 	struct pch_spi_dma_ctrl *dma;
1318 
1319 	dma = &data->dma;
1320 	if (dma->tx_buf_dma)
1321 		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
1322 				  dma->tx_buf_virt, dma->tx_buf_dma);
1323 	if (dma->rx_buf_dma)
1324 		dma_free_coherent(&board_dat->pdev->dev, PCH_BUF_SIZE,
1325 				  dma->rx_buf_virt, dma->rx_buf_dma);
1326 	return;
1327 }
1328 
1329 static void pch_alloc_dma_buf(struct pch_spi_board_data *board_dat,
1330 			      struct pch_spi_data *data)
1331 {
1332 	struct pch_spi_dma_ctrl *dma;
1333 
1334 	dma = &data->dma;
1335 	/* Get Consistent memory for Tx DMA */
1336 	dma->tx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
1337 				PCH_BUF_SIZE, &dma->tx_buf_dma, GFP_KERNEL);
1338 	/* Get Consistent memory for Rx DMA */
1339 	dma->rx_buf_virt = dma_alloc_coherent(&board_dat->pdev->dev,
1340 				PCH_BUF_SIZE, &dma->rx_buf_dma, GFP_KERNEL);
1341 }
1342 
1343 static int pch_spi_pd_probe(struct platform_device *plat_dev)
1344 {
1345 	int ret;
1346 	struct spi_master *master;
1347 	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
1348 	struct pch_spi_data *data;
1349 
1350 	dev_dbg(&plat_dev->dev, "%s:debug\n", __func__);
1351 
1352 	master = spi_alloc_master(&board_dat->pdev->dev,
1353 				  sizeof(struct pch_spi_data));
1354 	if (!master) {
1355 		dev_err(&plat_dev->dev, "spi_alloc_master[%d] failed.\n",
1356 			plat_dev->id);
1357 		return -ENOMEM;
1358 	}
1359 
1360 	data = spi_master_get_devdata(master);
1361 	data->master = master;
1362 
1363 	platform_set_drvdata(plat_dev, data);
1364 
1365 	/* baseaddress + address offset) */
1366 	data->io_base_addr = pci_resource_start(board_dat->pdev, 1) +
1367 					 PCH_ADDRESS_SIZE * plat_dev->id;
1368 	data->io_remap_addr = pci_iomap(board_dat->pdev, 1, 0);
1369 	if (!data->io_remap_addr) {
1370 		dev_err(&plat_dev->dev, "%s pci_iomap failed\n", __func__);
1371 		ret = -ENOMEM;
1372 		goto err_pci_iomap;
1373 	}
1374 	data->io_remap_addr += PCH_ADDRESS_SIZE * plat_dev->id;
1375 
1376 	dev_dbg(&plat_dev->dev, "[ch%d] remap_addr=%p\n",
1377 		plat_dev->id, data->io_remap_addr);
1378 
1379 	/* initialize members of SPI master */
1380 	master->num_chipselect = PCH_MAX_CS;
1381 	master->transfer = pch_spi_transfer;
1382 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1383 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
1384 	master->max_speed_hz = PCH_MAX_BAUDRATE;
1385 
1386 	data->board_dat = board_dat;
1387 	data->plat_dev = plat_dev;
1388 	data->n_curnt_chip = 255;
1389 	data->status = STATUS_RUNNING;
1390 	data->ch = plat_dev->id;
1391 	data->use_dma = use_dma;
1392 
1393 	INIT_LIST_HEAD(&data->queue);
1394 	spin_lock_init(&data->lock);
1395 	INIT_WORK(&data->work, pch_spi_process_messages);
1396 	init_waitqueue_head(&data->wait);
1397 
1398 	ret = pch_spi_get_resources(board_dat, data);
1399 	if (ret) {
1400 		dev_err(&plat_dev->dev, "%s fail(retval=%d)\n", __func__, ret);
1401 		goto err_spi_get_resources;
1402 	}
1403 
1404 	ret = request_irq(board_dat->pdev->irq, pch_spi_handler,
1405 			  IRQF_SHARED, KBUILD_MODNAME, data);
1406 	if (ret) {
1407 		dev_err(&plat_dev->dev,
1408 			"%s request_irq failed\n", __func__);
1409 		goto err_request_irq;
1410 	}
1411 	data->irq_reg_sts = true;
1412 
1413 	pch_spi_set_master_mode(master);
1414 
1415 	if (use_dma) {
1416 		dev_info(&plat_dev->dev, "Use DMA for data transfers\n");
1417 		pch_alloc_dma_buf(board_dat, data);
1418 	}
1419 
1420 	ret = spi_register_master(master);
1421 	if (ret != 0) {
1422 		dev_err(&plat_dev->dev,
1423 			"%s spi_register_master FAILED\n", __func__);
1424 		goto err_spi_register_master;
1425 	}
1426 
1427 	return 0;
1428 
1429 err_spi_register_master:
1430 	pch_free_dma_buf(board_dat, data);
1431 	free_irq(board_dat->pdev->irq, data);
1432 err_request_irq:
1433 	pch_spi_free_resources(board_dat, data);
1434 err_spi_get_resources:
1435 	pci_iounmap(board_dat->pdev, data->io_remap_addr);
1436 err_pci_iomap:
1437 	spi_master_put(master);
1438 
1439 	return ret;
1440 }
1441 
1442 static int pch_spi_pd_remove(struct platform_device *plat_dev)
1443 {
1444 	struct pch_spi_board_data *board_dat = dev_get_platdata(&plat_dev->dev);
1445 	struct pch_spi_data *data = platform_get_drvdata(plat_dev);
1446 	int count;
1447 	unsigned long flags;
1448 
1449 	dev_dbg(&plat_dev->dev, "%s:[ch%d] irq=%d\n",
1450 		__func__, plat_dev->id, board_dat->pdev->irq);
1451 
1452 	if (use_dma)
1453 		pch_free_dma_buf(board_dat, data);
1454 
1455 	/* check for any pending messages; no action is taken if the queue
1456 	 * is still full; but at least we tried.  Unload anyway */
1457 	count = 500;
1458 	spin_lock_irqsave(&data->lock, flags);
1459 	data->status = STATUS_EXITING;
1460 	while ((list_empty(&data->queue) == 0) && --count) {
1461 		dev_dbg(&board_dat->pdev->dev, "%s :queue not empty\n",
1462 			__func__);
1463 		spin_unlock_irqrestore(&data->lock, flags);
1464 		msleep(PCH_SLEEP_TIME);
1465 		spin_lock_irqsave(&data->lock, flags);
1466 	}
1467 	spin_unlock_irqrestore(&data->lock, flags);
1468 
1469 	pch_spi_free_resources(board_dat, data);
1470 	/* disable interrupts & free IRQ */
1471 	if (data->irq_reg_sts) {
1472 		/* disable interrupts */
1473 		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
1474 		data->irq_reg_sts = false;
1475 		free_irq(board_dat->pdev->irq, data);
1476 	}
1477 
1478 	pci_iounmap(board_dat->pdev, data->io_remap_addr);
1479 	spi_unregister_master(data->master);
1480 
1481 	return 0;
1482 }
1483 #ifdef CONFIG_PM
1484 static int pch_spi_pd_suspend(struct platform_device *pd_dev,
1485 			      pm_message_t state)
1486 {
1487 	u8 count;
1488 	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
1489 	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
1490 
1491 	dev_dbg(&pd_dev->dev, "%s ENTRY\n", __func__);
1492 
1493 	if (!board_dat) {
1494 		dev_err(&pd_dev->dev,
1495 			"%s pci_get_drvdata returned NULL\n", __func__);
1496 		return -EFAULT;
1497 	}
1498 
1499 	/* check if the current message is processed:
1500 	   Only after thats done the transfer will be suspended */
1501 	count = 255;
1502 	while ((--count) > 0) {
1503 		if (!(data->bcurrent_msg_processing))
1504 			break;
1505 		msleep(PCH_SLEEP_TIME);
1506 	}
1507 
1508 	/* Free IRQ */
1509 	if (data->irq_reg_sts) {
1510 		/* disable all interrupts */
1511 		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
1512 		pch_spi_reset(data->master);
1513 		free_irq(board_dat->pdev->irq, data);
1514 
1515 		data->irq_reg_sts = false;
1516 		dev_dbg(&pd_dev->dev,
1517 			"%s free_irq invoked successfully.\n", __func__);
1518 	}
1519 
1520 	return 0;
1521 }
1522 
1523 static int pch_spi_pd_resume(struct platform_device *pd_dev)
1524 {
1525 	struct pch_spi_board_data *board_dat = dev_get_platdata(&pd_dev->dev);
1526 	struct pch_spi_data *data = platform_get_drvdata(pd_dev);
1527 	int retval;
1528 
1529 	if (!board_dat) {
1530 		dev_err(&pd_dev->dev,
1531 			"%s pci_get_drvdata returned NULL\n", __func__);
1532 		return -EFAULT;
1533 	}
1534 
1535 	if (!data->irq_reg_sts) {
1536 		/* register IRQ */
1537 		retval = request_irq(board_dat->pdev->irq, pch_spi_handler,
1538 				     IRQF_SHARED, KBUILD_MODNAME, data);
1539 		if (retval < 0) {
1540 			dev_err(&pd_dev->dev,
1541 				"%s request_irq failed\n", __func__);
1542 			return retval;
1543 		}
1544 
1545 		/* reset PCH SPI h/w */
1546 		pch_spi_reset(data->master);
1547 		pch_spi_set_master_mode(data->master);
1548 		data->irq_reg_sts = true;
1549 	}
1550 	return 0;
1551 }
1552 #else
1553 #define pch_spi_pd_suspend NULL
1554 #define pch_spi_pd_resume NULL
1555 #endif
1556 
1557 static struct platform_driver pch_spi_pd_driver = {
1558 	.driver = {
1559 		.name = "pch-spi",
1560 	},
1561 	.probe = pch_spi_pd_probe,
1562 	.remove = pch_spi_pd_remove,
1563 	.suspend = pch_spi_pd_suspend,
1564 	.resume = pch_spi_pd_resume
1565 };
1566 
1567 static int pch_spi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1568 {
1569 	struct pch_spi_board_data *board_dat;
1570 	struct platform_device *pd_dev = NULL;
1571 	int retval;
1572 	int i;
1573 	struct pch_pd_dev_save *pd_dev_save;
1574 
1575 	pd_dev_save = kzalloc(sizeof(struct pch_pd_dev_save), GFP_KERNEL);
1576 	if (!pd_dev_save)
1577 		return -ENOMEM;
1578 
1579 	board_dat = kzalloc(sizeof(struct pch_spi_board_data), GFP_KERNEL);
1580 	if (!board_dat) {
1581 		retval = -ENOMEM;
1582 		goto err_no_mem;
1583 	}
1584 
1585 	retval = pci_request_regions(pdev, KBUILD_MODNAME);
1586 	if (retval) {
1587 		dev_err(&pdev->dev, "%s request_region failed\n", __func__);
1588 		goto pci_request_regions;
1589 	}
1590 
1591 	board_dat->pdev = pdev;
1592 	board_dat->num = id->driver_data;
1593 	pd_dev_save->num = id->driver_data;
1594 	pd_dev_save->board_dat = board_dat;
1595 
1596 	retval = pci_enable_device(pdev);
1597 	if (retval) {
1598 		dev_err(&pdev->dev, "%s pci_enable_device failed\n", __func__);
1599 		goto pci_enable_device;
1600 	}
1601 
1602 	for (i = 0; i < board_dat->num; i++) {
1603 		pd_dev = platform_device_alloc("pch-spi", i);
1604 		if (!pd_dev) {
1605 			dev_err(&pdev->dev, "platform_device_alloc failed\n");
1606 			retval = -ENOMEM;
1607 			goto err_platform_device;
1608 		}
1609 		pd_dev_save->pd_save[i] = pd_dev;
1610 		pd_dev->dev.parent = &pdev->dev;
1611 
1612 		retval = platform_device_add_data(pd_dev, board_dat,
1613 						  sizeof(*board_dat));
1614 		if (retval) {
1615 			dev_err(&pdev->dev,
1616 				"platform_device_add_data failed\n");
1617 			platform_device_put(pd_dev);
1618 			goto err_platform_device;
1619 		}
1620 
1621 		retval = platform_device_add(pd_dev);
1622 		if (retval) {
1623 			dev_err(&pdev->dev, "platform_device_add failed\n");
1624 			platform_device_put(pd_dev);
1625 			goto err_platform_device;
1626 		}
1627 	}
1628 
1629 	pci_set_drvdata(pdev, pd_dev_save);
1630 
1631 	return 0;
1632 
1633 err_platform_device:
1634 	while (--i >= 0)
1635 		platform_device_unregister(pd_dev_save->pd_save[i]);
1636 	pci_disable_device(pdev);
1637 pci_enable_device:
1638 	pci_release_regions(pdev);
1639 pci_request_regions:
1640 	kfree(board_dat);
1641 err_no_mem:
1642 	kfree(pd_dev_save);
1643 
1644 	return retval;
1645 }
1646 
1647 static void pch_spi_remove(struct pci_dev *pdev)
1648 {
1649 	int i;
1650 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1651 
1652 	dev_dbg(&pdev->dev, "%s ENTRY:pdev=%p\n", __func__, pdev);
1653 
1654 	for (i = 0; i < pd_dev_save->num; i++)
1655 		platform_device_unregister(pd_dev_save->pd_save[i]);
1656 
1657 	pci_disable_device(pdev);
1658 	pci_release_regions(pdev);
1659 	kfree(pd_dev_save->board_dat);
1660 	kfree(pd_dev_save);
1661 }
1662 
1663 #ifdef CONFIG_PM
1664 static int pch_spi_suspend(struct pci_dev *pdev, pm_message_t state)
1665 {
1666 	int retval;
1667 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1668 
1669 	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
1670 
1671 	pd_dev_save->board_dat->suspend_sts = true;
1672 
1673 	/* save config space */
1674 	retval = pci_save_state(pdev);
1675 	if (retval == 0) {
1676 		pci_enable_wake(pdev, PCI_D3hot, 0);
1677 		pci_disable_device(pdev);
1678 		pci_set_power_state(pdev, PCI_D3hot);
1679 	} else {
1680 		dev_err(&pdev->dev, "%s pci_save_state failed\n", __func__);
1681 	}
1682 
1683 	return retval;
1684 }
1685 
1686 static int pch_spi_resume(struct pci_dev *pdev)
1687 {
1688 	int retval;
1689 	struct pch_pd_dev_save *pd_dev_save = pci_get_drvdata(pdev);
1690 	dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
1691 
1692 	pci_set_power_state(pdev, PCI_D0);
1693 	pci_restore_state(pdev);
1694 
1695 	retval = pci_enable_device(pdev);
1696 	if (retval < 0) {
1697 		dev_err(&pdev->dev,
1698 			"%s pci_enable_device failed\n", __func__);
1699 	} else {
1700 		pci_enable_wake(pdev, PCI_D3hot, 0);
1701 
1702 		/* set suspend status to false */
1703 		pd_dev_save->board_dat->suspend_sts = false;
1704 	}
1705 
1706 	return retval;
1707 }
1708 #else
1709 #define pch_spi_suspend NULL
1710 #define pch_spi_resume NULL
1711 
1712 #endif
1713 
1714 static struct pci_driver pch_spi_pcidev_driver = {
1715 	.name = "pch_spi",
1716 	.id_table = pch_spi_pcidev_id,
1717 	.probe = pch_spi_probe,
1718 	.remove = pch_spi_remove,
1719 	.suspend = pch_spi_suspend,
1720 	.resume = pch_spi_resume,
1721 };
1722 
1723 static int __init pch_spi_init(void)
1724 {
1725 	int ret;
1726 	ret = platform_driver_register(&pch_spi_pd_driver);
1727 	if (ret)
1728 		return ret;
1729 
1730 	ret = pci_register_driver(&pch_spi_pcidev_driver);
1731 	if (ret) {
1732 		platform_driver_unregister(&pch_spi_pd_driver);
1733 		return ret;
1734 	}
1735 
1736 	return 0;
1737 }
1738 module_init(pch_spi_init);
1739 
1740 static void __exit pch_spi_exit(void)
1741 {
1742 	pci_unregister_driver(&pch_spi_pcidev_driver);
1743 	platform_driver_unregister(&pch_spi_pd_driver);
1744 }
1745 module_exit(pch_spi_exit);
1746 
1747 module_param(use_dma, int, 0644);
1748 MODULE_PARM_DESC(use_dma,
1749 		 "to use DMA for data transfers pass 1 else 0; default 1");
1750 
1751 MODULE_LICENSE("GPL");
1752 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semiconductor ML7xxx IOH SPI Driver");
1753 MODULE_DEVICE_TABLE(pci, pch_spi_pcidev_id);
1754 
1755