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