xref: /openbmc/linux/drivers/spi/spi-pl022.c (revision d0b5e15f)
1 /*
2  * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
3  *
4  * Copyright (C) 2008-2012 ST-Ericsson AB
5  * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
6  *
7  * Author: Linus Walleij <linus.walleij@stericsson.com>
8  *
9  * Initial version inspired by:
10  *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
11  * Initial adoption to PL022 by:
12  *      Sachin Verma <sachin.verma@st.com>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24 
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/device.h>
28 #include <linux/ioport.h>
29 #include <linux/errno.h>
30 #include <linux/interrupt.h>
31 #include <linux/spi/spi.h>
32 #include <linux/delay.h>
33 #include <linux/clk.h>
34 #include <linux/err.h>
35 #include <linux/amba/bus.h>
36 #include <linux/amba/pl022.h>
37 #include <linux/io.h>
38 #include <linux/slab.h>
39 #include <linux/dmaengine.h>
40 #include <linux/dma-mapping.h>
41 #include <linux/scatterlist.h>
42 #include <linux/pm_runtime.h>
43 #include <linux/gpio.h>
44 #include <linux/of_gpio.h>
45 #include <linux/pinctrl/consumer.h>
46 
47 /*
48  * This macro is used to define some register default values.
49  * reg is masked with mask, the OR:ed with an (again masked)
50  * val shifted sb steps to the left.
51  */
52 #define SSP_WRITE_BITS(reg, val, mask, sb) \
53  ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
54 
55 /*
56  * This macro is also used to define some default values.
57  * It will just shift val by sb steps to the left and mask
58  * the result with mask.
59  */
60 #define GEN_MASK_BITS(val, mask, sb) \
61  (((val)<<(sb)) & (mask))
62 
63 #define DRIVE_TX		0
64 #define DO_NOT_DRIVE_TX		1
65 
66 #define DO_NOT_QUEUE_DMA	0
67 #define QUEUE_DMA		1
68 
69 #define RX_TRANSFER		1
70 #define TX_TRANSFER		2
71 
72 /*
73  * Macros to access SSP Registers with their offsets
74  */
75 #define SSP_CR0(r)	(r + 0x000)
76 #define SSP_CR1(r)	(r + 0x004)
77 #define SSP_DR(r)	(r + 0x008)
78 #define SSP_SR(r)	(r + 0x00C)
79 #define SSP_CPSR(r)	(r + 0x010)
80 #define SSP_IMSC(r)	(r + 0x014)
81 #define SSP_RIS(r)	(r + 0x018)
82 #define SSP_MIS(r)	(r + 0x01C)
83 #define SSP_ICR(r)	(r + 0x020)
84 #define SSP_DMACR(r)	(r + 0x024)
85 #define SSP_CSR(r)	(r + 0x030) /* vendor extension */
86 #define SSP_ITCR(r)	(r + 0x080)
87 #define SSP_ITIP(r)	(r + 0x084)
88 #define SSP_ITOP(r)	(r + 0x088)
89 #define SSP_TDR(r)	(r + 0x08C)
90 
91 #define SSP_PID0(r)	(r + 0xFE0)
92 #define SSP_PID1(r)	(r + 0xFE4)
93 #define SSP_PID2(r)	(r + 0xFE8)
94 #define SSP_PID3(r)	(r + 0xFEC)
95 
96 #define SSP_CID0(r)	(r + 0xFF0)
97 #define SSP_CID1(r)	(r + 0xFF4)
98 #define SSP_CID2(r)	(r + 0xFF8)
99 #define SSP_CID3(r)	(r + 0xFFC)
100 
101 /*
102  * SSP Control Register 0  - SSP_CR0
103  */
104 #define SSP_CR0_MASK_DSS	(0x0FUL << 0)
105 #define SSP_CR0_MASK_FRF	(0x3UL << 4)
106 #define SSP_CR0_MASK_SPO	(0x1UL << 6)
107 #define SSP_CR0_MASK_SPH	(0x1UL << 7)
108 #define SSP_CR0_MASK_SCR	(0xFFUL << 8)
109 
110 /*
111  * The ST version of this block moves som bits
112  * in SSP_CR0 and extends it to 32 bits
113  */
114 #define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
115 #define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
116 #define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
117 #define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
118 
119 /*
120  * SSP Control Register 0  - SSP_CR1
121  */
122 #define SSP_CR1_MASK_LBM	(0x1UL << 0)
123 #define SSP_CR1_MASK_SSE	(0x1UL << 1)
124 #define SSP_CR1_MASK_MS		(0x1UL << 2)
125 #define SSP_CR1_MASK_SOD	(0x1UL << 3)
126 
127 /*
128  * The ST version of this block adds some bits
129  * in SSP_CR1
130  */
131 #define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
132 #define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
133 #define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
134 #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
135 #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
136 /* This one is only in the PL023 variant */
137 #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
138 
139 /*
140  * SSP Status Register - SSP_SR
141  */
142 #define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
143 #define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
144 #define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
145 #define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
146 #define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
147 
148 /*
149  * SSP Clock Prescale Register  - SSP_CPSR
150  */
151 #define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
152 
153 /*
154  * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
155  */
156 #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
157 #define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
158 #define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
159 #define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
160 
161 /*
162  * SSP Raw Interrupt Status Register - SSP_RIS
163  */
164 /* Receive Overrun Raw Interrupt status */
165 #define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
166 /* Receive Timeout Raw Interrupt status */
167 #define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
168 /* Receive FIFO Raw Interrupt status */
169 #define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
170 /* Transmit FIFO Raw Interrupt status */
171 #define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
172 
173 /*
174  * SSP Masked Interrupt Status Register - SSP_MIS
175  */
176 /* Receive Overrun Masked Interrupt status */
177 #define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
178 /* Receive Timeout Masked Interrupt status */
179 #define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
180 /* Receive FIFO Masked Interrupt status */
181 #define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
182 /* Transmit FIFO Masked Interrupt status */
183 #define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
184 
185 /*
186  * SSP Interrupt Clear Register - SSP_ICR
187  */
188 /* Receive Overrun Raw Clear Interrupt bit */
189 #define SSP_ICR_MASK_RORIC		(0x1UL << 0)
190 /* Receive Timeout Clear Interrupt bit */
191 #define SSP_ICR_MASK_RTIC		(0x1UL << 1)
192 
193 /*
194  * SSP DMA Control Register - SSP_DMACR
195  */
196 /* Receive DMA Enable bit */
197 #define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
198 /* Transmit DMA Enable bit */
199 #define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
200 
201 /*
202  * SSP Chip Select Control Register - SSP_CSR
203  * (vendor extension)
204  */
205 #define SSP_CSR_CSVALUE_MASK		(0x1FUL << 0)
206 
207 /*
208  * SSP Integration Test control Register - SSP_ITCR
209  */
210 #define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
211 #define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
212 
213 /*
214  * SSP Integration Test Input Register - SSP_ITIP
215  */
216 #define ITIP_MASK_SSPRXD		 (0x1UL << 0)
217 #define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
218 #define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
219 #define ITIP_MASK_RXDMAC		 (0x1UL << 3)
220 #define ITIP_MASK_TXDMAC		 (0x1UL << 4)
221 #define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
222 
223 /*
224  * SSP Integration Test output Register - SSP_ITOP
225  */
226 #define ITOP_MASK_SSPTXD		 (0x1UL << 0)
227 #define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
228 #define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
229 #define ITOP_MASK_SSPOEn		 (0x1UL << 3)
230 #define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
231 #define ITOP_MASK_RORINTR		 (0x1UL << 5)
232 #define ITOP_MASK_RTINTR		 (0x1UL << 6)
233 #define ITOP_MASK_RXINTR		 (0x1UL << 7)
234 #define ITOP_MASK_TXINTR		 (0x1UL << 8)
235 #define ITOP_MASK_INTR			 (0x1UL << 9)
236 #define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
237 #define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
238 #define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
239 #define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
240 
241 /*
242  * SSP Test Data Register - SSP_TDR
243  */
244 #define TDR_MASK_TESTDATA		(0xFFFFFFFF)
245 
246 /*
247  * Message State
248  * we use the spi_message.state (void *) pointer to
249  * hold a single state value, that's why all this
250  * (void *) casting is done here.
251  */
252 #define STATE_START			((void *) 0)
253 #define STATE_RUNNING			((void *) 1)
254 #define STATE_DONE			((void *) 2)
255 #define STATE_ERROR			((void *) -1)
256 
257 /*
258  * SSP State - Whether Enabled or Disabled
259  */
260 #define SSP_DISABLED			(0)
261 #define SSP_ENABLED			(1)
262 
263 /*
264  * SSP DMA State - Whether DMA Enabled or Disabled
265  */
266 #define SSP_DMA_DISABLED		(0)
267 #define SSP_DMA_ENABLED			(1)
268 
269 /*
270  * SSP Clock Defaults
271  */
272 #define SSP_DEFAULT_CLKRATE 0x2
273 #define SSP_DEFAULT_PRESCALE 0x40
274 
275 /*
276  * SSP Clock Parameter ranges
277  */
278 #define CPSDVR_MIN 0x02
279 #define CPSDVR_MAX 0xFE
280 #define SCR_MIN 0x00
281 #define SCR_MAX 0xFF
282 
283 /*
284  * SSP Interrupt related Macros
285  */
286 #define DEFAULT_SSP_REG_IMSC  0x0UL
287 #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
288 #define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
289 
290 #define CLEAR_ALL_INTERRUPTS  0x3
291 
292 #define SPI_POLLING_TIMEOUT 1000
293 
294 /*
295  * The type of reading going on on this chip
296  */
297 enum ssp_reading {
298 	READING_NULL,
299 	READING_U8,
300 	READING_U16,
301 	READING_U32
302 };
303 
304 /**
305  * The type of writing going on on this chip
306  */
307 enum ssp_writing {
308 	WRITING_NULL,
309 	WRITING_U8,
310 	WRITING_U16,
311 	WRITING_U32
312 };
313 
314 /**
315  * struct vendor_data - vendor-specific config parameters
316  * for PL022 derivates
317  * @fifodepth: depth of FIFOs (both)
318  * @max_bpw: maximum number of bits per word
319  * @unidir: supports unidirection transfers
320  * @extended_cr: 32 bit wide control register 0 with extra
321  * features and extra features in CR1 as found in the ST variants
322  * @pl023: supports a subset of the ST extensions called "PL023"
323  * @internal_cs_ctrl: supports chip select control register
324  */
325 struct vendor_data {
326 	int fifodepth;
327 	int max_bpw;
328 	bool unidir;
329 	bool extended_cr;
330 	bool pl023;
331 	bool loopback;
332 	bool internal_cs_ctrl;
333 };
334 
335 /**
336  * struct pl022 - This is the private SSP driver data structure
337  * @adev: AMBA device model hookup
338  * @vendor: vendor data for the IP block
339  * @phybase: the physical memory where the SSP device resides
340  * @virtbase: the virtual memory where the SSP is mapped
341  * @clk: outgoing clock "SPICLK" for the SPI bus
342  * @master: SPI framework hookup
343  * @master_info: controller-specific data from machine setup
344  * @kworker: thread struct for message pump
345  * @kworker_task: pointer to task for message pump kworker thread
346  * @pump_messages: work struct for scheduling work to the message pump
347  * @queue_lock: spinlock to syncronise access to message queue
348  * @queue: message queue
349  * @busy: message pump is busy
350  * @running: message pump is running
351  * @pump_transfers: Tasklet used in Interrupt Transfer mode
352  * @cur_msg: Pointer to current spi_message being processed
353  * @cur_transfer: Pointer to current spi_transfer
354  * @cur_chip: pointer to current clients chip(assigned from controller_state)
355  * @next_msg_cs_active: the next message in the queue has been examined
356  *  and it was found that it uses the same chip select as the previous
357  *  message, so we left it active after the previous transfer, and it's
358  *  active already.
359  * @tx: current position in TX buffer to be read
360  * @tx_end: end position in TX buffer to be read
361  * @rx: current position in RX buffer to be written
362  * @rx_end: end position in RX buffer to be written
363  * @read: the type of read currently going on
364  * @write: the type of write currently going on
365  * @exp_fifo_level: expected FIFO level
366  * @dma_rx_channel: optional channel for RX DMA
367  * @dma_tx_channel: optional channel for TX DMA
368  * @sgt_rx: scattertable for the RX transfer
369  * @sgt_tx: scattertable for the TX transfer
370  * @dummypage: a dummy page used for driving data on the bus with DMA
371  * @cur_cs: current chip select (gpio)
372  * @chipselects: list of chipselects (gpios)
373  */
374 struct pl022 {
375 	struct amba_device		*adev;
376 	struct vendor_data		*vendor;
377 	resource_size_t			phybase;
378 	void __iomem			*virtbase;
379 	struct clk			*clk;
380 	struct spi_master		*master;
381 	struct pl022_ssp_controller	*master_info;
382 	/* Message per-transfer pump */
383 	struct tasklet_struct		pump_transfers;
384 	struct spi_message		*cur_msg;
385 	struct spi_transfer		*cur_transfer;
386 	struct chip_data		*cur_chip;
387 	bool				next_msg_cs_active;
388 	void				*tx;
389 	void				*tx_end;
390 	void				*rx;
391 	void				*rx_end;
392 	enum ssp_reading		read;
393 	enum ssp_writing		write;
394 	u32				exp_fifo_level;
395 	enum ssp_rx_level_trig		rx_lev_trig;
396 	enum ssp_tx_level_trig		tx_lev_trig;
397 	/* DMA settings */
398 #ifdef CONFIG_DMA_ENGINE
399 	struct dma_chan			*dma_rx_channel;
400 	struct dma_chan			*dma_tx_channel;
401 	struct sg_table			sgt_rx;
402 	struct sg_table			sgt_tx;
403 	char				*dummypage;
404 	bool				dma_running;
405 #endif
406 	int cur_cs;
407 	int *chipselects;
408 };
409 
410 /**
411  * struct chip_data - To maintain runtime state of SSP for each client chip
412  * @cr0: Value of control register CR0 of SSP - on later ST variants this
413  *       register is 32 bits wide rather than just 16
414  * @cr1: Value of control register CR1 of SSP
415  * @dmacr: Value of DMA control Register of SSP
416  * @cpsr: Value of Clock prescale register
417  * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
418  * @enable_dma: Whether to enable DMA or not
419  * @read: function ptr to be used to read when doing xfer for this chip
420  * @write: function ptr to be used to write when doing xfer for this chip
421  * @cs_control: chip select callback provided by chip
422  * @xfer_type: polling/interrupt/DMA
423  *
424  * Runtime state of the SSP controller, maintained per chip,
425  * This would be set according to the current message that would be served
426  */
427 struct chip_data {
428 	u32 cr0;
429 	u16 cr1;
430 	u16 dmacr;
431 	u16 cpsr;
432 	u8 n_bytes;
433 	bool enable_dma;
434 	enum ssp_reading read;
435 	enum ssp_writing write;
436 	void (*cs_control) (u32 command);
437 	int xfer_type;
438 };
439 
440 /**
441  * null_cs_control - Dummy chip select function
442  * @command: select/delect the chip
443  *
444  * If no chip select function is provided by client this is used as dummy
445  * chip select
446  */
447 static void null_cs_control(u32 command)
448 {
449 	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
450 }
451 
452 /**
453  * internal_cs_control - Control chip select signals via SSP_CSR.
454  * @pl022: SSP driver private data structure
455  * @command: select/delect the chip
456  *
457  * Used on controller with internal chip select control via SSP_CSR register
458  * (vendor extension). Each of the 5 LSB in the register controls one chip
459  * select signal.
460  */
461 static void internal_cs_control(struct pl022 *pl022, u32 command)
462 {
463 	u32 tmp;
464 
465 	tmp = readw(SSP_CSR(pl022->virtbase));
466 	if (command == SSP_CHIP_SELECT)
467 		tmp &= ~BIT(pl022->cur_cs);
468 	else
469 		tmp |= BIT(pl022->cur_cs);
470 	writew(tmp, SSP_CSR(pl022->virtbase));
471 }
472 
473 static void pl022_cs_control(struct pl022 *pl022, u32 command)
474 {
475 	if (pl022->vendor->internal_cs_ctrl)
476 		internal_cs_control(pl022, command);
477 	else if (gpio_is_valid(pl022->cur_cs))
478 		gpio_set_value(pl022->cur_cs, command);
479 	else
480 		pl022->cur_chip->cs_control(command);
481 }
482 
483 /**
484  * giveback - current spi_message is over, schedule next message and call
485  * callback of this message. Assumes that caller already
486  * set message->status; dma and pio irqs are blocked
487  * @pl022: SSP driver private data structure
488  */
489 static void giveback(struct pl022 *pl022)
490 {
491 	struct spi_transfer *last_transfer;
492 	pl022->next_msg_cs_active = false;
493 
494 	last_transfer = list_last_entry(&pl022->cur_msg->transfers,
495 					struct spi_transfer, transfer_list);
496 
497 	/* Delay if requested before any change in chip select */
498 	if (last_transfer->delay_usecs)
499 		/*
500 		 * FIXME: This runs in interrupt context.
501 		 * Is this really smart?
502 		 */
503 		udelay(last_transfer->delay_usecs);
504 
505 	if (!last_transfer->cs_change) {
506 		struct spi_message *next_msg;
507 
508 		/*
509 		 * cs_change was not set. We can keep the chip select
510 		 * enabled if there is message in the queue and it is
511 		 * for the same spi device.
512 		 *
513 		 * We cannot postpone this until pump_messages, because
514 		 * after calling msg->complete (below) the driver that
515 		 * sent the current message could be unloaded, which
516 		 * could invalidate the cs_control() callback...
517 		 */
518 		/* get a pointer to the next message, if any */
519 		next_msg = spi_get_next_queued_message(pl022->master);
520 
521 		/*
522 		 * see if the next and current messages point
523 		 * to the same spi device.
524 		 */
525 		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
526 			next_msg = NULL;
527 		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
528 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
529 		else
530 			pl022->next_msg_cs_active = true;
531 
532 	}
533 
534 	pl022->cur_msg = NULL;
535 	pl022->cur_transfer = NULL;
536 	pl022->cur_chip = NULL;
537 
538 	/* disable the SPI/SSP operation */
539 	writew((readw(SSP_CR1(pl022->virtbase)) &
540 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
541 
542 	spi_finalize_current_message(pl022->master);
543 }
544 
545 /**
546  * flush - flush the FIFO to reach a clean state
547  * @pl022: SSP driver private data structure
548  */
549 static int flush(struct pl022 *pl022)
550 {
551 	unsigned long limit = loops_per_jiffy << 1;
552 
553 	dev_dbg(&pl022->adev->dev, "flush\n");
554 	do {
555 		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
556 			readw(SSP_DR(pl022->virtbase));
557 	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
558 
559 	pl022->exp_fifo_level = 0;
560 
561 	return limit;
562 }
563 
564 /**
565  * restore_state - Load configuration of current chip
566  * @pl022: SSP driver private data structure
567  */
568 static void restore_state(struct pl022 *pl022)
569 {
570 	struct chip_data *chip = pl022->cur_chip;
571 
572 	if (pl022->vendor->extended_cr)
573 		writel(chip->cr0, SSP_CR0(pl022->virtbase));
574 	else
575 		writew(chip->cr0, SSP_CR0(pl022->virtbase));
576 	writew(chip->cr1, SSP_CR1(pl022->virtbase));
577 	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
578 	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
579 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
580 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
581 }
582 
583 /*
584  * Default SSP Register Values
585  */
586 #define DEFAULT_SSP_REG_CR0 ( \
587 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
588 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
589 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
590 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
591 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
592 )
593 
594 /* ST versions have slightly different bit layout */
595 #define DEFAULT_SSP_REG_CR0_ST ( \
596 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
597 	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
598 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
599 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
600 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
601 	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
602 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
603 )
604 
605 /* The PL023 version is slightly different again */
606 #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
607 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
608 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
609 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
610 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
611 )
612 
613 #define DEFAULT_SSP_REG_CR1 ( \
614 	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
615 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
616 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
617 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
618 )
619 
620 /* ST versions extend this register to use all 16 bits */
621 #define DEFAULT_SSP_REG_CR1_ST ( \
622 	DEFAULT_SSP_REG_CR1 | \
623 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
624 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
625 	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
626 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
627 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
628 )
629 
630 /*
631  * The PL023 variant has further differences: no loopback mode, no microwire
632  * support, and a new clock feedback delay setting.
633  */
634 #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
635 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
636 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
637 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
638 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
639 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
640 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
641 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
642 	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
643 )
644 
645 #define DEFAULT_SSP_REG_CPSR ( \
646 	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
647 )
648 
649 #define DEFAULT_SSP_REG_DMACR (\
650 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
651 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
652 )
653 
654 /**
655  * load_ssp_default_config - Load default configuration for SSP
656  * @pl022: SSP driver private data structure
657  */
658 static void load_ssp_default_config(struct pl022 *pl022)
659 {
660 	if (pl022->vendor->pl023) {
661 		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
662 		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
663 	} else if (pl022->vendor->extended_cr) {
664 		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
665 		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
666 	} else {
667 		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
668 		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
669 	}
670 	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
671 	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
672 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
673 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
674 }
675 
676 /**
677  * This will write to TX and read from RX according to the parameters
678  * set in pl022.
679  */
680 static void readwriter(struct pl022 *pl022)
681 {
682 
683 	/*
684 	 * The FIFO depth is different between primecell variants.
685 	 * I believe filling in too much in the FIFO might cause
686 	 * errons in 8bit wide transfers on ARM variants (just 8 words
687 	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
688 	 *
689 	 * To prevent this issue, the TX FIFO is only filled to the
690 	 * unused RX FIFO fill length, regardless of what the TX
691 	 * FIFO status flag indicates.
692 	 */
693 	dev_dbg(&pl022->adev->dev,
694 		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
695 		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
696 
697 	/* Read as much as you can */
698 	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
699 	       && (pl022->rx < pl022->rx_end)) {
700 		switch (pl022->read) {
701 		case READING_NULL:
702 			readw(SSP_DR(pl022->virtbase));
703 			break;
704 		case READING_U8:
705 			*(u8 *) (pl022->rx) =
706 				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
707 			break;
708 		case READING_U16:
709 			*(u16 *) (pl022->rx) =
710 				(u16) readw(SSP_DR(pl022->virtbase));
711 			break;
712 		case READING_U32:
713 			*(u32 *) (pl022->rx) =
714 				readl(SSP_DR(pl022->virtbase));
715 			break;
716 		}
717 		pl022->rx += (pl022->cur_chip->n_bytes);
718 		pl022->exp_fifo_level--;
719 	}
720 	/*
721 	 * Write as much as possible up to the RX FIFO size
722 	 */
723 	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
724 	       && (pl022->tx < pl022->tx_end)) {
725 		switch (pl022->write) {
726 		case WRITING_NULL:
727 			writew(0x0, SSP_DR(pl022->virtbase));
728 			break;
729 		case WRITING_U8:
730 			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
731 			break;
732 		case WRITING_U16:
733 			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
734 			break;
735 		case WRITING_U32:
736 			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
737 			break;
738 		}
739 		pl022->tx += (pl022->cur_chip->n_bytes);
740 		pl022->exp_fifo_level++;
741 		/*
742 		 * This inner reader takes care of things appearing in the RX
743 		 * FIFO as we're transmitting. This will happen a lot since the
744 		 * clock starts running when you put things into the TX FIFO,
745 		 * and then things are continuously clocked into the RX FIFO.
746 		 */
747 		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
748 		       && (pl022->rx < pl022->rx_end)) {
749 			switch (pl022->read) {
750 			case READING_NULL:
751 				readw(SSP_DR(pl022->virtbase));
752 				break;
753 			case READING_U8:
754 				*(u8 *) (pl022->rx) =
755 					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
756 				break;
757 			case READING_U16:
758 				*(u16 *) (pl022->rx) =
759 					(u16) readw(SSP_DR(pl022->virtbase));
760 				break;
761 			case READING_U32:
762 				*(u32 *) (pl022->rx) =
763 					readl(SSP_DR(pl022->virtbase));
764 				break;
765 			}
766 			pl022->rx += (pl022->cur_chip->n_bytes);
767 			pl022->exp_fifo_level--;
768 		}
769 	}
770 	/*
771 	 * When we exit here the TX FIFO should be full and the RX FIFO
772 	 * should be empty
773 	 */
774 }
775 
776 /**
777  * next_transfer - Move to the Next transfer in the current spi message
778  * @pl022: SSP driver private data structure
779  *
780  * This function moves though the linked list of spi transfers in the
781  * current spi message and returns with the state of current spi
782  * message i.e whether its last transfer is done(STATE_DONE) or
783  * Next transfer is ready(STATE_RUNNING)
784  */
785 static void *next_transfer(struct pl022 *pl022)
786 {
787 	struct spi_message *msg = pl022->cur_msg;
788 	struct spi_transfer *trans = pl022->cur_transfer;
789 
790 	/* Move to next transfer */
791 	if (trans->transfer_list.next != &msg->transfers) {
792 		pl022->cur_transfer =
793 		    list_entry(trans->transfer_list.next,
794 			       struct spi_transfer, transfer_list);
795 		return STATE_RUNNING;
796 	}
797 	return STATE_DONE;
798 }
799 
800 /*
801  * This DMA functionality is only compiled in if we have
802  * access to the generic DMA devices/DMA engine.
803  */
804 #ifdef CONFIG_DMA_ENGINE
805 static void unmap_free_dma_scatter(struct pl022 *pl022)
806 {
807 	/* Unmap and free the SG tables */
808 	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
809 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
810 	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
811 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
812 	sg_free_table(&pl022->sgt_rx);
813 	sg_free_table(&pl022->sgt_tx);
814 }
815 
816 static void dma_callback(void *data)
817 {
818 	struct pl022 *pl022 = data;
819 	struct spi_message *msg = pl022->cur_msg;
820 
821 	BUG_ON(!pl022->sgt_rx.sgl);
822 
823 #ifdef VERBOSE_DEBUG
824 	/*
825 	 * Optionally dump out buffers to inspect contents, this is
826 	 * good if you want to convince yourself that the loopback
827 	 * read/write contents are the same, when adopting to a new
828 	 * DMA engine.
829 	 */
830 	{
831 		struct scatterlist *sg;
832 		unsigned int i;
833 
834 		dma_sync_sg_for_cpu(&pl022->adev->dev,
835 				    pl022->sgt_rx.sgl,
836 				    pl022->sgt_rx.nents,
837 				    DMA_FROM_DEVICE);
838 
839 		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
840 			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
841 			print_hex_dump(KERN_ERR, "SPI RX: ",
842 				       DUMP_PREFIX_OFFSET,
843 				       16,
844 				       1,
845 				       sg_virt(sg),
846 				       sg_dma_len(sg),
847 				       1);
848 		}
849 		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
850 			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
851 			print_hex_dump(KERN_ERR, "SPI TX: ",
852 				       DUMP_PREFIX_OFFSET,
853 				       16,
854 				       1,
855 				       sg_virt(sg),
856 				       sg_dma_len(sg),
857 				       1);
858 		}
859 	}
860 #endif
861 
862 	unmap_free_dma_scatter(pl022);
863 
864 	/* Update total bytes transferred */
865 	msg->actual_length += pl022->cur_transfer->len;
866 	if (pl022->cur_transfer->cs_change)
867 		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
868 
869 	/* Move to next transfer */
870 	msg->state = next_transfer(pl022);
871 	tasklet_schedule(&pl022->pump_transfers);
872 }
873 
874 static void setup_dma_scatter(struct pl022 *pl022,
875 			      void *buffer,
876 			      unsigned int length,
877 			      struct sg_table *sgtab)
878 {
879 	struct scatterlist *sg;
880 	int bytesleft = length;
881 	void *bufp = buffer;
882 	int mapbytes;
883 	int i;
884 
885 	if (buffer) {
886 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
887 			/*
888 			 * If there are less bytes left than what fits
889 			 * in the current page (plus page alignment offset)
890 			 * we just feed in this, else we stuff in as much
891 			 * as we can.
892 			 */
893 			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
894 				mapbytes = bytesleft;
895 			else
896 				mapbytes = PAGE_SIZE - offset_in_page(bufp);
897 			sg_set_page(sg, virt_to_page(bufp),
898 				    mapbytes, offset_in_page(bufp));
899 			bufp += mapbytes;
900 			bytesleft -= mapbytes;
901 			dev_dbg(&pl022->adev->dev,
902 				"set RX/TX target page @ %p, %d bytes, %d left\n",
903 				bufp, mapbytes, bytesleft);
904 		}
905 	} else {
906 		/* Map the dummy buffer on every page */
907 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
908 			if (bytesleft < PAGE_SIZE)
909 				mapbytes = bytesleft;
910 			else
911 				mapbytes = PAGE_SIZE;
912 			sg_set_page(sg, virt_to_page(pl022->dummypage),
913 				    mapbytes, 0);
914 			bytesleft -= mapbytes;
915 			dev_dbg(&pl022->adev->dev,
916 				"set RX/TX to dummy page %d bytes, %d left\n",
917 				mapbytes, bytesleft);
918 
919 		}
920 	}
921 	BUG_ON(bytesleft);
922 }
923 
924 /**
925  * configure_dma - configures the channels for the next transfer
926  * @pl022: SSP driver's private data structure
927  */
928 static int configure_dma(struct pl022 *pl022)
929 {
930 	struct dma_slave_config rx_conf = {
931 		.src_addr = SSP_DR(pl022->phybase),
932 		.direction = DMA_DEV_TO_MEM,
933 		.device_fc = false,
934 	};
935 	struct dma_slave_config tx_conf = {
936 		.dst_addr = SSP_DR(pl022->phybase),
937 		.direction = DMA_MEM_TO_DEV,
938 		.device_fc = false,
939 	};
940 	unsigned int pages;
941 	int ret;
942 	int rx_sglen, tx_sglen;
943 	struct dma_chan *rxchan = pl022->dma_rx_channel;
944 	struct dma_chan *txchan = pl022->dma_tx_channel;
945 	struct dma_async_tx_descriptor *rxdesc;
946 	struct dma_async_tx_descriptor *txdesc;
947 
948 	/* Check that the channels are available */
949 	if (!rxchan || !txchan)
950 		return -ENODEV;
951 
952 	/*
953 	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
954 	 * Notice that the DMA engine uses one-to-one mapping. Since we can
955 	 * not trigger on 2 elements this needs explicit mapping rather than
956 	 * calculation.
957 	 */
958 	switch (pl022->rx_lev_trig) {
959 	case SSP_RX_1_OR_MORE_ELEM:
960 		rx_conf.src_maxburst = 1;
961 		break;
962 	case SSP_RX_4_OR_MORE_ELEM:
963 		rx_conf.src_maxburst = 4;
964 		break;
965 	case SSP_RX_8_OR_MORE_ELEM:
966 		rx_conf.src_maxburst = 8;
967 		break;
968 	case SSP_RX_16_OR_MORE_ELEM:
969 		rx_conf.src_maxburst = 16;
970 		break;
971 	case SSP_RX_32_OR_MORE_ELEM:
972 		rx_conf.src_maxburst = 32;
973 		break;
974 	default:
975 		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
976 		break;
977 	}
978 
979 	switch (pl022->tx_lev_trig) {
980 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
981 		tx_conf.dst_maxburst = 1;
982 		break;
983 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
984 		tx_conf.dst_maxburst = 4;
985 		break;
986 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
987 		tx_conf.dst_maxburst = 8;
988 		break;
989 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
990 		tx_conf.dst_maxburst = 16;
991 		break;
992 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
993 		tx_conf.dst_maxburst = 32;
994 		break;
995 	default:
996 		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
997 		break;
998 	}
999 
1000 	switch (pl022->read) {
1001 	case READING_NULL:
1002 		/* Use the same as for writing */
1003 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1004 		break;
1005 	case READING_U8:
1006 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1007 		break;
1008 	case READING_U16:
1009 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1010 		break;
1011 	case READING_U32:
1012 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1013 		break;
1014 	}
1015 
1016 	switch (pl022->write) {
1017 	case WRITING_NULL:
1018 		/* Use the same as for reading */
1019 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1020 		break;
1021 	case WRITING_U8:
1022 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1023 		break;
1024 	case WRITING_U16:
1025 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1026 		break;
1027 	case WRITING_U32:
1028 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1029 		break;
1030 	}
1031 
1032 	/* SPI pecularity: we need to read and write the same width */
1033 	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1034 		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1035 	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1036 		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1037 	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1038 
1039 	dmaengine_slave_config(rxchan, &rx_conf);
1040 	dmaengine_slave_config(txchan, &tx_conf);
1041 
1042 	/* Create sglists for the transfers */
1043 	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1044 	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1045 
1046 	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1047 	if (ret)
1048 		goto err_alloc_rx_sg;
1049 
1050 	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1051 	if (ret)
1052 		goto err_alloc_tx_sg;
1053 
1054 	/* Fill in the scatterlists for the RX+TX buffers */
1055 	setup_dma_scatter(pl022, pl022->rx,
1056 			  pl022->cur_transfer->len, &pl022->sgt_rx);
1057 	setup_dma_scatter(pl022, pl022->tx,
1058 			  pl022->cur_transfer->len, &pl022->sgt_tx);
1059 
1060 	/* Map DMA buffers */
1061 	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1062 			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1063 	if (!rx_sglen)
1064 		goto err_rx_sgmap;
1065 
1066 	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1067 			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1068 	if (!tx_sglen)
1069 		goto err_tx_sgmap;
1070 
1071 	/* Send both scatterlists */
1072 	rxdesc = dmaengine_prep_slave_sg(rxchan,
1073 				      pl022->sgt_rx.sgl,
1074 				      rx_sglen,
1075 				      DMA_DEV_TO_MEM,
1076 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1077 	if (!rxdesc)
1078 		goto err_rxdesc;
1079 
1080 	txdesc = dmaengine_prep_slave_sg(txchan,
1081 				      pl022->sgt_tx.sgl,
1082 				      tx_sglen,
1083 				      DMA_MEM_TO_DEV,
1084 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1085 	if (!txdesc)
1086 		goto err_txdesc;
1087 
1088 	/* Put the callback on the RX transfer only, that should finish last */
1089 	rxdesc->callback = dma_callback;
1090 	rxdesc->callback_param = pl022;
1091 
1092 	/* Submit and fire RX and TX with TX last so we're ready to read! */
1093 	dmaengine_submit(rxdesc);
1094 	dmaengine_submit(txdesc);
1095 	dma_async_issue_pending(rxchan);
1096 	dma_async_issue_pending(txchan);
1097 	pl022->dma_running = true;
1098 
1099 	return 0;
1100 
1101 err_txdesc:
1102 	dmaengine_terminate_all(txchan);
1103 err_rxdesc:
1104 	dmaengine_terminate_all(rxchan);
1105 	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1106 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1107 err_tx_sgmap:
1108 	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1109 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1110 err_rx_sgmap:
1111 	sg_free_table(&pl022->sgt_tx);
1112 err_alloc_tx_sg:
1113 	sg_free_table(&pl022->sgt_rx);
1114 err_alloc_rx_sg:
1115 	return -ENOMEM;
1116 }
1117 
1118 static int pl022_dma_probe(struct pl022 *pl022)
1119 {
1120 	dma_cap_mask_t mask;
1121 
1122 	/* Try to acquire a generic DMA engine slave channel */
1123 	dma_cap_zero(mask);
1124 	dma_cap_set(DMA_SLAVE, mask);
1125 	/*
1126 	 * We need both RX and TX channels to do DMA, else do none
1127 	 * of them.
1128 	 */
1129 	pl022->dma_rx_channel = dma_request_channel(mask,
1130 					    pl022->master_info->dma_filter,
1131 					    pl022->master_info->dma_rx_param);
1132 	if (!pl022->dma_rx_channel) {
1133 		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1134 		goto err_no_rxchan;
1135 	}
1136 
1137 	pl022->dma_tx_channel = dma_request_channel(mask,
1138 					    pl022->master_info->dma_filter,
1139 					    pl022->master_info->dma_tx_param);
1140 	if (!pl022->dma_tx_channel) {
1141 		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1142 		goto err_no_txchan;
1143 	}
1144 
1145 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1146 	if (!pl022->dummypage)
1147 		goto err_no_dummypage;
1148 
1149 	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1150 		 dma_chan_name(pl022->dma_rx_channel),
1151 		 dma_chan_name(pl022->dma_tx_channel));
1152 
1153 	return 0;
1154 
1155 err_no_dummypage:
1156 	dma_release_channel(pl022->dma_tx_channel);
1157 err_no_txchan:
1158 	dma_release_channel(pl022->dma_rx_channel);
1159 	pl022->dma_rx_channel = NULL;
1160 err_no_rxchan:
1161 	dev_err(&pl022->adev->dev,
1162 			"Failed to work in dma mode, work without dma!\n");
1163 	return -ENODEV;
1164 }
1165 
1166 static int pl022_dma_autoprobe(struct pl022 *pl022)
1167 {
1168 	struct device *dev = &pl022->adev->dev;
1169 
1170 	/* automatically configure DMA channels from platform, normally using DT */
1171 	pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx");
1172 	if (!pl022->dma_rx_channel)
1173 		goto err_no_rxchan;
1174 
1175 	pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx");
1176 	if (!pl022->dma_tx_channel)
1177 		goto err_no_txchan;
1178 
1179 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1180 	if (!pl022->dummypage)
1181 		goto err_no_dummypage;
1182 
1183 	return 0;
1184 
1185 err_no_dummypage:
1186 	dma_release_channel(pl022->dma_tx_channel);
1187 	pl022->dma_tx_channel = NULL;
1188 err_no_txchan:
1189 	dma_release_channel(pl022->dma_rx_channel);
1190 	pl022->dma_rx_channel = NULL;
1191 err_no_rxchan:
1192 	return -ENODEV;
1193 }
1194 
1195 static void terminate_dma(struct pl022 *pl022)
1196 {
1197 	struct dma_chan *rxchan = pl022->dma_rx_channel;
1198 	struct dma_chan *txchan = pl022->dma_tx_channel;
1199 
1200 	dmaengine_terminate_all(rxchan);
1201 	dmaengine_terminate_all(txchan);
1202 	unmap_free_dma_scatter(pl022);
1203 	pl022->dma_running = false;
1204 }
1205 
1206 static void pl022_dma_remove(struct pl022 *pl022)
1207 {
1208 	if (pl022->dma_running)
1209 		terminate_dma(pl022);
1210 	if (pl022->dma_tx_channel)
1211 		dma_release_channel(pl022->dma_tx_channel);
1212 	if (pl022->dma_rx_channel)
1213 		dma_release_channel(pl022->dma_rx_channel);
1214 	kfree(pl022->dummypage);
1215 }
1216 
1217 #else
1218 static inline int configure_dma(struct pl022 *pl022)
1219 {
1220 	return -ENODEV;
1221 }
1222 
1223 static inline int pl022_dma_autoprobe(struct pl022 *pl022)
1224 {
1225 	return 0;
1226 }
1227 
1228 static inline int pl022_dma_probe(struct pl022 *pl022)
1229 {
1230 	return 0;
1231 }
1232 
1233 static inline void pl022_dma_remove(struct pl022 *pl022)
1234 {
1235 }
1236 #endif
1237 
1238 /**
1239  * pl022_interrupt_handler - Interrupt handler for SSP controller
1240  *
1241  * This function handles interrupts generated for an interrupt based transfer.
1242  * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1243  * current message's state as STATE_ERROR and schedule the tasklet
1244  * pump_transfers which will do the postprocessing of the current message by
1245  * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1246  * more data, and writes data in TX FIFO till it is not full. If we complete
1247  * the transfer we move to the next transfer and schedule the tasklet.
1248  */
1249 static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1250 {
1251 	struct pl022 *pl022 = dev_id;
1252 	struct spi_message *msg = pl022->cur_msg;
1253 	u16 irq_status = 0;
1254 	u16 flag = 0;
1255 
1256 	if (unlikely(!msg)) {
1257 		dev_err(&pl022->adev->dev,
1258 			"bad message state in interrupt handler");
1259 		/* Never fail */
1260 		return IRQ_HANDLED;
1261 	}
1262 
1263 	/* Read the Interrupt Status Register */
1264 	irq_status = readw(SSP_MIS(pl022->virtbase));
1265 
1266 	if (unlikely(!irq_status))
1267 		return IRQ_NONE;
1268 
1269 	/*
1270 	 * This handles the FIFO interrupts, the timeout
1271 	 * interrupts are flatly ignored, they cannot be
1272 	 * trusted.
1273 	 */
1274 	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1275 		/*
1276 		 * Overrun interrupt - bail out since our Data has been
1277 		 * corrupted
1278 		 */
1279 		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1280 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1281 			dev_err(&pl022->adev->dev,
1282 				"RXFIFO is full\n");
1283 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
1284 			dev_err(&pl022->adev->dev,
1285 				"TXFIFO is full\n");
1286 
1287 		/*
1288 		 * Disable and clear interrupts, disable SSP,
1289 		 * mark message with bad status so it can be
1290 		 * retried.
1291 		 */
1292 		writew(DISABLE_ALL_INTERRUPTS,
1293 		       SSP_IMSC(pl022->virtbase));
1294 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1295 		writew((readw(SSP_CR1(pl022->virtbase)) &
1296 			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1297 		msg->state = STATE_ERROR;
1298 
1299 		/* Schedule message queue handler */
1300 		tasklet_schedule(&pl022->pump_transfers);
1301 		return IRQ_HANDLED;
1302 	}
1303 
1304 	readwriter(pl022);
1305 
1306 	if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
1307 		flag = 1;
1308 		/* Disable Transmit interrupt, enable receive interrupt */
1309 		writew((readw(SSP_IMSC(pl022->virtbase)) &
1310 		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1311 		       SSP_IMSC(pl022->virtbase));
1312 	}
1313 
1314 	/*
1315 	 * Since all transactions must write as much as shall be read,
1316 	 * we can conclude the entire transaction once RX is complete.
1317 	 * At this point, all TX will always be finished.
1318 	 */
1319 	if (pl022->rx >= pl022->rx_end) {
1320 		writew(DISABLE_ALL_INTERRUPTS,
1321 		       SSP_IMSC(pl022->virtbase));
1322 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1323 		if (unlikely(pl022->rx > pl022->rx_end)) {
1324 			dev_warn(&pl022->adev->dev, "read %u surplus "
1325 				 "bytes (did you request an odd "
1326 				 "number of bytes on a 16bit bus?)\n",
1327 				 (u32) (pl022->rx - pl022->rx_end));
1328 		}
1329 		/* Update total bytes transferred */
1330 		msg->actual_length += pl022->cur_transfer->len;
1331 		if (pl022->cur_transfer->cs_change)
1332 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1333 		/* Move to next transfer */
1334 		msg->state = next_transfer(pl022);
1335 		tasklet_schedule(&pl022->pump_transfers);
1336 		return IRQ_HANDLED;
1337 	}
1338 
1339 	return IRQ_HANDLED;
1340 }
1341 
1342 /**
1343  * This sets up the pointers to memory for the next message to
1344  * send out on the SPI bus.
1345  */
1346 static int set_up_next_transfer(struct pl022 *pl022,
1347 				struct spi_transfer *transfer)
1348 {
1349 	int residue;
1350 
1351 	/* Sanity check the message for this bus width */
1352 	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1353 	if (unlikely(residue != 0)) {
1354 		dev_err(&pl022->adev->dev,
1355 			"message of %u bytes to transmit but the current "
1356 			"chip bus has a data width of %u bytes!\n",
1357 			pl022->cur_transfer->len,
1358 			pl022->cur_chip->n_bytes);
1359 		dev_err(&pl022->adev->dev, "skipping this message\n");
1360 		return -EIO;
1361 	}
1362 	pl022->tx = (void *)transfer->tx_buf;
1363 	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1364 	pl022->rx = (void *)transfer->rx_buf;
1365 	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1366 	pl022->write =
1367 	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1368 	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1369 	return 0;
1370 }
1371 
1372 /**
1373  * pump_transfers - Tasklet function which schedules next transfer
1374  * when running in interrupt or DMA transfer mode.
1375  * @data: SSP driver private data structure
1376  *
1377  */
1378 static void pump_transfers(unsigned long data)
1379 {
1380 	struct pl022 *pl022 = (struct pl022 *) data;
1381 	struct spi_message *message = NULL;
1382 	struct spi_transfer *transfer = NULL;
1383 	struct spi_transfer *previous = NULL;
1384 
1385 	/* Get current state information */
1386 	message = pl022->cur_msg;
1387 	transfer = pl022->cur_transfer;
1388 
1389 	/* Handle for abort */
1390 	if (message->state == STATE_ERROR) {
1391 		message->status = -EIO;
1392 		giveback(pl022);
1393 		return;
1394 	}
1395 
1396 	/* Handle end of message */
1397 	if (message->state == STATE_DONE) {
1398 		message->status = 0;
1399 		giveback(pl022);
1400 		return;
1401 	}
1402 
1403 	/* Delay if requested at end of transfer before CS change */
1404 	if (message->state == STATE_RUNNING) {
1405 		previous = list_entry(transfer->transfer_list.prev,
1406 					struct spi_transfer,
1407 					transfer_list);
1408 		if (previous->delay_usecs)
1409 			/*
1410 			 * FIXME: This runs in interrupt context.
1411 			 * Is this really smart?
1412 			 */
1413 			udelay(previous->delay_usecs);
1414 
1415 		/* Reselect chip select only if cs_change was requested */
1416 		if (previous->cs_change)
1417 			pl022_cs_control(pl022, SSP_CHIP_SELECT);
1418 	} else {
1419 		/* STATE_START */
1420 		message->state = STATE_RUNNING;
1421 	}
1422 
1423 	if (set_up_next_transfer(pl022, transfer)) {
1424 		message->state = STATE_ERROR;
1425 		message->status = -EIO;
1426 		giveback(pl022);
1427 		return;
1428 	}
1429 	/* Flush the FIFOs and let's go! */
1430 	flush(pl022);
1431 
1432 	if (pl022->cur_chip->enable_dma) {
1433 		if (configure_dma(pl022)) {
1434 			dev_dbg(&pl022->adev->dev,
1435 				"configuration of DMA failed, fall back to interrupt mode\n");
1436 			goto err_config_dma;
1437 		}
1438 		return;
1439 	}
1440 
1441 err_config_dma:
1442 	/* enable all interrupts except RX */
1443 	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1444 }
1445 
1446 static void do_interrupt_dma_transfer(struct pl022 *pl022)
1447 {
1448 	/*
1449 	 * Default is to enable all interrupts except RX -
1450 	 * this will be enabled once TX is complete
1451 	 */
1452 	u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
1453 
1454 	/* Enable target chip, if not already active */
1455 	if (!pl022->next_msg_cs_active)
1456 		pl022_cs_control(pl022, SSP_CHIP_SELECT);
1457 
1458 	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1459 		/* Error path */
1460 		pl022->cur_msg->state = STATE_ERROR;
1461 		pl022->cur_msg->status = -EIO;
1462 		giveback(pl022);
1463 		return;
1464 	}
1465 	/* If we're using DMA, set up DMA here */
1466 	if (pl022->cur_chip->enable_dma) {
1467 		/* Configure DMA transfer */
1468 		if (configure_dma(pl022)) {
1469 			dev_dbg(&pl022->adev->dev,
1470 				"configuration of DMA failed, fall back to interrupt mode\n");
1471 			goto err_config_dma;
1472 		}
1473 		/* Disable interrupts in DMA mode, IRQ from DMA controller */
1474 		irqflags = DISABLE_ALL_INTERRUPTS;
1475 	}
1476 err_config_dma:
1477 	/* Enable SSP, turn on interrupts */
1478 	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1479 	       SSP_CR1(pl022->virtbase));
1480 	writew(irqflags, SSP_IMSC(pl022->virtbase));
1481 }
1482 
1483 static void do_polling_transfer(struct pl022 *pl022)
1484 {
1485 	struct spi_message *message = NULL;
1486 	struct spi_transfer *transfer = NULL;
1487 	struct spi_transfer *previous = NULL;
1488 	struct chip_data *chip;
1489 	unsigned long time, timeout;
1490 
1491 	chip = pl022->cur_chip;
1492 	message = pl022->cur_msg;
1493 
1494 	while (message->state != STATE_DONE) {
1495 		/* Handle for abort */
1496 		if (message->state == STATE_ERROR)
1497 			break;
1498 		transfer = pl022->cur_transfer;
1499 
1500 		/* Delay if requested at end of transfer */
1501 		if (message->state == STATE_RUNNING) {
1502 			previous =
1503 			    list_entry(transfer->transfer_list.prev,
1504 				       struct spi_transfer, transfer_list);
1505 			if (previous->delay_usecs)
1506 				udelay(previous->delay_usecs);
1507 			if (previous->cs_change)
1508 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1509 		} else {
1510 			/* STATE_START */
1511 			message->state = STATE_RUNNING;
1512 			if (!pl022->next_msg_cs_active)
1513 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1514 		}
1515 
1516 		/* Configuration Changing Per Transfer */
1517 		if (set_up_next_transfer(pl022, transfer)) {
1518 			/* Error path */
1519 			message->state = STATE_ERROR;
1520 			break;
1521 		}
1522 		/* Flush FIFOs and enable SSP */
1523 		flush(pl022);
1524 		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1525 		       SSP_CR1(pl022->virtbase));
1526 
1527 		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1528 
1529 		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1530 		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1531 			time = jiffies;
1532 			readwriter(pl022);
1533 			if (time_after(time, timeout)) {
1534 				dev_warn(&pl022->adev->dev,
1535 				"%s: timeout!\n", __func__);
1536 				message->state = STATE_ERROR;
1537 				goto out;
1538 			}
1539 			cpu_relax();
1540 		}
1541 
1542 		/* Update total byte transferred */
1543 		message->actual_length += pl022->cur_transfer->len;
1544 		if (pl022->cur_transfer->cs_change)
1545 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1546 		/* Move to next transfer */
1547 		message->state = next_transfer(pl022);
1548 	}
1549 out:
1550 	/* Handle end of message */
1551 	if (message->state == STATE_DONE)
1552 		message->status = 0;
1553 	else
1554 		message->status = -EIO;
1555 
1556 	giveback(pl022);
1557 	return;
1558 }
1559 
1560 static int pl022_transfer_one_message(struct spi_master *master,
1561 				      struct spi_message *msg)
1562 {
1563 	struct pl022 *pl022 = spi_master_get_devdata(master);
1564 
1565 	/* Initial message state */
1566 	pl022->cur_msg = msg;
1567 	msg->state = STATE_START;
1568 
1569 	pl022->cur_transfer = list_entry(msg->transfers.next,
1570 					 struct spi_transfer, transfer_list);
1571 
1572 	/* Setup the SPI using the per chip configuration */
1573 	pl022->cur_chip = spi_get_ctldata(msg->spi);
1574 	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1575 
1576 	restore_state(pl022);
1577 	flush(pl022);
1578 
1579 	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1580 		do_polling_transfer(pl022);
1581 	else
1582 		do_interrupt_dma_transfer(pl022);
1583 
1584 	return 0;
1585 }
1586 
1587 static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1588 {
1589 	struct pl022 *pl022 = spi_master_get_devdata(master);
1590 
1591 	/* nothing more to do - disable spi/ssp and power off */
1592 	writew((readw(SSP_CR1(pl022->virtbase)) &
1593 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1594 
1595 	return 0;
1596 }
1597 
1598 static int verify_controller_parameters(struct pl022 *pl022,
1599 				struct pl022_config_chip const *chip_info)
1600 {
1601 	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1602 	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1603 		dev_err(&pl022->adev->dev,
1604 			"interface is configured incorrectly\n");
1605 		return -EINVAL;
1606 	}
1607 	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1608 	    (!pl022->vendor->unidir)) {
1609 		dev_err(&pl022->adev->dev,
1610 			"unidirectional mode not supported in this "
1611 			"hardware version\n");
1612 		return -EINVAL;
1613 	}
1614 	if ((chip_info->hierarchy != SSP_MASTER)
1615 	    && (chip_info->hierarchy != SSP_SLAVE)) {
1616 		dev_err(&pl022->adev->dev,
1617 			"hierarchy is configured incorrectly\n");
1618 		return -EINVAL;
1619 	}
1620 	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1621 	    && (chip_info->com_mode != DMA_TRANSFER)
1622 	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1623 		dev_err(&pl022->adev->dev,
1624 			"Communication mode is configured incorrectly\n");
1625 		return -EINVAL;
1626 	}
1627 	switch (chip_info->rx_lev_trig) {
1628 	case SSP_RX_1_OR_MORE_ELEM:
1629 	case SSP_RX_4_OR_MORE_ELEM:
1630 	case SSP_RX_8_OR_MORE_ELEM:
1631 		/* These are always OK, all variants can handle this */
1632 		break;
1633 	case SSP_RX_16_OR_MORE_ELEM:
1634 		if (pl022->vendor->fifodepth < 16) {
1635 			dev_err(&pl022->adev->dev,
1636 			"RX FIFO Trigger Level is configured incorrectly\n");
1637 			return -EINVAL;
1638 		}
1639 		break;
1640 	case SSP_RX_32_OR_MORE_ELEM:
1641 		if (pl022->vendor->fifodepth < 32) {
1642 			dev_err(&pl022->adev->dev,
1643 			"RX FIFO Trigger Level is configured incorrectly\n");
1644 			return -EINVAL;
1645 		}
1646 		break;
1647 	default:
1648 		dev_err(&pl022->adev->dev,
1649 			"RX FIFO Trigger Level is configured incorrectly\n");
1650 		return -EINVAL;
1651 	}
1652 	switch (chip_info->tx_lev_trig) {
1653 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1654 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1655 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1656 		/* These are always OK, all variants can handle this */
1657 		break;
1658 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1659 		if (pl022->vendor->fifodepth < 16) {
1660 			dev_err(&pl022->adev->dev,
1661 			"TX FIFO Trigger Level is configured incorrectly\n");
1662 			return -EINVAL;
1663 		}
1664 		break;
1665 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1666 		if (pl022->vendor->fifodepth < 32) {
1667 			dev_err(&pl022->adev->dev,
1668 			"TX FIFO Trigger Level is configured incorrectly\n");
1669 			return -EINVAL;
1670 		}
1671 		break;
1672 	default:
1673 		dev_err(&pl022->adev->dev,
1674 			"TX FIFO Trigger Level is configured incorrectly\n");
1675 		return -EINVAL;
1676 	}
1677 	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1678 		if ((chip_info->ctrl_len < SSP_BITS_4)
1679 		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1680 			dev_err(&pl022->adev->dev,
1681 				"CTRL LEN is configured incorrectly\n");
1682 			return -EINVAL;
1683 		}
1684 		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1685 		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1686 			dev_err(&pl022->adev->dev,
1687 				"Wait State is configured incorrectly\n");
1688 			return -EINVAL;
1689 		}
1690 		/* Half duplex is only available in the ST Micro version */
1691 		if (pl022->vendor->extended_cr) {
1692 			if ((chip_info->duplex !=
1693 			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1694 			    && (chip_info->duplex !=
1695 				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1696 				dev_err(&pl022->adev->dev,
1697 					"Microwire duplex mode is configured incorrectly\n");
1698 				return -EINVAL;
1699 			}
1700 		} else {
1701 			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1702 				dev_err(&pl022->adev->dev,
1703 					"Microwire half duplex mode requested,"
1704 					" but this is only available in the"
1705 					" ST version of PL022\n");
1706 			return -EINVAL;
1707 		}
1708 	}
1709 	return 0;
1710 }
1711 
1712 static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1713 {
1714 	return rate / (cpsdvsr * (1 + scr));
1715 }
1716 
1717 static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1718 				    ssp_clock_params * clk_freq)
1719 {
1720 	/* Lets calculate the frequency parameters */
1721 	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1722 	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1723 		best_scr = 0, tmp, found = 0;
1724 
1725 	rate = clk_get_rate(pl022->clk);
1726 	/* cpsdvscr = 2 & scr 0 */
1727 	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1728 	/* cpsdvsr = 254 & scr = 255 */
1729 	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1730 
1731 	if (freq > max_tclk)
1732 		dev_warn(&pl022->adev->dev,
1733 			"Max speed that can be programmed is %d Hz, you requested %d\n",
1734 			max_tclk, freq);
1735 
1736 	if (freq < min_tclk) {
1737 		dev_err(&pl022->adev->dev,
1738 			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1739 			freq, min_tclk);
1740 		return -EINVAL;
1741 	}
1742 
1743 	/*
1744 	 * best_freq will give closest possible available rate (<= requested
1745 	 * freq) for all values of scr & cpsdvsr.
1746 	 */
1747 	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1748 		while (scr <= SCR_MAX) {
1749 			tmp = spi_rate(rate, cpsdvsr, scr);
1750 
1751 			if (tmp > freq) {
1752 				/* we need lower freq */
1753 				scr++;
1754 				continue;
1755 			}
1756 
1757 			/*
1758 			 * If found exact value, mark found and break.
1759 			 * If found more closer value, update and break.
1760 			 */
1761 			if (tmp > best_freq) {
1762 				best_freq = tmp;
1763 				best_cpsdvsr = cpsdvsr;
1764 				best_scr = scr;
1765 
1766 				if (tmp == freq)
1767 					found = 1;
1768 			}
1769 			/*
1770 			 * increased scr will give lower rates, which are not
1771 			 * required
1772 			 */
1773 			break;
1774 		}
1775 		cpsdvsr += 2;
1776 		scr = SCR_MIN;
1777 	}
1778 
1779 	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1780 			freq);
1781 
1782 	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1783 	clk_freq->scr = (u8) (best_scr & 0xFF);
1784 	dev_dbg(&pl022->adev->dev,
1785 		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1786 		freq, best_freq);
1787 	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1788 		clk_freq->cpsdvsr, clk_freq->scr);
1789 
1790 	return 0;
1791 }
1792 
1793 /*
1794  * A piece of default chip info unless the platform
1795  * supplies it.
1796  */
1797 static const struct pl022_config_chip pl022_default_chip_info = {
1798 	.com_mode = POLLING_TRANSFER,
1799 	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1800 	.hierarchy = SSP_SLAVE,
1801 	.slave_tx_disable = DO_NOT_DRIVE_TX,
1802 	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1803 	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1804 	.ctrl_len = SSP_BITS_8,
1805 	.wait_state = SSP_MWIRE_WAIT_ZERO,
1806 	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1807 	.cs_control = null_cs_control,
1808 };
1809 
1810 /**
1811  * pl022_setup - setup function registered to SPI master framework
1812  * @spi: spi device which is requesting setup
1813  *
1814  * This function is registered to the SPI framework for this SPI master
1815  * controller. If it is the first time when setup is called by this device,
1816  * this function will initialize the runtime state for this chip and save
1817  * the same in the device structure. Else it will update the runtime info
1818  * with the updated chip info. Nothing is really being written to the
1819  * controller hardware here, that is not done until the actual transfer
1820  * commence.
1821  */
1822 static int pl022_setup(struct spi_device *spi)
1823 {
1824 	struct pl022_config_chip const *chip_info;
1825 	struct pl022_config_chip chip_info_dt;
1826 	struct chip_data *chip;
1827 	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1828 	int status = 0;
1829 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1830 	unsigned int bits = spi->bits_per_word;
1831 	u32 tmp;
1832 	struct device_node *np = spi->dev.of_node;
1833 
1834 	if (!spi->max_speed_hz)
1835 		return -EINVAL;
1836 
1837 	/* Get controller_state if one is supplied */
1838 	chip = spi_get_ctldata(spi);
1839 
1840 	if (chip == NULL) {
1841 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1842 		if (!chip)
1843 			return -ENOMEM;
1844 		dev_dbg(&spi->dev,
1845 			"allocated memory for controller's runtime state\n");
1846 	}
1847 
1848 	/* Get controller data if one is supplied */
1849 	chip_info = spi->controller_data;
1850 
1851 	if (chip_info == NULL) {
1852 		if (np) {
1853 			chip_info_dt = pl022_default_chip_info;
1854 
1855 			chip_info_dt.hierarchy = SSP_MASTER;
1856 			of_property_read_u32(np, "pl022,interface",
1857 				&chip_info_dt.iface);
1858 			of_property_read_u32(np, "pl022,com-mode",
1859 				&chip_info_dt.com_mode);
1860 			of_property_read_u32(np, "pl022,rx-level-trig",
1861 				&chip_info_dt.rx_lev_trig);
1862 			of_property_read_u32(np, "pl022,tx-level-trig",
1863 				&chip_info_dt.tx_lev_trig);
1864 			of_property_read_u32(np, "pl022,ctrl-len",
1865 				&chip_info_dt.ctrl_len);
1866 			of_property_read_u32(np, "pl022,wait-state",
1867 				&chip_info_dt.wait_state);
1868 			of_property_read_u32(np, "pl022,duplex",
1869 				&chip_info_dt.duplex);
1870 
1871 			chip_info = &chip_info_dt;
1872 		} else {
1873 			chip_info = &pl022_default_chip_info;
1874 			/* spi_board_info.controller_data not is supplied */
1875 			dev_dbg(&spi->dev,
1876 				"using default controller_data settings\n");
1877 		}
1878 	} else
1879 		dev_dbg(&spi->dev,
1880 			"using user supplied controller_data settings\n");
1881 
1882 	/*
1883 	 * We can override with custom divisors, else we use the board
1884 	 * frequency setting
1885 	 */
1886 	if ((0 == chip_info->clk_freq.cpsdvsr)
1887 	    && (0 == chip_info->clk_freq.scr)) {
1888 		status = calculate_effective_freq(pl022,
1889 						  spi->max_speed_hz,
1890 						  &clk_freq);
1891 		if (status < 0)
1892 			goto err_config_params;
1893 	} else {
1894 		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1895 		if ((clk_freq.cpsdvsr % 2) != 0)
1896 			clk_freq.cpsdvsr =
1897 				clk_freq.cpsdvsr - 1;
1898 	}
1899 	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1900 	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1901 		status = -EINVAL;
1902 		dev_err(&spi->dev,
1903 			"cpsdvsr is configured incorrectly\n");
1904 		goto err_config_params;
1905 	}
1906 
1907 	status = verify_controller_parameters(pl022, chip_info);
1908 	if (status) {
1909 		dev_err(&spi->dev, "controller data is incorrect");
1910 		goto err_config_params;
1911 	}
1912 
1913 	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1914 	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1915 
1916 	/* Now set controller state based on controller data */
1917 	chip->xfer_type = chip_info->com_mode;
1918 	if (!chip_info->cs_control) {
1919 		chip->cs_control = null_cs_control;
1920 		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1921 			dev_warn(&spi->dev,
1922 				 "invalid chip select\n");
1923 	} else
1924 		chip->cs_control = chip_info->cs_control;
1925 
1926 	/* Check bits per word with vendor specific range */
1927 	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1928 		status = -ENOTSUPP;
1929 		dev_err(&spi->dev, "illegal data size for this controller!\n");
1930 		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1931 				pl022->vendor->max_bpw);
1932 		goto err_config_params;
1933 	} else if (bits <= 8) {
1934 		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1935 		chip->n_bytes = 1;
1936 		chip->read = READING_U8;
1937 		chip->write = WRITING_U8;
1938 	} else if (bits <= 16) {
1939 		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1940 		chip->n_bytes = 2;
1941 		chip->read = READING_U16;
1942 		chip->write = WRITING_U16;
1943 	} else {
1944 		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1945 		chip->n_bytes = 4;
1946 		chip->read = READING_U32;
1947 		chip->write = WRITING_U32;
1948 	}
1949 
1950 	/* Now Initialize all register settings required for this chip */
1951 	chip->cr0 = 0;
1952 	chip->cr1 = 0;
1953 	chip->dmacr = 0;
1954 	chip->cpsr = 0;
1955 	if ((chip_info->com_mode == DMA_TRANSFER)
1956 	    && ((pl022->master_info)->enable_dma)) {
1957 		chip->enable_dma = true;
1958 		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1959 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1960 			       SSP_DMACR_MASK_RXDMAE, 0);
1961 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1962 			       SSP_DMACR_MASK_TXDMAE, 1);
1963 	} else {
1964 		chip->enable_dma = false;
1965 		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1966 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1967 			       SSP_DMACR_MASK_RXDMAE, 0);
1968 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1969 			       SSP_DMACR_MASK_TXDMAE, 1);
1970 	}
1971 
1972 	chip->cpsr = clk_freq.cpsdvsr;
1973 
1974 	/* Special setup for the ST micro extended control registers */
1975 	if (pl022->vendor->extended_cr) {
1976 		u32 etx;
1977 
1978 		if (pl022->vendor->pl023) {
1979 			/* These bits are only in the PL023 */
1980 			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
1981 				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
1982 		} else {
1983 			/* These bits are in the PL022 but not PL023 */
1984 			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
1985 				       SSP_CR0_MASK_HALFDUP_ST, 5);
1986 			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
1987 				       SSP_CR0_MASK_CSS_ST, 16);
1988 			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1989 				       SSP_CR0_MASK_FRF_ST, 21);
1990 			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
1991 				       SSP_CR1_MASK_MWAIT_ST, 6);
1992 		}
1993 		SSP_WRITE_BITS(chip->cr0, bits - 1,
1994 			       SSP_CR0_MASK_DSS_ST, 0);
1995 
1996 		if (spi->mode & SPI_LSB_FIRST) {
1997 			tmp = SSP_RX_LSB;
1998 			etx = SSP_TX_LSB;
1999 		} else {
2000 			tmp = SSP_RX_MSB;
2001 			etx = SSP_TX_MSB;
2002 		}
2003 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
2004 		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
2005 		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
2006 			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
2007 		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
2008 			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
2009 	} else {
2010 		SSP_WRITE_BITS(chip->cr0, bits - 1,
2011 			       SSP_CR0_MASK_DSS, 0);
2012 		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2013 			       SSP_CR0_MASK_FRF, 4);
2014 	}
2015 
2016 	/* Stuff that is common for all versions */
2017 	if (spi->mode & SPI_CPOL)
2018 		tmp = SSP_CLK_POL_IDLE_HIGH;
2019 	else
2020 		tmp = SSP_CLK_POL_IDLE_LOW;
2021 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
2022 
2023 	if (spi->mode & SPI_CPHA)
2024 		tmp = SSP_CLK_SECOND_EDGE;
2025 	else
2026 		tmp = SSP_CLK_FIRST_EDGE;
2027 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
2028 
2029 	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
2030 	/* Loopback is available on all versions except PL023 */
2031 	if (pl022->vendor->loopback) {
2032 		if (spi->mode & SPI_LOOP)
2033 			tmp = LOOPBACK_ENABLED;
2034 		else
2035 			tmp = LOOPBACK_DISABLED;
2036 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2037 	}
2038 	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2039 	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2040 	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2041 		3);
2042 
2043 	/* Save controller_state */
2044 	spi_set_ctldata(spi, chip);
2045 	return status;
2046  err_config_params:
2047 	spi_set_ctldata(spi, NULL);
2048 	kfree(chip);
2049 	return status;
2050 }
2051 
2052 /**
2053  * pl022_cleanup - cleanup function registered to SPI master framework
2054  * @spi: spi device which is requesting cleanup
2055  *
2056  * This function is registered to the SPI framework for this SPI master
2057  * controller. It will free the runtime state of chip.
2058  */
2059 static void pl022_cleanup(struct spi_device *spi)
2060 {
2061 	struct chip_data *chip = spi_get_ctldata(spi);
2062 
2063 	spi_set_ctldata(spi, NULL);
2064 	kfree(chip);
2065 }
2066 
2067 static struct pl022_ssp_controller *
2068 pl022_platform_data_dt_get(struct device *dev)
2069 {
2070 	struct device_node *np = dev->of_node;
2071 	struct pl022_ssp_controller *pd;
2072 	u32 tmp;
2073 
2074 	if (!np) {
2075 		dev_err(dev, "no dt node defined\n");
2076 		return NULL;
2077 	}
2078 
2079 	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2080 	if (!pd)
2081 		return NULL;
2082 
2083 	pd->bus_id = -1;
2084 	pd->enable_dma = 1;
2085 	of_property_read_u32(np, "num-cs", &tmp);
2086 	pd->num_chipselect = tmp;
2087 	of_property_read_u32(np, "pl022,autosuspend-delay",
2088 			     &pd->autosuspend_delay);
2089 	pd->rt = of_property_read_bool(np, "pl022,rt");
2090 
2091 	return pd;
2092 }
2093 
2094 static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2095 {
2096 	struct device *dev = &adev->dev;
2097 	struct pl022_ssp_controller *platform_info =
2098 			dev_get_platdata(&adev->dev);
2099 	struct spi_master *master;
2100 	struct pl022 *pl022 = NULL;	/*Data for this driver */
2101 	struct device_node *np = adev->dev.of_node;
2102 	int status = 0, i, num_cs;
2103 
2104 	dev_info(&adev->dev,
2105 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2106 	if (!platform_info && IS_ENABLED(CONFIG_OF))
2107 		platform_info = pl022_platform_data_dt_get(dev);
2108 
2109 	if (!platform_info) {
2110 		dev_err(dev, "probe: no platform data defined\n");
2111 		return -ENODEV;
2112 	}
2113 
2114 	if (platform_info->num_chipselect) {
2115 		num_cs = platform_info->num_chipselect;
2116 	} else {
2117 		dev_err(dev, "probe: no chip select defined\n");
2118 		return -ENODEV;
2119 	}
2120 
2121 	/* Allocate master with space for data */
2122 	master = spi_alloc_master(dev, sizeof(struct pl022));
2123 	if (master == NULL) {
2124 		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2125 		return -ENOMEM;
2126 	}
2127 
2128 	pl022 = spi_master_get_devdata(master);
2129 	pl022->master = master;
2130 	pl022->master_info = platform_info;
2131 	pl022->adev = adev;
2132 	pl022->vendor = id->data;
2133 	pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
2134 					  GFP_KERNEL);
2135 	if (!pl022->chipselects) {
2136 		status = -ENOMEM;
2137 		goto err_no_mem;
2138 	}
2139 
2140 	/*
2141 	 * Bus Number Which has been Assigned to this SSP controller
2142 	 * on this board
2143 	 */
2144 	master->bus_num = platform_info->bus_id;
2145 	master->num_chipselect = num_cs;
2146 	master->cleanup = pl022_cleanup;
2147 	master->setup = pl022_setup;
2148 	master->auto_runtime_pm = true;
2149 	master->transfer_one_message = pl022_transfer_one_message;
2150 	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2151 	master->rt = platform_info->rt;
2152 	master->dev.of_node = dev->of_node;
2153 
2154 	if (platform_info->num_chipselect && platform_info->chipselects) {
2155 		for (i = 0; i < num_cs; i++)
2156 			pl022->chipselects[i] = platform_info->chipselects[i];
2157 	} else if (pl022->vendor->internal_cs_ctrl) {
2158 		for (i = 0; i < num_cs; i++)
2159 			pl022->chipselects[i] = i;
2160 	} else if (IS_ENABLED(CONFIG_OF)) {
2161 		for (i = 0; i < num_cs; i++) {
2162 			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2163 
2164 			if (cs_gpio == -EPROBE_DEFER) {
2165 				status = -EPROBE_DEFER;
2166 				goto err_no_gpio;
2167 			}
2168 
2169 			pl022->chipselects[i] = cs_gpio;
2170 
2171 			if (gpio_is_valid(cs_gpio)) {
2172 				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2173 					dev_err(&adev->dev,
2174 						"could not request %d gpio\n",
2175 						cs_gpio);
2176 				else if (gpio_direction_output(cs_gpio, 1))
2177 					dev_err(&adev->dev,
2178 						"could not set gpio %d as output\n",
2179 						cs_gpio);
2180 			}
2181 		}
2182 	}
2183 
2184 	/*
2185 	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2186 	 * always MS bit first on the original pl022.
2187 	 */
2188 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2189 	if (pl022->vendor->extended_cr)
2190 		master->mode_bits |= SPI_LSB_FIRST;
2191 
2192 	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2193 
2194 	status = amba_request_regions(adev, NULL);
2195 	if (status)
2196 		goto err_no_ioregion;
2197 
2198 	pl022->phybase = adev->res.start;
2199 	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2200 				       resource_size(&adev->res));
2201 	if (pl022->virtbase == NULL) {
2202 		status = -ENOMEM;
2203 		goto err_no_ioremap;
2204 	}
2205 	dev_info(&adev->dev, "mapped registers from %pa to %p\n",
2206 		&adev->res.start, pl022->virtbase);
2207 
2208 	pl022->clk = devm_clk_get(&adev->dev, NULL);
2209 	if (IS_ERR(pl022->clk)) {
2210 		status = PTR_ERR(pl022->clk);
2211 		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2212 		goto err_no_clk;
2213 	}
2214 
2215 	status = clk_prepare_enable(pl022->clk);
2216 	if (status) {
2217 		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2218 		goto err_no_clk_en;
2219 	}
2220 
2221 	/* Initialize transfer pump */
2222 	tasklet_init(&pl022->pump_transfers, pump_transfers,
2223 		     (unsigned long)pl022);
2224 
2225 	/* Disable SSP */
2226 	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2227 	       SSP_CR1(pl022->virtbase));
2228 	load_ssp_default_config(pl022);
2229 
2230 	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2231 				  0, "pl022", pl022);
2232 	if (status < 0) {
2233 		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2234 		goto err_no_irq;
2235 	}
2236 
2237 	/* Get DMA channels, try autoconfiguration first */
2238 	status = pl022_dma_autoprobe(pl022);
2239 
2240 	/* If that failed, use channels from platform_info */
2241 	if (status == 0)
2242 		platform_info->enable_dma = 1;
2243 	else if (platform_info->enable_dma) {
2244 		status = pl022_dma_probe(pl022);
2245 		if (status != 0)
2246 			platform_info->enable_dma = 0;
2247 	}
2248 
2249 	/* Register with the SPI framework */
2250 	amba_set_drvdata(adev, pl022);
2251 	status = devm_spi_register_master(&adev->dev, master);
2252 	if (status != 0) {
2253 		dev_err(&adev->dev,
2254 			"probe - problem registering spi master\n");
2255 		goto err_spi_register;
2256 	}
2257 	dev_dbg(dev, "probe succeeded\n");
2258 
2259 	/* let runtime pm put suspend */
2260 	if (platform_info->autosuspend_delay > 0) {
2261 		dev_info(&adev->dev,
2262 			"will use autosuspend for runtime pm, delay %dms\n",
2263 			platform_info->autosuspend_delay);
2264 		pm_runtime_set_autosuspend_delay(dev,
2265 			platform_info->autosuspend_delay);
2266 		pm_runtime_use_autosuspend(dev);
2267 	}
2268 	pm_runtime_put(dev);
2269 
2270 	return 0;
2271 
2272  err_spi_register:
2273 	if (platform_info->enable_dma)
2274 		pl022_dma_remove(pl022);
2275  err_no_irq:
2276 	clk_disable_unprepare(pl022->clk);
2277  err_no_clk_en:
2278  err_no_clk:
2279  err_no_ioremap:
2280 	amba_release_regions(adev);
2281  err_no_ioregion:
2282  err_no_gpio:
2283  err_no_mem:
2284 	spi_master_put(master);
2285 	return status;
2286 }
2287 
2288 static int
2289 pl022_remove(struct amba_device *adev)
2290 {
2291 	struct pl022 *pl022 = amba_get_drvdata(adev);
2292 
2293 	if (!pl022)
2294 		return 0;
2295 
2296 	/*
2297 	 * undo pm_runtime_put() in probe.  I assume that we're not
2298 	 * accessing the primecell here.
2299 	 */
2300 	pm_runtime_get_noresume(&adev->dev);
2301 
2302 	load_ssp_default_config(pl022);
2303 	if (pl022->master_info->enable_dma)
2304 		pl022_dma_remove(pl022);
2305 
2306 	clk_disable_unprepare(pl022->clk);
2307 	amba_release_regions(adev);
2308 	tasklet_disable(&pl022->pump_transfers);
2309 	return 0;
2310 }
2311 
2312 #ifdef CONFIG_PM_SLEEP
2313 static int pl022_suspend(struct device *dev)
2314 {
2315 	struct pl022 *pl022 = dev_get_drvdata(dev);
2316 	int ret;
2317 
2318 	ret = spi_master_suspend(pl022->master);
2319 	if (ret) {
2320 		dev_warn(dev, "cannot suspend master\n");
2321 		return ret;
2322 	}
2323 
2324 	ret = pm_runtime_force_suspend(dev);
2325 	if (ret) {
2326 		spi_master_resume(pl022->master);
2327 		return ret;
2328 	}
2329 
2330 	pinctrl_pm_select_sleep_state(dev);
2331 
2332 	dev_dbg(dev, "suspended\n");
2333 	return 0;
2334 }
2335 
2336 static int pl022_resume(struct device *dev)
2337 {
2338 	struct pl022 *pl022 = dev_get_drvdata(dev);
2339 	int ret;
2340 
2341 	ret = pm_runtime_force_resume(dev);
2342 	if (ret)
2343 		dev_err(dev, "problem resuming\n");
2344 
2345 	/* Start the queue running */
2346 	ret = spi_master_resume(pl022->master);
2347 	if (ret)
2348 		dev_err(dev, "problem starting queue (%d)\n", ret);
2349 	else
2350 		dev_dbg(dev, "resumed\n");
2351 
2352 	return ret;
2353 }
2354 #endif
2355 
2356 #ifdef CONFIG_PM
2357 static int pl022_runtime_suspend(struct device *dev)
2358 {
2359 	struct pl022 *pl022 = dev_get_drvdata(dev);
2360 
2361 	clk_disable_unprepare(pl022->clk);
2362 	pinctrl_pm_select_idle_state(dev);
2363 
2364 	return 0;
2365 }
2366 
2367 static int pl022_runtime_resume(struct device *dev)
2368 {
2369 	struct pl022 *pl022 = dev_get_drvdata(dev);
2370 
2371 	pinctrl_pm_select_default_state(dev);
2372 	clk_prepare_enable(pl022->clk);
2373 
2374 	return 0;
2375 }
2376 #endif
2377 
2378 static const struct dev_pm_ops pl022_dev_pm_ops = {
2379 	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2380 	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2381 };
2382 
2383 static struct vendor_data vendor_arm = {
2384 	.fifodepth = 8,
2385 	.max_bpw = 16,
2386 	.unidir = false,
2387 	.extended_cr = false,
2388 	.pl023 = false,
2389 	.loopback = true,
2390 	.internal_cs_ctrl = false,
2391 };
2392 
2393 static struct vendor_data vendor_st = {
2394 	.fifodepth = 32,
2395 	.max_bpw = 32,
2396 	.unidir = false,
2397 	.extended_cr = true,
2398 	.pl023 = false,
2399 	.loopback = true,
2400 	.internal_cs_ctrl = false,
2401 };
2402 
2403 static struct vendor_data vendor_st_pl023 = {
2404 	.fifodepth = 32,
2405 	.max_bpw = 32,
2406 	.unidir = false,
2407 	.extended_cr = true,
2408 	.pl023 = true,
2409 	.loopback = false,
2410 	.internal_cs_ctrl = false,
2411 };
2412 
2413 static struct vendor_data vendor_lsi = {
2414 	.fifodepth = 8,
2415 	.max_bpw = 16,
2416 	.unidir = false,
2417 	.extended_cr = false,
2418 	.pl023 = false,
2419 	.loopback = true,
2420 	.internal_cs_ctrl = true,
2421 };
2422 
2423 static struct amba_id pl022_ids[] = {
2424 	{
2425 		/*
2426 		 * ARM PL022 variant, this has a 16bit wide
2427 		 * and 8 locations deep TX/RX FIFO
2428 		 */
2429 		.id	= 0x00041022,
2430 		.mask	= 0x000fffff,
2431 		.data	= &vendor_arm,
2432 	},
2433 	{
2434 		/*
2435 		 * ST Micro derivative, this has 32bit wide
2436 		 * and 32 locations deep TX/RX FIFO
2437 		 */
2438 		.id	= 0x01080022,
2439 		.mask	= 0xffffffff,
2440 		.data	= &vendor_st,
2441 	},
2442 	{
2443 		/*
2444 		 * ST-Ericsson derivative "PL023" (this is not
2445 		 * an official ARM number), this is a PL022 SSP block
2446 		 * stripped to SPI mode only, it has 32bit wide
2447 		 * and 32 locations deep TX/RX FIFO but no extended
2448 		 * CR0/CR1 register
2449 		 */
2450 		.id	= 0x00080023,
2451 		.mask	= 0xffffffff,
2452 		.data	= &vendor_st_pl023,
2453 	},
2454 	{
2455 		/*
2456 		 * PL022 variant that has a chip select control register whih
2457 		 * allows control of 5 output signals nCS[0:4].
2458 		 */
2459 		.id	= 0x000b6022,
2460 		.mask	= 0x000fffff,
2461 		.data	= &vendor_lsi,
2462 	},
2463 	{ 0, 0 },
2464 };
2465 
2466 MODULE_DEVICE_TABLE(amba, pl022_ids);
2467 
2468 static struct amba_driver pl022_driver = {
2469 	.drv = {
2470 		.name	= "ssp-pl022",
2471 		.pm	= &pl022_dev_pm_ops,
2472 	},
2473 	.id_table	= pl022_ids,
2474 	.probe		= pl022_probe,
2475 	.remove		= pl022_remove,
2476 };
2477 
2478 static int __init pl022_init(void)
2479 {
2480 	return amba_driver_register(&pl022_driver);
2481 }
2482 subsys_initcall(pl022_init);
2483 
2484 static void __exit pl022_exit(void)
2485 {
2486 	amba_driver_unregister(&pl022_driver);
2487 }
2488 module_exit(pl022_exit);
2489 
2490 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2491 MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2492 MODULE_LICENSE("GPL");
2493