xref: /openbmc/linux/drivers/spi/spi-pl022.c (revision fd4a319b)
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_ITCR(r)	(r + 0x080)
86 #define SSP_ITIP(r)	(r + 0x084)
87 #define SSP_ITOP(r)	(r + 0x088)
88 #define SSP_TDR(r)	(r + 0x08C)
89 
90 #define SSP_PID0(r)	(r + 0xFE0)
91 #define SSP_PID1(r)	(r + 0xFE4)
92 #define SSP_PID2(r)	(r + 0xFE8)
93 #define SSP_PID3(r)	(r + 0xFEC)
94 
95 #define SSP_CID0(r)	(r + 0xFF0)
96 #define SSP_CID1(r)	(r + 0xFF4)
97 #define SSP_CID2(r)	(r + 0xFF8)
98 #define SSP_CID3(r)	(r + 0xFFC)
99 
100 /*
101  * SSP Control Register 0  - SSP_CR0
102  */
103 #define SSP_CR0_MASK_DSS	(0x0FUL << 0)
104 #define SSP_CR0_MASK_FRF	(0x3UL << 4)
105 #define SSP_CR0_MASK_SPO	(0x1UL << 6)
106 #define SSP_CR0_MASK_SPH	(0x1UL << 7)
107 #define SSP_CR0_MASK_SCR	(0xFFUL << 8)
108 
109 /*
110  * The ST version of this block moves som bits
111  * in SSP_CR0 and extends it to 32 bits
112  */
113 #define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
114 #define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
115 #define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
116 #define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
117 
118 /*
119  * SSP Control Register 0  - SSP_CR1
120  */
121 #define SSP_CR1_MASK_LBM	(0x1UL << 0)
122 #define SSP_CR1_MASK_SSE	(0x1UL << 1)
123 #define SSP_CR1_MASK_MS		(0x1UL << 2)
124 #define SSP_CR1_MASK_SOD	(0x1UL << 3)
125 
126 /*
127  * The ST version of this block adds some bits
128  * in SSP_CR1
129  */
130 #define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
131 #define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
132 #define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
133 #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
134 #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
135 /* This one is only in the PL023 variant */
136 #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
137 
138 /*
139  * SSP Status Register - SSP_SR
140  */
141 #define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
142 #define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
143 #define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
144 #define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
145 #define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
146 
147 /*
148  * SSP Clock Prescale Register  - SSP_CPSR
149  */
150 #define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
151 
152 /*
153  * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
154  */
155 #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
156 #define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
157 #define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
158 #define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
159 
160 /*
161  * SSP Raw Interrupt Status Register - SSP_RIS
162  */
163 /* Receive Overrun Raw Interrupt status */
164 #define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
165 /* Receive Timeout Raw Interrupt status */
166 #define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
167 /* Receive FIFO Raw Interrupt status */
168 #define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
169 /* Transmit FIFO Raw Interrupt status */
170 #define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
171 
172 /*
173  * SSP Masked Interrupt Status Register - SSP_MIS
174  */
175 /* Receive Overrun Masked Interrupt status */
176 #define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
177 /* Receive Timeout Masked Interrupt status */
178 #define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
179 /* Receive FIFO Masked Interrupt status */
180 #define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
181 /* Transmit FIFO Masked Interrupt status */
182 #define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
183 
184 /*
185  * SSP Interrupt Clear Register - SSP_ICR
186  */
187 /* Receive Overrun Raw Clear Interrupt bit */
188 #define SSP_ICR_MASK_RORIC		(0x1UL << 0)
189 /* Receive Timeout Clear Interrupt bit */
190 #define SSP_ICR_MASK_RTIC		(0x1UL << 1)
191 
192 /*
193  * SSP DMA Control Register - SSP_DMACR
194  */
195 /* Receive DMA Enable bit */
196 #define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
197 /* Transmit DMA Enable bit */
198 #define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
199 
200 /*
201  * SSP Integration Test control Register - SSP_ITCR
202  */
203 #define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
204 #define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
205 
206 /*
207  * SSP Integration Test Input Register - SSP_ITIP
208  */
209 #define ITIP_MASK_SSPRXD		 (0x1UL << 0)
210 #define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
211 #define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
212 #define ITIP_MASK_RXDMAC		 (0x1UL << 3)
213 #define ITIP_MASK_TXDMAC		 (0x1UL << 4)
214 #define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
215 
216 /*
217  * SSP Integration Test output Register - SSP_ITOP
218  */
219 #define ITOP_MASK_SSPTXD		 (0x1UL << 0)
220 #define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
221 #define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
222 #define ITOP_MASK_SSPOEn		 (0x1UL << 3)
223 #define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
224 #define ITOP_MASK_RORINTR		 (0x1UL << 5)
225 #define ITOP_MASK_RTINTR		 (0x1UL << 6)
226 #define ITOP_MASK_RXINTR		 (0x1UL << 7)
227 #define ITOP_MASK_TXINTR		 (0x1UL << 8)
228 #define ITOP_MASK_INTR			 (0x1UL << 9)
229 #define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
230 #define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
231 #define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
232 #define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
233 
234 /*
235  * SSP Test Data Register - SSP_TDR
236  */
237 #define TDR_MASK_TESTDATA		(0xFFFFFFFF)
238 
239 /*
240  * Message State
241  * we use the spi_message.state (void *) pointer to
242  * hold a single state value, that's why all this
243  * (void *) casting is done here.
244  */
245 #define STATE_START			((void *) 0)
246 #define STATE_RUNNING			((void *) 1)
247 #define STATE_DONE			((void *) 2)
248 #define STATE_ERROR			((void *) -1)
249 
250 /*
251  * SSP State - Whether Enabled or Disabled
252  */
253 #define SSP_DISABLED			(0)
254 #define SSP_ENABLED			(1)
255 
256 /*
257  * SSP DMA State - Whether DMA Enabled or Disabled
258  */
259 #define SSP_DMA_DISABLED		(0)
260 #define SSP_DMA_ENABLED			(1)
261 
262 /*
263  * SSP Clock Defaults
264  */
265 #define SSP_DEFAULT_CLKRATE 0x2
266 #define SSP_DEFAULT_PRESCALE 0x40
267 
268 /*
269  * SSP Clock Parameter ranges
270  */
271 #define CPSDVR_MIN 0x02
272 #define CPSDVR_MAX 0xFE
273 #define SCR_MIN 0x00
274 #define SCR_MAX 0xFF
275 
276 /*
277  * SSP Interrupt related Macros
278  */
279 #define DEFAULT_SSP_REG_IMSC  0x0UL
280 #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
281 #define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
282 
283 #define CLEAR_ALL_INTERRUPTS  0x3
284 
285 #define SPI_POLLING_TIMEOUT 1000
286 
287 /*
288  * The type of reading going on on this chip
289  */
290 enum ssp_reading {
291 	READING_NULL,
292 	READING_U8,
293 	READING_U16,
294 	READING_U32
295 };
296 
297 /**
298  * The type of writing going on on this chip
299  */
300 enum ssp_writing {
301 	WRITING_NULL,
302 	WRITING_U8,
303 	WRITING_U16,
304 	WRITING_U32
305 };
306 
307 /**
308  * struct vendor_data - vendor-specific config parameters
309  * for PL022 derivates
310  * @fifodepth: depth of FIFOs (both)
311  * @max_bpw: maximum number of bits per word
312  * @unidir: supports unidirection transfers
313  * @extended_cr: 32 bit wide control register 0 with extra
314  * features and extra features in CR1 as found in the ST variants
315  * @pl023: supports a subset of the ST extensions called "PL023"
316  */
317 struct vendor_data {
318 	int fifodepth;
319 	int max_bpw;
320 	bool unidir;
321 	bool extended_cr;
322 	bool pl023;
323 	bool loopback;
324 };
325 
326 /**
327  * struct pl022 - This is the private SSP driver data structure
328  * @adev: AMBA device model hookup
329  * @vendor: vendor data for the IP block
330  * @phybase: the physical memory where the SSP device resides
331  * @virtbase: the virtual memory where the SSP is mapped
332  * @clk: outgoing clock "SPICLK" for the SPI bus
333  * @master: SPI framework hookup
334  * @master_info: controller-specific data from machine setup
335  * @kworker: thread struct for message pump
336  * @kworker_task: pointer to task for message pump kworker thread
337  * @pump_messages: work struct for scheduling work to the message pump
338  * @queue_lock: spinlock to syncronise access to message queue
339  * @queue: message queue
340  * @busy: message pump is busy
341  * @running: message pump is running
342  * @pump_transfers: Tasklet used in Interrupt Transfer mode
343  * @cur_msg: Pointer to current spi_message being processed
344  * @cur_transfer: Pointer to current spi_transfer
345  * @cur_chip: pointer to current clients chip(assigned from controller_state)
346  * @next_msg_cs_active: the next message in the queue has been examined
347  *  and it was found that it uses the same chip select as the previous
348  *  message, so we left it active after the previous transfer, and it's
349  *  active already.
350  * @tx: current position in TX buffer to be read
351  * @tx_end: end position in TX buffer to be read
352  * @rx: current position in RX buffer to be written
353  * @rx_end: end position in RX buffer to be written
354  * @read: the type of read currently going on
355  * @write: the type of write currently going on
356  * @exp_fifo_level: expected FIFO level
357  * @dma_rx_channel: optional channel for RX DMA
358  * @dma_tx_channel: optional channel for TX DMA
359  * @sgt_rx: scattertable for the RX transfer
360  * @sgt_tx: scattertable for the TX transfer
361  * @dummypage: a dummy page used for driving data on the bus with DMA
362  * @cur_cs: current chip select (gpio)
363  * @chipselects: list of chipselects (gpios)
364  */
365 struct pl022 {
366 	struct amba_device		*adev;
367 	struct vendor_data		*vendor;
368 	resource_size_t			phybase;
369 	void __iomem			*virtbase;
370 	struct clk			*clk;
371 	/* Two optional pin states - default & sleep */
372 	struct pinctrl			*pinctrl;
373 	struct pinctrl_state		*pins_default;
374 	struct pinctrl_state		*pins_idle;
375 	struct pinctrl_state		*pins_sleep;
376 	struct spi_master		*master;
377 	struct pl022_ssp_controller	*master_info;
378 	/* Message per-transfer pump */
379 	struct tasklet_struct		pump_transfers;
380 	struct spi_message		*cur_msg;
381 	struct spi_transfer		*cur_transfer;
382 	struct chip_data		*cur_chip;
383 	bool				next_msg_cs_active;
384 	void				*tx;
385 	void				*tx_end;
386 	void				*rx;
387 	void				*rx_end;
388 	enum ssp_reading		read;
389 	enum ssp_writing		write;
390 	u32				exp_fifo_level;
391 	enum ssp_rx_level_trig		rx_lev_trig;
392 	enum ssp_tx_level_trig		tx_lev_trig;
393 	/* DMA settings */
394 #ifdef CONFIG_DMA_ENGINE
395 	struct dma_chan			*dma_rx_channel;
396 	struct dma_chan			*dma_tx_channel;
397 	struct sg_table			sgt_rx;
398 	struct sg_table			sgt_tx;
399 	char				*dummypage;
400 	bool				dma_running;
401 #endif
402 	int cur_cs;
403 	int *chipselects;
404 };
405 
406 /**
407  * struct chip_data - To maintain runtime state of SSP for each client chip
408  * @cr0: Value of control register CR0 of SSP - on later ST variants this
409  *       register is 32 bits wide rather than just 16
410  * @cr1: Value of control register CR1 of SSP
411  * @dmacr: Value of DMA control Register of SSP
412  * @cpsr: Value of Clock prescale register
413  * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
414  * @enable_dma: Whether to enable DMA or not
415  * @read: function ptr to be used to read when doing xfer for this chip
416  * @write: function ptr to be used to write when doing xfer for this chip
417  * @cs_control: chip select callback provided by chip
418  * @xfer_type: polling/interrupt/DMA
419  *
420  * Runtime state of the SSP controller, maintained per chip,
421  * This would be set according to the current message that would be served
422  */
423 struct chip_data {
424 	u32 cr0;
425 	u16 cr1;
426 	u16 dmacr;
427 	u16 cpsr;
428 	u8 n_bytes;
429 	bool enable_dma;
430 	enum ssp_reading read;
431 	enum ssp_writing write;
432 	void (*cs_control) (u32 command);
433 	int xfer_type;
434 };
435 
436 /**
437  * null_cs_control - Dummy chip select function
438  * @command: select/delect the chip
439  *
440  * If no chip select function is provided by client this is used as dummy
441  * chip select
442  */
443 static void null_cs_control(u32 command)
444 {
445 	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
446 }
447 
448 static void pl022_cs_control(struct pl022 *pl022, u32 command)
449 {
450 	if (gpio_is_valid(pl022->cur_cs))
451 		gpio_set_value(pl022->cur_cs, command);
452 	else
453 		pl022->cur_chip->cs_control(command);
454 }
455 
456 /**
457  * giveback - current spi_message is over, schedule next message and call
458  * callback of this message. Assumes that caller already
459  * set message->status; dma and pio irqs are blocked
460  * @pl022: SSP driver private data structure
461  */
462 static void giveback(struct pl022 *pl022)
463 {
464 	struct spi_transfer *last_transfer;
465 	pl022->next_msg_cs_active = false;
466 
467 	last_transfer = list_entry(pl022->cur_msg->transfers.prev,
468 					struct spi_transfer,
469 					transfer_list);
470 
471 	/* Delay if requested before any change in chip select */
472 	if (last_transfer->delay_usecs)
473 		/*
474 		 * FIXME: This runs in interrupt context.
475 		 * Is this really smart?
476 		 */
477 		udelay(last_transfer->delay_usecs);
478 
479 	if (!last_transfer->cs_change) {
480 		struct spi_message *next_msg;
481 
482 		/*
483 		 * cs_change was not set. We can keep the chip select
484 		 * enabled if there is message in the queue and it is
485 		 * for the same spi device.
486 		 *
487 		 * We cannot postpone this until pump_messages, because
488 		 * after calling msg->complete (below) the driver that
489 		 * sent the current message could be unloaded, which
490 		 * could invalidate the cs_control() callback...
491 		 */
492 		/* get a pointer to the next message, if any */
493 		next_msg = spi_get_next_queued_message(pl022->master);
494 
495 		/*
496 		 * see if the next and current messages point
497 		 * to the same spi device.
498 		 */
499 		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
500 			next_msg = NULL;
501 		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
502 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
503 		else
504 			pl022->next_msg_cs_active = true;
505 
506 	}
507 
508 	pl022->cur_msg = NULL;
509 	pl022->cur_transfer = NULL;
510 	pl022->cur_chip = NULL;
511 	spi_finalize_current_message(pl022->master);
512 
513 	/* disable the SPI/SSP operation */
514 	writew((readw(SSP_CR1(pl022->virtbase)) &
515 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
516 
517 }
518 
519 /**
520  * flush - flush the FIFO to reach a clean state
521  * @pl022: SSP driver private data structure
522  */
523 static int flush(struct pl022 *pl022)
524 {
525 	unsigned long limit = loops_per_jiffy << 1;
526 
527 	dev_dbg(&pl022->adev->dev, "flush\n");
528 	do {
529 		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
530 			readw(SSP_DR(pl022->virtbase));
531 	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
532 
533 	pl022->exp_fifo_level = 0;
534 
535 	return limit;
536 }
537 
538 /**
539  * restore_state - Load configuration of current chip
540  * @pl022: SSP driver private data structure
541  */
542 static void restore_state(struct pl022 *pl022)
543 {
544 	struct chip_data *chip = pl022->cur_chip;
545 
546 	if (pl022->vendor->extended_cr)
547 		writel(chip->cr0, SSP_CR0(pl022->virtbase));
548 	else
549 		writew(chip->cr0, SSP_CR0(pl022->virtbase));
550 	writew(chip->cr1, SSP_CR1(pl022->virtbase));
551 	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
552 	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
553 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
554 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
555 }
556 
557 /*
558  * Default SSP Register Values
559  */
560 #define DEFAULT_SSP_REG_CR0 ( \
561 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
562 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
563 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
564 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
565 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
566 )
567 
568 /* ST versions have slightly different bit layout */
569 #define DEFAULT_SSP_REG_CR0_ST ( \
570 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
571 	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
572 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
573 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
574 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
575 	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
576 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
577 )
578 
579 /* The PL023 version is slightly different again */
580 #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
581 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
582 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
583 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
584 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
585 )
586 
587 #define DEFAULT_SSP_REG_CR1 ( \
588 	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
589 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
590 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
591 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
592 )
593 
594 /* ST versions extend this register to use all 16 bits */
595 #define DEFAULT_SSP_REG_CR1_ST ( \
596 	DEFAULT_SSP_REG_CR1 | \
597 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
598 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
599 	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
600 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
601 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
602 )
603 
604 /*
605  * The PL023 variant has further differences: no loopback mode, no microwire
606  * support, and a new clock feedback delay setting.
607  */
608 #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
609 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
610 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
611 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
612 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
613 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
614 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
615 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
616 	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
617 )
618 
619 #define DEFAULT_SSP_REG_CPSR ( \
620 	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
621 )
622 
623 #define DEFAULT_SSP_REG_DMACR (\
624 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
625 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
626 )
627 
628 /**
629  * load_ssp_default_config - Load default configuration for SSP
630  * @pl022: SSP driver private data structure
631  */
632 static void load_ssp_default_config(struct pl022 *pl022)
633 {
634 	if (pl022->vendor->pl023) {
635 		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
636 		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
637 	} else if (pl022->vendor->extended_cr) {
638 		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
639 		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
640 	} else {
641 		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
642 		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
643 	}
644 	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
645 	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
646 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
647 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
648 }
649 
650 /**
651  * This will write to TX and read from RX according to the parameters
652  * set in pl022.
653  */
654 static void readwriter(struct pl022 *pl022)
655 {
656 
657 	/*
658 	 * The FIFO depth is different between primecell variants.
659 	 * I believe filling in too much in the FIFO might cause
660 	 * errons in 8bit wide transfers on ARM variants (just 8 words
661 	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
662 	 *
663 	 * To prevent this issue, the TX FIFO is only filled to the
664 	 * unused RX FIFO fill length, regardless of what the TX
665 	 * FIFO status flag indicates.
666 	 */
667 	dev_dbg(&pl022->adev->dev,
668 		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
669 		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
670 
671 	/* Read as much as you can */
672 	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
673 	       && (pl022->rx < pl022->rx_end)) {
674 		switch (pl022->read) {
675 		case READING_NULL:
676 			readw(SSP_DR(pl022->virtbase));
677 			break;
678 		case READING_U8:
679 			*(u8 *) (pl022->rx) =
680 				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
681 			break;
682 		case READING_U16:
683 			*(u16 *) (pl022->rx) =
684 				(u16) readw(SSP_DR(pl022->virtbase));
685 			break;
686 		case READING_U32:
687 			*(u32 *) (pl022->rx) =
688 				readl(SSP_DR(pl022->virtbase));
689 			break;
690 		}
691 		pl022->rx += (pl022->cur_chip->n_bytes);
692 		pl022->exp_fifo_level--;
693 	}
694 	/*
695 	 * Write as much as possible up to the RX FIFO size
696 	 */
697 	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
698 	       && (pl022->tx < pl022->tx_end)) {
699 		switch (pl022->write) {
700 		case WRITING_NULL:
701 			writew(0x0, SSP_DR(pl022->virtbase));
702 			break;
703 		case WRITING_U8:
704 			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
705 			break;
706 		case WRITING_U16:
707 			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
708 			break;
709 		case WRITING_U32:
710 			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
711 			break;
712 		}
713 		pl022->tx += (pl022->cur_chip->n_bytes);
714 		pl022->exp_fifo_level++;
715 		/*
716 		 * This inner reader takes care of things appearing in the RX
717 		 * FIFO as we're transmitting. This will happen a lot since the
718 		 * clock starts running when you put things into the TX FIFO,
719 		 * and then things are continuously clocked into the RX FIFO.
720 		 */
721 		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
722 		       && (pl022->rx < pl022->rx_end)) {
723 			switch (pl022->read) {
724 			case READING_NULL:
725 				readw(SSP_DR(pl022->virtbase));
726 				break;
727 			case READING_U8:
728 				*(u8 *) (pl022->rx) =
729 					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
730 				break;
731 			case READING_U16:
732 				*(u16 *) (pl022->rx) =
733 					(u16) readw(SSP_DR(pl022->virtbase));
734 				break;
735 			case READING_U32:
736 				*(u32 *) (pl022->rx) =
737 					readl(SSP_DR(pl022->virtbase));
738 				break;
739 			}
740 			pl022->rx += (pl022->cur_chip->n_bytes);
741 			pl022->exp_fifo_level--;
742 		}
743 	}
744 	/*
745 	 * When we exit here the TX FIFO should be full and the RX FIFO
746 	 * should be empty
747 	 */
748 }
749 
750 /**
751  * next_transfer - Move to the Next transfer in the current spi message
752  * @pl022: SSP driver private data structure
753  *
754  * This function moves though the linked list of spi transfers in the
755  * current spi message and returns with the state of current spi
756  * message i.e whether its last transfer is done(STATE_DONE) or
757  * Next transfer is ready(STATE_RUNNING)
758  */
759 static void *next_transfer(struct pl022 *pl022)
760 {
761 	struct spi_message *msg = pl022->cur_msg;
762 	struct spi_transfer *trans = pl022->cur_transfer;
763 
764 	/* Move to next transfer */
765 	if (trans->transfer_list.next != &msg->transfers) {
766 		pl022->cur_transfer =
767 		    list_entry(trans->transfer_list.next,
768 			       struct spi_transfer, transfer_list);
769 		return STATE_RUNNING;
770 	}
771 	return STATE_DONE;
772 }
773 
774 /*
775  * This DMA functionality is only compiled in if we have
776  * access to the generic DMA devices/DMA engine.
777  */
778 #ifdef CONFIG_DMA_ENGINE
779 static void unmap_free_dma_scatter(struct pl022 *pl022)
780 {
781 	/* Unmap and free the SG tables */
782 	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
783 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
784 	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
785 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
786 	sg_free_table(&pl022->sgt_rx);
787 	sg_free_table(&pl022->sgt_tx);
788 }
789 
790 static void dma_callback(void *data)
791 {
792 	struct pl022 *pl022 = data;
793 	struct spi_message *msg = pl022->cur_msg;
794 
795 	BUG_ON(!pl022->sgt_rx.sgl);
796 
797 #ifdef VERBOSE_DEBUG
798 	/*
799 	 * Optionally dump out buffers to inspect contents, this is
800 	 * good if you want to convince yourself that the loopback
801 	 * read/write contents are the same, when adopting to a new
802 	 * DMA engine.
803 	 */
804 	{
805 		struct scatterlist *sg;
806 		unsigned int i;
807 
808 		dma_sync_sg_for_cpu(&pl022->adev->dev,
809 				    pl022->sgt_rx.sgl,
810 				    pl022->sgt_rx.nents,
811 				    DMA_FROM_DEVICE);
812 
813 		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
814 			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
815 			print_hex_dump(KERN_ERR, "SPI RX: ",
816 				       DUMP_PREFIX_OFFSET,
817 				       16,
818 				       1,
819 				       sg_virt(sg),
820 				       sg_dma_len(sg),
821 				       1);
822 		}
823 		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
824 			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
825 			print_hex_dump(KERN_ERR, "SPI TX: ",
826 				       DUMP_PREFIX_OFFSET,
827 				       16,
828 				       1,
829 				       sg_virt(sg),
830 				       sg_dma_len(sg),
831 				       1);
832 		}
833 	}
834 #endif
835 
836 	unmap_free_dma_scatter(pl022);
837 
838 	/* Update total bytes transferred */
839 	msg->actual_length += pl022->cur_transfer->len;
840 	if (pl022->cur_transfer->cs_change)
841 		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
842 
843 	/* Move to next transfer */
844 	msg->state = next_transfer(pl022);
845 	tasklet_schedule(&pl022->pump_transfers);
846 }
847 
848 static void setup_dma_scatter(struct pl022 *pl022,
849 			      void *buffer,
850 			      unsigned int length,
851 			      struct sg_table *sgtab)
852 {
853 	struct scatterlist *sg;
854 	int bytesleft = length;
855 	void *bufp = buffer;
856 	int mapbytes;
857 	int i;
858 
859 	if (buffer) {
860 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
861 			/*
862 			 * If there are less bytes left than what fits
863 			 * in the current page (plus page alignment offset)
864 			 * we just feed in this, else we stuff in as much
865 			 * as we can.
866 			 */
867 			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
868 				mapbytes = bytesleft;
869 			else
870 				mapbytes = PAGE_SIZE - offset_in_page(bufp);
871 			sg_set_page(sg, virt_to_page(bufp),
872 				    mapbytes, offset_in_page(bufp));
873 			bufp += mapbytes;
874 			bytesleft -= mapbytes;
875 			dev_dbg(&pl022->adev->dev,
876 				"set RX/TX target page @ %p, %d bytes, %d left\n",
877 				bufp, mapbytes, bytesleft);
878 		}
879 	} else {
880 		/* Map the dummy buffer on every page */
881 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
882 			if (bytesleft < PAGE_SIZE)
883 				mapbytes = bytesleft;
884 			else
885 				mapbytes = PAGE_SIZE;
886 			sg_set_page(sg, virt_to_page(pl022->dummypage),
887 				    mapbytes, 0);
888 			bytesleft -= mapbytes;
889 			dev_dbg(&pl022->adev->dev,
890 				"set RX/TX to dummy page %d bytes, %d left\n",
891 				mapbytes, bytesleft);
892 
893 		}
894 	}
895 	BUG_ON(bytesleft);
896 }
897 
898 /**
899  * configure_dma - configures the channels for the next transfer
900  * @pl022: SSP driver's private data structure
901  */
902 static int configure_dma(struct pl022 *pl022)
903 {
904 	struct dma_slave_config rx_conf = {
905 		.src_addr = SSP_DR(pl022->phybase),
906 		.direction = DMA_DEV_TO_MEM,
907 		.device_fc = false,
908 	};
909 	struct dma_slave_config tx_conf = {
910 		.dst_addr = SSP_DR(pl022->phybase),
911 		.direction = DMA_MEM_TO_DEV,
912 		.device_fc = false,
913 	};
914 	unsigned int pages;
915 	int ret;
916 	int rx_sglen, tx_sglen;
917 	struct dma_chan *rxchan = pl022->dma_rx_channel;
918 	struct dma_chan *txchan = pl022->dma_tx_channel;
919 	struct dma_async_tx_descriptor *rxdesc;
920 	struct dma_async_tx_descriptor *txdesc;
921 
922 	/* Check that the channels are available */
923 	if (!rxchan || !txchan)
924 		return -ENODEV;
925 
926 	/*
927 	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
928 	 * Notice that the DMA engine uses one-to-one mapping. Since we can
929 	 * not trigger on 2 elements this needs explicit mapping rather than
930 	 * calculation.
931 	 */
932 	switch (pl022->rx_lev_trig) {
933 	case SSP_RX_1_OR_MORE_ELEM:
934 		rx_conf.src_maxburst = 1;
935 		break;
936 	case SSP_RX_4_OR_MORE_ELEM:
937 		rx_conf.src_maxburst = 4;
938 		break;
939 	case SSP_RX_8_OR_MORE_ELEM:
940 		rx_conf.src_maxburst = 8;
941 		break;
942 	case SSP_RX_16_OR_MORE_ELEM:
943 		rx_conf.src_maxburst = 16;
944 		break;
945 	case SSP_RX_32_OR_MORE_ELEM:
946 		rx_conf.src_maxburst = 32;
947 		break;
948 	default:
949 		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
950 		break;
951 	}
952 
953 	switch (pl022->tx_lev_trig) {
954 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
955 		tx_conf.dst_maxburst = 1;
956 		break;
957 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
958 		tx_conf.dst_maxburst = 4;
959 		break;
960 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
961 		tx_conf.dst_maxburst = 8;
962 		break;
963 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
964 		tx_conf.dst_maxburst = 16;
965 		break;
966 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
967 		tx_conf.dst_maxburst = 32;
968 		break;
969 	default:
970 		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
971 		break;
972 	}
973 
974 	switch (pl022->read) {
975 	case READING_NULL:
976 		/* Use the same as for writing */
977 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
978 		break;
979 	case READING_U8:
980 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
981 		break;
982 	case READING_U16:
983 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
984 		break;
985 	case READING_U32:
986 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
987 		break;
988 	}
989 
990 	switch (pl022->write) {
991 	case WRITING_NULL:
992 		/* Use the same as for reading */
993 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
994 		break;
995 	case WRITING_U8:
996 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
997 		break;
998 	case WRITING_U16:
999 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1000 		break;
1001 	case WRITING_U32:
1002 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1003 		break;
1004 	}
1005 
1006 	/* SPI pecularity: we need to read and write the same width */
1007 	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1008 		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1009 	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1010 		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1011 	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1012 
1013 	dmaengine_slave_config(rxchan, &rx_conf);
1014 	dmaengine_slave_config(txchan, &tx_conf);
1015 
1016 	/* Create sglists for the transfers */
1017 	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1018 	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1019 
1020 	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1021 	if (ret)
1022 		goto err_alloc_rx_sg;
1023 
1024 	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1025 	if (ret)
1026 		goto err_alloc_tx_sg;
1027 
1028 	/* Fill in the scatterlists for the RX+TX buffers */
1029 	setup_dma_scatter(pl022, pl022->rx,
1030 			  pl022->cur_transfer->len, &pl022->sgt_rx);
1031 	setup_dma_scatter(pl022, pl022->tx,
1032 			  pl022->cur_transfer->len, &pl022->sgt_tx);
1033 
1034 	/* Map DMA buffers */
1035 	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1036 			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1037 	if (!rx_sglen)
1038 		goto err_rx_sgmap;
1039 
1040 	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1041 			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1042 	if (!tx_sglen)
1043 		goto err_tx_sgmap;
1044 
1045 	/* Send both scatterlists */
1046 	rxdesc = dmaengine_prep_slave_sg(rxchan,
1047 				      pl022->sgt_rx.sgl,
1048 				      rx_sglen,
1049 				      DMA_DEV_TO_MEM,
1050 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1051 	if (!rxdesc)
1052 		goto err_rxdesc;
1053 
1054 	txdesc = dmaengine_prep_slave_sg(txchan,
1055 				      pl022->sgt_tx.sgl,
1056 				      tx_sglen,
1057 				      DMA_MEM_TO_DEV,
1058 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1059 	if (!txdesc)
1060 		goto err_txdesc;
1061 
1062 	/* Put the callback on the RX transfer only, that should finish last */
1063 	rxdesc->callback = dma_callback;
1064 	rxdesc->callback_param = pl022;
1065 
1066 	/* Submit and fire RX and TX with TX last so we're ready to read! */
1067 	dmaengine_submit(rxdesc);
1068 	dmaengine_submit(txdesc);
1069 	dma_async_issue_pending(rxchan);
1070 	dma_async_issue_pending(txchan);
1071 	pl022->dma_running = true;
1072 
1073 	return 0;
1074 
1075 err_txdesc:
1076 	dmaengine_terminate_all(txchan);
1077 err_rxdesc:
1078 	dmaengine_terminate_all(rxchan);
1079 	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1080 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1081 err_tx_sgmap:
1082 	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1083 		     pl022->sgt_tx.nents, DMA_FROM_DEVICE);
1084 err_rx_sgmap:
1085 	sg_free_table(&pl022->sgt_tx);
1086 err_alloc_tx_sg:
1087 	sg_free_table(&pl022->sgt_rx);
1088 err_alloc_rx_sg:
1089 	return -ENOMEM;
1090 }
1091 
1092 static int pl022_dma_probe(struct pl022 *pl022)
1093 {
1094 	dma_cap_mask_t mask;
1095 
1096 	/* Try to acquire a generic DMA engine slave channel */
1097 	dma_cap_zero(mask);
1098 	dma_cap_set(DMA_SLAVE, mask);
1099 	/*
1100 	 * We need both RX and TX channels to do DMA, else do none
1101 	 * of them.
1102 	 */
1103 	pl022->dma_rx_channel = dma_request_channel(mask,
1104 					    pl022->master_info->dma_filter,
1105 					    pl022->master_info->dma_rx_param);
1106 	if (!pl022->dma_rx_channel) {
1107 		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1108 		goto err_no_rxchan;
1109 	}
1110 
1111 	pl022->dma_tx_channel = dma_request_channel(mask,
1112 					    pl022->master_info->dma_filter,
1113 					    pl022->master_info->dma_tx_param);
1114 	if (!pl022->dma_tx_channel) {
1115 		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1116 		goto err_no_txchan;
1117 	}
1118 
1119 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1120 	if (!pl022->dummypage) {
1121 		dev_dbg(&pl022->adev->dev, "no DMA dummypage!\n");
1122 		goto err_no_dummypage;
1123 	}
1124 
1125 	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1126 		 dma_chan_name(pl022->dma_rx_channel),
1127 		 dma_chan_name(pl022->dma_tx_channel));
1128 
1129 	return 0;
1130 
1131 err_no_dummypage:
1132 	dma_release_channel(pl022->dma_tx_channel);
1133 err_no_txchan:
1134 	dma_release_channel(pl022->dma_rx_channel);
1135 	pl022->dma_rx_channel = NULL;
1136 err_no_rxchan:
1137 	dev_err(&pl022->adev->dev,
1138 			"Failed to work in dma mode, work without dma!\n");
1139 	return -ENODEV;
1140 }
1141 
1142 static void terminate_dma(struct pl022 *pl022)
1143 {
1144 	struct dma_chan *rxchan = pl022->dma_rx_channel;
1145 	struct dma_chan *txchan = pl022->dma_tx_channel;
1146 
1147 	dmaengine_terminate_all(rxchan);
1148 	dmaengine_terminate_all(txchan);
1149 	unmap_free_dma_scatter(pl022);
1150 	pl022->dma_running = false;
1151 }
1152 
1153 static void pl022_dma_remove(struct pl022 *pl022)
1154 {
1155 	if (pl022->dma_running)
1156 		terminate_dma(pl022);
1157 	if (pl022->dma_tx_channel)
1158 		dma_release_channel(pl022->dma_tx_channel);
1159 	if (pl022->dma_rx_channel)
1160 		dma_release_channel(pl022->dma_rx_channel);
1161 	kfree(pl022->dummypage);
1162 }
1163 
1164 #else
1165 static inline int configure_dma(struct pl022 *pl022)
1166 {
1167 	return -ENODEV;
1168 }
1169 
1170 static inline int pl022_dma_probe(struct pl022 *pl022)
1171 {
1172 	return 0;
1173 }
1174 
1175 static inline void pl022_dma_remove(struct pl022 *pl022)
1176 {
1177 }
1178 #endif
1179 
1180 /**
1181  * pl022_interrupt_handler - Interrupt handler for SSP controller
1182  *
1183  * This function handles interrupts generated for an interrupt based transfer.
1184  * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1185  * current message's state as STATE_ERROR and schedule the tasklet
1186  * pump_transfers which will do the postprocessing of the current message by
1187  * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1188  * more data, and writes data in TX FIFO till it is not full. If we complete
1189  * the transfer we move to the next transfer and schedule the tasklet.
1190  */
1191 static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1192 {
1193 	struct pl022 *pl022 = dev_id;
1194 	struct spi_message *msg = pl022->cur_msg;
1195 	u16 irq_status = 0;
1196 	u16 flag = 0;
1197 
1198 	if (unlikely(!msg)) {
1199 		dev_err(&pl022->adev->dev,
1200 			"bad message state in interrupt handler");
1201 		/* Never fail */
1202 		return IRQ_HANDLED;
1203 	}
1204 
1205 	/* Read the Interrupt Status Register */
1206 	irq_status = readw(SSP_MIS(pl022->virtbase));
1207 
1208 	if (unlikely(!irq_status))
1209 		return IRQ_NONE;
1210 
1211 	/*
1212 	 * This handles the FIFO interrupts, the timeout
1213 	 * interrupts are flatly ignored, they cannot be
1214 	 * trusted.
1215 	 */
1216 	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1217 		/*
1218 		 * Overrun interrupt - bail out since our Data has been
1219 		 * corrupted
1220 		 */
1221 		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1222 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1223 			dev_err(&pl022->adev->dev,
1224 				"RXFIFO is full\n");
1225 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
1226 			dev_err(&pl022->adev->dev,
1227 				"TXFIFO is full\n");
1228 
1229 		/*
1230 		 * Disable and clear interrupts, disable SSP,
1231 		 * mark message with bad status so it can be
1232 		 * retried.
1233 		 */
1234 		writew(DISABLE_ALL_INTERRUPTS,
1235 		       SSP_IMSC(pl022->virtbase));
1236 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1237 		writew((readw(SSP_CR1(pl022->virtbase)) &
1238 			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1239 		msg->state = STATE_ERROR;
1240 
1241 		/* Schedule message queue handler */
1242 		tasklet_schedule(&pl022->pump_transfers);
1243 		return IRQ_HANDLED;
1244 	}
1245 
1246 	readwriter(pl022);
1247 
1248 	if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
1249 		flag = 1;
1250 		/* Disable Transmit interrupt, enable receive interrupt */
1251 		writew((readw(SSP_IMSC(pl022->virtbase)) &
1252 		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1253 		       SSP_IMSC(pl022->virtbase));
1254 	}
1255 
1256 	/*
1257 	 * Since all transactions must write as much as shall be read,
1258 	 * we can conclude the entire transaction once RX is complete.
1259 	 * At this point, all TX will always be finished.
1260 	 */
1261 	if (pl022->rx >= pl022->rx_end) {
1262 		writew(DISABLE_ALL_INTERRUPTS,
1263 		       SSP_IMSC(pl022->virtbase));
1264 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1265 		if (unlikely(pl022->rx > pl022->rx_end)) {
1266 			dev_warn(&pl022->adev->dev, "read %u surplus "
1267 				 "bytes (did you request an odd "
1268 				 "number of bytes on a 16bit bus?)\n",
1269 				 (u32) (pl022->rx - pl022->rx_end));
1270 		}
1271 		/* Update total bytes transferred */
1272 		msg->actual_length += pl022->cur_transfer->len;
1273 		if (pl022->cur_transfer->cs_change)
1274 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1275 		/* Move to next transfer */
1276 		msg->state = next_transfer(pl022);
1277 		tasklet_schedule(&pl022->pump_transfers);
1278 		return IRQ_HANDLED;
1279 	}
1280 
1281 	return IRQ_HANDLED;
1282 }
1283 
1284 /**
1285  * This sets up the pointers to memory for the next message to
1286  * send out on the SPI bus.
1287  */
1288 static int set_up_next_transfer(struct pl022 *pl022,
1289 				struct spi_transfer *transfer)
1290 {
1291 	int residue;
1292 
1293 	/* Sanity check the message for this bus width */
1294 	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1295 	if (unlikely(residue != 0)) {
1296 		dev_err(&pl022->adev->dev,
1297 			"message of %u bytes to transmit but the current "
1298 			"chip bus has a data width of %u bytes!\n",
1299 			pl022->cur_transfer->len,
1300 			pl022->cur_chip->n_bytes);
1301 		dev_err(&pl022->adev->dev, "skipping this message\n");
1302 		return -EIO;
1303 	}
1304 	pl022->tx = (void *)transfer->tx_buf;
1305 	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1306 	pl022->rx = (void *)transfer->rx_buf;
1307 	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1308 	pl022->write =
1309 	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1310 	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1311 	return 0;
1312 }
1313 
1314 /**
1315  * pump_transfers - Tasklet function which schedules next transfer
1316  * when running in interrupt or DMA transfer mode.
1317  * @data: SSP driver private data structure
1318  *
1319  */
1320 static void pump_transfers(unsigned long data)
1321 {
1322 	struct pl022 *pl022 = (struct pl022 *) data;
1323 	struct spi_message *message = NULL;
1324 	struct spi_transfer *transfer = NULL;
1325 	struct spi_transfer *previous = NULL;
1326 
1327 	/* Get current state information */
1328 	message = pl022->cur_msg;
1329 	transfer = pl022->cur_transfer;
1330 
1331 	/* Handle for abort */
1332 	if (message->state == STATE_ERROR) {
1333 		message->status = -EIO;
1334 		giveback(pl022);
1335 		return;
1336 	}
1337 
1338 	/* Handle end of message */
1339 	if (message->state == STATE_DONE) {
1340 		message->status = 0;
1341 		giveback(pl022);
1342 		return;
1343 	}
1344 
1345 	/* Delay if requested at end of transfer before CS change */
1346 	if (message->state == STATE_RUNNING) {
1347 		previous = list_entry(transfer->transfer_list.prev,
1348 					struct spi_transfer,
1349 					transfer_list);
1350 		if (previous->delay_usecs)
1351 			/*
1352 			 * FIXME: This runs in interrupt context.
1353 			 * Is this really smart?
1354 			 */
1355 			udelay(previous->delay_usecs);
1356 
1357 		/* Reselect chip select only if cs_change was requested */
1358 		if (previous->cs_change)
1359 			pl022_cs_control(pl022, SSP_CHIP_SELECT);
1360 	} else {
1361 		/* STATE_START */
1362 		message->state = STATE_RUNNING;
1363 	}
1364 
1365 	if (set_up_next_transfer(pl022, transfer)) {
1366 		message->state = STATE_ERROR;
1367 		message->status = -EIO;
1368 		giveback(pl022);
1369 		return;
1370 	}
1371 	/* Flush the FIFOs and let's go! */
1372 	flush(pl022);
1373 
1374 	if (pl022->cur_chip->enable_dma) {
1375 		if (configure_dma(pl022)) {
1376 			dev_dbg(&pl022->adev->dev,
1377 				"configuration of DMA failed, fall back to interrupt mode\n");
1378 			goto err_config_dma;
1379 		}
1380 		return;
1381 	}
1382 
1383 err_config_dma:
1384 	/* enable all interrupts except RX */
1385 	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1386 }
1387 
1388 static void do_interrupt_dma_transfer(struct pl022 *pl022)
1389 {
1390 	/*
1391 	 * Default is to enable all interrupts except RX -
1392 	 * this will be enabled once TX is complete
1393 	 */
1394 	u32 irqflags = ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM;
1395 
1396 	/* Enable target chip, if not already active */
1397 	if (!pl022->next_msg_cs_active)
1398 		pl022_cs_control(pl022, SSP_CHIP_SELECT);
1399 
1400 	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1401 		/* Error path */
1402 		pl022->cur_msg->state = STATE_ERROR;
1403 		pl022->cur_msg->status = -EIO;
1404 		giveback(pl022);
1405 		return;
1406 	}
1407 	/* If we're using DMA, set up DMA here */
1408 	if (pl022->cur_chip->enable_dma) {
1409 		/* Configure DMA transfer */
1410 		if (configure_dma(pl022)) {
1411 			dev_dbg(&pl022->adev->dev,
1412 				"configuration of DMA failed, fall back to interrupt mode\n");
1413 			goto err_config_dma;
1414 		}
1415 		/* Disable interrupts in DMA mode, IRQ from DMA controller */
1416 		irqflags = DISABLE_ALL_INTERRUPTS;
1417 	}
1418 err_config_dma:
1419 	/* Enable SSP, turn on interrupts */
1420 	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1421 	       SSP_CR1(pl022->virtbase));
1422 	writew(irqflags, SSP_IMSC(pl022->virtbase));
1423 }
1424 
1425 static void do_polling_transfer(struct pl022 *pl022)
1426 {
1427 	struct spi_message *message = NULL;
1428 	struct spi_transfer *transfer = NULL;
1429 	struct spi_transfer *previous = NULL;
1430 	struct chip_data *chip;
1431 	unsigned long time, timeout;
1432 
1433 	chip = pl022->cur_chip;
1434 	message = pl022->cur_msg;
1435 
1436 	while (message->state != STATE_DONE) {
1437 		/* Handle for abort */
1438 		if (message->state == STATE_ERROR)
1439 			break;
1440 		transfer = pl022->cur_transfer;
1441 
1442 		/* Delay if requested at end of transfer */
1443 		if (message->state == STATE_RUNNING) {
1444 			previous =
1445 			    list_entry(transfer->transfer_list.prev,
1446 				       struct spi_transfer, transfer_list);
1447 			if (previous->delay_usecs)
1448 				udelay(previous->delay_usecs);
1449 			if (previous->cs_change)
1450 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1451 		} else {
1452 			/* STATE_START */
1453 			message->state = STATE_RUNNING;
1454 			if (!pl022->next_msg_cs_active)
1455 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1456 		}
1457 
1458 		/* Configuration Changing Per Transfer */
1459 		if (set_up_next_transfer(pl022, transfer)) {
1460 			/* Error path */
1461 			message->state = STATE_ERROR;
1462 			break;
1463 		}
1464 		/* Flush FIFOs and enable SSP */
1465 		flush(pl022);
1466 		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1467 		       SSP_CR1(pl022->virtbase));
1468 
1469 		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1470 
1471 		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1472 		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1473 			time = jiffies;
1474 			readwriter(pl022);
1475 			if (time_after(time, timeout)) {
1476 				dev_warn(&pl022->adev->dev,
1477 				"%s: timeout!\n", __func__);
1478 				message->state = STATE_ERROR;
1479 				goto out;
1480 			}
1481 			cpu_relax();
1482 		}
1483 
1484 		/* Update total byte transferred */
1485 		message->actual_length += pl022->cur_transfer->len;
1486 		if (pl022->cur_transfer->cs_change)
1487 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1488 		/* Move to next transfer */
1489 		message->state = next_transfer(pl022);
1490 	}
1491 out:
1492 	/* Handle end of message */
1493 	if (message->state == STATE_DONE)
1494 		message->status = 0;
1495 	else
1496 		message->status = -EIO;
1497 
1498 	giveback(pl022);
1499 	return;
1500 }
1501 
1502 static int pl022_transfer_one_message(struct spi_master *master,
1503 				      struct spi_message *msg)
1504 {
1505 	struct pl022 *pl022 = spi_master_get_devdata(master);
1506 
1507 	/* Initial message state */
1508 	pl022->cur_msg = msg;
1509 	msg->state = STATE_START;
1510 
1511 	pl022->cur_transfer = list_entry(msg->transfers.next,
1512 					 struct spi_transfer, transfer_list);
1513 
1514 	/* Setup the SPI using the per chip configuration */
1515 	pl022->cur_chip = spi_get_ctldata(msg->spi);
1516 	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1517 
1518 	restore_state(pl022);
1519 	flush(pl022);
1520 
1521 	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1522 		do_polling_transfer(pl022);
1523 	else
1524 		do_interrupt_dma_transfer(pl022);
1525 
1526 	return 0;
1527 }
1528 
1529 static int pl022_prepare_transfer_hardware(struct spi_master *master)
1530 {
1531 	struct pl022 *pl022 = spi_master_get_devdata(master);
1532 
1533 	/*
1534 	 * Just make sure we have all we need to run the transfer by syncing
1535 	 * with the runtime PM framework.
1536 	 */
1537 	pm_runtime_get_sync(&pl022->adev->dev);
1538 	return 0;
1539 }
1540 
1541 static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1542 {
1543 	struct pl022 *pl022 = spi_master_get_devdata(master);
1544 
1545 	/* nothing more to do - disable spi/ssp and power off */
1546 	writew((readw(SSP_CR1(pl022->virtbase)) &
1547 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1548 
1549 	if (pl022->master_info->autosuspend_delay > 0) {
1550 		pm_runtime_mark_last_busy(&pl022->adev->dev);
1551 		pm_runtime_put_autosuspend(&pl022->adev->dev);
1552 	} else {
1553 		pm_runtime_put(&pl022->adev->dev);
1554 	}
1555 
1556 	return 0;
1557 }
1558 
1559 static int verify_controller_parameters(struct pl022 *pl022,
1560 				struct pl022_config_chip const *chip_info)
1561 {
1562 	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1563 	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1564 		dev_err(&pl022->adev->dev,
1565 			"interface is configured incorrectly\n");
1566 		return -EINVAL;
1567 	}
1568 	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1569 	    (!pl022->vendor->unidir)) {
1570 		dev_err(&pl022->adev->dev,
1571 			"unidirectional mode not supported in this "
1572 			"hardware version\n");
1573 		return -EINVAL;
1574 	}
1575 	if ((chip_info->hierarchy != SSP_MASTER)
1576 	    && (chip_info->hierarchy != SSP_SLAVE)) {
1577 		dev_err(&pl022->adev->dev,
1578 			"hierarchy is configured incorrectly\n");
1579 		return -EINVAL;
1580 	}
1581 	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1582 	    && (chip_info->com_mode != DMA_TRANSFER)
1583 	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1584 		dev_err(&pl022->adev->dev,
1585 			"Communication mode is configured incorrectly\n");
1586 		return -EINVAL;
1587 	}
1588 	switch (chip_info->rx_lev_trig) {
1589 	case SSP_RX_1_OR_MORE_ELEM:
1590 	case SSP_RX_4_OR_MORE_ELEM:
1591 	case SSP_RX_8_OR_MORE_ELEM:
1592 		/* These are always OK, all variants can handle this */
1593 		break;
1594 	case SSP_RX_16_OR_MORE_ELEM:
1595 		if (pl022->vendor->fifodepth < 16) {
1596 			dev_err(&pl022->adev->dev,
1597 			"RX FIFO Trigger Level is configured incorrectly\n");
1598 			return -EINVAL;
1599 		}
1600 		break;
1601 	case SSP_RX_32_OR_MORE_ELEM:
1602 		if (pl022->vendor->fifodepth < 32) {
1603 			dev_err(&pl022->adev->dev,
1604 			"RX FIFO Trigger Level is configured incorrectly\n");
1605 			return -EINVAL;
1606 		}
1607 		break;
1608 	default:
1609 		dev_err(&pl022->adev->dev,
1610 			"RX FIFO Trigger Level is configured incorrectly\n");
1611 		return -EINVAL;
1612 		break;
1613 	}
1614 	switch (chip_info->tx_lev_trig) {
1615 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1616 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1617 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1618 		/* These are always OK, all variants can handle this */
1619 		break;
1620 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1621 		if (pl022->vendor->fifodepth < 16) {
1622 			dev_err(&pl022->adev->dev,
1623 			"TX FIFO Trigger Level is configured incorrectly\n");
1624 			return -EINVAL;
1625 		}
1626 		break;
1627 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1628 		if (pl022->vendor->fifodepth < 32) {
1629 			dev_err(&pl022->adev->dev,
1630 			"TX FIFO Trigger Level is configured incorrectly\n");
1631 			return -EINVAL;
1632 		}
1633 		break;
1634 	default:
1635 		dev_err(&pl022->adev->dev,
1636 			"TX FIFO Trigger Level is configured incorrectly\n");
1637 		return -EINVAL;
1638 		break;
1639 	}
1640 	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1641 		if ((chip_info->ctrl_len < SSP_BITS_4)
1642 		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1643 			dev_err(&pl022->adev->dev,
1644 				"CTRL LEN is configured incorrectly\n");
1645 			return -EINVAL;
1646 		}
1647 		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1648 		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1649 			dev_err(&pl022->adev->dev,
1650 				"Wait State is configured incorrectly\n");
1651 			return -EINVAL;
1652 		}
1653 		/* Half duplex is only available in the ST Micro version */
1654 		if (pl022->vendor->extended_cr) {
1655 			if ((chip_info->duplex !=
1656 			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1657 			    && (chip_info->duplex !=
1658 				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1659 				dev_err(&pl022->adev->dev,
1660 					"Microwire duplex mode is configured incorrectly\n");
1661 				return -EINVAL;
1662 			}
1663 		} else {
1664 			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1665 				dev_err(&pl022->adev->dev,
1666 					"Microwire half duplex mode requested,"
1667 					" but this is only available in the"
1668 					" ST version of PL022\n");
1669 			return -EINVAL;
1670 		}
1671 	}
1672 	return 0;
1673 }
1674 
1675 static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1676 {
1677 	return rate / (cpsdvsr * (1 + scr));
1678 }
1679 
1680 static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1681 				    ssp_clock_params * clk_freq)
1682 {
1683 	/* Lets calculate the frequency parameters */
1684 	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1685 	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1686 		best_scr = 0, tmp, found = 0;
1687 
1688 	rate = clk_get_rate(pl022->clk);
1689 	/* cpsdvscr = 2 & scr 0 */
1690 	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1691 	/* cpsdvsr = 254 & scr = 255 */
1692 	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1693 
1694 	if (freq > max_tclk)
1695 		dev_warn(&pl022->adev->dev,
1696 			"Max speed that can be programmed is %d Hz, you requested %d\n",
1697 			max_tclk, freq);
1698 
1699 	if (freq < min_tclk) {
1700 		dev_err(&pl022->adev->dev,
1701 			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1702 			freq, min_tclk);
1703 		return -EINVAL;
1704 	}
1705 
1706 	/*
1707 	 * best_freq will give closest possible available rate (<= requested
1708 	 * freq) for all values of scr & cpsdvsr.
1709 	 */
1710 	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1711 		while (scr <= SCR_MAX) {
1712 			tmp = spi_rate(rate, cpsdvsr, scr);
1713 
1714 			if (tmp > freq) {
1715 				/* we need lower freq */
1716 				scr++;
1717 				continue;
1718 			}
1719 
1720 			/*
1721 			 * If found exact value, mark found and break.
1722 			 * If found more closer value, update and break.
1723 			 */
1724 			if (tmp > best_freq) {
1725 				best_freq = tmp;
1726 				best_cpsdvsr = cpsdvsr;
1727 				best_scr = scr;
1728 
1729 				if (tmp == freq)
1730 					found = 1;
1731 			}
1732 			/*
1733 			 * increased scr will give lower rates, which are not
1734 			 * required
1735 			 */
1736 			break;
1737 		}
1738 		cpsdvsr += 2;
1739 		scr = SCR_MIN;
1740 	}
1741 
1742 	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1743 			freq);
1744 
1745 	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1746 	clk_freq->scr = (u8) (best_scr & 0xFF);
1747 	dev_dbg(&pl022->adev->dev,
1748 		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1749 		freq, best_freq);
1750 	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1751 		clk_freq->cpsdvsr, clk_freq->scr);
1752 
1753 	return 0;
1754 }
1755 
1756 /*
1757  * A piece of default chip info unless the platform
1758  * supplies it.
1759  */
1760 static const struct pl022_config_chip pl022_default_chip_info = {
1761 	.com_mode = POLLING_TRANSFER,
1762 	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1763 	.hierarchy = SSP_SLAVE,
1764 	.slave_tx_disable = DO_NOT_DRIVE_TX,
1765 	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1766 	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1767 	.ctrl_len = SSP_BITS_8,
1768 	.wait_state = SSP_MWIRE_WAIT_ZERO,
1769 	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1770 	.cs_control = null_cs_control,
1771 };
1772 
1773 /**
1774  * pl022_setup - setup function registered to SPI master framework
1775  * @spi: spi device which is requesting setup
1776  *
1777  * This function is registered to the SPI framework for this SPI master
1778  * controller. If it is the first time when setup is called by this device,
1779  * this function will initialize the runtime state for this chip and save
1780  * the same in the device structure. Else it will update the runtime info
1781  * with the updated chip info. Nothing is really being written to the
1782  * controller hardware here, that is not done until the actual transfer
1783  * commence.
1784  */
1785 static int pl022_setup(struct spi_device *spi)
1786 {
1787 	struct pl022_config_chip const *chip_info;
1788 	struct pl022_config_chip chip_info_dt;
1789 	struct chip_data *chip;
1790 	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1791 	int status = 0;
1792 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1793 	unsigned int bits = spi->bits_per_word;
1794 	u32 tmp;
1795 	struct device_node *np = spi->dev.of_node;
1796 
1797 	if (!spi->max_speed_hz)
1798 		return -EINVAL;
1799 
1800 	/* Get controller_state if one is supplied */
1801 	chip = spi_get_ctldata(spi);
1802 
1803 	if (chip == NULL) {
1804 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1805 		if (!chip) {
1806 			dev_err(&spi->dev,
1807 				"cannot allocate controller state\n");
1808 			return -ENOMEM;
1809 		}
1810 		dev_dbg(&spi->dev,
1811 			"allocated memory for controller's runtime state\n");
1812 	}
1813 
1814 	/* Get controller data if one is supplied */
1815 	chip_info = spi->controller_data;
1816 
1817 	if (chip_info == NULL) {
1818 		if (np) {
1819 			chip_info_dt = pl022_default_chip_info;
1820 
1821 			chip_info_dt.hierarchy = SSP_MASTER;
1822 			of_property_read_u32(np, "pl022,interface",
1823 				&chip_info_dt.iface);
1824 			of_property_read_u32(np, "pl022,com-mode",
1825 				&chip_info_dt.com_mode);
1826 			of_property_read_u32(np, "pl022,rx-level-trig",
1827 				&chip_info_dt.rx_lev_trig);
1828 			of_property_read_u32(np, "pl022,tx-level-trig",
1829 				&chip_info_dt.tx_lev_trig);
1830 			of_property_read_u32(np, "pl022,ctrl-len",
1831 				&chip_info_dt.ctrl_len);
1832 			of_property_read_u32(np, "pl022,wait-state",
1833 				&chip_info_dt.wait_state);
1834 			of_property_read_u32(np, "pl022,duplex",
1835 				&chip_info_dt.duplex);
1836 
1837 			chip_info = &chip_info_dt;
1838 		} else {
1839 			chip_info = &pl022_default_chip_info;
1840 			/* spi_board_info.controller_data not is supplied */
1841 			dev_dbg(&spi->dev,
1842 				"using default controller_data settings\n");
1843 		}
1844 	} else
1845 		dev_dbg(&spi->dev,
1846 			"using user supplied controller_data settings\n");
1847 
1848 	/*
1849 	 * We can override with custom divisors, else we use the board
1850 	 * frequency setting
1851 	 */
1852 	if ((0 == chip_info->clk_freq.cpsdvsr)
1853 	    && (0 == chip_info->clk_freq.scr)) {
1854 		status = calculate_effective_freq(pl022,
1855 						  spi->max_speed_hz,
1856 						  &clk_freq);
1857 		if (status < 0)
1858 			goto err_config_params;
1859 	} else {
1860 		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1861 		if ((clk_freq.cpsdvsr % 2) != 0)
1862 			clk_freq.cpsdvsr =
1863 				clk_freq.cpsdvsr - 1;
1864 	}
1865 	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1866 	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1867 		status = -EINVAL;
1868 		dev_err(&spi->dev,
1869 			"cpsdvsr is configured incorrectly\n");
1870 		goto err_config_params;
1871 	}
1872 
1873 	status = verify_controller_parameters(pl022, chip_info);
1874 	if (status) {
1875 		dev_err(&spi->dev, "controller data is incorrect");
1876 		goto err_config_params;
1877 	}
1878 
1879 	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1880 	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1881 
1882 	/* Now set controller state based on controller data */
1883 	chip->xfer_type = chip_info->com_mode;
1884 	if (!chip_info->cs_control) {
1885 		chip->cs_control = null_cs_control;
1886 		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1887 			dev_warn(&spi->dev,
1888 				 "invalid chip select\n");
1889 	} else
1890 		chip->cs_control = chip_info->cs_control;
1891 
1892 	/* Check bits per word with vendor specific range */
1893 	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1894 		status = -ENOTSUPP;
1895 		dev_err(&spi->dev, "illegal data size for this controller!\n");
1896 		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1897 				pl022->vendor->max_bpw);
1898 		goto err_config_params;
1899 	} else if (bits <= 8) {
1900 		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1901 		chip->n_bytes = 1;
1902 		chip->read = READING_U8;
1903 		chip->write = WRITING_U8;
1904 	} else if (bits <= 16) {
1905 		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1906 		chip->n_bytes = 2;
1907 		chip->read = READING_U16;
1908 		chip->write = WRITING_U16;
1909 	} else {
1910 		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1911 		chip->n_bytes = 4;
1912 		chip->read = READING_U32;
1913 		chip->write = WRITING_U32;
1914 	}
1915 
1916 	/* Now Initialize all register settings required for this chip */
1917 	chip->cr0 = 0;
1918 	chip->cr1 = 0;
1919 	chip->dmacr = 0;
1920 	chip->cpsr = 0;
1921 	if ((chip_info->com_mode == DMA_TRANSFER)
1922 	    && ((pl022->master_info)->enable_dma)) {
1923 		chip->enable_dma = true;
1924 		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1925 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1926 			       SSP_DMACR_MASK_RXDMAE, 0);
1927 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1928 			       SSP_DMACR_MASK_TXDMAE, 1);
1929 	} else {
1930 		chip->enable_dma = false;
1931 		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1932 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1933 			       SSP_DMACR_MASK_RXDMAE, 0);
1934 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1935 			       SSP_DMACR_MASK_TXDMAE, 1);
1936 	}
1937 
1938 	chip->cpsr = clk_freq.cpsdvsr;
1939 
1940 	/* Special setup for the ST micro extended control registers */
1941 	if (pl022->vendor->extended_cr) {
1942 		u32 etx;
1943 
1944 		if (pl022->vendor->pl023) {
1945 			/* These bits are only in the PL023 */
1946 			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
1947 				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
1948 		} else {
1949 			/* These bits are in the PL022 but not PL023 */
1950 			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
1951 				       SSP_CR0_MASK_HALFDUP_ST, 5);
1952 			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
1953 				       SSP_CR0_MASK_CSS_ST, 16);
1954 			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1955 				       SSP_CR0_MASK_FRF_ST, 21);
1956 			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
1957 				       SSP_CR1_MASK_MWAIT_ST, 6);
1958 		}
1959 		SSP_WRITE_BITS(chip->cr0, bits - 1,
1960 			       SSP_CR0_MASK_DSS_ST, 0);
1961 
1962 		if (spi->mode & SPI_LSB_FIRST) {
1963 			tmp = SSP_RX_LSB;
1964 			etx = SSP_TX_LSB;
1965 		} else {
1966 			tmp = SSP_RX_MSB;
1967 			etx = SSP_TX_MSB;
1968 		}
1969 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
1970 		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
1971 		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
1972 			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
1973 		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
1974 			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
1975 	} else {
1976 		SSP_WRITE_BITS(chip->cr0, bits - 1,
1977 			       SSP_CR0_MASK_DSS, 0);
1978 		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1979 			       SSP_CR0_MASK_FRF, 4);
1980 	}
1981 
1982 	/* Stuff that is common for all versions */
1983 	if (spi->mode & SPI_CPOL)
1984 		tmp = SSP_CLK_POL_IDLE_HIGH;
1985 	else
1986 		tmp = SSP_CLK_POL_IDLE_LOW;
1987 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
1988 
1989 	if (spi->mode & SPI_CPHA)
1990 		tmp = SSP_CLK_SECOND_EDGE;
1991 	else
1992 		tmp = SSP_CLK_FIRST_EDGE;
1993 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
1994 
1995 	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
1996 	/* Loopback is available on all versions except PL023 */
1997 	if (pl022->vendor->loopback) {
1998 		if (spi->mode & SPI_LOOP)
1999 			tmp = LOOPBACK_ENABLED;
2000 		else
2001 			tmp = LOOPBACK_DISABLED;
2002 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2003 	}
2004 	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2005 	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2006 	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2007 		3);
2008 
2009 	/* Save controller_state */
2010 	spi_set_ctldata(spi, chip);
2011 	return status;
2012  err_config_params:
2013 	spi_set_ctldata(spi, NULL);
2014 	kfree(chip);
2015 	return status;
2016 }
2017 
2018 /**
2019  * pl022_cleanup - cleanup function registered to SPI master framework
2020  * @spi: spi device which is requesting cleanup
2021  *
2022  * This function is registered to the SPI framework for this SPI master
2023  * controller. It will free the runtime state of chip.
2024  */
2025 static void pl022_cleanup(struct spi_device *spi)
2026 {
2027 	struct chip_data *chip = spi_get_ctldata(spi);
2028 
2029 	spi_set_ctldata(spi, NULL);
2030 	kfree(chip);
2031 }
2032 
2033 static struct pl022_ssp_controller *
2034 pl022_platform_data_dt_get(struct device *dev)
2035 {
2036 	struct device_node *np = dev->of_node;
2037 	struct pl022_ssp_controller *pd;
2038 	u32 tmp;
2039 
2040 	if (!np) {
2041 		dev_err(dev, "no dt node defined\n");
2042 		return NULL;
2043 	}
2044 
2045 	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2046 	if (!pd) {
2047 		dev_err(dev, "cannot allocate platform data memory\n");
2048 		return NULL;
2049 	}
2050 
2051 	pd->bus_id = -1;
2052 	of_property_read_u32(np, "num-cs", &tmp);
2053 	pd->num_chipselect = tmp;
2054 	of_property_read_u32(np, "pl022,autosuspend-delay",
2055 			     &pd->autosuspend_delay);
2056 	pd->rt = of_property_read_bool(np, "pl022,rt");
2057 
2058 	return pd;
2059 }
2060 
2061 static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2062 {
2063 	struct device *dev = &adev->dev;
2064 	struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
2065 	struct spi_master *master;
2066 	struct pl022 *pl022 = NULL;	/*Data for this driver */
2067 	struct device_node *np = adev->dev.of_node;
2068 	int status = 0, i, num_cs;
2069 
2070 	dev_info(&adev->dev,
2071 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2072 	if (!platform_info && IS_ENABLED(CONFIG_OF))
2073 		platform_info = pl022_platform_data_dt_get(dev);
2074 
2075 	if (!platform_info) {
2076 		dev_err(dev, "probe: no platform data defined\n");
2077 		return -ENODEV;
2078 	}
2079 
2080 	if (platform_info->num_chipselect) {
2081 		num_cs = platform_info->num_chipselect;
2082 	} else {
2083 		dev_err(dev, "probe: no chip select defined\n");
2084 		return -ENODEV;
2085 	}
2086 
2087 	/* Allocate master with space for data */
2088 	master = spi_alloc_master(dev, sizeof(struct pl022));
2089 	if (master == NULL) {
2090 		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2091 		return -ENOMEM;
2092 	}
2093 
2094 	pl022 = spi_master_get_devdata(master);
2095 	pl022->master = master;
2096 	pl022->master_info = platform_info;
2097 	pl022->adev = adev;
2098 	pl022->vendor = id->data;
2099 	pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
2100 					  GFP_KERNEL);
2101 
2102 	pl022->pinctrl = devm_pinctrl_get(dev);
2103 	if (IS_ERR(pl022->pinctrl)) {
2104 		status = PTR_ERR(pl022->pinctrl);
2105 		goto err_no_pinctrl;
2106 	}
2107 
2108 	pl022->pins_default = pinctrl_lookup_state(pl022->pinctrl,
2109 						 PINCTRL_STATE_DEFAULT);
2110 	/* enable pins to be muxed in and configured */
2111 	if (!IS_ERR(pl022->pins_default)) {
2112 		status = pinctrl_select_state(pl022->pinctrl,
2113 				pl022->pins_default);
2114 		if (status)
2115 			dev_err(dev, "could not set default pins\n");
2116 	} else
2117 		dev_err(dev, "could not get default pinstate\n");
2118 
2119 	pl022->pins_idle = pinctrl_lookup_state(pl022->pinctrl,
2120 					      PINCTRL_STATE_IDLE);
2121 	if (IS_ERR(pl022->pins_idle))
2122 		dev_dbg(dev, "could not get idle pinstate\n");
2123 
2124 	pl022->pins_sleep = pinctrl_lookup_state(pl022->pinctrl,
2125 					       PINCTRL_STATE_SLEEP);
2126 	if (IS_ERR(pl022->pins_sleep))
2127 		dev_dbg(dev, "could not get sleep pinstate\n");
2128 
2129 	/*
2130 	 * Bus Number Which has been Assigned to this SSP controller
2131 	 * on this board
2132 	 */
2133 	master->bus_num = platform_info->bus_id;
2134 	master->num_chipselect = num_cs;
2135 	master->cleanup = pl022_cleanup;
2136 	master->setup = pl022_setup;
2137 	master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
2138 	master->transfer_one_message = pl022_transfer_one_message;
2139 	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2140 	master->rt = platform_info->rt;
2141 	master->dev.of_node = dev->of_node;
2142 
2143 	if (platform_info->num_chipselect && platform_info->chipselects) {
2144 		for (i = 0; i < num_cs; i++)
2145 			pl022->chipselects[i] = platform_info->chipselects[i];
2146 	} else if (IS_ENABLED(CONFIG_OF)) {
2147 		for (i = 0; i < num_cs; i++) {
2148 			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2149 
2150 			if (cs_gpio == -EPROBE_DEFER) {
2151 				status = -EPROBE_DEFER;
2152 				goto err_no_gpio;
2153 			}
2154 
2155 			pl022->chipselects[i] = cs_gpio;
2156 
2157 			if (gpio_is_valid(cs_gpio)) {
2158 				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2159 					dev_err(&adev->dev,
2160 						"could not request %d gpio\n",
2161 						cs_gpio);
2162 				else if (gpio_direction_output(cs_gpio, 1))
2163 					dev_err(&adev->dev,
2164 						"could set gpio %d as output\n",
2165 						cs_gpio);
2166 			}
2167 		}
2168 	}
2169 
2170 	/*
2171 	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2172 	 * always MS bit first on the original pl022.
2173 	 */
2174 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2175 	if (pl022->vendor->extended_cr)
2176 		master->mode_bits |= SPI_LSB_FIRST;
2177 
2178 	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2179 
2180 	status = amba_request_regions(adev, NULL);
2181 	if (status)
2182 		goto err_no_ioregion;
2183 
2184 	pl022->phybase = adev->res.start;
2185 	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2186 				       resource_size(&adev->res));
2187 	if (pl022->virtbase == NULL) {
2188 		status = -ENOMEM;
2189 		goto err_no_ioremap;
2190 	}
2191 	printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n",
2192 	       adev->res.start, pl022->virtbase);
2193 
2194 	pl022->clk = devm_clk_get(&adev->dev, NULL);
2195 	if (IS_ERR(pl022->clk)) {
2196 		status = PTR_ERR(pl022->clk);
2197 		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2198 		goto err_no_clk;
2199 	}
2200 
2201 	status = clk_prepare(pl022->clk);
2202 	if (status) {
2203 		dev_err(&adev->dev, "could not prepare SSP/SPI bus clock\n");
2204 		goto  err_clk_prep;
2205 	}
2206 
2207 	status = clk_enable(pl022->clk);
2208 	if (status) {
2209 		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2210 		goto err_no_clk_en;
2211 	}
2212 
2213 	/* Initialize transfer pump */
2214 	tasklet_init(&pl022->pump_transfers, pump_transfers,
2215 		     (unsigned long)pl022);
2216 
2217 	/* Disable SSP */
2218 	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2219 	       SSP_CR1(pl022->virtbase));
2220 	load_ssp_default_config(pl022);
2221 
2222 	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2223 				  0, "pl022", pl022);
2224 	if (status < 0) {
2225 		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2226 		goto err_no_irq;
2227 	}
2228 
2229 	/* Get DMA channels */
2230 	if (platform_info->enable_dma) {
2231 		status = pl022_dma_probe(pl022);
2232 		if (status != 0)
2233 			platform_info->enable_dma = 0;
2234 	}
2235 
2236 	/* Register with the SPI framework */
2237 	amba_set_drvdata(adev, pl022);
2238 	status = spi_register_master(master);
2239 	if (status != 0) {
2240 		dev_err(&adev->dev,
2241 			"probe - problem registering spi master\n");
2242 		goto err_spi_register;
2243 	}
2244 	dev_dbg(dev, "probe succeeded\n");
2245 
2246 	/* let runtime pm put suspend */
2247 	if (platform_info->autosuspend_delay > 0) {
2248 		dev_info(&adev->dev,
2249 			"will use autosuspend for runtime pm, delay %dms\n",
2250 			platform_info->autosuspend_delay);
2251 		pm_runtime_set_autosuspend_delay(dev,
2252 			platform_info->autosuspend_delay);
2253 		pm_runtime_use_autosuspend(dev);
2254 	}
2255 	pm_runtime_put(dev);
2256 
2257 	return 0;
2258 
2259  err_spi_register:
2260 	if (platform_info->enable_dma)
2261 		pl022_dma_remove(pl022);
2262  err_no_irq:
2263 	clk_disable(pl022->clk);
2264  err_no_clk_en:
2265 	clk_unprepare(pl022->clk);
2266  err_clk_prep:
2267  err_no_clk:
2268  err_no_ioremap:
2269 	amba_release_regions(adev);
2270  err_no_ioregion:
2271  err_no_gpio:
2272  err_no_pinctrl:
2273 	spi_master_put(master);
2274 	return status;
2275 }
2276 
2277 static int
2278 pl022_remove(struct amba_device *adev)
2279 {
2280 	struct pl022 *pl022 = amba_get_drvdata(adev);
2281 
2282 	if (!pl022)
2283 		return 0;
2284 
2285 	/*
2286 	 * undo pm_runtime_put() in probe.  I assume that we're not
2287 	 * accessing the primecell here.
2288 	 */
2289 	pm_runtime_get_noresume(&adev->dev);
2290 
2291 	load_ssp_default_config(pl022);
2292 	if (pl022->master_info->enable_dma)
2293 		pl022_dma_remove(pl022);
2294 
2295 	clk_disable(pl022->clk);
2296 	clk_unprepare(pl022->clk);
2297 	amba_release_regions(adev);
2298 	tasklet_disable(&pl022->pump_transfers);
2299 	spi_unregister_master(pl022->master);
2300 	amba_set_drvdata(adev, NULL);
2301 	return 0;
2302 }
2303 
2304 #if defined(CONFIG_SUSPEND) || defined(CONFIG_PM_RUNTIME)
2305 /*
2306  * These two functions are used from both suspend/resume and
2307  * the runtime counterparts to handle external resources like
2308  * clocks, pins and regulators when going to sleep.
2309  */
2310 static void pl022_suspend_resources(struct pl022 *pl022, bool runtime)
2311 {
2312 	int ret;
2313 	struct pinctrl_state *pins_state;
2314 
2315 	clk_disable(pl022->clk);
2316 
2317 	pins_state = runtime ? pl022->pins_idle : pl022->pins_sleep;
2318 	/* Optionally let pins go into sleep states */
2319 	if (!IS_ERR(pins_state)) {
2320 		ret = pinctrl_select_state(pl022->pinctrl, pins_state);
2321 		if (ret)
2322 			dev_err(&pl022->adev->dev, "could not set %s pins\n",
2323 				runtime ? "idle" : "sleep");
2324 	}
2325 }
2326 
2327 static void pl022_resume_resources(struct pl022 *pl022, bool runtime)
2328 {
2329 	int ret;
2330 
2331 	/* Optionaly enable pins to be muxed in and configured */
2332 	/* First go to the default state */
2333 	if (!IS_ERR(pl022->pins_default)) {
2334 		ret = pinctrl_select_state(pl022->pinctrl, pl022->pins_default);
2335 		if (ret)
2336 			dev_err(&pl022->adev->dev,
2337 				"could not set default pins\n");
2338 	}
2339 
2340 	if (!runtime) {
2341 		/* Then let's idle the pins until the next transfer happens */
2342 		if (!IS_ERR(pl022->pins_idle)) {
2343 			ret = pinctrl_select_state(pl022->pinctrl,
2344 					pl022->pins_idle);
2345 		if (ret)
2346 			dev_err(&pl022->adev->dev,
2347 				"could not set idle pins\n");
2348 		}
2349 	}
2350 
2351 	clk_enable(pl022->clk);
2352 }
2353 #endif
2354 
2355 #ifdef CONFIG_SUSPEND
2356 static int pl022_suspend(struct device *dev)
2357 {
2358 	struct pl022 *pl022 = dev_get_drvdata(dev);
2359 	int ret;
2360 
2361 	ret = spi_master_suspend(pl022->master);
2362 	if (ret) {
2363 		dev_warn(dev, "cannot suspend master\n");
2364 		return ret;
2365 	}
2366 
2367 	pm_runtime_get_sync(dev);
2368 	pl022_suspend_resources(pl022, false);
2369 
2370 	dev_dbg(dev, "suspended\n");
2371 	return 0;
2372 }
2373 
2374 static int pl022_resume(struct device *dev)
2375 {
2376 	struct pl022 *pl022 = dev_get_drvdata(dev);
2377 	int ret;
2378 
2379 	pl022_resume_resources(pl022, false);
2380 	pm_runtime_put(dev);
2381 
2382 	/* Start the queue running */
2383 	ret = spi_master_resume(pl022->master);
2384 	if (ret)
2385 		dev_err(dev, "problem starting queue (%d)\n", ret);
2386 	else
2387 		dev_dbg(dev, "resumed\n");
2388 
2389 	return ret;
2390 }
2391 #endif	/* CONFIG_PM */
2392 
2393 #ifdef CONFIG_PM_RUNTIME
2394 static int pl022_runtime_suspend(struct device *dev)
2395 {
2396 	struct pl022 *pl022 = dev_get_drvdata(dev);
2397 
2398 	pl022_suspend_resources(pl022, true);
2399 	return 0;
2400 }
2401 
2402 static int pl022_runtime_resume(struct device *dev)
2403 {
2404 	struct pl022 *pl022 = dev_get_drvdata(dev);
2405 
2406 	pl022_resume_resources(pl022, true);
2407 	return 0;
2408 }
2409 #endif
2410 
2411 static const struct dev_pm_ops pl022_dev_pm_ops = {
2412 	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2413 	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2414 };
2415 
2416 static struct vendor_data vendor_arm = {
2417 	.fifodepth = 8,
2418 	.max_bpw = 16,
2419 	.unidir = false,
2420 	.extended_cr = false,
2421 	.pl023 = false,
2422 	.loopback = true,
2423 };
2424 
2425 static struct vendor_data vendor_st = {
2426 	.fifodepth = 32,
2427 	.max_bpw = 32,
2428 	.unidir = false,
2429 	.extended_cr = true,
2430 	.pl023 = false,
2431 	.loopback = true,
2432 };
2433 
2434 static struct vendor_data vendor_st_pl023 = {
2435 	.fifodepth = 32,
2436 	.max_bpw = 32,
2437 	.unidir = false,
2438 	.extended_cr = true,
2439 	.pl023 = true,
2440 	.loopback = false,
2441 };
2442 
2443 static struct amba_id pl022_ids[] = {
2444 	{
2445 		/*
2446 		 * ARM PL022 variant, this has a 16bit wide
2447 		 * and 8 locations deep TX/RX FIFO
2448 		 */
2449 		.id	= 0x00041022,
2450 		.mask	= 0x000fffff,
2451 		.data	= &vendor_arm,
2452 	},
2453 	{
2454 		/*
2455 		 * ST Micro derivative, this has 32bit wide
2456 		 * and 32 locations deep TX/RX FIFO
2457 		 */
2458 		.id	= 0x01080022,
2459 		.mask	= 0xffffffff,
2460 		.data	= &vendor_st,
2461 	},
2462 	{
2463 		/*
2464 		 * ST-Ericsson derivative "PL023" (this is not
2465 		 * an official ARM number), this is a PL022 SSP block
2466 		 * stripped to SPI mode only, it has 32bit wide
2467 		 * and 32 locations deep TX/RX FIFO but no extended
2468 		 * CR0/CR1 register
2469 		 */
2470 		.id	= 0x00080023,
2471 		.mask	= 0xffffffff,
2472 		.data	= &vendor_st_pl023,
2473 	},
2474 	{ 0, 0 },
2475 };
2476 
2477 MODULE_DEVICE_TABLE(amba, pl022_ids);
2478 
2479 static struct amba_driver pl022_driver = {
2480 	.drv = {
2481 		.name	= "ssp-pl022",
2482 		.pm	= &pl022_dev_pm_ops,
2483 	},
2484 	.id_table	= pl022_ids,
2485 	.probe		= pl022_probe,
2486 	.remove		= pl022_remove,
2487 };
2488 
2489 static int __init pl022_init(void)
2490 {
2491 	return amba_driver_register(&pl022_driver);
2492 }
2493 subsys_initcall(pl022_init);
2494 
2495 static void __exit pl022_exit(void)
2496 {
2497 	amba_driver_unregister(&pl022_driver);
2498 }
2499 module_exit(pl022_exit);
2500 
2501 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2502 MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2503 MODULE_LICENSE("GPL");
2504