xref: /openbmc/linux/drivers/spi/spi-pl022.c (revision 0bf49ffb)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
4  *
5  * Copyright (C) 2008-2012 ST-Ericsson AB
6  * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
7  *
8  * Author: Linus Walleij <linus.walleij@stericsson.com>
9  *
10  * Initial version inspired by:
11  *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
12  * Initial adoption to PL022 by:
13  *      Sachin Verma <sachin.verma@st.com>
14  */
15 
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include <linux/ioport.h>
20 #include <linux/errno.h>
21 #include <linux/interrupt.h>
22 #include <linux/spi/spi.h>
23 #include <linux/delay.h>
24 #include <linux/clk.h>
25 #include <linux/err.h>
26 #include <linux/amba/bus.h>
27 #include <linux/amba/pl022.h>
28 #include <linux/io.h>
29 #include <linux/slab.h>
30 #include <linux/dmaengine.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/scatterlist.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/gpio.h>
35 #include <linux/of_gpio.h>
36 #include <linux/pinctrl/consumer.h>
37 
38 /*
39  * This macro is used to define some register default values.
40  * reg is masked with mask, the OR:ed with an (again masked)
41  * val shifted sb steps to the left.
42  */
43 #define SSP_WRITE_BITS(reg, val, mask, sb) \
44  ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
45 
46 /*
47  * This macro is also used to define some default values.
48  * It will just shift val by sb steps to the left and mask
49  * the result with mask.
50  */
51 #define GEN_MASK_BITS(val, mask, sb) \
52  (((val)<<(sb)) & (mask))
53 
54 #define DRIVE_TX		0
55 #define DO_NOT_DRIVE_TX		1
56 
57 #define DO_NOT_QUEUE_DMA	0
58 #define QUEUE_DMA		1
59 
60 #define RX_TRANSFER		1
61 #define TX_TRANSFER		2
62 
63 /*
64  * Macros to access SSP Registers with their offsets
65  */
66 #define SSP_CR0(r)	(r + 0x000)
67 #define SSP_CR1(r)	(r + 0x004)
68 #define SSP_DR(r)	(r + 0x008)
69 #define SSP_SR(r)	(r + 0x00C)
70 #define SSP_CPSR(r)	(r + 0x010)
71 #define SSP_IMSC(r)	(r + 0x014)
72 #define SSP_RIS(r)	(r + 0x018)
73 #define SSP_MIS(r)	(r + 0x01C)
74 #define SSP_ICR(r)	(r + 0x020)
75 #define SSP_DMACR(r)	(r + 0x024)
76 #define SSP_CSR(r)	(r + 0x030) /* vendor extension */
77 #define SSP_ITCR(r)	(r + 0x080)
78 #define SSP_ITIP(r)	(r + 0x084)
79 #define SSP_ITOP(r)	(r + 0x088)
80 #define SSP_TDR(r)	(r + 0x08C)
81 
82 #define SSP_PID0(r)	(r + 0xFE0)
83 #define SSP_PID1(r)	(r + 0xFE4)
84 #define SSP_PID2(r)	(r + 0xFE8)
85 #define SSP_PID3(r)	(r + 0xFEC)
86 
87 #define SSP_CID0(r)	(r + 0xFF0)
88 #define SSP_CID1(r)	(r + 0xFF4)
89 #define SSP_CID2(r)	(r + 0xFF8)
90 #define SSP_CID3(r)	(r + 0xFFC)
91 
92 /*
93  * SSP Control Register 0  - SSP_CR0
94  */
95 #define SSP_CR0_MASK_DSS	(0x0FUL << 0)
96 #define SSP_CR0_MASK_FRF	(0x3UL << 4)
97 #define SSP_CR0_MASK_SPO	(0x1UL << 6)
98 #define SSP_CR0_MASK_SPH	(0x1UL << 7)
99 #define SSP_CR0_MASK_SCR	(0xFFUL << 8)
100 
101 /*
102  * The ST version of this block moves som bits
103  * in SSP_CR0 and extends it to 32 bits
104  */
105 #define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
106 #define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
107 #define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
108 #define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
109 
110 /*
111  * SSP Control Register 0  - SSP_CR1
112  */
113 #define SSP_CR1_MASK_LBM	(0x1UL << 0)
114 #define SSP_CR1_MASK_SSE	(0x1UL << 1)
115 #define SSP_CR1_MASK_MS		(0x1UL << 2)
116 #define SSP_CR1_MASK_SOD	(0x1UL << 3)
117 
118 /*
119  * The ST version of this block adds some bits
120  * in SSP_CR1
121  */
122 #define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
123 #define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
124 #define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
125 #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
126 #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
127 /* This one is only in the PL023 variant */
128 #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
129 
130 /*
131  * SSP Status Register - SSP_SR
132  */
133 #define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
134 #define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
135 #define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
136 #define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
137 #define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
138 
139 /*
140  * SSP Clock Prescale Register  - SSP_CPSR
141  */
142 #define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
143 
144 /*
145  * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
146  */
147 #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
148 #define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
149 #define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
150 #define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
151 
152 /*
153  * SSP Raw Interrupt Status Register - SSP_RIS
154  */
155 /* Receive Overrun Raw Interrupt status */
156 #define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
157 /* Receive Timeout Raw Interrupt status */
158 #define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
159 /* Receive FIFO Raw Interrupt status */
160 #define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
161 /* Transmit FIFO Raw Interrupt status */
162 #define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
163 
164 /*
165  * SSP Masked Interrupt Status Register - SSP_MIS
166  */
167 /* Receive Overrun Masked Interrupt status */
168 #define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
169 /* Receive Timeout Masked Interrupt status */
170 #define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
171 /* Receive FIFO Masked Interrupt status */
172 #define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
173 /* Transmit FIFO Masked Interrupt status */
174 #define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
175 
176 /*
177  * SSP Interrupt Clear Register - SSP_ICR
178  */
179 /* Receive Overrun Raw Clear Interrupt bit */
180 #define SSP_ICR_MASK_RORIC		(0x1UL << 0)
181 /* Receive Timeout Clear Interrupt bit */
182 #define SSP_ICR_MASK_RTIC		(0x1UL << 1)
183 
184 /*
185  * SSP DMA Control Register - SSP_DMACR
186  */
187 /* Receive DMA Enable bit */
188 #define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
189 /* Transmit DMA Enable bit */
190 #define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
191 
192 /*
193  * SSP Chip Select Control Register - SSP_CSR
194  * (vendor extension)
195  */
196 #define SSP_CSR_CSVALUE_MASK		(0x1FUL << 0)
197 
198 /*
199  * SSP Integration Test control Register - SSP_ITCR
200  */
201 #define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
202 #define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
203 
204 /*
205  * SSP Integration Test Input Register - SSP_ITIP
206  */
207 #define ITIP_MASK_SSPRXD		 (0x1UL << 0)
208 #define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
209 #define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
210 #define ITIP_MASK_RXDMAC		 (0x1UL << 3)
211 #define ITIP_MASK_TXDMAC		 (0x1UL << 4)
212 #define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
213 
214 /*
215  * SSP Integration Test output Register - SSP_ITOP
216  */
217 #define ITOP_MASK_SSPTXD		 (0x1UL << 0)
218 #define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
219 #define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
220 #define ITOP_MASK_SSPOEn		 (0x1UL << 3)
221 #define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
222 #define ITOP_MASK_RORINTR		 (0x1UL << 5)
223 #define ITOP_MASK_RTINTR		 (0x1UL << 6)
224 #define ITOP_MASK_RXINTR		 (0x1UL << 7)
225 #define ITOP_MASK_TXINTR		 (0x1UL << 8)
226 #define ITOP_MASK_INTR			 (0x1UL << 9)
227 #define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
228 #define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
229 #define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
230 #define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
231 
232 /*
233  * SSP Test Data Register - SSP_TDR
234  */
235 #define TDR_MASK_TESTDATA		(0xFFFFFFFF)
236 
237 /*
238  * Message State
239  * we use the spi_message.state (void *) pointer to
240  * hold a single state value, that's why all this
241  * (void *) casting is done here.
242  */
243 #define STATE_START			((void *) 0)
244 #define STATE_RUNNING			((void *) 1)
245 #define STATE_DONE			((void *) 2)
246 #define STATE_ERROR			((void *) -1)
247 #define STATE_TIMEOUT			((void *) -2)
248 
249 /*
250  * SSP State - Whether Enabled or Disabled
251  */
252 #define SSP_DISABLED			(0)
253 #define SSP_ENABLED			(1)
254 
255 /*
256  * SSP DMA State - Whether DMA Enabled or Disabled
257  */
258 #define SSP_DMA_DISABLED		(0)
259 #define SSP_DMA_ENABLED			(1)
260 
261 /*
262  * SSP Clock Defaults
263  */
264 #define SSP_DEFAULT_CLKRATE 0x2
265 #define SSP_DEFAULT_PRESCALE 0x40
266 
267 /*
268  * SSP Clock Parameter ranges
269  */
270 #define CPSDVR_MIN 0x02
271 #define CPSDVR_MAX 0xFE
272 #define SCR_MIN 0x00
273 #define SCR_MAX 0xFF
274 
275 /*
276  * SSP Interrupt related Macros
277  */
278 #define DEFAULT_SSP_REG_IMSC  0x0UL
279 #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
280 #define ENABLE_ALL_INTERRUPTS ( \
281 	SSP_IMSC_MASK_RORIM | \
282 	SSP_IMSC_MASK_RTIM | \
283 	SSP_IMSC_MASK_RXIM | \
284 	SSP_IMSC_MASK_TXIM \
285 )
286 
287 #define CLEAR_ALL_INTERRUPTS  0x3
288 
289 #define SPI_POLLING_TIMEOUT 1000
290 
291 /*
292  * The type of reading going on on this chip
293  */
294 enum ssp_reading {
295 	READING_NULL,
296 	READING_U8,
297 	READING_U16,
298 	READING_U32
299 };
300 
301 /*
302  * The type of writing going on on this chip
303  */
304 enum ssp_writing {
305 	WRITING_NULL,
306 	WRITING_U8,
307 	WRITING_U16,
308 	WRITING_U32
309 };
310 
311 /**
312  * struct vendor_data - vendor-specific config parameters
313  * for PL022 derivates
314  * @fifodepth: depth of FIFOs (both)
315  * @max_bpw: maximum number of bits per word
316  * @unidir: supports unidirection transfers
317  * @extended_cr: 32 bit wide control register 0 with extra
318  * features and extra features in CR1 as found in the ST variants
319  * @pl023: supports a subset of the ST extensions called "PL023"
320  * @loopback: supports loopback mode
321  * @internal_cs_ctrl: supports chip select control register
322  */
323 struct vendor_data {
324 	int fifodepth;
325 	int max_bpw;
326 	bool unidir;
327 	bool extended_cr;
328 	bool pl023;
329 	bool loopback;
330 	bool internal_cs_ctrl;
331 };
332 
333 /**
334  * struct pl022 - This is the private SSP driver data structure
335  * @adev: AMBA device model hookup
336  * @vendor: vendor data for the IP block
337  * @phybase: the physical memory where the SSP device resides
338  * @virtbase: the virtual memory where the SSP is mapped
339  * @clk: outgoing clock "SPICLK" for the SPI bus
340  * @master: SPI framework hookup
341  * @master_info: controller-specific data from machine setup
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  * @rx_lev_trig: receive FIFO watermark level which triggers IRQ
358  * @tx_lev_trig: transmit FIFO watermark level which triggers IRQ
359  * @dma_rx_channel: optional channel for RX DMA
360  * @dma_tx_channel: optional channel for TX DMA
361  * @sgt_rx: scattertable for the RX transfer
362  * @sgt_tx: scattertable for the TX transfer
363  * @dummypage: a dummy page used for driving data on the bus with DMA
364  * @dma_running: indicates whether DMA is in operation
365  * @cur_cs: current chip select (gpio)
366  * @chipselects: list of chipselects (gpios)
367  */
368 struct pl022 {
369 	struct amba_device		*adev;
370 	struct vendor_data		*vendor;
371 	resource_size_t			phybase;
372 	void __iomem			*virtbase;
373 	struct clk			*clk;
374 	struct spi_master		*master;
375 	struct pl022_ssp_controller	*master_info;
376 	/* Message per-transfer pump */
377 	struct tasklet_struct		pump_transfers;
378 	struct spi_message		*cur_msg;
379 	struct spi_transfer		*cur_transfer;
380 	struct chip_data		*cur_chip;
381 	bool				next_msg_cs_active;
382 	void				*tx;
383 	void				*tx_end;
384 	void				*rx;
385 	void				*rx_end;
386 	enum ssp_reading		read;
387 	enum ssp_writing		write;
388 	u32				exp_fifo_level;
389 	enum ssp_rx_level_trig		rx_lev_trig;
390 	enum ssp_tx_level_trig		tx_lev_trig;
391 	/* DMA settings */
392 #ifdef CONFIG_DMA_ENGINE
393 	struct dma_chan			*dma_rx_channel;
394 	struct dma_chan			*dma_tx_channel;
395 	struct sg_table			sgt_rx;
396 	struct sg_table			sgt_tx;
397 	char				*dummypage;
398 	bool				dma_running;
399 #endif
400 	int cur_cs;
401 	int *chipselects;
402 };
403 
404 /**
405  * struct chip_data - To maintain runtime state of SSP for each client chip
406  * @cr0: Value of control register CR0 of SSP - on later ST variants this
407  *       register is 32 bits wide rather than just 16
408  * @cr1: Value of control register CR1 of SSP
409  * @dmacr: Value of DMA control Register of SSP
410  * @cpsr: Value of Clock prescale register
411  * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
412  * @enable_dma: Whether to enable DMA or not
413  * @read: function ptr to be used to read when doing xfer for this chip
414  * @write: function ptr to be used to write when doing xfer for this chip
415  * @cs_control: chip select callback provided by chip
416  * @xfer_type: polling/interrupt/DMA
417  *
418  * Runtime state of the SSP controller, maintained per chip,
419  * This would be set according to the current message that would be served
420  */
421 struct chip_data {
422 	u32 cr0;
423 	u16 cr1;
424 	u16 dmacr;
425 	u16 cpsr;
426 	u8 n_bytes;
427 	bool enable_dma;
428 	enum ssp_reading read;
429 	enum ssp_writing write;
430 	void (*cs_control) (u32 command);
431 	int xfer_type;
432 };
433 
434 /**
435  * null_cs_control - Dummy chip select function
436  * @command: select/delect the chip
437  *
438  * If no chip select function is provided by client this is used as dummy
439  * chip select
440  */
441 static void null_cs_control(u32 command)
442 {
443 	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
444 }
445 
446 /**
447  * internal_cs_control - Control chip select signals via SSP_CSR.
448  * @pl022: SSP driver private data structure
449  * @command: select/delect the chip
450  *
451  * Used on controller with internal chip select control via SSP_CSR register
452  * (vendor extension). Each of the 5 LSB in the register controls one chip
453  * select signal.
454  */
455 static void internal_cs_control(struct pl022 *pl022, u32 command)
456 {
457 	u32 tmp;
458 
459 	tmp = readw(SSP_CSR(pl022->virtbase));
460 	if (command == SSP_CHIP_SELECT)
461 		tmp &= ~BIT(pl022->cur_cs);
462 	else
463 		tmp |= BIT(pl022->cur_cs);
464 	writew(tmp, SSP_CSR(pl022->virtbase));
465 }
466 
467 static void pl022_cs_control(struct pl022 *pl022, u32 command)
468 {
469 	if (pl022->vendor->internal_cs_ctrl)
470 		internal_cs_control(pl022, command);
471 	else if (gpio_is_valid(pl022->cur_cs))
472 		gpio_set_value(pl022->cur_cs, command);
473 	else
474 		pl022->cur_chip->cs_control(command);
475 }
476 
477 /**
478  * giveback - current spi_message is over, schedule next message and call
479  * callback of this message. Assumes that caller already
480  * set message->status; dma and pio irqs are blocked
481  * @pl022: SSP driver private data structure
482  */
483 static void giveback(struct pl022 *pl022)
484 {
485 	struct spi_transfer *last_transfer;
486 	pl022->next_msg_cs_active = false;
487 
488 	last_transfer = list_last_entry(&pl022->cur_msg->transfers,
489 					struct spi_transfer, transfer_list);
490 
491 	/* Delay if requested before any change in chip select */
492 	/*
493 	 * FIXME: This runs in interrupt context.
494 	 * Is this really smart?
495 	 */
496 	spi_transfer_delay_exec(last_transfer);
497 
498 	if (!last_transfer->cs_change) {
499 		struct spi_message *next_msg;
500 
501 		/*
502 		 * cs_change was not set. We can keep the chip select
503 		 * enabled if there is message in the queue and it is
504 		 * for the same spi device.
505 		 *
506 		 * We cannot postpone this until pump_messages, because
507 		 * after calling msg->complete (below) the driver that
508 		 * sent the current message could be unloaded, which
509 		 * could invalidate the cs_control() callback...
510 		 */
511 		/* get a pointer to the next message, if any */
512 		next_msg = spi_get_next_queued_message(pl022->master);
513 
514 		/*
515 		 * see if the next and current messages point
516 		 * to the same spi device.
517 		 */
518 		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
519 			next_msg = NULL;
520 		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
521 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
522 		else
523 			pl022->next_msg_cs_active = true;
524 
525 	}
526 
527 	pl022->cur_msg = NULL;
528 	pl022->cur_transfer = NULL;
529 	pl022->cur_chip = NULL;
530 
531 	/* disable the SPI/SSP operation */
532 	writew((readw(SSP_CR1(pl022->virtbase)) &
533 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
534 
535 	spi_finalize_current_message(pl022->master);
536 }
537 
538 /**
539  * flush - flush the FIFO to reach a clean state
540  * @pl022: SSP driver private data structure
541  */
542 static int flush(struct pl022 *pl022)
543 {
544 	unsigned long limit = loops_per_jiffy << 1;
545 
546 	dev_dbg(&pl022->adev->dev, "flush\n");
547 	do {
548 		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
549 			readw(SSP_DR(pl022->virtbase));
550 	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
551 
552 	pl022->exp_fifo_level = 0;
553 
554 	return limit;
555 }
556 
557 /**
558  * restore_state - Load configuration of current chip
559  * @pl022: SSP driver private data structure
560  */
561 static void restore_state(struct pl022 *pl022)
562 {
563 	struct chip_data *chip = pl022->cur_chip;
564 
565 	if (pl022->vendor->extended_cr)
566 		writel(chip->cr0, SSP_CR0(pl022->virtbase));
567 	else
568 		writew(chip->cr0, SSP_CR0(pl022->virtbase));
569 	writew(chip->cr1, SSP_CR1(pl022->virtbase));
570 	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
571 	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
572 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
573 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
574 }
575 
576 /*
577  * Default SSP Register Values
578  */
579 #define DEFAULT_SSP_REG_CR0 ( \
580 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
581 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
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 /* ST versions have slightly different bit layout */
588 #define DEFAULT_SSP_REG_CR0_ST ( \
589 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
590 	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
591 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
592 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
593 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
594 	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
595 	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
596 )
597 
598 /* The PL023 version is slightly different again */
599 #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
600 	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
601 	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
602 	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
603 	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
604 )
605 
606 #define DEFAULT_SSP_REG_CR1 ( \
607 	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
608 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
609 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
610 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
611 )
612 
613 /* ST versions extend this register to use all 16 bits */
614 #define DEFAULT_SSP_REG_CR1_ST ( \
615 	DEFAULT_SSP_REG_CR1 | \
616 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
617 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
618 	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
619 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
620 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
621 )
622 
623 /*
624  * The PL023 variant has further differences: no loopback mode, no microwire
625  * support, and a new clock feedback delay setting.
626  */
627 #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
628 	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
629 	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
630 	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
631 	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
632 	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
633 	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
634 	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
635 	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
636 )
637 
638 #define DEFAULT_SSP_REG_CPSR ( \
639 	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
640 )
641 
642 #define DEFAULT_SSP_REG_DMACR (\
643 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
644 	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
645 )
646 
647 /**
648  * load_ssp_default_config - Load default configuration for SSP
649  * @pl022: SSP driver private data structure
650  */
651 static void load_ssp_default_config(struct pl022 *pl022)
652 {
653 	if (pl022->vendor->pl023) {
654 		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
655 		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
656 	} else if (pl022->vendor->extended_cr) {
657 		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
658 		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
659 	} else {
660 		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
661 		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
662 	}
663 	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
664 	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
665 	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
666 	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
667 }
668 
669 /*
670  * This will write to TX and read from RX according to the parameters
671  * set in pl022.
672  */
673 static void readwriter(struct pl022 *pl022)
674 {
675 
676 	/*
677 	 * The FIFO depth is different between primecell variants.
678 	 * I believe filling in too much in the FIFO might cause
679 	 * errons in 8bit wide transfers on ARM variants (just 8 words
680 	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
681 	 *
682 	 * To prevent this issue, the TX FIFO is only filled to the
683 	 * unused RX FIFO fill length, regardless of what the TX
684 	 * FIFO status flag indicates.
685 	 */
686 	dev_dbg(&pl022->adev->dev,
687 		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
688 		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
689 
690 	/* Read as much as you can */
691 	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
692 	       && (pl022->rx < pl022->rx_end)) {
693 		switch (pl022->read) {
694 		case READING_NULL:
695 			readw(SSP_DR(pl022->virtbase));
696 			break;
697 		case READING_U8:
698 			*(u8 *) (pl022->rx) =
699 				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
700 			break;
701 		case READING_U16:
702 			*(u16 *) (pl022->rx) =
703 				(u16) readw(SSP_DR(pl022->virtbase));
704 			break;
705 		case READING_U32:
706 			*(u32 *) (pl022->rx) =
707 				readl(SSP_DR(pl022->virtbase));
708 			break;
709 		}
710 		pl022->rx += (pl022->cur_chip->n_bytes);
711 		pl022->exp_fifo_level--;
712 	}
713 	/*
714 	 * Write as much as possible up to the RX FIFO size
715 	 */
716 	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
717 	       && (pl022->tx < pl022->tx_end)) {
718 		switch (pl022->write) {
719 		case WRITING_NULL:
720 			writew(0x0, SSP_DR(pl022->virtbase));
721 			break;
722 		case WRITING_U8:
723 			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
724 			break;
725 		case WRITING_U16:
726 			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
727 			break;
728 		case WRITING_U32:
729 			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
730 			break;
731 		}
732 		pl022->tx += (pl022->cur_chip->n_bytes);
733 		pl022->exp_fifo_level++;
734 		/*
735 		 * This inner reader takes care of things appearing in the RX
736 		 * FIFO as we're transmitting. This will happen a lot since the
737 		 * clock starts running when you put things into the TX FIFO,
738 		 * and then things are continuously clocked into the RX FIFO.
739 		 */
740 		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
741 		       && (pl022->rx < pl022->rx_end)) {
742 			switch (pl022->read) {
743 			case READING_NULL:
744 				readw(SSP_DR(pl022->virtbase));
745 				break;
746 			case READING_U8:
747 				*(u8 *) (pl022->rx) =
748 					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
749 				break;
750 			case READING_U16:
751 				*(u16 *) (pl022->rx) =
752 					(u16) readw(SSP_DR(pl022->virtbase));
753 				break;
754 			case READING_U32:
755 				*(u32 *) (pl022->rx) =
756 					readl(SSP_DR(pl022->virtbase));
757 				break;
758 			}
759 			pl022->rx += (pl022->cur_chip->n_bytes);
760 			pl022->exp_fifo_level--;
761 		}
762 	}
763 	/*
764 	 * When we exit here the TX FIFO should be full and the RX FIFO
765 	 * should be empty
766 	 */
767 }
768 
769 /**
770  * next_transfer - Move to the Next transfer in the current spi message
771  * @pl022: SSP driver private data structure
772  *
773  * This function moves though the linked list of spi transfers in the
774  * current spi message and returns with the state of current spi
775  * message i.e whether its last transfer is done(STATE_DONE) or
776  * Next transfer is ready(STATE_RUNNING)
777  */
778 static void *next_transfer(struct pl022 *pl022)
779 {
780 	struct spi_message *msg = pl022->cur_msg;
781 	struct spi_transfer *trans = pl022->cur_transfer;
782 
783 	/* Move to next transfer */
784 	if (trans->transfer_list.next != &msg->transfers) {
785 		pl022->cur_transfer =
786 		    list_entry(trans->transfer_list.next,
787 			       struct spi_transfer, transfer_list);
788 		return STATE_RUNNING;
789 	}
790 	return STATE_DONE;
791 }
792 
793 /*
794  * This DMA functionality is only compiled in if we have
795  * access to the generic DMA devices/DMA engine.
796  */
797 #ifdef CONFIG_DMA_ENGINE
798 static void unmap_free_dma_scatter(struct pl022 *pl022)
799 {
800 	/* Unmap and free the SG tables */
801 	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
802 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
803 	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
804 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
805 	sg_free_table(&pl022->sgt_rx);
806 	sg_free_table(&pl022->sgt_tx);
807 }
808 
809 static void dma_callback(void *data)
810 {
811 	struct pl022 *pl022 = data;
812 	struct spi_message *msg = pl022->cur_msg;
813 
814 	BUG_ON(!pl022->sgt_rx.sgl);
815 
816 #ifdef VERBOSE_DEBUG
817 	/*
818 	 * Optionally dump out buffers to inspect contents, this is
819 	 * good if you want to convince yourself that the loopback
820 	 * read/write contents are the same, when adopting to a new
821 	 * DMA engine.
822 	 */
823 	{
824 		struct scatterlist *sg;
825 		unsigned int i;
826 
827 		dma_sync_sg_for_cpu(&pl022->adev->dev,
828 				    pl022->sgt_rx.sgl,
829 				    pl022->sgt_rx.nents,
830 				    DMA_FROM_DEVICE);
831 
832 		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
833 			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
834 			print_hex_dump(KERN_ERR, "SPI RX: ",
835 				       DUMP_PREFIX_OFFSET,
836 				       16,
837 				       1,
838 				       sg_virt(sg),
839 				       sg_dma_len(sg),
840 				       1);
841 		}
842 		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
843 			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
844 			print_hex_dump(KERN_ERR, "SPI TX: ",
845 				       DUMP_PREFIX_OFFSET,
846 				       16,
847 				       1,
848 				       sg_virt(sg),
849 				       sg_dma_len(sg),
850 				       1);
851 		}
852 	}
853 #endif
854 
855 	unmap_free_dma_scatter(pl022);
856 
857 	/* Update total bytes transferred */
858 	msg->actual_length += pl022->cur_transfer->len;
859 	/* Move to next transfer */
860 	msg->state = next_transfer(pl022);
861 	if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
862 		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
863 	tasklet_schedule(&pl022->pump_transfers);
864 }
865 
866 static void setup_dma_scatter(struct pl022 *pl022,
867 			      void *buffer,
868 			      unsigned int length,
869 			      struct sg_table *sgtab)
870 {
871 	struct scatterlist *sg;
872 	int bytesleft = length;
873 	void *bufp = buffer;
874 	int mapbytes;
875 	int i;
876 
877 	if (buffer) {
878 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
879 			/*
880 			 * If there are less bytes left than what fits
881 			 * in the current page (plus page alignment offset)
882 			 * we just feed in this, else we stuff in as much
883 			 * as we can.
884 			 */
885 			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
886 				mapbytes = bytesleft;
887 			else
888 				mapbytes = PAGE_SIZE - offset_in_page(bufp);
889 			sg_set_page(sg, virt_to_page(bufp),
890 				    mapbytes, offset_in_page(bufp));
891 			bufp += mapbytes;
892 			bytesleft -= mapbytes;
893 			dev_dbg(&pl022->adev->dev,
894 				"set RX/TX target page @ %p, %d bytes, %d left\n",
895 				bufp, mapbytes, bytesleft);
896 		}
897 	} else {
898 		/* Map the dummy buffer on every page */
899 		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
900 			if (bytesleft < PAGE_SIZE)
901 				mapbytes = bytesleft;
902 			else
903 				mapbytes = PAGE_SIZE;
904 			sg_set_page(sg, virt_to_page(pl022->dummypage),
905 				    mapbytes, 0);
906 			bytesleft -= mapbytes;
907 			dev_dbg(&pl022->adev->dev,
908 				"set RX/TX to dummy page %d bytes, %d left\n",
909 				mapbytes, bytesleft);
910 
911 		}
912 	}
913 	BUG_ON(bytesleft);
914 }
915 
916 /**
917  * configure_dma - configures the channels for the next transfer
918  * @pl022: SSP driver's private data structure
919  */
920 static int configure_dma(struct pl022 *pl022)
921 {
922 	struct dma_slave_config rx_conf = {
923 		.src_addr = SSP_DR(pl022->phybase),
924 		.direction = DMA_DEV_TO_MEM,
925 		.device_fc = false,
926 	};
927 	struct dma_slave_config tx_conf = {
928 		.dst_addr = SSP_DR(pl022->phybase),
929 		.direction = DMA_MEM_TO_DEV,
930 		.device_fc = false,
931 	};
932 	unsigned int pages;
933 	int ret;
934 	int rx_sglen, tx_sglen;
935 	struct dma_chan *rxchan = pl022->dma_rx_channel;
936 	struct dma_chan *txchan = pl022->dma_tx_channel;
937 	struct dma_async_tx_descriptor *rxdesc;
938 	struct dma_async_tx_descriptor *txdesc;
939 
940 	/* Check that the channels are available */
941 	if (!rxchan || !txchan)
942 		return -ENODEV;
943 
944 	/*
945 	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
946 	 * Notice that the DMA engine uses one-to-one mapping. Since we can
947 	 * not trigger on 2 elements this needs explicit mapping rather than
948 	 * calculation.
949 	 */
950 	switch (pl022->rx_lev_trig) {
951 	case SSP_RX_1_OR_MORE_ELEM:
952 		rx_conf.src_maxburst = 1;
953 		break;
954 	case SSP_RX_4_OR_MORE_ELEM:
955 		rx_conf.src_maxburst = 4;
956 		break;
957 	case SSP_RX_8_OR_MORE_ELEM:
958 		rx_conf.src_maxburst = 8;
959 		break;
960 	case SSP_RX_16_OR_MORE_ELEM:
961 		rx_conf.src_maxburst = 16;
962 		break;
963 	case SSP_RX_32_OR_MORE_ELEM:
964 		rx_conf.src_maxburst = 32;
965 		break;
966 	default:
967 		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
968 		break;
969 	}
970 
971 	switch (pl022->tx_lev_trig) {
972 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
973 		tx_conf.dst_maxburst = 1;
974 		break;
975 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
976 		tx_conf.dst_maxburst = 4;
977 		break;
978 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
979 		tx_conf.dst_maxburst = 8;
980 		break;
981 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
982 		tx_conf.dst_maxburst = 16;
983 		break;
984 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
985 		tx_conf.dst_maxburst = 32;
986 		break;
987 	default:
988 		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
989 		break;
990 	}
991 
992 	switch (pl022->read) {
993 	case READING_NULL:
994 		/* Use the same as for writing */
995 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
996 		break;
997 	case READING_U8:
998 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
999 		break;
1000 	case READING_U16:
1001 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1002 		break;
1003 	case READING_U32:
1004 		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1005 		break;
1006 	}
1007 
1008 	switch (pl022->write) {
1009 	case WRITING_NULL:
1010 		/* Use the same as for reading */
1011 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1012 		break;
1013 	case WRITING_U8:
1014 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1015 		break;
1016 	case WRITING_U16:
1017 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1018 		break;
1019 	case WRITING_U32:
1020 		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1021 		break;
1022 	}
1023 
1024 	/* SPI pecularity: we need to read and write the same width */
1025 	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1026 		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1027 	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1028 		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1029 	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1030 
1031 	dmaengine_slave_config(rxchan, &rx_conf);
1032 	dmaengine_slave_config(txchan, &tx_conf);
1033 
1034 	/* Create sglists for the transfers */
1035 	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1036 	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1037 
1038 	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1039 	if (ret)
1040 		goto err_alloc_rx_sg;
1041 
1042 	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1043 	if (ret)
1044 		goto err_alloc_tx_sg;
1045 
1046 	/* Fill in the scatterlists for the RX+TX buffers */
1047 	setup_dma_scatter(pl022, pl022->rx,
1048 			  pl022->cur_transfer->len, &pl022->sgt_rx);
1049 	setup_dma_scatter(pl022, pl022->tx,
1050 			  pl022->cur_transfer->len, &pl022->sgt_tx);
1051 
1052 	/* Map DMA buffers */
1053 	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1054 			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1055 	if (!rx_sglen)
1056 		goto err_rx_sgmap;
1057 
1058 	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1059 			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1060 	if (!tx_sglen)
1061 		goto err_tx_sgmap;
1062 
1063 	/* Send both scatterlists */
1064 	rxdesc = dmaengine_prep_slave_sg(rxchan,
1065 				      pl022->sgt_rx.sgl,
1066 				      rx_sglen,
1067 				      DMA_DEV_TO_MEM,
1068 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1069 	if (!rxdesc)
1070 		goto err_rxdesc;
1071 
1072 	txdesc = dmaengine_prep_slave_sg(txchan,
1073 				      pl022->sgt_tx.sgl,
1074 				      tx_sglen,
1075 				      DMA_MEM_TO_DEV,
1076 				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1077 	if (!txdesc)
1078 		goto err_txdesc;
1079 
1080 	/* Put the callback on the RX transfer only, that should finish last */
1081 	rxdesc->callback = dma_callback;
1082 	rxdesc->callback_param = pl022;
1083 
1084 	/* Submit and fire RX and TX with TX last so we're ready to read! */
1085 	dmaengine_submit(rxdesc);
1086 	dmaengine_submit(txdesc);
1087 	dma_async_issue_pending(rxchan);
1088 	dma_async_issue_pending(txchan);
1089 	pl022->dma_running = true;
1090 
1091 	return 0;
1092 
1093 err_txdesc:
1094 	dmaengine_terminate_all(txchan);
1095 err_rxdesc:
1096 	dmaengine_terminate_all(rxchan);
1097 	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1098 		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1099 err_tx_sgmap:
1100 	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1101 		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1102 err_rx_sgmap:
1103 	sg_free_table(&pl022->sgt_tx);
1104 err_alloc_tx_sg:
1105 	sg_free_table(&pl022->sgt_rx);
1106 err_alloc_rx_sg:
1107 	return -ENOMEM;
1108 }
1109 
1110 static int pl022_dma_probe(struct pl022 *pl022)
1111 {
1112 	dma_cap_mask_t mask;
1113 
1114 	/* Try to acquire a generic DMA engine slave channel */
1115 	dma_cap_zero(mask);
1116 	dma_cap_set(DMA_SLAVE, mask);
1117 	/*
1118 	 * We need both RX and TX channels to do DMA, else do none
1119 	 * of them.
1120 	 */
1121 	pl022->dma_rx_channel = dma_request_channel(mask,
1122 					    pl022->master_info->dma_filter,
1123 					    pl022->master_info->dma_rx_param);
1124 	if (!pl022->dma_rx_channel) {
1125 		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1126 		goto err_no_rxchan;
1127 	}
1128 
1129 	pl022->dma_tx_channel = dma_request_channel(mask,
1130 					    pl022->master_info->dma_filter,
1131 					    pl022->master_info->dma_tx_param);
1132 	if (!pl022->dma_tx_channel) {
1133 		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1134 		goto err_no_txchan;
1135 	}
1136 
1137 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1138 	if (!pl022->dummypage)
1139 		goto err_no_dummypage;
1140 
1141 	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1142 		 dma_chan_name(pl022->dma_rx_channel),
1143 		 dma_chan_name(pl022->dma_tx_channel));
1144 
1145 	return 0;
1146 
1147 err_no_dummypage:
1148 	dma_release_channel(pl022->dma_tx_channel);
1149 err_no_txchan:
1150 	dma_release_channel(pl022->dma_rx_channel);
1151 	pl022->dma_rx_channel = NULL;
1152 err_no_rxchan:
1153 	dev_err(&pl022->adev->dev,
1154 			"Failed to work in dma mode, work without dma!\n");
1155 	return -ENODEV;
1156 }
1157 
1158 static int pl022_dma_autoprobe(struct pl022 *pl022)
1159 {
1160 	struct device *dev = &pl022->adev->dev;
1161 	struct dma_chan *chan;
1162 	int err;
1163 
1164 	/* automatically configure DMA channels from platform, normally using DT */
1165 	chan = dma_request_chan(dev, "rx");
1166 	if (IS_ERR(chan)) {
1167 		err = PTR_ERR(chan);
1168 		goto err_no_rxchan;
1169 	}
1170 
1171 	pl022->dma_rx_channel = chan;
1172 
1173 	chan = dma_request_chan(dev, "tx");
1174 	if (IS_ERR(chan)) {
1175 		err = PTR_ERR(chan);
1176 		goto err_no_txchan;
1177 	}
1178 
1179 	pl022->dma_tx_channel = chan;
1180 
1181 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1182 	if (!pl022->dummypage) {
1183 		err = -ENOMEM;
1184 		goto err_no_dummypage;
1185 	}
1186 
1187 	return 0;
1188 
1189 err_no_dummypage:
1190 	dma_release_channel(pl022->dma_tx_channel);
1191 	pl022->dma_tx_channel = NULL;
1192 err_no_txchan:
1193 	dma_release_channel(pl022->dma_rx_channel);
1194 	pl022->dma_rx_channel = NULL;
1195 err_no_rxchan:
1196 	return err;
1197 }
1198 
1199 static void terminate_dma(struct pl022 *pl022)
1200 {
1201 	struct dma_chan *rxchan = pl022->dma_rx_channel;
1202 	struct dma_chan *txchan = pl022->dma_tx_channel;
1203 
1204 	dmaengine_terminate_all(rxchan);
1205 	dmaengine_terminate_all(txchan);
1206 	unmap_free_dma_scatter(pl022);
1207 	pl022->dma_running = false;
1208 }
1209 
1210 static void pl022_dma_remove(struct pl022 *pl022)
1211 {
1212 	if (pl022->dma_running)
1213 		terminate_dma(pl022);
1214 	if (pl022->dma_tx_channel)
1215 		dma_release_channel(pl022->dma_tx_channel);
1216 	if (pl022->dma_rx_channel)
1217 		dma_release_channel(pl022->dma_rx_channel);
1218 	kfree(pl022->dummypage);
1219 }
1220 
1221 #else
1222 static inline int configure_dma(struct pl022 *pl022)
1223 {
1224 	return -ENODEV;
1225 }
1226 
1227 static inline int pl022_dma_autoprobe(struct pl022 *pl022)
1228 {
1229 	return 0;
1230 }
1231 
1232 static inline int pl022_dma_probe(struct pl022 *pl022)
1233 {
1234 	return 0;
1235 }
1236 
1237 static inline void pl022_dma_remove(struct pl022 *pl022)
1238 {
1239 }
1240 #endif
1241 
1242 /**
1243  * pl022_interrupt_handler - Interrupt handler for SSP controller
1244  * @irq: IRQ number
1245  * @dev_id: Local device data
1246  *
1247  * This function handles interrupts generated for an interrupt based transfer.
1248  * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1249  * current message's state as STATE_ERROR and schedule the tasklet
1250  * pump_transfers which will do the postprocessing of the current message by
1251  * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1252  * more data, and writes data in TX FIFO till it is not full. If we complete
1253  * the transfer we move to the next transfer and schedule the tasklet.
1254  */
1255 static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1256 {
1257 	struct pl022 *pl022 = dev_id;
1258 	struct spi_message *msg = pl022->cur_msg;
1259 	u16 irq_status = 0;
1260 
1261 	if (unlikely(!msg)) {
1262 		dev_err(&pl022->adev->dev,
1263 			"bad message state in interrupt handler");
1264 		/* Never fail */
1265 		return IRQ_HANDLED;
1266 	}
1267 
1268 	/* Read the Interrupt Status Register */
1269 	irq_status = readw(SSP_MIS(pl022->virtbase));
1270 
1271 	if (unlikely(!irq_status))
1272 		return IRQ_NONE;
1273 
1274 	/*
1275 	 * This handles the FIFO interrupts, the timeout
1276 	 * interrupts are flatly ignored, they cannot be
1277 	 * trusted.
1278 	 */
1279 	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1280 		/*
1281 		 * Overrun interrupt - bail out since our Data has been
1282 		 * corrupted
1283 		 */
1284 		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1285 		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1286 			dev_err(&pl022->adev->dev,
1287 				"RXFIFO is full\n");
1288 
1289 		/*
1290 		 * Disable and clear interrupts, disable SSP,
1291 		 * mark message with bad status so it can be
1292 		 * retried.
1293 		 */
1294 		writew(DISABLE_ALL_INTERRUPTS,
1295 		       SSP_IMSC(pl022->virtbase));
1296 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1297 		writew((readw(SSP_CR1(pl022->virtbase)) &
1298 			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1299 		msg->state = STATE_ERROR;
1300 
1301 		/* Schedule message queue handler */
1302 		tasklet_schedule(&pl022->pump_transfers);
1303 		return IRQ_HANDLED;
1304 	}
1305 
1306 	readwriter(pl022);
1307 
1308 	if (pl022->tx == pl022->tx_end) {
1309 		/* Disable Transmit interrupt, enable receive interrupt */
1310 		writew((readw(SSP_IMSC(pl022->virtbase)) &
1311 		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1312 		       SSP_IMSC(pl022->virtbase));
1313 	}
1314 
1315 	/*
1316 	 * Since all transactions must write as much as shall be read,
1317 	 * we can conclude the entire transaction once RX is complete.
1318 	 * At this point, all TX will always be finished.
1319 	 */
1320 	if (pl022->rx >= pl022->rx_end) {
1321 		writew(DISABLE_ALL_INTERRUPTS,
1322 		       SSP_IMSC(pl022->virtbase));
1323 		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1324 		if (unlikely(pl022->rx > pl022->rx_end)) {
1325 			dev_warn(&pl022->adev->dev, "read %u surplus "
1326 				 "bytes (did you request an odd "
1327 				 "number of bytes on a 16bit bus?)\n",
1328 				 (u32) (pl022->rx - pl022->rx_end));
1329 		}
1330 		/* Update total bytes transferred */
1331 		msg->actual_length += pl022->cur_transfer->len;
1332 		/* Move to next transfer */
1333 		msg->state = next_transfer(pl022);
1334 		if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
1335 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1336 		tasklet_schedule(&pl022->pump_transfers);
1337 		return IRQ_HANDLED;
1338 	}
1339 
1340 	return IRQ_HANDLED;
1341 }
1342 
1343 /*
1344  * This sets up the pointers to memory for the next message to
1345  * send out on the SPI bus.
1346  */
1347 static int set_up_next_transfer(struct pl022 *pl022,
1348 				struct spi_transfer *transfer)
1349 {
1350 	int residue;
1351 
1352 	/* Sanity check the message for this bus width */
1353 	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1354 	if (unlikely(residue != 0)) {
1355 		dev_err(&pl022->adev->dev,
1356 			"message of %u bytes to transmit but the current "
1357 			"chip bus has a data width of %u bytes!\n",
1358 			pl022->cur_transfer->len,
1359 			pl022->cur_chip->n_bytes);
1360 		dev_err(&pl022->adev->dev, "skipping this message\n");
1361 		return -EIO;
1362 	}
1363 	pl022->tx = (void *)transfer->tx_buf;
1364 	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1365 	pl022->rx = (void *)transfer->rx_buf;
1366 	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1367 	pl022->write =
1368 	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1369 	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1370 	return 0;
1371 }
1372 
1373 /**
1374  * pump_transfers - Tasklet function which schedules next transfer
1375  * when running in interrupt or DMA transfer mode.
1376  * @data: SSP driver private data structure
1377  *
1378  */
1379 static void pump_transfers(unsigned long data)
1380 {
1381 	struct pl022 *pl022 = (struct pl022 *) data;
1382 	struct spi_message *message = NULL;
1383 	struct spi_transfer *transfer = NULL;
1384 	struct spi_transfer *previous = NULL;
1385 
1386 	/* Get current state information */
1387 	message = pl022->cur_msg;
1388 	transfer = pl022->cur_transfer;
1389 
1390 	/* Handle for abort */
1391 	if (message->state == STATE_ERROR) {
1392 		message->status = -EIO;
1393 		giveback(pl022);
1394 		return;
1395 	}
1396 
1397 	/* Handle end of message */
1398 	if (message->state == STATE_DONE) {
1399 		message->status = 0;
1400 		giveback(pl022);
1401 		return;
1402 	}
1403 
1404 	/* Delay if requested at end of transfer before CS change */
1405 	if (message->state == STATE_RUNNING) {
1406 		previous = list_entry(transfer->transfer_list.prev,
1407 					struct spi_transfer,
1408 					transfer_list);
1409 		/*
1410 		 * FIXME: This runs in interrupt context.
1411 		 * Is this really smart?
1412 		 */
1413 		spi_transfer_delay_exec(previous);
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 print_current_status(struct pl022 *pl022)
1484 {
1485 	u32 read_cr0;
1486 	u16 read_cr1, read_dmacr, read_sr;
1487 
1488 	if (pl022->vendor->extended_cr)
1489 		read_cr0 = readl(SSP_CR0(pl022->virtbase));
1490 	else
1491 		read_cr0 = readw(SSP_CR0(pl022->virtbase));
1492 	read_cr1 = readw(SSP_CR1(pl022->virtbase));
1493 	read_dmacr = readw(SSP_DMACR(pl022->virtbase));
1494 	read_sr = readw(SSP_SR(pl022->virtbase));
1495 
1496 	dev_warn(&pl022->adev->dev, "spi-pl022 CR0: %x\n", read_cr0);
1497 	dev_warn(&pl022->adev->dev, "spi-pl022 CR1: %x\n", read_cr1);
1498 	dev_warn(&pl022->adev->dev, "spi-pl022 DMACR: %x\n", read_dmacr);
1499 	dev_warn(&pl022->adev->dev, "spi-pl022 SR: %x\n", read_sr);
1500 	dev_warn(&pl022->adev->dev,
1501 			"spi-pl022 exp_fifo_level/fifodepth: %u/%d\n",
1502 			pl022->exp_fifo_level,
1503 			pl022->vendor->fifodepth);
1504 
1505 }
1506 
1507 static void do_polling_transfer(struct pl022 *pl022)
1508 {
1509 	struct spi_message *message = NULL;
1510 	struct spi_transfer *transfer = NULL;
1511 	struct spi_transfer *previous = NULL;
1512 	unsigned long time, timeout;
1513 
1514 	message = pl022->cur_msg;
1515 
1516 	while (message->state != STATE_DONE) {
1517 		/* Handle for abort */
1518 		if (message->state == STATE_ERROR)
1519 			break;
1520 		transfer = pl022->cur_transfer;
1521 
1522 		/* Delay if requested at end of transfer */
1523 		if (message->state == STATE_RUNNING) {
1524 			previous =
1525 			    list_entry(transfer->transfer_list.prev,
1526 				       struct spi_transfer, transfer_list);
1527 			spi_transfer_delay_exec(previous);
1528 			if (previous->cs_change)
1529 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1530 		} else {
1531 			/* STATE_START */
1532 			message->state = STATE_RUNNING;
1533 			if (!pl022->next_msg_cs_active)
1534 				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1535 		}
1536 
1537 		/* Configuration Changing Per Transfer */
1538 		if (set_up_next_transfer(pl022, transfer)) {
1539 			/* Error path */
1540 			message->state = STATE_ERROR;
1541 			break;
1542 		}
1543 		/* Flush FIFOs and enable SSP */
1544 		flush(pl022);
1545 		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1546 		       SSP_CR1(pl022->virtbase));
1547 
1548 		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1549 
1550 		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1551 		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1552 			time = jiffies;
1553 			readwriter(pl022);
1554 			if (time_after(time, timeout)) {
1555 				dev_warn(&pl022->adev->dev,
1556 				"%s: timeout!\n", __func__);
1557 				message->state = STATE_TIMEOUT;
1558 				print_current_status(pl022);
1559 				goto out;
1560 			}
1561 			cpu_relax();
1562 		}
1563 
1564 		/* Update total byte transferred */
1565 		message->actual_length += pl022->cur_transfer->len;
1566 		/* Move to next transfer */
1567 		message->state = next_transfer(pl022);
1568 		if (message->state != STATE_DONE
1569 		    && pl022->cur_transfer->cs_change)
1570 			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1571 	}
1572 out:
1573 	/* Handle end of message */
1574 	if (message->state == STATE_DONE)
1575 		message->status = 0;
1576 	else if (message->state == STATE_TIMEOUT)
1577 		message->status = -EAGAIN;
1578 	else
1579 		message->status = -EIO;
1580 
1581 	giveback(pl022);
1582 	return;
1583 }
1584 
1585 static int pl022_transfer_one_message(struct spi_master *master,
1586 				      struct spi_message *msg)
1587 {
1588 	struct pl022 *pl022 = spi_master_get_devdata(master);
1589 
1590 	/* Initial message state */
1591 	pl022->cur_msg = msg;
1592 	msg->state = STATE_START;
1593 
1594 	pl022->cur_transfer = list_entry(msg->transfers.next,
1595 					 struct spi_transfer, transfer_list);
1596 
1597 	/* Setup the SPI using the per chip configuration */
1598 	pl022->cur_chip = spi_get_ctldata(msg->spi);
1599 	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1600 
1601 	restore_state(pl022);
1602 	flush(pl022);
1603 
1604 	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1605 		do_polling_transfer(pl022);
1606 	else
1607 		do_interrupt_dma_transfer(pl022);
1608 
1609 	return 0;
1610 }
1611 
1612 static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1613 {
1614 	struct pl022 *pl022 = spi_master_get_devdata(master);
1615 
1616 	/* nothing more to do - disable spi/ssp and power off */
1617 	writew((readw(SSP_CR1(pl022->virtbase)) &
1618 		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1619 
1620 	return 0;
1621 }
1622 
1623 static int verify_controller_parameters(struct pl022 *pl022,
1624 				struct pl022_config_chip const *chip_info)
1625 {
1626 	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1627 	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1628 		dev_err(&pl022->adev->dev,
1629 			"interface is configured incorrectly\n");
1630 		return -EINVAL;
1631 	}
1632 	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1633 	    (!pl022->vendor->unidir)) {
1634 		dev_err(&pl022->adev->dev,
1635 			"unidirectional mode not supported in this "
1636 			"hardware version\n");
1637 		return -EINVAL;
1638 	}
1639 	if ((chip_info->hierarchy != SSP_MASTER)
1640 	    && (chip_info->hierarchy != SSP_SLAVE)) {
1641 		dev_err(&pl022->adev->dev,
1642 			"hierarchy is configured incorrectly\n");
1643 		return -EINVAL;
1644 	}
1645 	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1646 	    && (chip_info->com_mode != DMA_TRANSFER)
1647 	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1648 		dev_err(&pl022->adev->dev,
1649 			"Communication mode is configured incorrectly\n");
1650 		return -EINVAL;
1651 	}
1652 	switch (chip_info->rx_lev_trig) {
1653 	case SSP_RX_1_OR_MORE_ELEM:
1654 	case SSP_RX_4_OR_MORE_ELEM:
1655 	case SSP_RX_8_OR_MORE_ELEM:
1656 		/* These are always OK, all variants can handle this */
1657 		break;
1658 	case SSP_RX_16_OR_MORE_ELEM:
1659 		if (pl022->vendor->fifodepth < 16) {
1660 			dev_err(&pl022->adev->dev,
1661 			"RX FIFO Trigger Level is configured incorrectly\n");
1662 			return -EINVAL;
1663 		}
1664 		break;
1665 	case SSP_RX_32_OR_MORE_ELEM:
1666 		if (pl022->vendor->fifodepth < 32) {
1667 			dev_err(&pl022->adev->dev,
1668 			"RX FIFO Trigger Level is configured incorrectly\n");
1669 			return -EINVAL;
1670 		}
1671 		break;
1672 	default:
1673 		dev_err(&pl022->adev->dev,
1674 			"RX FIFO Trigger Level is configured incorrectly\n");
1675 		return -EINVAL;
1676 	}
1677 	switch (chip_info->tx_lev_trig) {
1678 	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1679 	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1680 	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1681 		/* These are always OK, all variants can handle this */
1682 		break;
1683 	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1684 		if (pl022->vendor->fifodepth < 16) {
1685 			dev_err(&pl022->adev->dev,
1686 			"TX FIFO Trigger Level is configured incorrectly\n");
1687 			return -EINVAL;
1688 		}
1689 		break;
1690 	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1691 		if (pl022->vendor->fifodepth < 32) {
1692 			dev_err(&pl022->adev->dev,
1693 			"TX FIFO Trigger Level is configured incorrectly\n");
1694 			return -EINVAL;
1695 		}
1696 		break;
1697 	default:
1698 		dev_err(&pl022->adev->dev,
1699 			"TX FIFO Trigger Level is configured incorrectly\n");
1700 		return -EINVAL;
1701 	}
1702 	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1703 		if ((chip_info->ctrl_len < SSP_BITS_4)
1704 		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1705 			dev_err(&pl022->adev->dev,
1706 				"CTRL LEN is configured incorrectly\n");
1707 			return -EINVAL;
1708 		}
1709 		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1710 		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1711 			dev_err(&pl022->adev->dev,
1712 				"Wait State is configured incorrectly\n");
1713 			return -EINVAL;
1714 		}
1715 		/* Half duplex is only available in the ST Micro version */
1716 		if (pl022->vendor->extended_cr) {
1717 			if ((chip_info->duplex !=
1718 			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1719 			    && (chip_info->duplex !=
1720 				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1721 				dev_err(&pl022->adev->dev,
1722 					"Microwire duplex mode is configured incorrectly\n");
1723 				return -EINVAL;
1724 			}
1725 		} else {
1726 			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1727 				dev_err(&pl022->adev->dev,
1728 					"Microwire half duplex mode requested,"
1729 					" but this is only available in the"
1730 					" ST version of PL022\n");
1731 			return -EINVAL;
1732 		}
1733 	}
1734 	return 0;
1735 }
1736 
1737 static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1738 {
1739 	return rate / (cpsdvsr * (1 + scr));
1740 }
1741 
1742 static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1743 				    ssp_clock_params * clk_freq)
1744 {
1745 	/* Lets calculate the frequency parameters */
1746 	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1747 	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1748 		best_scr = 0, tmp, found = 0;
1749 
1750 	rate = clk_get_rate(pl022->clk);
1751 	/* cpsdvscr = 2 & scr 0 */
1752 	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1753 	/* cpsdvsr = 254 & scr = 255 */
1754 	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1755 
1756 	if (freq > max_tclk)
1757 		dev_warn(&pl022->adev->dev,
1758 			"Max speed that can be programmed is %d Hz, you requested %d\n",
1759 			max_tclk, freq);
1760 
1761 	if (freq < min_tclk) {
1762 		dev_err(&pl022->adev->dev,
1763 			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1764 			freq, min_tclk);
1765 		return -EINVAL;
1766 	}
1767 
1768 	/*
1769 	 * best_freq will give closest possible available rate (<= requested
1770 	 * freq) for all values of scr & cpsdvsr.
1771 	 */
1772 	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1773 		while (scr <= SCR_MAX) {
1774 			tmp = spi_rate(rate, cpsdvsr, scr);
1775 
1776 			if (tmp > freq) {
1777 				/* we need lower freq */
1778 				scr++;
1779 				continue;
1780 			}
1781 
1782 			/*
1783 			 * If found exact value, mark found and break.
1784 			 * If found more closer value, update and break.
1785 			 */
1786 			if (tmp > best_freq) {
1787 				best_freq = tmp;
1788 				best_cpsdvsr = cpsdvsr;
1789 				best_scr = scr;
1790 
1791 				if (tmp == freq)
1792 					found = 1;
1793 			}
1794 			/*
1795 			 * increased scr will give lower rates, which are not
1796 			 * required
1797 			 */
1798 			break;
1799 		}
1800 		cpsdvsr += 2;
1801 		scr = SCR_MIN;
1802 	}
1803 
1804 	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1805 			freq);
1806 
1807 	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1808 	clk_freq->scr = (u8) (best_scr & 0xFF);
1809 	dev_dbg(&pl022->adev->dev,
1810 		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1811 		freq, best_freq);
1812 	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1813 		clk_freq->cpsdvsr, clk_freq->scr);
1814 
1815 	return 0;
1816 }
1817 
1818 /*
1819  * A piece of default chip info unless the platform
1820  * supplies it.
1821  */
1822 static const struct pl022_config_chip pl022_default_chip_info = {
1823 	.com_mode = POLLING_TRANSFER,
1824 	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1825 	.hierarchy = SSP_SLAVE,
1826 	.slave_tx_disable = DO_NOT_DRIVE_TX,
1827 	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1828 	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1829 	.ctrl_len = SSP_BITS_8,
1830 	.wait_state = SSP_MWIRE_WAIT_ZERO,
1831 	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1832 	.cs_control = null_cs_control,
1833 };
1834 
1835 /**
1836  * pl022_setup - setup function registered to SPI master framework
1837  * @spi: spi device which is requesting setup
1838  *
1839  * This function is registered to the SPI framework for this SPI master
1840  * controller. If it is the first time when setup is called by this device,
1841  * this function will initialize the runtime state for this chip and save
1842  * the same in the device structure. Else it will update the runtime info
1843  * with the updated chip info. Nothing is really being written to the
1844  * controller hardware here, that is not done until the actual transfer
1845  * commence.
1846  */
1847 static int pl022_setup(struct spi_device *spi)
1848 {
1849 	struct pl022_config_chip const *chip_info;
1850 	struct pl022_config_chip chip_info_dt;
1851 	struct chip_data *chip;
1852 	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1853 	int status = 0;
1854 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1855 	unsigned int bits = spi->bits_per_word;
1856 	u32 tmp;
1857 	struct device_node *np = spi->dev.of_node;
1858 
1859 	if (!spi->max_speed_hz)
1860 		return -EINVAL;
1861 
1862 	/* Get controller_state if one is supplied */
1863 	chip = spi_get_ctldata(spi);
1864 
1865 	if (chip == NULL) {
1866 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1867 		if (!chip)
1868 			return -ENOMEM;
1869 		dev_dbg(&spi->dev,
1870 			"allocated memory for controller's runtime state\n");
1871 	}
1872 
1873 	/* Get controller data if one is supplied */
1874 	chip_info = spi->controller_data;
1875 
1876 	if (chip_info == NULL) {
1877 		if (np) {
1878 			chip_info_dt = pl022_default_chip_info;
1879 
1880 			chip_info_dt.hierarchy = SSP_MASTER;
1881 			of_property_read_u32(np, "pl022,interface",
1882 				&chip_info_dt.iface);
1883 			of_property_read_u32(np, "pl022,com-mode",
1884 				&chip_info_dt.com_mode);
1885 			of_property_read_u32(np, "pl022,rx-level-trig",
1886 				&chip_info_dt.rx_lev_trig);
1887 			of_property_read_u32(np, "pl022,tx-level-trig",
1888 				&chip_info_dt.tx_lev_trig);
1889 			of_property_read_u32(np, "pl022,ctrl-len",
1890 				&chip_info_dt.ctrl_len);
1891 			of_property_read_u32(np, "pl022,wait-state",
1892 				&chip_info_dt.wait_state);
1893 			of_property_read_u32(np, "pl022,duplex",
1894 				&chip_info_dt.duplex);
1895 
1896 			chip_info = &chip_info_dt;
1897 		} else {
1898 			chip_info = &pl022_default_chip_info;
1899 			/* spi_board_info.controller_data not is supplied */
1900 			dev_dbg(&spi->dev,
1901 				"using default controller_data settings\n");
1902 		}
1903 	} else
1904 		dev_dbg(&spi->dev,
1905 			"using user supplied controller_data settings\n");
1906 
1907 	/*
1908 	 * We can override with custom divisors, else we use the board
1909 	 * frequency setting
1910 	 */
1911 	if ((0 == chip_info->clk_freq.cpsdvsr)
1912 	    && (0 == chip_info->clk_freq.scr)) {
1913 		status = calculate_effective_freq(pl022,
1914 						  spi->max_speed_hz,
1915 						  &clk_freq);
1916 		if (status < 0)
1917 			goto err_config_params;
1918 	} else {
1919 		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1920 		if ((clk_freq.cpsdvsr % 2) != 0)
1921 			clk_freq.cpsdvsr =
1922 				clk_freq.cpsdvsr - 1;
1923 	}
1924 	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1925 	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1926 		status = -EINVAL;
1927 		dev_err(&spi->dev,
1928 			"cpsdvsr is configured incorrectly\n");
1929 		goto err_config_params;
1930 	}
1931 
1932 	status = verify_controller_parameters(pl022, chip_info);
1933 	if (status) {
1934 		dev_err(&spi->dev, "controller data is incorrect");
1935 		goto err_config_params;
1936 	}
1937 
1938 	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1939 	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1940 
1941 	/* Now set controller state based on controller data */
1942 	chip->xfer_type = chip_info->com_mode;
1943 	if (!chip_info->cs_control) {
1944 		chip->cs_control = null_cs_control;
1945 		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1946 			dev_warn(&spi->dev,
1947 				 "invalid chip select\n");
1948 	} else
1949 		chip->cs_control = chip_info->cs_control;
1950 
1951 	/* Check bits per word with vendor specific range */
1952 	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1953 		status = -ENOTSUPP;
1954 		dev_err(&spi->dev, "illegal data size for this controller!\n");
1955 		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1956 				pl022->vendor->max_bpw);
1957 		goto err_config_params;
1958 	} else if (bits <= 8) {
1959 		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1960 		chip->n_bytes = 1;
1961 		chip->read = READING_U8;
1962 		chip->write = WRITING_U8;
1963 	} else if (bits <= 16) {
1964 		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1965 		chip->n_bytes = 2;
1966 		chip->read = READING_U16;
1967 		chip->write = WRITING_U16;
1968 	} else {
1969 		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1970 		chip->n_bytes = 4;
1971 		chip->read = READING_U32;
1972 		chip->write = WRITING_U32;
1973 	}
1974 
1975 	/* Now Initialize all register settings required for this chip */
1976 	chip->cr0 = 0;
1977 	chip->cr1 = 0;
1978 	chip->dmacr = 0;
1979 	chip->cpsr = 0;
1980 	if ((chip_info->com_mode == DMA_TRANSFER)
1981 	    && ((pl022->master_info)->enable_dma)) {
1982 		chip->enable_dma = true;
1983 		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1984 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1985 			       SSP_DMACR_MASK_RXDMAE, 0);
1986 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1987 			       SSP_DMACR_MASK_TXDMAE, 1);
1988 	} else {
1989 		chip->enable_dma = false;
1990 		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1991 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1992 			       SSP_DMACR_MASK_RXDMAE, 0);
1993 		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1994 			       SSP_DMACR_MASK_TXDMAE, 1);
1995 	}
1996 
1997 	chip->cpsr = clk_freq.cpsdvsr;
1998 
1999 	/* Special setup for the ST micro extended control registers */
2000 	if (pl022->vendor->extended_cr) {
2001 		u32 etx;
2002 
2003 		if (pl022->vendor->pl023) {
2004 			/* These bits are only in the PL023 */
2005 			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
2006 				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
2007 		} else {
2008 			/* These bits are in the PL022 but not PL023 */
2009 			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
2010 				       SSP_CR0_MASK_HALFDUP_ST, 5);
2011 			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
2012 				       SSP_CR0_MASK_CSS_ST, 16);
2013 			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2014 				       SSP_CR0_MASK_FRF_ST, 21);
2015 			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
2016 				       SSP_CR1_MASK_MWAIT_ST, 6);
2017 		}
2018 		SSP_WRITE_BITS(chip->cr0, bits - 1,
2019 			       SSP_CR0_MASK_DSS_ST, 0);
2020 
2021 		if (spi->mode & SPI_LSB_FIRST) {
2022 			tmp = SSP_RX_LSB;
2023 			etx = SSP_TX_LSB;
2024 		} else {
2025 			tmp = SSP_RX_MSB;
2026 			etx = SSP_TX_MSB;
2027 		}
2028 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
2029 		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
2030 		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
2031 			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
2032 		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
2033 			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
2034 	} else {
2035 		SSP_WRITE_BITS(chip->cr0, bits - 1,
2036 			       SSP_CR0_MASK_DSS, 0);
2037 		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2038 			       SSP_CR0_MASK_FRF, 4);
2039 	}
2040 
2041 	/* Stuff that is common for all versions */
2042 	if (spi->mode & SPI_CPOL)
2043 		tmp = SSP_CLK_POL_IDLE_HIGH;
2044 	else
2045 		tmp = SSP_CLK_POL_IDLE_LOW;
2046 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
2047 
2048 	if (spi->mode & SPI_CPHA)
2049 		tmp = SSP_CLK_SECOND_EDGE;
2050 	else
2051 		tmp = SSP_CLK_FIRST_EDGE;
2052 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
2053 
2054 	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
2055 	/* Loopback is available on all versions except PL023 */
2056 	if (pl022->vendor->loopback) {
2057 		if (spi->mode & SPI_LOOP)
2058 			tmp = LOOPBACK_ENABLED;
2059 		else
2060 			tmp = LOOPBACK_DISABLED;
2061 		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2062 	}
2063 	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2064 	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2065 	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2066 		3);
2067 
2068 	/* Save controller_state */
2069 	spi_set_ctldata(spi, chip);
2070 	return status;
2071  err_config_params:
2072 	spi_set_ctldata(spi, NULL);
2073 	kfree(chip);
2074 	return status;
2075 }
2076 
2077 /**
2078  * pl022_cleanup - cleanup function registered to SPI master framework
2079  * @spi: spi device which is requesting cleanup
2080  *
2081  * This function is registered to the SPI framework for this SPI master
2082  * controller. It will free the runtime state of chip.
2083  */
2084 static void pl022_cleanup(struct spi_device *spi)
2085 {
2086 	struct chip_data *chip = spi_get_ctldata(spi);
2087 
2088 	spi_set_ctldata(spi, NULL);
2089 	kfree(chip);
2090 }
2091 
2092 static struct pl022_ssp_controller *
2093 pl022_platform_data_dt_get(struct device *dev)
2094 {
2095 	struct device_node *np = dev->of_node;
2096 	struct pl022_ssp_controller *pd;
2097 	u32 tmp = 0;
2098 
2099 	if (!np) {
2100 		dev_err(dev, "no dt node defined\n");
2101 		return NULL;
2102 	}
2103 
2104 	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2105 	if (!pd)
2106 		return NULL;
2107 
2108 	pd->bus_id = -1;
2109 	pd->enable_dma = 1;
2110 	of_property_read_u32(np, "num-cs", &tmp);
2111 	pd->num_chipselect = tmp;
2112 	of_property_read_u32(np, "pl022,autosuspend-delay",
2113 			     &pd->autosuspend_delay);
2114 	pd->rt = of_property_read_bool(np, "pl022,rt");
2115 
2116 	return pd;
2117 }
2118 
2119 static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2120 {
2121 	struct device *dev = &adev->dev;
2122 	struct pl022_ssp_controller *platform_info =
2123 			dev_get_platdata(&adev->dev);
2124 	struct spi_master *master;
2125 	struct pl022 *pl022 = NULL;	/*Data for this driver */
2126 	struct device_node *np = adev->dev.of_node;
2127 	int status = 0, i, num_cs;
2128 
2129 	dev_info(&adev->dev,
2130 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2131 	if (!platform_info && IS_ENABLED(CONFIG_OF))
2132 		platform_info = pl022_platform_data_dt_get(dev);
2133 
2134 	if (!platform_info) {
2135 		dev_err(dev, "probe: no platform data defined\n");
2136 		return -ENODEV;
2137 	}
2138 
2139 	if (platform_info->num_chipselect) {
2140 		num_cs = platform_info->num_chipselect;
2141 	} else {
2142 		dev_err(dev, "probe: no chip select defined\n");
2143 		return -ENODEV;
2144 	}
2145 
2146 	/* Allocate master with space for data */
2147 	master = spi_alloc_master(dev, sizeof(struct pl022));
2148 	if (master == NULL) {
2149 		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2150 		return -ENOMEM;
2151 	}
2152 
2153 	pl022 = spi_master_get_devdata(master);
2154 	pl022->master = master;
2155 	pl022->master_info = platform_info;
2156 	pl022->adev = adev;
2157 	pl022->vendor = id->data;
2158 	pl022->chipselects = devm_kcalloc(dev, num_cs, sizeof(int),
2159 					  GFP_KERNEL);
2160 	if (!pl022->chipselects) {
2161 		status = -ENOMEM;
2162 		goto err_no_mem;
2163 	}
2164 
2165 	/*
2166 	 * Bus Number Which has been Assigned to this SSP controller
2167 	 * on this board
2168 	 */
2169 	master->bus_num = platform_info->bus_id;
2170 	master->num_chipselect = num_cs;
2171 	master->cleanup = pl022_cleanup;
2172 	master->setup = pl022_setup;
2173 	master->auto_runtime_pm = true;
2174 	master->transfer_one_message = pl022_transfer_one_message;
2175 	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2176 	master->rt = platform_info->rt;
2177 	master->dev.of_node = dev->of_node;
2178 
2179 	if (platform_info->num_chipselect && platform_info->chipselects) {
2180 		for (i = 0; i < num_cs; i++)
2181 			pl022->chipselects[i] = platform_info->chipselects[i];
2182 	} else if (pl022->vendor->internal_cs_ctrl) {
2183 		for (i = 0; i < num_cs; i++)
2184 			pl022->chipselects[i] = i;
2185 	} else if (IS_ENABLED(CONFIG_OF)) {
2186 		for (i = 0; i < num_cs; i++) {
2187 			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2188 
2189 			if (cs_gpio == -EPROBE_DEFER) {
2190 				status = -EPROBE_DEFER;
2191 				goto err_no_gpio;
2192 			}
2193 
2194 			pl022->chipselects[i] = cs_gpio;
2195 
2196 			if (gpio_is_valid(cs_gpio)) {
2197 				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2198 					dev_err(&adev->dev,
2199 						"could not request %d gpio\n",
2200 						cs_gpio);
2201 				else if (gpio_direction_output(cs_gpio, 1))
2202 					dev_err(&adev->dev,
2203 						"could not set gpio %d as output\n",
2204 						cs_gpio);
2205 			}
2206 		}
2207 	}
2208 
2209 	/*
2210 	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2211 	 * always MS bit first on the original pl022.
2212 	 */
2213 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2214 	if (pl022->vendor->extended_cr)
2215 		master->mode_bits |= SPI_LSB_FIRST;
2216 
2217 	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2218 
2219 	status = amba_request_regions(adev, NULL);
2220 	if (status)
2221 		goto err_no_ioregion;
2222 
2223 	pl022->phybase = adev->res.start;
2224 	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2225 				       resource_size(&adev->res));
2226 	if (pl022->virtbase == NULL) {
2227 		status = -ENOMEM;
2228 		goto err_no_ioremap;
2229 	}
2230 	dev_info(&adev->dev, "mapped registers from %pa to %p\n",
2231 		&adev->res.start, pl022->virtbase);
2232 
2233 	pl022->clk = devm_clk_get(&adev->dev, NULL);
2234 	if (IS_ERR(pl022->clk)) {
2235 		status = PTR_ERR(pl022->clk);
2236 		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2237 		goto err_no_clk;
2238 	}
2239 
2240 	status = clk_prepare_enable(pl022->clk);
2241 	if (status) {
2242 		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2243 		goto err_no_clk_en;
2244 	}
2245 
2246 	/* Initialize transfer pump */
2247 	tasklet_init(&pl022->pump_transfers, pump_transfers,
2248 		     (unsigned long)pl022);
2249 
2250 	/* Disable SSP */
2251 	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2252 	       SSP_CR1(pl022->virtbase));
2253 	load_ssp_default_config(pl022);
2254 
2255 	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2256 				  0, "pl022", pl022);
2257 	if (status < 0) {
2258 		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2259 		goto err_no_irq;
2260 	}
2261 
2262 	/* Get DMA channels, try autoconfiguration first */
2263 	status = pl022_dma_autoprobe(pl022);
2264 	if (status == -EPROBE_DEFER) {
2265 		dev_dbg(dev, "deferring probe to get DMA channel\n");
2266 		goto err_no_irq;
2267 	}
2268 
2269 	/* If that failed, use channels from platform_info */
2270 	if (status == 0)
2271 		platform_info->enable_dma = 1;
2272 	else if (platform_info->enable_dma) {
2273 		status = pl022_dma_probe(pl022);
2274 		if (status != 0)
2275 			platform_info->enable_dma = 0;
2276 	}
2277 
2278 	/* Register with the SPI framework */
2279 	amba_set_drvdata(adev, pl022);
2280 	status = devm_spi_register_master(&adev->dev, master);
2281 	if (status != 0) {
2282 		dev_err(&adev->dev,
2283 			"probe - problem registering spi master\n");
2284 		goto err_spi_register;
2285 	}
2286 	dev_dbg(dev, "probe succeeded\n");
2287 
2288 	/* let runtime pm put suspend */
2289 	if (platform_info->autosuspend_delay > 0) {
2290 		dev_info(&adev->dev,
2291 			"will use autosuspend for runtime pm, delay %dms\n",
2292 			platform_info->autosuspend_delay);
2293 		pm_runtime_set_autosuspend_delay(dev,
2294 			platform_info->autosuspend_delay);
2295 		pm_runtime_use_autosuspend(dev);
2296 	}
2297 	pm_runtime_put(dev);
2298 
2299 	return 0;
2300 
2301  err_spi_register:
2302 	if (platform_info->enable_dma)
2303 		pl022_dma_remove(pl022);
2304  err_no_irq:
2305 	clk_disable_unprepare(pl022->clk);
2306  err_no_clk_en:
2307  err_no_clk:
2308  err_no_ioremap:
2309 	amba_release_regions(adev);
2310  err_no_ioregion:
2311  err_no_gpio:
2312  err_no_mem:
2313 	spi_master_put(master);
2314 	return status;
2315 }
2316 
2317 static void
2318 pl022_remove(struct amba_device *adev)
2319 {
2320 	struct pl022 *pl022 = amba_get_drvdata(adev);
2321 
2322 	if (!pl022)
2323 		return;
2324 
2325 	/*
2326 	 * undo pm_runtime_put() in probe.  I assume that we're not
2327 	 * accessing the primecell here.
2328 	 */
2329 	pm_runtime_get_noresume(&adev->dev);
2330 
2331 	load_ssp_default_config(pl022);
2332 	if (pl022->master_info->enable_dma)
2333 		pl022_dma_remove(pl022);
2334 
2335 	clk_disable_unprepare(pl022->clk);
2336 	amba_release_regions(adev);
2337 	tasklet_disable(&pl022->pump_transfers);
2338 }
2339 
2340 #ifdef CONFIG_PM_SLEEP
2341 static int pl022_suspend(struct device *dev)
2342 {
2343 	struct pl022 *pl022 = dev_get_drvdata(dev);
2344 	int ret;
2345 
2346 	ret = spi_master_suspend(pl022->master);
2347 	if (ret)
2348 		return ret;
2349 
2350 	ret = pm_runtime_force_suspend(dev);
2351 	if (ret) {
2352 		spi_master_resume(pl022->master);
2353 		return ret;
2354 	}
2355 
2356 	pinctrl_pm_select_sleep_state(dev);
2357 
2358 	dev_dbg(dev, "suspended\n");
2359 	return 0;
2360 }
2361 
2362 static int pl022_resume(struct device *dev)
2363 {
2364 	struct pl022 *pl022 = dev_get_drvdata(dev);
2365 	int ret;
2366 
2367 	ret = pm_runtime_force_resume(dev);
2368 	if (ret)
2369 		dev_err(dev, "problem resuming\n");
2370 
2371 	/* Start the queue running */
2372 	ret = spi_master_resume(pl022->master);
2373 	if (!ret)
2374 		dev_dbg(dev, "resumed\n");
2375 
2376 	return ret;
2377 }
2378 #endif
2379 
2380 #ifdef CONFIG_PM
2381 static int pl022_runtime_suspend(struct device *dev)
2382 {
2383 	struct pl022 *pl022 = dev_get_drvdata(dev);
2384 
2385 	clk_disable_unprepare(pl022->clk);
2386 	pinctrl_pm_select_idle_state(dev);
2387 
2388 	return 0;
2389 }
2390 
2391 static int pl022_runtime_resume(struct device *dev)
2392 {
2393 	struct pl022 *pl022 = dev_get_drvdata(dev);
2394 
2395 	pinctrl_pm_select_default_state(dev);
2396 	clk_prepare_enable(pl022->clk);
2397 
2398 	return 0;
2399 }
2400 #endif
2401 
2402 static const struct dev_pm_ops pl022_dev_pm_ops = {
2403 	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2404 	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2405 };
2406 
2407 static struct vendor_data vendor_arm = {
2408 	.fifodepth = 8,
2409 	.max_bpw = 16,
2410 	.unidir = false,
2411 	.extended_cr = false,
2412 	.pl023 = false,
2413 	.loopback = true,
2414 	.internal_cs_ctrl = false,
2415 };
2416 
2417 static struct vendor_data vendor_st = {
2418 	.fifodepth = 32,
2419 	.max_bpw = 32,
2420 	.unidir = false,
2421 	.extended_cr = true,
2422 	.pl023 = false,
2423 	.loopback = true,
2424 	.internal_cs_ctrl = false,
2425 };
2426 
2427 static struct vendor_data vendor_st_pl023 = {
2428 	.fifodepth = 32,
2429 	.max_bpw = 32,
2430 	.unidir = false,
2431 	.extended_cr = true,
2432 	.pl023 = true,
2433 	.loopback = false,
2434 	.internal_cs_ctrl = false,
2435 };
2436 
2437 static struct vendor_data vendor_lsi = {
2438 	.fifodepth = 8,
2439 	.max_bpw = 16,
2440 	.unidir = false,
2441 	.extended_cr = false,
2442 	.pl023 = false,
2443 	.loopback = true,
2444 	.internal_cs_ctrl = true,
2445 };
2446 
2447 static const struct amba_id pl022_ids[] = {
2448 	{
2449 		/*
2450 		 * ARM PL022 variant, this has a 16bit wide
2451 		 * and 8 locations deep TX/RX FIFO
2452 		 */
2453 		.id	= 0x00041022,
2454 		.mask	= 0x000fffff,
2455 		.data	= &vendor_arm,
2456 	},
2457 	{
2458 		/*
2459 		 * ST Micro derivative, this has 32bit wide
2460 		 * and 32 locations deep TX/RX FIFO
2461 		 */
2462 		.id	= 0x01080022,
2463 		.mask	= 0xffffffff,
2464 		.data	= &vendor_st,
2465 	},
2466 	{
2467 		/*
2468 		 * ST-Ericsson derivative "PL023" (this is not
2469 		 * an official ARM number), this is a PL022 SSP block
2470 		 * stripped to SPI mode only, it has 32bit wide
2471 		 * and 32 locations deep TX/RX FIFO but no extended
2472 		 * CR0/CR1 register
2473 		 */
2474 		.id	= 0x00080023,
2475 		.mask	= 0xffffffff,
2476 		.data	= &vendor_st_pl023,
2477 	},
2478 	{
2479 		/*
2480 		 * PL022 variant that has a chip select control register whih
2481 		 * allows control of 5 output signals nCS[0:4].
2482 		 */
2483 		.id	= 0x000b6022,
2484 		.mask	= 0x000fffff,
2485 		.data	= &vendor_lsi,
2486 	},
2487 	{ 0, 0 },
2488 };
2489 
2490 MODULE_DEVICE_TABLE(amba, pl022_ids);
2491 
2492 static struct amba_driver pl022_driver = {
2493 	.drv = {
2494 		.name	= "ssp-pl022",
2495 		.pm	= &pl022_dev_pm_ops,
2496 	},
2497 	.id_table	= pl022_ids,
2498 	.probe		= pl022_probe,
2499 	.remove		= pl022_remove,
2500 };
2501 
2502 static int __init pl022_init(void)
2503 {
2504 	return amba_driver_register(&pl022_driver);
2505 }
2506 subsys_initcall(pl022_init);
2507 
2508 static void __exit pl022_exit(void)
2509 {
2510 	amba_driver_unregister(&pl022_driver);
2511 }
2512 module_exit(pl022_exit);
2513 
2514 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2515 MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2516 MODULE_LICENSE("GPL");
2517