Linux Audio

Check our new training course

Loading...
Note: File does not exist in v6.2.
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Intel PCH/PCU SPI flash driver.
  4 *
  5 * Copyright (C) 2016, Intel Corporation
  6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
  7 */
  8
  9#include <linux/err.h>
 10#include <linux/io.h>
 11#include <linux/iopoll.h>
 12#include <linux/module.h>
 13#include <linux/sched.h>
 14#include <linux/sizes.h>
 15#include <linux/mtd/mtd.h>
 16#include <linux/mtd/partitions.h>
 17#include <linux/mtd/spi-nor.h>
 18
 19#include "intel-spi.h"
 20
 21/* Offsets are from @ispi->base */
 22#define BFPREG				0x00
 23
 24#define HSFSTS_CTL			0x04
 25#define HSFSTS_CTL_FSMIE		BIT(31)
 26#define HSFSTS_CTL_FDBC_SHIFT		24
 27#define HSFSTS_CTL_FDBC_MASK		(0x3f << HSFSTS_CTL_FDBC_SHIFT)
 28
 29#define HSFSTS_CTL_FCYCLE_SHIFT		17
 30#define HSFSTS_CTL_FCYCLE_MASK		(0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
 31/* HW sequencer opcodes */
 32#define HSFSTS_CTL_FCYCLE_READ		(0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
 33#define HSFSTS_CTL_FCYCLE_WRITE		(0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
 34#define HSFSTS_CTL_FCYCLE_ERASE		(0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
 35#define HSFSTS_CTL_FCYCLE_ERASE_64K	(0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
 36#define HSFSTS_CTL_FCYCLE_RDID		(0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
 37#define HSFSTS_CTL_FCYCLE_WRSR		(0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
 38#define HSFSTS_CTL_FCYCLE_RDSR		(0x08 << HSFSTS_CTL_FCYCLE_SHIFT)
 39
 40#define HSFSTS_CTL_FGO			BIT(16)
 41#define HSFSTS_CTL_FLOCKDN		BIT(15)
 42#define HSFSTS_CTL_FDV			BIT(14)
 43#define HSFSTS_CTL_SCIP			BIT(5)
 44#define HSFSTS_CTL_AEL			BIT(2)
 45#define HSFSTS_CTL_FCERR		BIT(1)
 46#define HSFSTS_CTL_FDONE		BIT(0)
 47
 48#define FADDR				0x08
 49#define DLOCK				0x0c
 50#define FDATA(n)			(0x10 + ((n) * 4))
 51
 52#define FRACC				0x50
 53
 54#define FREG(n)				(0x54 + ((n) * 4))
 55#define FREG_BASE_MASK			0x3fff
 56#define FREG_LIMIT_SHIFT		16
 57#define FREG_LIMIT_MASK			(0x03fff << FREG_LIMIT_SHIFT)
 58
 59/* Offset is from @ispi->pregs */
 60#define PR(n)				((n) * 4)
 61#define PR_WPE				BIT(31)
 62#define PR_LIMIT_SHIFT			16
 63#define PR_LIMIT_MASK			(0x3fff << PR_LIMIT_SHIFT)
 64#define PR_RPE				BIT(15)
 65#define PR_BASE_MASK			0x3fff
 66
 67/* Offsets are from @ispi->sregs */
 68#define SSFSTS_CTL			0x00
 69#define SSFSTS_CTL_FSMIE		BIT(23)
 70#define SSFSTS_CTL_DS			BIT(22)
 71#define SSFSTS_CTL_DBC_SHIFT		16
 72#define SSFSTS_CTL_SPOP			BIT(11)
 73#define SSFSTS_CTL_ACS			BIT(10)
 74#define SSFSTS_CTL_SCGO			BIT(9)
 75#define SSFSTS_CTL_COP_SHIFT		12
 76#define SSFSTS_CTL_FRS			BIT(7)
 77#define SSFSTS_CTL_DOFRS		BIT(6)
 78#define SSFSTS_CTL_AEL			BIT(4)
 79#define SSFSTS_CTL_FCERR		BIT(3)
 80#define SSFSTS_CTL_FDONE		BIT(2)
 81#define SSFSTS_CTL_SCIP			BIT(0)
 82
 83#define PREOP_OPTYPE			0x04
 84#define OPMENU0				0x08
 85#define OPMENU1				0x0c
 86
 87#define OPTYPE_READ_NO_ADDR		0
 88#define OPTYPE_WRITE_NO_ADDR		1
 89#define OPTYPE_READ_WITH_ADDR		2
 90#define OPTYPE_WRITE_WITH_ADDR		3
 91
 92/* CPU specifics */
 93#define BYT_PR				0x74
 94#define BYT_SSFSTS_CTL			0x90
 95#define BYT_BCR				0xfc
 96#define BYT_BCR_WPD			BIT(0)
 97#define BYT_FREG_NUM			5
 98#define BYT_PR_NUM			5
 99
100#define LPT_PR				0x74
101#define LPT_SSFSTS_CTL			0x90
102#define LPT_FREG_NUM			5
103#define LPT_PR_NUM			5
104
105#define BXT_PR				0x84
106#define BXT_SSFSTS_CTL			0xa0
107#define BXT_FREG_NUM			12
108#define BXT_PR_NUM			6
109
110#define CNL_PR				0x84
111#define CNL_FREG_NUM			6
112#define CNL_PR_NUM			5
113
114#define LVSCC				0xc4
115#define UVSCC				0xc8
116#define ERASE_OPCODE_SHIFT		8
117#define ERASE_OPCODE_MASK		(0xff << ERASE_OPCODE_SHIFT)
118#define ERASE_64K_OPCODE_SHIFT		16
119#define ERASE_64K_OPCODE_MASK		(0xff << ERASE_OPCODE_SHIFT)
120
121#define INTEL_SPI_TIMEOUT		5000 /* ms */
122#define INTEL_SPI_FIFO_SZ		64
123
124/**
125 * struct intel_spi - Driver private data
126 * @dev: Device pointer
127 * @info: Pointer to board specific info
128 * @nor: SPI NOR layer structure
129 * @base: Beginning of MMIO space
130 * @pregs: Start of protection registers
131 * @sregs: Start of software sequencer registers
132 * @nregions: Maximum number of regions
133 * @pr_num: Maximum number of protected range registers
134 * @writeable: Is the chip writeable
135 * @locked: Is SPI setting locked
136 * @swseq_reg: Use SW sequencer in register reads/writes
137 * @swseq_erase: Use SW sequencer in erase operation
138 * @erase_64k: 64k erase supported
139 * @atomic_preopcode: Holds preopcode when atomic sequence is requested
140 * @opcodes: Opcodes which are supported. This are programmed by BIOS
141 *           before it locks down the controller.
142 */
143struct intel_spi {
144	struct device *dev;
145	const struct intel_spi_boardinfo *info;
146	struct spi_nor nor;
147	void __iomem *base;
148	void __iomem *pregs;
149	void __iomem *sregs;
150	size_t nregions;
151	size_t pr_num;
152	bool writeable;
153	bool locked;
154	bool swseq_reg;
155	bool swseq_erase;
156	bool erase_64k;
157	u8 atomic_preopcode;
158	u8 opcodes[8];
159};
160
161static bool writeable;
162module_param(writeable, bool, 0);
163MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
164
165static void intel_spi_dump_regs(struct intel_spi *ispi)
166{
167	u32 value;
168	int i;
169
170	dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));
171
172	value = readl(ispi->base + HSFSTS_CTL);
173	dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
174	if (value & HSFSTS_CTL_FLOCKDN)
175		dev_dbg(ispi->dev, "-> Locked\n");
176
177	dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
178	dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));
179
180	for (i = 0; i < 16; i++)
181		dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
182			i, readl(ispi->base + FDATA(i)));
183
184	dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));
185
186	for (i = 0; i < ispi->nregions; i++)
187		dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
188			readl(ispi->base + FREG(i)));
189	for (i = 0; i < ispi->pr_num; i++)
190		dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
191			readl(ispi->pregs + PR(i)));
192
193	if (ispi->sregs) {
194		value = readl(ispi->sregs + SSFSTS_CTL);
195		dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
196		dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
197			readl(ispi->sregs + PREOP_OPTYPE));
198		dev_dbg(ispi->dev, "OPMENU0=0x%08x\n",
199			readl(ispi->sregs + OPMENU0));
200		dev_dbg(ispi->dev, "OPMENU1=0x%08x\n",
201			readl(ispi->sregs + OPMENU1));
202	}
203
204	if (ispi->info->type == INTEL_SPI_BYT)
205		dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BYT_BCR));
206
207	dev_dbg(ispi->dev, "LVSCC=0x%08x\n", readl(ispi->base + LVSCC));
208	dev_dbg(ispi->dev, "UVSCC=0x%08x\n", readl(ispi->base + UVSCC));
209
210	dev_dbg(ispi->dev, "Protected regions:\n");
211	for (i = 0; i < ispi->pr_num; i++) {
212		u32 base, limit;
213
214		value = readl(ispi->pregs + PR(i));
215		if (!(value & (PR_WPE | PR_RPE)))
216			continue;
217
218		limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
219		base = value & PR_BASE_MASK;
220
221		dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
222			 i, base << 12, (limit << 12) | 0xfff,
223			 value & PR_WPE ? 'W' : '.',
224			 value & PR_RPE ? 'R' : '.');
225	}
226
227	dev_dbg(ispi->dev, "Flash regions:\n");
228	for (i = 0; i < ispi->nregions; i++) {
229		u32 region, base, limit;
230
231		region = readl(ispi->base + FREG(i));
232		base = region & FREG_BASE_MASK;
233		limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
234
235		if (base >= limit || (i > 0 && limit == 0))
236			dev_dbg(ispi->dev, " %02d disabled\n", i);
237		else
238			dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
239				 i, base << 12, (limit << 12) | 0xfff);
240	}
241
242	dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
243		ispi->swseq_reg ? 'S' : 'H');
244	dev_dbg(ispi->dev, "Using %cW sequencer for erase operation\n",
245		ispi->swseq_erase ? 'S' : 'H');
246}
247
248/* Reads max INTEL_SPI_FIFO_SZ bytes from the device fifo */
249static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
250{
251	size_t bytes;
252	int i = 0;
253
254	if (size > INTEL_SPI_FIFO_SZ)
255		return -EINVAL;
256
257	while (size > 0) {
258		bytes = min_t(size_t, size, 4);
259		memcpy_fromio(buf, ispi->base + FDATA(i), bytes);
260		size -= bytes;
261		buf += bytes;
262		i++;
263	}
264
265	return 0;
266}
267
268/* Writes max INTEL_SPI_FIFO_SZ bytes to the device fifo */
269static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
270				 size_t size)
271{
272	size_t bytes;
273	int i = 0;
274
275	if (size > INTEL_SPI_FIFO_SZ)
276		return -EINVAL;
277
278	while (size > 0) {
279		bytes = min_t(size_t, size, 4);
280		memcpy_toio(ispi->base + FDATA(i), buf, bytes);
281		size -= bytes;
282		buf += bytes;
283		i++;
284	}
285
286	return 0;
287}
288
289static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
290{
291	u32 val;
292
293	return readl_poll_timeout(ispi->base + HSFSTS_CTL, val,
294				  !(val & HSFSTS_CTL_SCIP), 0,
295				  INTEL_SPI_TIMEOUT * 1000);
296}
297
298static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
299{
300	u32 val;
301
302	return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val,
303				  !(val & SSFSTS_CTL_SCIP), 0,
304				  INTEL_SPI_TIMEOUT * 1000);
305}
306
307static int intel_spi_init(struct intel_spi *ispi)
308{
309	u32 opmenu0, opmenu1, lvscc, uvscc, val;
310	int i;
311
312	switch (ispi->info->type) {
313	case INTEL_SPI_BYT:
314		ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
315		ispi->pregs = ispi->base + BYT_PR;
316		ispi->nregions = BYT_FREG_NUM;
317		ispi->pr_num = BYT_PR_NUM;
318		ispi->swseq_reg = true;
319
320		if (writeable) {
321			/* Disable write protection */
322			val = readl(ispi->base + BYT_BCR);
323			if (!(val & BYT_BCR_WPD)) {
324				val |= BYT_BCR_WPD;
325				writel(val, ispi->base + BYT_BCR);
326				val = readl(ispi->base + BYT_BCR);
327			}
328
329			ispi->writeable = !!(val & BYT_BCR_WPD);
330		}
331
332		break;
333
334	case INTEL_SPI_LPT:
335		ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
336		ispi->pregs = ispi->base + LPT_PR;
337		ispi->nregions = LPT_FREG_NUM;
338		ispi->pr_num = LPT_PR_NUM;
339		ispi->swseq_reg = true;
340		break;
341
342	case INTEL_SPI_BXT:
343		ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
344		ispi->pregs = ispi->base + BXT_PR;
345		ispi->nregions = BXT_FREG_NUM;
346		ispi->pr_num = BXT_PR_NUM;
347		ispi->erase_64k = true;
348		break;
349
350	case INTEL_SPI_CNL:
351		ispi->sregs = NULL;
352		ispi->pregs = ispi->base + CNL_PR;
353		ispi->nregions = CNL_FREG_NUM;
354		ispi->pr_num = CNL_PR_NUM;
355		break;
356
357	default:
358		return -EINVAL;
359	}
360
361	/* Disable #SMI generation from HW sequencer */
362	val = readl(ispi->base + HSFSTS_CTL);
363	val &= ~HSFSTS_CTL_FSMIE;
364	writel(val, ispi->base + HSFSTS_CTL);
365
366	/*
367	 * Determine whether erase operation should use HW or SW sequencer.
368	 *
369	 * The HW sequencer has a predefined list of opcodes, with only the
370	 * erase opcode being programmable in LVSCC and UVSCC registers.
371	 * If these registers don't contain a valid erase opcode, erase
372	 * cannot be done using HW sequencer.
373	 */
374	lvscc = readl(ispi->base + LVSCC);
375	uvscc = readl(ispi->base + UVSCC);
376	if (!(lvscc & ERASE_OPCODE_MASK) || !(uvscc & ERASE_OPCODE_MASK))
377		ispi->swseq_erase = true;
378	/* SPI controller on Intel BXT supports 64K erase opcode */
379	if (ispi->info->type == INTEL_SPI_BXT && !ispi->swseq_erase)
380		if (!(lvscc & ERASE_64K_OPCODE_MASK) ||
381		    !(uvscc & ERASE_64K_OPCODE_MASK))
382			ispi->erase_64k = false;
383
384	if (ispi->sregs == NULL && (ispi->swseq_reg || ispi->swseq_erase)) {
385		dev_err(ispi->dev, "software sequencer not supported, but required\n");
386		return -EINVAL;
387	}
388
389	/*
390	 * Some controllers can only do basic operations using hardware
391	 * sequencer. All other operations are supposed to be carried out
392	 * using software sequencer.
393	 */
394	if (ispi->swseq_reg) {
395		/* Disable #SMI generation from SW sequencer */
396		val = readl(ispi->sregs + SSFSTS_CTL);
397		val &= ~SSFSTS_CTL_FSMIE;
398		writel(val, ispi->sregs + SSFSTS_CTL);
399	}
400
401	/* Check controller's lock status */
402	val = readl(ispi->base + HSFSTS_CTL);
403	ispi->locked = !!(val & HSFSTS_CTL_FLOCKDN);
404
405	if (ispi->locked && ispi->sregs) {
406		/*
407		 * BIOS programs allowed opcodes and then locks down the
408		 * register. So read back what opcodes it decided to support.
409		 * That's the set we are going to support as well.
410		 */
411		opmenu0 = readl(ispi->sregs + OPMENU0);
412		opmenu1 = readl(ispi->sregs + OPMENU1);
413
414		if (opmenu0 && opmenu1) {
415			for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
416				ispi->opcodes[i] = opmenu0 >> i * 8;
417				ispi->opcodes[i + 4] = opmenu1 >> i * 8;
418			}
419		}
420	}
421
422	intel_spi_dump_regs(ispi);
423
424	return 0;
425}
426
427static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode, int optype)
428{
429	int i;
430	int preop;
431
432	if (ispi->locked) {
433		for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
434			if (ispi->opcodes[i] == opcode)
435				return i;
436
437		return -EINVAL;
438	}
439
440	/* The lock is off, so just use index 0 */
441	writel(opcode, ispi->sregs + OPMENU0);
442	preop = readw(ispi->sregs + PREOP_OPTYPE);
443	writel(optype << 16 | preop, ispi->sregs + PREOP_OPTYPE);
444
445	return 0;
446}
447
448static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, size_t len)
449{
450	u32 val, status;
451	int ret;
452
453	val = readl(ispi->base + HSFSTS_CTL);
454	val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
455
456	switch (opcode) {
457	case SPINOR_OP_RDID:
458		val |= HSFSTS_CTL_FCYCLE_RDID;
459		break;
460	case SPINOR_OP_WRSR:
461		val |= HSFSTS_CTL_FCYCLE_WRSR;
462		break;
463	case SPINOR_OP_RDSR:
464		val |= HSFSTS_CTL_FCYCLE_RDSR;
465		break;
466	default:
467		return -EINVAL;
468	}
469
470	if (len > INTEL_SPI_FIFO_SZ)
471		return -EINVAL;
472
473	val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
474	val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
475	val |= HSFSTS_CTL_FGO;
476	writel(val, ispi->base + HSFSTS_CTL);
477
478	ret = intel_spi_wait_hw_busy(ispi);
479	if (ret)
480		return ret;
481
482	status = readl(ispi->base + HSFSTS_CTL);
483	if (status & HSFSTS_CTL_FCERR)
484		return -EIO;
485	else if (status & HSFSTS_CTL_AEL)
486		return -EACCES;
487
488	return 0;
489}
490
491static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, size_t len,
492			      int optype)
493{
494	u32 val = 0, status;
495	u8 atomic_preopcode;
496	int ret;
497
498	ret = intel_spi_opcode_index(ispi, opcode, optype);
499	if (ret < 0)
500		return ret;
501
502	if (len > INTEL_SPI_FIFO_SZ)
503		return -EINVAL;
504
505	/*
506	 * Always clear it after each SW sequencer operation regardless
507	 * of whether it is successful or not.
508	 */
509	atomic_preopcode = ispi->atomic_preopcode;
510	ispi->atomic_preopcode = 0;
511
512	/* Only mark 'Data Cycle' bit when there is data to be transferred */
513	if (len > 0)
514		val = ((len - 1) << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
515	val |= ret << SSFSTS_CTL_COP_SHIFT;
516	val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
517	val |= SSFSTS_CTL_SCGO;
518	if (atomic_preopcode) {
519		u16 preop;
520
521		switch (optype) {
522		case OPTYPE_WRITE_NO_ADDR:
523		case OPTYPE_WRITE_WITH_ADDR:
524			/* Pick matching preopcode for the atomic sequence */
525			preop = readw(ispi->sregs + PREOP_OPTYPE);
526			if ((preop & 0xff) == atomic_preopcode)
527				; /* Do nothing */
528			else if ((preop >> 8) == atomic_preopcode)
529				val |= SSFSTS_CTL_SPOP;
530			else
531				return -EINVAL;
532
533			/* Enable atomic sequence */
534			val |= SSFSTS_CTL_ACS;
535			break;
536
537		default:
538			return -EINVAL;
539		}
540
541	}
542	writel(val, ispi->sregs + SSFSTS_CTL);
543
544	ret = intel_spi_wait_sw_busy(ispi);
545	if (ret)
546		return ret;
547
548	status = readl(ispi->sregs + SSFSTS_CTL);
549	if (status & SSFSTS_CTL_FCERR)
550		return -EIO;
551	else if (status & SSFSTS_CTL_AEL)
552		return -EACCES;
553
554	return 0;
555}
556
557static int intel_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
558			      size_t len)
559{
560	struct intel_spi *ispi = nor->priv;
561	int ret;
562
563	/* Address of the first chip */
564	writel(0, ispi->base + FADDR);
565
566	if (ispi->swseq_reg)
567		ret = intel_spi_sw_cycle(ispi, opcode, len,
568					 OPTYPE_READ_NO_ADDR);
569	else
570		ret = intel_spi_hw_cycle(ispi, opcode, len);
571
572	if (ret)
573		return ret;
574
575	return intel_spi_read_block(ispi, buf, len);
576}
577
578static int intel_spi_write_reg(struct spi_nor *nor, u8 opcode, const u8 *buf,
579			       size_t len)
580{
581	struct intel_spi *ispi = nor->priv;
582	int ret;
583
584	/*
585	 * This is handled with atomic operation and preop code in Intel
586	 * controller so we only verify that it is available. If the
587	 * controller is not locked, program the opcode to the PREOP
588	 * register for later use.
589	 *
590	 * When hardware sequencer is used there is no need to program
591	 * any opcodes (it handles them automatically as part of a command).
592	 */
593	if (opcode == SPINOR_OP_WREN) {
594		u16 preop;
595
596		if (!ispi->swseq_reg)
597			return 0;
598
599		preop = readw(ispi->sregs + PREOP_OPTYPE);
600		if ((preop & 0xff) != opcode && (preop >> 8) != opcode) {
601			if (ispi->locked)
602				return -EINVAL;
603			writel(opcode, ispi->sregs + PREOP_OPTYPE);
604		}
605
606		/*
607		 * This enables atomic sequence on next SW sycle. Will
608		 * be cleared after next operation.
609		 */
610		ispi->atomic_preopcode = opcode;
611		return 0;
612	}
613
614	/*
615	 * We hope that HW sequencer will do the right thing automatically and
616	 * with the SW sequencer we cannot use preopcode anyway, so just ignore
617	 * the Write Disable operation and pretend it was completed
618	 * successfully.
619	 */
620	if (opcode == SPINOR_OP_WRDI)
621		return 0;
622
623	writel(0, ispi->base + FADDR);
624
625	/* Write the value beforehand */
626	ret = intel_spi_write_block(ispi, buf, len);
627	if (ret)
628		return ret;
629
630	if (ispi->swseq_reg)
631		return intel_spi_sw_cycle(ispi, opcode, len,
632					  OPTYPE_WRITE_NO_ADDR);
633	return intel_spi_hw_cycle(ispi, opcode, len);
634}
635
636static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len,
637			      u_char *read_buf)
638{
639	struct intel_spi *ispi = nor->priv;
640	size_t block_size, retlen = 0;
641	u32 val, status;
642	ssize_t ret;
643
644	/*
645	 * Atomic sequence is not expected with HW sequencer reads. Make
646	 * sure it is cleared regardless.
647	 */
648	if (WARN_ON_ONCE(ispi->atomic_preopcode))
649		ispi->atomic_preopcode = 0;
650
651	switch (nor->read_opcode) {
652	case SPINOR_OP_READ:
653	case SPINOR_OP_READ_FAST:
654	case SPINOR_OP_READ_4B:
655	case SPINOR_OP_READ_FAST_4B:
656		break;
657	default:
658		return -EINVAL;
659	}
660
661	while (len > 0) {
662		block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
663
664		/* Read cannot cross 4K boundary */
665		block_size = min_t(loff_t, from + block_size,
666				   round_up(from + 1, SZ_4K)) - from;
667
668		writel(from, ispi->base + FADDR);
669
670		val = readl(ispi->base + HSFSTS_CTL);
671		val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
672		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
673		val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
674		val |= HSFSTS_CTL_FCYCLE_READ;
675		val |= HSFSTS_CTL_FGO;
676		writel(val, ispi->base + HSFSTS_CTL);
677
678		ret = intel_spi_wait_hw_busy(ispi);
679		if (ret)
680			return ret;
681
682		status = readl(ispi->base + HSFSTS_CTL);
683		if (status & HSFSTS_CTL_FCERR)
684			ret = -EIO;
685		else if (status & HSFSTS_CTL_AEL)
686			ret = -EACCES;
687
688		if (ret < 0) {
689			dev_err(ispi->dev, "read error: %llx: %#x\n", from,
690				status);
691			return ret;
692		}
693
694		ret = intel_spi_read_block(ispi, read_buf, block_size);
695		if (ret)
696			return ret;
697
698		len -= block_size;
699		from += block_size;
700		retlen += block_size;
701		read_buf += block_size;
702	}
703
704	return retlen;
705}
706
707static ssize_t intel_spi_write(struct spi_nor *nor, loff_t to, size_t len,
708			       const u_char *write_buf)
709{
710	struct intel_spi *ispi = nor->priv;
711	size_t block_size, retlen = 0;
712	u32 val, status;
713	ssize_t ret;
714
715	/* Not needed with HW sequencer write, make sure it is cleared */
716	ispi->atomic_preopcode = 0;
717
718	while (len > 0) {
719		block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
720
721		/* Write cannot cross 4K boundary */
722		block_size = min_t(loff_t, to + block_size,
723				   round_up(to + 1, SZ_4K)) - to;
724
725		writel(to, ispi->base + FADDR);
726
727		val = readl(ispi->base + HSFSTS_CTL);
728		val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
729		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
730		val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
731		val |= HSFSTS_CTL_FCYCLE_WRITE;
732
733		ret = intel_spi_write_block(ispi, write_buf, block_size);
734		if (ret) {
735			dev_err(ispi->dev, "failed to write block\n");
736			return ret;
737		}
738
739		/* Start the write now */
740		val |= HSFSTS_CTL_FGO;
741		writel(val, ispi->base + HSFSTS_CTL);
742
743		ret = intel_spi_wait_hw_busy(ispi);
744		if (ret) {
745			dev_err(ispi->dev, "timeout\n");
746			return ret;
747		}
748
749		status = readl(ispi->base + HSFSTS_CTL);
750		if (status & HSFSTS_CTL_FCERR)
751			ret = -EIO;
752		else if (status & HSFSTS_CTL_AEL)
753			ret = -EACCES;
754
755		if (ret < 0) {
756			dev_err(ispi->dev, "write error: %llx: %#x\n", to,
757				status);
758			return ret;
759		}
760
761		len -= block_size;
762		to += block_size;
763		retlen += block_size;
764		write_buf += block_size;
765	}
766
767	return retlen;
768}
769
770static int intel_spi_erase(struct spi_nor *nor, loff_t offs)
771{
772	size_t erase_size, len = nor->mtd.erasesize;
773	struct intel_spi *ispi = nor->priv;
774	u32 val, status, cmd;
775	int ret;
776
777	/* If the hardware can do 64k erase use that when possible */
778	if (len >= SZ_64K && ispi->erase_64k) {
779		cmd = HSFSTS_CTL_FCYCLE_ERASE_64K;
780		erase_size = SZ_64K;
781	} else {
782		cmd = HSFSTS_CTL_FCYCLE_ERASE;
783		erase_size = SZ_4K;
784	}
785
786	if (ispi->swseq_erase) {
787		while (len > 0) {
788			writel(offs, ispi->base + FADDR);
789
790			ret = intel_spi_sw_cycle(ispi, nor->erase_opcode,
791						 0, OPTYPE_WRITE_WITH_ADDR);
792			if (ret)
793				return ret;
794
795			offs += erase_size;
796			len -= erase_size;
797		}
798
799		return 0;
800	}
801
802	/* Not needed with HW sequencer erase, make sure it is cleared */
803	ispi->atomic_preopcode = 0;
804
805	while (len > 0) {
806		writel(offs, ispi->base + FADDR);
807
808		val = readl(ispi->base + HSFSTS_CTL);
809		val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
810		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
811		val |= cmd;
812		val |= HSFSTS_CTL_FGO;
813		writel(val, ispi->base + HSFSTS_CTL);
814
815		ret = intel_spi_wait_hw_busy(ispi);
816		if (ret)
817			return ret;
818
819		status = readl(ispi->base + HSFSTS_CTL);
820		if (status & HSFSTS_CTL_FCERR)
821			return -EIO;
822		else if (status & HSFSTS_CTL_AEL)
823			return -EACCES;
824
825		offs += erase_size;
826		len -= erase_size;
827	}
828
829	return 0;
830}
831
832static bool intel_spi_is_protected(const struct intel_spi *ispi,
833				   unsigned int base, unsigned int limit)
834{
835	int i;
836
837	for (i = 0; i < ispi->pr_num; i++) {
838		u32 pr_base, pr_limit, pr_value;
839
840		pr_value = readl(ispi->pregs + PR(i));
841		if (!(pr_value & (PR_WPE | PR_RPE)))
842			continue;
843
844		pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
845		pr_base = pr_value & PR_BASE_MASK;
846
847		if (pr_base >= base && pr_limit <= limit)
848			return true;
849	}
850
851	return false;
852}
853
854/*
855 * There will be a single partition holding all enabled flash regions. We
856 * call this "BIOS".
857 */
858static void intel_spi_fill_partition(struct intel_spi *ispi,
859				     struct mtd_partition *part)
860{
861	u64 end;
862	int i;
863
864	memset(part, 0, sizeof(*part));
865
866	/* Start from the mandatory descriptor region */
867	part->size = 4096;
868	part->name = "BIOS";
869
870	/*
871	 * Now try to find where this partition ends based on the flash
872	 * region registers.
873	 */
874	for (i = 1; i < ispi->nregions; i++) {
875		u32 region, base, limit;
876
877		region = readl(ispi->base + FREG(i));
878		base = region & FREG_BASE_MASK;
879		limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
880
881		if (base >= limit || limit == 0)
882			continue;
883
884		/*
885		 * If any of the regions have protection bits set, make the
886		 * whole partition read-only to be on the safe side.
887		 */
888		if (intel_spi_is_protected(ispi, base, limit))
889			ispi->writeable = false;
890
891		end = (limit << 12) + 4096;
892		if (end > part->size)
893			part->size = end;
894	}
895}
896
897static const struct spi_nor_controller_ops intel_spi_controller_ops = {
898	.read_reg = intel_spi_read_reg,
899	.write_reg = intel_spi_write_reg,
900	.read = intel_spi_read,
901	.write = intel_spi_write,
902	.erase = intel_spi_erase,
903};
904
905struct intel_spi *intel_spi_probe(struct device *dev,
906	struct resource *mem, const struct intel_spi_boardinfo *info)
907{
908	const struct spi_nor_hwcaps hwcaps = {
909		.mask = SNOR_HWCAPS_READ |
910			SNOR_HWCAPS_READ_FAST |
911			SNOR_HWCAPS_PP,
912	};
913	struct mtd_partition part;
914	struct intel_spi *ispi;
915	int ret;
916
917	if (!info || !mem)
918		return ERR_PTR(-EINVAL);
919
920	ispi = devm_kzalloc(dev, sizeof(*ispi), GFP_KERNEL);
921	if (!ispi)
922		return ERR_PTR(-ENOMEM);
923
924	ispi->base = devm_ioremap_resource(dev, mem);
925	if (IS_ERR(ispi->base))
926		return ERR_CAST(ispi->base);
927
928	ispi->dev = dev;
929	ispi->info = info;
930	ispi->writeable = info->writeable;
931
932	ret = intel_spi_init(ispi);
933	if (ret)
934		return ERR_PTR(ret);
935
936	ispi->nor.dev = ispi->dev;
937	ispi->nor.priv = ispi;
938	ispi->nor.controller_ops = &intel_spi_controller_ops;
939
940	ret = spi_nor_scan(&ispi->nor, NULL, &hwcaps);
941	if (ret) {
942		dev_info(dev, "failed to locate the chip\n");
943		return ERR_PTR(ret);
944	}
945
946	intel_spi_fill_partition(ispi, &part);
947
948	/* Prevent writes if not explicitly enabled */
949	if (!ispi->writeable || !writeable)
950		ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
951
952	ret = mtd_device_register(&ispi->nor.mtd, &part, 1);
953	if (ret)
954		return ERR_PTR(ret);
955
956	return ispi;
957}
958EXPORT_SYMBOL_GPL(intel_spi_probe);
959
960int intel_spi_remove(struct intel_spi *ispi)
961{
962	return mtd_device_unregister(&ispi->nor.mtd);
963}
964EXPORT_SYMBOL_GPL(intel_spi_remove);
965
966MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
967MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
968MODULE_LICENSE("GPL v2");