xref: /openbmc/linux/drivers/mtd/devices/st_spi_fsm.c (revision ecefa105)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * st_spi_fsm.c	- ST Fast Sequence Mode (FSM) Serial Flash Controller
4  *
5  * Author: Angus Clark <angus.clark@st.com>
6  *
7  * Copyright (C) 2010-2014 STMicroelectronics Limited
8  *
9  * JEDEC probe based on drivers/mtd/devices/m25p80.c
10  */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/regmap.h>
14 #include <linux/platform_device.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/partitions.h>
18 #include <linux/mtd/spi-nor.h>
19 #include <linux/sched.h>
20 #include <linux/delay.h>
21 #include <linux/io.h>
22 #include <linux/of.h>
23 #include <linux/clk.h>
24 
25 #include "serial_flash_cmds.h"
26 
27 /*
28  * FSM SPI Controller Registers
29  */
30 #define SPI_CLOCKDIV			0x0010
31 #define SPI_MODESELECT			0x0018
32 #define SPI_CONFIGDATA			0x0020
33 #define SPI_STA_MODE_CHANGE		0x0028
34 #define SPI_FAST_SEQ_TRANSFER_SIZE	0x0100
35 #define SPI_FAST_SEQ_ADD1		0x0104
36 #define SPI_FAST_SEQ_ADD2		0x0108
37 #define SPI_FAST_SEQ_ADD_CFG		0x010c
38 #define SPI_FAST_SEQ_OPC1		0x0110
39 #define SPI_FAST_SEQ_OPC2		0x0114
40 #define SPI_FAST_SEQ_OPC3		0x0118
41 #define SPI_FAST_SEQ_OPC4		0x011c
42 #define SPI_FAST_SEQ_OPC5		0x0120
43 #define SPI_MODE_BITS			0x0124
44 #define SPI_DUMMY_BITS			0x0128
45 #define SPI_FAST_SEQ_FLASH_STA_DATA	0x012c
46 #define SPI_FAST_SEQ_1			0x0130
47 #define SPI_FAST_SEQ_2			0x0134
48 #define SPI_FAST_SEQ_3			0x0138
49 #define SPI_FAST_SEQ_4			0x013c
50 #define SPI_FAST_SEQ_CFG		0x0140
51 #define SPI_FAST_SEQ_STA		0x0144
52 #define SPI_QUAD_BOOT_SEQ_INIT_1	0x0148
53 #define SPI_QUAD_BOOT_SEQ_INIT_2	0x014c
54 #define SPI_QUAD_BOOT_READ_SEQ_1	0x0150
55 #define SPI_QUAD_BOOT_READ_SEQ_2	0x0154
56 #define SPI_PROGRAM_ERASE_TIME		0x0158
57 #define SPI_MULT_PAGE_REPEAT_SEQ_1	0x015c
58 #define SPI_MULT_PAGE_REPEAT_SEQ_2	0x0160
59 #define SPI_STATUS_WR_TIME_REG		0x0164
60 #define SPI_FAST_SEQ_DATA_REG		0x0300
61 
62 /*
63  * Register: SPI_MODESELECT
64  */
65 #define SPI_MODESELECT_CONTIG		0x01
66 #define SPI_MODESELECT_FASTREAD		0x02
67 #define SPI_MODESELECT_DUALIO		0x04
68 #define SPI_MODESELECT_FSM		0x08
69 #define SPI_MODESELECT_QUADBOOT		0x10
70 
71 /*
72  * Register: SPI_CONFIGDATA
73  */
74 #define SPI_CFG_DEVICE_ST		0x1
75 #define SPI_CFG_DEVICE_ATMEL		0x4
76 #define SPI_CFG_MIN_CS_HIGH(x)		(((x) & 0xfff) << 4)
77 #define SPI_CFG_CS_SETUPHOLD(x)		(((x) & 0xff) << 16)
78 #define SPI_CFG_DATA_HOLD(x)		(((x) & 0xff) << 24)
79 
80 #define SPI_CFG_DEFAULT_MIN_CS_HIGH    SPI_CFG_MIN_CS_HIGH(0x0AA)
81 #define SPI_CFG_DEFAULT_CS_SETUPHOLD   SPI_CFG_CS_SETUPHOLD(0xA0)
82 #define SPI_CFG_DEFAULT_DATA_HOLD      SPI_CFG_DATA_HOLD(0x00)
83 
84 /*
85  * Register: SPI_FAST_SEQ_TRANSFER_SIZE
86  */
87 #define TRANSFER_SIZE(x)		((x) * 8)
88 
89 /*
90  * Register: SPI_FAST_SEQ_ADD_CFG
91  */
92 #define ADR_CFG_CYCLES_ADD1(x)		((x) << 0)
93 #define ADR_CFG_PADS_1_ADD1		(0x0 << 6)
94 #define ADR_CFG_PADS_2_ADD1		(0x1 << 6)
95 #define ADR_CFG_PADS_4_ADD1		(0x3 << 6)
96 #define ADR_CFG_CSDEASSERT_ADD1		(1   << 8)
97 #define ADR_CFG_CYCLES_ADD2(x)		((x) << (0+16))
98 #define ADR_CFG_PADS_1_ADD2		(0x0 << (6+16))
99 #define ADR_CFG_PADS_2_ADD2		(0x1 << (6+16))
100 #define ADR_CFG_PADS_4_ADD2		(0x3 << (6+16))
101 #define ADR_CFG_CSDEASSERT_ADD2		(1   << (8+16))
102 
103 /*
104  * Register: SPI_FAST_SEQ_n
105  */
106 #define SEQ_OPC_OPCODE(x)		((x) << 0)
107 #define SEQ_OPC_CYCLES(x)		((x) << 8)
108 #define SEQ_OPC_PADS_1			(0x0 << 14)
109 #define SEQ_OPC_PADS_2			(0x1 << 14)
110 #define SEQ_OPC_PADS_4			(0x3 << 14)
111 #define SEQ_OPC_CSDEASSERT		(1   << 16)
112 
113 /*
114  * Register: SPI_FAST_SEQ_CFG
115  */
116 #define SEQ_CFG_STARTSEQ		(1 << 0)
117 #define SEQ_CFG_SWRESET			(1 << 5)
118 #define SEQ_CFG_CSDEASSERT		(1 << 6)
119 #define SEQ_CFG_READNOTWRITE		(1 << 7)
120 #define SEQ_CFG_ERASE			(1 << 8)
121 #define SEQ_CFG_PADS_1			(0x0 << 16)
122 #define SEQ_CFG_PADS_2			(0x1 << 16)
123 #define SEQ_CFG_PADS_4			(0x3 << 16)
124 
125 /*
126  * Register: SPI_MODE_BITS
127  */
128 #define MODE_DATA(x)			(x & 0xff)
129 #define MODE_CYCLES(x)			((x & 0x3f) << 16)
130 #define MODE_PADS_1			(0x0 << 22)
131 #define MODE_PADS_2			(0x1 << 22)
132 #define MODE_PADS_4			(0x3 << 22)
133 #define DUMMY_CSDEASSERT		(1   << 24)
134 
135 /*
136  * Register: SPI_DUMMY_BITS
137  */
138 #define DUMMY_CYCLES(x)			((x & 0x3f) << 16)
139 #define DUMMY_PADS_1			(0x0 << 22)
140 #define DUMMY_PADS_2			(0x1 << 22)
141 #define DUMMY_PADS_4			(0x3 << 22)
142 #define DUMMY_CSDEASSERT		(1   << 24)
143 
144 /*
145  * Register: SPI_FAST_SEQ_FLASH_STA_DATA
146  */
147 #define STA_DATA_BYTE1(x)		((x & 0xff) << 0)
148 #define STA_DATA_BYTE2(x)		((x & 0xff) << 8)
149 #define STA_PADS_1			(0x0 << 16)
150 #define STA_PADS_2			(0x1 << 16)
151 #define STA_PADS_4			(0x3 << 16)
152 #define STA_CSDEASSERT			(0x1 << 20)
153 #define STA_RDNOTWR			(0x1 << 21)
154 
155 /*
156  * FSM SPI Instruction Opcodes
157  */
158 #define STFSM_OPC_CMD			0x1
159 #define STFSM_OPC_ADD			0x2
160 #define STFSM_OPC_STA			0x3
161 #define STFSM_OPC_MODE			0x4
162 #define STFSM_OPC_DUMMY		0x5
163 #define STFSM_OPC_DATA			0x6
164 #define STFSM_OPC_WAIT			0x7
165 #define STFSM_OPC_JUMP			0x8
166 #define STFSM_OPC_GOTO			0x9
167 #define STFSM_OPC_STOP			0xF
168 
169 /*
170  * FSM SPI Instructions (== opcode + operand).
171  */
172 #define STFSM_INSTR(cmd, op)		((cmd) | ((op) << 4))
173 
174 #define STFSM_INST_CMD1			STFSM_INSTR(STFSM_OPC_CMD,	1)
175 #define STFSM_INST_CMD2			STFSM_INSTR(STFSM_OPC_CMD,	2)
176 #define STFSM_INST_CMD3			STFSM_INSTR(STFSM_OPC_CMD,	3)
177 #define STFSM_INST_CMD4			STFSM_INSTR(STFSM_OPC_CMD,	4)
178 #define STFSM_INST_CMD5			STFSM_INSTR(STFSM_OPC_CMD,	5)
179 #define STFSM_INST_ADD1			STFSM_INSTR(STFSM_OPC_ADD,	1)
180 #define STFSM_INST_ADD2			STFSM_INSTR(STFSM_OPC_ADD,	2)
181 
182 #define STFSM_INST_DATA_WRITE		STFSM_INSTR(STFSM_OPC_DATA,	1)
183 #define STFSM_INST_DATA_READ		STFSM_INSTR(STFSM_OPC_DATA,	2)
184 
185 #define STFSM_INST_STA_RD1		STFSM_INSTR(STFSM_OPC_STA,	0x1)
186 #define STFSM_INST_STA_WR1		STFSM_INSTR(STFSM_OPC_STA,	0x1)
187 #define STFSM_INST_STA_RD2		STFSM_INSTR(STFSM_OPC_STA,	0x2)
188 #define STFSM_INST_STA_WR1_2		STFSM_INSTR(STFSM_OPC_STA,	0x3)
189 
190 #define STFSM_INST_MODE			STFSM_INSTR(STFSM_OPC_MODE,	0)
191 #define STFSM_INST_DUMMY		STFSM_INSTR(STFSM_OPC_DUMMY,	0)
192 #define STFSM_INST_WAIT			STFSM_INSTR(STFSM_OPC_WAIT,	0)
193 #define STFSM_INST_STOP			STFSM_INSTR(STFSM_OPC_STOP,	0)
194 
195 #define STFSM_DEFAULT_EMI_FREQ 100000000UL                        /* 100 MHz */
196 #define STFSM_DEFAULT_WR_TIME  (STFSM_DEFAULT_EMI_FREQ * (15/1000)) /* 15ms */
197 
198 #define STFSM_FLASH_SAFE_FREQ  10000000UL                         /* 10 MHz */
199 
200 #define STFSM_MAX_WAIT_SEQ_MS  1000     /* FSM execution time */
201 
202 /* S25FLxxxS commands */
203 #define S25FL_CMD_WRITE4_1_1_4 0x34
204 #define S25FL_CMD_SE4          0xdc
205 #define S25FL_CMD_CLSR         0x30
206 #define S25FL_CMD_DYBWR                0xe1
207 #define S25FL_CMD_DYBRD                0xe0
208 #define S25FL_CMD_WRITE4       0x12    /* Note, opcode clashes with
209 					* 'SPINOR_OP_WRITE_1_4_4'
210 					* as found on N25Qxxx devices! */
211 
212 /* Status register */
213 #define FLASH_STATUS_BUSY      0x01
214 #define FLASH_STATUS_WEL       0x02
215 #define FLASH_STATUS_BP0       0x04
216 #define FLASH_STATUS_BP1       0x08
217 #define FLASH_STATUS_BP2       0x10
218 #define FLASH_STATUS_SRWP0     0x80
219 #define FLASH_STATUS_TIMEOUT   0xff
220 /* S25FL Error Flags */
221 #define S25FL_STATUS_E_ERR     0x20
222 #define S25FL_STATUS_P_ERR     0x40
223 
224 #define N25Q_CMD_WRVCR         0x81
225 #define N25Q_CMD_RDVCR         0x85
226 #define N25Q_CMD_RDVECR        0x65
227 #define N25Q_CMD_RDNVCR        0xb5
228 #define N25Q_CMD_WRNVCR        0xb1
229 
230 #define FLASH_PAGESIZE         256			/* In Bytes    */
231 #define FLASH_PAGESIZE_32      (FLASH_PAGESIZE / 4)	/* In uint32_t */
232 #define FLASH_MAX_BUSY_WAIT    (300 * HZ)	/* Maximum 'CHIPERASE' time */
233 
234 /*
235  * Flags to tweak operation of default read/write/erase routines
236  */
237 #define CFG_READ_TOGGLE_32BIT_ADDR     0x00000001
238 #define CFG_WRITE_TOGGLE_32BIT_ADDR    0x00000002
239 #define CFG_ERASESEC_TOGGLE_32BIT_ADDR 0x00000008
240 #define CFG_S25FL_CHECK_ERROR_FLAGS    0x00000010
241 
242 struct stfsm_seq {
243 	uint32_t data_size;
244 	uint32_t addr1;
245 	uint32_t addr2;
246 	uint32_t addr_cfg;
247 	uint32_t seq_opc[5];
248 	uint32_t mode;
249 	uint32_t dummy;
250 	uint32_t status;
251 	uint8_t  seq[16];
252 	uint32_t seq_cfg;
253 } __packed __aligned(4);
254 
255 struct stfsm {
256 	struct device		*dev;
257 	void __iomem		*base;
258 	struct mtd_info		mtd;
259 	struct mutex		lock;
260 	struct flash_info       *info;
261 	struct clk              *clk;
262 
263 	uint32_t                configuration;
264 	uint32_t                fifo_dir_delay;
265 	bool                    booted_from_spi;
266 	bool                    reset_signal;
267 	bool                    reset_por;
268 
269 	struct stfsm_seq stfsm_seq_read;
270 	struct stfsm_seq stfsm_seq_write;
271 	struct stfsm_seq stfsm_seq_en_32bit_addr;
272 };
273 
274 /* Parameters to configure a READ or WRITE FSM sequence */
275 struct seq_rw_config {
276 	uint32_t        flags;          /* flags to support config */
277 	uint8_t         cmd;            /* FLASH command */
278 	int             write;          /* Write Sequence */
279 	uint8_t         addr_pads;      /* No. of addr pads (MODE & DUMMY) */
280 	uint8_t         data_pads;      /* No. of data pads */
281 	uint8_t         mode_data;      /* MODE data */
282 	uint8_t         mode_cycles;    /* No. of MODE cycles */
283 	uint8_t         dummy_cycles;   /* No. of DUMMY cycles */
284 };
285 
286 /* SPI Flash Device Table */
287 struct flash_info {
288 	char            *name;
289 	/*
290 	 * JEDEC id zero means "no ID" (most older chips); otherwise it has
291 	 * a high byte of zero plus three data bytes: the manufacturer id,
292 	 * then a two byte device id.
293 	 */
294 	u32             jedec_id;
295 	u16             ext_id;
296 	/*
297 	 * The size listed here is what works with SPINOR_OP_SE, which isn't
298 	 * necessarily called a "sector" by the vendor.
299 	 */
300 	unsigned        sector_size;
301 	u16             n_sectors;
302 	u32             flags;
303 	/*
304 	 * Note, where FAST_READ is supported, freq_max specifies the
305 	 * FAST_READ frequency, not the READ frequency.
306 	 */
307 	u32             max_freq;
308 	int             (*config)(struct stfsm *);
309 };
310 
311 static int stfsm_n25q_config(struct stfsm *fsm);
312 static int stfsm_mx25_config(struct stfsm *fsm);
313 static int stfsm_s25fl_config(struct stfsm *fsm);
314 static int stfsm_w25q_config(struct stfsm *fsm);
315 
316 static struct flash_info flash_types[] = {
317 	/*
318 	 * ST Microelectronics/Numonyx --
319 	 * (newer production versions may have feature updates
320 	 * (eg faster operating frequency)
321 	 */
322 #define M25P_FLAG (FLASH_FLAG_READ_WRITE | FLASH_FLAG_READ_FAST)
323 	{ "m25p40",  0x202013, 0,  64 * 1024,   8, M25P_FLAG, 25, NULL },
324 	{ "m25p80",  0x202014, 0,  64 * 1024,  16, M25P_FLAG, 25, NULL },
325 	{ "m25p16",  0x202015, 0,  64 * 1024,  32, M25P_FLAG, 25, NULL },
326 	{ "m25p32",  0x202016, 0,  64 * 1024,  64, M25P_FLAG, 50, NULL },
327 	{ "m25p64",  0x202017, 0,  64 * 1024, 128, M25P_FLAG, 50, NULL },
328 	{ "m25p128", 0x202018, 0, 256 * 1024,  64, M25P_FLAG, 50, NULL },
329 
330 #define M25PX_FLAG (FLASH_FLAG_READ_WRITE      |	\
331 		    FLASH_FLAG_READ_FAST        |	\
332 		    FLASH_FLAG_READ_1_1_2       |	\
333 		    FLASH_FLAG_WRITE_1_1_2)
334 	{ "m25px32", 0x207116, 0,  64 * 1024,  64, M25PX_FLAG, 75, NULL },
335 	{ "m25px64", 0x207117, 0,  64 * 1024, 128, M25PX_FLAG, 75, NULL },
336 
337 	/* Macronix MX25xxx
338 	 *     - Support for 'FLASH_FLAG_WRITE_1_4_4' is omitted for devices
339 	 *       where operating frequency must be reduced.
340 	 */
341 #define MX25_FLAG (FLASH_FLAG_READ_WRITE       |	\
342 		   FLASH_FLAG_READ_FAST         |	\
343 		   FLASH_FLAG_READ_1_1_2        |	\
344 		   FLASH_FLAG_READ_1_2_2        |	\
345 		   FLASH_FLAG_READ_1_1_4        |	\
346 		   FLASH_FLAG_SE_4K             |	\
347 		   FLASH_FLAG_SE_32K)
348 	{ "mx25l3255e",  0xc29e16, 0, 64 * 1024, 64,
349 	  (MX25_FLAG | FLASH_FLAG_WRITE_1_4_4), 86,
350 	  stfsm_mx25_config},
351 	{ "mx25l25635e", 0xc22019, 0, 64*1024, 512,
352 	  (MX25_FLAG | FLASH_FLAG_32BIT_ADDR | FLASH_FLAG_RESET), 70,
353 	  stfsm_mx25_config },
354 	{ "mx25l25655e", 0xc22619, 0, 64*1024, 512,
355 	  (MX25_FLAG | FLASH_FLAG_32BIT_ADDR | FLASH_FLAG_RESET), 70,
356 	  stfsm_mx25_config},
357 
358 #define N25Q_FLAG (FLASH_FLAG_READ_WRITE       |	\
359 		   FLASH_FLAG_READ_FAST         |	\
360 		   FLASH_FLAG_READ_1_1_2        |	\
361 		   FLASH_FLAG_READ_1_2_2        |	\
362 		   FLASH_FLAG_READ_1_1_4        |	\
363 		   FLASH_FLAG_READ_1_4_4        |	\
364 		   FLASH_FLAG_WRITE_1_1_2       |	\
365 		   FLASH_FLAG_WRITE_1_2_2       |	\
366 		   FLASH_FLAG_WRITE_1_1_4       |	\
367 		   FLASH_FLAG_WRITE_1_4_4)
368 	{ "n25q128", 0x20ba18, 0, 64 * 1024,  256, N25Q_FLAG, 108,
369 	  stfsm_n25q_config },
370 	{ "n25q256", 0x20ba19, 0, 64 * 1024,  512,
371 	  N25Q_FLAG | FLASH_FLAG_32BIT_ADDR, 108, stfsm_n25q_config },
372 
373 	/*
374 	 * Spansion S25FLxxxP
375 	 *     - 256KiB and 64KiB sector variants (identified by ext. JEDEC)
376 	 */
377 #define S25FLXXXP_FLAG (FLASH_FLAG_READ_WRITE  |	\
378 			FLASH_FLAG_READ_1_1_2   |	\
379 			FLASH_FLAG_READ_1_2_2   |	\
380 			FLASH_FLAG_READ_1_1_4   |	\
381 			FLASH_FLAG_READ_1_4_4   |	\
382 			FLASH_FLAG_WRITE_1_1_4  |	\
383 			FLASH_FLAG_READ_FAST)
384 	{ "s25fl032p",  0x010215, 0x4d00,  64 * 1024,  64, S25FLXXXP_FLAG, 80,
385 	  stfsm_s25fl_config},
386 	{ "s25fl129p0", 0x012018, 0x4d00, 256 * 1024,  64, S25FLXXXP_FLAG, 80,
387 	  stfsm_s25fl_config },
388 	{ "s25fl129p1", 0x012018, 0x4d01,  64 * 1024, 256, S25FLXXXP_FLAG, 80,
389 	  stfsm_s25fl_config },
390 
391 	/*
392 	 * Spansion S25FLxxxS
393 	 *     - 256KiB and 64KiB sector variants (identified by ext. JEDEC)
394 	 *     - RESET# signal supported by die but not bristled out on all
395 	 *       package types.  The package type is a function of board design,
396 	 *       so this information is captured in the board's flags.
397 	 *     - Supports 'DYB' sector protection. Depending on variant, sectors
398 	 *       may default to locked state on power-on.
399 	 */
400 #define S25FLXXXS_FLAG (S25FLXXXP_FLAG         |	\
401 			FLASH_FLAG_RESET        |	\
402 			FLASH_FLAG_DYB_LOCKING)
403 	{ "s25fl128s0", 0x012018, 0x0300,  256 * 1024, 64, S25FLXXXS_FLAG, 80,
404 	  stfsm_s25fl_config },
405 	{ "s25fl128s1", 0x012018, 0x0301,  64 * 1024, 256, S25FLXXXS_FLAG, 80,
406 	  stfsm_s25fl_config },
407 	{ "s25fl256s0", 0x010219, 0x4d00, 256 * 1024, 128,
408 	  S25FLXXXS_FLAG | FLASH_FLAG_32BIT_ADDR, 80, stfsm_s25fl_config },
409 	{ "s25fl256s1", 0x010219, 0x4d01,  64 * 1024, 512,
410 	  S25FLXXXS_FLAG | FLASH_FLAG_32BIT_ADDR, 80, stfsm_s25fl_config },
411 
412 	/* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
413 #define W25X_FLAG (FLASH_FLAG_READ_WRITE       |	\
414 		   FLASH_FLAG_READ_FAST         |	\
415 		   FLASH_FLAG_READ_1_1_2        |	\
416 		   FLASH_FLAG_WRITE_1_1_2)
417 	{ "w25x40",  0xef3013, 0,  64 * 1024,   8, W25X_FLAG, 75, NULL },
418 	{ "w25x80",  0xef3014, 0,  64 * 1024,  16, W25X_FLAG, 75, NULL },
419 	{ "w25x16",  0xef3015, 0,  64 * 1024,  32, W25X_FLAG, 75, NULL },
420 	{ "w25x32",  0xef3016, 0,  64 * 1024,  64, W25X_FLAG, 75, NULL },
421 	{ "w25x64",  0xef3017, 0,  64 * 1024, 128, W25X_FLAG, 75, NULL },
422 
423 	/* Winbond -- w25q "blocks" are 64K, "sectors" are 4KiB */
424 #define W25Q_FLAG (FLASH_FLAG_READ_WRITE       |	\
425 		   FLASH_FLAG_READ_FAST         |	\
426 		   FLASH_FLAG_READ_1_1_2        |	\
427 		   FLASH_FLAG_READ_1_2_2        |	\
428 		   FLASH_FLAG_READ_1_1_4        |	\
429 		   FLASH_FLAG_READ_1_4_4        |	\
430 		   FLASH_FLAG_WRITE_1_1_4)
431 	{ "w25q80",  0xef4014, 0,  64 * 1024,  16, W25Q_FLAG, 80,
432 	  stfsm_w25q_config },
433 	{ "w25q16",  0xef4015, 0,  64 * 1024,  32, W25Q_FLAG, 80,
434 	  stfsm_w25q_config },
435 	{ "w25q32",  0xef4016, 0,  64 * 1024,  64, W25Q_FLAG, 80,
436 	  stfsm_w25q_config },
437 	{ "w25q64",  0xef4017, 0,  64 * 1024, 128, W25Q_FLAG, 80,
438 	  stfsm_w25q_config },
439 
440 	/* Sentinel */
441 	{ NULL, 0x000000, 0, 0, 0, 0, 0, NULL },
442 };
443 
444 /*
445  * FSM message sequence configurations:
446  *
447  * All configs are presented in order of preference
448  */
449 
450 /* Default READ configurations, in order of preference */
451 static struct seq_rw_config default_read_configs[] = {
452 	{FLASH_FLAG_READ_1_4_4, SPINOR_OP_READ_1_4_4,	0, 4, 4, 0x00, 2, 4},
453 	{FLASH_FLAG_READ_1_1_4, SPINOR_OP_READ_1_1_4,	0, 1, 4, 0x00, 4, 0},
454 	{FLASH_FLAG_READ_1_2_2, SPINOR_OP_READ_1_2_2,	0, 2, 2, 0x00, 4, 0},
455 	{FLASH_FLAG_READ_1_1_2, SPINOR_OP_READ_1_1_2,	0, 1, 2, 0x00, 0, 8},
456 	{FLASH_FLAG_READ_FAST,	SPINOR_OP_READ_FAST,	0, 1, 1, 0x00, 0, 8},
457 	{FLASH_FLAG_READ_WRITE, SPINOR_OP_READ,		0, 1, 1, 0x00, 0, 0},
458 	{0x00,			0,			0, 0, 0, 0x00, 0, 0},
459 };
460 
461 /* Default WRITE configurations */
462 static struct seq_rw_config default_write_configs[] = {
463 	{FLASH_FLAG_WRITE_1_4_4, SPINOR_OP_WRITE_1_4_4, 1, 4, 4, 0x00, 0, 0},
464 	{FLASH_FLAG_WRITE_1_1_4, SPINOR_OP_WRITE_1_1_4, 1, 1, 4, 0x00, 0, 0},
465 	{FLASH_FLAG_WRITE_1_2_2, SPINOR_OP_WRITE_1_2_2, 1, 2, 2, 0x00, 0, 0},
466 	{FLASH_FLAG_WRITE_1_1_2, SPINOR_OP_WRITE_1_1_2, 1, 1, 2, 0x00, 0, 0},
467 	{FLASH_FLAG_READ_WRITE,  SPINOR_OP_WRITE,       1, 1, 1, 0x00, 0, 0},
468 	{0x00,			 0,			0, 0, 0, 0x00, 0, 0},
469 };
470 
471 /*
472  * [N25Qxxx] Configuration
473  */
474 #define N25Q_VCR_DUMMY_CYCLES(x)	(((x) & 0xf) << 4)
475 #define N25Q_VCR_XIP_DISABLED		((uint8_t)0x1 << 3)
476 #define N25Q_VCR_WRAP_CONT		0x3
477 
478 /* N25Q 3-byte Address READ configurations
479  *	- 'FAST' variants configured for 8 dummy cycles.
480  *
481  * Note, the number of dummy cycles used for 'FAST' READ operations is
482  * configurable and would normally be tuned according to the READ command and
483  * operating frequency.  However, this applies universally to all 'FAST' READ
484  * commands, including those used by the SPIBoot controller, and remains in
485  * force until the device is power-cycled.  Since the SPIBoot controller is
486  * hard-wired to use 8 dummy cycles, we must configure the device to also use 8
487  * cycles.
488  */
489 static struct seq_rw_config n25q_read3_configs[] = {
490 	{FLASH_FLAG_READ_1_4_4, SPINOR_OP_READ_1_4_4,	0, 4, 4, 0x00, 0, 8},
491 	{FLASH_FLAG_READ_1_1_4, SPINOR_OP_READ_1_1_4,	0, 1, 4, 0x00, 0, 8},
492 	{FLASH_FLAG_READ_1_2_2, SPINOR_OP_READ_1_2_2,	0, 2, 2, 0x00, 0, 8},
493 	{FLASH_FLAG_READ_1_1_2, SPINOR_OP_READ_1_1_2,	0, 1, 2, 0x00, 0, 8},
494 	{FLASH_FLAG_READ_FAST,	SPINOR_OP_READ_FAST,	0, 1, 1, 0x00, 0, 8},
495 	{FLASH_FLAG_READ_WRITE, SPINOR_OP_READ,	        0, 1, 1, 0x00, 0, 0},
496 	{0x00,			0,			0, 0, 0, 0x00, 0, 0},
497 };
498 
499 /* N25Q 4-byte Address READ configurations
500  *	- use special 4-byte address READ commands (reduces overheads, and
501  *        reduces risk of hitting watchdog reset issues).
502  *	- 'FAST' variants configured for 8 dummy cycles (see note above.)
503  */
504 static struct seq_rw_config n25q_read4_configs[] = {
505 	{FLASH_FLAG_READ_1_4_4, SPINOR_OP_READ_1_4_4_4B, 0, 4, 4, 0x00, 0, 8},
506 	{FLASH_FLAG_READ_1_1_4, SPINOR_OP_READ_1_1_4_4B, 0, 1, 4, 0x00, 0, 8},
507 	{FLASH_FLAG_READ_1_2_2, SPINOR_OP_READ_1_2_2_4B, 0, 2, 2, 0x00, 0, 8},
508 	{FLASH_FLAG_READ_1_1_2, SPINOR_OP_READ_1_1_2_4B, 0, 1, 2, 0x00, 0, 8},
509 	{FLASH_FLAG_READ_FAST,	SPINOR_OP_READ_FAST_4B,  0, 1, 1, 0x00, 0, 8},
510 	{FLASH_FLAG_READ_WRITE, SPINOR_OP_READ_4B,       0, 1, 1, 0x00, 0, 0},
511 	{0x00,			0,                       0, 0, 0, 0x00, 0, 0},
512 };
513 
514 /*
515  * [MX25xxx] Configuration
516  */
517 #define MX25_STATUS_QE			(0x1 << 6)
518 
519 static int stfsm_mx25_en_32bit_addr_seq(struct stfsm_seq *seq)
520 {
521 	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
522 			   SEQ_OPC_CYCLES(8) |
523 			   SEQ_OPC_OPCODE(SPINOR_OP_EN4B) |
524 			   SEQ_OPC_CSDEASSERT);
525 
526 	seq->seq[0] = STFSM_INST_CMD1;
527 	seq->seq[1] = STFSM_INST_WAIT;
528 	seq->seq[2] = STFSM_INST_STOP;
529 
530 	seq->seq_cfg = (SEQ_CFG_PADS_1 |
531 			SEQ_CFG_ERASE |
532 			SEQ_CFG_READNOTWRITE |
533 			SEQ_CFG_CSDEASSERT |
534 			SEQ_CFG_STARTSEQ);
535 
536 	return 0;
537 }
538 
539 /*
540  * [S25FLxxx] Configuration
541  */
542 #define STFSM_S25FL_CONFIG_QE		(0x1 << 1)
543 
544 /*
545  * S25FLxxxS devices provide three ways of supporting 32-bit addressing: Bank
546  * Register, Extended Address Modes, and a 32-bit address command set.  The
547  * 32-bit address command set is used here, since it avoids any problems with
548  * entering a state that is incompatible with the SPIBoot Controller.
549  */
550 static struct seq_rw_config stfsm_s25fl_read4_configs[] = {
551 	{FLASH_FLAG_READ_1_4_4,  SPINOR_OP_READ_1_4_4_4B,  0, 4, 4, 0x00, 2, 4},
552 	{FLASH_FLAG_READ_1_1_4,  SPINOR_OP_READ_1_1_4_4B,  0, 1, 4, 0x00, 0, 8},
553 	{FLASH_FLAG_READ_1_2_2,  SPINOR_OP_READ_1_2_2_4B,  0, 2, 2, 0x00, 4, 0},
554 	{FLASH_FLAG_READ_1_1_2,  SPINOR_OP_READ_1_1_2_4B,  0, 1, 2, 0x00, 0, 8},
555 	{FLASH_FLAG_READ_FAST,   SPINOR_OP_READ_FAST_4B,   0, 1, 1, 0x00, 0, 8},
556 	{FLASH_FLAG_READ_WRITE,  SPINOR_OP_READ_4B,        0, 1, 1, 0x00, 0, 0},
557 	{0x00,                   0,                        0, 0, 0, 0x00, 0, 0},
558 };
559 
560 static struct seq_rw_config stfsm_s25fl_write4_configs[] = {
561 	{FLASH_FLAG_WRITE_1_1_4, S25FL_CMD_WRITE4_1_1_4, 1, 1, 4, 0x00, 0, 0},
562 	{FLASH_FLAG_READ_WRITE,  S25FL_CMD_WRITE4,       1, 1, 1, 0x00, 0, 0},
563 	{0x00,                   0,                      0, 0, 0, 0x00, 0, 0},
564 };
565 
566 /*
567  * [W25Qxxx] Configuration
568  */
569 #define W25Q_STATUS_QE			(0x1 << 1)
570 
571 static struct stfsm_seq stfsm_seq_read_jedec = {
572 	.data_size = TRANSFER_SIZE(8),
573 	.seq_opc[0] = (SEQ_OPC_PADS_1 |
574 		       SEQ_OPC_CYCLES(8) |
575 		       SEQ_OPC_OPCODE(SPINOR_OP_RDID)),
576 	.seq = {
577 		STFSM_INST_CMD1,
578 		STFSM_INST_DATA_READ,
579 		STFSM_INST_STOP,
580 	},
581 	.seq_cfg = (SEQ_CFG_PADS_1 |
582 		    SEQ_CFG_READNOTWRITE |
583 		    SEQ_CFG_CSDEASSERT |
584 		    SEQ_CFG_STARTSEQ),
585 };
586 
587 static struct stfsm_seq stfsm_seq_read_status_fifo = {
588 	.data_size = TRANSFER_SIZE(4),
589 	.seq_opc[0] = (SEQ_OPC_PADS_1 |
590 		       SEQ_OPC_CYCLES(8) |
591 		       SEQ_OPC_OPCODE(SPINOR_OP_RDSR)),
592 	.seq = {
593 		STFSM_INST_CMD1,
594 		STFSM_INST_DATA_READ,
595 		STFSM_INST_STOP,
596 	},
597 	.seq_cfg = (SEQ_CFG_PADS_1 |
598 		    SEQ_CFG_READNOTWRITE |
599 		    SEQ_CFG_CSDEASSERT |
600 		    SEQ_CFG_STARTSEQ),
601 };
602 
603 static struct stfsm_seq stfsm_seq_erase_sector = {
604 	/* 'addr_cfg' configured during initialisation */
605 	.seq_opc = {
606 		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
607 		 SEQ_OPC_OPCODE(SPINOR_OP_WREN) | SEQ_OPC_CSDEASSERT),
608 
609 		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
610 		 SEQ_OPC_OPCODE(SPINOR_OP_SE)),
611 	},
612 	.seq = {
613 		STFSM_INST_CMD1,
614 		STFSM_INST_CMD2,
615 		STFSM_INST_ADD1,
616 		STFSM_INST_ADD2,
617 		STFSM_INST_STOP,
618 	},
619 	.seq_cfg = (SEQ_CFG_PADS_1 |
620 		    SEQ_CFG_READNOTWRITE |
621 		    SEQ_CFG_CSDEASSERT |
622 		    SEQ_CFG_STARTSEQ),
623 };
624 
625 static struct stfsm_seq stfsm_seq_erase_chip = {
626 	.seq_opc = {
627 		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
628 		 SEQ_OPC_OPCODE(SPINOR_OP_WREN) | SEQ_OPC_CSDEASSERT),
629 
630 		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
631 		 SEQ_OPC_OPCODE(SPINOR_OP_CHIP_ERASE) | SEQ_OPC_CSDEASSERT),
632 	},
633 	.seq = {
634 		STFSM_INST_CMD1,
635 		STFSM_INST_CMD2,
636 		STFSM_INST_WAIT,
637 		STFSM_INST_STOP,
638 	},
639 	.seq_cfg = (SEQ_CFG_PADS_1 |
640 		    SEQ_CFG_ERASE |
641 		    SEQ_CFG_READNOTWRITE |
642 		    SEQ_CFG_CSDEASSERT |
643 		    SEQ_CFG_STARTSEQ),
644 };
645 
646 static struct stfsm_seq stfsm_seq_write_status = {
647 	.seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
648 		       SEQ_OPC_OPCODE(SPINOR_OP_WREN) | SEQ_OPC_CSDEASSERT),
649 	.seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
650 		       SEQ_OPC_OPCODE(SPINOR_OP_WRSR)),
651 	.seq = {
652 		STFSM_INST_CMD1,
653 		STFSM_INST_CMD2,
654 		STFSM_INST_STA_WR1,
655 		STFSM_INST_STOP,
656 	},
657 	.seq_cfg = (SEQ_CFG_PADS_1 |
658 		    SEQ_CFG_READNOTWRITE |
659 		    SEQ_CFG_CSDEASSERT |
660 		    SEQ_CFG_STARTSEQ),
661 };
662 
663 /* Dummy sequence to read one byte of data from flash into the FIFO */
664 static const struct stfsm_seq stfsm_seq_load_fifo_byte = {
665 	.data_size = TRANSFER_SIZE(1),
666 	.seq_opc[0] = (SEQ_OPC_PADS_1 |
667 		       SEQ_OPC_CYCLES(8) |
668 		       SEQ_OPC_OPCODE(SPINOR_OP_RDID)),
669 	.seq = {
670 		STFSM_INST_CMD1,
671 		STFSM_INST_DATA_READ,
672 		STFSM_INST_STOP,
673 	},
674 	.seq_cfg = (SEQ_CFG_PADS_1 |
675 		    SEQ_CFG_READNOTWRITE |
676 		    SEQ_CFG_CSDEASSERT |
677 		    SEQ_CFG_STARTSEQ),
678 };
679 
680 static int stfsm_n25q_en_32bit_addr_seq(struct stfsm_seq *seq)
681 {
682 	seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
683 			   SEQ_OPC_OPCODE(SPINOR_OP_EN4B));
684 	seq->seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
685 			   SEQ_OPC_OPCODE(SPINOR_OP_WREN) |
686 			   SEQ_OPC_CSDEASSERT);
687 
688 	seq->seq[0] = STFSM_INST_CMD2;
689 	seq->seq[1] = STFSM_INST_CMD1;
690 	seq->seq[2] = STFSM_INST_WAIT;
691 	seq->seq[3] = STFSM_INST_STOP;
692 
693 	seq->seq_cfg = (SEQ_CFG_PADS_1 |
694 			SEQ_CFG_ERASE |
695 			SEQ_CFG_READNOTWRITE |
696 			SEQ_CFG_CSDEASSERT |
697 			SEQ_CFG_STARTSEQ);
698 
699 	return 0;
700 }
701 
702 static inline int stfsm_is_idle(struct stfsm *fsm)
703 {
704 	return readl(fsm->base + SPI_FAST_SEQ_STA) & 0x10;
705 }
706 
707 static inline uint32_t stfsm_fifo_available(struct stfsm *fsm)
708 {
709 	return (readl(fsm->base + SPI_FAST_SEQ_STA) >> 5) & 0x7f;
710 }
711 
712 static inline void stfsm_load_seq(struct stfsm *fsm,
713 				  const struct stfsm_seq *seq)
714 {
715 	void __iomem *dst = fsm->base + SPI_FAST_SEQ_TRANSFER_SIZE;
716 	const uint32_t *src = (const uint32_t *)seq;
717 	int words = sizeof(*seq) / sizeof(*src);
718 
719 	BUG_ON(!stfsm_is_idle(fsm));
720 
721 	while (words--) {
722 		writel(*src, dst);
723 		src++;
724 		dst += 4;
725 	}
726 }
727 
728 static void stfsm_wait_seq(struct stfsm *fsm)
729 {
730 	unsigned long deadline;
731 	int timeout = 0;
732 
733 	deadline = jiffies + msecs_to_jiffies(STFSM_MAX_WAIT_SEQ_MS);
734 
735 	while (!timeout) {
736 		if (time_after_eq(jiffies, deadline))
737 			timeout = 1;
738 
739 		if (stfsm_is_idle(fsm))
740 			return;
741 
742 		cond_resched();
743 	}
744 
745 	dev_err(fsm->dev, "timeout on sequence completion\n");
746 }
747 
748 static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf, uint32_t size)
749 {
750 	uint32_t remaining = size >> 2;
751 	uint32_t avail;
752 	uint32_t words;
753 
754 	dev_dbg(fsm->dev, "Reading %d bytes from FIFO\n", size);
755 
756 	BUG_ON((((uintptr_t)buf) & 0x3) || (size & 0x3));
757 
758 	while (remaining) {
759 		for (;;) {
760 			avail = stfsm_fifo_available(fsm);
761 			if (avail)
762 				break;
763 			udelay(1);
764 		}
765 		words = min(avail, remaining);
766 		remaining -= words;
767 
768 		readsl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
769 		buf += words;
770 	}
771 }
772 
773 /*
774  * Clear the data FIFO
775  *
776  * Typically, this is only required during driver initialisation, where no
777  * assumptions can be made regarding the state of the FIFO.
778  *
779  * The process of clearing the FIFO is complicated by fact that while it is
780  * possible for the FIFO to contain an arbitrary number of bytes [1], the
781  * SPI_FAST_SEQ_STA register only reports the number of complete 32-bit words
782  * present.  Furthermore, data can only be drained from the FIFO by reading
783  * complete 32-bit words.
784  *
785  * With this in mind, a two stage process is used to the clear the FIFO:
786  *
787  *     1. Read any complete 32-bit words from the FIFO, as reported by the
788  *        SPI_FAST_SEQ_STA register.
789  *
790  *     2. Mop up any remaining bytes.  At this point, it is not known if there
791  *        are 0, 1, 2, or 3 bytes in the FIFO.  To handle all cases, a dummy FSM
792  *        sequence is used to load one byte at a time, until a complete 32-bit
793  *        word is formed; at most, 4 bytes will need to be loaded.
794  *
795  * [1] It is theoretically possible for the FIFO to contain an arbitrary number
796  *     of bits.  However, since there are no known use-cases that leave
797  *     incomplete bytes in the FIFO, only words and bytes are considered here.
798  */
799 static void stfsm_clear_fifo(struct stfsm *fsm)
800 {
801 	const struct stfsm_seq *seq = &stfsm_seq_load_fifo_byte;
802 	uint32_t words, i;
803 
804 	/* 1. Clear any 32-bit words */
805 	words = stfsm_fifo_available(fsm);
806 	if (words) {
807 		for (i = 0; i < words; i++)
808 			readl(fsm->base + SPI_FAST_SEQ_DATA_REG);
809 		dev_dbg(fsm->dev, "cleared %d words from FIFO\n", words);
810 	}
811 
812 	/*
813 	 * 2. Clear any remaining bytes
814 	 *    - Load the FIFO, one byte at a time, until a complete 32-bit word
815 	 *      is available.
816 	 */
817 	for (i = 0, words = 0; i < 4 && !words; i++) {
818 		stfsm_load_seq(fsm, seq);
819 		stfsm_wait_seq(fsm);
820 		words = stfsm_fifo_available(fsm);
821 	}
822 
823 	/*    - A single word must be available now */
824 	if (words != 1) {
825 		dev_err(fsm->dev, "failed to clear bytes from the data FIFO\n");
826 		return;
827 	}
828 
829 	/*    - Read the 32-bit word */
830 	readl(fsm->base + SPI_FAST_SEQ_DATA_REG);
831 
832 	dev_dbg(fsm->dev, "cleared %d byte(s) from the data FIFO\n", 4 - i);
833 }
834 
835 static int stfsm_write_fifo(struct stfsm *fsm, const uint32_t *buf,
836 			    uint32_t size)
837 {
838 	uint32_t words = size >> 2;
839 
840 	dev_dbg(fsm->dev, "writing %d bytes to FIFO\n", size);
841 
842 	BUG_ON((((uintptr_t)buf) & 0x3) || (size & 0x3));
843 
844 	writesl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
845 
846 	return size;
847 }
848 
849 static int stfsm_enter_32bit_addr(struct stfsm *fsm, int enter)
850 {
851 	struct stfsm_seq *seq = &fsm->stfsm_seq_en_32bit_addr;
852 	uint32_t cmd = enter ? SPINOR_OP_EN4B : SPINOR_OP_EX4B;
853 
854 	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
855 			   SEQ_OPC_CYCLES(8) |
856 			   SEQ_OPC_OPCODE(cmd) |
857 			   SEQ_OPC_CSDEASSERT);
858 
859 	stfsm_load_seq(fsm, seq);
860 
861 	stfsm_wait_seq(fsm);
862 
863 	return 0;
864 }
865 
866 static uint8_t stfsm_wait_busy(struct stfsm *fsm)
867 {
868 	struct stfsm_seq *seq = &stfsm_seq_read_status_fifo;
869 	unsigned long deadline;
870 	uint32_t status;
871 	int timeout = 0;
872 
873 	/* Use RDRS1 */
874 	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
875 			   SEQ_OPC_CYCLES(8) |
876 			   SEQ_OPC_OPCODE(SPINOR_OP_RDSR));
877 
878 	/* Load read_status sequence */
879 	stfsm_load_seq(fsm, seq);
880 
881 	/*
882 	 * Repeat until busy bit is deasserted, or timeout, or error (S25FLxxxS)
883 	 */
884 	deadline = jiffies + FLASH_MAX_BUSY_WAIT;
885 	while (!timeout) {
886 		if (time_after_eq(jiffies, deadline))
887 			timeout = 1;
888 
889 		stfsm_wait_seq(fsm);
890 
891 		stfsm_read_fifo(fsm, &status, 4);
892 
893 		if ((status & FLASH_STATUS_BUSY) == 0)
894 			return 0;
895 
896 		if ((fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS) &&
897 		    ((status & S25FL_STATUS_P_ERR) ||
898 		     (status & S25FL_STATUS_E_ERR)))
899 			return (uint8_t)(status & 0xff);
900 
901 		if (!timeout)
902 			/* Restart */
903 			writel(seq->seq_cfg, fsm->base + SPI_FAST_SEQ_CFG);
904 
905 		cond_resched();
906 	}
907 
908 	dev_err(fsm->dev, "timeout on wait_busy\n");
909 
910 	return FLASH_STATUS_TIMEOUT;
911 }
912 
913 static int stfsm_read_status(struct stfsm *fsm, uint8_t cmd,
914 			     uint8_t *data, int bytes)
915 {
916 	struct stfsm_seq *seq = &stfsm_seq_read_status_fifo;
917 	uint32_t tmp;
918 	uint8_t *t = (uint8_t *)&tmp;
919 	int i;
920 
921 	dev_dbg(fsm->dev, "read 'status' register [0x%02x], %d byte(s)\n",
922 		cmd, bytes);
923 
924 	BUG_ON(bytes != 1 && bytes != 2);
925 
926 	seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
927 			   SEQ_OPC_OPCODE(cmd));
928 
929 	stfsm_load_seq(fsm, seq);
930 
931 	stfsm_read_fifo(fsm, &tmp, 4);
932 
933 	for (i = 0; i < bytes; i++)
934 		data[i] = t[i];
935 
936 	stfsm_wait_seq(fsm);
937 
938 	return 0;
939 }
940 
941 static int stfsm_write_status(struct stfsm *fsm, uint8_t cmd,
942 			    uint16_t data, int bytes, int wait_busy)
943 {
944 	struct stfsm_seq *seq = &stfsm_seq_write_status;
945 
946 	dev_dbg(fsm->dev,
947 		"write 'status' register [0x%02x], %d byte(s), 0x%04x\n"
948 		" %s wait-busy\n", cmd, bytes, data, wait_busy ? "with" : "no");
949 
950 	BUG_ON(bytes != 1 && bytes != 2);
951 
952 	seq->seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
953 			   SEQ_OPC_OPCODE(cmd));
954 
955 	seq->status = (uint32_t)data | STA_PADS_1 | STA_CSDEASSERT;
956 	seq->seq[2] = (bytes == 1) ? STFSM_INST_STA_WR1 : STFSM_INST_STA_WR1_2;
957 
958 	stfsm_load_seq(fsm, seq);
959 
960 	stfsm_wait_seq(fsm);
961 
962 	if (wait_busy)
963 		stfsm_wait_busy(fsm);
964 
965 	return 0;
966 }
967 
968 /*
969  * SoC reset on 'boot-from-spi' systems
970  *
971  * Certain modes of operation cause the Flash device to enter a particular state
972  * for a period of time (e.g. 'Erase Sector', 'Quad Enable', and 'Enter 32-bit
973  * Addr' commands).  On boot-from-spi systems, it is important to consider what
974  * happens if a warm reset occurs during this period.  The SPIBoot controller
975  * assumes that Flash device is in its default reset state, 24-bit address mode,
976  * and ready to accept commands.  This can be achieved using some form of
977  * on-board logic/controller to force a device POR in response to a SoC-level
978  * reset or by making use of the device reset signal if available (limited
979  * number of devices only).
980  *
981  * Failure to take such precautions can cause problems following a warm reset.
982  * For some operations (e.g. ERASE), there is little that can be done.  For
983  * other modes of operation (e.g. 32-bit addressing), options are often
984  * available that can help minimise the window in which a reset could cause a
985  * problem.
986  *
987  */
988 static bool stfsm_can_handle_soc_reset(struct stfsm *fsm)
989 {
990 	/* Reset signal is available on the board and supported by the device */
991 	if (fsm->reset_signal && fsm->info->flags & FLASH_FLAG_RESET)
992 		return true;
993 
994 	/* Board-level logic forces a power-on-reset */
995 	if (fsm->reset_por)
996 		return true;
997 
998 	/* Reset is not properly handled and may result in failure to reboot */
999 	return false;
1000 }
1001 
1002 /* Configure 'addr_cfg' according to addressing mode */
1003 static void stfsm_prepare_erasesec_seq(struct stfsm *fsm,
1004 				       struct stfsm_seq *seq)
1005 {
1006 	int addr1_cycles = fsm->info->flags & FLASH_FLAG_32BIT_ADDR ? 16 : 8;
1007 
1008 	seq->addr_cfg = (ADR_CFG_CYCLES_ADD1(addr1_cycles) |
1009 			 ADR_CFG_PADS_1_ADD1 |
1010 			 ADR_CFG_CYCLES_ADD2(16) |
1011 			 ADR_CFG_PADS_1_ADD2 |
1012 			 ADR_CFG_CSDEASSERT_ADD2);
1013 }
1014 
1015 /* Search for preferred configuration based on available flags */
1016 static struct seq_rw_config *
1017 stfsm_search_seq_rw_configs(struct stfsm *fsm,
1018 			    struct seq_rw_config cfgs[])
1019 {
1020 	struct seq_rw_config *config;
1021 	int flags = fsm->info->flags;
1022 
1023 	for (config = cfgs; config->cmd != 0; config++)
1024 		if ((config->flags & flags) == config->flags)
1025 			return config;
1026 
1027 	return NULL;
1028 }
1029 
1030 /* Prepare a READ/WRITE sequence according to configuration parameters */
1031 static void stfsm_prepare_rw_seq(struct stfsm *fsm,
1032 				 struct stfsm_seq *seq,
1033 				 struct seq_rw_config *cfg)
1034 {
1035 	int addr1_cycles, addr2_cycles;
1036 	int i = 0;
1037 
1038 	memset(seq, 0, sizeof(*seq));
1039 
1040 	/* Add READ/WRITE OPC  */
1041 	seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
1042 			     SEQ_OPC_CYCLES(8) |
1043 			     SEQ_OPC_OPCODE(cfg->cmd));
1044 
1045 	/* Add WREN OPC for a WRITE sequence */
1046 	if (cfg->write)
1047 		seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
1048 				     SEQ_OPC_CYCLES(8) |
1049 				     SEQ_OPC_OPCODE(SPINOR_OP_WREN) |
1050 				     SEQ_OPC_CSDEASSERT);
1051 
1052 	/* Address configuration (24 or 32-bit addresses) */
1053 	addr1_cycles  = (fsm->info->flags & FLASH_FLAG_32BIT_ADDR) ? 16 : 8;
1054 	addr1_cycles /= cfg->addr_pads;
1055 	addr2_cycles  = 16 / cfg->addr_pads;
1056 	seq->addr_cfg = ((addr1_cycles & 0x3f) << 0 |	/* ADD1 cycles */
1057 			 (cfg->addr_pads - 1) << 6 |	/* ADD1 pads */
1058 			 (addr2_cycles & 0x3f) << 16 |	/* ADD2 cycles */
1059 			 ((cfg->addr_pads - 1) << 22));	/* ADD2 pads */
1060 
1061 	/* Data/Sequence configuration */
1062 	seq->seq_cfg = ((cfg->data_pads - 1) << 16 |
1063 			SEQ_CFG_STARTSEQ |
1064 			SEQ_CFG_CSDEASSERT);
1065 	if (!cfg->write)
1066 		seq->seq_cfg |= SEQ_CFG_READNOTWRITE;
1067 
1068 	/* Mode configuration (no. of pads taken from addr cfg) */
1069 	seq->mode = ((cfg->mode_data & 0xff) << 0 |	/* data */
1070 		     (cfg->mode_cycles & 0x3f) << 16 |	/* cycles */
1071 		     (cfg->addr_pads - 1) << 22);	/* pads */
1072 
1073 	/* Dummy configuration (no. of pads taken from addr cfg) */
1074 	seq->dummy = ((cfg->dummy_cycles & 0x3f) << 16 |	/* cycles */
1075 		      (cfg->addr_pads - 1) << 22);		/* pads */
1076 
1077 
1078 	/* Instruction sequence */
1079 	i = 0;
1080 	if (cfg->write)
1081 		seq->seq[i++] = STFSM_INST_CMD2;
1082 
1083 	seq->seq[i++] = STFSM_INST_CMD1;
1084 
1085 	seq->seq[i++] = STFSM_INST_ADD1;
1086 	seq->seq[i++] = STFSM_INST_ADD2;
1087 
1088 	if (cfg->mode_cycles)
1089 		seq->seq[i++] = STFSM_INST_MODE;
1090 
1091 	if (cfg->dummy_cycles)
1092 		seq->seq[i++] = STFSM_INST_DUMMY;
1093 
1094 	seq->seq[i++] =
1095 		cfg->write ? STFSM_INST_DATA_WRITE : STFSM_INST_DATA_READ;
1096 	seq->seq[i++] = STFSM_INST_STOP;
1097 }
1098 
1099 static int stfsm_search_prepare_rw_seq(struct stfsm *fsm,
1100 				       struct stfsm_seq *seq,
1101 				       struct seq_rw_config *cfgs)
1102 {
1103 	struct seq_rw_config *config;
1104 
1105 	config = stfsm_search_seq_rw_configs(fsm, cfgs);
1106 	if (!config) {
1107 		dev_err(fsm->dev, "failed to find suitable config\n");
1108 		return -EINVAL;
1109 	}
1110 
1111 	stfsm_prepare_rw_seq(fsm, seq, config);
1112 
1113 	return 0;
1114 }
1115 
1116 /* Prepare a READ/WRITE/ERASE 'default' sequences */
1117 static int stfsm_prepare_rwe_seqs_default(struct stfsm *fsm)
1118 {
1119 	uint32_t flags = fsm->info->flags;
1120 	int ret;
1121 
1122 	/* Configure 'READ' sequence */
1123 	ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
1124 					  default_read_configs);
1125 	if (ret) {
1126 		dev_err(fsm->dev,
1127 			"failed to prep READ sequence with flags [0x%08x]\n",
1128 			flags);
1129 		return ret;
1130 	}
1131 
1132 	/* Configure 'WRITE' sequence */
1133 	ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_write,
1134 					  default_write_configs);
1135 	if (ret) {
1136 		dev_err(fsm->dev,
1137 			"failed to prep WRITE sequence with flags [0x%08x]\n",
1138 			flags);
1139 		return ret;
1140 	}
1141 
1142 	/* Configure 'ERASE_SECTOR' sequence */
1143 	stfsm_prepare_erasesec_seq(fsm, &stfsm_seq_erase_sector);
1144 
1145 	return 0;
1146 }
1147 
1148 static int stfsm_mx25_config(struct stfsm *fsm)
1149 {
1150 	uint32_t flags = fsm->info->flags;
1151 	uint32_t data_pads;
1152 	uint8_t sta;
1153 	int ret;
1154 	bool soc_reset;
1155 
1156 	/*
1157 	 * Use default READ/WRITE sequences
1158 	 */
1159 	ret = stfsm_prepare_rwe_seqs_default(fsm);
1160 	if (ret)
1161 		return ret;
1162 
1163 	/*
1164 	 * Configure 32-bit Address Support
1165 	 */
1166 	if (flags & FLASH_FLAG_32BIT_ADDR) {
1167 		/* Configure 'enter_32bitaddr' FSM sequence */
1168 		stfsm_mx25_en_32bit_addr_seq(&fsm->stfsm_seq_en_32bit_addr);
1169 
1170 		soc_reset = stfsm_can_handle_soc_reset(fsm);
1171 		if (soc_reset || !fsm->booted_from_spi)
1172 			/* If we can handle SoC resets, we enable 32-bit address
1173 			 * mode pervasively */
1174 			stfsm_enter_32bit_addr(fsm, 1);
1175 
1176 		else
1177 			/* Else, enable/disable 32-bit addressing before/after
1178 			 * each operation */
1179 			fsm->configuration = (CFG_READ_TOGGLE_32BIT_ADDR |
1180 					      CFG_WRITE_TOGGLE_32BIT_ADDR |
1181 					      CFG_ERASESEC_TOGGLE_32BIT_ADDR);
1182 	}
1183 
1184 	/* Check status of 'QE' bit, update if required. */
1185 	stfsm_read_status(fsm, SPINOR_OP_RDSR, &sta, 1);
1186 	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
1187 	if (data_pads == 4) {
1188 		if (!(sta & MX25_STATUS_QE)) {
1189 			/* Set 'QE' */
1190 			sta |= MX25_STATUS_QE;
1191 
1192 			stfsm_write_status(fsm, SPINOR_OP_WRSR, sta, 1, 1);
1193 		}
1194 	} else {
1195 		if (sta & MX25_STATUS_QE) {
1196 			/* Clear 'QE' */
1197 			sta &= ~MX25_STATUS_QE;
1198 
1199 			stfsm_write_status(fsm, SPINOR_OP_WRSR, sta, 1, 1);
1200 		}
1201 	}
1202 
1203 	return 0;
1204 }
1205 
1206 static int stfsm_n25q_config(struct stfsm *fsm)
1207 {
1208 	uint32_t flags = fsm->info->flags;
1209 	uint8_t vcr;
1210 	int ret = 0;
1211 	bool soc_reset;
1212 
1213 	/* Configure 'READ' sequence */
1214 	if (flags & FLASH_FLAG_32BIT_ADDR)
1215 		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
1216 						  n25q_read4_configs);
1217 	else
1218 		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
1219 						  n25q_read3_configs);
1220 	if (ret) {
1221 		dev_err(fsm->dev,
1222 			"failed to prepare READ sequence with flags [0x%08x]\n",
1223 			flags);
1224 		return ret;
1225 	}
1226 
1227 	/* Configure 'WRITE' sequence (default configs) */
1228 	ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_write,
1229 					  default_write_configs);
1230 	if (ret) {
1231 		dev_err(fsm->dev,
1232 			"preparing WRITE sequence using flags [0x%08x] failed\n",
1233 			flags);
1234 		return ret;
1235 	}
1236 
1237 	/* * Configure 'ERASE_SECTOR' sequence */
1238 	stfsm_prepare_erasesec_seq(fsm, &stfsm_seq_erase_sector);
1239 
1240 	/* Configure 32-bit address support */
1241 	if (flags & FLASH_FLAG_32BIT_ADDR) {
1242 		stfsm_n25q_en_32bit_addr_seq(&fsm->stfsm_seq_en_32bit_addr);
1243 
1244 		soc_reset = stfsm_can_handle_soc_reset(fsm);
1245 		if (soc_reset || !fsm->booted_from_spi) {
1246 			/*
1247 			 * If we can handle SoC resets, we enable 32-bit
1248 			 * address mode pervasively
1249 			 */
1250 			stfsm_enter_32bit_addr(fsm, 1);
1251 		} else {
1252 			/*
1253 			 * If not, enable/disable for WRITE and ERASE
1254 			 * operations (READ uses special commands)
1255 			 */
1256 			fsm->configuration = (CFG_WRITE_TOGGLE_32BIT_ADDR |
1257 					      CFG_ERASESEC_TOGGLE_32BIT_ADDR);
1258 		}
1259 	}
1260 
1261 	/*
1262 	 * Configure device to use 8 dummy cycles
1263 	 */
1264 	vcr = (N25Q_VCR_DUMMY_CYCLES(8) | N25Q_VCR_XIP_DISABLED |
1265 	       N25Q_VCR_WRAP_CONT);
1266 	stfsm_write_status(fsm, N25Q_CMD_WRVCR, vcr, 1, 0);
1267 
1268 	return 0;
1269 }
1270 
1271 static void stfsm_s25fl_prepare_erasesec_seq_32(struct stfsm_seq *seq)
1272 {
1273 	seq->seq_opc[1] = (SEQ_OPC_PADS_1 |
1274 			   SEQ_OPC_CYCLES(8) |
1275 			   SEQ_OPC_OPCODE(S25FL_CMD_SE4));
1276 
1277 	seq->addr_cfg = (ADR_CFG_CYCLES_ADD1(16) |
1278 			 ADR_CFG_PADS_1_ADD1 |
1279 			 ADR_CFG_CYCLES_ADD2(16) |
1280 			 ADR_CFG_PADS_1_ADD2 |
1281 			 ADR_CFG_CSDEASSERT_ADD2);
1282 }
1283 
1284 static void stfsm_s25fl_read_dyb(struct stfsm *fsm, uint32_t offs, uint8_t *dby)
1285 {
1286 	uint32_t tmp;
1287 	struct stfsm_seq seq = {
1288 		.data_size = TRANSFER_SIZE(4),
1289 		.seq_opc[0] = (SEQ_OPC_PADS_1 |
1290 			       SEQ_OPC_CYCLES(8) |
1291 			       SEQ_OPC_OPCODE(S25FL_CMD_DYBRD)),
1292 		.addr_cfg = (ADR_CFG_CYCLES_ADD1(16) |
1293 			     ADR_CFG_PADS_1_ADD1 |
1294 			     ADR_CFG_CYCLES_ADD2(16) |
1295 			     ADR_CFG_PADS_1_ADD2),
1296 		.addr1 = (offs >> 16) & 0xffff,
1297 		.addr2 = offs & 0xffff,
1298 		.seq = {
1299 			STFSM_INST_CMD1,
1300 			STFSM_INST_ADD1,
1301 			STFSM_INST_ADD2,
1302 			STFSM_INST_DATA_READ,
1303 			STFSM_INST_STOP,
1304 		},
1305 		.seq_cfg = (SEQ_CFG_PADS_1 |
1306 			    SEQ_CFG_READNOTWRITE |
1307 			    SEQ_CFG_CSDEASSERT |
1308 			    SEQ_CFG_STARTSEQ),
1309 	};
1310 
1311 	stfsm_load_seq(fsm, &seq);
1312 
1313 	stfsm_read_fifo(fsm, &tmp, 4);
1314 
1315 	*dby = (uint8_t)(tmp >> 24);
1316 
1317 	stfsm_wait_seq(fsm);
1318 }
1319 
1320 static void stfsm_s25fl_write_dyb(struct stfsm *fsm, uint32_t offs, uint8_t dby)
1321 {
1322 	struct stfsm_seq seq = {
1323 		.seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
1324 			       SEQ_OPC_OPCODE(SPINOR_OP_WREN) |
1325 			       SEQ_OPC_CSDEASSERT),
1326 		.seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
1327 			       SEQ_OPC_OPCODE(S25FL_CMD_DYBWR)),
1328 		.addr_cfg = (ADR_CFG_CYCLES_ADD1(16) |
1329 			     ADR_CFG_PADS_1_ADD1 |
1330 			     ADR_CFG_CYCLES_ADD2(16) |
1331 			     ADR_CFG_PADS_1_ADD2),
1332 		.status = (uint32_t)dby | STA_PADS_1 | STA_CSDEASSERT,
1333 		.addr1 = (offs >> 16) & 0xffff,
1334 		.addr2 = offs & 0xffff,
1335 		.seq = {
1336 			STFSM_INST_CMD1,
1337 			STFSM_INST_CMD2,
1338 			STFSM_INST_ADD1,
1339 			STFSM_INST_ADD2,
1340 			STFSM_INST_STA_WR1,
1341 			STFSM_INST_STOP,
1342 		},
1343 		.seq_cfg = (SEQ_CFG_PADS_1 |
1344 			    SEQ_CFG_READNOTWRITE |
1345 			    SEQ_CFG_CSDEASSERT |
1346 			    SEQ_CFG_STARTSEQ),
1347 	};
1348 
1349 	stfsm_load_seq(fsm, &seq);
1350 	stfsm_wait_seq(fsm);
1351 
1352 	stfsm_wait_busy(fsm);
1353 }
1354 
1355 static int stfsm_s25fl_clear_status_reg(struct stfsm *fsm)
1356 {
1357 	struct stfsm_seq seq = {
1358 		.seq_opc[0] = (SEQ_OPC_PADS_1 |
1359 			       SEQ_OPC_CYCLES(8) |
1360 			       SEQ_OPC_OPCODE(S25FL_CMD_CLSR) |
1361 			       SEQ_OPC_CSDEASSERT),
1362 		.seq_opc[1] = (SEQ_OPC_PADS_1 |
1363 			       SEQ_OPC_CYCLES(8) |
1364 			       SEQ_OPC_OPCODE(SPINOR_OP_WRDI) |
1365 			       SEQ_OPC_CSDEASSERT),
1366 		.seq = {
1367 			STFSM_INST_CMD1,
1368 			STFSM_INST_CMD2,
1369 			STFSM_INST_WAIT,
1370 			STFSM_INST_STOP,
1371 		},
1372 		.seq_cfg = (SEQ_CFG_PADS_1 |
1373 			    SEQ_CFG_ERASE |
1374 			    SEQ_CFG_READNOTWRITE |
1375 			    SEQ_CFG_CSDEASSERT |
1376 			    SEQ_CFG_STARTSEQ),
1377 	};
1378 
1379 	stfsm_load_seq(fsm, &seq);
1380 
1381 	stfsm_wait_seq(fsm);
1382 
1383 	return 0;
1384 }
1385 
1386 static int stfsm_s25fl_config(struct stfsm *fsm)
1387 {
1388 	struct flash_info *info = fsm->info;
1389 	uint32_t flags = info->flags;
1390 	uint32_t data_pads;
1391 	uint32_t offs;
1392 	uint16_t sta_wr;
1393 	uint8_t sr1, cr1, dyb;
1394 	int update_sr = 0;
1395 	int ret;
1396 
1397 	if (flags & FLASH_FLAG_32BIT_ADDR) {
1398 		/*
1399 		 * Prepare Read/Write/Erase sequences according to S25FLxxx
1400 		 * 32-bit address command set
1401 		 */
1402 		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
1403 						  stfsm_s25fl_read4_configs);
1404 		if (ret)
1405 			return ret;
1406 
1407 		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_write,
1408 						  stfsm_s25fl_write4_configs);
1409 		if (ret)
1410 			return ret;
1411 
1412 		stfsm_s25fl_prepare_erasesec_seq_32(&stfsm_seq_erase_sector);
1413 
1414 	} else {
1415 		/* Use default configurations for 24-bit addressing */
1416 		ret = stfsm_prepare_rwe_seqs_default(fsm);
1417 		if (ret)
1418 			return ret;
1419 	}
1420 
1421 	/*
1422 	 * For devices that support 'DYB' sector locking, check lock status and
1423 	 * unlock sectors if necessary (some variants power-on with sectors
1424 	 * locked by default)
1425 	 */
1426 	if (flags & FLASH_FLAG_DYB_LOCKING) {
1427 		offs = 0;
1428 		for (offs = 0; offs < info->sector_size * info->n_sectors;) {
1429 			stfsm_s25fl_read_dyb(fsm, offs, &dyb);
1430 			if (dyb == 0x00)
1431 				stfsm_s25fl_write_dyb(fsm, offs, 0xff);
1432 
1433 			/* Handle bottom/top 4KiB parameter sectors */
1434 			if ((offs < info->sector_size * 2) ||
1435 			    (offs >= (info->sector_size - info->n_sectors * 4)))
1436 				offs += 0x1000;
1437 			else
1438 				offs += 0x10000;
1439 		}
1440 	}
1441 
1442 	/* Check status of 'QE' bit, update if required. */
1443 	stfsm_read_status(fsm, SPINOR_OP_RDCR, &cr1, 1);
1444 	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
1445 	if (data_pads == 4) {
1446 		if (!(cr1 & STFSM_S25FL_CONFIG_QE)) {
1447 			/* Set 'QE' */
1448 			cr1 |= STFSM_S25FL_CONFIG_QE;
1449 
1450 			update_sr = 1;
1451 		}
1452 	} else {
1453 		if (cr1 & STFSM_S25FL_CONFIG_QE) {
1454 			/* Clear 'QE' */
1455 			cr1 &= ~STFSM_S25FL_CONFIG_QE;
1456 
1457 			update_sr = 1;
1458 		}
1459 	}
1460 	if (update_sr) {
1461 		stfsm_read_status(fsm, SPINOR_OP_RDSR, &sr1, 1);
1462 		sta_wr = ((uint16_t)cr1  << 8) | sr1;
1463 		stfsm_write_status(fsm, SPINOR_OP_WRSR, sta_wr, 2, 1);
1464 	}
1465 
1466 	/*
1467 	 * S25FLxxx devices support Program and Error error flags.
1468 	 * Configure driver to check flags and clear if necessary.
1469 	 */
1470 	fsm->configuration |= CFG_S25FL_CHECK_ERROR_FLAGS;
1471 
1472 	return 0;
1473 }
1474 
1475 static int stfsm_w25q_config(struct stfsm *fsm)
1476 {
1477 	uint32_t data_pads;
1478 	uint8_t sr1, sr2;
1479 	uint16_t sr_wr;
1480 	int update_sr = 0;
1481 	int ret;
1482 
1483 	ret = stfsm_prepare_rwe_seqs_default(fsm);
1484 	if (ret)
1485 		return ret;
1486 
1487 	/* Check status of 'QE' bit, update if required. */
1488 	stfsm_read_status(fsm, SPINOR_OP_RDCR, &sr2, 1);
1489 	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
1490 	if (data_pads == 4) {
1491 		if (!(sr2 & W25Q_STATUS_QE)) {
1492 			/* Set 'QE' */
1493 			sr2 |= W25Q_STATUS_QE;
1494 			update_sr = 1;
1495 		}
1496 	} else {
1497 		if (sr2 & W25Q_STATUS_QE) {
1498 			/* Clear 'QE' */
1499 			sr2 &= ~W25Q_STATUS_QE;
1500 			update_sr = 1;
1501 		}
1502 	}
1503 	if (update_sr) {
1504 		/* Write status register */
1505 		stfsm_read_status(fsm, SPINOR_OP_RDSR, &sr1, 1);
1506 		sr_wr = ((uint16_t)sr2 << 8) | sr1;
1507 		stfsm_write_status(fsm, SPINOR_OP_WRSR, sr_wr, 2, 1);
1508 	}
1509 
1510 	return 0;
1511 }
1512 
1513 static int stfsm_read(struct stfsm *fsm, uint8_t *buf, uint32_t size,
1514 		      uint32_t offset)
1515 {
1516 	struct stfsm_seq *seq = &fsm->stfsm_seq_read;
1517 	uint32_t data_pads;
1518 	uint32_t read_mask;
1519 	uint32_t size_ub;
1520 	uint32_t size_lb;
1521 	uint32_t size_mop;
1522 	uint32_t tmp[4];
1523 	uint32_t page_buf[FLASH_PAGESIZE_32];
1524 	uint8_t *p;
1525 
1526 	dev_dbg(fsm->dev, "reading %d bytes from 0x%08x\n", size, offset);
1527 
1528 	/* Enter 32-bit address mode, if required */
1529 	if (fsm->configuration & CFG_READ_TOGGLE_32BIT_ADDR)
1530 		stfsm_enter_32bit_addr(fsm, 1);
1531 
1532 	/* Must read in multiples of 32 cycles (or 32*pads/8 Bytes) */
1533 	data_pads = ((seq->seq_cfg >> 16) & 0x3) + 1;
1534 	read_mask = (data_pads << 2) - 1;
1535 
1536 	/* Handle non-aligned buf */
1537 	p = ((uintptr_t)buf & 0x3) ? (uint8_t *)page_buf : buf;
1538 
1539 	/* Handle non-aligned size */
1540 	size_ub = (size + read_mask) & ~read_mask;
1541 	size_lb = size & ~read_mask;
1542 	size_mop = size & read_mask;
1543 
1544 	seq->data_size = TRANSFER_SIZE(size_ub);
1545 	seq->addr1 = (offset >> 16) & 0xffff;
1546 	seq->addr2 = offset & 0xffff;
1547 
1548 	stfsm_load_seq(fsm, seq);
1549 
1550 	if (size_lb)
1551 		stfsm_read_fifo(fsm, (uint32_t *)p, size_lb);
1552 
1553 	if (size_mop) {
1554 		stfsm_read_fifo(fsm, tmp, read_mask + 1);
1555 		memcpy(p + size_lb, &tmp, size_mop);
1556 	}
1557 
1558 	/* Handle non-aligned buf */
1559 	if ((uintptr_t)buf & 0x3)
1560 		memcpy(buf, page_buf, size);
1561 
1562 	/* Wait for sequence to finish */
1563 	stfsm_wait_seq(fsm);
1564 
1565 	stfsm_clear_fifo(fsm);
1566 
1567 	/* Exit 32-bit address mode, if required */
1568 	if (fsm->configuration & CFG_READ_TOGGLE_32BIT_ADDR)
1569 		stfsm_enter_32bit_addr(fsm, 0);
1570 
1571 	return 0;
1572 }
1573 
1574 static int stfsm_write(struct stfsm *fsm, const uint8_t *buf,
1575 		       uint32_t size, uint32_t offset)
1576 {
1577 	struct stfsm_seq *seq = &fsm->stfsm_seq_write;
1578 	uint32_t data_pads;
1579 	uint32_t write_mask;
1580 	uint32_t size_ub;
1581 	uint32_t size_lb;
1582 	uint32_t size_mop;
1583 	uint32_t tmp[4];
1584 	uint32_t i;
1585 	uint32_t page_buf[FLASH_PAGESIZE_32];
1586 	uint8_t *t = (uint8_t *)&tmp;
1587 	const uint8_t *p;
1588 	int ret;
1589 
1590 	dev_dbg(fsm->dev, "writing %d bytes to 0x%08x\n", size, offset);
1591 
1592 	/* Enter 32-bit address mode, if required */
1593 	if (fsm->configuration & CFG_WRITE_TOGGLE_32BIT_ADDR)
1594 		stfsm_enter_32bit_addr(fsm, 1);
1595 
1596 	/* Must write in multiples of 32 cycles (or 32*pads/8 bytes) */
1597 	data_pads = ((seq->seq_cfg >> 16) & 0x3) + 1;
1598 	write_mask = (data_pads << 2) - 1;
1599 
1600 	/* Handle non-aligned buf */
1601 	if ((uintptr_t)buf & 0x3) {
1602 		memcpy(page_buf, buf, size);
1603 		p = (uint8_t *)page_buf;
1604 	} else {
1605 		p = buf;
1606 	}
1607 
1608 	/* Handle non-aligned size */
1609 	size_ub = (size + write_mask) & ~write_mask;
1610 	size_lb = size & ~write_mask;
1611 	size_mop = size & write_mask;
1612 
1613 	seq->data_size = TRANSFER_SIZE(size_ub);
1614 	seq->addr1 = (offset >> 16) & 0xffff;
1615 	seq->addr2 = offset & 0xffff;
1616 
1617 	/* Need to set FIFO to write mode, before writing data to FIFO (see
1618 	 * GNBvb79594)
1619 	 */
1620 	writel(0x00040000, fsm->base + SPI_FAST_SEQ_CFG);
1621 
1622 	/*
1623 	 * Before writing data to the FIFO, apply a small delay to allow a
1624 	 * potential change of FIFO direction to complete.
1625 	 */
1626 	if (fsm->fifo_dir_delay == 0)
1627 		readl(fsm->base + SPI_FAST_SEQ_CFG);
1628 	else
1629 		udelay(fsm->fifo_dir_delay);
1630 
1631 
1632 	/* Write data to FIFO, before starting sequence (see GNBvd79593) */
1633 	if (size_lb) {
1634 		stfsm_write_fifo(fsm, (uint32_t *)p, size_lb);
1635 		p += size_lb;
1636 	}
1637 
1638 	/* Handle non-aligned size */
1639 	if (size_mop) {
1640 		memset(t, 0xff, write_mask + 1);	/* fill with 0xff's */
1641 		for (i = 0; i < size_mop; i++)
1642 			t[i] = *p++;
1643 
1644 		stfsm_write_fifo(fsm, tmp, write_mask + 1);
1645 	}
1646 
1647 	/* Start sequence */
1648 	stfsm_load_seq(fsm, seq);
1649 
1650 	/* Wait for sequence to finish */
1651 	stfsm_wait_seq(fsm);
1652 
1653 	/* Wait for completion */
1654 	ret = stfsm_wait_busy(fsm);
1655 	if (ret && fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS)
1656 		stfsm_s25fl_clear_status_reg(fsm);
1657 
1658 	/* Exit 32-bit address mode, if required */
1659 	if (fsm->configuration & CFG_WRITE_TOGGLE_32BIT_ADDR)
1660 		stfsm_enter_32bit_addr(fsm, 0);
1661 
1662 	return 0;
1663 }
1664 
1665 /*
1666  * Read an address range from the flash chip. The address range
1667  * may be any size provided it is within the physical boundaries.
1668  */
1669 static int stfsm_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
1670 			  size_t *retlen, u_char *buf)
1671 {
1672 	struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
1673 	uint32_t bytes;
1674 
1675 	dev_dbg(fsm->dev, "%s from 0x%08x, len %zd\n",
1676 		__func__, (u32)from, len);
1677 
1678 	mutex_lock(&fsm->lock);
1679 
1680 	while (len > 0) {
1681 		bytes = min_t(size_t, len, FLASH_PAGESIZE);
1682 
1683 		stfsm_read(fsm, buf, bytes, from);
1684 
1685 		buf += bytes;
1686 		from += bytes;
1687 		len -= bytes;
1688 
1689 		*retlen += bytes;
1690 	}
1691 
1692 	mutex_unlock(&fsm->lock);
1693 
1694 	return 0;
1695 }
1696 
1697 static int stfsm_erase_sector(struct stfsm *fsm, uint32_t offset)
1698 {
1699 	struct stfsm_seq *seq = &stfsm_seq_erase_sector;
1700 	int ret;
1701 
1702 	dev_dbg(fsm->dev, "erasing sector at 0x%08x\n", offset);
1703 
1704 	/* Enter 32-bit address mode, if required */
1705 	if (fsm->configuration & CFG_ERASESEC_TOGGLE_32BIT_ADDR)
1706 		stfsm_enter_32bit_addr(fsm, 1);
1707 
1708 	seq->addr1 = (offset >> 16) & 0xffff;
1709 	seq->addr2 = offset & 0xffff;
1710 
1711 	stfsm_load_seq(fsm, seq);
1712 
1713 	stfsm_wait_seq(fsm);
1714 
1715 	/* Wait for completion */
1716 	ret = stfsm_wait_busy(fsm);
1717 	if (ret && fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS)
1718 		stfsm_s25fl_clear_status_reg(fsm);
1719 
1720 	/* Exit 32-bit address mode, if required */
1721 	if (fsm->configuration & CFG_ERASESEC_TOGGLE_32BIT_ADDR)
1722 		stfsm_enter_32bit_addr(fsm, 0);
1723 
1724 	return ret;
1725 }
1726 
1727 static int stfsm_erase_chip(struct stfsm *fsm)
1728 {
1729 	const struct stfsm_seq *seq = &stfsm_seq_erase_chip;
1730 
1731 	dev_dbg(fsm->dev, "erasing chip\n");
1732 
1733 	stfsm_load_seq(fsm, seq);
1734 
1735 	stfsm_wait_seq(fsm);
1736 
1737 	return stfsm_wait_busy(fsm);
1738 }
1739 
1740 /*
1741  * Write an address range to the flash chip.  Data must be written in
1742  * FLASH_PAGESIZE chunks.  The address range may be any size provided
1743  * it is within the physical boundaries.
1744  */
1745 static int stfsm_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
1746 			   size_t *retlen, const u_char *buf)
1747 {
1748 	struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
1749 
1750 	u32 page_offs;
1751 	u32 bytes;
1752 	uint8_t *b = (uint8_t *)buf;
1753 	int ret = 0;
1754 
1755 	dev_dbg(fsm->dev, "%s to 0x%08x, len %zd\n", __func__, (u32)to, len);
1756 
1757 	/* Offset within page */
1758 	page_offs = to % FLASH_PAGESIZE;
1759 
1760 	mutex_lock(&fsm->lock);
1761 
1762 	while (len) {
1763 		/* Write up to page boundary */
1764 		bytes = min_t(size_t, FLASH_PAGESIZE - page_offs, len);
1765 
1766 		ret = stfsm_write(fsm, b, bytes, to);
1767 		if (ret)
1768 			goto out1;
1769 
1770 		b += bytes;
1771 		len -= bytes;
1772 		to += bytes;
1773 
1774 		/* We are now page-aligned */
1775 		page_offs = 0;
1776 
1777 		*retlen += bytes;
1778 
1779 	}
1780 
1781 out1:
1782 	mutex_unlock(&fsm->lock);
1783 
1784 	return ret;
1785 }
1786 
1787 /*
1788  * Erase an address range on the flash chip. The address range may extend
1789  * one or more erase sectors.  Return an error is there is a problem erasing.
1790  */
1791 static int stfsm_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1792 {
1793 	struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
1794 	u32 addr, len;
1795 	int ret;
1796 
1797 	dev_dbg(fsm->dev, "%s at 0x%llx, len %lld\n", __func__,
1798 		(long long)instr->addr, (long long)instr->len);
1799 
1800 	addr = instr->addr;
1801 	len = instr->len;
1802 
1803 	mutex_lock(&fsm->lock);
1804 
1805 	/* Whole-chip erase? */
1806 	if (len == mtd->size) {
1807 		ret = stfsm_erase_chip(fsm);
1808 		if (ret)
1809 			goto out1;
1810 	} else {
1811 		while (len) {
1812 			ret = stfsm_erase_sector(fsm, addr);
1813 			if (ret)
1814 				goto out1;
1815 
1816 			addr += mtd->erasesize;
1817 			len -= mtd->erasesize;
1818 		}
1819 	}
1820 
1821 	mutex_unlock(&fsm->lock);
1822 
1823 	return 0;
1824 
1825 out1:
1826 	mutex_unlock(&fsm->lock);
1827 
1828 	return ret;
1829 }
1830 
1831 static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *jedec)
1832 {
1833 	const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
1834 	uint32_t tmp[2];
1835 
1836 	stfsm_load_seq(fsm, seq);
1837 
1838 	stfsm_read_fifo(fsm, tmp, 8);
1839 
1840 	memcpy(jedec, tmp, 5);
1841 
1842 	stfsm_wait_seq(fsm);
1843 }
1844 
1845 static struct flash_info *stfsm_jedec_probe(struct stfsm *fsm)
1846 {
1847 	struct flash_info	*info;
1848 	u16                     ext_jedec;
1849 	u32			jedec;
1850 	u8			id[5];
1851 
1852 	stfsm_read_jedec(fsm, id);
1853 
1854 	jedec     = id[0] << 16 | id[1] << 8 | id[2];
1855 	/*
1856 	 * JEDEC also defines an optional "extended device information"
1857 	 * string for after vendor-specific data, after the three bytes
1858 	 * we use here. Supporting some chips might require using it.
1859 	 */
1860 	ext_jedec = id[3] << 8  | id[4];
1861 
1862 	dev_dbg(fsm->dev, "JEDEC =  0x%08x [%5ph]\n", jedec, id);
1863 
1864 	for (info = flash_types; info->name; info++) {
1865 		if (info->jedec_id == jedec) {
1866 			if (info->ext_id && info->ext_id != ext_jedec)
1867 				continue;
1868 			return info;
1869 		}
1870 	}
1871 	dev_err(fsm->dev, "Unrecognized JEDEC id %06x\n", jedec);
1872 
1873 	return NULL;
1874 }
1875 
1876 static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode)
1877 {
1878 	int ret, timeout = 10;
1879 
1880 	/* Wait for controller to accept mode change */
1881 	while (--timeout) {
1882 		ret = readl(fsm->base + SPI_STA_MODE_CHANGE);
1883 		if (ret & 0x1)
1884 			break;
1885 		udelay(1);
1886 	}
1887 
1888 	if (!timeout)
1889 		return -EBUSY;
1890 
1891 	writel(mode, fsm->base + SPI_MODESELECT);
1892 
1893 	return 0;
1894 }
1895 
1896 static void stfsm_set_freq(struct stfsm *fsm, uint32_t spi_freq)
1897 {
1898 	uint32_t emi_freq;
1899 	uint32_t clk_div;
1900 
1901 	emi_freq = clk_get_rate(fsm->clk);
1902 
1903 	/*
1904 	 * Calculate clk_div - values between 2 and 128
1905 	 * Multiple of 2, rounded up
1906 	 */
1907 	clk_div = 2 * DIV_ROUND_UP(emi_freq, 2 * spi_freq);
1908 	if (clk_div < 2)
1909 		clk_div = 2;
1910 	else if (clk_div > 128)
1911 		clk_div = 128;
1912 
1913 	/*
1914 	 * Determine a suitable delay for the IP to complete a change of
1915 	 * direction of the FIFO. The required delay is related to the clock
1916 	 * divider used. The following heuristics are based on empirical tests,
1917 	 * using a 100MHz EMI clock.
1918 	 */
1919 	if (clk_div <= 4)
1920 		fsm->fifo_dir_delay = 0;
1921 	else if (clk_div <= 10)
1922 		fsm->fifo_dir_delay = 1;
1923 	else
1924 		fsm->fifo_dir_delay = DIV_ROUND_UP(clk_div, 10);
1925 
1926 	dev_dbg(fsm->dev, "emi_clk = %uHZ, spi_freq = %uHZ, clk_div = %u\n",
1927 		emi_freq, spi_freq, clk_div);
1928 
1929 	writel(clk_div, fsm->base + SPI_CLOCKDIV);
1930 }
1931 
1932 static int stfsm_init(struct stfsm *fsm)
1933 {
1934 	int ret;
1935 
1936 	/* Perform a soft reset of the FSM controller */
1937 	writel(SEQ_CFG_SWRESET, fsm->base + SPI_FAST_SEQ_CFG);
1938 	udelay(1);
1939 	writel(0, fsm->base + SPI_FAST_SEQ_CFG);
1940 
1941 	/* Set clock to 'safe' frequency initially */
1942 	stfsm_set_freq(fsm, STFSM_FLASH_SAFE_FREQ);
1943 
1944 	/* Switch to FSM */
1945 	ret = stfsm_set_mode(fsm, SPI_MODESELECT_FSM);
1946 	if (ret)
1947 		return ret;
1948 
1949 	/* Set timing parameters */
1950 	writel(SPI_CFG_DEVICE_ST            |
1951 	       SPI_CFG_DEFAULT_MIN_CS_HIGH  |
1952 	       SPI_CFG_DEFAULT_CS_SETUPHOLD |
1953 	       SPI_CFG_DEFAULT_DATA_HOLD,
1954 	       fsm->base + SPI_CONFIGDATA);
1955 	writel(STFSM_DEFAULT_WR_TIME, fsm->base + SPI_STATUS_WR_TIME_REG);
1956 
1957 	/*
1958 	 * Set the FSM 'WAIT' delay to the minimum workable value.  Note, for
1959 	 * our purposes, the WAIT instruction is used purely to achieve
1960 	 * "sequence validity" rather than actually implement a delay.
1961 	 */
1962 	writel(0x00000001, fsm->base + SPI_PROGRAM_ERASE_TIME);
1963 
1964 	/* Clear FIFO, just in case */
1965 	stfsm_clear_fifo(fsm);
1966 
1967 	return 0;
1968 }
1969 
1970 static void stfsm_fetch_platform_configs(struct platform_device *pdev)
1971 {
1972 	struct stfsm *fsm = platform_get_drvdata(pdev);
1973 	struct device_node *np = pdev->dev.of_node;
1974 	struct regmap *regmap;
1975 	uint32_t boot_device_reg;
1976 	uint32_t boot_device_spi;
1977 	uint32_t boot_device;     /* Value we read from *boot_device_reg */
1978 	int ret;
1979 
1980 	/* Booting from SPI NOR Flash is the default */
1981 	fsm->booted_from_spi = true;
1982 
1983 	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
1984 	if (IS_ERR(regmap))
1985 		goto boot_device_fail;
1986 
1987 	fsm->reset_signal = of_property_read_bool(np, "st,reset-signal");
1988 
1989 	fsm->reset_por = of_property_read_bool(np, "st,reset-por");
1990 
1991 	/* Where in the syscon the boot device information lives */
1992 	ret = of_property_read_u32(np, "st,boot-device-reg", &boot_device_reg);
1993 	if (ret)
1994 		goto boot_device_fail;
1995 
1996 	/* Boot device value when booted from SPI NOR */
1997 	ret = of_property_read_u32(np, "st,boot-device-spi", &boot_device_spi);
1998 	if (ret)
1999 		goto boot_device_fail;
2000 
2001 	ret = regmap_read(regmap, boot_device_reg, &boot_device);
2002 	if (ret)
2003 		goto boot_device_fail;
2004 
2005 	if (boot_device != boot_device_spi)
2006 		fsm->booted_from_spi = false;
2007 
2008 	return;
2009 
2010 boot_device_fail:
2011 	dev_warn(&pdev->dev,
2012 		 "failed to fetch boot device, assuming boot from SPI\n");
2013 }
2014 
2015 static int stfsm_probe(struct platform_device *pdev)
2016 {
2017 	struct device_node *np = pdev->dev.of_node;
2018 	struct flash_info *info;
2019 	struct resource *res;
2020 	struct stfsm *fsm;
2021 	int ret;
2022 
2023 	if (!np) {
2024 		dev_err(&pdev->dev, "No DT found\n");
2025 		return -EINVAL;
2026 	}
2027 
2028 	fsm = devm_kzalloc(&pdev->dev, sizeof(*fsm), GFP_KERNEL);
2029 	if (!fsm)
2030 		return -ENOMEM;
2031 
2032 	fsm->dev = &pdev->dev;
2033 
2034 	platform_set_drvdata(pdev, fsm);
2035 
2036 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2037 	if (!res) {
2038 		dev_err(&pdev->dev, "Resource not found\n");
2039 		return -ENODEV;
2040 	}
2041 
2042 	fsm->base = devm_ioremap_resource(&pdev->dev, res);
2043 	if (IS_ERR(fsm->base)) {
2044 		dev_err(&pdev->dev,
2045 			"Failed to reserve memory region %pR\n", res);
2046 		return PTR_ERR(fsm->base);
2047 	}
2048 
2049 	fsm->clk = devm_clk_get(&pdev->dev, NULL);
2050 	if (IS_ERR(fsm->clk)) {
2051 		dev_err(fsm->dev, "Couldn't find EMI clock.\n");
2052 		return PTR_ERR(fsm->clk);
2053 	}
2054 
2055 	ret = clk_prepare_enable(fsm->clk);
2056 	if (ret) {
2057 		dev_err(fsm->dev, "Failed to enable EMI clock.\n");
2058 		return ret;
2059 	}
2060 
2061 	mutex_init(&fsm->lock);
2062 
2063 	ret = stfsm_init(fsm);
2064 	if (ret) {
2065 		dev_err(&pdev->dev, "Failed to initialise FSM Controller\n");
2066 		goto err_clk_unprepare;
2067 	}
2068 
2069 	stfsm_fetch_platform_configs(pdev);
2070 
2071 	/* Detect SPI FLASH device */
2072 	info = stfsm_jedec_probe(fsm);
2073 	if (!info) {
2074 		ret = -ENODEV;
2075 		goto err_clk_unprepare;
2076 	}
2077 	fsm->info = info;
2078 
2079 	/* Use device size to determine address width */
2080 	if (info->sector_size * info->n_sectors > 0x1000000)
2081 		info->flags |= FLASH_FLAG_32BIT_ADDR;
2082 
2083 	/*
2084 	 * Configure READ/WRITE/ERASE sequences according to platform and
2085 	 * device flags.
2086 	 */
2087 	if (info->config)
2088 		ret = info->config(fsm);
2089 	else
2090 		ret = stfsm_prepare_rwe_seqs_default(fsm);
2091 	if (ret)
2092 		goto err_clk_unprepare;
2093 
2094 	fsm->mtd.name		= info->name;
2095 	fsm->mtd.dev.parent	= &pdev->dev;
2096 	mtd_set_of_node(&fsm->mtd, np);
2097 	fsm->mtd.type		= MTD_NORFLASH;
2098 	fsm->mtd.writesize	= 4;
2099 	fsm->mtd.writebufsize	= fsm->mtd.writesize;
2100 	fsm->mtd.flags		= MTD_CAP_NORFLASH;
2101 	fsm->mtd.size		= info->sector_size * info->n_sectors;
2102 	fsm->mtd.erasesize	= info->sector_size;
2103 
2104 	fsm->mtd._read  = stfsm_mtd_read;
2105 	fsm->mtd._write = stfsm_mtd_write;
2106 	fsm->mtd._erase = stfsm_mtd_erase;
2107 
2108 	dev_info(&pdev->dev,
2109 		"Found serial flash device: %s\n"
2110 		" size = %llx (%lldMiB) erasesize = 0x%08x (%uKiB)\n",
2111 		info->name,
2112 		(long long)fsm->mtd.size, (long long)(fsm->mtd.size >> 20),
2113 		fsm->mtd.erasesize, (fsm->mtd.erasesize >> 10));
2114 
2115 	ret = mtd_device_register(&fsm->mtd, NULL, 0);
2116 	if (ret) {
2117 err_clk_unprepare:
2118 		clk_disable_unprepare(fsm->clk);
2119 	}
2120 
2121 	return ret;
2122 }
2123 
2124 static int stfsm_remove(struct platform_device *pdev)
2125 {
2126 	struct stfsm *fsm = platform_get_drvdata(pdev);
2127 
2128 	WARN_ON(mtd_device_unregister(&fsm->mtd));
2129 
2130 	clk_disable_unprepare(fsm->clk);
2131 
2132 	return 0;
2133 }
2134 
2135 #ifdef CONFIG_PM_SLEEP
2136 static int stfsmfsm_suspend(struct device *dev)
2137 {
2138 	struct stfsm *fsm = dev_get_drvdata(dev);
2139 
2140 	clk_disable_unprepare(fsm->clk);
2141 
2142 	return 0;
2143 }
2144 
2145 static int stfsmfsm_resume(struct device *dev)
2146 {
2147 	struct stfsm *fsm = dev_get_drvdata(dev);
2148 
2149 	return clk_prepare_enable(fsm->clk);
2150 }
2151 #endif
2152 
2153 static SIMPLE_DEV_PM_OPS(stfsm_pm_ops, stfsmfsm_suspend, stfsmfsm_resume);
2154 
2155 static const struct of_device_id stfsm_match[] = {
2156 	{ .compatible = "st,spi-fsm", },
2157 	{},
2158 };
2159 MODULE_DEVICE_TABLE(of, stfsm_match);
2160 
2161 static struct platform_driver stfsm_driver = {
2162 	.probe		= stfsm_probe,
2163 	.remove		= stfsm_remove,
2164 	.driver		= {
2165 		.name	= "st-spi-fsm",
2166 		.of_match_table = stfsm_match,
2167 		.pm     = &stfsm_pm_ops,
2168 	},
2169 };
2170 module_platform_driver(stfsm_driver);
2171 
2172 MODULE_AUTHOR("Angus Clark <angus.clark@st.com>");
2173 MODULE_DESCRIPTION("ST SPI FSM driver");
2174 MODULE_LICENSE("GPL");
2175