2 * st_spi_fsm.c - ST Fast Sequence Mode (FSM) Serial Flash Controller
4 * Author: Angus Clark <angus.clark@st.com>
6 * Copyright (C) 2010-2014 STicroelectronics Limited
8 * JEDEC probe based on drivers/mtd/devices/m25p80.c
10 * This code is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/mtd/mtd.h>
19 #include <linux/sched.h>
20 #include <linux/delay.h>
24 #include "serial_flash_cmds.h"
27 * FSM SPI Controller Registers
29 #define SPI_CLOCKDIV 0x0010
30 #define SPI_MODESELECT 0x0018
31 #define SPI_CONFIGDATA 0x0020
32 #define SPI_STA_MODE_CHANGE 0x0028
33 #define SPI_FAST_SEQ_TRANSFER_SIZE 0x0100
34 #define SPI_FAST_SEQ_ADD1 0x0104
35 #define SPI_FAST_SEQ_ADD2 0x0108
36 #define SPI_FAST_SEQ_ADD_CFG 0x010c
37 #define SPI_FAST_SEQ_OPC1 0x0110
38 #define SPI_FAST_SEQ_OPC2 0x0114
39 #define SPI_FAST_SEQ_OPC3 0x0118
40 #define SPI_FAST_SEQ_OPC4 0x011c
41 #define SPI_FAST_SEQ_OPC5 0x0120
42 #define SPI_MODE_BITS 0x0124
43 #define SPI_DUMMY_BITS 0x0128
44 #define SPI_FAST_SEQ_FLASH_STA_DATA 0x012c
45 #define SPI_FAST_SEQ_1 0x0130
46 #define SPI_FAST_SEQ_2 0x0134
47 #define SPI_FAST_SEQ_3 0x0138
48 #define SPI_FAST_SEQ_4 0x013c
49 #define SPI_FAST_SEQ_CFG 0x0140
50 #define SPI_FAST_SEQ_STA 0x0144
51 #define SPI_QUAD_BOOT_SEQ_INIT_1 0x0148
52 #define SPI_QUAD_BOOT_SEQ_INIT_2 0x014c
53 #define SPI_QUAD_BOOT_READ_SEQ_1 0x0150
54 #define SPI_QUAD_BOOT_READ_SEQ_2 0x0154
55 #define SPI_PROGRAM_ERASE_TIME 0x0158
56 #define SPI_MULT_PAGE_REPEAT_SEQ_1 0x015c
57 #define SPI_MULT_PAGE_REPEAT_SEQ_2 0x0160
58 #define SPI_STATUS_WR_TIME_REG 0x0164
59 #define SPI_FAST_SEQ_DATA_REG 0x0300
62 * Register: SPI_MODESELECT
64 #define SPI_MODESELECT_CONTIG 0x01
65 #define SPI_MODESELECT_FASTREAD 0x02
66 #define SPI_MODESELECT_DUALIO 0x04
67 #define SPI_MODESELECT_FSM 0x08
68 #define SPI_MODESELECT_QUADBOOT 0x10
71 * Register: SPI_CONFIGDATA
73 #define SPI_CFG_DEVICE_ST 0x1
74 #define SPI_CFG_DEVICE_ATMEL 0x4
75 #define SPI_CFG_MIN_CS_HIGH(x) (((x) & 0xfff) << 4)
76 #define SPI_CFG_CS_SETUPHOLD(x) (((x) & 0xff) << 16)
77 #define SPI_CFG_DATA_HOLD(x) (((x) & 0xff) << 24)
79 #define SPI_CFG_DEFAULT_MIN_CS_HIGH SPI_CFG_MIN_CS_HIGH(0x0AA)
80 #define SPI_CFG_DEFAULT_CS_SETUPHOLD SPI_CFG_CS_SETUPHOLD(0xA0)
81 #define SPI_CFG_DEFAULT_DATA_HOLD SPI_CFG_DATA_HOLD(0x00)
84 * Register: SPI_FAST_SEQ_TRANSFER_SIZE
86 #define TRANSFER_SIZE(x) ((x) * 8)
89 * Register: SPI_FAST_SEQ_ADD_CFG
91 #define ADR_CFG_CYCLES_ADD1(x) ((x) << 0)
92 #define ADR_CFG_PADS_1_ADD1 (0x0 << 6)
93 #define ADR_CFG_PADS_2_ADD1 (0x1 << 6)
94 #define ADR_CFG_PADS_4_ADD1 (0x3 << 6)
95 #define ADR_CFG_CSDEASSERT_ADD1 (1 << 8)
96 #define ADR_CFG_CYCLES_ADD2(x) ((x) << (0+16))
97 #define ADR_CFG_PADS_1_ADD2 (0x0 << (6+16))
98 #define ADR_CFG_PADS_2_ADD2 (0x1 << (6+16))
99 #define ADR_CFG_PADS_4_ADD2 (0x3 << (6+16))
100 #define ADR_CFG_CSDEASSERT_ADD2 (1 << (8+16))
103 * Register: SPI_FAST_SEQ_n
105 #define SEQ_OPC_OPCODE(x) ((x) << 0)
106 #define SEQ_OPC_CYCLES(x) ((x) << 8)
107 #define SEQ_OPC_PADS_1 (0x0 << 14)
108 #define SEQ_OPC_PADS_2 (0x1 << 14)
109 #define SEQ_OPC_PADS_4 (0x3 << 14)
110 #define SEQ_OPC_CSDEASSERT (1 << 16)
113 * Register: SPI_FAST_SEQ_CFG
115 #define SEQ_CFG_STARTSEQ (1 << 0)
116 #define SEQ_CFG_SWRESET (1 << 5)
117 #define SEQ_CFG_CSDEASSERT (1 << 6)
118 #define SEQ_CFG_READNOTWRITE (1 << 7)
119 #define SEQ_CFG_ERASE (1 << 8)
120 #define SEQ_CFG_PADS_1 (0x0 << 16)
121 #define SEQ_CFG_PADS_2 (0x1 << 16)
122 #define SEQ_CFG_PADS_4 (0x3 << 16)
125 * Register: SPI_MODE_BITS
127 #define MODE_DATA(x) (x & 0xff)
128 #define MODE_CYCLES(x) ((x & 0x3f) << 16)
129 #define MODE_PADS_1 (0x0 << 22)
130 #define MODE_PADS_2 (0x1 << 22)
131 #define MODE_PADS_4 (0x3 << 22)
132 #define DUMMY_CSDEASSERT (1 << 24)
135 * Register: SPI_DUMMY_BITS
137 #define DUMMY_CYCLES(x) ((x & 0x3f) << 16)
138 #define DUMMY_PADS_1 (0x0 << 22)
139 #define DUMMY_PADS_2 (0x1 << 22)
140 #define DUMMY_PADS_4 (0x3 << 22)
141 #define DUMMY_CSDEASSERT (1 << 24)
144 * Register: SPI_FAST_SEQ_FLASH_STA_DATA
146 #define STA_DATA_BYTE1(x) ((x & 0xff) << 0)
147 #define STA_DATA_BYTE2(x) ((x & 0xff) << 8)
148 #define STA_PADS_1 (0x0 << 16)
149 #define STA_PADS_2 (0x1 << 16)
150 #define STA_PADS_4 (0x3 << 16)
151 #define STA_CSDEASSERT (0x1 << 20)
152 #define STA_RDNOTWR (0x1 << 21)
155 * FSM SPI Instruction Opcodes
157 #define STFSM_OPC_CMD 0x1
158 #define STFSM_OPC_ADD 0x2
159 #define STFSM_OPC_STA 0x3
160 #define STFSM_OPC_MODE 0x4
161 #define STFSM_OPC_DUMMY 0x5
162 #define STFSM_OPC_DATA 0x6
163 #define STFSM_OPC_WAIT 0x7
164 #define STFSM_OPC_JUMP 0x8
165 #define STFSM_OPC_GOTO 0x9
166 #define STFSM_OPC_STOP 0xF
169 * FSM SPI Instructions (== opcode + operand).
171 #define STFSM_INSTR(cmd, op) ((cmd) | ((op) << 4))
173 #define STFSM_INST_CMD1 STFSM_INSTR(STFSM_OPC_CMD, 1)
174 #define STFSM_INST_CMD2 STFSM_INSTR(STFSM_OPC_CMD, 2)
175 #define STFSM_INST_CMD3 STFSM_INSTR(STFSM_OPC_CMD, 3)
176 #define STFSM_INST_CMD4 STFSM_INSTR(STFSM_OPC_CMD, 4)
177 #define STFSM_INST_CMD5 STFSM_INSTR(STFSM_OPC_CMD, 5)
178 #define STFSM_INST_ADD1 STFSM_INSTR(STFSM_OPC_ADD, 1)
179 #define STFSM_INST_ADD2 STFSM_INSTR(STFSM_OPC_ADD, 2)
181 #define STFSM_INST_DATA_WRITE STFSM_INSTR(STFSM_OPC_DATA, 1)
182 #define STFSM_INST_DATA_READ STFSM_INSTR(STFSM_OPC_DATA, 2)
184 #define STFSM_INST_STA_RD1 STFSM_INSTR(STFSM_OPC_STA, 0x1)
185 #define STFSM_INST_STA_WR1 STFSM_INSTR(STFSM_OPC_STA, 0x1)
186 #define STFSM_INST_STA_RD2 STFSM_INSTR(STFSM_OPC_STA, 0x2)
187 #define STFSM_INST_STA_WR1_2 STFSM_INSTR(STFSM_OPC_STA, 0x3)
189 #define STFSM_INST_MODE STFSM_INSTR(STFSM_OPC_MODE, 0)
190 #define STFSM_INST_DUMMY STFSM_INSTR(STFSM_OPC_DUMMY, 0)
191 #define STFSM_INST_WAIT STFSM_INSTR(STFSM_OPC_WAIT, 0)
192 #define STFSM_INST_STOP STFSM_INSTR(STFSM_OPC_STOP, 0)
194 #define STFSM_DEFAULT_EMI_FREQ 100000000UL /* 100 MHz */
195 #define STFSM_DEFAULT_WR_TIME (STFSM_DEFAULT_EMI_FREQ * (15/1000)) /* 15ms */
197 #define STFSM_FLASH_SAFE_FREQ 10000000UL /* 10 MHz */
199 #define STFSM_MAX_WAIT_SEQ_MS 1000 /* FSM execution time */
204 struct resource *region;
208 uint32_t fifo_dir_delay;
222 } __packed __aligned(4);
224 static struct stfsm_seq stfsm_seq_read_jedec = {
225 .data_size = TRANSFER_SIZE(8),
226 .seq_opc[0] = (SEQ_OPC_PADS_1 |
228 SEQ_OPC_OPCODE(FLASH_CMD_RDID)),
231 STFSM_INST_DATA_READ,
234 .seq_cfg = (SEQ_CFG_PADS_1 |
235 SEQ_CFG_READNOTWRITE |
240 static inline int stfsm_is_idle(struct stfsm *fsm)
242 return readl(fsm->base + SPI_FAST_SEQ_STA) & 0x10;
245 static inline uint32_t stfsm_fifo_available(struct stfsm *fsm)
247 return (readl(fsm->base + SPI_FAST_SEQ_STA) >> 5) & 0x7f;
250 static void stfsm_clear_fifo(struct stfsm *fsm)
255 avail = stfsm_fifo_available(fsm);
260 readl(fsm->base + SPI_FAST_SEQ_DATA_REG);
266 static inline void stfsm_load_seq(struct stfsm *fsm,
267 const struct stfsm_seq *seq)
269 void __iomem *dst = fsm->base + SPI_FAST_SEQ_TRANSFER_SIZE;
270 const uint32_t *src = (const uint32_t *)seq;
271 int words = sizeof(*seq) / sizeof(*src);
273 BUG_ON(!stfsm_is_idle(fsm));
282 static void stfsm_wait_seq(struct stfsm *fsm)
284 unsigned long deadline;
287 deadline = jiffies + msecs_to_jiffies(STFSM_MAX_WAIT_SEQ_MS);
290 if (time_after_eq(jiffies, deadline))
293 if (stfsm_is_idle(fsm))
299 dev_err(fsm->dev, "timeout on sequence completion\n");
302 static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf,
305 uint32_t remaining = size >> 2;
309 dev_dbg(fsm->dev, "Reading %d bytes from FIFO\n", size);
311 BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
315 avail = stfsm_fifo_available(fsm);
320 words = min(avail, remaining);
323 readsl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
328 static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *const jedec)
330 const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
333 stfsm_load_seq(fsm, seq);
335 stfsm_read_fifo(fsm, tmp, 8);
337 memcpy(jedec, tmp, 5);
342 static struct flash_info *stfsm_jedec_probe(struct stfsm *fsm)
348 stfsm_read_jedec(fsm, id);
350 jedec = id[0] << 16 | id[1] << 8 | id[2];
352 * JEDEC also defines an optional "extended device information"
353 * string for after vendor-specific data, after the three bytes
354 * we use here. Supporting some chips might require using it.
356 ext_jedec = id[3] << 8 | id[4];
358 dev_dbg(fsm->dev, "JEDEC = 0x%08x [%02x %02x %02x %02x %02x]\n",
359 jedec, id[0], id[1], id[2], id[3], id[4]);
364 static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode)
366 int ret, timeout = 10;
368 /* Wait for controller to accept mode change */
370 ret = readl(fsm->base + SPI_STA_MODE_CHANGE);
379 writel(mode, fsm->base + SPI_MODESELECT);
384 static void stfsm_set_freq(struct stfsm *fsm, uint32_t spi_freq)
389 /* TODO: Make this dynamic */
390 emi_freq = STFSM_DEFAULT_EMI_FREQ;
393 * Calculate clk_div - values between 2 and 128
394 * Multiple of 2, rounded up
396 clk_div = 2 * DIV_ROUND_UP(emi_freq, 2 * spi_freq);
399 else if (clk_div > 128)
403 * Determine a suitable delay for the IP to complete a change of
404 * direction of the FIFO. The required delay is related to the clock
405 * divider used. The following heuristics are based on empirical tests,
406 * using a 100MHz EMI clock.
409 fsm->fifo_dir_delay = 0;
410 else if (clk_div <= 10)
411 fsm->fifo_dir_delay = 1;
413 fsm->fifo_dir_delay = DIV_ROUND_UP(clk_div, 10);
415 dev_dbg(fsm->dev, "emi_clk = %uHZ, spi_freq = %uHZ, clk_div = %u\n",
416 emi_freq, spi_freq, clk_div);
418 writel(clk_div, fsm->base + SPI_CLOCKDIV);
421 static int stfsm_init(struct stfsm *fsm)
425 /* Perform a soft reset of the FSM controller */
426 writel(SEQ_CFG_SWRESET, fsm->base + SPI_FAST_SEQ_CFG);
428 writel(0, fsm->base + SPI_FAST_SEQ_CFG);
430 /* Set clock to 'safe' frequency initially */
431 stfsm_set_freq(fsm, STFSM_FLASH_SAFE_FREQ);
434 ret = stfsm_set_mode(fsm, SPI_MODESELECT_FSM);
438 /* Set timing parameters */
439 writel(SPI_CFG_DEVICE_ST |
440 SPI_CFG_DEFAULT_MIN_CS_HIGH |
441 SPI_CFG_DEFAULT_CS_SETUPHOLD |
442 SPI_CFG_DEFAULT_DATA_HOLD,
443 fsm->base + SPI_CONFIGDATA);
444 writel(STFSM_DEFAULT_WR_TIME, fsm->base + SPI_STATUS_WR_TIME_REG);
446 /* Clear FIFO, just in case */
447 stfsm_clear_fifo(fsm);
452 static int stfsm_probe(struct platform_device *pdev)
454 struct device_node *np = pdev->dev.of_node;
455 struct resource *res;
460 dev_err(&pdev->dev, "No DT found\n");
464 fsm = devm_kzalloc(&pdev->dev, sizeof(*fsm), GFP_KERNEL);
468 fsm->dev = &pdev->dev;
470 platform_set_drvdata(pdev, fsm);
472 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
474 dev_err(&pdev->dev, "Resource not found\n");
478 fsm->base = devm_ioremap_resource(&pdev->dev, res);
479 if (IS_ERR(fsm->base)) {
481 "Failed to reserve memory region %pR\n", res);
482 return PTR_ERR(fsm->base);
485 mutex_init(&fsm->lock);
487 ret = stfsm_init(fsm);
489 dev_err(&pdev->dev, "Failed to initialise FSM Controller\n");
493 /* Detect SPI FLASH device */
494 stfsm_jedec_probe(fsm);
496 fsm->mtd.dev.parent = &pdev->dev;
497 fsm->mtd.type = MTD_NORFLASH;
498 fsm->mtd.writesize = 4;
499 fsm->mtd.writebufsize = fsm->mtd.writesize;
500 fsm->mtd.flags = MTD_CAP_NORFLASH;
502 return mtd_device_parse_register(&fsm->mtd, NULL, NULL, NULL, 0);
505 static int stfsm_remove(struct platform_device *pdev)
507 struct stfsm *fsm = platform_get_drvdata(pdev);
510 err = mtd_device_unregister(&fsm->mtd);
517 static struct of_device_id stfsm_match[] = {
518 { .compatible = "st,spi-fsm", },
521 MODULE_DEVICE_TABLE(of, stfsm_match);
523 static struct platform_driver stfsm_driver = {
524 .probe = stfsm_probe,
525 .remove = stfsm_remove,
527 .name = "st-spi-fsm",
528 .owner = THIS_MODULE,
529 .of_match_table = stfsm_match,
532 module_platform_driver(stfsm_driver);
534 MODULE_AUTHOR("Angus Clark <angus.clark@st.com>");
535 MODULE_DESCRIPTION("ST SPI FSM driver");
536 MODULE_LICENSE("GPL");