/* * st_spi_fsm.c - ST Fast Sequence Mode (FSM) Serial Flash Controller * * Author: Angus Clark * * Copyright (C) 2010-2014 STicroelectronics Limited * * JEDEC probe based on drivers/mtd/devices/m25p80.c * * This code is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include #include #include #include #include #include #include #include /* * FSM SPI Controller Registers */ #define SPI_CLOCKDIV 0x0010 #define SPI_MODESELECT 0x0018 #define SPI_CONFIGDATA 0x0020 #define SPI_STA_MODE_CHANGE 0x0028 #define SPI_FAST_SEQ_TRANSFER_SIZE 0x0100 #define SPI_FAST_SEQ_ADD1 0x0104 #define SPI_FAST_SEQ_ADD2 0x0108 #define SPI_FAST_SEQ_ADD_CFG 0x010c #define SPI_FAST_SEQ_OPC1 0x0110 #define SPI_FAST_SEQ_OPC2 0x0114 #define SPI_FAST_SEQ_OPC3 0x0118 #define SPI_FAST_SEQ_OPC4 0x011c #define SPI_FAST_SEQ_OPC5 0x0120 #define SPI_MODE_BITS 0x0124 #define SPI_DUMMY_BITS 0x0128 #define SPI_FAST_SEQ_FLASH_STA_DATA 0x012c #define SPI_FAST_SEQ_1 0x0130 #define SPI_FAST_SEQ_2 0x0134 #define SPI_FAST_SEQ_3 0x0138 #define SPI_FAST_SEQ_4 0x013c #define SPI_FAST_SEQ_CFG 0x0140 #define SPI_FAST_SEQ_STA 0x0144 #define SPI_QUAD_BOOT_SEQ_INIT_1 0x0148 #define SPI_QUAD_BOOT_SEQ_INIT_2 0x014c #define SPI_QUAD_BOOT_READ_SEQ_1 0x0150 #define SPI_QUAD_BOOT_READ_SEQ_2 0x0154 #define SPI_PROGRAM_ERASE_TIME 0x0158 #define SPI_MULT_PAGE_REPEAT_SEQ_1 0x015c #define SPI_MULT_PAGE_REPEAT_SEQ_2 0x0160 #define SPI_STATUS_WR_TIME_REG 0x0164 #define SPI_FAST_SEQ_DATA_REG 0x0300 /* * Register: SPI_MODESELECT */ #define SPI_MODESELECT_CONTIG 0x01 #define SPI_MODESELECT_FASTREAD 0x02 #define SPI_MODESELECT_DUALIO 0x04 #define SPI_MODESELECT_FSM 0x08 #define SPI_MODESELECT_QUADBOOT 0x10 /* * Register: SPI_CONFIGDATA */ #define SPI_CFG_DEVICE_ST 0x1 #define SPI_CFG_DEVICE_ATMEL 0x4 #define SPI_CFG_MIN_CS_HIGH(x) (((x) & 0xfff) << 4) #define SPI_CFG_CS_SETUPHOLD(x) (((x) & 0xff) << 16) #define SPI_CFG_DATA_HOLD(x) (((x) & 0xff) << 24) #define SPI_CFG_DEFAULT_MIN_CS_HIGH SPI_CFG_MIN_CS_HIGH(0x0AA) #define SPI_CFG_DEFAULT_CS_SETUPHOLD SPI_CFG_CS_SETUPHOLD(0xA0) #define SPI_CFG_DEFAULT_DATA_HOLD SPI_CFG_DATA_HOLD(0x00) /* * Register: SPI_FAST_SEQ_TRANSFER_SIZE */ #define TRANSFER_SIZE(x) ((x) * 8) /* * Register: SPI_FAST_SEQ_ADD_CFG */ #define ADR_CFG_CYCLES_ADD1(x) ((x) << 0) #define ADR_CFG_PADS_1_ADD1 (0x0 << 6) #define ADR_CFG_PADS_2_ADD1 (0x1 << 6) #define ADR_CFG_PADS_4_ADD1 (0x3 << 6) #define ADR_CFG_CSDEASSERT_ADD1 (1 << 8) #define ADR_CFG_CYCLES_ADD2(x) ((x) << (0+16)) #define ADR_CFG_PADS_1_ADD2 (0x0 << (6+16)) #define ADR_CFG_PADS_2_ADD2 (0x1 << (6+16)) #define ADR_CFG_PADS_4_ADD2 (0x3 << (6+16)) #define ADR_CFG_CSDEASSERT_ADD2 (1 << (8+16)) /* * Register: SPI_FAST_SEQ_n */ #define SEQ_OPC_OPCODE(x) ((x) << 0) #define SEQ_OPC_CYCLES(x) ((x) << 8) #define SEQ_OPC_PADS_1 (0x0 << 14) #define SEQ_OPC_PADS_2 (0x1 << 14) #define SEQ_OPC_PADS_4 (0x3 << 14) #define SEQ_OPC_CSDEASSERT (1 << 16) /* * Register: SPI_FAST_SEQ_CFG */ #define SEQ_CFG_STARTSEQ (1 << 0) #define SEQ_CFG_SWRESET (1 << 5) #define SEQ_CFG_CSDEASSERT (1 << 6) #define SEQ_CFG_READNOTWRITE (1 << 7) #define SEQ_CFG_ERASE (1 << 8) #define SEQ_CFG_PADS_1 (0x0 << 16) #define SEQ_CFG_PADS_2 (0x1 << 16) #define SEQ_CFG_PADS_4 (0x3 << 16) /* * Register: SPI_MODE_BITS */ #define MODE_DATA(x) (x & 0xff) #define MODE_CYCLES(x) ((x & 0x3f) << 16) #define MODE_PADS_1 (0x0 << 22) #define MODE_PADS_2 (0x1 << 22) #define MODE_PADS_4 (0x3 << 22) #define DUMMY_CSDEASSERT (1 << 24) /* * Register: SPI_DUMMY_BITS */ #define DUMMY_CYCLES(x) ((x & 0x3f) << 16) #define DUMMY_PADS_1 (0x0 << 22) #define DUMMY_PADS_2 (0x1 << 22) #define DUMMY_PADS_4 (0x3 << 22) #define DUMMY_CSDEASSERT (1 << 24) /* * Register: SPI_FAST_SEQ_FLASH_STA_DATA */ #define STA_DATA_BYTE1(x) ((x & 0xff) << 0) #define STA_DATA_BYTE2(x) ((x & 0xff) << 8) #define STA_PADS_1 (0x0 << 16) #define STA_PADS_2 (0x1 << 16) #define STA_PADS_4 (0x3 << 16) #define STA_CSDEASSERT (0x1 << 20) #define STA_RDNOTWR (0x1 << 21) /* * FSM SPI Instruction Opcodes */ #define STFSM_OPC_CMD 0x1 #define STFSM_OPC_ADD 0x2 #define STFSM_OPC_STA 0x3 #define STFSM_OPC_MODE 0x4 #define STFSM_OPC_DUMMY 0x5 #define STFSM_OPC_DATA 0x6 #define STFSM_OPC_WAIT 0x7 #define STFSM_OPC_JUMP 0x8 #define STFSM_OPC_GOTO 0x9 #define STFSM_OPC_STOP 0xF /* * FSM SPI Instructions (== opcode + operand). */ #define STFSM_INSTR(cmd, op) ((cmd) | ((op) << 4)) #define STFSM_INST_CMD1 STFSM_INSTR(STFSM_OPC_CMD, 1) #define STFSM_INST_CMD2 STFSM_INSTR(STFSM_OPC_CMD, 2) #define STFSM_INST_CMD3 STFSM_INSTR(STFSM_OPC_CMD, 3) #define STFSM_INST_CMD4 STFSM_INSTR(STFSM_OPC_CMD, 4) #define STFSM_INST_CMD5 STFSM_INSTR(STFSM_OPC_CMD, 5) #define STFSM_INST_ADD1 STFSM_INSTR(STFSM_OPC_ADD, 1) #define STFSM_INST_ADD2 STFSM_INSTR(STFSM_OPC_ADD, 2) #define STFSM_INST_DATA_WRITE STFSM_INSTR(STFSM_OPC_DATA, 1) #define STFSM_INST_DATA_READ STFSM_INSTR(STFSM_OPC_DATA, 2) #define STFSM_INST_STA_RD1 STFSM_INSTR(STFSM_OPC_STA, 0x1) #define STFSM_INST_STA_WR1 STFSM_INSTR(STFSM_OPC_STA, 0x1) #define STFSM_INST_STA_RD2 STFSM_INSTR(STFSM_OPC_STA, 0x2) #define STFSM_INST_STA_WR1_2 STFSM_INSTR(STFSM_OPC_STA, 0x3) #define STFSM_INST_MODE STFSM_INSTR(STFSM_OPC_MODE, 0) #define STFSM_INST_DUMMY STFSM_INSTR(STFSM_OPC_DUMMY, 0) #define STFSM_INST_WAIT STFSM_INSTR(STFSM_OPC_WAIT, 0) #define STFSM_INST_STOP STFSM_INSTR(STFSM_OPC_STOP, 0) #define STFSM_DEFAULT_EMI_FREQ 100000000UL /* 100 MHz */ #define STFSM_DEFAULT_WR_TIME (STFSM_DEFAULT_EMI_FREQ * (15/1000)) /* 15ms */ #define STFSM_FLASH_SAFE_FREQ 10000000UL /* 10 MHz */ #define STFSM_MAX_WAIT_SEQ_MS 1000 /* FSM execution time */ struct stfsm { struct device *dev; void __iomem *base; struct resource *region; struct mtd_info mtd; struct mutex lock; uint32_t fifo_dir_delay; }; struct stfsm_seq { uint32_t data_size; uint32_t addr1; uint32_t addr2; uint32_t addr_cfg; uint32_t seq_opc[5]; uint32_t mode; uint32_t dummy; uint32_t status; uint8_t seq[16]; uint32_t seq_cfg; } __packed __aligned(4); static inline int stfsm_is_idle(struct stfsm *fsm) { return readl(fsm->base + SPI_FAST_SEQ_STA) & 0x10; } static inline uint32_t stfsm_fifo_available(struct stfsm *fsm) { return (readl(fsm->base + SPI_FAST_SEQ_STA) >> 5) & 0x7f; } static void stfsm_clear_fifo(struct stfsm *fsm) { uint32_t avail; for (;;) { avail = stfsm_fifo_available(fsm); if (!avail) break; while (avail) { readl(fsm->base + SPI_FAST_SEQ_DATA_REG); avail--; } } } static inline void stfsm_load_seq(struct stfsm *fsm, const struct stfsm_seq *seq) { void __iomem *dst = fsm->base + SPI_FAST_SEQ_TRANSFER_SIZE; const uint32_t *src = (const uint32_t *)seq; int words = sizeof(*seq) / sizeof(*src); BUG_ON(!stfsm_is_idle(fsm)); while (words--) { writel(*src, dst); src++; dst += 4; } } static void stfsm_wait_seq(struct stfsm *fsm) { unsigned long deadline; int timeout = 0; deadline = jiffies + msecs_to_jiffies(STFSM_MAX_WAIT_SEQ_MS); while (!timeout) { if (time_after_eq(jiffies, deadline)) timeout = 1; if (stfsm_is_idle(fsm)) return; cond_resched(); } dev_err(fsm->dev, "timeout on sequence completion\n"); } static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode) { int ret, timeout = 10; /* Wait for controller to accept mode change */ while (--timeout) { ret = readl(fsm->base + SPI_STA_MODE_CHANGE); if (ret & 0x1) break; udelay(1); } if (!timeout) return -EBUSY; writel(mode, fsm->base + SPI_MODESELECT); return 0; } static void stfsm_set_freq(struct stfsm *fsm, uint32_t spi_freq) { uint32_t emi_freq; uint32_t clk_div; /* TODO: Make this dynamic */ emi_freq = STFSM_DEFAULT_EMI_FREQ; /* * Calculate clk_div - values between 2 and 128 * Multiple of 2, rounded up */ clk_div = 2 * DIV_ROUND_UP(emi_freq, 2 * spi_freq); if (clk_div < 2) clk_div = 2; else if (clk_div > 128) clk_div = 128; /* * Determine a suitable delay for the IP to complete a change of * direction of the FIFO. The required delay is related to the clock * divider used. The following heuristics are based on empirical tests, * using a 100MHz EMI clock. */ if (clk_div <= 4) fsm->fifo_dir_delay = 0; else if (clk_div <= 10) fsm->fifo_dir_delay = 1; else fsm->fifo_dir_delay = DIV_ROUND_UP(clk_div, 10); dev_dbg(fsm->dev, "emi_clk = %uHZ, spi_freq = %uHZ, clk_div = %u\n", emi_freq, spi_freq, clk_div); writel(clk_div, fsm->base + SPI_CLOCKDIV); } static int stfsm_init(struct stfsm *fsm) { int ret; /* Perform a soft reset of the FSM controller */ writel(SEQ_CFG_SWRESET, fsm->base + SPI_FAST_SEQ_CFG); udelay(1); writel(0, fsm->base + SPI_FAST_SEQ_CFG); /* Set clock to 'safe' frequency initially */ stfsm_set_freq(fsm, STFSM_FLASH_SAFE_FREQ); /* Switch to FSM */ ret = stfsm_set_mode(fsm, SPI_MODESELECT_FSM); if (ret) return ret; /* Set timing parameters */ writel(SPI_CFG_DEVICE_ST | SPI_CFG_DEFAULT_MIN_CS_HIGH | SPI_CFG_DEFAULT_CS_SETUPHOLD | SPI_CFG_DEFAULT_DATA_HOLD, fsm->base + SPI_CONFIGDATA); writel(STFSM_DEFAULT_WR_TIME, fsm->base + SPI_STATUS_WR_TIME_REG); /* Clear FIFO, just in case */ stfsm_clear_fifo(fsm); return 0; } static int stfsm_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct resource *res; struct stfsm *fsm; int ret; if (!np) { dev_err(&pdev->dev, "No DT found\n"); return -EINVAL; } fsm = devm_kzalloc(&pdev->dev, sizeof(*fsm), GFP_KERNEL); if (!fsm) return -ENOMEM; fsm->dev = &pdev->dev; platform_set_drvdata(pdev, fsm); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "Resource not found\n"); return -ENODEV; } fsm->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(fsm->base)) { dev_err(&pdev->dev, "Failed to reserve memory region %pR\n", res); return PTR_ERR(fsm->base); } mutex_init(&fsm->lock); ret = stfsm_init(fsm); if (ret) { dev_err(&pdev->dev, "Failed to initialise FSM Controller\n"); return ret; } fsm->mtd.dev.parent = &pdev->dev; fsm->mtd.type = MTD_NORFLASH; fsm->mtd.writesize = 4; fsm->mtd.writebufsize = fsm->mtd.writesize; fsm->mtd.flags = MTD_CAP_NORFLASH; return mtd_device_parse_register(&fsm->mtd, NULL, NULL, NULL, 0); } static int stfsm_remove(struct platform_device *pdev) { struct stfsm *fsm = platform_get_drvdata(pdev); int err; err = mtd_device_unregister(&fsm->mtd); if (err) return err; return 0; } static struct of_device_id stfsm_match[] = { { .compatible = "st,spi-fsm", }, {}, }; MODULE_DEVICE_TABLE(of, stfsm_match); static struct platform_driver stfsm_driver = { .probe = stfsm_probe, .remove = stfsm_remove, .driver = { .name = "st-spi-fsm", .owner = THIS_MODULE, .of_match_table = stfsm_match, }, }; module_platform_driver(stfsm_driver); MODULE_AUTHOR("Angus Clark "); MODULE_DESCRIPTION("ST SPI FSM driver"); MODULE_LICENSE("GPL");