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linux-stable/drivers/mtd/devices/st_spi_fsm.c
Lee Jones 0de08e43cd mtd: st_spi_fsm: Provide a method to put the chip into 32bit addressing mode 
Most Serial Flash chips support 24bit addressing as a default but more
recent incarnations can support 32bit. Based on information provided
though platform specific data and capabilities we can determine whether
or not our current chip can. This patch provides a means to setup the
FSM message sequence to put the chip into 32bit mode.

Acked-by Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-20 04:17:18 -07:00

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/*
* st_spi_fsm.c - ST Fast Sequence Mode (FSM) Serial Flash Controller
*
* Author: Angus Clark <angus.clark@st.com>
*
* 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 <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/platform_device.h>
#include <linux/mfd/syscon.h>
#include <linux/mtd/mtd.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of.h>
#include "serial_flash_cmds.h"
/*
* 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;
struct flash_info *info;
uint32_t fifo_dir_delay;
bool booted_from_spi;
bool reset_signal;
bool reset_por;
};
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);
/* Parameters to configure a READ or WRITE FSM sequence */
struct seq_rw_config {
uint32_t flags; /* flags to support config */
uint8_t cmd; /* FLASH command */
int write; /* Write Sequence */
uint8_t addr_pads; /* No. of addr pads (MODE & DUMMY) */
uint8_t data_pads; /* No. of data pads */
uint8_t mode_data; /* MODE data */
uint8_t mode_cycles; /* No. of MODE cycles */
uint8_t dummy_cycles; /* No. of DUMMY cycles */
};
/* SPI Flash Device Table */
struct flash_info {
char *name;
/*
* JEDEC id zero means "no ID" (most older chips); otherwise it has
* a high byte of zero plus three data bytes: the manufacturer id,
* then a two byte device id.
*/
u32 jedec_id;
u16 ext_id;
/*
* The size listed here is what works with FLASH_CMD_SE, which isn't
* necessarily called a "sector" by the vendor.
*/
unsigned sector_size;
u16 n_sectors;
u32 flags;
/*
* Note, where FAST_READ is supported, freq_max specifies the
* FAST_READ frequency, not the READ frequency.
*/
u32 max_freq;
int (*config)(struct stfsm *);
};
static struct flash_info flash_types[] = {
/*
* ST Microelectronics/Numonyx --
* (newer production versions may have feature updates
* (eg faster operating frequency)
*/
#define M25P_FLAG (FLASH_FLAG_READ_WRITE | FLASH_FLAG_READ_FAST)
{ "m25p40", 0x202013, 0, 64 * 1024, 8, M25P_FLAG, 25, NULL },
{ "m25p80", 0x202014, 0, 64 * 1024, 16, M25P_FLAG, 25, NULL },
{ "m25p16", 0x202015, 0, 64 * 1024, 32, M25P_FLAG, 25, NULL },
{ "m25p32", 0x202016, 0, 64 * 1024, 64, M25P_FLAG, 50, NULL },
{ "m25p64", 0x202017, 0, 64 * 1024, 128, M25P_FLAG, 50, NULL },
{ "m25p128", 0x202018, 0, 256 * 1024, 64, M25P_FLAG, 50, NULL },
#define M25PX_FLAG (FLASH_FLAG_READ_WRITE | \
FLASH_FLAG_READ_FAST | \
FLASH_FLAG_READ_1_1_2 | \
FLASH_FLAG_WRITE_1_1_2)
{ "m25px32", 0x207116, 0, 64 * 1024, 64, M25PX_FLAG, 75, NULL },
{ "m25px64", 0x207117, 0, 64 * 1024, 128, M25PX_FLAG, 75, NULL },
#define MX25_FLAG (FLASH_FLAG_READ_WRITE | \
FLASH_FLAG_READ_FAST | \
FLASH_FLAG_READ_1_1_2 | \
FLASH_FLAG_READ_1_2_2 | \
FLASH_FLAG_READ_1_1_4 | \
FLASH_FLAG_READ_1_4_4 | \
FLASH_FLAG_SE_4K | \
FLASH_FLAG_SE_32K)
{ "mx25l25635e", 0xc22019, 0, 64*1024, 512,
(MX25_FLAG | FLASH_FLAG_32BIT_ADDR | FLASH_FLAG_RESET), 70, NULL }
#define N25Q_FLAG (FLASH_FLAG_READ_WRITE | \
FLASH_FLAG_READ_FAST | \
FLASH_FLAG_READ_1_1_2 | \
FLASH_FLAG_READ_1_2_2 | \
FLASH_FLAG_READ_1_1_4 | \
FLASH_FLAG_READ_1_4_4 | \
FLASH_FLAG_WRITE_1_1_2 | \
FLASH_FLAG_WRITE_1_2_2 | \
FLASH_FLAG_WRITE_1_1_4 | \
FLASH_FLAG_WRITE_1_4_4)
{ "n25q128", 0x20ba18, 0, 64 * 1024, 256, N25Q_FLAG, 108, NULL },
{ "n25q256", 0x20ba19, 0, 64 * 1024, 512,
N25Q_FLAG | FLASH_FLAG_32BIT_ADDR, 108, NULL },
/*
* Spansion S25FLxxxP
* - 256KiB and 64KiB sector variants (identified by ext. JEDEC)
*/
#define S25FLXXXP_FLAG (FLASH_FLAG_READ_WRITE | \
FLASH_FLAG_READ_1_1_2 | \
FLASH_FLAG_READ_1_2_2 | \
FLASH_FLAG_READ_1_1_4 | \
FLASH_FLAG_READ_1_4_4 | \
FLASH_FLAG_WRITE_1_1_4 | \
FLASH_FLAG_READ_FAST)
{ "s25fl129p0", 0x012018, 0x4d00, 256 * 1024, 64, S25FLXXXP_FLAG, 80,
NULL },
{ "s25fl129p1", 0x012018, 0x4d01, 64 * 1024, 256, S25FLXXXP_FLAG, 80,
NULL },
/*
* Spansion S25FLxxxS
* - 256KiB and 64KiB sector variants (identified by ext. JEDEC)
* - RESET# signal supported by die but not bristled out on all
* package types. The package type is a function of board design,
* so this information is captured in the board's flags.
* - Supports 'DYB' sector protection. Depending on variant, sectors
* may default to locked state on power-on.
*/
#define S25FLXXXS_FLAG (S25FLXXXP_FLAG | \
FLASH_FLAG_RESET | \
FLASH_FLAG_DYB_LOCKING)
{ "s25fl128s0", 0x012018, 0x0300, 256 * 1024, 64, S25FLXXXS_FLAG, 80,
NULL },
{ "s25fl128s1", 0x012018, 0x0301, 64 * 1024, 256, S25FLXXXS_FLAG, 80,
NULL },
{ "s25fl256s0", 0x010219, 0x4d00, 256 * 1024, 128,
S25FLXXXS_FLAG | FLASH_FLAG_32BIT_ADDR, 80, NULL },
{ "s25fl256s1", 0x010219, 0x4d01, 64 * 1024, 512,
S25FLXXXS_FLAG | FLASH_FLAG_32BIT_ADDR, 80, NULL },
/* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
#define W25X_FLAG (FLASH_FLAG_READ_WRITE | \
FLASH_FLAG_READ_FAST | \
FLASH_FLAG_READ_1_1_2 | \
FLASH_FLAG_WRITE_1_1_2)
{ "w25x40", 0xef3013, 0, 64 * 1024, 8, W25X_FLAG, 75, NULL },
{ "w25x80", 0xef3014, 0, 64 * 1024, 16, W25X_FLAG, 75, NULL },
{ "w25x16", 0xef3015, 0, 64 * 1024, 32, W25X_FLAG, 75, NULL },
{ "w25x32", 0xef3016, 0, 64 * 1024, 64, W25X_FLAG, 75, NULL },
{ "w25x64", 0xef3017, 0, 64 * 1024, 128, W25X_FLAG, 75, NULL },
/* Winbond -- w25q "blocks" are 64K, "sectors" are 4KiB */
#define W25Q_FLAG (FLASH_FLAG_READ_WRITE | \
FLASH_FLAG_READ_FAST | \
FLASH_FLAG_READ_1_1_2 | \
FLASH_FLAG_READ_1_2_2 | \
FLASH_FLAG_READ_1_1_4 | \
FLASH_FLAG_READ_1_4_4 | \
FLASH_FLAG_WRITE_1_1_4)
{ "w25q80", 0xef4014, 0, 64 * 1024, 16, W25Q_FLAG, 80, NULL },
{ "w25q16", 0xef4015, 0, 64 * 1024, 32, W25Q_FLAG, 80, NULL },
{ "w25q32", 0xef4016, 0, 64 * 1024, 64, W25Q_FLAG, 80, NULL },
{ "w25q64", 0xef4017, 0, 64 * 1024, 128, W25Q_FLAG, 80, NULL },
/* Sentinel */
{ NULL, 0x000000, 0, 0, 0, 0, 0, NULL },
};
static struct stfsm_seq stfsm_seq_en_32bit_addr;/* Dynamically populated */
static struct stfsm_seq stfsm_seq_read_jedec = {
.data_size = TRANSFER_SIZE(8),
.seq_opc[0] = (SEQ_OPC_PADS_1 |
SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_RDID)),
.seq = {
STFSM_INST_CMD1,
STFSM_INST_DATA_READ,
STFSM_INST_STOP,
},
.seq_cfg = (SEQ_CFG_PADS_1 |
SEQ_CFG_READNOTWRITE |
SEQ_CFG_CSDEASSERT |
SEQ_CFG_STARTSEQ),
};
static struct stfsm_seq stfsm_seq_erase_sector = {
/* 'addr_cfg' configured during initialisation */
.seq_opc = {
(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_WREN) | SEQ_OPC_CSDEASSERT),
(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_SE)),
},
.seq = {
STFSM_INST_CMD1,
STFSM_INST_CMD2,
STFSM_INST_ADD1,
STFSM_INST_ADD2,
STFSM_INST_STOP,
},
.seq_cfg = (SEQ_CFG_PADS_1 |
SEQ_CFG_READNOTWRITE |
SEQ_CFG_CSDEASSERT |
SEQ_CFG_STARTSEQ),
};
static int stfsm_n25q_en_32bit_addr_seq(struct stfsm_seq *seq)
{
seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_EN4B_ADDR));
seq->seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_WREN) |
SEQ_OPC_CSDEASSERT);
seq->seq[0] = STFSM_INST_CMD2;
seq->seq[1] = STFSM_INST_CMD1;
seq->seq[2] = STFSM_INST_WAIT;
seq->seq[3] = STFSM_INST_STOP;
seq->seq_cfg = (SEQ_CFG_PADS_1 |
SEQ_CFG_ERASE |
SEQ_CFG_READNOTWRITE |
SEQ_CFG_CSDEASSERT |
SEQ_CFG_STARTSEQ);
return 0;
}
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 void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf,
const uint32_t size)
{
uint32_t remaining = size >> 2;
uint32_t avail;
uint32_t words;
dev_dbg(fsm->dev, "Reading %d bytes from FIFO\n", size);
BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
while (remaining) {
for (;;) {
avail = stfsm_fifo_available(fsm);
if (avail)
break;
udelay(1);
}
words = min(avail, remaining);
remaining -= words;
readsl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
buf += words;
}
}
static int stfsm_enter_32bit_addr(struct stfsm *fsm, int enter)
{
struct stfsm_seq *seq = &stfsm_seq_en_32bit_addr;
uint32_t cmd = enter ? FLASH_CMD_EN4B_ADDR : FLASH_CMD_EX4B_ADDR;
seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(cmd) |
SEQ_OPC_CSDEASSERT);
stfsm_load_seq(fsm, seq);
stfsm_wait_seq(fsm);
return 0;
}
/*
* SoC reset on 'boot-from-spi' systems
*
* Certain modes of operation cause the Flash device to enter a particular state
* for a period of time (e.g. 'Erase Sector', 'Quad Enable', and 'Enter 32-bit
* Addr' commands). On boot-from-spi systems, it is important to consider what
* happens if a warm reset occurs during this period. The SPIBoot controller
* assumes that Flash device is in its default reset state, 24-bit address mode,
* and ready to accept commands. This can be achieved using some form of
* on-board logic/controller to force a device POR in response to a SoC-level
* reset or by making use of the device reset signal if available (limited
* number of devices only).
*
* Failure to take such precautions can cause problems following a warm reset.
* For some operations (e.g. ERASE), there is little that can be done. For
* other modes of operation (e.g. 32-bit addressing), options are often
* available that can help minimise the window in which a reset could cause a
* problem.
*
*/
static bool stfsm_can_handle_soc_reset(struct stfsm *fsm)
{
/* Reset signal is available on the board and supported by the device */
if (fsm->reset_signal && fsm->info->flags & FLASH_FLAG_RESET)
return true;
/* Board-level logic forces a power-on-reset */
if (fsm->reset_por)
return true;
/* Reset is not properly handled and may result in failure to reboot */
return false;
}
/* Configure 'addr_cfg' according to addressing mode */
static void stfsm_prepare_erasesec_seq(struct stfsm *fsm,
struct stfsm_seq *seq)
{
int addr1_cycles = fsm->info->flags & FLASH_FLAG_32BIT_ADDR ? 16 : 8;
seq->addr_cfg = (ADR_CFG_CYCLES_ADD1(addr1_cycles) |
ADR_CFG_PADS_1_ADD1 |
ADR_CFG_CYCLES_ADD2(16) |
ADR_CFG_PADS_1_ADD2 |
ADR_CFG_CSDEASSERT_ADD2);
}
/* Search for preferred configuration based on available flags */
static struct seq_rw_config *
stfsm_search_seq_rw_configs(struct stfsm *fsm,
struct seq_rw_config cfgs[])
{
struct seq_rw_config *config;
int flags = fsm->info->flags;
for (config = cfgs; config->cmd != 0; config++)
if ((config->flags & flags) == config->flags)
return config;
return NULL;
}
/* Prepare a READ/WRITE sequence according to configuration parameters */
static void stfsm_prepare_rw_seq(struct stfsm *fsm,
struct stfsm_seq *seq,
struct seq_rw_config *cfg)
{
int addr1_cycles, addr2_cycles;
int i = 0;
memset(seq, 0, sizeof(*seq));
/* Add READ/WRITE OPC */
seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(cfg->cmd));
/* Add WREN OPC for a WRITE sequence */
if (cfg->write)
seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_WREN) |
SEQ_OPC_CSDEASSERT);
/* Address configuration (24 or 32-bit addresses) */
addr1_cycles = (fsm->info->flags & FLASH_FLAG_32BIT_ADDR) ? 16 : 8;
addr1_cycles /= cfg->addr_pads;
addr2_cycles = 16 / cfg->addr_pads;
seq->addr_cfg = ((addr1_cycles & 0x3f) << 0 | /* ADD1 cycles */
(cfg->addr_pads - 1) << 6 | /* ADD1 pads */
(addr2_cycles & 0x3f) << 16 | /* ADD2 cycles */
((cfg->addr_pads - 1) << 22)); /* ADD2 pads */
/* Data/Sequence configuration */
seq->seq_cfg = ((cfg->data_pads - 1) << 16 |
SEQ_CFG_STARTSEQ |
SEQ_CFG_CSDEASSERT);
if (!cfg->write)
seq->seq_cfg |= SEQ_CFG_READNOTWRITE;
/* Mode configuration (no. of pads taken from addr cfg) */
seq->mode = ((cfg->mode_data & 0xff) << 0 | /* data */
(cfg->mode_cycles & 0x3f) << 16 | /* cycles */
(cfg->addr_pads - 1) << 22); /* pads */
/* Dummy configuration (no. of pads taken from addr cfg) */
seq->dummy = ((cfg->dummy_cycles & 0x3f) << 16 | /* cycles */
(cfg->addr_pads - 1) << 22); /* pads */
/* Instruction sequence */
i = 0;
if (cfg->write)
seq->seq[i++] = STFSM_INST_CMD2;
seq->seq[i++] = STFSM_INST_CMD1;
seq->seq[i++] = STFSM_INST_ADD1;
seq->seq[i++] = STFSM_INST_ADD2;
if (cfg->mode_cycles)
seq->seq[i++] = STFSM_INST_MODE;
if (cfg->dummy_cycles)
seq->seq[i++] = STFSM_INST_DUMMY;
seq->seq[i++] =
cfg->write ? STFSM_INST_DATA_WRITE : STFSM_INST_DATA_READ;
seq->seq[i++] = STFSM_INST_STOP;
}
static int stfsm_search_prepare_rw_seq(struct stfsm *fsm,
struct stfsm_seq *seq,
struct seq_rw_config *cfgs)
{
struct seq_rw_config *config;
config = stfsm_search_seq_rw_configs(fsm, cfgs);
if (!config) {
dev_err(fsm->dev, "failed to find suitable config\n");
return -EINVAL;
}
stfsm_prepare_rw_seq(fsm, seq, config);
return 0;
}
static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *const jedec)
{
const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
uint32_t tmp[2];
stfsm_load_seq(fsm, seq);
stfsm_read_fifo(fsm, tmp, 8);
memcpy(jedec, tmp, 5);
stfsm_wait_seq(fsm);
}
static struct flash_info *stfsm_jedec_probe(struct stfsm *fsm)
{
struct flash_info *info;
u16 ext_jedec;
u32 jedec;
u8 id[5];
stfsm_read_jedec(fsm, id);
jedec = id[0] << 16 | id[1] << 8 | id[2];
/*
* JEDEC also defines an optional "extended device information"
* string for after vendor-specific data, after the three bytes
* we use here. Supporting some chips might require using it.
*/
ext_jedec = id[3] << 8 | id[4];
dev_dbg(fsm->dev, "JEDEC = 0x%08x [%02x %02x %02x %02x %02x]\n",
jedec, id[0], id[1], id[2], id[3], id[4]);
for (info = flash_types; info->name; info++) {
if (info->jedec_id == jedec) {
if (info->ext_id && info->ext_id != ext_jedec)
continue;
return info;
}
}
dev_err(fsm->dev, "Unrecognized JEDEC id %06x\n", jedec);
return NULL;
}
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 void stfsm_fetch_platform_configs(struct platform_device *pdev)
{
struct stfsm *fsm = platform_get_drvdata(pdev);
struct device_node *np = pdev->dev.of_node;
struct regmap *regmap;
uint32_t boot_device_reg;
uint32_t boot_device_spi;
uint32_t boot_device; /* Value we read from *boot_device_reg */
int ret;
/* Booting from SPI NOR Flash is the default */
fsm->booted_from_spi = true;
regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
if (IS_ERR(regmap))
goto boot_device_fail;
fsm->reset_signal = of_property_read_bool(np, "st,reset-signal");
fsm->reset_por = of_property_read_bool(np, "st,reset-por");
/* Where in the syscon the boot device information lives */
ret = of_property_read_u32(np, "st,boot-device-reg", &boot_device_reg);
if (ret)
goto boot_device_fail;
/* Boot device value when booted from SPI NOR */
ret = of_property_read_u32(np, "st,boot-device-spi", &boot_device_spi);
if (ret)
goto boot_device_fail;
ret = regmap_read(regmap, boot_device_reg, &boot_device);
if (ret)
goto boot_device_fail;
if (boot_device != boot_device_spi)
fsm->booted_from_spi = false;
return;
boot_device_fail:
dev_warn(&pdev->dev,
"failed to fetch boot device, assuming boot from SPI\n");
}
static int stfsm_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct flash_info *info;
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;
}
stfsm_fetch_platform_configs(pdev);
/* Detect SPI FLASH device */
info = stfsm_jedec_probe(fsm);
if (!info)
return -ENODEV;
fsm->info = info;
/* Use device size to determine address width */
if (info->sector_size * info->n_sectors > 0x1000000)
info->flags |= FLASH_FLAG_32BIT_ADDR;
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;
fsm->mtd.size = info->sector_size * info->n_sectors;
fsm->mtd.erasesize = info->sector_size;
dev_err(&pdev->dev,
"Found serial flash device: %s\n"
" size = %llx (%lldMiB) erasesize = 0x%08x (%uKiB)\n",
info->name,
(long long)fsm->mtd.size, (long long)(fsm->mtd.size >> 20),
fsm->mtd.erasesize, (fsm->mtd.erasesize >> 10));
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 <angus.clark@st.com>");
MODULE_DESCRIPTION("ST SPI FSM driver");
MODULE_LICENSE("GPL");
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