[openocd.git] / src / flash / nor / stmsmi.c

/***************************************************************************
 *   Copyright (C) 2010 by Antonio Borneo <borneo.antonio@gmail.com>       *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

/* STM Serial Memory Interface (SMI) controller is a SPI bus controller
 * specifically designed for SPI memories.
 * Only SPI "mode 3" (CPOL=1 and CPHA=1) is supported.
 * Two working modes are available:
 * - SW mode: the SPI is controlled by SW. Any custom commands can be sent
 *   on the bus.
 * - HW mode: the SPI but is under SMI control. Memory content is directly
 *   accessible in CPU memory space. CPU can read, write and execute memory
 *   content. */

/* ATTENTION:
 * To have flash memory mapped in CPU memory space, the SMI controller
 * have to be in "HW mode". This requires following constraints:
 * 1) The command "reset init" have to initialize SMI controller and put
 *    it in HW mode;
 * 2) every command in this file have to return to prompt in HW mode. */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "imp.h"
#include "spi.h"
#include <jtag/jtag.h>
#include <helper/time_support.h>

#define SMI_READ_REG(a) (_SMI_READ_REG(a))
#define _SMI_READ_REG(a)                        \
{                                                                       \
        int __a;                                                \
        uint32_t __v;                                   \
                                                                        \
        __a = target_read_u32(target, io_base + (a), &__v); \
        if (__a != ERROR_OK)                    \
                return __a;                                     \
        __v;                                                    \
}

#define SMI_WRITE_REG(a, v)                     \
{                                                                       \
        int __r;                                                \
                                                                        \
        __r = target_write_u32(target, io_base + (a), (v)); \
        if (__r != ERROR_OK)                    \
                return __r;                                     \
}

#define SMI_POLL_TFF(timeout)           \
{                                                                       \
        int __r;                                                \
                                                                        \
        __r = poll_tff(target, io_base, timeout); \
        if (__r != ERROR_OK)                    \
                return __r;                                     \
}

#define SMI_SET_SW_MODE()       SMI_WRITE_REG(SMI_CR1, \
        SMI_READ_REG(SMI_CR1) | SMI_SW_MODE)
#define SMI_SET_HWWB_MODE() SMI_WRITE_REG(SMI_CR1, \
        (SMI_READ_REG(SMI_CR1) | SMI_WB_MODE) & ~SMI_SW_MODE)
#define SMI_SET_HW_MODE()       SMI_WRITE_REG(SMI_CR1, \
        SMI_READ_REG(SMI_CR1) & ~(SMI_SW_MODE | SMI_WB_MODE))
#define SMI_CLEAR_TFF()         SMI_WRITE_REG(SMI_SR, ~SMI_TFF)

#define SMI_BANK_SIZE      (0x01000000)

#define SMI_CR1 (0x00) /* Control register 1 */
#define SMI_CR2 (0x04) /* Control register 2 */
#define SMI_SR  (0x08) /* Status register */
#define SMI_TR  (0x0c) /* TX */
#define SMI_RR  (0x10) /* RX */

/* fields in SMI_CR1 */
#define SMI_SW_MODE       0x10000000 /* set to enable SW Mode */
#define SMI_WB_MODE       0x20000000 /* Write Burst Mode */

/* fields in SMI_CR2 */
#define SMI_TX_LEN_1      0x00000001 /* data length = 1 byte */
#define SMI_TX_LEN_4      0x00000004 /* data length = 4 byte */
#define SMI_RX_LEN_3      0x00000030 /* data length = 3 byte */
#define SMI_SEND          0x00000080 /* Send data */
#define SMI_RSR           0x00000400 /* reads status reg */
#define SMI_WE            0x00000800 /* Write Enable */
#define SMI_SEL_BANK0     0x00000000 /* Select Bank0 */
#define SMI_SEL_BANK1     0x00001000 /* Select Bank1 */
#define SMI_SEL_BANK2     0x00002000 /* Select Bank2 */
#define SMI_SEL_BANK3     0x00003000 /* Select Bank3 */

/* fields in SMI_SR */
#define SMI_TFF           0x00000100 /* Transfer Finished Flag */

/* Commands */
#define SMI_READ_ID       0x0000009F /* Read Flash Identification */

/* Timeout in ms */
#define SMI_CMD_TIMEOUT   (100)
#define SMI_PROBE_TIMEOUT (100)
#define SMI_MAX_TIMEOUT  (3000)

struct stmsmi_flash_bank {
        int probed;
        uint32_t io_base;
        uint32_t bank_num;
        const struct flash_device *dev;
};

struct stmsmi_target {
        char *name;
        uint32_t tap_idcode;
        uint32_t smi_base;
        uint32_t io_base;
};

static const struct stmsmi_target target_devices[] = {
        /* name,          tap_idcode, smi_base,   io_base */
        { "SPEAr3xx/6xx", 0x07926041, 0xf8000000, 0xfc000000 },
        { "STR75x",       0x4f1f0041, 0x80000000, 0x90000000 },
        { NULL,           0,          0,          0 }
};

FLASH_BANK_COMMAND_HANDLER(stmsmi_flash_bank_command)
{
        struct stmsmi_flash_bank *stmsmi_info;

        LOG_DEBUG("%s", __func__);

        if (CMD_ARGC < 6)
                return ERROR_COMMAND_SYNTAX_ERROR;

        stmsmi_info = malloc(sizeof(struct stmsmi_flash_bank));
        if (stmsmi_info == NULL) {
                LOG_ERROR("not enough memory");
                return ERROR_FAIL;
        }

        bank->driver_priv = stmsmi_info;
        stmsmi_info->probed = 0;

        return ERROR_OK;
}

/* Poll transmit finished flag */
/* timeout in ms */
static int poll_tff(struct target *target, uint32_t io_base, int timeout)
{
        int64_t endtime;

        if (SMI_READ_REG(SMI_SR) & SMI_TFF)
                return ERROR_OK;

        endtime = timeval_ms() + timeout;
        do {
                alive_sleep(1);
                if (SMI_READ_REG(SMI_SR) & SMI_TFF)
                        return ERROR_OK;
        } while (timeval_ms() < endtime);

        LOG_ERROR("Timeout while polling TFF");
        return ERROR_FLASH_OPERATION_FAILED;
}

/* Read the status register of the external SPI flash chip.
 * The operation is triggered by setting SMI_RSR bit.
 * SMI sends the proper SPI command (0x05) and returns value in SMI_SR */
static int read_status_reg(struct flash_bank *bank, uint32_t *status)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;

        /* clear transmit finished flag */
        SMI_CLEAR_TFF();

        /* Read status */
        SMI_WRITE_REG(SMI_CR2, stmsmi_info->bank_num | SMI_RSR);

        /* Poll transmit finished flag */
        SMI_POLL_TFF(SMI_CMD_TIMEOUT);

        /* clear transmit finished flag */
        SMI_CLEAR_TFF();

        *status = SMI_READ_REG(SMI_SR) & 0x0000ffff;

        /* clean-up SMI_CR2 */
        SMI_WRITE_REG(SMI_CR2, 0); /* AB: Required ? */

        return ERROR_OK;
}

/* check for WIP (write in progress) bit in status register */
/* timeout in ms */
static int wait_till_ready(struct flash_bank *bank, int timeout)
{
        uint32_t status;
        int retval;
        int64_t endtime;

        endtime = timeval_ms() + timeout;
        do {
                /* read flash status register */
                retval = read_status_reg(bank, &status);
                if (retval != ERROR_OK)
                        return retval;

                if ((status & SPIFLASH_BSY_BIT) == 0)
                        return ERROR_OK;
                alive_sleep(1);
        } while (timeval_ms() < endtime);

        LOG_ERROR("timeout");
        return ERROR_FAIL;
}

/* Send "write enable" command to SPI flash chip.
 * The operation is triggered by setting SMI_WE bit, and SMI sends
 * the proper SPI command (0x06) */
static int smi_write_enable(struct flash_bank *bank)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;
        uint32_t status;
        int retval;

        /* Enter in HW mode */
        SMI_SET_HW_MODE(); /* AB: is this correct ?*/

        /* clear transmit finished flag */
        SMI_CLEAR_TFF();

        /* Send write enable command */
        SMI_WRITE_REG(SMI_CR2, stmsmi_info->bank_num | SMI_WE);

        /* Poll transmit finished flag */
        SMI_POLL_TFF(SMI_CMD_TIMEOUT);

        /* read flash status register */
        retval = read_status_reg(bank, &status);
        if (retval != ERROR_OK)
                return retval;

        /* Check write enabled */
        if ((status & SPIFLASH_WE_BIT) == 0) {
                LOG_ERROR("Cannot enable write to flash. Status=0x%08" PRIx32, status);
                return ERROR_FAIL;
        }

        return ERROR_OK;
}

static uint32_t erase_command(struct stmsmi_flash_bank *stmsmi_info,
        uint32_t offset)
{
        union {
                uint32_t command;
                uint8_t x[4];
        } cmd;

        cmd.x[0] = stmsmi_info->dev->erase_cmd;
        cmd.x[1] = offset >> 16;
        cmd.x[2] = offset >> 8;
        cmd.x[3] = offset;

        return cmd.command;
}

static int smi_erase_sector(struct flash_bank *bank, int sector)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;
        uint32_t cmd;
        int retval;

        retval = smi_write_enable(bank);
        if (retval != ERROR_OK)
                return retval;

        /* Switch to SW mode to send sector erase command */
        SMI_SET_SW_MODE();

        /* clear transmit finished flag */
        SMI_CLEAR_TFF();

        /* send SPI command "block erase" */
        cmd = erase_command(stmsmi_info, bank->sectors[sector].offset);
        SMI_WRITE_REG(SMI_TR, cmd);
        SMI_WRITE_REG(SMI_CR2, stmsmi_info->bank_num | SMI_SEND | SMI_TX_LEN_4);

        /* Poll transmit finished flag */
        SMI_POLL_TFF(SMI_CMD_TIMEOUT);

        /* poll WIP for end of self timed Sector Erase cycle */
        retval = wait_till_ready(bank, SMI_MAX_TIMEOUT);
        if (retval != ERROR_OK)
                return retval;

        return ERROR_OK;
}

static int stmsmi_erase(struct flash_bank *bank, int first, int last)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;
        int retval = ERROR_OK;
        int sector;

        LOG_DEBUG("%s: from sector %d to sector %d", __func__, first, last);

        if (target->state != TARGET_HALTED) {
                LOG_ERROR("Target not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        if ((first < 0) || (last < first) || (last >= bank->num_sectors)) {
                LOG_ERROR("Flash sector invalid");
                return ERROR_FLASH_SECTOR_INVALID;
        }

        if (!(stmsmi_info->probed)) {
                LOG_ERROR("Flash bank not probed");
                return ERROR_FLASH_BANK_NOT_PROBED;
        }

        for (sector = first; sector <= last; sector++) {
                if (bank->sectors[sector].is_protected) {
                        LOG_ERROR("Flash sector %d protected", sector);
                        return ERROR_FAIL;
                }
        }

        if (stmsmi_info->dev->erase_cmd == 0x00)
                return ERROR_FLASH_OPER_UNSUPPORTED;

        for (sector = first; sector <= last; sector++) {
                retval = smi_erase_sector(bank, sector);
                if (retval != ERROR_OK)
                        break;
                keep_alive();
        }

        /* Switch to HW mode before return to prompt */
        SMI_SET_HW_MODE();
        return retval;
}

static int stmsmi_protect(struct flash_bank *bank, int set,
        int first, int last)
{
        int sector;

        for (sector = first; sector <= last; sector++)
                bank->sectors[sector].is_protected = set;
        return ERROR_OK;
}

static int smi_write_buffer(struct flash_bank *bank, const uint8_t *buffer,
        uint32_t address, uint32_t len)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;
        int retval;

        LOG_DEBUG("%s: address=0x%08" PRIx32 " len=0x%08" PRIx32,
                        __func__, address, len);

        retval = smi_write_enable(bank);
        if (retval != ERROR_OK)
                return retval;

        /* HW mode, write burst mode */
        SMI_SET_HWWB_MODE();

        retval = target_write_buffer(target, address, len, buffer);
        if (retval != ERROR_OK)
                return retval;

        return ERROR_OK;
}

static int stmsmi_write(struct flash_bank *bank, const uint8_t *buffer,
        uint32_t offset, uint32_t count)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;
        uint32_t cur_count, page_size, page_offset;
        int sector;
        int retval = ERROR_OK;

        LOG_DEBUG("%s: offset=0x%08" PRIx32 " count=0x%08" PRIx32,
                __func__, offset, count);

        if (target->state != TARGET_HALTED) {
                LOG_ERROR("Target not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        if (offset + count > stmsmi_info->dev->size_in_bytes) {
                LOG_WARNING("Write pasts end of flash. Extra data discarded.");
                count = stmsmi_info->dev->size_in_bytes - offset;
        }

        /* Check sector protection */
        for (sector = 0; sector < bank->num_sectors; sector++) {
                /* Start offset in or before this sector? */
                /* End offset in or behind this sector? */
                if ((offset <
                                (bank->sectors[sector].offset + bank->sectors[sector].size))
                        && ((offset + count - 1) >= bank->sectors[sector].offset)
                        && bank->sectors[sector].is_protected) {
                        LOG_ERROR("Flash sector %d protected", sector);
                        return ERROR_FAIL;
                }
        }

        /* if no valid page_size, use reasonable default */
        page_size = stmsmi_info->dev->pagesize ?
                stmsmi_info->dev->pagesize : SPIFLASH_DEF_PAGESIZE;

        /* unaligned buffer head */
        if (count > 0 && (offset & 3) != 0) {
                cur_count = 4 - (offset & 3);
                if (cur_count > count)
                        cur_count = count;
                retval = smi_write_buffer(bank, buffer, bank->base + offset,
                        cur_count);
                if (retval != ERROR_OK)
                        goto err;
                offset += cur_count;
                buffer += cur_count;
                count -= cur_count;
        }

        page_offset = offset % page_size;
        /* central part, aligned words */
        while (count >= 4) {
                /* clip block at page boundary */
                if (page_offset + count > page_size)
                        cur_count = page_size - page_offset;
                else
                        cur_count = count & ~3;

                retval = smi_write_buffer(bank, buffer, bank->base + offset,
                        cur_count);
                if (retval != ERROR_OK)
                        goto err;

                page_offset = 0;
                buffer += cur_count;
                offset += cur_count;
                count -= cur_count;

                keep_alive();
        }

        /* buffer tail */
        if (count > 0)
                retval = smi_write_buffer(bank, buffer, bank->base + offset, count);

err:
        /* Switch to HW mode before return to prompt */
        SMI_SET_HW_MODE();
        return retval;
}

/* Return ID of flash device */
/* On exit, SW mode is kept */
static int read_flash_id(struct flash_bank *bank, uint32_t *id)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base = stmsmi_info->io_base;
        int retval;

        if (target->state != TARGET_HALTED) {
                LOG_ERROR("Target not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        /* poll WIP */
        retval = wait_till_ready(bank, SMI_PROBE_TIMEOUT);
        if (retval != ERROR_OK)
                return retval;

        /* enter in SW mode */
        SMI_SET_SW_MODE();

        /* clear transmit finished flag */
        SMI_CLEAR_TFF();

        /* Send SPI command "read ID" */
        SMI_WRITE_REG(SMI_TR, SMI_READ_ID);
        SMI_WRITE_REG(SMI_CR2,
                stmsmi_info->bank_num | SMI_SEND | SMI_RX_LEN_3 | SMI_TX_LEN_1);

        /* Poll transmit finished flag */
        SMI_POLL_TFF(SMI_CMD_TIMEOUT);

        /* clear transmit finished flag */
        SMI_CLEAR_TFF();

        /* read ID from Receive Register */
        *id = SMI_READ_REG(SMI_RR) & 0x00ffffff;
        return ERROR_OK;
}

static int stmsmi_probe(struct flash_bank *bank)
{
        struct target *target = bank->target;
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        uint32_t io_base, sectorsize;
        struct flash_sector *sectors;
        uint32_t id = 0; /* silence uninitialized warning */
        const struct stmsmi_target *target_device;
        int retval;

        if (stmsmi_info->probed)
                free(bank->sectors);
        stmsmi_info->probed = 0;

        for (target_device = target_devices ; target_device->name ; ++target_device)
                if (target_device->tap_idcode == target->tap->idcode)
                        break;
        if (!target_device->name) {
                LOG_ERROR("Device ID 0x%" PRIx32 " is not known as SMI capable",
                                target->tap->idcode);
                return ERROR_FAIL;
        }

        switch (bank->base - target_device->smi_base) {
                case 0:
                        stmsmi_info->bank_num = SMI_SEL_BANK0;
                        break;
                case SMI_BANK_SIZE:
                        stmsmi_info->bank_num = SMI_SEL_BANK1;
                        break;
                case 2*SMI_BANK_SIZE:
                        stmsmi_info->bank_num = SMI_SEL_BANK2;
                        break;
                case 3*SMI_BANK_SIZE:
                        stmsmi_info->bank_num = SMI_SEL_BANK3;
                        break;
                default:
                        LOG_ERROR("Invalid SMI base address 0x%" PRIx32, bank->base);
                        return ERROR_FAIL;
        }
        io_base = target_device->io_base;
        stmsmi_info->io_base = io_base;

        LOG_DEBUG("Valid SMI on device %s at address 0x%" PRIx32,
                target_device->name, bank->base);

        /* read and decode flash ID; returns in SW mode */
        retval = read_flash_id(bank, &id);
        SMI_SET_HW_MODE();
        if (retval != ERROR_OK)
                return retval;

        stmsmi_info->dev = NULL;
        for (const struct flash_device *p = flash_devices; p->name ; p++)
                if (p->device_id == id) {
                        stmsmi_info->dev = p;
                        break;
                }

        if (!stmsmi_info->dev) {
                LOG_ERROR("Unknown flash device (ID 0x%08" PRIx32 ")", id);
                return ERROR_FAIL;
        }

        LOG_INFO("Found flash device \'%s\' (ID 0x%08" PRIx32 ")",
                stmsmi_info->dev->name, stmsmi_info->dev->device_id);

        /* Set correct size value */
        bank->size = stmsmi_info->dev->size_in_bytes;
        if (bank->size <= (1UL << 16))
                LOG_WARNING("device needs 2-byte addresses - not implemented");
        if (bank->size > (1UL << 24))
                LOG_WARNING("device needs paging or 4-byte addresses - not implemented");

        /* if no sectors, treat whole bank as single sector */
        sectorsize = stmsmi_info->dev->sectorsize ?
                stmsmi_info->dev->sectorsize : stmsmi_info->dev->size_in_bytes;

        /* create and fill sectors array */
        bank->num_sectors =
                stmsmi_info->dev->size_in_bytes / sectorsize;
        sectors = malloc(sizeof(struct flash_sector) * bank->num_sectors);
        if (sectors == NULL) {
                LOG_ERROR("not enough memory");
                return ERROR_FAIL;
        }

        for (int sector = 0; sector < bank->num_sectors; sector++) {
                sectors[sector].offset = sector * sectorsize;
                sectors[sector].size = sectorsize;
                sectors[sector].is_erased = -1;
                sectors[sector].is_protected = 1;
        }

        bank->sectors = sectors;
        stmsmi_info->probed = 1;
        return ERROR_OK;
}

static int stmsmi_auto_probe(struct flash_bank *bank)
{
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;
        if (stmsmi_info->probed)
                return ERROR_OK;
        return stmsmi_probe(bank);
}

static int stmsmi_protect_check(struct flash_bank *bank)
{
        /* Nothing to do. Protection is only handled in SW. */
        return ERROR_OK;
}

static int get_stmsmi_info(struct flash_bank *bank, char *buf, int buf_size)
{
        struct stmsmi_flash_bank *stmsmi_info = bank->driver_priv;

        if (!(stmsmi_info->probed)) {
                snprintf(buf, buf_size,
                        "\nSMI flash bank not probed yet\n");
                return ERROR_OK;
        }

        snprintf(buf, buf_size, "\nSMI flash information:\n"
                "  Device \'%s\' (ID 0x%08" PRIx32 ")\n",
                stmsmi_info->dev->name, stmsmi_info->dev->device_id);

        return ERROR_OK;
}

struct flash_driver stmsmi_flash = {
        .name = "stmsmi",
        .flash_bank_command = stmsmi_flash_bank_command,
        .erase = stmsmi_erase,
        .protect = stmsmi_protect,
        .write = stmsmi_write,
        .read = default_flash_read,
        .probe = stmsmi_probe,
        .auto_probe = stmsmi_auto_probe,
        .erase_check = default_flash_blank_check,
        .protect_check = stmsmi_protect_check,
        .info = get_stmsmi_info,
        .free_driver_priv = default_flash_free_driver_priv,
};