winbond.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <console/console.h>
#include <commonlib/helpers.h>
#include <spi_flash.h>
#include <spi-generic.h>
#include <delay.h>
#include <lib.h>
 
#include "spi_flash_internal.h"
#include "spi_winbond.h"
 
union status_reg1 {
        uint8_t u;
        struct {
                uint8_t busy : 1;
                uint8_t wel  : 1;
                uint8_t bp   : 3;
                uint8_t tb   : 1;
                uint8_t sec  : 1;
                uint8_t srp0 : 1;
        } bp3;
        struct {
                uint8_t busy : 1;
                uint8_t wel  : 1;
                uint8_t bp   : 4;
                uint8_t tb   : 1;
                uint8_t srp0 : 1;
        } bp4;
};
 
union status_reg2 {
        uint8_t u;
        struct {
                uint8_t srp1 : 1;
                uint8_t   qe : 1;
                uint8_t  res : 1;
                uint8_t   lb : 3;
                uint8_t  cmp : 1;
                uint8_t  sus : 1;
        };
};
 
struct status_regs {
        union {
                struct {
#if defined(__BIG_ENDIAN)
                        union status_reg2 reg2;
                        union status_reg1 reg1;
#else
                        union status_reg1 reg1;
                        union status_reg2 reg2;
#endif
                };
                u16 u;
        };
};
 
static const struct spi_flash_part_id flash_table[] = {
        {
                /* W25P80 */
                .id[0]                          = 0x2014,
                .nr_sectors_shift               = 8,
        },
        {
                /* W25P16 */
                .id[0]                          = 0x2015,
                .nr_sectors_shift               = 9,
        },
        {
                /* W25P32 */
                .id[0]                          = 0x2016,
                .nr_sectors_shift               = 10,
        },
        {
                /* W25X80 */
                .id[0]                          = 0x3014,
                .nr_sectors_shift               = 8,
                .fast_read_dual_output_support  = 1,
        },
        {
                /* W25X16 */
                .id[0]                          = 0x3015,
                .nr_sectors_shift               = 9,
                .fast_read_dual_output_support  = 1,
        },
        {
                /* W25X32 */
                .id[0]                          = 0x3016,
                .nr_sectors_shift               = 10,
                .fast_read_dual_output_support  = 1,
        },
        {
                /* W25X64 */
                .id[0]                          = 0x3017,
                .nr_sectors_shift               = 11,
                .fast_read_dual_output_support  = 1,
        },
        {
                /* W25Q80_V */
                .id[0]                          = 0x4014,
                .nr_sectors_shift               = 8,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
        },
        {
                /* W25Q16_V */
                .id[0]                          = 0x4015,
                .nr_sectors_shift               = 9,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 3,
        },
        {
                /* W25Q16DW */
                .id[0]                          = 0x6015,
                .nr_sectors_shift               = 9,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 3,
        },
        {
                /* W25Q32_V */
                .id[0]                          = 0x4016,
                .nr_sectors_shift               = 10,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 3,
        },
        {
                /* W25Q32DW */
                .id[0]                          = 0x6016,
                .nr_sectors_shift               = 10,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 3,
        },
        {
                /* W25Q64_V */
                .id[0]                          = 0x4017,
                .nr_sectors_shift               = 11,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 17,
                .bp_bits                        = 3,
        },
        {
                /* W25Q64DW */
                .id[0]                          = 0x6017,
                .nr_sectors_shift               = 11,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 17,
                .bp_bits                        = 3,
        },
        {
                /* W25Q64JW */
                .id[0]                          = 0x8017,
                .nr_sectors_shift               = 11,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 17,
                .bp_bits                        = 3,
        },
        {
                /* W25Q128_V */
                .id[0]                          = 0x4018,
                .nr_sectors_shift               = 12,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 18,
                .bp_bits                        = 3,
        },
        {
                /* W25Q128FW */
                .id[0]                          = 0x6018,
                .nr_sectors_shift               = 12,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 18,
                .bp_bits                        = 3,
        },
        {
                /* W25Q128J */
                .id[0]                          = 0x7018,
                .nr_sectors_shift               = 12,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 18,
                .bp_bits                        = 3,
        },
        {
                /* W25Q128JW */
                .id[0]                          = 0x8018,
                .nr_sectors_shift               = 12,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 18,
                .bp_bits                        = 3,
        },
        {
                /* W25Q512NW-IM */
                .id[0]                          = 0x8020,
                .nr_sectors_shift               = 14,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 4,
        },
        {
                /* W25Q256_V */
                .id[0]                          = 0x4019,
                .nr_sectors_shift               = 13,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 4,
        },
        {
                /* W25Q256J */
                .id[0]                          = 0x7019,
                .nr_sectors_shift               = 13,
                .fast_read_dual_output_support  = 1,
                .fast_read_dual_io_support      = 1,
                .protection_granularity_shift   = 16,
                .bp_bits                        = 4,
        },
};
 
/*
 * Convert BPx, TB and CMP to a region.
 * SEC (if available) must be zero.
 */
static void winbond_bpbits_to_region(const size_t granularity,
                                     const u8 bp,
                                     bool tb,
                                     const bool cmp,
                                     const size_t flash_size,
                                     struct region *out)
{
        size_t protected_size =
                MIN(bp ? granularity << (bp - 1) : 0, flash_size);
 
        if (cmp) {
                protected_size = flash_size - protected_size;
                tb = !tb;
        }
 
        out->offset = tb ? 0 : flash_size - protected_size;
        out->size = protected_size;
}
 
/*
 * Available on all devices.
 * Read block protect bits from Status/Status2 Reg.
 * Converts block protection bits to a region.
 *
 * Returns:
 * -1    on error
 *  1    if region is covered by write protection
 *  0    if a part of region isn't covered by write protection
 */
static int winbond_get_write_protection(const struct spi_flash *flash,
                                        const struct region *region)
{
        const struct spi_flash_part_id *params;
        struct region wp_region;
        union status_reg2 reg2;
        u8 bp, tb;
        int ret;
 
        params = flash->part;
 
        if (!params)
                return -1;
 
        const size_t granularity = (1 << params->protection_granularity_shift);
 
        union status_reg1 reg1 = { .u = 0 };
 
        ret = spi_flash_cmd(&flash->spi, flash->status_cmd, &reg1.u,
                            sizeof(reg1.u));
        if (ret)
                return ret;
 
        if (params->bp_bits == 3) {
                if (reg1.bp3.sec) {
                        // FIXME: not supported
                        return -1;
                }
 
                bp = reg1.bp3.bp;
                tb = reg1.bp3.tb;
        } else if (params->bp_bits == 4) {
                bp = reg1.bp4.bp;
                tb = reg1.bp4.tb;
        } else {
                // FIXME: not supported
                return -1;
        }
 
        ret = spi_flash_cmd(&flash->spi, CMD_W25_RDSR2, &reg2.u,
                            sizeof(reg2.u));
        if (ret)
                return ret;
 
        winbond_bpbits_to_region(granularity, bp, tb, reg2.cmp, flash->size,
                                 &wp_region);
 
        if (!region_sz(&wp_region)) {
                printk(BIOS_DEBUG, "WINBOND: flash isn't protected\n");
 
                return 0;
        }
 
        printk(BIOS_DEBUG, "WINBOND: flash protected range 0x%08zx-0x%08zx\n",
               region_offset(&wp_region), region_end(&wp_region));
 
        return region_is_subregion(&wp_region, region);
}
 
/**
 * Common method to write some bit of the status register 1 & 2 at the same
 * time. Only change bits that are one in @mask.
 * Compare the final result to make sure that the register isn't locked.
 *
 * @param mask: The bits that are affected by @val
 * @param val: The bits to write
 * @param non_volatile: Make setting permanent
 *
 * @return 0 on success
 */
static int winbond_flash_cmd_status(const struct spi_flash *flash,
                                    const u16 mask,
                                    const u16 val,
                                    const bool non_volatile)
{
        struct {
                u8 cmd;
                u16 sreg;
        } __packed cmdbuf;
        u8 reg8;
        int ret;
 
        if (!flash)
                return -1;
 
        ret = spi_flash_cmd(&flash->spi, CMD_W25_RDSR, &reg8, sizeof(reg8));
        if (ret)
                return ret;
 
        cmdbuf.sreg = reg8;
 
        ret = spi_flash_cmd(&flash->spi, CMD_W25_RDSR2, &reg8, sizeof(reg8));
        if (ret)
                return ret;
 
        cmdbuf.sreg |= reg8 << 8;
 
        if ((val & mask) == (cmdbuf.sreg & mask))
                return 0;
 
        if (non_volatile) {
                ret = spi_flash_cmd(&flash->spi, CMD_W25_WREN, NULL, 0);
        } else {
                ret = spi_flash_cmd(&flash->spi, CMD_VOLATILE_SREG_WREN, NULL,
                                    0);
        }
        if (ret)
                return ret;
 
        cmdbuf.sreg &= ~mask;
        cmdbuf.sreg |= val & mask;
        cmdbuf.cmd = CMD_W25_WRSR;
 
        /* Legacy method of writing status register 1 & 2 */
        ret = spi_flash_cmd_write(&flash->spi, (u8 *)&cmdbuf, sizeof(cmdbuf),
                                  NULL, 0);
        if (ret)
                return ret;
 
        if (non_volatile) {
                /* Wait tw */
                ret = spi_flash_cmd_wait_ready(flash, WINBOND_FLASH_TIMEOUT);
                if (ret)
                        return ret;
        } else {
                /* Wait tSHSL */
                udelay(1);
        }
 
        /* Now read the status register to make sure it's not locked */
        ret = spi_flash_cmd(&flash->spi, CMD_W25_RDSR, &reg8, sizeof(reg8));
        if (ret)
                return ret;
 
        cmdbuf.sreg = reg8;
 
        ret = spi_flash_cmd(&flash->spi, CMD_W25_RDSR2, &reg8, sizeof(reg8));
        if (ret)
                return ret;
 
        cmdbuf.sreg |= reg8 << 8;
 
        printk(BIOS_DEBUG, "WINBOND: SREG=%02x SREG2=%02x\n",
               cmdbuf.sreg & 0xff,
               cmdbuf.sreg >> 8);
 
        /* Compare against expected result */
        if ((val & mask) != (cmdbuf.sreg & mask)) {
                printk(BIOS_ERR, "WINBOND: SREG is locked!\n");
                ret = -1;
        }
 
        return ret;
}
 
/*
 * Available on all devices.
 * Protect a region starting from start of flash or end of flash.
 * The caller must provide a supported protected region size.
 * SEC isn't supported and set to zero.
 * Write block protect bits to Status/Status2 Reg.
 * Optionally lock the status register if lock_sreg is set with the provided
 * mode.
 *
 * @param flash: The flash to operate on
 * @param region: The region to write protect
 * @param mode: Optional status register lock-down mode
 *
 * @return 0 on success
 */
static int
winbond_set_write_protection(const struct spi_flash *flash,
                             const struct region *region,
                             const enum spi_flash_status_reg_lockdown mode)
{
        const struct spi_flash_part_id *params;
        struct status_regs mask, val;
        struct region wp_region;
        u8 cmp, bp, tb;
        int ret;
 
        /* Need to touch TOP or BOTTOM */
        if (region_offset(region) != 0 && region_end(region) != flash->size)
                return -1;
 
        params = flash->part;
 
        if (!params)
                return -1;
 
        if (params->bp_bits != 3 && params->bp_bits != 4) {
                /* FIXME: not implemented */
                return -1;
        }
 
        wp_region = *region;
 
        if (region_offset(&wp_region) == 0)
                tb = 1;
        else
                tb = 0;
 
        if (region_sz(&wp_region) > flash->size / 2) {
                cmp = 1;
                wp_region.offset = tb ? 0 : region_sz(&wp_region);
                wp_region.size = flash->size - region_sz(&wp_region);
                tb = !tb;
        } else {
                cmp = 0;
        }
 
        if (region_sz(&wp_region) == 0) {
                bp = 0;
        } else if (IS_POWER_OF_2(region_sz(&wp_region)) &&
                   (region_sz(&wp_region) >=
                    (1 << params->protection_granularity_shift))) {
                bp = log2(region_sz(&wp_region)) -
                          params->protection_granularity_shift + 1;
        } else {
                printk(BIOS_ERR, "WINBOND: ERROR: unsupported region size\n");
                return -1;
        }
 
        /* Write block protection bits */
 
        if (params->bp_bits == 3) {
                val.reg1 = (union status_reg1) {
                        .bp3 = { .bp = bp, .tb = tb, .sec = 0 }
                };
                mask.reg1 = (union status_reg1) {
                        .bp3 = { .bp = ~0, .tb = 1, .sec = 1 }
                };
        } else {
                val.reg1 = (union status_reg1) {
                        .bp4 = { .bp = bp, .tb = tb }
                };
                mask.reg1 = (union status_reg1) {
                        .bp4 = { .bp = ~0, .tb = 1 }
                };
        }
 
        val.reg2 = (union status_reg2) { .cmp = cmp };
        mask.reg2 = (union status_reg2) { .cmp = 1 };
 
        if (mode != SPI_WRITE_PROTECTION_PRESERVE) {
                u8 srp;
                switch (mode) {
                case SPI_WRITE_PROTECTION_NONE:
                        srp = 0;
                break;
                case SPI_WRITE_PROTECTION_PIN:
                        srp = 1;
                break;
                case SPI_WRITE_PROTECTION_REBOOT:
                        srp = 2;
                break;
                case SPI_WRITE_PROTECTION_PERMANENT:
                        srp = 3;
                break;
                default:
                        return -1;
                }
 
                if (params->bp_bits == 3) {
                        val.reg1.bp3.srp0 = !!(srp & 1);
                        mask.reg1.bp3.srp0 = 1;
                } else {
                        val.reg1.bp4.srp0 = !!(srp & 1);
                        mask.reg1.bp4.srp0 = 1;
                }
 
                val.reg2.srp1 = !!(srp & 2);
                mask.reg2.srp1 = 1;
        }
 
        ret = winbond_flash_cmd_status(flash, mask.u, val.u, true);
        if (ret)
                return ret;
 
        printk(BIOS_DEBUG, "WINBOND: write-protection set to range "
               "0x%08zx-0x%08zx\n", region_offset(region), region_end(region));
 
        return ret;
}
 
static const struct spi_flash_protection_ops spi_flash_protection_ops = {
        .get_write = winbond_get_write_protection,
        .set_write = winbond_set_write_protection,
};
 
const struct spi_flash_vendor_info spi_flash_winbond_vi = {
        .id = VENDOR_ID_WINBOND,
        .page_size_shift = 8,
        .sector_size_kib_shift = 2,
        .match_id_mask[0] = 0xffff,
        .ids = flash_table,
        .nr_part_ids = ARRAY_SIZE(flash_table),
        .desc = &spi_flash_pp_0x20_sector_desc,
        .prot_ops = &spi_flash_protection_ops,
};