Re: [Qemu-arm] [Qemu-devel] [PATCH v5 27/28] hw/block/pflash_cfi02: Document commands

[Alistair Francis]

On Thu, Jun 27, 2019 at 1:58 PM Philippe Mathieu-Daudé
<address@hidden> wrote:
>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Alistair

> ---
>  hw/block/pflash_cfi02.c | 40 +++++++++++++++++++---------------------
>  1 file changed, 19 insertions(+), 21 deletions(-)
>
> diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c
> index e9519cbae8..db9dc7d8fb 100644
> --- a/hw/block/pflash_cfi02.c
> +++ b/hw/block/pflash_cfi02.c
> @@ -327,7 +327,7 @@ static uint64_t pflash_read(void *opaque, hwaddr offset, 
> unsigned int width)
>          pfl->wcycle = 0;
>          pfl->cmd = 0;
>          /* fall through to the read code */
> -    case 0x80:
> +    case 0x80: /* Erase (unlock) */
>          /* We accept reads during second unlock sequence... */
>      case 0x00:
>          if (pflash_erase_suspend_mode(pfl) &&
> @@ -342,8 +342,7 @@ static uint64_t pflash_read(void *opaque, hwaddr offset, 
> unsigned int width)
>          /* Flash area read */
>          ret = pflash_data_read(pfl, offset, width);
>          break;
> -    case 0x90:
> -        /* flash ID read */
> +    case 0x90: /* flash ID read */
>          switch (boff) {
>          case 0x00:
>          case 0x01:
> @@ -364,11 +363,11 @@ static uint64_t pflash_read(void *opaque, hwaddr 
> offset, unsigned int width)
>          }
>          DPRINTF("%s: ID " TARGET_FMT_plx " %" PRIx64 "\n", __func__, boff, 
> ret);
>          break;
> -    case 0x10:
> -    case 0x30:
> +    case 0x10: /* Chip Erase */
> +    case 0x30: /* Sector Erase */
>          /* Toggle bit 2 during erase, but not program. */
>          toggle_dq2(pfl);
> -    case 0xA0:
> +    case 0xA0: /* Program */
>          /* Toggle bit 6 */
>          toggle_dq6(pfl);
>          /* Status register read */
> @@ -470,7 +469,7 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>              return;
>          }
>          /* Handle erase resume in erase suspend mode, otherwise reset. */
> -        if (cmd == 0x30) {
> +        if (cmd == 0x30) { /* Erase Resume */
>              if (pflash_erase_suspend_mode(pfl)) {
>                  /* Resume the erase. */
>                  timer_mod(&pfl->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) 
> +
> @@ -485,7 +484,7 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>              goto reset_flash;
>          }
>          /* Ignore erase suspend. */
> -        if (cmd == 0xB0) {
> +        if (cmd == 0xB0) { /* Erase Suspend */
>              return;
>          }
>          if (boff != pfl->unlock_addr0 || cmd != 0xAA) {
> @@ -516,9 +515,9 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>          case 0x20:
>              pfl->bypass = 1;
>              goto do_bypass;
> -        case 0x80:
> -        case 0x90:
> -        case 0xA0:
> +        case 0x80: /* Erase */
> +        case 0x90: /* Autoselect */
> +        case 0xA0: /* Program */
>              pfl->cmd = cmd;
>              DPRINTF("%s: starting command %02x\n", __func__, cmd);
>              break;
> @@ -529,10 +528,10 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>          break;
>      case 3:
>          switch (pfl->cmd) {
> -        case 0x80:
> +        case 0x80: /* Erase */
>              /* We need another unlock sequence */
>              goto check_unlock0;
> -        case 0xA0:
> +        case 0xA0: /* Program */
>              if (pflash_erase_suspend_mode(pfl) &&
>                  pflash_sector_is_erasing(pfl, offset)) {
>                  /* Ignore writes to erasing sectors. */
> @@ -562,7 +561,7 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>              if (pfl->bypass)
>                  goto do_bypass;
>              goto reset_flash;
> -        case 0x90:
> +        case 0x90: /* Autoselect */
>              if (pfl->bypass && cmd == 0x00) {
>                  /* Unlock bypass reset */
>                  goto reset_flash;
> @@ -585,11 +584,11 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>          }
>      case 4:
>          switch (pfl->cmd) {
> -        case 0xA0:
> +        case 0xA0: /* Program */
>              /* Ignore writes while flash data write is occurring */
>              /* As we suppose write is immediate, this should never happen */
>              return;
> -        case 0x80:
> +        case 0x80: /* Erase */
>              goto check_unlock1;
>          default:
>              /* Should never happen */
> @@ -604,7 +603,7 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>              goto reset_flash;
>          }
>          switch (cmd) {
> -        case 0x10:
> +        case 0x10: /* Chip Erase */
>              if (boff != pfl->unlock_addr0) {
>                  DPRINTF("%s: chip erase: invalid address " TARGET_FMT_plx 
> "\n",
>                          __func__, offset);
> @@ -621,8 +620,7 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>              timer_mod(&pfl->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
>                        (1ULL << pfl->cfi_table[0x22]) * SCALE_MS);
>              break;
> -        case 0x30:
> -            /* Sector erase */
> +        case 0x30: /* Sector erase */
>              pflash_sector_erase(pfl, offset);
>              break;
>          default:
> @@ -633,10 +631,10 @@ static void pflash_write(void *opaque, hwaddr offset, 
> uint64_t value,
>          break;
>      case 6:
>          switch (pfl->cmd) {
> -        case 0x10:
> +        case 0x10: /* Chip Erase */
>              /* Ignore writes during chip erase */
>              return;
> -        case 0x30:
> +        case 0x30: /* Sector erase */
>              if (cmd == 0xB0) {
>                  /*
>                   * If erase suspend happens during the erase timeout (so DQ3 
> is
> --
> 2.20.1
>
>