On Mon, Mar 14, 2022 at 2:12 PM Patrick Venture <vent...@google.com> wrote:
> Tested: Verified at24c02 driver happy and contents matched
> expectations.
>
> Signed-off-by: Patrick Venture <vent...@google.com>
> Reviewed-by: Hao Wu <wuhao...@google.com>
> ---
> hw/nvram/eeprom_at24c.c | 52 +++++++++++++++++++++++++++--------------
> 1 file changed, 35 insertions(+), 17 deletions(-)
>
> diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c
> index 01a3093600..abf9898f94 100644
> --- a/hw/nvram/eeprom_at24c.c
> +++ b/hw/nvram/eeprom_at24c.c
> @@ -45,6 +45,8 @@ struct EEPROMState {
> bool changed;
> /* during WRITE, # of address bytes transfered */
> uint8_t haveaddr;
> + /* whether it's 8-bit addressed or 16-bit */
> + bool eightbit;
>
> uint8_t *mem;
>
> @@ -85,7 +87,7 @@ uint8_t at24c_eeprom_recv(I2CSlave *s)
> EEPROMState *ee = AT24C_EE(s);
> uint8_t ret;
>
> - if (ee->haveaddr == 1) {
> + if (ee->haveaddr == 1 && !ee->eightbit) {
> return 0xff;
> }
>
> @@ -102,26 +104,35 @@ int at24c_eeprom_send(I2CSlave *s, uint8_t data)
> {
> EEPROMState *ee = AT24C_EE(s);
>
> - if (ee->haveaddr < 2) {
> - ee->cur <<= 8;
> - ee->cur |= data;
> + if (ee->haveaddr < 1) {
> + ee->cur = data;
> ee->haveaddr++;
> - if (ee->haveaddr == 2) {
> - ee->cur %= ee->rsize;
> + if (ee->eightbit) {
> DPRINTK("Set pointer %04x\n", ee->cur);
> }
> + return 0;
> + } else if (ee->haveaddr < 2) {
> + if (!ee->eightbit) {
> + ee->cur <<= 8;
> + ee->cur |= data;
> + ee->haveaddr++;
> + if (ee->haveaddr == 2) {
> + ee->cur %= ee->rsize;
> + DPRINTK("Set pointer %04x\n", ee->cur);
> + }
>
> - } else {
> - if (ee->writable) {
> - DPRINTK("Send %02x\n", data);
> - ee->mem[ee->cur] = data;
> - ee->changed = true;
> - } else {
> - DPRINTK("Send error %02x read-only\n", data);
> + return 0;
> }
> - ee->cur = (ee->cur + 1u) % ee->rsize;
> + }
>
> + if (ee->writable) {
> + DPRINTK("Send %02x\n", data);
> + ee->mem[ee->cur] = data;
> + ee->changed = true;
> + } else {
> + DPRINTK("Send error %02x read-only\n", data);
> }
> + ee->cur = (ee->cur + 1u) % ee->rsize;
>
> return 0;
> }
> @@ -131,12 +142,16 @@ static void at24c_eeprom_realize(DeviceState *dev,
> Error **errp)
> EEPROMState *ee = AT24C_EE(dev);
>
> if (ee->blk) {
> + /* blk length is a minimum of 1 sector. */
> int64_t len = blk_getlength(ee->blk);
>
> if (len != ee->rsize) {
> - error_setg(errp, "%s: Backing file size %" PRId64 " != %u",
> - TYPE_AT24C_EE, len, ee->rsize);
> - return;
> + /* for the at24c01 and at24c02, they are smaller than a
> sector. */
> + if (ee->rsize >= BDRV_SECTOR_SIZE) {
> + error_setg(errp, "%s: Backing file size %" PRId64 " !=
> %u",
> + TYPE_AT24C_EE, len, ee->rsize);
> + return;
> + }
> }
>
> if (blk_set_perm(ee->blk, BLK_PERM_CONSISTENT_READ |
> BLK_PERM_WRITE,
> @@ -148,6 +163,9 @@ static void at24c_eeprom_realize(DeviceState *dev,
> Error **errp)
> }
> }
>
> + if (ee->rsize < 512) {
> + ee->eightbit = true;
> + }
>
Why 512? The eeprom sizes for the parts seem to grow exponentially, so c01
is 128, then c02 is 256, then 512. So I check for the two smaller
effectively. Might warrant a comment.
> ee->mem = g_malloc0(ee->rsize);
> }
>
> --
> 2.35.1.723.g4982287a31-goog
>
>
