вт, 13 дек. 2022 г. в 09:27, Neha Malcom Francis <n-fran...@ti.com>:
>
> EEPROM detection logic in ti_i2c_eeprom_get() involves figuring out
> whether addressing is 1-byte or 2-byte. There are currently different
> behaviours seen across boards as documented in commit bf6376642fe8
> ("board: ti: common: board_detect: Fix EEPROM read quirk"). Adding to
> the list, we see that there are 2-byte EEPROMs that read properly
> with 1-byte addressing with no offset.
>
> For ti_i2c_eeprom_am6_get where eeprom parse operation is dynamic, the
> earlier commit d2ab2a2bafd5 ("board: ti: common: board_detect: Fix
> EEPROM read quirk for AM6 style data") tried to resolve this by running
> ti_i2c_eeprom_get() twice. However this commit along with its former
> commit fails on J7 platforms where EEPROM successfully return back the
> header on 1-byte addressing and continues to do so until an offset is
> introduced. So the second read incorrectly determines the EEPROM as
> 1-byte addressing.
>
> A more generic solution is introduced here to solve
> this issue: 1-byte read without offset and 1-byte read with offset. If
> both passes, it follows 1-byte addressing else we proceed with 2-byte
> addressing check.
>
> Tested on J721E, J7200, DRA7xx, AM64x
>
> Signed-off-by: Neha Malcom Francis <n-fran...@ti.com>
> Fixes: d2ab2a2bafd5 (board: ti: common: board_detect: Fix EEPROM read quirk
> for AM6 style data)
> Fixes: bf6376642fe8 (board: ti: common: board_detect: Fix EEPROM read quirk)
Tested-By: Matwey V. Kornilov <matwey.korni...@gmail.com>
> ---
> board/ti/common/board_detect.c | 46 +++++++++++++++++++++++++---------
> 1 file changed, 34 insertions(+), 12 deletions(-)
>
> Changes since v1:
> - modified algorithm for boards that do not have CONFIG_DM_I2C
> enabled as well
>
> diff --git a/board/ti/common/board_detect.c b/board/ti/common/board_detect.c
> index c37629fe8a..9b32076ab9 100644
> --- a/board/ti/common/board_detect.c
> +++ b/board/ti/common/board_detect.c
> @@ -87,6 +87,8 @@ static int __maybe_unused ti_i2c_eeprom_get(int bus_addr,
> int dev_addr,
> u32 header, u32 size, uint8_t *ep)
> {
> int rc;
> + uint8_t offset_test;
> + bool one_byte_addressing = true;
>
> #if CONFIG_IS_ENABLED(DM_I2C)
> struct udevice *dev;
> @@ -114,8 +116,23 @@ static int __maybe_unused ti_i2c_eeprom_get(int
> bus_addr, int dev_addr,
> */
> (void)dm_i2c_read(dev, 0, ep, size);
>
> + if (*((u32 *)ep) != header)
> + one_byte_addressing = false;
> +
> + /*
> + * Handle case of bad 2 byte eeproms that responds to 1 byte
> addressing
> + * but gets stuck in const addressing when read requests are performed
> + * on offsets. We perform an offset test to make sure it is not a 2
> byte
> + * eeprom that works with 1 byte addressing but just without an offset
> + */
> +
> + rc = dm_i2c_read(dev, 0x1, &offset_test, sizeof(offset_test));
> +
> + if (*((u32 *)ep) != (header & 0xFF))
> + one_byte_addressing = false;
> +
> /* Corrupted data??? */
> - if (*((u32 *)ep) != header) {
> + if (!one_byte_addressing) {
> /*
> * read the eeprom header using i2c again, but use only a
> * 2 byte address (some newer boards need this..)
> @@ -151,8 +168,23 @@ static int __maybe_unused ti_i2c_eeprom_get(int
> bus_addr, int dev_addr,
> */
> (void)i2c_read(dev_addr, 0x0, byte, ep, size);
>
> + if (*((u32 *)ep) != header)
> + one_byte_addressing = false;
> +
> + /*
> + * Handle case of bad 2 byte eeproms that responds to 1 byte
> addressing
> + * but gets stuck in const addressing when read requests are performed
> + * on offsets. We perform an offset test to make sure it is not a 2
> byte
> + * eeprom that works with 1 byte addressing but just without an offset
> + */
> +
> + rc = i2c_read(dev, 0x1, byte, &offset_test, sizeof(offset_test));
> +
> + if (*((u32 *)ep) != (header & 0xFF))
> + one_byte_addressing = false;
> +
> /* Corrupted data??? */
> - if (*((u32 *)ep) != header) {
> + if (!one_byte_addressing) {
> /*
> * read the eeprom header using i2c again, but use only a
> * 2 byte address (some newer boards need this..)
> @@ -444,16 +476,6 @@ int __maybe_unused ti_i2c_eeprom_am6_get(int bus_addr,
> int dev_addr,
> if (rc)
> return rc;
>
> - /*
> - * Handle case of bad 2 byte eeproms that responds to 1 byte
> addressing
> - * but gets stuck in const addressing when read requests are performed
> - * on offsets. We re-read the board ID to ensure we have sane data
> back
> - */
> - rc = ti_i2c_eeprom_get(bus_addr, dev_addr, TI_EEPROM_HEADER_MAGIC,
> - sizeof(board_id), (uint8_t *)&board_id);
> - if (rc)
> - return rc;
> -
> if (board_id.header.id != TI_AM6_EEPROM_RECORD_BOARD_ID) {
> pr_err("%s: Invalid board ID record!\n", __func__);
> return -EINVAL;
> --
> 2.34.1
>
--
With best regards,
Matwey V. Kornilov
