From 3fcd9a0fbb7dfbad3caa5057054d21b903157079 Mon Sep 17 00:00:00 2001 From: Patrick Wicki Date: Tue, 20 Jan 2026 14:06:02 +0100 Subject: [PATCH] eeprom: at25: add support for Infineon Cypress QSN FRAMs Add support for Infineon Cypress CY15****QSN FRAM chips. Unlike the QN variants these chips have an 8 byte JEDEC ID. The layout of the serial number matches that of already supported chips like the CY15B204QN, so make the read-out unconditional. Tested with the CY15B204QSN. According to Infineon datasheets, all QSN variants appear to share a consistent pattern so the size should be correctly detected based on the density bits in the ID: CY15B201QSN: 0x00 00 00 00 06 82 54 40, density_id: 8: 1Mb CY15B102QSN: 0x00 00 00 00 06 82 51 48, density_id: 9: 2Mb CY15B204QSN: 0x00 00 00 00 06 82 54 50, density_id: 10: 4Mb CY15V108QSN: 0x00 00 00 00 06 82 52 58, density_id: 11: 8Mb Signed-off-by: Patrick Wicki Reviewed-by: Alexander Sverdlin Tested-by: Alexander Sverdlin Link: https://patch.msgid.link/20260120130603.1066559-1-patrick@subset.ch Signed-off-by: Greg Kroah-Hartman --- drivers/misc/eeprom/at25.c | 50 +++++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 20 deletions(-) diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index 883dfd0ed6583..5b00921d07d2e 100644 --- a/drivers/misc/eeprom/at25.c +++ b/drivers/misc/eeprom/at25.c @@ -398,30 +398,40 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) id[i] = id[j]; id[j] = tmp; } - if (id[6] != 0xc2) { - dev_err(dev, "Error: no Cypress FRAM with device ID (manufacturer ID bank 7: %02x)\n", id[6]); - return -ENODEV; - } - switch (id[7]) { - case 0x21 ... 0x26: - chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024; - break; - case 0x2a ... 0x30: - /* CY15B102QN ... CY15B116QN */ - chip->byte_len = BIT(((id[7] >> 1) & 0xf) + 13); - break; - default: - dev_err(dev, "Error: unsupported size (id %02x)\n", id[7]); + if (id[6] == 0xc2) { + switch (id[7]) { + case 0x21 ... 0x26: + chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024; + break; + case 0x2a ... 0x30: + /* CY15B102QN ... CY15B116QN */ + chip->byte_len = BIT(((id[7] >> 1) & 0xf) + 13); + break; + default: + dev_err(dev, "Error: unsupported size (id %02x)\n", id[7]); + return -ENODEV; + } + } else if (id[2] == 0x82 && id[3] == 0x06) { + switch (id[1]) { + case 0x51 ... 0x54: + /* CY15B102QSN ... CY15B204QSN */ + chip->byte_len = BIT(((id[0] >> 3) & 0x1F) + 9); + break; + default: + dev_err(dev, "Error: unsupported product id %02x\n", id[1]); + return -ENODEV; + } + } else { + dev_err(dev, "Error: unrecognized JEDEC ID format: %*ph\n", + FM25_ID_LEN, id); return -ENODEV; } - if (id[8]) { - fm25_aux_read(at25, sernum, FM25_RDSN, FM25_SN_LEN); - /* Swap byte order */ - for (i = 0; i < FM25_SN_LEN; i++) - at25->sernum[i] = sernum[FM25_SN_LEN - 1 - i]; - } + fm25_aux_read(at25, sernum, FM25_RDSN, FM25_SN_LEN); + /* Swap byte order */ + for (i = 0; i < FM25_SN_LEN; i++) + at25->sernum[i] = sernum[FM25_SN_LEN - 1 - i]; } if (chip->byte_len > 64 * 1024) -- 2.47.3