diff options
Diffstat (limited to 'drivers/misc/eeprom/at25.c')
| -rw-r--r-- | drivers/misc/eeprom/at25.c | 158 |
1 files changed, 128 insertions, 30 deletions
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index b76e4901b4a4..4d09b672ac3c 100644 --- a/drivers/misc/eeprom/at25.c +++ b/drivers/misc/eeprom/at25.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* * at25.c -- support most SPI EEPROMs, such as Atmel AT25 models + * and Cypress FRAMs FM25 models * * Copyright (C) 2006 David Brownell */ @@ -16,6 +17,9 @@ #include <linux/spi/spi.h> #include <linux/spi/eeprom.h> #include <linux/property.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/math.h> /* * NOTE: this is an *EEPROM* driver. The vagaries of product naming @@ -27,6 +31,7 @@ * AT25M02, AT25128B */ +#define FM25_SN_LEN 8 /* serial number length */ struct at25_data { struct spi_device *spi; struct mutex lock; @@ -34,6 +39,7 @@ struct at25_data { unsigned addrlen; struct nvmem_config nvmem_config; struct nvmem_device *nvmem; + u8 sernum[FM25_SN_LEN]; }; #define AT25_WREN 0x06 /* latch the write enable */ @@ -42,6 +48,9 @@ struct at25_data { #define AT25_WRSR 0x01 /* write status register */ #define AT25_READ 0x03 /* read byte(s) */ #define AT25_WRITE 0x02 /* write byte(s)/sector */ +#define FM25_SLEEP 0xb9 /* enter sleep mode */ +#define FM25_RDID 0x9f /* read device ID */ +#define FM25_RDSN 0xc3 /* read S/N */ #define AT25_SR_nRDY 0x01 /* nRDY = write-in-progress */ #define AT25_SR_WEN 0x02 /* write enable (latched) */ @@ -51,6 +60,8 @@ struct at25_data { #define AT25_INSTR_BIT3 0x08 /* Additional address bit in instr */ +#define FM25_ID_LEN 9 /* ID length */ + #define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */ /* Specs often allow 5 msec for a page write, sometimes 20 msec; @@ -129,6 +140,51 @@ static int at25_ee_read(void *priv, unsigned int offset, return status; } +/* + * read extra registers as ID or serial number + */ +static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command, + int len) +{ + int status; + struct spi_transfer t[2]; + struct spi_message m; + + spi_message_init(&m); + memset(t, 0, sizeof(t)); + + t[0].tx_buf = &command; + t[0].len = 1; + spi_message_add_tail(&t[0], &m); + + t[1].rx_buf = buf; + t[1].len = len; + spi_message_add_tail(&t[1], &m); + + mutex_lock(&at25->lock); + + status = spi_sync(at25->spi, &m); + dev_dbg(&at25->spi->dev, "read %d aux bytes --> %d\n", len, status); + + mutex_unlock(&at25->lock); + return status; +} + +static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct at25_data *at25; + + at25 = dev_get_drvdata(dev); + return sysfs_emit(buf, "%*ph\n", (int)sizeof(at25->sernum), at25->sernum); +} +static DEVICE_ATTR_RO(sernum); + +static struct attribute *sernum_attrs[] = { + &dev_attr_sernum.attr, + NULL, +}; +ATTRIBUTE_GROUPS(sernum); + static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count) { struct at25_data *at25 = priv; @@ -303,34 +359,39 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip) return 0; } +static const struct of_device_id at25_of_match[] = { + { .compatible = "atmel,at25",}, + { .compatible = "cypress,fm25",}, + { } +}; +MODULE_DEVICE_TABLE(of, at25_of_match); + static int at25_probe(struct spi_device *spi) { struct at25_data *at25 = NULL; struct spi_eeprom chip; int err; int sr; - int addrlen; + u8 id[FM25_ID_LEN]; + u8 sernum[FM25_SN_LEN]; + int i; + const struct of_device_id *match; + bool is_fram = 0; + + match = of_match_device(of_match_ptr(at25_of_match), &spi->dev); + if (match && !strcmp(match->compatible, "cypress,fm25")) + is_fram = 1; /* Chip description */ if (!spi->dev.platform_data) { - err = at25_fw_to_chip(&spi->dev, &chip); - if (err) - return err; + if (!is_fram) { + err = at25_fw_to_chip(&spi->dev, &chip); + if (err) + return err; + } } else chip = *(struct spi_eeprom *)spi->dev.platform_data; - /* For now we only support 8/16/24 bit addressing */ - if (chip.flags & EE_ADDR1) - addrlen = 1; - else if (chip.flags & EE_ADDR2) - addrlen = 2; - else if (chip.flags & EE_ADDR3) - addrlen = 3; - else { - dev_dbg(&spi->dev, "unsupported address type\n"); - return -EINVAL; - } - /* Ping the chip ... the status register is pretty portable, * unlike probing manufacturer IDs. We do expect that system * firmware didn't write it in the past few milliseconds! @@ -349,9 +410,51 @@ static int at25_probe(struct spi_device *spi) at25->chip = chip; at25->spi = spi; spi_set_drvdata(spi, at25); - at25->addrlen = addrlen; - at25->nvmem_config.type = NVMEM_TYPE_EEPROM; + if (is_fram) { + /* Get ID of chip */ + fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN); + if (id[6] != 0xc2) { + dev_err(&spi->dev, + "Error: no Cypress FRAM (id %02x)\n", id[6]); + return -ENODEV; + } + /* set size found in ID */ + if (id[7] < 0x21 || id[7] > 0x26) { + dev_err(&spi->dev, "Error: unsupported size (id %02x)\n", id[7]); + return -ENODEV; + } + chip.byte_len = int_pow(2, id[7] - 0x21 + 4) * 1024; + + if (at25->chip.byte_len > 64 * 1024) + at25->chip.flags |= EE_ADDR3; + else + at25->chip.flags |= EE_ADDR2; + + 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]; + } + + at25->chip.page_size = PAGE_SIZE; + strncpy(at25->chip.name, "fm25", sizeof(at25->chip.name)); + } + + /* For now we only support 8/16/24 bit addressing */ + if (at25->chip.flags & EE_ADDR1) + at25->addrlen = 1; + else if (at25->chip.flags & EE_ADDR2) + at25->addrlen = 2; + else if (at25->chip.flags & EE_ADDR3) + at25->addrlen = 3; + else { + dev_dbg(&spi->dev, "unsupported address type\n"); + return -EINVAL; + } + + at25->nvmem_config.type = is_fram ? NVMEM_TYPE_FRAM : NVMEM_TYPE_EEPROM; at25->nvmem_config.name = dev_name(&spi->dev); at25->nvmem_config.dev = &spi->dev; at25->nvmem_config.read_only = chip.flags & EE_READONLY; @@ -370,27 +473,22 @@ static int at25_probe(struct spi_device *spi) if (IS_ERR(at25->nvmem)) return PTR_ERR(at25->nvmem); - dev_info(&spi->dev, "%d %s %s eeprom%s, pagesize %u\n", - (chip.byte_len < 1024) ? chip.byte_len : (chip.byte_len / 1024), - (chip.byte_len < 1024) ? "Byte" : "KByte", - at25->chip.name, - (chip.flags & EE_READONLY) ? " (readonly)" : "", - at25->chip.page_size); + dev_info(&spi->dev, "%d %s %s %s%s, pagesize %u\n", + (chip.byte_len < 1024) ? chip.byte_len : (chip.byte_len / 1024), + (chip.byte_len < 1024) ? "Byte" : "KByte", + at25->chip.name, is_fram ? "fram" : "eeprom", + (chip.flags & EE_READONLY) ? " (readonly)" : "", + at25->chip.page_size); return 0; } /*-------------------------------------------------------------------------*/ -static const struct of_device_id at25_of_match[] = { - { .compatible = "atmel,at25", }, - { } -}; -MODULE_DEVICE_TABLE(of, at25_of_match); - static struct spi_driver at25_driver = { .driver = { .name = "at25", .of_match_table = at25_of_match, + .dev_groups = sernum_groups, }, .probe = at25_probe, }; |