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authorJiri Prchal <jiri.prchal@aksignal.cz>2021-06-11 11:45:58 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-06-11 12:23:10 +0200
commitfd307a4ad332ef50be5569c92490219e7cd84ce5 (patch)
tree6683353455acad103535cdbceb9af084ff50531a /drivers
parent989f77e3fdee2e8f414dd1da9b6397d8763d414e (diff)
nvmem: prepare basics for FRAM support
Added enum and string for FRAM (ferroelectric RAM) to expose it as file named "fram". Added documentation of sysfs file. Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz> Link: https://lore.kernel.org/r/20210611094601.95131-2-jiri.prchal@aksignal.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/misc/eeprom/Kconfig5
-rw-r--r--drivers/misc/eeprom/at25.c161
-rw-r--r--drivers/nvmem/core.c4
3 files changed, 138 insertions, 32 deletions
diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
index 0f791bfdc1f5..f0a7531f354c 100644
--- a/drivers/misc/eeprom/Kconfig
+++ b/drivers/misc/eeprom/Kconfig
@@ -32,12 +32,13 @@ config EEPROM_AT24
will be called at24.
config EEPROM_AT25
- tristate "SPI EEPROMs from most vendors"
+ tristate "SPI EEPROMs (FRAMs) from most vendors"
depends on SPI && SYSFS
select NVMEM
select NVMEM_SYSFS
help
- Enable this driver to get read/write support to most SPI EEPROMs,
+ Enable this driver to get read/write support to most SPI EEPROMs
+ and Cypress FRAMs,
after you configure the board init code to know about each eeprom
on your target board.
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index b76e4901b4a4..6e26de68a001 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;
@@ -58,6 +69,9 @@ struct at25_data {
*/
#define EE_TIMEOUT 25
+#define IS_EEPROM 0
+#define IS_FRAM 1
+
/*-------------------------------------------------------------------------*/
#define io_limit PAGE_SIZE /* bytes */
@@ -129,6 +143,51 @@ 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", 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 +362,39 @@ 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", .data = (const void *)IS_EEPROM },
+ { .compatible = "cypress,fm25", .data = (const void *)IS_FRAM },
+ { }
+};
+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;
+ int is_fram = 0;
+
+ match = of_match_device(of_match_ptr(at25_of_match), &spi->dev);
+ if (match)
+ is_fram = (int)match->data;
/* 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 +413,51 @@ 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 +476,22 @@ 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,
};
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index b3c28a2d4c10..4d1c4f83b22f 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -180,6 +180,7 @@ static const char * const nvmem_type_str[] = {
[NVMEM_TYPE_EEPROM] = "EEPROM",
[NVMEM_TYPE_OTP] = "OTP",
[NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
+ [NVMEM_TYPE_FRAM] = "FRAM",
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -359,6 +360,9 @@ static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
if (!config->base_dev)
return -EINVAL;
+ if (config->type == NVMEM_TYPE_FRAM)
+ bin_attr_nvmem_eeprom_compat.attr.name = "fram";
+
nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
nvmem->eeprom.size = nvmem->size;