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Diffstat (limited to 'drivers/misc/eeprom/at25.c')
-rw-r--r--drivers/misc/eeprom/at25.c213
1 files changed, 112 insertions, 101 deletions
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index b38978a3b3ff..c3305bdda69c 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -1,28 +1,27 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * at25.c -- support most SPI EEPROMs, such as Atmel AT25 models
- * and Cypress FRAMs FM25 models
+ * Driver for most of the SPI EEPROMs, such as Atmel AT25 models
+ * and Cypress FRAMs FM25 models.
*
* Copyright (C) 2006 David Brownell
*/
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/slab.h>
+#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
#include <linux/sched.h>
+#include <linux/slab.h>
-#include <linux/nvmem-provider.h>
-#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>
+#include <linux/spi/spi.h>
+
+#include <linux/nvmem-provider.h>
/*
- * NOTE: this is an *EEPROM* driver. The vagaries of product naming
+ * NOTE: this is an *EEPROM* driver. The vagaries of product naming
* mean that some AT25 products are EEPROMs, and others are FLASH.
* Handle FLASH chips with the drivers/mtd/devices/m25p80.c driver,
* not this one!
@@ -33,9 +32,9 @@
#define FM25_SN_LEN 8 /* serial number length */
struct at25_data {
+ struct spi_eeprom chip;
struct spi_device *spi;
struct mutex lock;
- struct spi_eeprom chip;
unsigned addrlen;
struct nvmem_config nvmem_config;
struct nvmem_device *nvmem;
@@ -58,13 +57,14 @@ struct at25_data {
#define AT25_SR_BP1 0x08
#define AT25_SR_WPEN 0x80 /* writeprotect enable */
-#define AT25_INSTR_BIT3 0x08 /* Additional address bit in instr */
+#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;
+/*
+ * Specs often allow 5ms for a page write, sometimes 20ms;
* it's important to recover from write timeouts.
*/
#define EE_TIMEOUT 25
@@ -96,7 +96,7 @@ static int at25_ee_read(void *priv, unsigned int offset,
instr = AT25_READ;
if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
- if (offset >= (1U << (at25->addrlen * 8)))
+ if (offset >= BIT(at25->addrlen * 8))
instr |= AT25_INSTR_BIT3;
*cp++ = instr;
@@ -109,7 +109,7 @@ static int at25_ee_read(void *priv, unsigned int offset,
*cp++ = offset >> 8;
fallthrough;
case 1:
- case 0: /* can't happen: for better codegen */
+ case 0: /* can't happen: for better code generation */
*cp++ = offset >> 0;
}
@@ -126,11 +126,12 @@ static int at25_ee_read(void *priv, unsigned int offset,
mutex_lock(&at25->lock);
- /* Read it all at once.
+ /*
+ * Read it all at once.
*
* REVISIT that's potentially a problem with large chips, if
* other devices on the bus need to be accessed regularly or
- * this chip is clocked very slowly
+ * this chip is clocked very slowly.
*/
status = spi_sync(at25->spi, &m);
dev_dbg(&at25->spi->dev, "read %zu bytes at %d --> %zd\n",
@@ -140,9 +141,7 @@ static int at25_ee_read(void *priv, unsigned int offset,
return status;
}
-/*
- * read extra registers as ID or serial number
- */
+/* Read extra registers as ID or serial number */
static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command,
int len)
{
@@ -208,7 +207,8 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
if (!bounce)
return -ENOMEM;
- /* For write, rollover is within the page ... so we write at
+ /*
+ * For write, rollover is within the page ... so we write at
* most one page, then manually roll over to the next page.
*/
mutex_lock(&at25->lock);
@@ -229,7 +229,7 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
instr = AT25_WRITE;
if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)
- if (offset >= (1U << (at25->addrlen * 8)))
+ if (offset >= BIT(at25->addrlen * 8))
instr |= AT25_INSTR_BIT3;
*cp++ = instr;
@@ -242,7 +242,7 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
*cp++ = offset >> 8;
fallthrough;
case 1:
- case 0: /* can't happen: for better codegen */
+ case 0: /* can't happen: for better code generation */
*cp++ = offset >> 0;
}
@@ -258,8 +258,9 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
if (status < 0)
break;
- /* REVISIT this should detect (or prevent) failed writes
- * to readonly sections of the EEPROM...
+ /*
+ * REVISIT this should detect (or prevent) failed writes
+ * to read-only sections of the EEPROM...
*/
/* Wait for non-busy status */
@@ -306,34 +307,37 @@ static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
{
u32 val;
+ int err;
- memset(chip, 0, sizeof(*chip));
strncpy(chip->name, "at25", sizeof(chip->name));
- if (device_property_read_u32(dev, "size", &val) == 0 ||
- device_property_read_u32(dev, "at25,byte-len", &val) == 0) {
- chip->byte_len = val;
- } else {
+ err = device_property_read_u32(dev, "size", &val);
+ if (err)
+ err = device_property_read_u32(dev, "at25,byte-len", &val);
+ if (err) {
dev_err(dev, "Error: missing \"size\" property\n");
- return -ENODEV;
+ return err;
}
+ chip->byte_len = val;
- if (device_property_read_u32(dev, "pagesize", &val) == 0 ||
- device_property_read_u32(dev, "at25,page-size", &val) == 0) {
- chip->page_size = val;
- } else {
+ err = device_property_read_u32(dev, "pagesize", &val);
+ if (err)
+ err = device_property_read_u32(dev, "at25,page-size", &val);
+ if (err) {
dev_err(dev, "Error: missing \"pagesize\" property\n");
- return -ENODEV;
+ return err;
}
+ chip->page_size = val;
- if (device_property_read_u32(dev, "at25,addr-mode", &val) == 0) {
+ err = device_property_read_u32(dev, "address-width", &val);
+ if (err) {
+ err = device_property_read_u32(dev, "at25,addr-mode", &val);
+ if (err) {
+ dev_err(dev, "Error: missing \"address-width\" property\n");
+ return err;
+ }
chip->flags = (u16)val;
} else {
- if (device_property_read_u32(dev, "address-width", &val)) {
- dev_err(dev,
- "Error: missing \"address-width\" property\n");
- return -ENODEV;
- }
switch (val) {
case 9:
chip->flags |= EE_INSTR_BIT3_IS_ADDR;
@@ -359,16 +363,54 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
return 0;
}
+static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip)
+{
+ struct at25_data *at25 = container_of(chip, struct at25_data, chip);
+ u8 sernum[FM25_SN_LEN];
+ u8 id[FM25_ID_LEN];
+ int i;
+
+ strncpy(chip->name, "fm25", sizeof(chip->name));
+
+ /* Get ID of chip */
+ fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN);
+ if (id[6] != 0xc2) {
+ dev_err(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(dev, "Error: unsupported size (id %02x)\n", id[7]);
+ return -ENODEV;
+ }
+
+ chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024;
+ if (chip->byte_len > 64 * 1024)
+ chip->flags |= EE_ADDR3;
+ else
+ 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];
+ }
+
+ chip->page_size = PAGE_SIZE;
+ return 0;
+}
+
static const struct of_device_id at25_of_match[] = {
- { .compatible = "atmel,at25",},
- { .compatible = "cypress,fm25",},
+ { .compatible = "atmel,at25" },
+ { .compatible = "cypress,fm25" },
{ }
};
MODULE_DEVICE_TABLE(of, at25_of_match);
static const struct spi_device_id at25_spi_ids[] = {
- { .name = "at25",},
- { .name = "fm25",},
+ { .name = "at25" },
+ { .name = "fm25" },
{ }
};
MODULE_DEVICE_TABLE(spi, at25_spi_ids);
@@ -378,31 +420,18 @@ static int at25_probe(struct spi_device *spi)
struct at25_data *at25 = NULL;
int err;
int sr;
- 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;
-
- at25 = devm_kzalloc(&spi->dev, sizeof(struct at25_data), GFP_KERNEL);
- if (!at25)
- return -ENOMEM;
-
- /* Chip description */
- if (spi->dev.platform_data) {
- memcpy(&at25->chip, spi->dev.platform_data, sizeof(at25->chip));
- } else if (!is_fram) {
- err = at25_fw_to_chip(&spi->dev, &at25->chip);
- if (err)
- return err;
- }
-
- /* Ping the chip ... the status register is pretty portable,
- * unlike probing manufacturer IDs. We do expect that system
+ struct spi_eeprom *pdata;
+ bool is_fram;
+
+ err = device_property_match_string(&spi->dev, "compatible", "cypress,fm25");
+ if (err >= 0)
+ is_fram = true;
+ else
+ is_fram = false;
+
+ /*
+ * 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!
*/
sr = spi_w8r8(spi, AT25_RDSR);
@@ -415,35 +444,17 @@ static int at25_probe(struct spi_device *spi)
at25->spi = spi;
spi_set_drvdata(spi, at25);
- 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;
- }
- at25->chip.byte_len = int_pow(2, id[7] - 0x21 + 4) * 1024;
-
- if (at25->chip.byte_len > 64 * 1024)
- at25->chip.flags |= EE_ADDR3;
+ /* Chip description */
+ pdata = dev_get_platdata(&spi->dev);
+ if (pdata) {
+ at25->chip = *pdata;
+ } else {
+ if (is_fram)
+ err = at25_fram_to_chip(&spi->dev, &at25->chip);
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));
+ err = at25_fw_to_chip(&spi->dev, &at25->chip);
+ if (err)
+ return err;
}
/* For now we only support 8/16/24 bit addressing */
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 19:49:25 +0000