eeprom: at24: extend driver to plug into the NVMEM framework
Add a regmap for accessing the EEPROM, and then use that with the
NVMEM framework. Set the NVMEM config structure to enable backward, so
that the 'eeprom' file in sys is provided by the framework.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
index 04f2e1f..2493547 100644
--- a/drivers/misc/eeprom/Kconfig
+++ b/drivers/misc/eeprom/Kconfig
@@ -3,6 +3,8 @@
config EEPROM_AT24
tristate "I2C EEPROMs / RAMs / ROMs from most vendors"
depends on I2C && SYSFS
+ select REGMAP
+ select NVMEM
help
Enable this driver to get read/write support to most I2C EEPROMs
and compatible devices like FRAMs, SRAMs, ROMs etc. After you
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index d105c25..f15cda9 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -15,7 +15,6 @@
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mutex.h>
-#include <linux/sysfs.h>
#include <linux/mod_devicetable.h>
#include <linux/log2.h>
#include <linux/bitops.h>
@@ -23,6 +22,8 @@
#include <linux/of.h>
#include <linux/acpi.h>
#include <linux/i2c.h>
+#include <linux/nvmem-provider.h>
+#include <linux/regmap.h>
#include <linux/platform_data/at24.h>
/*
@@ -64,12 +65,15 @@
* but not from changes by other I2C masters.
*/
struct mutex lock;
- struct bin_attribute bin;
u8 *writebuf;
unsigned write_max;
unsigned num_addresses;
+ struct regmap_config regmap_config;
+ struct nvmem_config nvmem_config;
+ struct nvmem_device *nvmem;
+
/*
* Some chips tie up multiple I2C addresses; dummy devices reserve
* them for us, and we'll use them with SMBus calls.
@@ -283,17 +287,6 @@
return retval;
}
-static ssize_t at24_bin_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *attr,
- char *buf, loff_t off, size_t count)
-{
- struct at24_data *at24;
-
- at24 = dev_get_drvdata(kobj_to_dev(kobj));
- return at24_read(at24, buf, off, count);
-}
-
-
/*
* Note that if the hardware write-protect pin is pulled high, the whole
* chip is normally write protected. But there are plenty of product
@@ -414,16 +407,6 @@
return retval;
}
-static ssize_t at24_bin_write(struct file *filp, struct kobject *kobj,
- struct bin_attribute *attr,
- char *buf, loff_t off, size_t count)
-{
- struct at24_data *at24;
-
- at24 = dev_get_drvdata(kobj_to_dev(kobj));
- return at24_write(at24, buf, off, count);
-}
-
/*-------------------------------------------------------------------------*/
/*
@@ -450,6 +433,49 @@
/*-------------------------------------------------------------------------*/
+/*
+ * Provide a regmap interface, which is registered with the NVMEM
+ * framework
+*/
+static int at24_regmap_read(void *context, const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct at24_data *at24 = context;
+ off_t offset = *(u32 *)reg;
+ int err;
+
+ err = at24_read(at24, val, offset, val_size);
+ if (err)
+ return err;
+ return 0;
+}
+
+static int at24_regmap_write(void *context, const void *data, size_t count)
+{
+ struct at24_data *at24 = context;
+ const char *buf;
+ u32 offset;
+ size_t len;
+ int err;
+
+ memcpy(&offset, data, sizeof(offset));
+ buf = (const char *)data + sizeof(offset);
+ len = count - sizeof(offset);
+
+ err = at24_write(at24, buf, offset, len);
+ if (err)
+ return err;
+ return 0;
+}
+
+static const struct regmap_bus at24_regmap_bus = {
+ .read = at24_regmap_read,
+ .write = at24_regmap_write,
+ .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+/*-------------------------------------------------------------------------*/
+
#ifdef CONFIG_OF
static void at24_get_ofdata(struct i2c_client *client,
struct at24_platform_data *chip)
@@ -481,6 +507,7 @@
struct at24_data *at24;
int err;
unsigned i, num_addresses;
+ struct regmap *regmap;
if (client->dev.platform_data) {
chip = *(struct at24_platform_data *)client->dev.platform_data;
@@ -573,16 +600,6 @@
at24->chip = chip;
at24->num_addresses = num_addresses;
- /*
- * Export the EEPROM bytes through sysfs, since that's convenient.
- * By default, only root should see the data (maybe passwords etc)
- */
- sysfs_bin_attr_init(&at24->bin);
- at24->bin.attr.name = "eeprom";
- at24->bin.attr.mode = chip.flags & AT24_FLAG_IRUGO ? S_IRUGO : S_IRUSR;
- at24->bin.read = at24_bin_read;
- at24->bin.size = chip.byte_len;
-
at24->macc.read = at24_macc_read;
writable = !(chip.flags & AT24_FLAG_READONLY);
@@ -593,9 +610,6 @@
at24->macc.write = at24_macc_write;
- at24->bin.write = at24_bin_write;
- at24->bin.attr.mode |= S_IWUSR;
-
if (write_max > io_limit)
write_max = io_limit;
if (use_smbus && write_max > I2C_SMBUS_BLOCK_MAX)
@@ -627,14 +641,38 @@
}
}
- err = sysfs_create_bin_file(&client->dev.kobj, &at24->bin);
- if (err)
+ at24->regmap_config.reg_bits = 32;
+ at24->regmap_config.val_bits = 8;
+ at24->regmap_config.reg_stride = 1;
+ at24->regmap_config.max_register = chip.byte_len - 1;
+
+ regmap = devm_regmap_init(&client->dev, &at24_regmap_bus, at24,
+ &at24->regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(&client->dev, "regmap init failed\n");
+ err = PTR_ERR(regmap);
goto err_clients;
+ }
+
+ at24->nvmem_config.name = dev_name(&client->dev);
+ at24->nvmem_config.dev = &client->dev;
+ at24->nvmem_config.read_only = !writable;
+ at24->nvmem_config.root_only = true;
+ at24->nvmem_config.owner = THIS_MODULE;
+ at24->nvmem_config.compat = true;
+ at24->nvmem_config.base_dev = &client->dev;
+
+ at24->nvmem = nvmem_register(&at24->nvmem_config);
+
+ if (IS_ERR(at24->nvmem)) {
+ err = PTR_ERR(at24->nvmem);
+ goto err_clients;
+ }
i2c_set_clientdata(client, at24);
- dev_info(&client->dev, "%zu byte %s EEPROM, %s, %u bytes/write\n",
- at24->bin.size, client->name,
+ dev_info(&client->dev, "%u byte %s EEPROM, %s, %u bytes/write\n",
+ chip.byte_len, client->name,
writable ? "writable" : "read-only", at24->write_max);
if (use_smbus == I2C_SMBUS_WORD_DATA ||
use_smbus == I2C_SMBUS_BYTE_DATA) {
@@ -663,7 +701,8 @@
int i;
at24 = i2c_get_clientdata(client);
- sysfs_remove_bin_file(&client->dev.kobj, &at24->bin);
+
+ nvmem_unregister(at24->nvmem);
for (i = 1; i < at24->num_addresses; i++)
i2c_unregister_device(at24->client[i]);