eeprom: at24: remove nvmem regmap dependency

This patch moves to nvmem support in the driver to use callback instead
of regmap.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 22 insertions, 82 deletions

diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
index cfc493c2e30a..2d70464e8c8d 100644
--- a/drivers/misc/eeprom/Kconfig
+++ b/drivers/misc/eeprom/Kconfig
@@ -3,7 +3,6 @@ menu "EEPROM support"
 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
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 089d6943f68a..de550a605f7d 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -23,7 +23,6 @@
 #include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/nvmem-provider.h>
-#include <linux/regmap.h>
 #include <linux/platform_data/at24.h>
 
 /*
@@ -69,7 +68,6 @@ struct at24_data {
         unsigned write_max;
         unsigned num_addresses;
 
-        struct regmap_config regmap_config;
         struct nvmem_config nvmem_config;
         struct nvmem_device *nvmem;
 
@@ -252,10 +250,10 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf,
         return -ETIMEDOUT;
 }
 
-static ssize_t at24_read(struct at24_data *at24,
-                char *buf, loff_t off, size_t count)
+static int at24_read(void *priv, unsigned int off, void *val, size_t count)
 {
-        ssize_t retval = 0;
+        struct at24_data *at24 = priv;
+        char *buf = val;
 
         if (unlikely(!count))
                 return count;
@@ -267,23 +265,21 @@ static ssize_t at24_read(struct at24_data *at24,
         mutex_lock(&at24->lock);
 
         while (count) {
-                ssize_t status;
+                int     status;
 
                 status = at24_eeprom_read(at24, buf, off, count);
-                if (status <= 0) {
-                        if (retval == 0)
-                                retval = status;
-                        break;
+                if (status < 0) {
+                        mutex_unlock(&at24->lock);
+                        return status;
                 }
                 buf += status;
                 off += status;
                 count -= status;
-                retval += status;
         }
 
         mutex_unlock(&at24->lock);
 
-        return retval;
+        return 0;
 }
 
 /*
@@ -372,13 +368,13 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
         return -ETIMEDOUT;
 }
 
-static ssize_t at24_write(struct at24_data *at24, const char *buf, loff_t off,
-                          size_t count)
+static int at24_write(void *priv, unsigned int off, void *val, size_t count)
 {
-        ssize_t retval = 0;
+        struct at24_data *at24 = priv;
+        char *buf = val;
 
         if (unlikely(!count))
-                return count;
+                return -EINVAL;
 
         /*
          * Write data to chip, protecting against concurrent updates
@@ -387,70 +383,23 @@ static ssize_t at24_write(struct at24_data *at24, const char *buf, loff_t off,
         mutex_lock(&at24->lock);
 
         while (count) {
-                ssize_t status;
+                int status;
 
                 status = at24_eeprom_write(at24, buf, off, count);
-                if (status <= 0) {
-                        if (retval == 0)
-                                retval = status;
-                        break;
+                if (status < 0) {
+                        mutex_unlock(&at24->lock);
+                        return status;
                 }
                 buf += status;
                 off += status;
                 count -= status;
-                retval += status;
         }
 
         mutex_unlock(&at24->lock);
 
-        return retval;
-}
-
-/*-------------------------------------------------------------------------*/
-
-/*
- * 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)
@@ -482,7 +431,6 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
         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;
@@ -612,19 +560,6 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
                 }
         }
 
-        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;
@@ -632,6 +567,12 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
         at24->nvmem_config.owner = THIS_MODULE;
         at24->nvmem_config.compat = true;
         at24->nvmem_config.base_dev = &client->dev;
+        at24->nvmem_config.reg_read = at24_read;
+        at24->nvmem_config.reg_write = at24_write;
+        at24->nvmem_config.priv = at24;
+        at24->nvmem_config.stride = 4;
+        at24->nvmem_config.word_size = 1;
+        at24->nvmem_config.size = chip.byte_len;
 
         at24->nvmem = nvmem_register(&at24->nvmem_config);