Commit 5c015258 authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Bartosz Golaszewski
Browse files

eeprom: at24: add basic regmap_i2c support 



This patch adds basic regmap support to be used by subsequent
patches of this series.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
parent 30a7acd5

drivers/misc/eeprom/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ config EEPROM_AT24 
	tristate "I2C EEPROMs / RAMs / ROMs from most vendors"

	depends on I2C && SYSFS

	select NVMEM

	select REGMAP_I2C

	help

	  Enable this driver to get read/write support to most I2C EEPROMs

	  and compatible devices like FRAMs, SRAMs, ROMs etc. After you

drivers/misc/eeprom/at24.c

+44 −13
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/acpi.h>

#include <linux/i2c.h>

#include <linux/nvmem-provider.h>

#include <linux/regmap.h>

#include <linux/platform_data/at24.h>

#include <linux/pm_runtime.h>
@@ -55,6 +56,11 @@ 
 * which won't work on pure SMBus systems.

 */



struct at24_client {

	struct i2c_client *client;

	struct regmap *regmap;

};



struct at24_data {

	struct at24_platform_data chip;

	int use_smbus;
@@ -81,7 +87,7 @@ struct at24_data { 
	 * Some chips tie up multiple I2C addresses; dummy devices reserve

	 * them for us, and we'll use them with SMBus calls.

	 */

	struct i2c_client *client[];

	struct at24_client client[];

};



/*
@@ -274,7 +280,7 @@ static struct i2c_client *at24_translate_offset(struct at24_data *at24, 
		*offset &= 0xff;

	}



	return at24->client[i];

	return at24->client[i].client;

}



static ssize_t at24_eeprom_read_smbus(struct at24_data *at24, char *buf,
@@ -562,7 +568,7 @@ static ssize_t at24_eeprom_write_i2c(struct at24_data *at24, const char *buf, 
static int at24_read(void *priv, unsigned int off, void *val, size_t count)

{

	struct at24_data *at24 = priv;

	struct device *dev = &at24->client[0]->dev;

	struct device *dev = &at24->client[0].client->dev;

	char *buf = val;

	int ret;
@@ -608,7 +614,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count) 
static int at24_write(void *priv, unsigned int off, void *val, size_t count)

{

	struct at24_data *at24 = priv;

	struct device *dev = &at24->client[0]->dev;

	struct device *dev = &at24->client[0].client->dev;

	char *buf = val;

	int ret;
@@ -676,6 +682,16 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip) 
	}

}



static const struct regmap_config regmap_config_8 = {

	.reg_bits = 8,

	.val_bits = 8,

};



static const struct regmap_config regmap_config_16 = {

	.reg_bits = 16,

	.val_bits = 8,

};



static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)

{

	struct at24_platform_data chip;
@@ -686,6 +702,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) 
	struct at24_data *at24;

	int err;

	unsigned i, num_addresses;

	const struct regmap_config *config;

	u8 test_byte;



	if (client->dev.platform_data) {
@@ -777,8 +794,13 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) 
		num_addresses =	DIV_ROUND_UP(chip.byte_len,

			(chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256);



	if (chip.flags & AT24_FLAG_ADDR16)

		config = &regmap_config_16;

	else

		config = &regmap_config_8;



	at24 = devm_kzalloc(&client->dev, sizeof(struct at24_data) +

		num_addresses * sizeof(struct i2c_client *), GFP_KERNEL);

		num_addresses * sizeof(struct at24_client), GFP_KERNEL);

	if (!at24)

		return -ENOMEM;
@@ -788,6 +810,11 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) 
	at24->chip = chip;

	at24->num_addresses = num_addresses;



	at24->client[0].client = client;

	at24->client[0].regmap = devm_regmap_init_i2c(client, config);

	if (IS_ERR(at24->client[0].regmap))

		return PTR_ERR(at24->client[0].regmap);



	if ((chip.flags & AT24_FLAG_SERIAL) && (chip.flags & AT24_FLAG_MAC)) {

		dev_err(&client->dev,

			"invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC.");
@@ -835,18 +862,22 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) 
		}

	}



	at24->client[0] = client;



	/* use dummy devices for multiple-address chips */

	for (i = 1; i < num_addresses; i++) {

		at24->client[i] = i2c_new_dummy(client->adapter,

		at24->client[i].client = i2c_new_dummy(client->adapter,

						       client->addr + i);

		if (!at24->client[i]) {

		if (!at24->client[i].client) {

			dev_err(&client->dev, "address 0x%02x unavailable\n",

					client->addr + i);

			err = -EADDRINUSE;

			goto err_clients;

		}

		at24->client[i].regmap = devm_regmap_init_i2c(

					at24->client[i].client, config);

		if (IS_ERR(at24->client[i].regmap)) {

			err = PTR_ERR(at24->client[i].regmap);

			goto err_clients;

		}

	}



	i2c_set_clientdata(client, at24);
@@ -905,8 +936,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) 


err_clients:

	for (i = 1; i < num_addresses; i++)

		if (at24->client[i])

			i2c_unregister_device(at24->client[i]);

		if (at24->client[i].client)

			i2c_unregister_device(at24->client[i].client);



	pm_runtime_disable(&client->dev);
@@ -923,7 +954,7 @@ static int at24_remove(struct i2c_client *client) 
	nvmem_unregister(at24->nvmem);



	for (i = 1; i < at24->num_addresses; i++)

		i2c_unregister_device(at24->client[i]);

		i2c_unregister_device(at24->client[i].client);



	pm_runtime_disable(&client->dev);

	pm_runtime_set_suspended(&client->dev);