Commit 668ba5e6 authored by Wolfram Sang's avatar Wolfram Sang
Browse files

Merge tag 'at24-updates-for-v5.10' of... 

Merge tag 'at24-updates-for-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into i2c/for-5.10

at24 updates for v5.10

- add support for masking sensitive data in VAIO EEPROMs
- set the nvmem TYPE to NVMEM_TYPE_EEPROM
- add support for the new 'label' property
- set the nvmem ID to NVMEM_DEVID_AUTO by default (for backward
  compatibility) or to NVMEM_DEVID_NONE if label is defined
parents 9b65b020 61f764c3

Documentation/devicetree/bindings/eeprom/at24.yaml

+3 −0
Original line number Diff line number Diff line
@@ -114,6 +114,9 @@ properties: 
          - const: renesas,r1ex24128

          - const: atmel,24c128



  label:

    description: Descriptive name of the EEPROM.



  reg:

    maxItems: 1

drivers/misc/eeprom/at24.c

+64 −7
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <linux/acpi.h>

#include <linux/bitops.h>

#include <linux/capability.h>

#include <linux/delay.h>

#include <linux/i2c.h>

#include <linux/init.h>
@@ -89,6 +90,7 @@ struct at24_data { 


	struct nvmem_device *nvmem;

	struct regulator *vcc_reg;

	void (*read_post)(unsigned int off, char *buf, size_t count);



	/*

	 * Some chips tie up multiple I2C addresses; dummy devices reserve
@@ -121,6 +123,7 @@ MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); 
struct at24_chip_data {

	u32 byte_len;

	u8 flags;

	void (*read_post)(unsigned int off, char *buf, size_t count);

};



#define AT24_CHIP_DATA(_name, _len, _flags)				\
@@ -128,6 +131,32 @@ struct at24_chip_data { 
		.byte_len = _len, .flags = _flags,			\

	}



#define AT24_CHIP_DATA_CB(_name, _len, _flags, _read_post)		\

	static const struct at24_chip_data _name = {			\

		.byte_len = _len, .flags = _flags,			\

		.read_post = _read_post,				\

	}



static void at24_read_post_vaio(unsigned int off, char *buf, size_t count)

{

	int i;



	if (capable(CAP_SYS_ADMIN))

		return;



	/*

	 * Hide VAIO private settings to regular users:

	 * - BIOS passwords: bytes 0x00 to 0x0f

	 * - UUID: bytes 0x10 to 0x1f

	 * - Serial number: 0xc0 to 0xdf

	 */

	for (i = 0; i < count; i++) {

		if ((off + i <= 0x1f) ||

		    (off + i >= 0xc0 && off + i <= 0xdf))

			buf[i] = 0;

	}

}



/* needs 8 addresses as A0-A2 are ignored */

AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR);

/* old variants can't be handled with this generic entry! */
@@ -144,6 +173,10 @@ AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, 
/* spd is a 24c02 in memory DIMMs */

AT24_CHIP_DATA(at24_data_spd, 2048 / 8,

	AT24_FLAG_READONLY | AT24_FLAG_IRUGO);

/* 24c02_vaio is a 24c02 on some Sony laptops */

AT24_CHIP_DATA_CB(at24_data_24c02_vaio, 2048 / 8,

	AT24_FLAG_READONLY | AT24_FLAG_IRUGO,

	at24_read_post_vaio);

AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0);

AT24_CHIP_DATA(at24_data_24cs04, 16,

	AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
@@ -177,6 +210,7 @@ static const struct i2c_device_id at24_ids[] = { 
	{ "24mac402",	(kernel_ulong_t)&at24_data_24mac402 },

	{ "24mac602",	(kernel_ulong_t)&at24_data_24mac602 },

	{ "spd",	(kernel_ulong_t)&at24_data_spd },

	{ "24c02-vaio",	(kernel_ulong_t)&at24_data_24c02_vaio },

	{ "24c04",	(kernel_ulong_t)&at24_data_24c04 },

	{ "24cs04",	(kernel_ulong_t)&at24_data_24cs04 },

	{ "24c08",	(kernel_ulong_t)&at24_data_24c08 },
@@ -388,7 +422,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count) 
	struct at24_data *at24;

	struct device *dev;

	char *buf = val;

	int ret;

	int i, ret;



	at24 = priv;

	dev = at24_base_client_dev(at24);
@@ -411,22 +445,22 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count) 
	 */

	mutex_lock(&at24->lock);



	while (count) {

		ret = at24_regmap_read(at24, buf, off, count);

	for (i = 0; count; i += ret, count -= ret) {

		ret = at24_regmap_read(at24, buf + i, off + i, count);

		if (ret < 0) {

			mutex_unlock(&at24->lock);

			pm_runtime_put(dev);

			return ret;

		}

		buf += ret;

		off += ret;

		count -= ret;

	}



	mutex_unlock(&at24->lock);



	pm_runtime_put(dev);



	if (unlikely(at24->read_post))

		at24->read_post(off, buf, i);



	return 0;

}
@@ -654,6 +688,7 @@ static int at24_probe(struct i2c_client *client) 
	at24->byte_len = byte_len;

	at24->page_size = page_size;

	at24->flags = flags;

	at24->read_post = cdata->read_post;

	at24->num_addresses = num_addresses;

	at24->offset_adj = at24_get_offset_adj(flags, byte_len);

	at24->client[0].client = client;
@@ -678,8 +713,30 @@ static int at24_probe(struct i2c_client *client) 
			return err;

	}



	/*

	 * If the 'label' property is not present for the AT24 EEPROM,

	 * then nvmem_config.id is initialised to NVMEM_DEVID_AUTO,

	 * and this will append the 'devid' to the name of the NVMEM

	 * device. This is purely legacy and the AT24 driver has always

	 * defaulted to this. However, if the 'label' property is

	 * present then this means that the name is specified by the

	 * firmware and this name should be used verbatim and so it is

	 * not necessary to append the 'devid'.

	 */

	if (device_property_present(dev, "label")) {

		nvmem_config.id = NVMEM_DEVID_NONE;

		err = device_property_read_string(dev, "label",

						  &nvmem_config.name);

		if (err)

			return err;

	} else {

		nvmem_config.id = NVMEM_DEVID_AUTO;

		nvmem_config.name = dev_name(dev);

	}



	nvmem_config.type = NVMEM_TYPE_EEPROM;

	nvmem_config.dev = dev;

	nvmem_config.id = NVMEM_DEVID_AUTO;

	nvmem_config.read_only = !writable;

	nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO);

	nvmem_config.owner = THIS_MODULE;

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