Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1271024 > unrolled thread

[RESEND PATCH v2 0/9] eeprom: at24: at24cs series serial number read

Back to article view | Back to linux.kernel

Contents

  [RESEND PATCH v2 0/9] eeprom: at24: at24cs series serial number read Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2015-11-17 11:00 +0100
    [RESEND PATCH v2 2/9] eeprom: at24: new flag in platform_data Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2015-11-17 11:00 +0100
    [RESEND PATCH v2 5/9] eeprom: at24: export the serial number through sysfs Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2015-11-17 11:00 +0100
    [RESEND PATCH v2 8/9] eeprom: at24: remove a reduntant if Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2015-11-17 11:00 +0100
    [RESEND PATCH v2 6/9] eeprom: at24: improve the device_id table readability Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2015-11-17 11:00 +0100
    [RESEND PATCH v2 3/9] eeprom: at24: tie up an additional address for at24cs series Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2015-11-17 11:00 +0100

#1271024 — [RESEND PATCH v2 0/9] eeprom: at24: at24cs series serial number read

Chips from the at24cs EEPROM series have an additional read-only memory area
containing a factory pre-programmed serial number. In order to access it, a
dummy write must be executed before reading the serial number bytes.

This series adds support for reading the serial number through a sysfs
attribute.

While we're at it: some of the patches contain readability tweaks and code
organization fixes.

Tested with at24cs64 and at24cs02 chips (for both 16 and 8 bit address
pointers).

(rebased against 4.4-rc1)

v2:
- protect the serial number read with a mutex

v1: https://lkml.org/lkml/2015/10/20/162

Bartosz Golaszewski (9):
  eeprom: at24: platform_data: use BIT() macro
  eeprom: at24: new flag in platform_data
  eeprom: at24: tie up an additional address for at24cs series
  eeprom: at24: support reading of the serial number
  eeprom: at24: export the serial number through sysfs
  eeprom: at24: improve the device_id table readability
  eeprom: at24: add the at24cs series to the list of supported devices
  eeprom: at24: remove a reduntant if
  eeprom: at24: readability tweaks

 drivers/misc/eeprom/at24.c         | 187 +++++++++++++++++++++++++++++++------
 include/linux/platform_data/at24.h |   9 +-
 2 files changed, 166 insertions(+), 30 deletions(-)

-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1271025 — [RESEND PATCH v2 2/9] eeprom: at24: new flag in platform_data

In preparation for supporting the at24cs EEPROM series add a new flag to
platform data. When set, it should tell the driver that the chip has an
additional read-only memory area that holds a factory pre-programmed serial
number.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 include/linux/platform_data/at24.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/platform_data/at24.h b/include/linux/platform_data/at24.h
index 8d90f52..5686f91 100644
--- a/include/linux/platform_data/at24.h
+++ b/include/linux/platform_data/at24.h
@@ -47,6 +47,7 @@ struct at24_platform_data {
 #define AT24_FLAG_READONLY	BIT(6)	/* sysfs-entry will be read-only */
 #define AT24_FLAG_IRUGO		BIT(5)	/* sysfs-entry will be world-readable */
 #define AT24_FLAG_TAKE8ADDR	BIT(4)	/* take always 8 addresses (24c00) */
+#define AT24_FLAG_SERIAL	BIT(3)	/* factory-programmed serial number */
 
 	void		(*setup)(struct memory_accessor *, void *context);
 	void		*context;
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1271027 — [RESEND PATCH v2 5/9] eeprom: at24: export the serial number through sysfs

The at24 driver is now capable of reading the serial number from at24cs
EEPROM chips. Export the serial number through sysfs.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/misc/eeprom/at24.c | 44 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 40 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 6182f47..65fca1e 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -65,6 +65,7 @@ struct at24_data {
 	 */
 	struct mutex lock;
 	struct bin_attribute bin;
+	struct bin_attribute *bin_serial;
 
 	u8 *writebuf;
 	unsigned write_max;
@@ -103,6 +104,7 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
 
 #define AT24_BITMASK(x) (BIT(x) - 1)
 
+#define AT24CS_SERIAL_SIZE 16
 #define AT24CS_SERIAL_ADDR(addr) (addr + 0x08)
 
 /* create non-zero magic value for given eeprom parameters */
@@ -163,10 +165,8 @@ static struct i2c_client *at24_translate_offset(struct at24_data *at24,
 	return at24->client[i];
 }
 
-static int __attribute__((unused)) at24cs_eeprom_serial_read(
-						struct at24_data *at24,
-						char *buf, unsigned offset,
-						size_t count)
+static int at24cs_eeprom_serial_read(struct at24_data *at24, char *buf,
+				     unsigned offset, size_t count)
 {
 	unsigned long timeout, read_time;
 	struct i2c_client *client;
@@ -234,6 +234,16 @@ static int __attribute__((unused)) at24cs_eeprom_serial_read(
 	return -ETIMEDOUT;
 }
 
+static ssize_t at24cs_bin_serial_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(container_of(kobj, struct device, kobj));
+	return at24cs_eeprom_serial_read(at24, buf, off, count);
+}
+
 static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf,
 		unsigned offset, size_t count)
 {
@@ -658,6 +668,30 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	at24->bin.read = at24_bin_read;
 	at24->bin.size = chip.byte_len;
 
+	if (at24->chip.flags & AT24_FLAG_SERIAL) {
+		/*
+		 * For EEPROMs containing the serial number export an
+		 * additional file allowing allowing convenvient access
+		 * to it from user-space.
+		 */
+		at24->bin_serial = devm_kzalloc(&client->dev,
+						sizeof(struct bin_attribute),
+						GFP_KERNEL);
+		if (!at24->bin_serial)
+			return -ENOMEM;
+
+		sysfs_bin_attr_init(at24->bin_serial);
+		at24->bin_serial->attr.name = "serial";
+		at24->bin_serial->attr.mode = S_IRUSR;
+		at24->bin_serial->read = at24cs_bin_serial_read;
+		at24->bin_serial->size = AT24CS_SERIAL_SIZE;
+
+		err = sysfs_create_bin_file(&client->dev.kobj,
+					    at24->bin_serial);
+		if (err)
+			goto err_clients;
+	}
+
 	at24->macc.read = at24_macc_read;
 
 	writable = !(chip.flags & AT24_FLAG_READONLY);
@@ -757,6 +791,8 @@ static int at24_remove(struct i2c_client *client)
 
 	at24 = i2c_get_clientdata(client);
 	sysfs_remove_bin_file(&client->dev.kobj, &at24->bin);
+	if (at24->bin_serial)
+		sysfs_remove_bin_file(&client->dev.kobj, at24->bin_serial);
 
 	for (i = 1; i < at24->num_addresses; i++)
 		i2c_unregister_device(at24->client[i]);
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1271031 — [RESEND PATCH v2 8/9] eeprom: at24: remove a reduntant if

It seems as if the second check for I2C_FUNC_I2C functionality had been
introduced accidentally during a merge. Tt's reduntant, so remove it.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/misc/eeprom/at24.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 6e28b02..1288193 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -634,10 +634,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		} else {
 			return -EPFNOSUPPORT;
 		}
-	}
 
-	/* Use I2C operations unless we're stuck with SMBus extensions. */
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		if (i2c_check_functionality(client->adapter,
 				I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
 			use_smbus_write = I2C_SMBUS_I2C_BLOCK_DATA;
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1271032 — [RESEND PATCH v2 6/9] eeprom: at24: improve the device_id table readability

Improve the readability of the device table by separating columns with
tabs.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/misc/eeprom/at24.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 65fca1e..d474b6d 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -114,23 +114,23 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
 
 static const struct i2c_device_id at24_ids[] = {
 	/* needs 8 addresses as A0-A2 are ignored */
-	{ "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) },
+	{ "24c00",	AT24_DEVICE_MAGIC(128 / 8,	AT24_FLAG_TAKE8ADDR) },
 	/* old variants can't be handled with this generic entry! */
-	{ "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) },
-	{ "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) },
+	{ "24c01",	AT24_DEVICE_MAGIC(1024 / 8,	0) },
+	{ "24c02",	AT24_DEVICE_MAGIC(2048 / 8,	0) },
 	/* spd is a 24c02 in memory DIMMs */
-	{ "spd", AT24_DEVICE_MAGIC(2048 / 8,
-		AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
-	{ "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) },
+	{ "spd",	AT24_DEVICE_MAGIC(2048 / 8,
+				AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
+	{ "24c04",	AT24_DEVICE_MAGIC(4096 / 8,	0) },
 	/* 24rf08 quirk is handled at i2c-core */
-	{ "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) },
-	{ "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) },
-	{ "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) },
-	{ "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) },
-	{ "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) },
-	{ "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) },
-	{ "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) },
-	{ "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) },
+	{ "24c08",	AT24_DEVICE_MAGIC(8192 / 8,	0) },
+	{ "24c16",	AT24_DEVICE_MAGIC(16384 / 8,	0) },
+	{ "24c32",	AT24_DEVICE_MAGIC(32768 / 8,	AT24_FLAG_ADDR16) },
+	{ "24c64",	AT24_DEVICE_MAGIC(65536 / 8,	AT24_FLAG_ADDR16) },
+	{ "24c128",	AT24_DEVICE_MAGIC(131072 / 8,	AT24_FLAG_ADDR16) },
+	{ "24c256",	AT24_DEVICE_MAGIC(262144 / 8,	AT24_FLAG_ADDR16) },
+	{ "24c512",	AT24_DEVICE_MAGIC(524288 / 8,	AT24_FLAG_ADDR16) },
+	{ "24c1024",	AT24_DEVICE_MAGIC(1048576 / 8,	AT24_FLAG_ADDR16) },
 	{ "at24", 0 },
 	{ /* END OF LIST */ }
 };
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1271034 — [RESEND PATCH v2 3/9] eeprom: at24: tie up an additional address for at24cs series

The at24cs series EEPROM chips have an additional read-only memory area,
that is visible on a different i2c slave address. Tie it up with a dummy
device.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/misc/eeprom/at24.c | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 5d7c090..08cc327 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -103,6 +103,8 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
 
 #define AT24_BITMASK(x) (BIT(x) - 1)
 
+#define AT24CS_SERIAL_ADDR(addr) (addr + 0x08)
+
 /* create non-zero magic value for given eeprom parameters */
 #define AT24_DEVICE_MAGIC(_len, _flags) 		\
 	((1 << AT24_SIZE_FLAGS | (_flags)) 		\
@@ -558,6 +560,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	if (chip.flags & AT24_FLAG_TAKE8ADDR)
 		num_addresses = 8;
+	else if (chip.flags & AT24_FLAG_SERIAL)
+		num_addresses = 2;
 	else
 		num_addresses =	DIV_ROUND_UP(chip.byte_len,
 			(chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256);
@@ -616,12 +620,30 @@ 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,
+	if (at24->chip.flags & AT24_FLAG_TAKE8ADDR) {
+		for (i = 1; i < num_addresses; i++) {
+			at24->client[i] = i2c_new_dummy(client->adapter,
+							client->addr + i);
+			if (!at24->client[i]) {
+				dev_err(&client->dev,
+					"address 0x%02x unavailable\n",
 					client->addr + i);
-		if (!at24->client[i]) {
+				err = -EADDRINUSE;
+				goto err_clients;
+			}
+		}
+	}
+
+	/*
+	 * at24cs series tie up an additional address for the memory area
+	 * contining the serial number
+	 */
+	if (at24->chip.flags & AT24_FLAG_SERIAL) {
+		at24->client[1] = i2c_new_dummy(client->adapter,
+					AT24CS_SERIAL_ADDR(client->addr));
+		if (!at24->client[1]) {
 			dev_err(&client->dev, "address 0x%02x unavailable\n",
-					client->addr + i);
+				AT24CS_SERIAL_ADDR(client->addr));
 			err = -EADDRINUSE;
 			goto err_clients;
 		}
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web