migrate gateworks board support to the new at24 eeprom driver

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@13450 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 134 insertions, 0 deletions

diff --git a/target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch b/target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch
new file mode 100644
index 000000000..36a3e6912
--- /dev/null
+++ b/target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch
@@ -0,0 +1,134 @@
+Subject: [PATCH 2/3] I2C: at24: add kernel interface for reading/writing EEPROM
+Date: Monday 25 August 2008
+From: Kevin Hilman <khilman@deeprootsystems.com>
+To: davinci-linux-open-source@linux.davincidsp.com
+
+This patch adds an interface by which other kernel code can read/write
+detected EEPROM.
+
+The platform code registers a 'setup' callback with the
+at24_platform_data.  When the at24 driver detects an EEPROM, it fills
+out the read and write functions of at24_iface and calls the setup
+callback.  The platform code can then use the read/write functions in
+the at24_iface struct for reading and writing the EEPROM.
+
+Original idea, review and updates by David Brownell <david-b@pacbell.net>
+
+Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
+---
+ drivers/i2c/chips/at24.c |   42 +++++++++++++++++++++++++++++++++++-------
+ include/linux/i2c/at24.h |   10 ++++++++++
+ 2 files changed, 45 insertions(+), 7 deletions(-)
+
+--- a/drivers/i2c/chips/at24.c
++++ b/drivers/i2c/chips/at24.c
+@@ -53,6 +53,7 @@
+ 
+ struct at24_data {
+ 	struct at24_platform_data chip;
++	struct at24_iface iface;
+ 	bool use_smbus;
+ 
+ 	/*
+@@ -264,13 +265,6 @@ static ssize_t at24_bin_read(struct kobj
+ 
+ 
+ /*
+- * REVISIT: export at24_bin{read,write}() to let other kernel code use
+- * eeprom data. For example, it might hold a board's Ethernet address, or
+- * board-specific calibration data generated on the manufacturing floor.
+- */
+-
+-
+-/*
+  * Note that if the hardware write-protect pin is pulled high, the whole
+  * chip is normally write protected. But there are plenty of product
+  * variants here, including OTP fuses and partial chip protect.
+@@ -386,6 +380,30 @@ static ssize_t at24_bin_write(struct kob
+ 
+ /*-------------------------------------------------------------------------*/
+ 
++/*
++ * This lets other kernel code access the eeprom data. For example, it
++ * might hold a board's Ethernet address, or board-specific calibration
++ * data generated on the manufacturing floor.
++ */
++
++static ssize_t at24_iface_read(struct at24_iface *iface, char *buf,
++			      off_t offset, size_t count)
++{
++	struct at24_data *at24 = container_of(iface, struct at24_data, iface);
++
++	return at24_eeprom_read(at24, buf, offset, count);
++}
++
++static ssize_t at24_iface_write(struct at24_iface *iface, char *buf,
++			       off_t offset, size_t count)
++{
++	struct at24_data *at24 = container_of(iface, struct at24_data, iface);
++
++	return at24_eeprom_write(at24, buf, offset, count);
++}
++
++/*-------------------------------------------------------------------------*/
++
+ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
+ {
+ 	struct at24_platform_data chip;
+@@ -413,6 +431,9 @@ static int at24_probe(struct i2c_client 
+ 		 * is recommended anyhow.
+ 		 */
+ 		chip.page_size = 1;
++
++		chip.setup = NULL;
++		chip.context = NULL;
+ 	}
+ 
+ 	if (!is_power_of_2(chip.byte_len))
+@@ -449,6 +470,9 @@ static int at24_probe(struct i2c_client 
+ 		goto err_out;
+ 	}
+ 
++	at24->iface.read = at24_iface_read;
++	at24->iface.write = at24_iface_write;
++
+ 	mutex_init(&at24->lock);
+ 	at24->use_smbus = use_smbus;
+ 	at24->chip = chip;
+@@ -521,6 +545,10 @@ static int at24_probe(struct i2c_client 
+ 		at24->write_max,
+ 		use_smbus ? ", use_smbus" : "");
+ 
++	/* export data to kernel code */
++	if (chip.setup)
++		chip.setup(&at24->iface, chip.context);
++
+ 	return 0;
+ 
+ err_clients:
+--- a/include/linux/i2c/at24.h
++++ b/include/linux/i2c/at24.h
+@@ -15,6 +15,13 @@
+  * is bigger than what the chip actually supports!
+  */
+ 
++struct at24_iface {
++	ssize_t (*read)(struct at24_iface *, char *buf, off_t offset,
++			size_t count);
++	ssize_t (*write)(struct at24_iface *, char *buf, off_t offset,
++			 size_t count);
++};
++
+ struct at24_platform_data {
+ 	u32		byte_len;		/* size (sum of all addr) */
+ 	u16		page_size;		/* for writes */
+@@ -23,6 +30,9 @@ struct at24_platform_data {
+ #define AT24_FLAG_READONLY	0x40	/* sysfs-entry will be read-only */
+ #define AT24_FLAG_IRUGO		0x20	/* sysfs-entry will be world-readable */
+ #define AT24_FLAG_TAKE8ADDR	0x10	/* take always 8 addresses (24c00) */
++
++	int             (*setup)(struct at24_iface *, void *context);
++	void		*context;
+ };
+ 
+ #endif /* _LINUX_AT24_H */