Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6 (278429cf) · Commits · 戴 / test

Documentation/i2c/busses/i2c-viapro

+6 −2

Original line number	Original line	Diff line number	Diff line
	@@ -16,6 +16,9 @@ Supported adapters:
	* VIA Technologies, Inc. CX700		* VIA Technologies, Inc. CX700
	Datasheet: available on request and under NDA from VIA		Datasheet: available on request and under NDA from VIA

			* VIA Technologies, Inc. VX800/VX820
			Datasheet: available on http://linux.via.com.tw

	Authors:		Authors:
	Kyösti Mälkki <kmalkki@cc.hut.fi>,		Kyösti Mälkki <kmalkki@cc.hut.fi>,
	Mark D. Studebaker <mdsxyz123@yahoo.com>,		Mark D. Studebaker <mdsxyz123@yahoo.com>,
	@@ -49,6 +52,7 @@ Your lspci -n listing must show one of these :
	device 1106:3372 (VT8237S)		device 1106:3372 (VT8237S)
	device 1106:3287 (VT8251)		device 1106:3287 (VT8251)
	device 1106:8324 (CX700)		device 1106:8324 (CX700)
			device 1106:8353 (VX800/VX820)

	If none of these show up, you should look in the BIOS for settings like		If none of these show up, you should look in the BIOS for settings like
	enable ACPI / SMBus or even USB.		enable ACPI / SMBus or even USB.
	@@ -57,5 +61,5 @@ Except for the oldest chips (VT82C596A/B, VT82C686A and most probably
	VT8231), this driver supports I2C block transactions. Such transactions		VT8231), this driver supports I2C block transactions. Such transactions
	are mainly useful to read from and write to EEPROMs.		are mainly useful to read from and write to EEPROMs.

	The CX700 additionally appears to support SMBus PEC, although this driver		The CX700/VX800/VX820 additionally appears to support SMBus PEC, although
	doesn't implement it yet.		this driver doesn't implement it yet.

Documentation/i2c/dev-interface

+85 −25

Original line number	Original line	Diff line number	Diff line
	@@ -4,6 +4,10 @@ the /dev interface. You need to load module i2c-dev for this.

	Each registered i2c adapter gets a number, counting from 0. You can		Each registered i2c adapter gets a number, counting from 0. You can
	examine /sys/class/i2c-dev/ to see what number corresponds to which adapter.		examine /sys/class/i2c-dev/ to see what number corresponds to which adapter.
			Alternatively, you can run "i2cdetect -l" to obtain a formated list of all
			i2c adapters present on your system at a given time. i2cdetect is part of
			the i2c-tools package.

	I2C device files are character device files with major device number 89		I2C device files are character device files with major device number 89
	and a minor device number corresponding to the number assigned as		and a minor device number corresponding to the number assigned as
	explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,		explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,
	@@ -17,29 +21,33 @@ So let's say you want to access an i2c adapter from a C program. The
	first thing to do is "#include <linux/i2c-dev.h>". Please note that		first thing to do is "#include <linux/i2c-dev.h>". Please note that
	there are two files named "i2c-dev.h" out there, one is distributed		there are two files named "i2c-dev.h" out there, one is distributed
	with the Linux kernel and is meant to be included from kernel		with the Linux kernel and is meant to be included from kernel
	driver code, the other one is distributed with lm_sensors and is		driver code, the other one is distributed with i2c-tools and is
	meant to be included from user-space programs. You obviously want		meant to be included from user-space programs. You obviously want
	the second one here.		the second one here.

	Now, you have to decide which adapter you want to access. You should		Now, you have to decide which adapter you want to access. You should
	inspect /sys/class/i2c-dev/ to decide this. Adapter numbers are assigned		inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this.
	somewhat dynamically, so you can not even assume /dev/i2c-0 is the		Adapter numbers are assigned somewhat dynamically, so you can not
	first adapter.		assume much about them. They can even change from one boot to the next.

	Next thing, open the device file, as follows:		Next thing, open the device file, as follows:

	int file;		int file;
	int adapter_nr = 2; /* probably dynamically determined */		int adapter_nr = 2; /* probably dynamically determined */
	char filename[20];		char filename[20];

	sprintf(filename,"/dev/i2c-%d",adapter_nr);		snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
	if ((file = open(filename,O_RDWR)) < 0) {		file = open(filename, O_RDWR);
			if (file < 0) {
	/* ERROR HANDLING; you can check errno to see what went wrong */		/* ERROR HANDLING; you can check errno to see what went wrong */
	exit(1);		exit(1);
	}		}

	When you have opened the device, you must specify with what device		When you have opened the device, you must specify with what device
	address you want to communicate:		address you want to communicate:

	int addr = 0x40; /* The I2C address */		int addr = 0x40; /* The I2C address */

	if (ioctl(file, I2C_SLAVE, addr) < 0) {		if (ioctl(file, I2C_SLAVE, addr) < 0) {
	/* ERROR HANDLING; you can check errno to see what went wrong */		/* ERROR HANDLING; you can check errno to see what went wrong */
	exit(1);		exit(1);
	@@ -48,9 +56,11 @@ address you want to communicate:
	Well, you are all set up now. You can now use SMBus commands or plain		Well, you are all set up now. You can now use SMBus commands or plain
	I2C to communicate with your device. SMBus commands are preferred if		I2C to communicate with your device. SMBus commands are preferred if
	the device supports them. Both are illustrated below.		the device supports them. Both are illustrated below.

	__u8 register = 0x10; /* Device register to access */		__u8 register = 0x10; /* Device register to access */
	__s32 res;		__s32 res;
	char buf[10];		char buf[10];

	/* Using SMBus commands */		/* Using SMBus commands */
	res = i2c_smbus_read_word_data(file, register);		res = i2c_smbus_read_word_data(file, register);
	if (res < 0) {		if (res < 0) {
	@@ -58,6 +68,7 @@ the device supports them. Both are illustrated below.
	} else {		} else {
	/* res contains the read word */		/* res contains the read word */
	}		}

	/* Using I2C Write, equivalent of		/* Using I2C Write, equivalent of
	i2c_smbus_write_word_data(file, register, 0x6543) */		i2c_smbus_write_word_data(file, register, 0x6543) */
	buf[0] = register;		buf[0] = register;
	@@ -66,6 +77,7 @@ the device supports them. Both are illustrated below.
	if (write(file, buf, 3) ! =3) {		if (write(file, buf, 3) ! =3) {
	/* ERROR HANDLING: i2c transaction failed */		/* ERROR HANDLING: i2c transaction failed */
	}		}

	/* Using I2C Read, equivalent of i2c_smbus_read_byte(file) */		/* Using I2C Read, equivalent of i2c_smbus_read_byte(file) */
	if (read(file, buf, 1) != 1) {		if (read(file, buf, 1) != 1) {
	/* ERROR HANDLING: i2c transaction failed */		/* ERROR HANDLING: i2c transaction failed */
	@@ -73,6 +85,12 @@ the device supports them. Both are illustrated below.
	/* buf[0] contains the read byte */		/* buf[0] contains the read byte */
	}		}

			Note that only a subset of the I2C and SMBus protocols can be achieved by
			the means of read() and write() calls. In particular, so-called combined
			transactions (mixing read and write messages in the same transaction)
			aren't supported. For this reason, this interface is almost never used by
			user-space programs.

	IMPORTANT: because of the use of inline functions, you have to use		IMPORTANT: because of the use of inline functions, you have to use
	'-O' or some variation when you compile your program!		'-O' or some variation when you compile your program!

	@@ -80,8 +98,7 @@ IMPORTANT: because of the use of inline functions, you have to use
	Full interface description		Full interface description
	==========================		==========================

	The following IOCTLs are defined and fully supported		The following IOCTLs are defined:
	(see also i2c-dev.h):

	ioctl(file, I2C_SLAVE, long addr)		ioctl(file, I2C_SLAVE, long addr)
	Change slave address. The address is passed in the 7 lower bits of the		Change slave address. The address is passed in the 7 lower bits of the
	@@ -104,7 +121,6 @@ ioctl(file,I2C_FUNCS,unsigned long *funcs)
	Gets the adapter functionality and puts it in *funcs.		Gets the adapter functionality and puts it in *funcs.

	ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)		ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)

	Do combined read/write transaction without stop in between.		Do combined read/write transaction without stop in between.
	Only valid if the adapter has I2C_FUNC_I2C. The argument is		Only valid if the adapter has I2C_FUNC_I2C. The argument is
	a pointer to a		a pointer to a
	@@ -120,9 +136,8 @@ ioctl(file,I2C_RDWR,struct i2c_rdwr_ioctl_data *msgset)
	The slave address and whether to use ten bit address mode has to be		The slave address and whether to use ten bit address mode has to be
	set in each message, overriding the values set with the above ioctl's.		set in each message, overriding the values set with the above ioctl's.

			ioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args)
	Other values are NOT supported at this moment, except for I2C_SMBUS,		Not meant to be called directly; instead, use the access functions
	which you should never directly call; instead, use the access functions
	below.		below.

	You can do plain i2c transactions by using read(2) and write(2) calls.		You can do plain i2c transactions by using read(2) and write(2) calls.
	@@ -148,7 +163,52 @@ what happened. The 'write' transactions return 0 on success; the
	returns the number of values read. The block buffers need not be longer		returns the number of values read. The block buffers need not be longer
	than 32 bytes.		than 32 bytes.

	The above functions are all macros, that resolve to calls to the		The above functions are all inline functions, that resolve to calls to
	i2c_smbus_access function, that on its turn calls a specific ioctl		the i2c_smbus_access function, that on its turn calls a specific ioctl
	with the data in a specific format. Read the source code if you		with the data in a specific format. Read the source code if you
	want to know what happens behind the screens.		want to know what happens behind the screens.


			Implementation details
			======================

			For the interested, here's the code flow which happens inside the kernel
			when you use the /dev interface to I2C:

			1* Your program opens /dev/i2c-N and calls ioctl() on it, as described in
			section "C example" above.

			2* These open() and ioctl() calls are handled by the i2c-dev kernel
			driver: see i2c-dev.c:i2cdev_open() and i2c-dev.c:i2cdev_ioctl(),
			respectively. You can think of i2c-dev as a generic I2C chip driver
			that can be programmed from user-space.

			3* Some ioctl() calls are for administrative tasks and are handled by
			i2c-dev directly. Examples include I2C_SLAVE (set the address of the
			device you want to access) and I2C_PEC (enable or disable SMBus error
			checking on future transactions.)

			4* Other ioctl() calls are converted to in-kernel function calls by
			i2c-dev. Examples include I2C_FUNCS, which queries the I2C adapter
			functionality using i2c.h:i2c_get_functionality(), and I2C_SMBUS, which
			performs an SMBus transaction using i2c-core.c:i2c_smbus_xfer().

			The i2c-dev driver is responsible for checking all the parameters that
			come from user-space for validity. After this point, there is no
			difference between these calls that came from user-space through i2c-dev
			and calls that would have been performed by kernel I2C chip drivers
			directly. This means that I2C bus drivers don't need to implement
			anything special to support access from user-space.

			5* These i2c-core.c/i2c.h functions are wrappers to the actual
			implementation of your I2C bus driver. Each adapter must declare
			callback functions implementing these standard calls.
			i2c.h:i2c_get_functionality() calls i2c_adapter.algo->functionality(),
			while i2c-core.c:i2c_smbus_xfer() calls either
			adapter.algo->smbus_xfer() if it is implemented, or if not,
			i2c-core.c:i2c_smbus_xfer_emulated() which in turn calls
			i2c_adapter.algo->master_xfer().

			After your I2C bus driver has processed these requests, execution runs
			up the call chain, with almost no processing done, except by i2c-dev to
			package the returned data, if any, in suitable format for the ioctl.

Documentation/i2c/smbus-protocol

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -109,8 +109,8 @@ specified through the Comm byte.
	S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P		S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P


	SMBus Process Call		SMBus Process Call: i2c_smbus_process_call()
	==================		=============================================

	This command selects a device register (through the Comm byte), sends		This command selects a device register (through the Comm byte), sends
	16 bits of data to it, and reads 16 bits of data in return.		16 bits of data to it, and reads 16 bits of data in return.

Documentation/i2c/writing-clients

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -606,6 +606,8 @@ SMBus communication
	extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);		extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);
	extern s32 i2c_smbus_write_word_data(struct i2c_client * client,		extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
	u8 command, u16 value);		u8 command, u16 value);
			extern s32 i2c_smbus_process_call(struct i2c_client *client,
			u8 command, u16 value);
	extern s32 i2c_smbus_read_block_data(struct i2c_client * client,		extern s32 i2c_smbus_read_block_data(struct i2c_client * client,
	u8 command, u8 *values);		u8 command, u8 *values);
	extern s32 i2c_smbus_write_block_data(struct i2c_client * client,		extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
	@@ -621,8 +623,6 @@ These ones were removed from i2c-core because they had no users, but could
	be added back later if needed:		be added back later if needed:

	extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);		extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
	extern s32 i2c_smbus_process_call(struct i2c_client * client,
	u8 command, u16 value);
	extern s32 i2c_smbus_block_process_call(struct i2c_client *client,		extern s32 i2c_smbus_block_process_call(struct i2c_client *client,
	u8 command, u8 length,		u8 command, u8 length,
	u8 *values)		u8 *values)

arch/arm/mach-omap1/board-h3.c

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -476,6 +476,10 @@ static struct i2c_board_info __initdata h3_i2c_board_info[] = {
	I2C_BOARD_INFO("tps65013", 0x48),		I2C_BOARD_INFO("tps65013", 0x48),
	/* .irq = OMAP_GPIO_IRQ(??), */		/* .irq = OMAP_GPIO_IRQ(??), */
	},		},
			{
			I2C_BOARD_INFO("isp1301_omap", 0x2d),
			.irq = OMAP_GPIO_IRQ(14),
			},
	};		};

	static struct omap_gpio_switch h3_gpio_switches[] __initdata = {		static struct omap_gpio_switch h3_gpio_switches[] __initdata = {

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