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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-15 23:56:35 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-15 23:56:35 +0300 |
commit | 8600b697cd4787ac3ce053d48ca7301836fd0c55 (patch) | |
tree | ba0771e53ffb66b2c077b54f620d9bb78b43ba79 /Documentation/i2c | |
parent | 0ab7b12c49b6fbf2d4d0381374b82935f949be5f (diff) | |
parent | 6eb89ef029fe22aee518a9dc75b9ee5d6ef9b3fe (diff) | |
download | linux-8600b697cd4787ac3ce053d48ca7301836fd0c55.tar.xz |
Merge branch 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
- the first series of making i2c_device_id optional instead of
mandatory (in favor of alternatives like of_device_id).
This involves adding a new probe callback (probe_new) which removes
some peculiarities I2C had for a long time now. The new probe is
matching the other subsystems now and the old one will be removed
once all users are converted. It is expected to take a while but
there is ongoing interest in that.
- SMBus Host Notify introduced 4.9 got refactored. They are now using
interrupts instead of the alert callback which solves multiple
issues.
- new drivers for iMX LowPower I2C, Mellanox CPLD and its I2C mux
- significant refactoring for bcm2835 driver
- the usual set of driver updates and improvements
* 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (46 commits)
i2c: fsl-lpi2c: read lpi2c fifo size in probe()
i2c: octeon: thunderx: Remove double-check after interrupt
i2c: octeon: thunderx: TWSI software reset in recovery
i2c: cadence: Allow Cadence I2C to be selected for Cadence Xtensa CPUs
i2c: sh_mobile: Add per-Generation fallback bindings
i2c: rcar: Add per-Generation fallback bindings
i2c: imx-lpi2c: add low power i2c bus driver
dt-bindings: i2c: imx-lpi2c: add devicetree bindings
i2c: designware-pcidrv: Add 10bit address feature to medfield/merrifield
i2c: pxa: Add support for the I2C units found in Armada 3700
i2c: pxa: Add definition of fast and high speed modes via the regs layout
dt-bindings: i2c: pxa: Update the documentation for the Armada 3700
i2c: qup: support SMBus block read
i2c: qup: add ACPI support
i2c: designware: Consolidate default functionality bits
i2c: i2c-mux-gpio: update mux with gpiod_set_array_value_cansleep
i2c: mux: pca954x: Add ACPI support for pca954x
i2c: use an IRQ to report Host Notify events, not alert
i2c: i801: remove SMBNTFDDAT reads as they always seem to return 0
i2c: i801: use the BIT() macro for FEATURES_* also
...
Diffstat (limited to 'Documentation/i2c')
-rw-r--r-- | Documentation/i2c/busses/i2c-mlxcpld | 47 | ||||
-rw-r--r-- | Documentation/i2c/smbus-protocol | 12 |
2 files changed, 55 insertions, 4 deletions
diff --git a/Documentation/i2c/busses/i2c-mlxcpld b/Documentation/i2c/busses/i2c-mlxcpld new file mode 100644 index 000000000000..4e46c440b38d --- /dev/null +++ b/Documentation/i2c/busses/i2c-mlxcpld @@ -0,0 +1,47 @@ +Driver i2c-mlxcpld + +Author: Michael Shych <michaelsh@mellanox.com> + +This is the Mellanox I2C controller logic, implemented in Lattice CPLD +device. +Device supports: + - Master mode. + - One physical bus. + - Polling mode. + +This controller is equipped within the next Mellanox systems: +"msx6710", "msx6720", "msb7700", "msn2700", "msx1410", "msn2410", "msb7800", +"msn2740", "msn2100". + +The next transaction types are supported: + - Receive Byte/Block. + - Send Byte/Block. + - Read Byte/Block. + - Write Byte/Block. + +Registers: +CTRL 0x1 - control reg. + Resets all the registers. +HALF_CYC 0x4 - cycle reg. + Configure the width of I2C SCL half clock cycle (in 4 LPC_CLK + units). +I2C_HOLD 0x5 - hold reg. + OE (output enable) is delayed by value set to this register + (in LPC_CLK units) +CMD 0x6 - command reg. + Bit 0, 0 = write, 1 = read. + Bits [7:1] - the 7bit Address of the I2C device. + It should be written last as it triggers an I2C transaction. +NUM_DATA 0x7 - data size reg. + Number of data bytes to write in read transaction +NUM_ADDR 0x8 - address reg. + Number of address bytes to write in read transaction. +STATUS 0x9 - status reg. + Bit 0 - transaction is completed. + Bit 4 - ACK/NACK. +DATAx 0xa - 0x54 - 68 bytes data buffer regs. + For write transaction address is specified in four first bytes + (DATA1 - DATA4), data starting from DATA4. + For read transactions address is sent in a separate transaction and + specified in the four first bytes (DATA0 - DATA3). Data is read + starting from DATA0. diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol index 14d4ec1be245..092d474f5843 100644 --- a/Documentation/i2c/smbus-protocol +++ b/Documentation/i2c/smbus-protocol @@ -200,10 +200,14 @@ alerting device's address. [S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P] This is implemented in the following way in the Linux kernel: -* I2C bus drivers which support SMBus Host Notify should call - i2c_setup_smbus_host_notify() to setup SMBus Host Notify support. -* I2C drivers for devices which can trigger SMBus Host Notify should implement - the optional alert() callback. +* I2C bus drivers which support SMBus Host Notify should report + I2C_FUNC_SMBUS_HOST_NOTIFY. +* I2C bus drivers trigger SMBus Host Notify by a call to + i2c_handle_smbus_host_notify(). +* I2C drivers for devices which can trigger SMBus Host Notify will have + client->irq assigned to a Host Notify IRQ if noone else specified an other. + +There is currently no way to retrieve the data parameter from the client. Packet Error Checking (PEC) |