diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/smsc_ece1099.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/smsc_ece1099.txt')
-rw-r--r-- | kernel/Documentation/smsc_ece1099.txt | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/kernel/Documentation/smsc_ece1099.txt b/kernel/Documentation/smsc_ece1099.txt new file mode 100644 index 000000000..6b492e82b --- /dev/null +++ b/kernel/Documentation/smsc_ece1099.txt @@ -0,0 +1,56 @@ +What is smsc-ece1099? +---------------------- + +The ECE1099 is a 40-Pin 3.3V Keyboard Scan Expansion +or GPIO Expansion device. The device supports a keyboard +scan matrix of 23x8. The device is connected to a Master +via the SMSC BC-Link interface or via the SMBus. +Keypad scan Input(KSI) and Keypad Scan Output(KSO) signals +are multiplexed with GPIOs. + +Interrupt generation +-------------------- + +Interrupts can be generated by an edge detection on a GPIO +pin or an edge detection on one of the bus interface pins. +Interrupts can also be detected on the keyboard scan interface. +The bus interrupt pin (BC_INT# or SMBUS_INT#) is asserted if +any bit in one of the Interrupt Status registers is 1 and +the corresponding Interrupt Mask bit is also 1. + +In order for software to determine which device is the source +of an interrupt, it should first read the Group Interrupt Status Register +to determine which Status register group is a source for the interrupt. +Software should read both the Status register and the associated Mask register, +then AND the two values together. Bits that are 1 in the result of the AND +are active interrupts. Software clears an interrupt by writing a 1 to the +corresponding bit in the Status register. + +Communication Protocol +---------------------- + +- SMbus slave Interface + The host processor communicates with the ECE1099 device + through a series of read/write registers via the SMBus + interface. SMBus is a serial communication protocol between + a computer host and its peripheral devices. The SMBus data + rate is 10KHz minimum to 400 KHz maximum + +- Slave Bus Interface + The ECE1099 device SMBus implementation is a subset of the + SMBus interface to the host. The device is a slave-only SMBus device. + The implementation in the device is a subset of SMBus since it + only supports four protocols. + + The Write Byte, Read Byte, Send Byte, and Receive Byte protocols are the + only valid SMBus protocols for the device. + +- BC-LinkTM Interface + The BC-Link is a proprietary bus that allows communication + between a Master device and a Companion device. The Master + device uses this serial bus to read and write registers + located on the Companion device. The bus comprises three signals, + BC_CLK, BC_DAT and BC_INT#. The Master device always provides the + clock, BC_CLK, and the Companion device is the source for an + independent asynchronous interrupt signal, BC_INT#. The ECE1099 + supports BC-Link speeds up to 24MHz. |