Hi Jean, Thank you for your prompt reply. I am working on a project where a customized board sitting on the PCI slot. The board has a SMBus microcontroller which is used to control some external sensors and communicates with the ICH6 SMBus master controller on the host PC motherboard. I need to send SMBus request command packets to the microcontroller and receive SMBus response data packets from the micro which also generates an interrupt sometimes to request for immediate or urgent services. Do you have any suggestion on how to implement such an application? Thanks. MK -----Original Message----- From: Jean Delvare [mailto:khali at linux-fr.org] Sent: Monday, November 07, 2005 10:39 AM To: Gu, Mingkun Cc: lm-sensors at lm-sensors.org Subject: RE: Helps: how to use i801--SMBus functions viai2c-dev module in Linux? Hi Michael, On 2005-11-07, Mingkun Gu wrote: > With i2c-dev module, is it possible to have more than one device with > the same major number and different minor numbers? Let say, if I want to > have > > /dev/i2c/0 89 0 > /dev/i2c/1 89 1 > /dev/i2c/2 89 2 > ...... Yes, it is possible. > How can I do it? I tried to insmod the i2c-dev module twice and got > error message say "-1 File exists." The function of i2c-dev is to give userspace an access to existing i2c busses. It doesn't create anything per se. If the only I2C/SMBus you have on your system is the i2c-i801, you'll only have /dev/i2c/0. Note that it is OK to open the same device file twice, if you need to do that. Both sessions will be independant. You need to do that if there are several chips on the bus and you want to drive them all from userspace. > One more thing is whether this module provides the ability to handle > interrupts? The question isn't relevant for i2c-dev, as it doesn't actually drive the hardware. It only acts as a bridge. As for i2c-i801, no, it is poll-based, not interrupt-based. Mark Hoffman had attempted to convert the driver to interrupt-based, but never completed the work. -- Jean Delvare ----------------------------------------- This email may contain confidential and privileged material for the sole use of the intended recipient(s). Any review, use, retention, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender by reply email and delete all copies of this message. Also, email is susceptible to data corruption, interception, tampering, unauthorized amendment and viruses. We only send and receive emails on the basis that we are not liable for any such corruption, interception, tampering, amendment or viruses or any consequence thereof.
