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creating a serial ports drivers in polling mode
- From: "Franklin Woolfson" <fwoolfson at hifn dot com>
- To: "Ecos-Discuss (E-mail)" <ecos-discuss at sources dot redhat dot com>
- Date: Tue, 12 Oct 2004 13:07:52 -0700
- Subject: [ECOS] creating a serial ports drivers in polling mode
I am creating a serial hardware interface driver (chapter 17) for redboot v2.0. The UART used a DMA to transfer data and therefore would like to create a driver in polling mode. I based the driver on the ARM A91 serial device as it had 2 ports and ported my serial device's generic driver that was supplied.
1....... In the DEVTAB_ENTRY what is the difference between the "module_init" and "module_lookup" arguments.
2.......To ensure that I am running in polling mode (as appose to interrupt mode) I set the SERIAL_CHANNEL_USING_INTERUPTS "out/in_buf" and "out/in_buflen" arguments to zero, and configure the serial device buffer size to zero in the configuration tool. Is this correct or should I do something else?
3......When using polling mode in RedBoot is this done in a separate task? In SERIAL_FUNS "getc" must wait indefinitely for a char. If there is no char in the DMA buffers then I would like to put a task delay so as not to hold up the scheduler. Is there a task delay command for redBoot.
Franklin
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