33 lines
1.3 KiB
Plaintext
33 lines
1.3 KiB
Plaintext
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Introduction
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============
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Gadget serial driver is divided into two parts.
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1. f_serial.c : Interacts with USB Gadget Layer
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2. u_serial.c : Interacts with TTY Layer
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Gadget sdio driver adds capability to interact with SDIO Layer in
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case modem device is inter-connected with sdio interface.
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S/W Description
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===============
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Gadget SDIO driver is a simple bridge driver between usb serial
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gadget and sdio abstraction layer. It registers with sdio
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abstraction layer with read/write call backs and provides
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USB connect/disconnect call backs usb gadget serial driver.
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S/W Control Flow:
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=================
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Driver maintains two sdio channels, one for data and one for control.
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Data pipe is dedicated sdio channel where as control is a muxed channel.
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Incase of sdio control pipe, driver registers for control information
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chagnes from modem side. Whenever new information is available, it
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would queue a interrupt endpoint w/ new info. Laptop can also send the
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DTR and RTS information as part of SET Encapsulated command.
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Data pipe of sdio channel also has notification mechanism to indicate
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the READ/WRITE availability. When READ is available on SDIO pipe,
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driver would read the data and hands it over to USB In ept and when
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it receives the data from USB driver would queue the same to SDIO
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channel(if write buffers are available).
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