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    SubjectRe: [PATCH 1/2] misc/eeprom: add driver for 93xx46 EEPROMs over GPIO
    On 05/25/11 14:35, Anatolij Gustschin wrote:
    > On Wed, 25 May 2011 10:31:46 +0100
    > Jonathan Cameron <> wrote:
    >> On 05/24/11 17:02, Anatolij Gustschin wrote:
    >>> 93xx46 EEPROMs can be connected using GPIO lines. Add a generic
    >>> 93xx46 EEPROM driver using common GPIO API for such configurations.
    >>> A platform is supposed to register appropriate 93xx46 gpio device
    >>> providing GPIO interface description and using this driver
    >>> read/write/erase access to the EEPROM chip can be easily done
    >>> over sysfs files.
    >> Could you explain why this makes more sense than an spi driver and
    >> use of spi_gpio ?
    >> It's microwire compatible according to random google provided datasheet,
    >> which iirc is a particular form of spi (half duplex, spi mode 0 according
    >> to wikipedia)
    >> That would give us a more generally useful driver.
    > I thought about using spi_gpio first, then I decided to
    > do it in an independent driver since on the hardware the
    > driver was written for we additionally need to control
    > logic to hold pixel link chips in reset when eeprom access
    > is performed. Putting appropriate hacks to spi_gpio driver
    > didn't seem to be right approach. Controlling this logic
    > from user space is error-prone, too.
    Why would you need to put hacks in the spi bus driver?

    Surely they would still be in your eeprom driver.
    Basically hold the pin down - do spi transfer - raise it again

    Might need some callbacks to platform data (From the eeprom driver)
    to deal with this case...

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