[U-Boot] [PATCH V3] i2c: mxc: refactor i2c driver and support dm

[Simon Glass]

On 27 April 2015 at 07:36, Peng Fan <Peng.Fan at freescale.com> wrote:
>
> 1. Introduce a new structure `struct mxc_i2c_bus`, this structure will
>    used for non-DM and DM.
> 2. Remove `struct mxc_i2c_regs` structure, but use register offset to access
>    registers based on `base` entry of `struct mxc_i2c_bus`.
> 3. Remove most `#ifdef I2C_QUIRK_REG`. Using driver_data to contain platform
>    flags. A new flag is introduced, I2C_QUIRK_FLAG.
> 4. Most functions use `struct mxc_i2c_bus` as one of the parameters.
>    Make most functions common to DM and non-DM, try to avoid duplicated code.
> 5. Support DM. Pinmux setting is still set by setup_i2c, but we do not
>    need bus_i2c_init for DM.
> 6. struct i2c_parms and struct sram_data are removed.
> 7. Remove bus_i2c_read bus_i2c_write prototype in header file. The frist
>    paramter of bus_i2c_init is modified to i2c index. Add new prototype
>    i2c_idle_bus and force_idle_bus. Since bus_i2c_init is not good for
>    DM I2C and pinctrl is missed, we use a weak function for i2c_idle_bus
>    for DM part.
>    Board file take the responsibility to implement this function, like this:
>    "
>    int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
>    {
>            if (i2c_bus->index == 0)
>                    force_idle_bus(i2c_pads_info0);
>            else if (i2c_bus->index == 1)
>                    force_idle_bus(i2c_pads_info1);
>            else
>                    xxxxxx
>    }
>    "
>
> Signed-off-by: Peng Fan <Peng.Fan at freescale.com>
> ---
>
> Changes v3:
>  1. remove bus_i2c_init for DM, introuduce a weak function i2c_idle_bus.
>  2. remove static return type for force_idle_bus, since we need to call
>     it in i2c_idle_bus which may be implemented in board file. This does
>     not hurt for non-DM.

Acked-by: Simon Glass <sjg at chromium.org>

>
> Changes v2:
>  1. Refactor driver, remove register access based on structure, but use
>    'base + offset'
>  2. Introduce mxc_i2c_bus structure
>  3. Introduce I2C_QUIRK_FLAG and remove most I2C_QUIRK_REG and use
>     driver_data to contain the flags for different platforms
>  4. Avoid duplicated code between DM and non-DM part
>  5. The function name i2c_init_transfer is not changed.
>  6. Remove bus_i2c_read/write prototype from header file
>  7. change bus_i2c_init's first parameter to i2c index
>  8. Rename patch name, since refactor non-DM part.
>
>  arch/arm/imx-common/i2c-mxv7.c            |   7 +-
>  arch/arm/include/asm/imx-common/mxc_i2c.h |  38 +-
>  drivers/i2c/mxc_i2c.c                     | 575 ++++++++++++++++++++----------
>  3 files changed, 426 insertions(+), 194 deletions(-)
>