Re: [PATCH v2 1/4] mfd: Kontron PLD mfd driver

[Linus Walleij]

On Tue, Jun 18, 2013 at 11:04 PM, Kevin Strasser
<kevin.strasser@xxxxxxxxxxxxxxx> wrote:
> Add core MFD driver for the on-board PLD found on some Kontron embedded
> modules. The PLD device may provide functions like watchdog, GPIO, UART
> and I2C bus.
>
> The following modules are supported:
>         * COMe-bIP#
>         * COMe-bPC2 (ETXexpress-PC)
>         * COMe-bSC# (ETXexpress-SC T#)
>         * COMe-cCT6
>         * COMe-cDC2 (microETXexpress-DC)
>         * COMe-cPC2 (microETXexpress-PC)
>         * COMe-mCT10
>         * ETX-OH
>
> Signed-off-by: Kevin Strasser <kevin.strasser@xxxxxxxxxxxxxxx>
> Signed-off-by: Michael Brunner <michael.brunner@xxxxxxxxxxx>
> Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Acked-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx>

(...)
> +/**
> + * kempld_read8 - read 8 bit register
> + * @pld: kempld_device_data structure describing the PLD
> + * @index: register index on the chip
> + *
> + * kempld_get_mutex must be called prior to calling this function.
> + */
> +u8 kempld_read8(struct kempld_device_data *pld, u8 index)
> +{
> +       iowrite8(index, pld->io_index);
> +       return ioread8(pld->io_data);
> +}
> +EXPORT_SYMBOL_GPL(kempld_read8);
> +
> +/**
> + * kempld_write8 - write 8 bit register
> + * @pld: kempld_device_data structure describing the PLD
> + * @index: register index on the chip
> + * @data: new register value
> + *
> + * kempld_get_mutex must be called prior to calling this function.
> + */
> +void kempld_write8(struct kempld_device_data *pld, u8 index, u8 data)
> +{
> +       iowrite8(index, pld->io_index);
> +       iowrite8(data, pld->io_data);
> +}
> +EXPORT_SYMBOL_GPL(kempld_write8);
> +
> +/**
> + * kempld_read16 - read 16 bit register
> + * @pld: kempld_device_data structure describing the PLD
> + * @index: register index on the chip
> + *
> + * kempld_get_mutex must be called prior to calling this function.
> + */
> +u16 kempld_read16(struct kempld_device_data *pld, u8 index)
> +{
> +       return kempld_read8(pld, index) | kempld_read8(pld, index + 1) << 8;
> +}
> +EXPORT_SYMBOL_GPL(kempld_read16);
> +
> +/**
> + * kempld_write16 - write 16 bit register
> + * @pld: kempld_device_data structure describing the PLD
> + * @index: register index on the chip
> + * @data: new register value
> + *
> + * kempld_get_mutex must be called prior to calling this function.
> + */
> +void kempld_write16(struct kempld_device_data *pld, u8 index, u16 data)
> +{
> +       kempld_write8(pld, index, (u8)data);
> +       kempld_write8(pld, index + 1, (u8)(data >> 8));
> +}
> +EXPORT_SYMBOL_GPL(kempld_write16);
> +
> +/**
> + * kempld_read32 - read 32 bit register
> + * @pld: kempld_device_data structure describing the PLD
> + * @index: register index on the chip
> + *
> + * kempld_get_mutex must be called prior to calling this function.
> + */
> +u32 kempld_read32(struct kempld_device_data *pld, u8 index)
> +{
> +       return kempld_read16(pld, index) | kempld_read16(pld, index + 2) << 16;
> +}
> +EXPORT_SYMBOL_GPL(kempld_read32);
> +
> +/**
> + * kempld_write32 - write 32 bit register
> + * @pld: kempld_device_data structure describing the PLD
> + * @index: register index on the chip
> + * @data: new register value
> + *
> + * kempld_get_mutex must be called prior to calling this function.
> + */
> +void kempld_write32(struct kempld_device_data *pld, u8 index, u32 data)
> +{
> +       kempld_write16(pld, index, (u16)data);
> +       kempld_write16(pld, index + 2, (u16)(data >> 16));
> +}
> +EXPORT_SYMBOL_GPL(kempld_write32);
(...)
> +extern u8 kempld_read8(struct kempld_device_data *pld, u8 index);
> +extern void kempld_write8(struct kempld_device_data *pld, u8 index, u8 data);
> +extern u16 kempld_read16(struct kempld_device_data *pld, u8 index);
> +extern void kempld_write16(struct kempld_device_data *pld, u8 index, u16 data);
> +extern u32 kempld_read32(struct kempld_device_data *pld, u8 index);
> +extern void kempld_write32(struct kempld_device_data *pld, u8 index, u32 data);

Not really my business, but I think if I was to implement this
inter-module API I would use regmap for this read/write marshalling
right here.

Yours,
Linus Walleij
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