lkml.org 
[lkml]   [2018]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH v2 3/3] gpio: Add Spreadtrum PMIC EIC driver support
    Hi Andy,

    On 25 February 2018 at 20:19, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
    > On Sat, Feb 24, 2018 at 12:44 PM, Baolin Wang <baolin.wang@linaro.org> wrote:
    >> The Spreadtrum PMIC EIC controller contains only one bank of debounce EIC,
    >> and this bank contains 16 EICs. Each EIC can only be used as input mode,
    >> as well as supporting the debounce and the capability to trigger interrupts
    >> when detecting input signals.
    >
    >> +/*
    >> + * These registers are modified under the irq bus lock and cached to avoid
    >> + * unnecessary writes in bus_sync_unlock.
    >> + */
    >> +enum { REG_IEV, REG_IE, REG_TRIG, CACHE_NR_REGS };
    >
    > One item per line.

    Sure.

    >
    >> +static int sprd_pmic_eic_direction_input(struct gpio_chip *chip,
    >> + unsigned int offset)
    >> +{
    >> + /* EICs are always input, nothing need to do here. */
    >> + return 0;
    >> +}
    >> +
    >> +static void sprd_pmic_eic_set(struct gpio_chip *chip, unsigned int offset,
    >> + int value)
    >> +{
    >> + /* EICs are always input, nothing need to do here. */
    >> +}
    >
    > Remove both.
    >
    > Look at what GPIO core does.

    I've checked the GPIO core, we need the
    sprd_pmic_eic_direction_input() returns 0, since user can set GPIOD_IN
    flag when requesting one GPIO, otherwise it will return errors.
    We also need one dummy sprd_pmic_eic_set() when setting debounce for
    one GPIO, otherwise it will return errors.

    >
    >> + value |= debounce / 1000;
    >
    > Possible overflow.

    OK. I should & SPRD_PMIC_EIC_DBC_MASK.

    >
    >> + for (n = 0; n < chip->ngpio; n++) {
    >> + if (!(BIT(n) & val))
    >
    > for_each_set_bit().
    >
    > At some point you may need just to go across lib/ in the kernel and
    > see what we have there.

    I've considered the for_each_set_bit(), it need one 'unsigned long'
    type parameter, but we get the value from regmap is 'u32' type. So we
    need one extra conversion from 'u32' to 'unsigned long' like:

    unsigned long reg = val;

    for_each_set_bit(n, &reg, chip->ngpio) {
    .......
    }

    If you like this conversion, then I can change to use
    for_each_set_bit(). Thanks.

    --
    Baolin.wang
    Best Regards

    \
     
     \ /
      Last update: 2018-02-26 04:01    [W:5.756 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site