Re: [PATCH v4 3/3] mfd: arizona: Refactor arizona_poll_reg

From: Lee Jones
Date: Thu Mar 23 2017 - 06:54:43 EST


On Wed, 15 Mar 2017, Charles Keepax wrote:

> Currently, we specify the timeout in terms of the number of polls but it
> is more clear from a user of the functions perspective to specify the
> timeout directly in milliseconds, as such update the function to these new
> semantics.
>
> Additionally, arizona_poll_reg essentially hard-codes
> regmap_read_poll_timeout, update the implementation to use
> regmap_read_poll_timeout. We still keep arizona_poll_reg around as
> regmap_read_poll_timeout is a macro so rather than expand this for each
> caller keep it wrapped in arizona_poll_reg.
>
> Whilst we are doing this make the timeouts a little more generous as
> the previous system had a bit more slack as it was done as a delay per
> iteration of the loop whereas regmap_read_poll_timeout compares ktime's.
>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
>
> Changes since v3:
> - Squashed together patches 3/4 from the v3 chain.
>
> Thanks,
> Charles
>
> drivers/mfd/arizona-core.c | 36 ++++++++++++++++--------------------
> 1 file changed, 16 insertions(+), 20 deletions(-)

Much better, thanks.

Applied, thanks.

> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
> index 4cb34c3..75488e6 100644
> --- a/drivers/mfd/arizona-core.c
> +++ b/drivers/mfd/arizona-core.c
> @@ -235,29 +235,25 @@ static irqreturn_t arizona_overclocked(int irq, void *data)
> return IRQ_HANDLED;
> }
>
> +#define ARIZONA_REG_POLL_DELAY_US 7500
> +
> static int arizona_poll_reg(struct arizona *arizona,
> - int timeout, unsigned int reg,
> + int timeout_ms, unsigned int reg,
> unsigned int mask, unsigned int target)
> {
> unsigned int val = 0;
> - int ret, i;
> -
> - for (i = 0; i < timeout; i++) {
> - ret = regmap_read(arizona->regmap, reg, &val);
> - if (ret != 0) {
> - dev_err(arizona->dev, "Failed to read reg 0x%x: %d\n",
> - reg, ret);
> - continue;
> - }
> -
> - if ((val & mask) == target)
> - return 0;
> + int ret;
>
> - usleep_range(1000, 5000);
> - }
> + ret = regmap_read_poll_timeout(arizona->regmap,
> + ARIZONA_INTERRUPT_RAW_STATUS_5, val,
> + ((val & mask) == target),
> + ARIZONA_REG_POLL_DELAY_US,
> + timeout_ms * 1000);
> + if (ret)
> + dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n",
> + reg, val);
>
> - dev_err(arizona->dev, "Polling reg 0x%x timed out: %x\n", reg, val);
> - return -ETIMEDOUT;
> + return ret;
> }
>
> static int arizona_wait_for_boot(struct arizona *arizona)
> @@ -269,7 +265,7 @@ static int arizona_wait_for_boot(struct arizona *arizona)
> * we won't race with the interrupt handler as it'll be blocked on
> * runtime resume.
> */
> - ret = arizona_poll_reg(arizona, 5, ARIZONA_INTERRUPT_RAW_STATUS_5,
> + ret = arizona_poll_reg(arizona, 30, ARIZONA_INTERRUPT_RAW_STATUS_5,
> ARIZONA_BOOT_DONE_STS, ARIZONA_BOOT_DONE_STS);
>
> if (!ret)
> @@ -339,7 +335,7 @@ static int arizona_enable_freerun_sysclk(struct arizona *arizona,
> ret);
> return ret;
> }
> - ret = arizona_poll_reg(arizona, 25, ARIZONA_INTERRUPT_RAW_STATUS_5,
> + ret = arizona_poll_reg(arizona, 180, ARIZONA_INTERRUPT_RAW_STATUS_5,
> ARIZONA_FLL1_CLOCK_OK_STS,
> ARIZONA_FLL1_CLOCK_OK_STS);
> if (ret)
> @@ -403,7 +399,7 @@ static int wm5102_apply_hardware_patch(struct arizona *arizona)
> goto err;
> }
>
> - ret = arizona_poll_reg(arizona, 5, ARIZONA_WRITE_SEQUENCER_CTRL_1,
> + ret = arizona_poll_reg(arizona, 30, ARIZONA_WRITE_SEQUENCER_CTRL_1,
> ARIZONA_WSEQ_BUSY, 0);
> if (ret)
> regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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