Re: [PATCH v2 1/4] mfd: arizona: Factor out SYSCLK enable from wm5102 hardware patch

Lee Jones
2015-03-23T13:52:25Z

On Tue, 17 Mar 2015, Charles Keepax wrote:

> wm5102 applies a custom hardware boot sequence, for this the SYSCLK
> needs to be enabled. This patch factors out the code that enables
> SYSCLK for this sequence such that it can be used for other boot time
> operations that require SYSCLK.
>
> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> ---
>
> Changes since v1:
> - Added some comments in patch 4 to explain the exact regulator voltage
> ranges
> - Removed the reset patch, whilst I work on the suggestions by Mark, the
> rest of the series is useful in its own right and doesn't need to be
> blocked by that
>
> Thanks,
> Charles
>
> drivers/mfd/arizona-core.c | 48 ++++++++++++++++++++++++++++---------------
> 1 files changed, 31 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
> index 6ca6dfa..ef1f8aa 100644
> --- a/drivers/mfd/arizona-core.c
> +++ b/drivers/mfd/arizona-core.c
> @@ -250,7 +250,8 @@ static int arizona_wait_for_boot(struct arizona *arizona)
> return ret;
> }
>
> -static int arizona_apply_hardware_patch(struct arizona* arizona)
> +static int arizona_exec_with_sysclk(struct arizona *arizona,
> + int (*exec)(struct arizona *))
> {
> unsigned int fll, sysclk;
> int ret, err;
> @@ -292,23 +293,8 @@ static int arizona_apply_hardware_patch(struct arizona* arizona)
> goto err_fll;
> }
>
> - /* Start the write sequencer and wait for it to finish */
> - ret = regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,
> - ARIZONA_WSEQ_ENA | ARIZONA_WSEQ_START | 160);
> - if (ret != 0) {
> - dev_err(arizona->dev, "Failed to start write sequencer: %d\n",
> - ret);
> - goto err_sysclk;
> - }
> - ret = arizona_poll_reg(arizona, 5, ARIZONA_WRITE_SEQUENCER_CTRL_1,
> - ARIZONA_WSEQ_BUSY, 0);
> - if (ret != 0) {
> - regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,
> - ARIZONA_WSEQ_ABORT);
> - ret = -ETIMEDOUT;
> - }
> + ret = exec(arizona);
>
> -err_sysclk:
> err = regmap_write(arizona->regmap, ARIZONA_SYSTEM_CLOCK_1, sysclk);
> if (err != 0) {
> dev_err(arizona->dev,
> @@ -330,6 +316,34 @@ err_fll:
> return err;
> }
>
> +static int arizona_hardware_patch_wseq(struct arizona *arizona)
> +{
> + int ret;
> +
> + /* Start the write sequencer and wait for it to finish */
> + ret = regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,
> + ARIZONA_WSEQ_ENA | ARIZONA_WSEQ_START | 160);
> + if (ret != 0) {
> + dev_err(arizona->dev, "Failed to start write sequencer: %d\n",
> + ret);
> + return ret;
> + }
> + ret = arizona_poll_reg(arizona, 5, ARIZONA_WRITE_SEQUENCER_CTRL_1,
> + ARIZONA_WSEQ_BUSY, 0);
> + if (ret != 0) {
> + regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,
> + ARIZONA_WSEQ_ABORT);
> + ret = -ETIMEDOUT;
> + }
> +
> + return ret;
> +}
> +
> +static inline int arizona_apply_hardware_patch(struct arizona *arizona)
> +{
> + return arizona_exec_with_sysclk(arizona, arizona_hardware_patch_wseq);

Not sure I like this much.

What's the reason for over-complicating this? Can you just:

arizona_exec_with_sysclk(arizona);
arizona_hardware_patch_wseq(arizona);

... or if you need that call to be in the middle, split the calls up
further.

> +}
> +
> #ifdef CONFIG_PM
> static int arizona_runtime_resume(struct device *dev)
> {

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