Re: [PATCH v3 2/7] reset: qcom: AOSS (always on subsystem) reset controller

[Sibi S]

Hi Bjorn,
Thanks for the review.

On 03/19/2018 04:15 AM, Bjorn Andersson wrote:
> On Wed 14 Mar 02:21 PDT 2018, Sibi S wrote:
> > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> > index 7fc7769..d06bd1d 100644
> > --- a/drivers/reset/Kconfig
> > +++ b/drivers/reset/Kconfig
> > @@ -81,6 +81,16 @@ config RESET_PISTACHIO
> >   	help
> >   	  This enables the reset driver for ImgTec Pistachio SoCs.
> >   
> > +config RESET_QCOM_AOSS
> > +	bool "Qcom AOSS Reset Driver"
> > +	depends on ARCH_QCOM || COMPILE_TEST
> > +	select MFD_SYSCON
>
> Drop syscon

will drop it

> > +	help
> > +	  This enables the AOSS (always on subsystem) reset driver
> > +	  for Qualcomm SDM845 SoCs. Say Y if you want to control
> > +	  reset signals provided by AOSS for Modem, Venus, ADSP,
> > +	  GPU, Camera, Wireless, Display subsystem. Otherwise, say N.
> > +
> [..]
> > diff --git a/drivers/reset/reset-qcom-aoss.c b/drivers/reset/reset-qcom-aoss.c
> [..]
> > +static const struct regmap_config sdm845_aoss_regmap_config = {
> > +	.name		= "aoss-reset",
> > +	.reg_bits	= 32,
> > +	.reg_stride	= 4,
> > +	.val_bits	= 32,
> > +	.max_register	= 0x20000,
> > +	.fast_io	= true,
> > +};
>
> Is there a particular reason why you're setting up a regmap and not just
> operate on the ioremap region directly with readl/writel? It would save
> you a few lines of code and some runtime memory.

The idea here is to reuse the driver in modified configuration as
pdc_sync restart controller which is to be used for adsp_pil. PDC sync
reset register is a single register with multiple reset lines hence
would warrant setting up a regmap. I can remove these changes and add
them when I add pdc_sync reset controller though.

> > +
> > +static const struct qcom_aoss_reset_map sdm845_aoss_resets[] = {
> > +	[AOSS_CC_MSS_RESTART] = { 0x0, 0 },
> > +	[AOSS_CC_CAMSS_RESTART] = { 0x1000, 0 },
> > +	[AOSS_CC_VENUS_RESTART] = { 0x2000, 0 },
> > +	[AOSS_CC_GPU_RESTART] = { 0x3000, 0 },
> > +	[AOSS_CC_DISPSS_RESTART] = { 0x4000, 0 },
> > +	[AOSS_CC_WCSS_RESTART] = { 0x10000, 0 },
> > +	[AOSS_CC_LPASS_RESTART] = { 0x20000, 0 },
>
> Do you have a case where bit != 0? If not please drop the bit until it's
> necessary.

had the bit variable for the above state reason.

> > +};
> > +
> > +static const struct qcom_aoss_desc sdm845_aoss_desc = {
> > +	.config = &sdm845_aoss_regmap_config,
> > +	.resets = sdm845_aoss_resets,
> > +	/* Wait 6 32kHz sleep cycles for reset */
> > +	.delay = 200,
>
> Please move this constant into qcom_aoss_control_reset(), until there's
> a need for it to be configurable.
>
> > +	.num_resets = ARRAY_SIZE(sdm845_aoss_resets),
> > +};
> > +
> [..]
> > +static int qcom_aoss_control_reset(struct reset_controller_dev *rcdev,
> > +					unsigned long idx)
> > +{
> > +	struct qcom_aoss_reset_data *data = to_qcom_aoss_reset_data(rcdev);
> > +	int ret;
> > +
> > +	ret = qcom_aoss_control_assert(rcdev, idx);
> > +	if (ret)
> > +		return ret;
> > +
> > +	udelay(data->desc->delay);
>
> Per Documentation/timers/timers-howto.txt please use usleep_range() when
> delays are between 10us and 20ms.

will replace them

> > +
> > +	return qcom_aoss_control_deassert(rcdev, idx);
> > +}
>
> Regards,
> Bjorn

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