On 26/05/2020 11:12, Roger Lu wrote:

Hi Matthias,

Thanks for the feedback.

On Fri, 2020-05-22 at 17:38 +0200, Matthias Brugger wrote:

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On 22/05/2020 11:40, Roger Lu wrote:

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Hi Enric,

On Tue, 2020-05-19 at 17:30 +0200, Enric Balletbo Serra wrote:

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Hi Roger,

Thank you for your patch. I have the feeling that this driver is
complex and difficult to follow and I am wondering if it wouldn't be
better if you can send a version that simply adds basic functionality
for now. Some comments below.

Thanks for the advices. I'll submit SVS v9 with basic functionality
patch + step by step functionalities' patches. 

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Missatge de Roger Lu [off-list ref] del dia dl., 18 de maig
2020 a les 11:25:

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The SVS (Smart Voltage Scaling) engine is a piece
of hardware which is used to calculate optimized
voltage values of several power domains,
e.g. CPU/GPU/CCI, according to chip process corner,
temperatures, and other factors. Then DVFS driver
could apply those optimized voltage values to reduce
power consumption.

Signed-off-by: Roger Lu <redacted>
---
 drivers/power/avs/Kconfig     |   10 +
 drivers/power/avs/Makefile    |    1 +
 drivers/power/avs/mtk_svs.c   | 2119 +++++++++++++++++++++++++++++++++
 include/linux/power/mtk_svs.h |   23 +
 4 files changed, 2153 insertions(+)
 create mode 100644 drivers/power/avs/mtk_svs.c
 create mode 100644 include/linux/power/mtk_svs.h

diff --git a/drivers/power/avs/Kconfig b/drivers/power/avs/Kconfig
index cdb4237bfd02..67089ac6040e 100644
--- a/drivers/power/avs/Kconfig
+++ b/drivers/power/avs/Kconfig

@@ -35,3 +35,13 @@ config ROCKCHIP_IODOMAIN
          Say y here to enable support io domains on Rockchip SoCs. It is
          necessary for the io domain setting of the SoC to match the
          voltage supplied by the regulators.
+
+config MTK_SVS
+       bool "MediaTek Smart Voltage Scaling(SVS)"

Can't be this a module? Why? In such case, you should use tristate option

Generally, MTK_SVS is needed in MTK SoC(mt81xx) products. So, we don't provide
module option in config. If, somehow, SVS isn't needed, we suggest
CONFIG_MTK_SVS=n to be set.

The question here is if it needs to be probed before we probe the modules. If
not, we should add a Kconfig option for MT81xx SoCs to select MTK_SVS.

Excuse me to make you confuse. MT81xx SoCs is the subset MTK ICs that
will use CONFIG_MTK_SVS. In other words, CONFIG_MTK_SVS will be used
with other MTK ICs as well. So, MTK_SVS is the general naming for MTK IC
to enable SVS power feature. Anyway, back to Enric's question, I'll make
MTK_SVS become a tristate feature in the next patch. Thanks.

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[...]

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+
+static const u32 svs_regs_v2[] = {

Is this SoC specific or shared between SoCs?

Shared between SoCs. Some SVS in MTK SoCs use v2 register map.

And which silicon uses v1 then? Is v2 a MediaTek internal naming you want to keep?

1. MT8173 IC uses v1 register map. 
2. Yes, I'll keep v2 postfix.

Sounds good, thanks for clarification.

Regards,
Matthias