Re: [PATCH v3 6/7] PM / devfreq: rockchip: add devfreq driver for rk3399 dmc

From: Paul Gortmaker <paul.gortmaker@windriver.com>
To: Lin Huang <hl@rock-chips.com>
Cc: heiko@sntech.de, mark.yao@rock-chips.com,
	myungjoo.ham@samsung.com, Chanwoo Choi <cw00.choi@samsung.com>,
	airlied@linux.ie, mturquette@baylibre.com,
	dbasehore@chromium.org, sboyd@codeaurora.org,
	LKML <linux-kernel@vger.kernel.org>,
	dri-devel@lists.freedesktop.org, dianders@chromium.org,
	linux-rockchip@lists.infradead.org,
	Kyungmin Park <kyungmin.park@samsung.com>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	tixy@linaro.org, xsf@rock-chips.com, typ@rock-chips.com
Subject: Re: [PATCH v3 6/7] PM / devfreq: rockchip: add devfreq driver for rk3399 dmc
Date: Fri, 22 Jul 2016 16:24:08 -0400	[thread overview]
Message-ID: <CAP=VYLpBBXhMLdNyuYvtJ6XWn-yTof_-oEL7saB87KGY-84c9A@mail.gmail.com> (raw)
In-Reply-To: <1469178440-4668-7-git-send-email-hl@rock-chips.com>

On Fri, Jul 22, 2016 at 5:07 AM, Lin Huang <hl@rock-chips.com> wrote:
> base on dfi result, we do ddr frequency scaling, register
> dmc driver to devfreq framework, and use simple-ondemand
> policy.
>
> Signed-off-by: Lin Huang <hl@rock-chips.com>
> ---
> Changes in v3:
> - operate dram setting through sip call
> - imporve set rate flow
>
> Changes in v2:
> - None
>
> Changes in v1:
> - move dfi controller to event
> - fix set voltage sequence when set rate fail
> - change Kconfig type from tristate to bool
> - move unuse EXPORT_SYMBOL_GPL()
>
>  drivers/devfreq/Kconfig                 |   1 +
>  drivers/devfreq/Makefile                |   1 +
>  drivers/devfreq/rockchip/Kconfig        |  15 +
>  drivers/devfreq/rockchip/Makefile       |   2 +
>  drivers/devfreq/rockchip/rk3399_dmc.c   | 482 ++++++++++++++++++++++++++++++++
>  drivers/devfreq/rockchip/rockchip_dmc.c | 143 ++++++++++
>  include/soc/rockchip/rockchip_dmc.h     |  45 +++
>  7 files changed, 689 insertions(+)
>  create mode 100644 drivers/devfreq/rockchip/Kconfig
>  create mode 100644 drivers/devfreq/rockchip/Makefile
>  create mode 100644 drivers/devfreq/rockchip/rk3399_dmc.c
>  create mode 100644 drivers/devfreq/rockchip/rockchip_dmc.c
>  create mode 100644 include/soc/rockchip/rockchip_dmc.h
>
> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
> index a5be56e..cb67246 100644
> --- a/drivers/devfreq/Kconfig
> +++ b/drivers/devfreq/Kconfig
> @@ -101,5 +101,6 @@ config ARM_TEGRA_DEVFREQ
>           operating frequencies and voltages with OPP support.
>
>  source "drivers/devfreq/event/Kconfig"
> +source "drivers/devfreq/rockchip/Kconfig"
>
>  endif # PM_DEVFREQ
> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
> index 09f11d9..48e2ae6 100644
> --- a/drivers/devfreq/Makefile
> +++ b/drivers/devfreq/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE)       += governor_passive.o
>  # DEVFREQ Drivers
>  obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ)   += exynos-bus.o
>  obj-$(CONFIG_ARM_TEGRA_DEVFREQ)                += tegra-devfreq.o
> +obj-$(CONFIG_ARCH_ROCKCHIP)            += rockchip/
>
>  # DEVFREQ Event Drivers
>  obj-$(CONFIG_PM_DEVFREQ_EVENT)         += event/
> diff --git a/drivers/devfreq/rockchip/Kconfig b/drivers/devfreq/rockchip/Kconfig
> new file mode 100644
> index 0000000..7fb1cff
> --- /dev/null
> +++ b/drivers/devfreq/rockchip/Kconfig
> @@ -0,0 +1,15 @@
> +config ARM_ROCKCHIP_DMC_DEVFREQ
> +       bool "ARM ROCKCHIP DMC DEVFREQ Driver"
> +       depends on ARCH_ROCKCHIP
> +       help
> +         This adds the DEVFREQ driver framework for the rockchip dmc.
> +
> +config ARM_RK3399_DMC_DEVFREQ
> +       bool "ARM RK3399 DMC DEVFREQ Driver"

Since you are using bool Kconfigs for your driver, please do not use
module.h or MODULE_<xyz> tags in your driver, and use the builtin
register function.

Alternatively if there really is  a use case for it to be a modular driver
then use a tristate Kconfig.

THanks,
Paul.
--

> +       depends on ARM_ROCKCHIP_DMC_DEVFREQ
> +       select PM_OPP
> +       select DEVFREQ_GOV_SIMPLE_ONDEMAND
> +       help
> +          This adds the DEVFREQ driver for the RK3399 dmc. It sets the frequency
> +          for the memory controller and reads the usage counts from hardware.
> +