From mboxrd@z Thu Jan 1 00:00:00 1970 From: Samuel Holland Subject: [PATCH v4 02/10] clk: sunxi-ng: Mark AR100 clocks as critical Date: Mon, 19 Aug 2019 22:23:03 -0500 Message-ID: <20190820032311.6506-3-samuel@sholland.org> References: <20190820032311.6506-1-samuel@sholland.org> Reply-To: samuel-RkNLwX/CsU9g9hUCZPvPmw@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org In-Reply-To: <20190820032311.6506-1-samuel-RkNLwX/CsU9g9hUCZPvPmw@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Maxime Ripard , Chen-Yu Tsai , Jassi Brar , Michael Turquette , Stephen Boyd , Rob Herring , Mark Rutland , Corentin Labbe , Vasily Khoruzhick Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Samuel Holland List-Id: devicetree@vger.kernel.org On sun8i, sun9i, and sun50i SoCs, system suspend/resume support requires firmware running on the AR100 coprocessor (the "SCP"). Such firmware can provide additional features, such as thermal monitoring and poweron/off support for boards without a PMIC. Since the AR100 may be running critical firmware, even if Linux does not know about it or directly interact with it (all requests may go through an intermediary interface such as PSCI), Linux must not turn off its clock. At this time, such power management firmware only exists for the A64 and H5 SoCs. However, it makes sense to take care of all CCU drivers now for consistency, and to ease the transition in the future once firmware is ported to the other SoCs. Leaving the clock running is safe even if no firmware is present, since the AR100 stays in reset by default. In most cases, the AR100 clock is kept enabled by Linux anyway, since it is the parent of all APB0 bus peripherals. This change only prevents Linux from turning off the AR100 clock in the rare case that no peripherals are in use. Signed-off-by: Samuel Holland --- drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c | 2 +- drivers/clk/sunxi-ng/ccu-sun8i-r.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c b/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c index 45a1ed3fe674..adf907020951 100644 --- a/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c +++ b/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c @@ -45,7 +45,7 @@ static struct ccu_div ar100_clk = { .hw.init = CLK_HW_INIT_PARENTS("ar100", ar100_r_apb2_parents, &ccu_div_ops, - 0), + CLK_IS_CRITICAL), }, }; diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-r.c b/drivers/clk/sunxi-ng/ccu-sun8i-r.c index 4646fdc61053..feef4f750943 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-r.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-r.c @@ -45,7 +45,7 @@ static struct ccu_div ar100_clk = { .hw.init = CLK_HW_INIT_PARENTS_DATA("ar100", ar100_parents, &ccu_div_ops, - 0), + CLK_IS_CRITICAL), }, }; -- 2.21.0