From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH V6 05/21] clk: tegra: pllout: Save and restore pllout context Date: Mon, 22 Jul 2019 01:18:44 +0300 Message-ID: <2990f6b1-a43f-d910-6743-1c13e029ce36@gmail.com> References: <1563738060-30213-1-git-send-email-skomatineni@nvidia.com> <1563738060-30213-6-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <1563738060-30213-6-git-send-email-skomatineni@nvidia.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org 21.07.2019 22:40, Sowjanya Komatineni пишет: > This patch implements save and restore of pllout context. > > During system suspend, core power goes off and looses the settings > of the Tegra CAR controller registers. > > So during suspend entry the state of pllout is saved and on resume > it is restored back to have pllout in same state as before suspend. > > pllout rate is saved and restore in clock divider so it will be at > same rate as before suspend when pllout state is restored. > > Acked-by: Thierry Reding > Signed-off-by: Sowjanya Komatineni > --- > drivers/clk/tegra/clk-pll-out.c | 28 ++++++++++++++++++++++++++++ > drivers/clk/tegra/clk-tegra210.c | 3 ++- > drivers/clk/tegra/clk.h | 9 +++++++++ > 3 files changed, 39 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/tegra/clk-pll-out.c b/drivers/clk/tegra/clk-pll-out.c > index 35f2bf00e1e6..8f26a7e3e579 100644 > --- a/drivers/clk/tegra/clk-pll-out.c > +++ b/drivers/clk/tegra/clk-pll-out.c > @@ -69,10 +69,38 @@ static void clk_pll_out_disable(struct clk_hw *hw) > spin_unlock_irqrestore(pll_out->lock, flags); > } > > +static int tegra_clk_pll_out_save_context(struct clk_hw *hw) > +{ > + struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw); > + > + if (pll_out->flags & TEGRA_PLLRE_OUT) > + pll_out->pllout_ctx = readl_relaxed(pll_out->reg); > + else > + pll_out->pllout_ctx = clk_hw_get_rate(hw); This is unused? > + return 0; > +} > + > +static void tegra_clk_pll_out_restore_context(struct clk_hw *hw) > +{ > + struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw); > + > + if (pll_out->flags & TEGRA_PLLRE_OUT) { > + writel_relaxed(pll_out->pllout_ctx, pll_out->reg); > + } else { > + if (!__clk_get_enable_count(hw->clk)) > + clk_pll_out_disable(hw); > + else > + clk_pll_out_enable(hw); > + } > +} > + > const struct clk_ops tegra_clk_pll_out_ops = { > .is_enabled = clk_pll_out_is_enabled, > .enable = clk_pll_out_enable, > .disable = clk_pll_out_disable, > + .save_context = tegra_clk_pll_out_save_context, > + .restore_context = tegra_clk_pll_out_restore_context, > }; > > struct clk *tegra_clk_register_pll_out(const char *name, > diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c > index df172d5772d7..4721ee030d1c 100644 > --- a/drivers/clk/tegra/clk-tegra210.c > +++ b/drivers/clk/tegra/clk-tegra210.c > @@ -3200,7 +3200,8 @@ static void __init tegra210_pll_init(void __iomem *clk_base, > 8, 8, 1, NULL); > clk = tegra_clk_register_pll_out("pll_re_out1", "pll_re_out1_div", > clk_base + PLLRE_OUT1, 1, 0, > - CLK_SET_RATE_PARENT, 0, NULL); > + CLK_SET_RATE_PARENT, TEGRA_PLLRE_OUT, > + NULL); > clks[TEGRA210_CLK_PLL_RE_OUT1] = clk; > > /* PLLE */ > diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h > index 83623f5f55f3..fb29a8c27873 100644 > --- a/drivers/clk/tegra/clk.h > +++ b/drivers/clk/tegra/clk.h > @@ -439,6 +439,12 @@ struct clk *tegra_clk_register_pllu_tegra210(const char *name, > * @rst_bit_idx: bit to reset PLL divider > * @lock: register lock > * @flags: hardware-specific flags > + * @pllout_ctx: pllout context to save and restore during suspend > + * and resume > + * > + * Flags: > + * TEGRA_PLLRE_OUT - This flag indicates that it is PLLRE_OUT and is used to > + * identify PLLRE_OUT during clk_pll_out save and restore. > */ > struct tegra_clk_pll_out { > struct clk_hw hw; > @@ -447,8 +453,11 @@ struct tegra_clk_pll_out { > u8 rst_bit_idx; > spinlock_t *lock; > u8 flags; > + unsigned int pllout_ctx; u32 > }; > > +#define TEGRA_PLLRE_OUT BIT(0) > + > #define to_clk_pll_out(_hw) container_of(_hw, struct tegra_clk_pll_out, hw) > > extern const struct clk_ops tegra_clk_pll_out_ops; >