[PATCH V2 3/8] clk: tegra114: add LP1 suspend/resume support
From: Joseph Lo <hidden>
Date: 2013-08-05 11:20:59
Also in:
linux-tegra
Subsystem:
common clk framework, tegra clock driver, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Peter De Schrijver, Prashant Gaikwad, Linus Torvalds
When the system suspends to LP1, the CPU clock source is switched to CLK_M (12MHz Oscillator) during suspend/resume flow. The CPU clock source is controlled by the CCLKG_BURST_POLICY register, and hence this register must be restored during LP1 resume. Cc: Mike Turquette <redacted> Signed-off-by: Joseph Lo <redacted> --- V2: * update the commit message --- drivers/clk/tegra/clk-tegra114.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
index f74ed19..b0e745a 100644
--- a/drivers/clk/tegra/clk-tegra114.c
+++ b/drivers/clk/tegra/clk-tegra114.c@@ -22,6 +22,7 @@ #include <linux/of_address.h> #include <linux/delay.h> #include <linux/export.h> +#include <linux/syscore_ops.h> #include <linux/clk/tegra.h> #include "clk.h"
@@ -2332,6 +2333,33 @@ void tegra114_clock_deassert_dfll_dvco_reset(void) } EXPORT_SYMBOL(tegra114_clock_deassert_dfll_dvco_reset); +#ifdef CONFIG_PM_SLEEP +static u32 clk_rst_suspend[2]; + +static int tegra114_clk_suspend(void) +{ + u32 *ctx = clk_rst_suspend; + + *ctx++ = readl_relaxed(clk_base + CCLKG_BURST_POLICY); + *ctx++ = readl_relaxed(clk_base + CCLKG_BURST_POLICY + 4); + + return 0; +} + +static void tegra114_clk_resume(void) +{ + u32 *ctx = clk_rst_suspend; + + writel_relaxed(*ctx++, clk_base + CCLKG_BURST_POLICY); + writel_relaxed(*ctx++, clk_base + CCLKG_BURST_POLICY + 4); +} + +static struct syscore_ops tegra114_clk_syscore_ops = { + .suspend = tegra114_clk_suspend, + .resume = tegra114_clk_resume, +}; +#endif + static void __init tegra114_clock_init(struct device_node *np) { struct device_node *node;
@@ -2384,5 +2412,9 @@ static void __init tegra114_clock_init(struct device_node *np) tegra_clk_apply_init_table = tegra114_clock_apply_init_table; tegra_cpu_car_ops = &tegra114_cpu_car_ops; + +#ifdef CONFIG_PM_SLEEP + register_syscore_ops(&tegra114_clk_syscore_ops); +#endif } CLK_OF_DECLARE(tegra114, "nvidia,tegra114-car", tegra114_clock_init);
--
1.8.3.4