[PATCH V2 05/12] clk: tegra: add support for OSC clock resume

[Sowjanya Komatineni]

This patch adds support for restoring OSC control context on resume.

Signed-off-by: Sowjanya Komatineni <skomatin...@nvidia.com>
---
 drivers/clk/tegra/clk-tegra-fixed.c | 16 ++++++++++++++++
 drivers/clk/tegra/clk.h             |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/clk/tegra/clk-tegra-fixed.c 
b/drivers/clk/tegra/clk-tegra-fixed.c
index 91c38f1666c1..de94333e800c 100644
--- a/drivers/clk/tegra/clk-tegra-fixed.c
+++ b/drivers/clk/tegra/clk-tegra-fixed.c
@@ -28,7 +28,10 @@
 #define OSC_CTRL                       0x50
 #define OSC_CTRL_OSC_FREQ_SHIFT                28
 #define OSC_CTRL_PLL_REF_DIV_SHIFT     26
+#define OSC_CTRL_MASK                  (0x3f2 |        \
+                                       (0xf << OSC_CTRL_OSC_FREQ_SHIFT))
 
+static u32 osc_ctrl_ctx;
 int __init tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *clks,
                              unsigned long *input_freqs, unsigned int num,
                              unsigned int clk_m_div, unsigned long *osc_freq,
@@ -40,6 +43,7 @@ int __init tegra_osc_clk_init(void __iomem *clk_base, struct 
tegra_clk *clks,
        unsigned osc_idx;
 
        val = readl_relaxed(clk_base + OSC_CTRL);
+       osc_ctrl_ctx = val & OSC_CTRL_MASK;
        osc_idx = val >> OSC_CTRL_OSC_FREQ_SHIFT;
 
        if (osc_idx < num)
@@ -107,3 +111,15 @@ void __init tegra_fixed_clk_init(struct tegra_clk 
*tegra_clks)
                *dt_clk = clk;
        }
 }
+
+#ifdef CONFIG_PM_SLEEP
+void tegra_clk_osc_resume(void __iomem *clk_base)
+{
+       u32 val;
+
+       val = readl_relaxed(clk_base + OSC_CTRL) & ~OSC_CTRL_MASK;
+       val |= osc_ctrl_ctx;
+       writel_relaxed(val, clk_base + OSC_CTRL);
+       fence_udelay(2, clk_base);
+}
+#endif
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index ab238b2c3125..666b9d907951 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -851,6 +851,7 @@ void tegra_clk_sync_state_pll_out(struct clk *clk);
 void tegra_clk_periph_suspend(void __iomem *clk_base);
 void tegra_clk_periph_resume(void __iomem *clk_base);
 void tegra_clk_periph_force_on(u32 *clks_on, int count, void __iomem 
*clk_base);
+void tegra_clk_osc_resume(void __iomem *clk_base);
 #endif
 
 
-- 
2.7.4