Commit 50d4da9b authored by Sowjanya Komatineni's avatar Sowjanya Komatineni Committed by Thierry Reding
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clk: tegra: Support for OSC context save and restore 



This patch adds support for saving OSC clock frequency and the
drive-strength during OSC clock init and creates an API to restore
OSC control register value from the saved context.

This API is invoked by Tegra210 clock driver during system resume
to restore the  OSC clock settings.

Acked-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent bc0b3a60

drivers/clk/tegra/clk-tegra-fixed.c

+15 −0
Original line number Diff line number Diff line
@@ -17,6 +17,10 @@ 
#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,
@@ -29,6 +33,7 @@ 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)
@@ -96,3 +101,13 @@ void __init tegra_fixed_clk_init(struct tegra_clk *tegra_clks) 
		*dt_clk = clk;

	}

}



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);

}

drivers/clk/tegra/clk.h

+1 −0
Original line number Diff line number Diff line
@@ -829,6 +829,7 @@ u16 tegra_pll_get_fixed_mdiv(struct clk_hw *hw, unsigned long input_rate); 
int tegra_pll_p_div_to_hw(struct tegra_clk_pll *pll, u8 p_div);

int div_frac_get(unsigned long rate, unsigned parent_rate, u8 width,

		 u8 frac_width, u8 flags);

void tegra_clk_osc_resume(void __iomem *clk_base);





/* Combined read fence with delay */

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