Commit 2b8cfd6b authored by Sowjanya Komatineni's avatar Sowjanya Komatineni Committed by Thierry Reding
Browse files

clk: tegra: periph: Add restore_context support 



This patch implements restore_context support for clk-periph and
clk-sdmmc-mux clock operations to restore clock parent and rates
on system resume.

During system suspend, core power goes off and looses the context
of the Tegra clock controller registers.

So on system resume, clocks parent and rate are restored back to
the context before suspend based on cached data.

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 50d4da9b

drivers/clk/tegra/clk-periph.c

+21 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.

 */



#include <linux/clk.h>

#include <linux/clk-provider.h>

#include <linux/export.h>

#include <linux/slab.h>
@@ -99,6 +100,23 @@ static void clk_periph_disable(struct clk_hw *hw) 
	gate_ops->disable(gate_hw);

}



static void clk_periph_restore_context(struct clk_hw *hw)

{

	struct tegra_clk_periph *periph = to_clk_periph(hw);

	const struct clk_ops *div_ops = periph->div_ops;

	struct clk_hw *div_hw = &periph->divider.hw;

	int parent_id;



	parent_id = clk_hw_get_parent_index(hw);

	if (WARN_ON(parent_id < 0))

		return;



	if (!(periph->gate.flags & TEGRA_PERIPH_NO_DIV))

		div_ops->restore_context(div_hw);



	clk_periph_set_parent(hw, parent_id);

}



const struct clk_ops tegra_clk_periph_ops = {

	.get_parent = clk_periph_get_parent,

	.set_parent = clk_periph_set_parent,
@@ -108,6 +126,7 @@ const struct clk_ops tegra_clk_periph_ops = { 
	.is_enabled = clk_periph_is_enabled,

	.enable = clk_periph_enable,

	.disable = clk_periph_disable,

	.restore_context = clk_periph_restore_context,

};



static const struct clk_ops tegra_clk_periph_nodiv_ops = {
@@ -116,6 +135,7 @@ static const struct clk_ops tegra_clk_periph_nodiv_ops = { 
	.is_enabled = clk_periph_is_enabled,

	.enable = clk_periph_enable,

	.disable = clk_periph_disable,

	.restore_context = clk_periph_restore_context,

};



static const struct clk_ops tegra_clk_periph_no_gate_ops = {
@@ -124,6 +144,7 @@ static const struct clk_ops tegra_clk_periph_no_gate_ops = { 
	.recalc_rate = clk_periph_recalc_rate,

	.round_rate = clk_periph_round_rate,

	.set_rate = clk_periph_set_rate,

	.restore_context = clk_periph_restore_context,

};



static struct clk *_tegra_clk_register_periph(const char *name,

drivers/clk/tegra/clk-sdmmc-mux.c

+16 −0
Original line number Diff line number Diff line
@@ -194,6 +194,21 @@ static void clk_sdmmc_mux_disable(struct clk_hw *hw) 
	gate_ops->disable(gate_hw);

}



static void clk_sdmmc_mux_restore_context(struct clk_hw *hw)

{

	struct clk_hw *parent = clk_hw_get_parent(hw);

	unsigned long parent_rate = clk_hw_get_rate(parent);

	unsigned long rate = clk_hw_get_rate(hw);

	int parent_id;



	parent_id = clk_hw_get_parent_index(hw);

	if (WARN_ON(parent_id < 0))

		return;



	clk_sdmmc_mux_set_parent(hw, parent_id);

	clk_sdmmc_mux_set_rate(hw, rate, parent_rate);

}



static const struct clk_ops tegra_clk_sdmmc_mux_ops = {

	.get_parent = clk_sdmmc_mux_get_parent,

	.set_parent = clk_sdmmc_mux_set_parent,
@@ -203,6 +218,7 @@ static const struct clk_ops tegra_clk_sdmmc_mux_ops = { 
	.is_enabled = clk_sdmmc_mux_is_enabled,

	.enable = clk_sdmmc_mux_enable,

	.disable = clk_sdmmc_mux_disable,

	.restore_context = clk_sdmmc_mux_restore_context,

};



struct clk *tegra_clk_register_sdmmc_mux_div(const char *name,

CRA Git | Maintained and supported by SUSTech CRA and CCSE