Commit d0409631 authored by Dong Aisheng's avatar Dong Aisheng Committed by Shawn Guo
Browse files

clk: imx: scu: add suspend/resume support 



Clock state will be lost when its power domain is completely off
during system suspend/resume. So we save and restore the state
accordingly in suspend/resume callback.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Michael Turquette <mturquette@baylibre.com>
Reviewed-by: default avatarStephen Boyd <sboyd@kernel.org>
Signed-off-by: default avatarDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent 78edeb08

drivers/clk/imx/clk-scu.c

+49 −0
Original line number Diff line number Diff line
@@ -45,6 +45,10 @@ struct clk_scu { 
	struct clk_hw hw;

	u16 rsrc_id;

	u8 clk_type;



	/* for state save&restore */

	bool is_enabled;

	u32 rate;

};



/*
@@ -430,6 +434,9 @@ struct clk_hw *__imx_clk_scu(struct device *dev, const char *name, 
		hw = ERR_PTR(ret);

	}



	if (dev)

		dev_set_drvdata(dev, clk);



	return hw;

}
@@ -486,10 +493,52 @@ static int imx_clk_scu_probe(struct platform_device *pdev) 
	return 0;

}



static int __maybe_unused imx_clk_scu_suspend(struct device *dev)

{

	struct clk_scu *clk = dev_get_drvdata(dev);



	clk->rate = clk_hw_get_rate(&clk->hw);

	clk->is_enabled = clk_hw_is_enabled(&clk->hw);



	if (clk->rate)

		dev_dbg(dev, "save rate %d\n", clk->rate);



	if (clk->is_enabled)

		dev_dbg(dev, "save enabled state\n");



	return 0;

}



static int __maybe_unused imx_clk_scu_resume(struct device *dev)

{

	struct clk_scu *clk = dev_get_drvdata(dev);

	int ret = 0;



	if (clk->rate) {

		ret = clk_scu_set_rate(&clk->hw, clk->rate, 0);

		dev_dbg(dev, "restore rate %d %s\n", clk->rate,

			!ret ? "success" : "failed");

	}



	if (clk->is_enabled) {

		ret = clk_scu_prepare(&clk->hw);

		dev_dbg(dev, "restore enabled state %s\n",

			!ret ? "success" : "failed");

	}



	return ret;

}



static const struct dev_pm_ops imx_clk_scu_pm_ops = {

	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_clk_scu_suspend,

				      imx_clk_scu_resume)

};



static struct platform_driver imx_clk_scu_driver = {

	.driver = {

		.name = "imx-scu-clk",

		.suppress_bind_attrs = true,

		.pm = &imx_clk_scu_pm_ops,

	},

	.probe = imx_clk_scu_probe,

};