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Commit 9f55b17f authored by Geert Uytterhoeven's avatar Geert Uytterhoeven
Browse files

clk: renesas: rcar-gen3: Restore SDHI clocks during resume 



On R-Car Gen3 systems, PSCI system suspend powers down the SoC, losing
clock configuration.  Register a notifier to save/restore SDHI clock
registers during system suspend/resume.

This is implemented using the cpg_simple_notifier abstraction, which can
be reused for others clocks that just need to save/restore a single
register.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: default avatarNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
parent 9f8c71e5

drivers/clk/renesas/rcar-gen3-cpg.c

+50 −13
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/err.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/pm.h>

#include <linux/slab.h>

#include <linux/sys_soc.h>
@@ -29,6 +30,36 @@ 
#define CPG_PLL2CR		0x002c

#define CPG_PLL4CR		0x01f4



struct cpg_simple_notifier {

	struct notifier_block nb;

	void __iomem *reg;

	u32 saved;

};



static int cpg_simple_notifier_call(struct notifier_block *nb,

				    unsigned long action, void *data)

{

	struct cpg_simple_notifier *csn =

		container_of(nb, struct cpg_simple_notifier, nb);



	switch (action) {

	case PM_EVENT_SUSPEND:

		csn->saved = readl(csn->reg);

		return NOTIFY_OK;



	case PM_EVENT_RESUME:

		writel(csn->saved, csn->reg);

		return NOTIFY_OK;

	}

	return NOTIFY_DONE;

}



static void cpg_simple_notifier_register(struct raw_notifier_head *notifiers,

					 struct cpg_simple_notifier *csn)

{

	csn->nb.notifier_call = cpg_simple_notifier_call;

	raw_notifier_chain_register(notifiers, &csn->nb);

}



/*

 * SDn Clock
@@ -55,8 +86,8 @@ struct sd_div_table { 


struct sd_clock {

	struct clk_hw hw;

	void __iomem *reg;

	const struct sd_div_table *div_table;

	struct cpg_simple_notifier csn;

	unsigned int div_num;

	unsigned int div_min;

	unsigned int div_max;
@@ -97,12 +128,12 @@ static const struct sd_div_table cpg_sd_div_table[] = { 
static int cpg_sd_clock_enable(struct clk_hw *hw)

{

	struct sd_clock *clock = to_sd_clock(hw);

	u32 val = readl(clock->reg);

	u32 val = readl(clock->csn.reg);



	val &= ~(CPG_SD_STP_MASK);

	val |= clock->div_table[clock->cur_div_idx].val & CPG_SD_STP_MASK;



	writel(val, clock->reg);

	writel(val, clock->csn.reg);



	return 0;

}
@@ -111,14 +142,14 @@ static void cpg_sd_clock_disable(struct clk_hw *hw) 
{

	struct sd_clock *clock = to_sd_clock(hw);



	writel(readl(clock->reg) | CPG_SD_STP_MASK, clock->reg);

	writel(readl(clock->csn.reg) | CPG_SD_STP_MASK, clock->csn.reg);

}



static int cpg_sd_clock_is_enabled(struct clk_hw *hw)

{

	struct sd_clock *clock = to_sd_clock(hw);



	return !(readl(clock->reg) & CPG_SD_STP_MASK);

	return !(readl(clock->csn.reg) & CPG_SD_STP_MASK);

}



static unsigned long cpg_sd_clock_recalc_rate(struct clk_hw *hw,
@@ -170,10 +201,10 @@ static int cpg_sd_clock_set_rate(struct clk_hw *hw, unsigned long rate, 


	clock->cur_div_idx = i;



	val = readl(clock->reg);

	val = readl(clock->csn.reg);

	val &= ~(CPG_SD_STP_MASK | CPG_SD_FC_MASK);

	val |= clock->div_table[i].val & (CPG_SD_STP_MASK | CPG_SD_FC_MASK);

	writel(val, clock->reg);

	writel(val, clock->csn.reg);



	return 0;

}
@@ -188,8 +219,8 @@ static const struct clk_ops cpg_sd_clock_ops = { 
};



static struct clk * __init cpg_sd_clk_register(const struct cpg_core_clk *core,

					       void __iomem *base,

					       const char *parent_name)

	void __iomem *base, const char *parent_name,

	struct raw_notifier_head *notifiers)

{

	struct clk_init_data init;

	struct sd_clock *clock;
@@ -207,12 +238,12 @@ static struct clk * __init cpg_sd_clk_register(const struct cpg_core_clk *core, 
	init.parent_names = &parent_name;

	init.num_parents = 1;



	clock->reg = base + core->offset;

	clock->csn.reg = base + core->offset;

	clock->hw.init = &init;

	clock->div_table = cpg_sd_div_table;

	clock->div_num = ARRAY_SIZE(cpg_sd_div_table);



	sd_fc = readl(clock->reg) & CPG_SD_FC_MASK;

	sd_fc = readl(clock->csn.reg) & CPG_SD_FC_MASK;

	for (i = 0; i < clock->div_num; i++)

		if (sd_fc == (clock->div_table[i].val & CPG_SD_FC_MASK))

			break;
@@ -233,8 +264,13 @@ static struct clk * __init cpg_sd_clk_register(const struct cpg_core_clk *core, 


	clk = clk_register(NULL, &clock->hw);

	if (IS_ERR(clk))

		kfree(clock);

		goto free_clock;



	cpg_simple_notifier_register(notifiers, &clock->csn);

	return clk;



free_clock:

	kfree(clock);

	return clk;

}
@@ -332,7 +368,8 @@ struct clk * __init rcar_gen3_cpg_clk_register(struct device *dev, 
		break;



	case CLK_TYPE_GEN3_SD:

		return cpg_sd_clk_register(core, base, __clk_get_name(parent));

		return cpg_sd_clk_register(core, base, __clk_get_name(parent),

					   notifiers);



	case CLK_TYPE_GEN3_R:

		if (cpg_quirks & RCKCR_CKSEL) {