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authorGeert Uytterhoeven <geert+renesas@glider.be>2017-06-21 22:51:21 +0200
committerGeert Uytterhoeven <geert+renesas@glider.be>2017-10-20 11:16:05 +0200
commit9f55b17ff6387ab9c4caa9280e2e194bb03ad532 (patch)
treed8eba133be4bcd0b27dedd585106780691d21929 /drivers/clk/renesas
parent9f8c71e5134982cdf8ee35acb204715a2a47ba2e (diff)
downloadlinux-9f55b17ff6387ab9c4caa9280e2e194bb03ad532.tar.bz2
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: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Diffstat (limited to 'drivers/clk/renesas')
-rw-r--r--drivers/clk/renesas/rcar-gen3-cpg.c63
1 files changed, 50 insertions, 13 deletions
diff --git a/drivers/clk/renesas/rcar-gen3-cpg.c b/drivers/clk/renesas/rcar-gen3-cpg.c
index 139985257003..267b5629e3bd 100644
--- a/drivers/clk/renesas/rcar-gen3-cpg.c
+++ b/drivers/clk/renesas/rcar-gen3-cpg.c
@@ -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) {