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path: root/drivers/clk/renesas/renesas-cpg-mssr.c
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Diffstat (limited to 'drivers/clk/renesas/renesas-cpg-mssr.c')
-rw-r--r--drivers/clk/renesas/renesas-cpg-mssr.c105
1 files changed, 103 insertions, 2 deletions
diff --git a/drivers/clk/renesas/renesas-cpg-mssr.c b/drivers/clk/renesas/renesas-cpg-mssr.c
index e580a5e6346c..e3d03ffea4bc 100644
--- a/drivers/clk/renesas/renesas-cpg-mssr.c
+++ b/drivers/clk/renesas/renesas-cpg-mssr.c
@@ -26,6 +26,7 @@
#include <linux/platform_device.h>
#include <linux/pm_clock.h>
#include <linux/pm_domain.h>
+#include <linux/psci.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
@@ -106,6 +107,9 @@ static const u16 srcr[] = {
* @num_core_clks: Number of Core Clocks in clks[]
* @num_mod_clks: Number of Module Clocks in clks[]
* @last_dt_core_clk: ID of the last Core Clock exported to DT
+ * @notifiers: Notifier chain to save/restore clock state for system resume
+ * @smstpcr_saved[].mask: Mask of SMSTPCR[] bits under our control
+ * @smstpcr_saved[].val: Saved values of SMSTPCR[]
*/
struct cpg_mssr_priv {
#ifdef CONFIG_RESET_CONTROLLER
@@ -119,6 +123,12 @@ struct cpg_mssr_priv {
unsigned int num_core_clks;
unsigned int num_mod_clks;
unsigned int last_dt_core_clk;
+
+ struct raw_notifier_head notifiers;
+ struct {
+ u32 mask;
+ u32 val;
+ } smstpcr_saved[ARRAY_SIZE(smstpcr)];
};
@@ -293,7 +303,8 @@ static void __init cpg_mssr_register_core_clk(const struct cpg_core_clk *core,
if (core->type == CLK_TYPE_DIV6P1) {
clk = cpg_div6_register(core->name, 1, &parent_name,
- priv->base + core->offset);
+ priv->base + core->offset,
+ &priv->notifiers);
} else {
clk = clk_register_fixed_factor(NULL, core->name,
parent_name, 0,
@@ -304,7 +315,8 @@ static void __init cpg_mssr_register_core_clk(const struct cpg_core_clk *core,
default:
if (info->cpg_clk_register)
clk = info->cpg_clk_register(dev, core, info,
- priv->clks, priv->base);
+ priv->clks, priv->base,
+ &priv->notifiers);
else
dev_err(dev, "%s has unsupported core clock type %u\n",
core->name, core->type);
@@ -382,6 +394,7 @@ static void __init cpg_mssr_register_mod_clk(const struct mssr_mod_clk *mod,
dev_dbg(dev, "Module clock %pC at %pCr Hz\n", clk, clk);
priv->clks[id] = clk;
+ priv->smstpcr_saved[clock->index / 32].mask |= BIT(clock->index % 32);
return;
fail:
@@ -680,6 +693,12 @@ static const struct of_device_id cpg_mssr_match[] = {
.data = &r8a7796_cpg_mssr_info,
},
#endif
+#ifdef CONFIG_CLK_R8A77970
+ {
+ .compatible = "renesas,r8a77970-cpg-mssr",
+ .data = &r8a77970_cpg_mssr_info,
+ },
+#endif
#ifdef CONFIG_CLK_R8A77995
{
.compatible = "renesas,r8a77995-cpg-mssr",
@@ -694,6 +713,85 @@ static void cpg_mssr_del_clk_provider(void *data)
of_clk_del_provider(data);
}
+#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_ARM_PSCI_FW)
+static int cpg_mssr_suspend_noirq(struct device *dev)
+{
+ struct cpg_mssr_priv *priv = dev_get_drvdata(dev);
+ unsigned int reg;
+
+ /* This is the best we can do to check for the presence of PSCI */
+ if (!psci_ops.cpu_suspend)
+ return 0;
+
+ /* Save module registers with bits under our control */
+ for (reg = 0; reg < ARRAY_SIZE(priv->smstpcr_saved); reg++) {
+ if (priv->smstpcr_saved[reg].mask)
+ priv->smstpcr_saved[reg].val =
+ readl(priv->base + SMSTPCR(reg));
+ }
+
+ /* Save core clocks */
+ raw_notifier_call_chain(&priv->notifiers, PM_EVENT_SUSPEND, NULL);
+
+ return 0;
+}
+
+static int cpg_mssr_resume_noirq(struct device *dev)
+{
+ struct cpg_mssr_priv *priv = dev_get_drvdata(dev);
+ unsigned int reg, i;
+ u32 mask, oldval, newval;
+
+ /* This is the best we can do to check for the presence of PSCI */
+ if (!psci_ops.cpu_suspend)
+ return 0;
+
+ /* Restore core clocks */
+ raw_notifier_call_chain(&priv->notifiers, PM_EVENT_RESUME, NULL);
+
+ /* Restore module clocks */
+ for (reg = 0; reg < ARRAY_SIZE(priv->smstpcr_saved); reg++) {
+ mask = priv->smstpcr_saved[reg].mask;
+ if (!mask)
+ continue;
+
+ oldval = readl(priv->base + SMSTPCR(reg));
+ newval = oldval & ~mask;
+ newval |= priv->smstpcr_saved[reg].val & mask;
+ if (newval == oldval)
+ continue;
+
+ writel(newval, priv->base + SMSTPCR(reg));
+
+ /* Wait until enabled clocks are really enabled */
+ mask &= ~priv->smstpcr_saved[reg].val;
+ if (!mask)
+ continue;
+
+ for (i = 1000; i > 0; --i) {
+ oldval = readl(priv->base + MSTPSR(reg));
+ if (!(oldval & mask))
+ break;
+ cpu_relax();
+ }
+
+ if (!i)
+ dev_warn(dev, "Failed to enable SMSTP %p[0x%x]\n",
+ priv->base + SMSTPCR(reg), oldval & mask);
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops cpg_mssr_pm = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(cpg_mssr_suspend_noirq,
+ cpg_mssr_resume_noirq)
+};
+#define DEV_PM_OPS &cpg_mssr_pm
+#else
+#define DEV_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP && CONFIG_ARM_PSCI_FW */
+
static int __init cpg_mssr_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -729,10 +827,12 @@ static int __init cpg_mssr_probe(struct platform_device *pdev)
if (!clks)
return -ENOMEM;
+ dev_set_drvdata(dev, priv);
priv->clks = clks;
priv->num_core_clks = info->num_total_core_clks;
priv->num_mod_clks = info->num_hw_mod_clks;
priv->last_dt_core_clk = info->last_dt_core_clk;
+ RAW_INIT_NOTIFIER_HEAD(&priv->notifiers);
for (i = 0; i < nclks; i++)
clks[i] = ERR_PTR(-ENOENT);
@@ -769,6 +869,7 @@ static struct platform_driver cpg_mssr_driver = {
.driver = {
.name = "renesas-cpg-mssr",
.of_match_table = cpg_mssr_match,
+ .pm = DEV_PM_OPS,
},
};