clk: at91: re-factor clocks suspend/resume

SAMA5D2 and SAMA7G5 have a special power saving mode (backup mode) where most of the SoC's components are powered off (including PMC). Resuming from this mode is done with the help of bootloader. Peripherals are not aware of the power saving mode thus most of them are disabling clocks in proper suspend API and re-enable them in resume API without taking into account the previously setup rate. Moreover some of the peripherals are acting as wakeup sources and are not disabling the clocks in this scenario, when suspending. Since backup mode cuts the power for peripherals, in resume part these clocks needs to be re-configured. The initial PMC suspend/resume code was designed only for SAMA5D2's PMC (as it was the only one supporting backup mode). SAMA7G supports also backup mode and its PMC is different (few new functionalities, different registers offsets, different offsets in registers for each functionalities). To address both SAMA5D2 and SAMA7G5 PMC add .save_context()/.resume_context() support to each clocks driver and call this from PMC driver. Signed-off-by: Claudiu Beznea <[email protected]> Link: https://lore.kernel.org/r/[email protected] Acked-by: Nicolas Ferre <[email protected]> Signed-off-by: Stephen Boyd <[email protected]>
ashr · Oct 27, 2021 · 3697156 · 3697156
1 parent c405f5c
commit 3697156
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Showing 12 changed files with 558 additions and 181 deletions.
diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
@@ -27,32 +27,43 @@ struct clk_generated {
 	u32 id;
 	u32 gckdiv;
 	const struct clk_pcr_layout *layout;
+	struct at91_clk_pms pms;
 	u8 parent_id;
 	int chg_pid;
 };
 
 #define to_clk_generated(hw) \
 	container_of(hw, struct clk_generated, hw)
 
-static int clk_generated_enable(struct clk_hw *hw)
+static int clk_generated_set(struct clk_generated *gck, int status)
 {
-	struct clk_generated *gck = to_clk_generated(hw);
 	unsigned long flags;
-
-	pr_debug("GCLK: %s, gckdiv = %d, parent id = %d\n",
-		 __func__, gck->gckdiv, gck->parent_id);
+	unsigned int enable = status ? AT91_PMC_PCR_GCKEN : 0;
 
 	spin_lock_irqsave(gck->lock, flags);
 	regmap_write(gck->regmap, gck->layout->offset,
 		     (gck->id & gck->layout->pid_mask));
 	regmap_update_bits(gck->regmap, gck->layout->offset,
 			   AT91_PMC_PCR_GCKDIV_MASK | gck->layout->gckcss_mask |
-			   gck->layout->cmd | AT91_PMC_PCR_GCKEN,
+			   gck->layout->cmd | enable,
 			   field_prep(gck->layout->gckcss_mask, gck->parent_id) |
 			   gck->layout->cmd |
 			   FIELD_PREP(AT91_PMC_PCR_GCKDIV_MASK, gck->gckdiv) |
-			   AT91_PMC_PCR_GCKEN);
+			   enable);
 	spin_unlock_irqrestore(gck->lock, flags);
+
+	return 0;
+}
+
+static int clk_generated_enable(struct clk_hw *hw)
+{
+	struct clk_generated *gck = to_clk_generated(hw);
+
+	pr_debug("GCLK: %s, gckdiv = %d, parent id = %d\n",
+		 __func__, gck->gckdiv, gck->parent_id);
+
+	clk_generated_set(gck, 1);
+
 	return 0;
 }
 
@@ -245,6 +256,23 @@ static int clk_generated_set_rate(struct clk_hw *hw,
 	return 0;
 }
 
+static int clk_generated_save_context(struct clk_hw *hw)
+{
+	struct clk_generated *gck = to_clk_generated(hw);
+
+	gck->pms.status = clk_generated_is_enabled(&gck->hw);
+
+	return 0;
+}
+
+static void clk_generated_restore_context(struct clk_hw *hw)
+{
+	struct clk_generated *gck = to_clk_generated(hw);
+
+	if (gck->pms.status)
+		clk_generated_set(gck, gck->pms.status);
+}
+
 static const struct clk_ops generated_ops = {
 	.enable = clk_generated_enable,
 	.disable = clk_generated_disable,
@@ -254,6 +282,8 @@ static const struct clk_ops generated_ops = {
 	.get_parent = clk_generated_get_parent,
 	.set_parent = clk_generated_set_parent,
 	.set_rate = clk_generated_set_rate,
+	.save_context = clk_generated_save_context,
+	.restore_context = clk_generated_restore_context,
 };
 
 /**
@@ -320,8 +350,6 @@ at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
 	if (ret) {
 		kfree(gck);
 		hw = ERR_PTR(ret);
-	} else {
-		pmc_register_id(id);
 	}
 
 	return hw;

diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c
@@ -28,6 +28,7 @@
 struct clk_main_osc {
 	struct clk_hw hw;
 	struct regmap *regmap;
+	struct at91_clk_pms pms;
 };
 
 #define to_clk_main_osc(hw) container_of(hw, struct clk_main_osc, hw)
@@ -37,6 +38,7 @@ struct clk_main_rc_osc {
 	struct regmap *regmap;
 	unsigned long frequency;
 	unsigned long accuracy;
+	struct at91_clk_pms pms;
 };
 
 #define to_clk_main_rc_osc(hw) container_of(hw, struct clk_main_rc_osc, hw)
@@ -51,6 +53,7 @@ struct clk_rm9200_main {
 struct clk_sam9x5_main {
 	struct clk_hw hw;
 	struct regmap *regmap;
+	struct at91_clk_pms pms;
 	u8 parent;
 };
 
@@ -120,10 +123,29 @@ static int clk_main_osc_is_prepared(struct clk_hw *hw)
 	return (status & AT91_PMC_MOSCS) && clk_main_parent_select(tmp);
 }
 
+static int clk_main_osc_save_context(struct clk_hw *hw)
+{
+	struct clk_main_osc *osc = to_clk_main_osc(hw);
+
+	osc->pms.status = clk_main_osc_is_prepared(hw);
+
+	return 0;
+}
+
+static void clk_main_osc_restore_context(struct clk_hw *hw)
+{
+	struct clk_main_osc *osc = to_clk_main_osc(hw);
+
+	if (osc->pms.status)
+		clk_main_osc_prepare(hw);
+}
+
 static const struct clk_ops main_osc_ops = {
 	.prepare = clk_main_osc_prepare,
 	.unprepare = clk_main_osc_unprepare,
 	.is_prepared = clk_main_osc_is_prepared,
+	.save_context = clk_main_osc_save_context,
+	.restore_context = clk_main_osc_restore_context,
 };
 
 struct clk_hw * __init
@@ -240,12 +262,31 @@ static unsigned long clk_main_rc_osc_recalc_accuracy(struct clk_hw *hw,
 	return osc->accuracy;
 }
 
+static int clk_main_rc_osc_save_context(struct clk_hw *hw)
+{
+	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
+
+	osc->pms.status = clk_main_rc_osc_is_prepared(hw);
+
+	return 0;
+}
+
+static void clk_main_rc_osc_restore_context(struct clk_hw *hw)
+{
+	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
+
+	if (osc->pms.status)
+		clk_main_rc_osc_prepare(hw);
+}
+
 static const struct clk_ops main_rc_osc_ops = {
 	.prepare = clk_main_rc_osc_prepare,
 	.unprepare = clk_main_rc_osc_unprepare,
 	.is_prepared = clk_main_rc_osc_is_prepared,
 	.recalc_rate = clk_main_rc_osc_recalc_rate,
 	.recalc_accuracy = clk_main_rc_osc_recalc_accuracy,
+	.save_context = clk_main_rc_osc_save_context,
+	.restore_context = clk_main_rc_osc_restore_context,
 };
 
 struct clk_hw * __init
@@ -465,12 +506,37 @@ static u8 clk_sam9x5_main_get_parent(struct clk_hw *hw)
 	return clk_main_parent_select(status);
 }
 
+static int clk_sam9x5_main_save_context(struct clk_hw *hw)
+{
+	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
+
+	clkmain->pms.status = clk_main_rc_osc_is_prepared(&clkmain->hw);
+	clkmain->pms.parent = clk_sam9x5_main_get_parent(&clkmain->hw);
+
+	return 0;
+}
+
+static void clk_sam9x5_main_restore_context(struct clk_hw *hw)
+{
+	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
+	int ret;
+
+	ret = clk_sam9x5_main_set_parent(hw, clkmain->pms.parent);
+	if (ret)
+		return;
+
+	if (clkmain->pms.status)
+		clk_sam9x5_main_prepare(hw);
+}
+
 static const struct clk_ops sam9x5_main_ops = {
 	.prepare = clk_sam9x5_main_prepare,
 	.is_prepared = clk_sam9x5_main_is_prepared,
 	.recalc_rate = clk_sam9x5_main_recalc_rate,
 	.set_parent = clk_sam9x5_main_set_parent,
 	.get_parent = clk_sam9x5_main_get_parent,
+	.save_context = clk_sam9x5_main_save_context,
+	.restore_context = clk_sam9x5_main_restore_context,
 };
 
 struct clk_hw * __init