[PATCH] ram: stm32mp1: Conditionally enable ASR

[Marek Vasut]

Enable DRAM ASR, auto self-refresh, conditionally, based on DT property
"st,mem-enable-asr" . While ASR does save considerable amount of power
at runtime automatically, it also causes LTDC underruns on large panels.
Let user select whether or not ASR is required or not, generally ASR
should be enabled on portable and battery operated devices.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
Cc: Patrice Chotard <patrice.chotard at foss.st.com>
---
 drivers/ram/stm32mp1/stm32mp1_ddr.c | 3 ++-
 drivers/ram/stm32mp1/stm32mp1_ddr.h | 1 +
 drivers/ram/stm32mp1/stm32mp1_ram.c | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.c b/drivers/ram/stm32mp1/stm32mp1_ddr.c
index 528a171b454..fd11e02aff4 100644
--- a/drivers/ram/stm32mp1/stm32mp1_ddr.c
+++ b/drivers/ram/stm32mp1/stm32mp1_ddr.c
@@ -845,7 +845,8 @@ start:
 				 config->c_reg.pwrctl);
 
 /* Enable auto-self-refresh, which saves a bit of power at runtime. */
-	stm32mp1_asr_enable(priv);
+	if (config->info.enable_asr)
+		stm32mp1_asr_enable(priv);
 
 	/* enable uMCTL2 AXI port 0 and 1 */
 	setbits_le32(&priv->ctl->pctrl_0, DDRCTRL_PCTRL_N_PORT_EN);
diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.h b/drivers/ram/stm32mp1/stm32mp1_ddr.h
index 861efff92be..c74a9cea2cc 100644
--- a/drivers/ram/stm32mp1/stm32mp1_ddr.h
+++ b/drivers/ram/stm32mp1/stm32mp1_ddr.h
@@ -144,6 +144,7 @@ struct stm32mp1_ddr_info {
 	const char *name;
 	u32 speed; /* in kHZ */
 	u32 size;  /* memory size in byte = col * row * width */
+	bool enable_asr;
 };
 
 struct stm32mp1_ddr_config {
diff --git a/drivers/ram/stm32mp1/stm32mp1_ram.c b/drivers/ram/stm32mp1/stm32mp1_ram.c
index 49b1262461b..f39cfad4764 100644
--- a/drivers/ram/stm32mp1/stm32mp1_ram.c
+++ b/drivers/ram/stm32mp1/stm32mp1_ram.c
@@ -122,6 +122,7 @@ static int stm32mp1_ddr_setup(struct udevice *dev)
 	config.info.speed = ofnode_read_u32_default(node, "st,mem-speed", 0);
 	config.info.size = ofnode_read_u32_default(node, "st,mem-size", 0);
 	config.info.name = ofnode_read_string(node, "st,mem-name");
+	config.info.enable_asr = ofnode_read_bool(node, "st,mem-enable-asr");
 	if (!config.info.name) {
 		dev_dbg(dev, "no st,mem-name\n");
 		return -EINVAL;
-- 
2.35.1