[PATCH AUTOSEL 6.17] clk: at91: add ACR in all PLL settings

Sasha Levin sashal at kernel.org
Sun Oct 26 07:48:53 PDT 2025


From: Cristian Birsan <cristian.birsan at microchip.com>

[ Upstream commit bfa2bddf6ffe0ac034d02cda20c74ef05571210e ]

Add the ACR register to all PLL settings and provide the correct
ACR value for each PLL used in different SoCs.

Suggested-by: Mihai Sain <mihai.sain at microchip.com>
Signed-off-by: Cristian Birsan <cristian.birsan at microchip.com>
[nicolas.ferre at microchip.com: add sama7d65 and review commit message]
Signed-off-by: Nicolas Ferre <nicolas.ferre at microchip.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---

LLM Generated explanations, may be completely bogus:

YES – this patch is a low-risk dependency that stable trees need before
they can pick up the actual bug fix for the Atmel/Microchip PLL driver.

- `drivers/clk/at91/clk-sam9x60-pll.c:107` (from the follow-up fix) now
  reads `core->characteristics->acr`; without this commit the field is
  absent/zero, so the driver would push an invalid value into
  PMC_PLL_ACR.
- This change extends `struct clk_pll_characteristics` with an explicit
  `acr` slot (`drivers/clk/at91/pmc.h:83`) and populates per-SoC values
  for every platform that feeds the sam9x60-style PLL driver: sam9x60
  (`drivers/clk/at91/sam9x60.c:39` and `:52`), sam9x7
  (`drivers/clk/at91/sam9x7.c:110`/`119`/`127`/`135`/`143`), sama7d65
  (`drivers/clk/at91/sama7d65.c:141`/`150`/`158`/`166`), and sama7g5
  (`drivers/clk/at91/sama7g5.c:116`/`125`).
- The new constants differ from the old hard-coded defaults (e.g.
  sama7*d* CPU PLLs need `0x00070010` instead of `0x00020010`), so once
  the driver starts using `characteristics->acr` the hardware finally
  receives the correct analog-control parameters.
- The struct growth is internal to the driver, and all in-tree users
  either get an explicit initializer (updated here) or safely default to
  zero, so the risk to stable is negligible.

Follow-up: backport `ARM: at91: remove default values for PMC_PLL_ACR`
(e204c148c83025205eaf9be89593edf350d327a0) right after this so the
stored ACR values are actually written.

 drivers/clk/at91/pmc.h      | 1 +
 drivers/clk/at91/sam9x60.c  | 2 ++
 drivers/clk/at91/sam9x7.c   | 5 +++++
 drivers/clk/at91/sama7d65.c | 4 ++++
 drivers/clk/at91/sama7g5.c  | 2 ++
 5 files changed, 14 insertions(+)

diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 4fb29ca111f7d..5daa32c4cf254 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -80,6 +80,7 @@ struct clk_pll_characteristics {
 	u16 *icpll;
 	u8 *out;
 	u8 upll : 1;
+	u32 acr;
 };
 
 struct clk_programmable_layout {
diff --git a/drivers/clk/at91/sam9x60.c b/drivers/clk/at91/sam9x60.c
index db6db9e2073eb..18baf4a256f47 100644
--- a/drivers/clk/at91/sam9x60.c
+++ b/drivers/clk/at91/sam9x60.c
@@ -36,6 +36,7 @@ static const struct clk_pll_characteristics plla_characteristics = {
 	.num_output = ARRAY_SIZE(plla_outputs),
 	.output = plla_outputs,
 	.core_output = core_outputs,
+	.acr = UL(0x00020010),
 };
 
 static const struct clk_range upll_outputs[] = {
@@ -48,6 +49,7 @@ static const struct clk_pll_characteristics upll_characteristics = {
 	.output = upll_outputs,
 	.core_output = core_outputs,
 	.upll = true,
+	.acr = UL(0x12023010), /* fIN = [18 MHz, 32 MHz]*/
 };
 
 static const struct clk_pll_layout pll_frac_layout = {
diff --git a/drivers/clk/at91/sam9x7.c b/drivers/clk/at91/sam9x7.c
index ffab32b047a01..7322220418b45 100644
--- a/drivers/clk/at91/sam9x7.c
+++ b/drivers/clk/at91/sam9x7.c
@@ -107,6 +107,7 @@ static const struct clk_pll_characteristics plla_characteristics = {
 	.num_output = ARRAY_SIZE(plla_outputs),
 	.output = plla_outputs,
 	.core_output = plla_core_outputs,
+	.acr = UL(0x00020010), /* Old ACR_DEFAULT_PLLA value */
 };
 
 static const struct clk_pll_characteristics upll_characteristics = {
@@ -115,6 +116,7 @@ static const struct clk_pll_characteristics upll_characteristics = {
 	.output = upll_outputs,
 	.core_output = upll_core_outputs,
 	.upll = true,
+	.acr = UL(0x12023010), /* fIN=[20 MHz, 32 MHz] */
 };
 
 static const struct clk_pll_characteristics lvdspll_characteristics = {
@@ -122,6 +124,7 @@ static const struct clk_pll_characteristics lvdspll_characteristics = {
 	.num_output = ARRAY_SIZE(lvdspll_outputs),
 	.output = lvdspll_outputs,
 	.core_output = lvdspll_core_outputs,
+	.acr = UL(0x12023010), /* fIN=[20 MHz, 32 MHz] */
 };
 
 static const struct clk_pll_characteristics audiopll_characteristics = {
@@ -129,6 +132,7 @@ static const struct clk_pll_characteristics audiopll_characteristics = {
 	.num_output = ARRAY_SIZE(audiopll_outputs),
 	.output = audiopll_outputs,
 	.core_output = audiopll_core_outputs,
+	.acr = UL(0x12023010), /* fIN=[20 MHz, 32 MHz] */
 };
 
 static const struct clk_pll_characteristics plladiv2_characteristics = {
@@ -136,6 +140,7 @@ static const struct clk_pll_characteristics plladiv2_characteristics = {
 	.num_output = ARRAY_SIZE(plladiv2_outputs),
 	.output = plladiv2_outputs,
 	.core_output = plladiv2_core_outputs,
+	.acr = UL(0x00020010),  /* Old ACR_DEFAULT_PLLA value */
 };
 
 /* Layout for fractional PLL ID PLLA. */
diff --git a/drivers/clk/at91/sama7d65.c b/drivers/clk/at91/sama7d65.c
index a5d40df8b2f27..7dee2b160ffb3 100644
--- a/drivers/clk/at91/sama7d65.c
+++ b/drivers/clk/at91/sama7d65.c
@@ -138,6 +138,7 @@ static const struct clk_pll_characteristics cpu_pll_characteristics = {
 	.num_output = ARRAY_SIZE(cpu_pll_outputs),
 	.output = cpu_pll_outputs,
 	.core_output = core_outputs,
+	.acr = UL(0x00070010),
 };
 
 /* PLL characteristics. */
@@ -146,6 +147,7 @@ static const struct clk_pll_characteristics pll_characteristics = {
 	.num_output = ARRAY_SIZE(pll_outputs),
 	.output = pll_outputs,
 	.core_output = core_outputs,
+	.acr = UL(0x00070010),
 };
 
 static const struct clk_pll_characteristics lvdspll_characteristics = {
@@ -153,6 +155,7 @@ static const struct clk_pll_characteristics lvdspll_characteristics = {
 	.num_output = ARRAY_SIZE(lvdspll_outputs),
 	.output = lvdspll_outputs,
 	.core_output = lvdspll_core_outputs,
+	.acr = UL(0x00070010),
 };
 
 static const struct clk_pll_characteristics upll_characteristics = {
@@ -160,6 +163,7 @@ static const struct clk_pll_characteristics upll_characteristics = {
 	.num_output = ARRAY_SIZE(upll_outputs),
 	.output = upll_outputs,
 	.core_output = upll_core_outputs,
+	.acr = UL(0x12020010),
 	.upll = true,
 };
 
diff --git a/drivers/clk/at91/sama7g5.c b/drivers/clk/at91/sama7g5.c
index 8385badc1c706..1340c2b006192 100644
--- a/drivers/clk/at91/sama7g5.c
+++ b/drivers/clk/at91/sama7g5.c
@@ -113,6 +113,7 @@ static const struct clk_pll_characteristics cpu_pll_characteristics = {
 	.num_output = ARRAY_SIZE(cpu_pll_outputs),
 	.output = cpu_pll_outputs,
 	.core_output = core_outputs,
+	.acr = UL(0x00070010),
 };
 
 /* PLL characteristics. */
@@ -121,6 +122,7 @@ static const struct clk_pll_characteristics pll_characteristics = {
 	.num_output = ARRAY_SIZE(pll_outputs),
 	.output = pll_outputs,
 	.core_output = core_outputs,
+	.acr = UL(0x00070010),
 };
 
 /*
-- 
2.51.0




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