[PATCH AUTOSEL 6.17-6.12] clk: at91: sam9x7: Add peripheral clock id for pmecc

[Sasha Levin <sashal@kernel.org>]

From: Balamanikandan Gunasundar <balamanikandan.gunasundar@microchip.com>

[ Upstream commit 94a1274100e397a27361ae53ace37be6da42a079 ]

Add pmecc instance id in peripheral clock description.

Signed-off-by: Balamanikandan Gunasundar <balamanikandan.gunasundar@microchip.com>
Link: https://lore.kernel.org/r/20250909103817.49334-1-balamanikandan.gunasundar@microchip.com
[claudiu.beznea@tuxon.dev: use tabs instead of spaces]
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

YES – the fix should go to stable.

- `drivers/clk/at91/sam9x7.c:411` now lists the PMC peripheral clock
  slot for the PMECC block (ID 48). This table drives the loop in
  `sam9x7_pmc_setup()` that registers every peripheral clock with the
  framework (`drivers/clk/at91/sam9x7.c:889-904`). Without the entry, no
  `clk_hw` is created for ID 48, so any DT request such as `clocks =
  <&pmc PMC_TYPE_PERIPHERAL 48>` fails at probe time with `-ENOENT`,
  leaving the PMECC clock gated.
- On Microchip/Atmel SoCs, peripheral clocks power up disabled. The
  PMECC driver programs and polls the engine via MMIO
  (`drivers/mtd/nand/raw/atmel/pmecc.c:843-870`); if the clock stays
  off, register writes and the ready poll (`readl_relaxed_poll_timeout`)
  never complete, which causes ECC operations to time out and the NAND
  subsystem to fail.
- The SAM9X7 DT already exposes the PMECC device
  (`arch/arm/boot/dts/microchip/sam9x7.dtsi:1132-1134`), so enabling
  NAND with ECC depends on the clock being reachable. The patch is a
  one-line data addition with no behavioural impact outside supplying
  the missing clock, making the backport low-risk and clearly bug-fixing
  for users relying on PMECC.

 drivers/clk/at91/sam9x7.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/at91/sam9x7.c b/drivers/clk/at91/sam9x7.c
index 7322220418b45..89868a0aeaba9 100644
--- a/drivers/clk/at91/sam9x7.c
+++ b/drivers/clk/at91/sam9x7.c
@@ -408,6 +408,7 @@ static const struct {
 	{ .n = "pioD_clk",	.id = 44, },
 	{ .n = "tcb1_clk",	.id = 45, },
 	{ .n = "dbgu_clk",	.id = 47, },
+	{ .n = "pmecc_clk",	.id = 48, },
 	/*
 	 * mpddr_clk feeds DDR controller and is enabled by bootloader thus we
 	 * need to keep it enabled in case there is no Linux consumer for it.
-- 
2.51.0