[PATCH 4/4] pmdomain: renesas: rcar-sysc: Add R-Car M3-W power-off delay quirk

[Geert Uytterhoeven <geert+renesas@glider.be>]

R-Car M3-W needs a delay of 1 µs before powering off the A3IR and A3VC
power domains.  Add support for this using a new flag, which indicates
that a power area is subject to this quirk.

Inspired by a patch in the BSP by Dien Pham.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Changes compared to the BSP:
  - Use a new flag in the SoC-specific area description instead of
    comparing PM Domain names (which applied the quirk to all SoCs),
  - Support for R-Car H3 ES1.x was dropped in v6.4, so it no longer
    needs handling.
---
 drivers/pmdomain/renesas/r8a77960-sysc.c | 6 ++++--
 drivers/pmdomain/renesas/rcar-sysc.c     | 4 ++++
 drivers/pmdomain/renesas/rcar-sysc.h     | 1 +
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/pmdomain/renesas/r8a77960-sysc.c b/drivers/pmdomain/renesas/r8a77960-sysc.c
index e6f2c3f961255f40..2ab3f565d2b0f889 100644
--- a/drivers/pmdomain/renesas/r8a77960-sysc.c
+++ b/drivers/pmdomain/renesas/r8a77960-sysc.c
@@ -32,12 +32,14 @@ static const struct rcar_sysc_area r8a77960_areas[] __initconst = {
 	{ "ca53-cpu3",	0x200, 3, R8A7796_PD_CA53_CPU3,	R8A7796_PD_CA53_SCU,
 	  PD_CPU_NOCR },
 	{ "cr7",	0x240, 0, R8A7796_PD_CR7,	R8A7796_PD_ALWAYS_ON },
-	{ "a3vc",	0x380, 0, R8A7796_PD_A3VC,	R8A7796_PD_ALWAYS_ON },
+	{ "a3vc",	0x380, 0, R8A7796_PD_A3VC,	R8A7796_PD_ALWAYS_ON,
+	  PD_OFF_DELAY },
 	{ "a2vc0",	0x3c0, 0, R8A7796_PD_A2VC0,	R8A7796_PD_A3VC },
 	{ "a2vc1",	0x3c0, 1, R8A7796_PD_A2VC1,	R8A7796_PD_A3VC },
 	{ "3dg-a",	0x100, 0, R8A7796_PD_3DG_A,	R8A7796_PD_ALWAYS_ON },
 	{ "3dg-b",	0x100, 1, R8A7796_PD_3DG_B,	R8A7796_PD_3DG_A },
-	{ "a3ir",	0x180, 0, R8A7796_PD_A3IR,	R8A7796_PD_ALWAYS_ON },
+	{ "a3ir",	0x180, 0, R8A7796_PD_A3IR,	R8A7796_PD_ALWAYS_ON,
+	  PD_OFF_DELAY },
 };
 
 
diff --git a/drivers/pmdomain/renesas/rcar-sysc.c b/drivers/pmdomain/renesas/rcar-sysc.c
index a9d92e38fcee902c..b99326917330f5f1 100644
--- a/drivers/pmdomain/renesas/rcar-sysc.c
+++ b/drivers/pmdomain/renesas/rcar-sysc.c
@@ -90,6 +90,10 @@ static int rcar_sysc_pwr_on_off(const struct rcar_sysc_pd *pd, bool on)
 	if (ret)
 		return -EAGAIN;
 
+	/* Power-off delay quirk */
+	if (!on && (pd->flags & PD_OFF_DELAY))
+		udelay(1);
+
 	/* Submit power shutoff or power resume request */
 	iowrite32(BIT(pd->chan_bit), rcar_sysc_base + pd->chan_offs + reg_offs);
 
diff --git a/drivers/pmdomain/renesas/rcar-sysc.h b/drivers/pmdomain/renesas/rcar-sysc.h
index 8c4ec36ed7da2f9d..07ffce310686b2ce 100644
--- a/drivers/pmdomain/renesas/rcar-sysc.h
+++ b/drivers/pmdomain/renesas/rcar-sysc.h
@@ -16,6 +16,7 @@
 #define PD_CPU		BIT(0)	/* Area contains main CPU core */
 #define PD_SCU		BIT(1)	/* Area contains SCU and L2 cache */
 #define PD_NO_CR	BIT(2)	/* Area lacks PWR{ON,OFF}CR registers */
+#define PD_OFF_DELAY	BIT(3)	/* Area is subject to power-off delay quirk */
 
 #define PD_CPU_CR	PD_CPU		  /* CPU area has CR (R-Car H1) */
 #define PD_CPU_NOCR	PD_CPU | PD_NO_CR /* CPU area lacks CR (R-Car Gen2/3) */
-- 
2.34.1