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

From: Geert Uytterhoeven
Date: Wed Apr 17 2024 - 06:31:42 EST


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@xxxxxxxxx>
---
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