[PATCH v3 2/4] aspeed/scu: Fix W1C behavior

From: Joel Stanley <joel@jms.id.au>
To: "Peter Maydell" <peter.maydell@linaro.org>,
	"Cédric Le Goater" <clg@kaod.org>
Cc: "Andrew Jeffery" <andrew@aj.id.au>,
	qemu-arm@nongnu.org, "Alex Bennée" <alex.bennee@linaro.org>,
	qemu-devel@nongnu.org
Subject: [PATCH v3 2/4] aspeed/scu: Fix W1C behavior
Date: Thu, 14 Nov 2019 08:42:59 +1030	[thread overview]
Message-ID: <20191113221301.8768-3-joel@jms.id.au> (raw)
In-Reply-To: <20191113221301.8768-1-joel@jms.id.au>

This models the clock write one to clear registers, and fixes up some
incorrect behavior in all of the write to clear registers.

There was also a typo in one of the register definitions.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v3: Beef up the comments
---
 hw/misc/aspeed_scu.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/hw/misc/aspeed_scu.c b/hw/misc/aspeed_scu.c
index 717509bc5460..5518168e48b4 100644
--- a/hw/misc/aspeed_scu.c
+++ b/hw/misc/aspeed_scu.c
@@ -98,7 +98,7 @@
 #define AST2600_CLK_STOP_CTRL     TO_REG(0x80)
 #define AST2600_CLK_STOP_CTRL_CLR TO_REG(0x84)
 #define AST2600_CLK_STOP_CTRL2     TO_REG(0x90)
-#define AST2600_CLK_STOP_CTR2L_CLR TO_REG(0x94)
+#define AST2600_CLK_STOP_CTRL2_CLR TO_REG(0x94)
 #define AST2600_SDRAM_HANDSHAKE   TO_REG(0x100)
 #define AST2600_HPLL_PARAM        TO_REG(0x200)
 #define AST2600_HPLL_EXT          TO_REG(0x204)
@@ -532,11 +532,13 @@ static uint64_t aspeed_ast2600_scu_read(void *opaque, hwaddr offset,
     return s->regs[reg];
 }
 
-static void aspeed_ast2600_scu_write(void *opaque, hwaddr offset, uint64_t data,
+static void aspeed_ast2600_scu_write(void *opaque, hwaddr offset, uint64_t data64,
                                      unsigned size)
 {
     AspeedSCUState *s = ASPEED_SCU(opaque);
     int reg = TO_REG(offset);
+    /* Truncate here so bitwise operations below behave as expected */
+    uint32_t data = data64;
 
     if (reg >= ASPEED_AST2600_SCU_NR_REGS) {
         qemu_log_mask(LOG_GUEST_ERROR,
@@ -563,15 +565,20 @@ static void aspeed_ast2600_scu_write(void *opaque, hwaddr offset, uint64_t data,
         /* fall through */
     case AST2600_SYS_RST_CTRL:
     case AST2600_SYS_RST_CTRL2:
+    case AST2600_CLK_STOP_CTRL:
+    case AST2600_CLK_STOP_CTRL2:
         /* W1S (Write 1 to set) registers */
         s->regs[reg] |= data;
         return;
     case AST2600_SYS_RST_CTRL_CLR:
     case AST2600_SYS_RST_CTRL2_CLR:
+    case AST2600_CLK_STOP_CTRL_CLR:
+    case AST2600_CLK_STOP_CTRL2_CLR:
     case AST2600_HW_STRAP1_CLR:
     case AST2600_HW_STRAP2_CLR:
-        /* W1C (Write 1 to clear) registers */
-        s->regs[reg] &= ~data;
+        /* W1C (Write 1 to clear) registers are offset by one address from
+         * the data register */
+        s->regs[reg - 1] &= ~data;
         return;
 
     case AST2600_RNG_DATA:
-- 
2.24.0


