[RFC PATCH 2/2] lib: utils/timer: Add a separate compatible for the D1 CLINT

[Samuel Holland]

The CLINT in the Allwinner D1 SoC apparently does not support 64-bit
MMIO access. A property was added to support this quirk (and that
property was copied to the ACLINT MTIMER code). However, since this
difference in behavior makes the D1 CLINT incompatible with the SiFive
CLINT's programming interface, a better solution is to use a separate
compatible string.

Signed-off-by: Samuel Holland <samuel at sholland.org>
---
 docs/platform/thead-c9xx.md        |  4 +--
 lib/utils/ipi/fdt_ipi_mswi.c       |  1 +
 lib/utils/timer/fdt_timer_mtimer.c | 39 +++++++++++++++++++-----------
 3 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/docs/platform/thead-c9xx.md b/docs/platform/thead-c9xx.md
index 3490ed5..ced784d 100644
--- a/docs/platform/thead-c9xx.md
+++ b/docs/platform/thead-c9xx.md
@@ -52,12 +52,11 @@ DTS Example1: (Single core, eg: Allwinner D1 - c906)
 		ranges;
 
 		clint0: clint at 14000000 {
-			compatible = "riscv,clint0";
+			compatible = "allwinner,sun20i-d1-clint";
 			interrupts-extended = <
 				&cpu0_intc  3 &cpu0_intc  7
 				>;
 			reg = <0x0 0x14000000 0x0 0x04000000>;
-			clint,has-no-64bit-mmio;
 		};
 
 		intc: interrupt-controller at 10000000 {
@@ -163,7 +162,6 @@ DTS Example2: (Multi cores with soc reset-regs)
 				&cpu4_intc  3 &cpu4_intc  7
 				>;
 			reg = <0xff 0xdc000000 0x0 0x04000000>;
-			clint,has-no-64bit-mmio;
 		};
 
 		intc: interrupt-controller at ffd8000000 {
diff --git a/lib/utils/ipi/fdt_ipi_mswi.c b/lib/utils/ipi/fdt_ipi_mswi.c
index 0176941..af69e16 100644
--- a/lib/utils/ipi/fdt_ipi_mswi.c
+++ b/lib/utils/ipi/fdt_ipi_mswi.c
@@ -54,6 +54,7 @@ static int ipi_mswi_cold_init(void *fdt, int nodeoff,
 static const unsigned long clint_offset = CLINT_MSWI_OFFSET;
 
 static const struct fdt_match ipi_mswi_match[] = {
+	{ .compatible = "allwinner,sun20i-d1-clint", .data = &clint_offset },
 	{ .compatible = "riscv,clint0", .data = &clint_offset },
 	{ .compatible = "sifive,clint0", .data = &clint_offset },
 	{ .compatible = "riscv,aclint-mswi" },
diff --git a/lib/utils/timer/fdt_timer_mtimer.c b/lib/utils/timer/fdt_timer_mtimer.c
index 1ad8508..e140567 100644
--- a/lib/utils/timer/fdt_timer_mtimer.c
+++ b/lib/utils/timer/fdt_timer_mtimer.c
@@ -15,6 +15,11 @@
 
 #define MTIMER_MAX_NR			16
 
+struct timer_mtimer_quirks {
+	unsigned int	mtime_offset;
+	bool		has_64bit_mmio;
+};
+
 static unsigned long mtimer_count = 0;
 static struct aclint_mtimer_data mtimer[MTIMER_MAX_NR];
 static struct aclint_mtimer_data *mt_reference = NULL;
@@ -23,7 +28,7 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
 				  const struct fdt_match *match)
 {
 	int i, rc;
-	unsigned long offset, addr[2], size[2];
+	unsigned long addr[2], size[2];
 	struct aclint_mtimer_data *mt;
 
 	if (MTIMER_MAX_NR <= mtimer_count)
@@ -43,28 +48,25 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
 		return rc;
 
 	if (match->data) { /* SiFive CLINT */
+		const struct timer_mtimer_quirks *quirks = match->data;
+
 		/* Set CLINT addresses */
 		mt->mtimecmp_addr = addr[0] + ACLINT_DEFAULT_MTIMECMP_OFFSET;
 		mt->mtimecmp_size = ACLINT_DEFAULT_MTIMECMP_SIZE;
 		mt->mtime_addr = addr[0] + ACLINT_DEFAULT_MTIME_OFFSET;
 		mt->mtime_size = size[0] - mt->mtimecmp_size;
 		/* Adjust MTIMER address and size for CLINT device */
-		offset = *((unsigned long *)match->data);
-		mt->mtime_addr += offset;
-		mt->mtimecmp_addr += offset;
-		mt->mtime_size -= offset;
-		/* Parse additional CLINT properties */
-		if (fdt_getprop(fdt, nodeoff, "clint,has-no-64bit-mmio", &rc))
-			mt->has_64bit_mmio = false;
+		mt->mtime_addr += quirks->mtime_offset;
+		mt->mtimecmp_addr += quirks->mtime_offset;
+		mt->mtime_size -= quirks->mtime_offset;
+		/* Apply additional CLINT quirks */
+		mt->has_64bit_mmio = quirks->has_64bit_mmio;
 	} else { /* RISC-V ACLINT MTIMER */
 		/* Set ACLINT MTIMER addresses */
 		mt->mtime_addr = addr[0];
 		mt->mtime_size = size[0];
 		mt->mtimecmp_addr = addr[1];
 		mt->mtimecmp_size = size[1];
-		/* Parse additional ACLINT MTIMER properties */
-		if (fdt_getprop(fdt, nodeoff, "mtimer,no-64bit-mmio", &rc))
-			mt->has_64bit_mmio = false;
 	}
 
 	/* Check if MTIMER device has shared MTIME address */
@@ -107,11 +109,20 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
 	return 0;
 }
 
-static unsigned long clint_offset = CLINT_MTIMER_OFFSET;
+static const struct timer_mtimer_quirks d1_clint_quirks = {
+	.mtime_offset	= CLINT_MTIMER_OFFSET,
+	.has_64bit_mmio	= false,
+};
+
+static const struct timer_mtimer_quirks sifive_clint_quirks = {
+	.mtime_offset	= CLINT_MTIMER_OFFSET,
+	.has_64bit_mmio	= true,
+};
 
 static const struct fdt_match timer_mtimer_match[] = {
-	{ .compatible = "riscv,clint0", .data = &clint_offset },
-	{ .compatible = "sifive,clint0", .data = &clint_offset },
+	{ .compatible = "allwinner,sun20i-d1-clint", .data = &d1_clint_quirks },
+	{ .compatible = "riscv,clint0", .data = &sifive_clint_quirks },
+	{ .compatible = "sifive,clint0", .data = &sifive_clint_quirks },
 	{ .compatible = "riscv,aclint-mtimer" },
 	{ },
 };
-- 
2.32.0