[PATCH 2/3] riscv: clint: Update the sifive clint ipi driver to support aclint

[Bin Meng]

This RISC-V ACLINT specification [1] defines a set of memory mapped
devices which provide inter-processor interrupts (IPI) and timer
functionalities for each HART on a multi-HART RISC-V platform.

The RISC-V ACLINT specification is defined to be backward compatible
with the SiFive CLINT specification, however the device tree binding
is a new one. This change updates the sifive clint ipi driver to
support ACLINT mswi device, by checking the per-driver data field of
the ACLINT mtimer driver to determine whether a syscon based approach
needs to be taken to get the base address of the ACLINT mswi device.

[1] https://github.com/riscv/riscv-aclint/blob/main/riscv-aclint.adoc

Signed-off-by: Bin Meng <bmeng at tinylab.org>
---

 arch/riscv/Kconfig            |  4 ++++
 arch/riscv/lib/sifive_clint.c | 21 ++++++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index f6ed05906a..9fcdd8c451 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -188,6 +188,8 @@ config DMA_ADDR_T_64BIT
 config SIFIVE_CLINT
 	bool
 	depends on RISCV_MMODE
+	select REGMAP
+	select SYSCON
 	help
 	  The SiFive CLINT block holds memory-mapped control and status registers
 	  associated with software and timer interrupts.
@@ -195,6 +197,8 @@ config SIFIVE_CLINT
 config SPL_SIFIVE_CLINT
 	bool
 	depends on SPL_RISCV_MMODE
+	select SPL_REGMAP
+	select SPL_SYSCON
 	help
 	  The SiFive CLINT block holds memory-mapped control and status registers
 	  associated with software and timer interrupts.
diff --git a/arch/riscv/lib/sifive_clint.c b/arch/riscv/lib/sifive_clint.c
index ab22395c55..f242168381 100644
--- a/arch/riscv/lib/sifive_clint.c
+++ b/arch/riscv/lib/sifive_clint.c
@@ -10,9 +10,12 @@
 
 #include <common.h>
 #include <dm.h>
+#include <regmap.h>
+#include <syscon.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
 #include <asm/smp.h>
+#include <asm/syscon.h>
 #include <linux/err.h>
 
 /* MSIP registers */
@@ -30,7 +33,11 @@ int riscv_init_ipi(void)
 	if (ret)
 		return ret;
 
-	gd->arch.clint = dev_read_addr_ptr(dev);
+	if (dev_get_driver_data(dev) != 0)
+		gd->arch.clint = dev_read_addr_ptr(dev);
+	else
+		gd->arch.clint = syscon_get_first_range(RISCV_SYSCON_CLINT);
+
 	if (!gd->arch.clint)
 		return -EINVAL;
 
@@ -57,3 +64,15 @@ int riscv_get_ipi(int hart, int *pending)
 
 	return 0;
 }
+
+static const struct udevice_id riscv_aclint_swi_ids[] = {
+	{ .compatible = "riscv,aclint-mswi", .data = RISCV_SYSCON_CLINT },
+	{ }
+};
+
+U_BOOT_DRIVER(riscv_aclint_swi) = {
+	.name		= "riscv_aclint_swi",
+	.id		= UCLASS_SYSCON,
+	.of_match	= riscv_aclint_swi_ids,
+	.flags		= DM_FLAG_PRE_RELOC,
+};
-- 
2.25.1