On Tue, Aug 3, 2021 at 1:19 AM Atish Patra [off-list ref] wrote:

On Sat, Jul 24, 2021 at 5:25 AM Anup Patel [off-list ref] wrote:

quoted

We can have ACLINT MTIMER devices which only support 32-bit MMIO
accesses on RV64 system so this patch adds a boolean DT property
"mtimer,no-64bit-mmio" to detect this from MTIMER DT node.

Where is this property documented ? I couldn't find it in your v3
aclint patch [1].
Did I miss something?

I have updated DT bindings in linux v3 series. Please check again.

I also think "mtimer,32bit-mmio" may be a better choice than
"mtimer,no-64bit-mmio"

[1]https://github.com/avpatel/linux/commits/riscv_aclint_v3

Actually, "mtimer,no-64bit-mmio" is more appropriate because
all registers of MTIMER are 64-bits wide so by default RV64
systems should support 64-bit MMIO for MTIMER. In fact, most
existing RV64 systems do support 64-bit MMIO for MTIMER.

Regards,
Anup

quoted

Signed-off-by: Anup Patel <redacted>
---
 lib/utils/timer/fdt_timer_mtimer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/utils/timer/fdt_timer_mtimer.c b/lib/utils/timer/fdt_timer_mtimer.c
index b08ed38..15a36ed 100644
--- a/lib/utils/timer/fdt_timer_mtimer.c
+++ b/lib/utils/timer/fdt_timer_mtimer.c

@@ -58,6 +58,9 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
                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;
        }

        rc = aclint_mtimer_cold_init(mt, mtmaster);
--

2.25.1


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Regards,
Atish