[PATCH 1/4] i3c: mipi-i3c-hci: Allow only relevant INTR_STATUS bit updates

[Jarkko Nikula]

Since MIPI I3C HCI specification version v0.8 INTR_STATUS bits 9:0 are
reserved. Version v0.5 has bits 9 and 5:0 in use but not handled by the
current driver code and not needed in DMA transfers.

PIO transfers with v0.5 would require changes to both
core.c: i3c_hci_irq_handler() and pio.c: hci_pio_irq_handler() though.

For these reasons don't enable signal updates from INTR_STATUS bits 9:0.

This change is a no-op for specification versions v0.8 and beyond but
gets rid of "unexpected INTR_STATUS" errors if somebody (read me) wants
to run code on old v0.5 IP version.

Signed-off-by: Jarkko Nikula <jarkko.nikula at linux.intel.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index a71226d7ca59..e139d7e4d252 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -699,9 +699,10 @@ static int i3c_hci_init(struct i3c_hci *hci)
 	if (ret)
 		return -ENXIO;
 
-	/* Disable all interrupts and allow all signal updates */
+	/* Disable all interrupts */
 	reg_write(INTR_SIGNAL_ENABLE, 0x0);
-	reg_write(INTR_STATUS_ENABLE, 0xffffffff);
+	/* Allow signal updates relevant to IP versions 0.8 and beyond */
+	reg_write(INTR_STATUS_ENABLE, GENMASK(31, 10));
 
 	/* Make sure our data ordering fits the host's */
 	regval = reg_read(HC_CONTROL);
-- 
2.47.2