[PATCH v8 4/6] crypto: ccp: Use lower 8 bytes to communicate with doorbell command register

From: Mario Limonciello
Date: Mon Apr 03 2023 - 14:33:22 EST


Unlike other command registers used by the PSP, only the lower 8 bytes are
used for communication for both command and status of the command.

Suggested-by: Mark Hasemeyer <markhas@xxxxxxxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Reviewed-by: Mark Hasemeyer <markhas@xxxxxxxxxxxx>
Tested-by: Mark Hasemeyer <markhas@xxxxxxxxxxxx>
---
drivers/crypto/ccp/platform-access.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/ccp/platform-access.c b/drivers/crypto/ccp/platform-access.c
index 48f59ae91692..939c924fc383 100644
--- a/drivers/crypto/ccp/platform-access.c
+++ b/drivers/crypto/ccp/platform-access.c
@@ -19,6 +19,7 @@
#include "platform-access.h"

#define PSP_CMD_TIMEOUT_US (500 * USEC_PER_MSEC)
+#define DOORBELL_CMDRESP_STS GENMASK(7, 0)

/* Recovery field should be equal 0 to start sending commands */
static int check_recovery(u32 __iomem *cmd)
@@ -154,7 +155,7 @@ int psp_ring_platform_doorbell(int msg, u32 *result)
goto unlock;
}

- iowrite32(FIELD_PREP(PSP_DRBL_MSG, msg), cmd);
+ iowrite32(FIELD_PREP(DOORBELL_CMDRESP_STS, msg), cmd);
iowrite32(PSP_DRBL_RING, button);

if (wait_cmd(cmd)) {
@@ -162,7 +163,7 @@ int psp_ring_platform_doorbell(int msg, u32 *result)
goto unlock;
}

- val = FIELD_GET(PSP_CMDRESP_STS, ioread32(cmd));
+ val = FIELD_GET(DOORBELL_CMDRESP_STS, ioread32(cmd));
if (val) {
if (result)
*result = val;
--
2.34.1