From: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
For some SoCs, boot firmware is using the same IPCC instance used
by Linux and it has kept CLEAR_ON_RECV_RD set which basically means
interrupt pending registers are cleared when RECV_ID is read and the
register automatically updates to the next pending interrupt/client
status based on priority.
Clear the CLEAR_ON_RECV_RD if it is set from the boot firmware.
Signed-off-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxxxx>
---
drivers/mailbox/qcom-ipcc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
index 14c7907c6632..0b17a38ea6bf 100644
--- a/drivers/mailbox/qcom-ipcc.c
+++ b/drivers/mailbox/qcom-ipcc.c
@@ -14,6 +14,7 @@
#include <dt-bindings/mailbox/qcom-ipcc.h>
/* IPCC Register offsets */
+#define IPCC_REG_CONFIG 0x08
#define IPCC_REG_SEND_ID 0x0c
#define IPCC_REG_RECV_ID 0x10
#define IPCC_REG_RECV_SIGNAL_ENABLE 0x14
@@ -21,6 +22,7 @@
#define IPCC_REG_RECV_SIGNAL_CLEAR 0x1c
#define IPCC_REG_CLIENT_CLEAR 0x38
+#define IPCC_CLEAR_ON_RECV_RD BIT(0)
#define IPCC_SIGNAL_ID_MASK GENMASK(15, 0)
#define IPCC_CLIENT_ID_MASK GENMASK(31, 16)
@@ -274,6 +276,7 @@ static int qcom_ipcc_pm_resume(struct device *dev)
static int qcom_ipcc_probe(struct platform_device *pdev)
{
struct qcom_ipcc *ipcc;
+ u32 config_value;
static int id;
char *name;
int ret;
@@ -288,6 +291,19 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
if (IS_ERR(ipcc->base))
return PTR_ERR(ipcc->base);
+ /*
+ * It is possible that boot firmware is using the same IPCC instance
+ * as of the HLOS and it has kept CLEAR_ON_RECV_RD set which basically
+ * means Interrupt pending registers are cleared when RECV_ID is read.
+ * The register automatically updates to the next pending interrupt/client
+ * status based on priority.
+ */
+ config_value = readl(ipcc->base + IPCC_REG_CONFIG);
+ if (config_value & IPCC_CLEAR_ON_RECV_RD) {
+ config_value &= ~(IPCC_CLEAR_ON_RECV_RD);
+ writel(config_value, ipcc->base + IPCC_REG_CONFIG);
+ }
+
ipcc->irq = platform_get_irq(pdev, 0);
if (ipcc->irq < 0)
return ipcc->irq;
--
2.34.1
