[PATCH] mailbox: zynqmp-ipi: Make polling period configurable from kconfig

[Ben Levinsky <ben.levinsky@amd.com>]

The polling period for ZynqMP IPI Mailbox is currently hard-coded to
five milliseconds. To avoid patching this when modifying the value, the
value is now set with default that can be overwritten from kconfig
prompt.

Signed-off-by: Ben Levinsky <ben.levinsky@amd.com>
---
 drivers/mailbox/Kconfig              | 12 ++++++++++++
 drivers/mailbox/zynqmp-ipi-mailbox.c |  9 ++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 3b8842c4a340..c87a92400616 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -259,6 +259,18 @@ config ZYNQMP_IPI_MBOX
 	  message to the IPI buffer and will access the IPI control
 	  registers to kick the other processor or enquire status.
 
+config ZYNQMP_IPI_MBOX_POLL_PERIOD
+	int
+	prompt "ZynqMP IPI Mailbox driver polling period"
+	default 5
+	depends on ZYNQMP_IPI_MBOX
+	help
+	  By default the Xilinx-AMD IPI mailbox driver has a polling period
+	  of five milliseconds. If this option is set then the provided value
+	  will be used.
+
+	  Leave as default if not sure.
+
 config SUN6I_MSGBOX
 	tristate "Allwinner sun6i/sun8i/sun9i/sun50i Message Box"
 	depends on ARCH_SUNXI || COMPILE_TEST
diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
index 4acf5612487c..df540e2b9dbe 100644
--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -64,6 +64,13 @@
 
 #define MAX_SGI 16
 
+/* Polling period in milliseconds. */
+#ifndef CONFIG_ZYNQMP_IPI_MBOX_POLL_PERIOD
+#define ZYNQMP_IPI_MBOX_POLL_PERIOD (5U)
+#else
+#define ZYNQMP_IPI_MBOX_POLL_PERIOD CONFIG_ZYNQMP_IPI_MBOX_POLL_PERIOD
+#endif
+
 /**
  * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
  * @is_opened: indicate if the IPI channel is opened
@@ -537,7 +544,7 @@ static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
 	mbox->num_chans = 2;
 	mbox->txdone_irq = false;
 	mbox->txdone_poll = true;
-	mbox->txpoll_period = 5;
+	mbox->txpoll_period = ZYNQMP_IPI_MBOX_POLL_PERIOD;
 	mbox->of_xlate = zynqmp_ipi_of_xlate;
 	chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL);
 	if (!chans)
-- 
2.25.1