[PATCH] staging: wilc1000: look for rtc_clk clock in spi mode

[<Adham.Abozaeid@microchip.com>]

From: Adham Abozaeid <adham.abozaeid@microchip.com>

If rtc_clk is provided from DT, use it and enable it.
This is optional.
The signal may be hardcoded and no need to be requested,
but if DT provides it, use it.

Signed-off-by: Adham Abozaeid <adham.abozaeid@microchip.com>
---
 drivers/staging/wilc1000/wilc_spi.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/staging/wilc1000/wilc_spi.c b/drivers/staging/wilc1000/wilc_spi.c
index 3c1ae9e9f9aa..166455a969bf 100644
--- a/drivers/staging/wilc1000/wilc_spi.c
+++ b/drivers/staging/wilc1000/wilc_spi.c
@@ -4,6 +4,7 @@
  * All rights reserved.
  */
 
+#include <linux/clk.h>
 #include <linux/spi/spi.h>
 
 #include "wilc_wfi_netdevice.h"
@@ -132,6 +133,12 @@ static int wilc_bus_probe(struct spi_device *spi)
 	wilc->bus_data = spi_priv;
 	wilc->gpio_irq = gpio;
 
+	wilc->rtc_clk = devm_clk_get(&spi->dev, "rtc_clk");
+	if (PTR_ERR_OR_ZERO(wilc->rtc_clk) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	else if (!IS_ERR(wilc->rtc_clk))
+		clk_prepare_enable(wilc->rtc_clk);
+
 	return 0;
 }
 
@@ -142,6 +149,10 @@ static int wilc_bus_remove(struct spi_device *spi)
 	/* free the GPIO in module remove */
 	if (wilc->gpio_irq)
 		gpiod_put(wilc->gpio_irq);
+
+	if (!IS_ERR(wilc->rtc_clk))
+		clk_disable_unprepare(wilc->rtc_clk);
+
 	wilc_netdev_cleanup(wilc);
 	return 0;
 }
-- 
2.17.1