WiFi modules often require 32kHz clock to function. Add support to
enable the clock to PCIe driver.

Co-developed-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Jacobe Zang <redacted>
---
  drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c | 8 ++++++++
  1 file changed, 8 insertions(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
index e406e11481a62..6246e3fd7399f 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c

@@ -6,6 +6,7 @@
  #include <linux/of.h>
  #include <linux/of_irq.h>
  #include <linux/of_net.h>
+#include <linux/clk.h>
  
  #include <defs.h>
  #include "debug.h"

@@ -70,6 +71,7 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
  {
  	struct brcmfmac_sdio_pd *sdio = &settings->bus.sdio;
  	struct device_node *root, *np = dev->of_node;
+	struct clk *clk;
  	const char *prop;
  	int irq;
  	int err;

@@ -113,6 +115,12 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
  		of_node_put(root);
  	}
  
+	clk = devm_clk_get_optional_enabled(dev, "lpo");
+	if (!IS_ERR_OR_NULL(clk)) {
+		brcmf_dbg(INFO, "enabling 32kHz clock\n");
+		clk_set_rate(clk, 32768);
+	}
+
  	if (!np || !of_device_is_compatible(np, "brcm,bcm4329-fmac"))
  		return;