[PATCH v3 4/5] wifi: brcmfmac: Add optional lpo clock enable support

[Jacobe Zang]

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

Co-developed-by: Ondrej Jirman <megi at xff.cz>
Signed-off-by: Ondrej Jirman <megi at xff.cz>
Signed-off-by: Jacobe Zang <jacobe.zang at wesion.com>
---
 .../net/wireless/broadcom/brcm80211/brcmfmac/pcie.c    | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
index 06698a714b523..e84f562fc91b8 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2014 Broadcom Corporation
  */
 
+#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/firmware.h>
@@ -2411,6 +2412,7 @@ brcmf_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	struct brcmf_pciedev *pcie_bus_dev;
 	struct brcmf_core *core;
 	struct brcmf_bus *bus;
+	struct clk *clk;
 
 	if (!id) {
 		id = pci_match_id(brcmf_pcie_devid_table, pdev);
@@ -2422,6 +2424,14 @@ brcmf_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	brcmf_dbg(PCIE, "Enter %x:%x\n", pdev->vendor, pdev->device);
 
+	clk = devm_clk_get_optional_enabled(&pdev->dev, "lpo");
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+	if (clk) {
+		brcmf_dbg(PCIE, "enabling 32kHz clock\n", pdev->vendor, pdev->device);
+		clk_set_rate(clk, 32768);
+	}
+
 	ret = -ENOMEM;
 	devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
 	if (devinfo == NULL)
-- 
2.34.1