cnss: Make bus bandwidth request optional

If device tree entry doesn't exist for bus bandwidth then
initialization of cnss driver fails. If device tree entry doesn't
exist then cnss driver needs to handle this case gracefully.
Modified driver to ignore the bus bandwidth request if device
tree entry doesn't exist.

Change-Id: Ib0e0d04d34d72bea633c74f436eeec625b986347
Signed-off-by: Prashanth Bhatta <bhattap@codeaurora.org>

1 files changed, 25 insertions, 12 deletions

diff --git a/drivers/net/wireless/cnss/cnss.c b/drivers/net/wireless/cnss/cnss.c
index 715abf2c66dc..6c72d644fc38 100644
--- a/drivers/net/wireless/cnss/cnss.c
+++ b/drivers/net/wireless/cnss/cnss.c
@@ -546,7 +546,8 @@ void cnss_wlan_unregister_driver(struct cnss_wlan_driver *driver)
 		return;
 	}
 
-	msm_bus_scale_client_update_request(penv->bus_client, 0);
+	if (penv->bus_client)
+		msm_bus_scale_client_update_request(penv->bus_client, 0);
 
 	if (!pdev) {
 		pr_err("%d: invalid pdev\n", __LINE__);
@@ -969,22 +970,25 @@ static int cnss_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_pci_reg;
 
+	penv->bus_scale_table = 0;
 	penv->bus_scale_table = msm_bus_cl_get_pdata(pdev);
-	if (!penv->bus_scale_table)
-		goto err_bus_scale;
 
-	penv->bus_client = msm_bus_scale_register_client
-	    (penv->bus_scale_table);
-	if (!penv->bus_client)
-		goto err_bus_reg;
+	if (penv->bus_scale_table)  {
+		penv->bus_client =
+			msm_bus_scale_register_client(penv->bus_scale_table);
+
+		if (!penv->bus_client) {
+			pr_err("Failed to register with bus_scale client\n");
+			goto err_bus_reg;
+		}
+	}
 
 	pr_info("cnss: Platform driver probed successfully.\n");
 	return ret;
 
 err_bus_reg:
-	msm_bus_cl_clear_pdata(penv->bus_scale_table);
-
-err_bus_scale:
+	if (penv->bus_scale_table)
+		msm_bus_cl_clear_pdata(penv->bus_scale_table);
 	pci_unregister_driver(&cnss_wlan_pci_driver);
 
 err_pci_reg:
@@ -1010,6 +1014,12 @@ static int cnss_remove(struct platform_device *pdev)
 	struct cnss_wlan_vreg_info *vreg_info = &penv->vreg_info;
 	struct cnss_wlan_gpio_info *gpio_info = &penv->gpio_info;
 
+	if (penv->bus_client)
+		msm_bus_scale_unregister_client(penv->bus_client);
+
+	if (penv->bus_scale_table)
+		msm_bus_cl_clear_pdata(penv->bus_scale_table);
+
 	cnss_wlan_gpio_set(gpio_info, WLAN_EN_LOW);
 	if (cnss_wlan_vreg_set(vreg_info, VREG_OFF))
 		pr_err("Failed to turn OFF wlan vreg\n");
@@ -1065,16 +1075,19 @@ int cnss_request_bus_bandwidth(int bandwidth)
 {
 	int ret = 0;
 
-	if (!penv || !penv->bus_client)
+	if (!penv)
 		return -ENODEV;
 
+	if (!penv->bus_client)
+		return -ENOSYS;
+
 	switch (bandwidth) {
 	case CNSS_BUS_WIDTH_NONE:
 	case CNSS_BUS_WIDTH_LOW:
 	case CNSS_BUS_WIDTH_MEDIUM:
 	case CNSS_BUS_WIDTH_HIGH:
 		ret = msm_bus_scale_client_update_request(penv->bus_client,
-							  bandwidth);
+				bandwidth);
 		if (ret)
 			pr_err("%s: could not set bus bandwidth %d, ret = %d\n",
 			       __func__, bandwidth, ret);