[PATCH net-next 2/3] net: systemport: fetch and use clock resources

[Florian Fainelli]

We disable clocks shortly after probing the device to save as much power as
possible in case the interface is never used. When bcm_sysport_open() is
invoked, clocks are enabled, and disabled in bcm_sysport_stop().

A similar scheme is applied to the suspend/resume functions.

Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
 drivers/net/ethernet/broadcom/bcmsysport.c | 30 +++++++++++++++++++++-
 drivers/net/ethernet/broadcom/bcmsysport.h |  1 +
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c 
b/drivers/net/ethernet/broadcom/bcmsysport.c
index dfed9ade6950..91eadba5540c 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -20,6 +20,7 @@
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
 #include <net/dsa.h>
+#include <linux/clk.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
 
@@ -186,6 +187,11 @@ static int bcm_sysport_set_features(struct net_device *dev,
                                    netdev_features_t features)
 {
        struct bcm_sysport_priv *priv = netdev_priv(dev);
+       int ret;
+
+       ret = clk_prepare_enable(priv->clk);
+       if (ret)
+               return ret;
 
        /* Read CRC forward */
        if (!priv->is_lite)
@@ -197,6 +203,8 @@ static int bcm_sysport_set_features(struct net_device *dev,
        bcm_sysport_set_rx_csum(dev, features);
        bcm_sysport_set_tx_csum(dev, features);
 
+       clk_disable_unprepare(priv->clk);
+
        return 0;
 }
 
@@ -1940,6 +1948,8 @@ static int bcm_sysport_open(struct net_device *dev)
        unsigned int i;
        int ret;
 
+       clk_prepare_enable(priv->clk);
+
        /* Reset UniMAC */
        umac_reset(priv);
 
@@ -1970,7 +1980,8 @@ static int bcm_sysport_open(struct net_device *dev)
                                0, priv->phy_interface);
        if (!phydev) {
                netdev_err(dev, "could not attach to PHY\n");
-               return -ENODEV;
+               ret = -ENODEV;
+               goto out_clk_disable;
        }
 
        /* Reset house keeping link status */
@@ -2048,6 +2059,8 @@ static int bcm_sysport_open(struct net_device *dev)
        free_irq(priv->irq0, dev);
 out_phy_disconnect:
        phy_disconnect(phydev);
+out_clk_disable:
+       clk_disable_unprepare(priv->clk);
        return ret;
 }
 
@@ -2106,6 +2119,8 @@ static int bcm_sysport_stop(struct net_device *dev)
        /* Disconnect from PHY */
        phy_disconnect(dev->phydev);
 
+       clk_disable_unprepare(priv->clk);
+
        return 0;
 }
 
@@ -2487,6 +2502,10 @@ static int bcm_sysport_probe(struct platform_device 
*pdev)
        /* Initialize private members */
        priv = netdev_priv(dev);
 
+       priv->clk = devm_clk_get_optional(&pdev->dev, "sw_sysport");
+       if (IS_ERR(priv->clk))
+               return PTR_ERR(priv->clk);
+
        /* Allocate number of TX rings */
        priv->tx_rings = devm_kcalloc(&pdev->dev, txq,
                                      sizeof(struct bcm_sysport_tx_ring),
@@ -2588,6 +2607,8 @@ static int bcm_sysport_probe(struct platform_device *pdev)
                goto err_deregister_notifier;
        }
 
+       clk_prepare_enable(priv->clk);
+
        priv->rev = topctrl_readl(priv, REV_CNTL) & REV_MASK;
        dev_info(&pdev->dev,
                 "Broadcom SYSTEMPORT%s " REV_FMT
@@ -2596,6 +2617,8 @@ static int bcm_sysport_probe(struct platform_device *pdev)
                 (priv->rev >> 8) & 0xff, priv->rev & 0xff,
                 priv->irq0, priv->irq1, txq, rxq);
 
+       clk_disable_unprepare(priv->clk);
+
        return 0;
 
 err_deregister_notifier:
@@ -2752,6 +2775,8 @@ static int __maybe_unused bcm_sysport_suspend(struct 
device *d)
        if (device_may_wakeup(d) && priv->wolopts)
                ret = bcm_sysport_suspend_to_wol(priv);
 
+       clk_disable_unprepare(priv->clk);
+
        return ret;
 }
 
@@ -2765,6 +2790,8 @@ static int __maybe_unused bcm_sysport_resume(struct 
device *d)
        if (!netif_running(dev))
                return 0;
 
+       clk_prepare_enable(priv->clk);
+
        umac_reset(priv);
 
        /* Disable the UniMAC RX/TX */
@@ -2844,6 +2871,7 @@ static int __maybe_unused bcm_sysport_resume(struct 
device *d)
 out_free_tx_rings:
        for (i = 0; i < dev->num_tx_queues; i++)
                bcm_sysport_fini_tx_ring(priv, i);
+       clk_disable_unprepare(priv->clk);
        return ret;
 }
 
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.h 
b/drivers/net/ethernet/broadcom/bcmsysport.h
index 6d80735fbc7f..51800053e88c 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.h
+++ b/drivers/net/ethernet/broadcom/bcmsysport.h
@@ -770,6 +770,7 @@ struct bcm_sysport_priv {
        u32                     wolopts;
        u8                      sopass[SOPASS_MAX];
        unsigned int            wol_irq_disabled:1;
+       struct clk              *clk;
 
        /* MIB related fields */
        struct bcm_sysport_mib  mib;
-- 
2.25.1