net:fec: add enet refrence clock for i.MX 6SX chip

i.MX6sx enet has below clocks for user config:
clk_ipg: ipg_clk_s, ipg_clk_mac0_s, 66Mhz
clk_ahb: enet system clock, it is enet AXI clock for imx6sx.
	 For imx6sx, it alos is the clock source of interrupt coalescing.
	 The clock range: 200Mhz ~ 266Mhz.
clk_ref: refrence clock for tx and rx. For imx6sx enet RGMII mode,
	 the refrence clock is 125Mhz coming from internal PLL or external.
	 In i.MX6sx-arm2 board, the clock is from internal PLL.
	 clk_ref is optional, depends on board.
clk_enet_out: The clock can be output from internal PLL. It can supply 50Mhz
	 clock for phy. clk_enet_out is optional, depends on chip and board.
clk_ptp: 1588 ts clock. It is optional, depends on chip.

The patch add clk_ref to distiguish the different clocks.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index ee41d98..635772b 100644 (file)
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -272,6 +272,7 @@ struct fec_enet_private {
 
        struct clk *clk_ipg;
        struct clk *clk_ahb;
+       struct clk *clk_ref;
        struct clk *clk_enet_out;
        struct clk *clk_ptp;
 

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 89355a7..c21ecff 100644 (file)
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1621,6 +1621,11 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
                        }
                        mutex_unlock(&fep->ptp_clk_mutex);
                }
+               if (fep->clk_ref) {
+                       ret = clk_prepare_enable(fep->clk_ref);
+                       if (ret)
+                               goto failed_clk_ref;
+               }
        } else {
                clk_disable_unprepare(fep->clk_ahb);
                clk_disable_unprepare(fep->clk_ipg);
@@ -1632,9 +1637,15 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
                        fep->ptp_clk_on = false;
                        mutex_unlock(&fep->ptp_clk_mutex);
                }
+               if (fep->clk_ref)
+                       clk_disable_unprepare(fep->clk_ref);
        }
 
        return 0;
+
+failed_clk_ref:
+       if (fep->clk_ref)
+               clk_disable_unprepare(fep->clk_ref);
 failed_clk_ptp:
        if (fep->clk_enet_out)
                clk_disable_unprepare(fep->clk_enet_out);
@@ -2637,6 +2648,12 @@ fec_probe(struct platform_device *pdev)
 
        fep->ptp_clk_on = false;
        mutex_init(&fep->ptp_clk_mutex);
+
+       /* clk_ref is optional, depends on board */
+       fep->clk_ref = devm_clk_get(&pdev->dev, "enet_clk_ref");
+       if (IS_ERR(fep->clk_ref))
+               fep->clk_ref = NULL;
+
        fep->clk_ptp = devm_clk_get(&pdev->dev, "ptp");
        fep->bufdesc_ex =
                pdev->id_entry->driver_data & FEC_QUIRK_HAS_BUFDESC_EX;