* Re: [PATCH 2/2] arc_emac: add clock handling
2014-04-23 12:24 ` [PATCH 2/2] arc_emac: add clock handling Heiko Stübner
@ 2014-04-23 21:39 ` Max Schwarz
0 siblings, 0 replies; 2+ messages in thread
From: Max Schwarz @ 2014-04-23 21:39 UTC (permalink / raw)
To: Heiko Stübner
Cc: David S. Miller, Alexey Brodkin, netdev, devicetree, Rob Herring,
Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
On Wednesday 23 April 2014 at 14:24:55, Heiko Stübner wrote:
> This adds ability for the arc_emac to really handle its supplying clock.
> To get the needed clock-frequency either a real clock or the previous
> clock-frequency property must be provided.
>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
> Documentation/devicetree/bindings/net/arc_emac.txt | 12 +++++-
> drivers/net/ethernet/arc/emac.h | 2 +
> drivers/net/ethernet/arc/emac_main.c | 46
> ++++++++++++++++------ 3 files changed, 47 insertions(+), 13 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/arc_emac.txt
> b/Documentation/devicetree/bindings/net/arc_emac.txt index 7fbb027..a1d71eb
> 100644
> --- a/Documentation/devicetree/bindings/net/arc_emac.txt
> +++ b/Documentation/devicetree/bindings/net/arc_emac.txt
> @@ -4,11 +4,15 @@ Required properties:
> - compatible: Should be "snps,arc-emac"
> - reg: Address and length of the register set for the device
> - interrupts: Should contain the EMAC interrupts
> -- clock-frequency: CPU frequency. It is needed to calculate and set polling
> -period of EMAC.
> - max-speed: see ethernet.txt file in the same directory.
> - phy: see ethernet.txt file in the same directory.
>
> +Clock handling:
> +The clock frequency is needed to calculate and set polling period of EMAC.
> +It must be provided by one of:
> +- clock-frequency: CPU frequency.
> +- clocks: reference to the clock supplying the EMAC.
> +
> Child nodes of the driver are the individual PHY devices connected to the
> MDIO bus. They must have a "reg" property given the PHY address on the MDIO
> bus.
>
> @@ -19,7 +23,11 @@ Examples:
> reg = <0xc0fc2000 0x3c>;
> interrupts = <6>;
> mac-address = [ 00 11 22 33 44 55 ];
> +
> clock-frequency = <80000000>;
> + /* or */
> + clocks = <&emac_clock>;
> +
> max-speed = <100>;
> phy = <&phy0>;
>
> diff --git a/drivers/net/ethernet/arc/emac.h
> b/drivers/net/ethernet/arc/emac.h index 928fac6..53f85bf 100644
> --- a/drivers/net/ethernet/arc/emac.h
> +++ b/drivers/net/ethernet/arc/emac.h
> @@ -11,6 +11,7 @@
> #include <linux/dma-mapping.h>
> #include <linux/netdevice.h>
> #include <linux/phy.h>
> +#include <linux/clk.h>
>
> /* STATUS and ENABLE Register bit masks */
> #define TXINT_MASK (1<<0) /* Transmit interrupt */
> @@ -131,6 +132,7 @@ struct arc_emac_priv {
> struct mii_bus *bus;
>
> void __iomem *regs;
> + struct clk *clk;
>
> struct napi_struct napi;
> struct net_device_stats stats;
> diff --git a/drivers/net/ethernet/arc/emac_main.c
> b/drivers/net/ethernet/arc/emac_main.c index 0cba97a..68f8ad5 100644
> --- a/drivers/net/ethernet/arc/emac_main.c
> +++ b/drivers/net/ethernet/arc/emac_main.c
> @@ -649,13 +649,6 @@ static int arc_emac_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> - /* Get CPU clock frequency from device tree */
> - if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> - &clock_frequency)) {
> - dev_err(&pdev->dev, "failed to retrieve <clock-frequency> from device
> tree\n"); - return -EINVAL;
> - }
> -
> /* Get IRQ from device tree */
> irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
> if (!irq) {
> @@ -687,13 +680,32 @@ static int arc_emac_probe(struct platform_device
> *pdev) }
> dev_dbg(&pdev->dev, "Registers base address is 0x%p\n", priv->regs);
>
> + priv->clk = of_clk_get(pdev->dev.of_node, 0);
> + if (IS_ERR(priv->clk)) {
> + /* Get CPU clock frequency from device tree */
> + if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> + &clock_frequency)) {
> + dev_err(&pdev->dev, "failed to retrieve <clock-frequency> from device
> tree\n"); + err = -EINVAL;
> + goto out_netdev;
> + }
> + } else {
> + err = clk_prepare_enable(priv->clk);
> + if (err) {
> + dev_err(&pdev->dev, "failed to enable clock\n");
> + goto out_clkget;
> + }
> +
> + clock_frequency = clk_get_rate(priv->clk);
> + }
> +
> id = arc_reg_get(priv, R_ID);
>
> /* Check for EMAC revision 5 or 7, magic number */
> if (!(id == 0x0005fd02 || id == 0x0007fd02)) {
> dev_err(&pdev->dev, "ARC EMAC not detected, id=0x%x\n", id);
> err = -ENODEV;
> - goto out_netdev;
> + goto out_clken;
> }
> dev_info(&pdev->dev, "ARC EMAC detected with id: 0x%x\n", id);
>
> @@ -708,7 +720,7 @@ static int arc_emac_probe(struct platform_device *pdev)
> ndev->name, ndev);
> if (err) {
> dev_err(&pdev->dev, "could not allocate IRQ\n");
> - goto out_netdev;
> + goto out_clken;
> }
>
> /* Get MAC address from device tree */
> @@ -729,7 +741,7 @@ static int arc_emac_probe(struct platform_device *pdev)
> if (!priv->rxbd) {
> dev_err(&pdev->dev, "failed to allocate data buffers\n");
> err = -ENOMEM;
> - goto out_netdev;
> + goto out_clken;
> }
>
> priv->txbd = priv->rxbd + RX_BD_NUM;
> @@ -741,7 +753,7 @@ static int arc_emac_probe(struct platform_device *pdev)
> err = arc_mdio_probe(pdev, priv);
> if (err) {
> dev_err(&pdev->dev, "failed to probe MII bus\n");
> - goto out_netdev;
> + goto out_clken;
> }
>
> priv->phy_dev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,
> @@ -772,6 +784,12 @@ out_netif_api:
> priv->phy_dev = NULL;
> out_mdio:
> arc_mdio_remove(priv);
> +out_clken:
> + if (IS_ERR(priv->clk))
> + clk_disable_unprepare(priv->clk);
Should be if (!IS_ERR(priv->clk)).
> +out_clkget:
> + if (IS_ERR(priv->clk))
> + clk_put(priv->clk);
The same.
> out_netdev:
> free_netdev(ndev);
> return err;
> @@ -787,6 +805,12 @@ static int arc_emac_remove(struct platform_device
> *pdev) arc_mdio_remove(priv);
> unregister_netdev(ndev);
> netif_napi_del(&priv->napi);
> +
> + if (!IS_ERR(priv->clk)) {
> + clk_disable_unprepare(priv->clk);
> + clk_put(priv->clk);
> + }
> +
> free_netdev(ndev);
>
> return 0;
Apart from that, the clock stuff has been
Tested-by: Max Schwarz <max.schwarz@online.de>
(on the same hardware, radxa rock)
Cheers,
Max
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