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Message-ID: <1373877289.24799.242.camel@smile>
Date: Mon, 15 Jul 2013 11:34:49 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Darren Hart <dvhart@...ux.intel.com>
Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
"David S. Miller" <davem@...emloft.net>,
"H. Peter Anvin" <hpa@...or.com>,
Peter Waskiewicz <peter.p.waskiewicz.jr@...el.com>,
netdev@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH 3/3] pch_gbe: Add MinnowBoard support
On Fri, 2013-07-12 at 17:58 -0700, Darren Hart wrote:
> The MinnowBoard uses an AR803x PHY with the PCH GBE which requires
> special handling. Use the MinnowBoard PCI Subsystem ID to detect this
> and add a pci_device_id.driver_data structure and functions to handle
> platform setup.
>
> The AR803x does not implement the RGMII 2ns TX clock delay in the trace
> routing nor via strapping. Add a detection method for the board and the
> PHY and enable the TX clock delay via the registers.
>
> This PHY will hibernate without link for 10 seconds. Ensure the PHY is
> awake for probe and then disable hibernation. A future improvement would
> be to convert pch_gbe to using PHYLIB and making sure we can wake the
> PHY at the necessary times rather than permanently disabling it.
Few comments below.
> --- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h
> +++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h
> @@ -582,6 +582,19 @@ struct pch_gbe_hw_stats {
> };
>
> /**
> + * struct pch_gbe_privdata - PCI Device ID driver data
> + * @phy_tx_clk_delay: Bool, configure the PHY TX delay in software
> + * @phy_disable_hibernate: Bool, disable PHY hibernation
> + * @platform_init: Platform initialization callback, called from
> + * probe, prio to PHY initialization.
> + */
> +struct pch_gbe_privdata {
> + bool phy_tx_clk_delay;
> + bool phy_disable_hibernate;
> + int(*platform_init)(struct pci_dev *pdev);
I don't like the platform_init() approach here.
I think here should be plain GPIO line number.
I'll explain below why.
> @@ -604,6 +617,7 @@ struct pch_gbe_hw_stats {
> * @rx_buffer_len: Receive buffer length
> * @tx_queue_len: Transmit queue length
> * @have_msi: PCI MSI mode flag
> + * @pch_gbe_privdata PCI Device ID driver_data
Missed colon.
> --- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
> +++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
> @@ -2635,6 +2638,9 @@ static int pch_gbe_probe(struct pci_dev *pdev,
> adapter->pdev = pdev;
> adapter->hw.back = adapter;
> adapter->hw.reg = pcim_iomap_table(pdev)[PCH_GBE_PCI_BAR];
> + adapter->pdata = (struct pch_gbe_privdata *)pci_id->driver_data;
> + if (adapter->pdata && adapter->pdata->platform_init)
> + adapter->pdata->platform_init(pdev);
Here perhaps you check pdata and GPIO line number (let's say != -1) and
call GPIO request helper.
> @@ -2720,9 +2730,47 @@ err_free_netdev:
> return ret;
> }
>
> +/* The AR803X PHY on the MinnowBoard requires a physical pin to be toggled to
> + * ensure it is awake for probe and init. Request the line and reset the PHY.
> + */
> +static int pch_gbe_minnow_platform_init(struct pci_dev *pdev)
> +{
> + int ret = 0;
> + int flags = GPIOF_DIR_OUT | GPIOF_INIT_HIGH | GPIOF_EXPORT;
> + int gpio = MINNOW_PHY_RESET_GPIO;
> +
> + ret = gpio_request_one(gpio, flags, "minnow_phy_reset");
> + if (ret){
> + dev_err(&pdev->dev,
> + "ERR: Can't request PHY reset GPIO line '%d'\n", gpio);
> + return ret;
> + }
> +
> + gpio_set_value(gpio, 0);
> + usleep_range(1250, 1500);
> + gpio_set_value(gpio, 1);
> + usleep_range(1250, 1500);
First of all, who is going to release gpio? Perhaps
devm_gpio_request_one?
Next is the name of the function, since you are resetting PHY, what if
you call it like pch_gbe_reset_by_gpio ?
> +
> + return ret;
> +}
And most important one is the ACPI case. As far as I understand Minnow
board supports / will support ACPI5 variant of device enumeration. In
such case the GPIO line will come in the ACPI resources. Moreover, you
will have no struct pci_dev. I highly recommend to rewrite this as a
generic helper, which takes GPIO line number as an input parameter and
does the job.
> +
> +static struct pch_gbe_privdata pch_gbe_minnow_privdata = {
> + .phy_tx_clk_delay = true,
> + .phy_disable_hibernate = true,
> + .platform_init = pch_gbe_minnow_platform_init,
> +};
> +
> static DEFINE_PCI_DEVICE_TABLE(pch_gbe_pcidev_id) = {
> {.vendor = PCI_VENDOR_ID_INTEL,
> .device = PCI_DEVICE_ID_INTEL_IOH1_GBE,
> + .subvendor = PCI_VENDOR_ID_CIRCUITCO,
> + .subdevice = PCI_SUBSYSTEM_ID_CIRCUITCO_MINNOWBOARD,
> + .class = (PCI_CLASS_NETWORK_ETHERNET << 8),
> + .class_mask = (0xFFFF00),
> + .driver_data = (unsigned long) &pch_gbe_minnow_privdata
> + },
> + {.vendor = PCI_VENDOR_ID_INTEL,
> + .device = PCI_DEVICE_ID_INTEL_IOH1_GBE,
> .subvendor = PCI_ANY_ID,
> .subdevice = PCI_ANY_ID,
> .class = (PCI_CLASS_NETWORK_ETHERNET << 8),
> --- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_phy.c
> +++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_phy.c
> @@ -277,4 +286,93 @@ void pch_gbe_phy_init_setting(struct pch_gbe_hw *hw)
> pch_gbe_phy_read_reg_miic(hw, PHY_PHYSP_CONTROL, &mii_reg);
> mii_reg |= PHYSP_CTRL_ASSERT_CRS_TX;
> pch_gbe_phy_write_reg_miic(hw, PHY_PHYSP_CONTROL, mii_reg);
> +
> + /* Setup a TX clock delay on certain platforms */
> + if (adapter->pdata->phy_tx_clk_delay)
> + pch_gbe_phy_tx_clk_delay(hw);
> +}
> +
> +/**
> + * pch_gbe_phy_tx_clk_delay - Setup TX clock delay via the PHY
> + * @hw: Pointer to the HW structure
> + * Returns
> + * 0: Successful.
> + * -EINVAL: Invalid argument.
> + */
> +int pch_gbe_phy_tx_clk_delay(struct pch_gbe_hw *hw)
> +{
> + /* The RGMII interface requires a ~2ns TX clock delay. This is typically
> + * done in layout with a longer trace or via PHY strapping, but can also
> + * be done via PHY configuration registers.
> + */
> + struct pch_gbe_adapter *adapter = pch_gbe_hw_to_adapter(hw);
> + u16 mii_reg;
> + int ret = 0;
No need to assign. Are you trying to shut (sparse?) warning?
> +
> + switch (hw->phy.id) {
> + case PHY_AR803X_ID:
> + netdev_dbg(adapter->netdev,
> + "Configuring AR803X PHY for 2ns TX clock delay\n");
> + pch_gbe_phy_read_reg_miic(hw, PHY_AR8031_DBG_OFF, &mii_reg);
> + ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_OFF,
> + PHY_AR8031_SERDES);
> + if (ret)
> + break;
> +
> + pch_gbe_phy_read_reg_miic(hw, PHY_AR8031_DBG_DAT, &mii_reg);
> + mii_reg |= PHY_AR8031_SERDES_TX_CLK_DLY;
> + ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_DAT,
> + mii_reg);
> + break;
> + default:
> + netdev_err(adapter->netdev,
> + "Unknown PHY (%x), could not set TX clock delay.\n",
> + hw->phy.id);
> + return -EINVAL;
> + }
> +
> + if (ret)
> + netdev_err(adapter->netdev,
> + "Could not configure tx clock delay for PHY.\n");
> + return ret;
> +}
> +
> +/**
> + * pch_gbe_phy_disable_hibernate - Disable the PHY low power state
> + * @hw: Pointer to the HW structure
> + * Returns
> + * 0: Successful.
> + * -EINVAL: Invalid argument.
> + */
> +int pch_gbe_phy_disable_hibernate(struct pch_gbe_hw *hw)
> +{
> + struct pch_gbe_adapter *adapter = pch_gbe_hw_to_adapter(hw);
> + u16 mii_reg;
> + int ret = 0;
Ditto.
> + switch (hw->phy.id) {
> + case PHY_AR803X_ID:
> + netdev_dbg(adapter->netdev,
> + "Disabling hibernation for AR803X PHY\n");
> + ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_OFF,
> + PHY_AR8031_HIBERNATE);
> + if (ret)
> + break;
> +
> + pch_gbe_phy_read_reg_miic(hw, PHY_AR8031_DBG_DAT, &mii_reg);
> + mii_reg &= ~PHY_AR8031_PS_HIB_EN;
> + ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_DAT,
> + mii_reg);
> + break;
> + default:
> + netdev_err(adapter->netdev,
> + "Unknown PHY (%x), could not disable hibernation\n",
> + hw->phy.id);
> + return -EINVAL;
> + }
> +
> + if (ret)
> + netdev_err(adapter->netdev,
> + "Could not disable PHY hibernation.\n");
> + return ret;
> }
--
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Intel Finland Oy
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