Re: [PATCH v3 2/2] phy: cygnus: pcie: Add Cygnus PCIe PHY support

From: Kishon Vijay Abraham I
Date: Fri Sep 18 2015 - 02:22:50 EST


Hi,

On Tuesday 15 September 2015 11:26 PM, Ray Jui wrote:
> This patch adds the PCIe PHY support for the Broadcom PCIe RC interface
> on Cygnus
>
> Signed-off-by: Ray Jui <rjui@xxxxxxxxxxxx>
> Reviewed-by: Arun Parameswaran <aparames@xxxxxxxxxxxx>
> Reviewed-by: JD (Jiandong) Zheng <jdzheng@xxxxxxxxxxxx>
> Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
> ---
> drivers/phy/Kconfig | 9 ++
> drivers/phy/Makefile | 1 +
> drivers/phy/phy-bcm-cygnus-pcie.c | 198 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 208 insertions(+)
> create mode 100644 drivers/phy/phy-bcm-cygnus-pcie.c
>
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 47da573..947bae2 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -371,4 +371,13 @@ config PHY_BRCMSTB_SATA
> Enable this to support the SATA3 PHY on 28nm Broadcom STB SoCs.
> Likely useful only with CONFIG_SATA_BRCMSTB enabled.
>
> +config PHY_CYGNUS_PCIE
> + tristate "Broadcom Cygnus PCIe PHY driver"
> + depends on OF && (ARCH_BCM_CYGNUS || COMPILE_TEST)
> + select GENERIC_PHY
> + default ARCH_BCM_CYGNUS
> + help
> + Enable this to support the Broadcom Cygnus PCIe PHY.
> + If unsure, say N.
> +
> endmenu
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index a5b18c1..fdce78d 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -46,3 +46,4 @@ obj-$(CONFIG_PHY_QCOM_UFS) += phy-qcom-ufs-qmp-14nm.o
> obj-$(CONFIG_PHY_TUSB1210) += phy-tusb1210.o
> obj-$(CONFIG_PHY_BRCMSTB_SATA) += phy-brcmstb-sata.o
> obj-$(CONFIG_PHY_PISTACHIO_USB) += phy-pistachio-usb.o
> +obj-$(CONFIG_PHY_CYGNUS_PCIE) += phy-bcm-cygnus-pcie.o
> diff --git a/drivers/phy/phy-bcm-cygnus-pcie.c b/drivers/phy/phy-bcm-cygnus-pcie.c
> new file mode 100644
> index 0000000..0fb6750
> --- /dev/null
> +++ b/drivers/phy/phy-bcm-cygnus-pcie.c
> @@ -0,0 +1,198 @@
> +/*
> + * Copyright (C) 2015 Broadcom Corporation
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation version 2.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +
> +#define PCIE_CFG_OFFSET 0x00
> +#define PCIE1_PHY_IDDQ_SHIFT 10
> +#define PCIE0_PHY_IDDQ_SHIFT 2
> +
> +enum cygnus_pcie_phy_id {
> + CYGNUS_PHY_PCIE0 = 0,
> + CYGNUS_PHY_PCIE1,
> + MAX_NUM_PHYS,
> +};
> +
> +struct cygnus_pcie_phy_core;
> +
> +/**
> + * struct cygnus_pcie_phy - Cygnus PCIe PHY device
> + * @core: pointer to the Cygnus PCIe PHY core control
> + * @id: internal ID to identify the Cygnus PCIe PHY
> + * @phy: pointer to the kernel PHY device
> + */
> +struct cygnus_pcie_phy {
> + struct cygnus_pcie_phy_core *core;
> + enum cygnus_pcie_phy_id id;
> + struct phy *phy;
> +};
> +
> +/**
> + * struct cygnus_pcie_phy_core - Cygnus PCIe PHY core control
> + * @dev: pointer to device
> + * @base: base register
> + * @lock: mutex to protect access to individual PHYs
> + * @phys: pointer to Cygnus PHY device
> + */
> +struct cygnus_pcie_phy_core {
> + struct device *dev;
> + void __iomem *base;
> + struct mutex lock;
> + struct cygnus_pcie_phy phys[MAX_NUM_PHYS];
> +};
> +
> +static int cygnus_pcie_power_config(struct cygnus_pcie_phy *phy, bool enable)
> +{
> + struct cygnus_pcie_phy_core *core = phy->core;
> + unsigned shift;
> + u32 val;
> +
> + mutex_lock(&core->lock);
> +
> + switch (phy->id) {
> + case CYGNUS_PHY_PCIE0:
> + shift = PCIE0_PHY_IDDQ_SHIFT;
> + break;
> +
> + case CYGNUS_PHY_PCIE1:
> + shift = PCIE1_PHY_IDDQ_SHIFT;
> + break;
> +
> + default:
> + mutex_unlock(&core->lock);
> + dev_err(core->dev, "PCIe PHY id%d invalid\n", phy->id);
> + return -EINVAL;
> + }
> +
> + if (enable) {
> + val = readl(core->base + PCIE_CFG_OFFSET);
> + val &= ~BIT(shift);
> + writel(val, core->base + PCIE_CFG_OFFSET);
> + msleep(50);
> + } else {
> + val = readl(core->base + PCIE_CFG_OFFSET);
> + val |= BIT(shift);
> + writel(val, core->base + PCIE_CFG_OFFSET);
> + }
> +
> + mutex_unlock(&core->lock);
> + dev_info(core->dev, "PCIe PHY %s\n", enable ? "enabled" : "disabled");
> + return 0;
> +}
> +
> +static int cygnus_pcie_phy_power_on(struct phy *p)
> +{
> + struct cygnus_pcie_phy *phy = phy_get_drvdata(p);
> +
> + return cygnus_pcie_power_config(phy, true);
> +}
> +
> +static int cygnus_pcie_phy_power_off(struct phy *p)
> +{
> + struct cygnus_pcie_phy *phy = phy_get_drvdata(p);
> +
> + return cygnus_pcie_power_config(phy, false);
> +}
> +
> +static struct phy_ops cygnus_pcie_phy_ops = {
> + .power_on = cygnus_pcie_phy_power_on,
> + .power_off = cygnus_pcie_phy_power_off,

.owner is required here.
> +};
> +
> +static struct phy *cygnus_pcie_phy_xlate(struct device *dev,
> + struct of_phandle_args *args)
> +{
> + struct cygnus_pcie_phy_core *core;
> + int id;
> +
> + core = dev_get_drvdata(dev);
> + if (!core)
> + return ERR_PTR(-EINVAL);
> +
> + id = args->args[0];
> +
> + if (WARN_ON(id >= MAX_NUM_PHYS))
> + return ERR_PTR(-ENODEV);
> +
> + return core->phys[id].phy;
> +}
> +
> +static int cygnus_pcie_phy_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct cygnus_pcie_phy_core *core;
> + struct phy_provider *provider;
> + struct resource *res;
> + int i = 0;
> +
> + core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
> + if (!core)
> + return -ENOMEM;
> +
> + core->dev = dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + core->base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(core->base))
> + return PTR_ERR(core->base);
> +
> + mutex_init(&core->lock);
> +
> + for (i = 0; i < MAX_NUM_PHYS; i++) {

Don't have to hard code MAX_NUM_PHYS. This can be modelled in dt itself.
Create a single PHY provider node and model each individual PHYs as the
child node of the PHY provider.
> + struct cygnus_pcie_phy *p = &core->phys[i];
> +
> + p->phy = devm_phy_create(dev, NULL, &cygnus_pcie_phy_ops);
> + if (IS_ERR(p->phy)) {
> + dev_err(dev, "failed to create PHY\n");
> + return PTR_ERR(p->phy);
> + }
> +
> + p->core = core;
> + p->id = i;
> + phy_set_drvdata(p->phy, p);
> + }
> +
> + dev_set_drvdata(dev, core);
> +
> + provider = devm_of_phy_provider_register(dev, cygnus_pcie_phy_xlate);

this custom xlate function is not required at all.

Thanks
Kishon
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