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Message-ID: <550011B1.5010706@ti.com>
Date: Wed, 11 Mar 2015 15:28:09 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Tony Lindgren <tony@...mide.com>
CC: <linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>,
linux-usb <linux-usb@...r.kernel.org>,
Brian Hutchinson <b.hutchman@...il.com>,
Felipe Balbi <balbi@...com>
Subject: Re: [PATCH] phy: Add a driver for dm816x USB PHY
Hi Tony,
On Tuesday 10 March 2015 02:21 AM, Tony Lindgren wrote:
> Add a minimal driver for dm816x USB. Otherwise we can just use
> the existing musb_am335x and musb_dsps on dm816x.
If we can use an existing driver, I'd prefer that.
>
> Cc: Brian Hutchinson <b.hutchman@...il.com>
> Cc: Felipe Balbi <balbi@...com>
> Signed-off-by: Tony Lindgren <tony@...mide.com>
>
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/dm816x-phy.txt
> @@ -0,0 +1,24 @@
> +Device tree binding documentation for am816x USB PHY
> +=========================
> +
> +Required properties:
> +- compatible : should be "ti,dm816x-usb-phy"
> +- reg : offset and length of the PHY register set.
> +- reg-names : name for the phy registers
> +- clocks : phandle to the clock
> +- clock-names : name of the clock
> +- syscon: phandle for the syscon node to access misc registers
> +- #phy-cells : from the generic PHY bindings, must be 1
> +- syscon: phandle for the syscon node to access misc registers
> +
> +Example:
> +
> +usb_phy0: usb-phy@20 {
> + compatible = "ti,dm8168-usb-phy";
> + reg = <0x20 0x8>;
> + reg-names = "phy";
> + clocks = <&main_fapll 6>;
> + clock-names = "refclk";
> + #phy-cells = <0>;
> + syscon = <&scm_conf>;
> +};
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -35,6 +35,13 @@ config ARMADA375_USBCLUSTER_PHY
> depends on OF
> select GENERIC_PHY
>
> +config PHY_DM816X_USB
> + tristate "TI dm816x USB PHY driver"
> + depends on ARCH_OMAP2PLUS
> + select GENERIC_PHY
> + help
> + Enable this for dm81xx USB to work."
> +
> config PHY_EXYNOS_MIPI_VIDEO
> tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
> depends on HAS_IOMEM
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -5,6 +5,7 @@
> obj-$(CONFIG_GENERIC_PHY) += phy-core.o
> obj-$(CONFIG_PHY_BERLIN_USB) += phy-berlin-usb.o
> obj-$(CONFIG_PHY_BERLIN_SATA) += phy-berlin-sata.o
> +obj-$(CONFIG_PHY_DM816X_USB) += phy-dm816x-usb.o
> obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY) += phy-armada375-usb2.o
> obj-$(CONFIG_BCM_KONA_USB2_PHY) += phy-bcm-kona-usb2.o
> obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO) += phy-exynos-dp-video.o
> --- /dev/null
> +++ b/drivers/phy/phy-dm816x-usb.c
> @@ -0,0 +1,295 @@
> +/*
> + * 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; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/io.h>
> +#include <linux/usb/phy_companion.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/delay.h>
> +#include <linux/phy/phy.h>
> +#include <linux/of_platform.h>
> +
> +#include <linux/mfd/syscon.h>
> +
> +/*
> + * TRM has two sets of USB_CTRL registers.. The correct register bits
> + * are in TRM section 24.9.8.2 USB_CTRL Register.
> + */
> +#define DM816X_USB_CTRL_PHYCLKSRC BIT(8) /* 1 = PLL ref clock */
> +#define DM816X_USB_CTRL_PHYSLEEP1 BIT(1)
> +#define DM816X_USB_CTRL_PHYSLEEP0 BIT(0)
> +
> +#define DM816X_USBPHY_CTRL_TXRISETUNE 1
> +#define DM816X_USBPHY_CTRL_TXVREFTUNE 0xc
> +#define DM816X_USBPHY_CTRL_TXPREEMTUNE 0x2
> +
> +struct dm816x_usb_phy {
> + struct regmap *syscon;
> + struct device *dev;
> + unsigned int instance;
> + struct clk *refclk;
> + struct usb_phy phy;
> + unsigned int usb_ctrl; /* Shared between phy0 and phy1 */
> + unsigned int usbphy_ctrl;
> +};
> +
> +static int dm816x_usb_phy_set_host(struct usb_otg *otg, struct usb_bus *host)
> +{
> + otg->host = host;
> + if (!host)
> + otg->state = OTG_STATE_UNDEFINED;
> +
> + return 0;
> +}
> +
> +static int dm816x_usb_phy_set_peripheral(struct usb_otg *otg,
> + struct usb_gadget *gadget)
> +{
> + otg->gadget = gadget;
> + if (!gadget)
> + otg->state = OTG_STATE_UNDEFINED;
> +
> + return 0;
> +}
> +
> +static int dm816x_usb_phy_power_off(struct phy *x)
> +{
> + struct dm816x_usb_phy *phy = phy_get_drvdata(x);
> +
> + pm_runtime_put(phy->dev);
phy core takes care of invoking pm_runtime_put on power_off.
So this function shouldn't be needed at all.
> +
> + return 0;
> +}
> +
> +static int dm816x_usb_phy_power_on(struct phy *x)
> +{
> + struct dm816x_usb_phy *phy = phy_get_drvdata(x);
> +
> + return pm_runtime_get_sync(phy->dev);
similarly on power_on, phy_core invokes pm_runtime_get_sync.
> +}
> +
> +static int dm816x_usb_phy_init(struct phy *x)
> +{
> + struct dm816x_usb_phy *phy = phy_get_drvdata(x);
> + unsigned int val;
> + int error;
> +
> + error = pm_runtime_get_sync(phy->dev);
> + if (error)
> + return error;
not required.
> +
> + if (clk_get_rate(phy->refclk) != 24000000)
> + dev_warn(phy->dev, "nonstandard phy refclk\n");
> +
> + /* Set PLL ref clock and put phys to sleep */
> + error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
> + DM816X_USB_CTRL_PHYCLKSRC |
> + DM816X_USB_CTRL_PHYSLEEP1 |
> + DM816X_USB_CTRL_PHYSLEEP0,
> + 0);
> + regmap_read(phy->syscon, phy->usb_ctrl, &val);
> +
> + /*
> + * TI kernel sets these values for "symmetrical eye diagram and
> + * better signal quality" so let's assume somebody checked the
> + * values with a scope and set them here too.
> + */
> + regmap_read(phy->syscon, phy->usbphy_ctrl, &val);
> + val |= DM816X_USBPHY_CTRL_TXRISETUNE |
> + DM816X_USBPHY_CTRL_TXVREFTUNE |
> + DM816X_USBPHY_CTRL_TXPREEMTUNE;
> + regmap_write(phy->syscon, phy->usbphy_ctrl, val);
> +
> + pm_runtime_put(phy->dev);
same here.
> +
> + return 0;
> +}
> +
> +static struct phy_ops ops = {
> + .init = dm816x_usb_phy_init,
> + .power_on = dm816x_usb_phy_power_on,
> + .power_off = dm816x_usb_phy_power_off,
> + .owner = THIS_MODULE,
> +};
> +
> +static int dm816x_usb_phy_runtime_suspend(struct device *dev)
> +{
> + struct dm816x_usb_phy *phy = dev_get_drvdata(dev);
> + unsigned int mask, val;
> + int error = 0;
> +
> + mask = BIT(phy->instance);
> + val = ~BIT(phy->instance);
> + error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
> + mask, val);
> + if (error)
> + dev_err(phy->dev, "phy%i failed to power off\n",
> + phy->instance);
> + clk_disable(phy->refclk);
> +
> + return 0;
> +}
> +
> +static int dm816x_usb_phy_runtime_resume(struct device *dev)
> +{
> + struct dm816x_usb_phy *phy = dev_get_drvdata(dev);
> + unsigned int mask, val;
> + int error;
> +
> + error = clk_enable(phy->refclk);
> + if (error)
> + return error;
> +
> + mask = BIT(phy->instance);
> + val = BIT(phy->instance);
> + error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
> + mask, val);
> + if (error) {
> + dev_err(phy->dev, "phy%i failed to power on\n",
> + phy->instance);
> + clk_disable(phy->refclk);
> + return error;
> + }
> +
> + return 0;
> +}
> +
> +static UNIVERSAL_DEV_PM_OPS(dm816x_usb_phy_pm_ops,
> + dm816x_usb_phy_runtime_suspend,
> + dm816x_usb_phy_runtime_resume,
> + NULL);
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id dm816x_usb_phy_id_table[] = {
> + {
> + .compatible = "ti,dm8168-usb-phy",
> + },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, dm816x_usb_phy_id_table);
> +#endif
> +
> +static int dm816x_usb_phy_probe(struct platform_device *pdev)
> +{
> + struct dm816x_usb_phy *phy;
> + struct resource *res;
> + struct phy *generic_phy;
> + struct phy_provider *phy_provider;
> + struct usb_otg *otg;
> + const struct of_device_id *of_id;
> + const struct usb_phy_data *phy_data;
> + int error;
> +
> + of_id = of_match_device(of_match_ptr(dm816x_usb_phy_id_table),
> + &pdev->dev);
> + if (!of_id)
> + return -EINVAL;
> +
> + phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
> + if (!phy)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENOENT;
> +
> + phy->syscon = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> + "syscon");
> + if (IS_ERR(phy->syscon))
> + return PTR_ERR(phy->syscon);
> +
> + /*
> + * According to sprs614e.pdf, the first usb_ctrl is shared and
> + * the second instance for usb_ctrl is reserved.. Also the
> + * register bits are different from earlier TRMs.
> + */
> + phy->usb_ctrl = 0x20;
> + phy->usbphy_ctrl = (res->start & 0xff) + 4;
> + if (phy->usbphy_ctrl == 0x2c)
> + phy->instance = 1;
> +
> + phy_data = of_id->data;
> +
> + otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
> + if (!otg)
> + return -ENOMEM;
> +
> + phy->dev = &pdev->dev;
> + phy->phy.dev = phy->dev;
> + phy->phy.label = "dm8168_usb_phy";
> + phy->phy.otg = otg;
> + phy->phy.type = USB_PHY_TYPE_USB2;
> + otg->set_host = dm816x_usb_phy_set_host;
> + otg->set_peripheral = dm816x_usb_phy_set_peripheral;
> + otg->usb_phy = &phy->phy;
> +
> + platform_set_drvdata(pdev, phy);
> +
> + phy->refclk = devm_clk_get(phy->dev, "refclk");
> + if (IS_ERR(phy->refclk))
> + return PTR_ERR(phy->refclk);
> +
> + generic_phy = devm_phy_create(phy->dev, NULL, &ops);
> + if (IS_ERR(generic_phy))
> + return PTR_ERR(generic_phy);
Just invoke pm_runtime_enable before phy_create and phy core will take care of
invoking all pm_runtime functions at appropriate time.
Cheers
Kishon
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