RE: [PATCH v4 1/3] phy: rcar-gen3-usb2: Add R-Car Gen3 USB2 PHY driver

[Yoshihiro Shimoda]

Hi,

> Sent: Saturday, October 17, 2015 10:44 AM
> 
> Hi,
> 
> On Tuesday 13 October 2015 03:52 PM, Yoshihiro Shimoda wrote:
< snip >
> > diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> > index 7eb5859d..45c6131 100644
> > --- a/drivers/phy/Kconfig
> > +++ b/drivers/phy/Kconfig
> > @@ -118,6 +118,14 @@ config PHY_RCAR_GEN2
> >  	help
> >  	  Support for USB PHY found on Renesas R-Car generation 2 SoCs.
> >
> > +config PHY_RCAR_GEN3_USB2
> > +	tristate "Renesas R-Car generation 3 USB 2.0 PHY driver"
> > +	depends on OF
> > +	depends on ARCH_SHMOBILE
> 
> The depends on can be moved to a single line.

Thank you for the review!
I will fix this.

> > +	depends on GENERIC_PHY
> 
> all the PHY drivers inside drivers/phy directory use select PHY. Please
> use select here.

Oops, I will fix it.

> > +	help
> > +	  Support for USB 2.0 PHY found on Renesas R-Car generation 3 SoCs.
> > +
> >  config OMAP_CONTROL_PHY
> >  	tristate "OMAP CONTROL PHY Driver"
> >  	depends on ARCH_OMAP2PLUS || COMPILE_TEST
< snip >
> > diff --git a/drivers/phy/phy-rcar-gen3-usb2.c b/drivers/phy/phy-rcar-gen3-usb2.c
> > new file mode 100644
> > index 0000000..d90dfcf
> > --- /dev/null
> > +++ b/drivers/phy/phy-rcar-gen3-usb2.c
> 
> Add a MAINTAINER entry for this file if there is no one else.

I got it. I will add a MAINTAINER entry.

> > @@ -0,0 +1,240 @@
> > +/*
> > + * Renesas R-Car Gen3 for USB2.0 PHY driver
> > + *
> > + * Copyright (C) 2015 Renesas Electronics Corporation
> > + *
> > + * This is based on the phy-rcar-gen2 driver:
> > + * Copyright (C) 2014 Renesas Solutions Corp.
> > + * Copyright (C) 2014 Cogent Embedded, Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_address.h>
> > +#include <linux/phy/phy.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/spinlock.h>
> > +
> > +/******* USB2.0 Host registers (original offset is +0x200) *******/
> > +#define USB2_INT_ENABLE		0x000
> > +#define USB2_USBCTR		0x00c
> > +#define USB2_SPD_RSM_TIMSET	0x10c
> > +#define USB2_OC_TIMSET		0x110
> > +
> > +/* INT_ENABLE */
> > +#define USB2_INT_ENABLE_USBH_INTB_EN	BIT(2)
> > +#define USB2_INT_ENABLE_USBH_INTA_EN	BIT(1)
> > +#define USB2_INT_ENABLE_INIT		(USB2_INT_ENABLE_USBH_INTB_EN | \
> > +					 USB2_INT_ENABLE_USBH_INTA_EN)
> > +
> > +/* USBCTR */
> > +#define USB2_USBCTR_DIRPD	BIT(2)
> > +#define USB2_USBCTR_PLL_RST	BIT(1)
> > +
> > +/* SPD_RSM_TIMSET */
> > +#define USB2_SPD_RSM_TIMSET_INIT	0x014e029b
> > +
> > +/* OC_TIMSET */
> > +#define USB2_OC_TIMSET_INIT		0x000209ab
> > +
> > +/******* HSUSB registers (original offset is +0x100) *******/
> > +#define HSUSB_LPSTS			0x02
> > +#define HSUSB_UGCTRL2			0x84
> > +
> > +/* Low Power Status register (LPSTS) */
> > +#define HSUSB_LPSTS_SUSPM		0x4000
> > +
> > +/* USB General control register 2 (UGCTRL2) */
> > +#define HSUSB_UGCTRL2_MASK		0x00000031 /* bit[31:6] should be 0 */
> > +#define HSUSB_UGCTRL2_USB0SEL		0x00000030
> > +#define HSUSB_UGCTRL2_USB0SEL_HOST	0x00000010
> > +#define HSUSB_UGCTRL2_USB0SEL_HS_USB	0x00000020
> > +#define HSUSB_UGCTRL2_USB0SEL_OTG	0x00000030
> > +
> > +struct rcar_gen3_data {
> > +	void __iomem *base;
> > +	struct clk *clk;
> > +};
> > +
> > +struct rcar_gen3_chan {
> > +	struct rcar_gen3_data usb2;
> > +	struct rcar_gen3_data hsusb;
> > +	struct phy *phy;
> > +	spinlock_t lock;
> 
> Why do you need a spinlock? It seems like a single PHY phy-provider? Is
> it for future modifications?

I used this spinlock to protect updating some registers from CPU(s).
I will remove it if it is not really needed.

> > +};
> > +
> > +static int rcar_gen3_phy_usb2_init(struct phy *p)
> > +{
> > +	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
> > +	unsigned long flags;
> > +	void __iomem *usb2_base = channel->usb2.base;
> > +	void __iomem *hsusb_base = channel->hsusb.base;
> > +	u32 tmp;
> > +
> > +	spin_lock_irqsave(&channel->lock, flags);
> > +
> > +	/* Initialize USB2 part */
> > +	writel(USB2_INT_ENABLE_INIT, usb2_base + USB2_INT_ENABLE);
> > +	writel(USB2_SPD_RSM_TIMSET_INIT, usb2_base + USB2_SPD_RSM_TIMSET);
> > +	writel(USB2_OC_TIMSET_INIT, usb2_base + USB2_OC_TIMSET);
> > +
> > +	/* Initialize HSUSB part */
> > +	if (hsusb_base) {
> > +		/* TODO: support "OTG" mode */
> > +		tmp = readl(hsusb_base + HSUSB_UGCTRL2);
> > +		tmp = (tmp & ~HSUSB_UGCTRL2_USB0SEL) |
> > +		      HSUSB_UGCTRL2_USB0SEL_HOST;
> > +		writel(tmp & HSUSB_UGCTRL2_MASK, hsusb_base + HSUSB_UGCTRL2);
> > +	}
> > +
> > +	spin_unlock_irqrestore(&channel->lock, flags);
> > +
> > +	return 0;
> > +}
> > +
> > +static int rcar_gen3_phy_usb2_exit(struct phy *p)
> > +{
> > +	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
> > +
> > +	writel(0, channel->usb2.base + USB2_INT_ENABLE);
> > +
> > +	return 0;
> > +}
> > +
> > +static int rcar_gen3_phy_usb2_power_on(struct phy *p)
> > +{
> > +	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
> > +	void __iomem *usb2_base = channel->usb2.base;
> > +	void __iomem *hsusb_base = channel->hsusb.base;
> > +	unsigned long flags;
> > +	u32 tmp;
> > +
> > +	spin_lock_irqsave(&channel->lock, flags);
> > +
> > +	tmp = readl(usb2_base + USB2_USBCTR);
> > +	tmp |= USB2_USBCTR_PLL_RST;
> > +	writel(tmp, usb2_base + USB2_USBCTR);
> > +	tmp &= ~USB2_USBCTR_PLL_RST;
> > +	writel(tmp, usb2_base + USB2_USBCTR);
> > +
> > +	/*
> > +	 * TODO: To reduce power consuming, this driver should set the SUSPM
> > +	 *	after the PHY detects ID pin as peripheral.
> > +	 */
> > +	if (hsusb_base) {
> > +		/* Power on HSUSB PHY */
> > +		tmp = readw(hsusb_base + HSUSB_LPSTS);
> > +		tmp |= HSUSB_LPSTS_SUSPM;
> > +		writew(tmp, hsusb_base + HSUSB_LPSTS);
> > +	}
> > +
> > +	spin_unlock_irqrestore(&channel->lock, flags);
> > +
> > +	return 0;
> > +}
> > +
> > +static int rcar_gen3_phy_usb2_power_off(struct phy *p)
> > +{
> > +	struct rcar_gen3_chan *channel = phy_get_drvdata(p);
> > +	void __iomem *hsusb_base = channel->hsusb.base;
> > +	unsigned long flags;
> > +	u32 tmp;
> > +
> > +	spin_lock_irqsave(&channel->lock, flags);
> > +
> > +	if (hsusb_base) {
> > +		/* Power off HSUSB PHY */
> > +		tmp = readw(hsusb_base + HSUSB_LPSTS);
> > +		tmp &= ~HSUSB_LPSTS_SUSPM;
> > +		writew(tmp, hsusb_base + HSUSB_LPSTS);
> > +	}
> > +
> > +	spin_unlock_irqrestore(&channel->lock, flags);
> > +
> > +	return 0;
> > +}
> > +
> > +static struct phy_ops rcar_gen3_phy_usb2_ops = {
> > +	.init		= rcar_gen3_phy_usb2_init,
> > +	.exit		= rcar_gen3_phy_usb2_exit,
> > +	.power_on	= rcar_gen3_phy_usb2_power_on,
> > +	.power_off	= rcar_gen3_phy_usb2_power_off,
> > +	.owner		= THIS_MODULE,
> > +};
> > +
> > +static const struct of_device_id rcar_gen3_phy_usb2_match_table[] = {
> > +	{ .compatible = "renesas,usb2-phy-r8a7795" },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb2_match_table);
> > +
> > +static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct rcar_gen3_chan *channel;
> > +	struct phy_provider *provider;
> > +	struct resource *res;
> > +
> > +	if (!dev->of_node) {
> > +		dev_err(dev, "This driver needs device tree\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL);
> > +	if (!channel)
> > +		return -ENOMEM;
> > +
> > +	spin_lock_init(&channel->lock);
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "usb2_host");
> > +	channel->usb2.base = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(channel->usb2.base))
> > +		return PTR_ERR(channel->usb2.base);
> > +
> > +	/* "hsusb" memory resource is optional */
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hsusb");
> > +
> > +	/* To avoid error message by devm_ioremap_resource() */
> > +	if (res) {
> > +		channel->hsusb.base = devm_ioremap_resource(dev, res);
> > +		if (IS_ERR(channel->hsusb.base))
> > +			channel->hsusb.base = NULL;
> > +	}
> > +
> > +	/* devm_phy_create() will call pm_runtime_enable(dev); */
> > +	channel->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb2_ops);
> > +	if (IS_ERR(channel->phy)) {
> > +		dev_err(dev, "Failed to create USB2 PHY\n");
> > +		return PTR_ERR(channel->phy);
> > +	}
> > +
> > +	phy_set_drvdata(channel->phy, channel);
> > +
> > +	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> > +	if (IS_ERR(provider)) {
> > +		dev_err(dev, "Failed to register PHY provider\n");
> > +		return PTR_ERR(provider);
> > +	}
> > +
> > +	dev_set_drvdata(dev, channel);
> 
> This looks unnecessary and if you remove that you can use return
> PTR_ERR_OR_ZERO.

Thank you for the point. I will remove it.

Best regards,
Yoshihiro Shimoda

> Thanks
> Kishon
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