Re: [PATCH 1/2] phy: add lpc18xx usb otg phy driver

[Kishon Vijay Abraham I <kishon-l0cyMroinI0@public.gmane.org>]

Hi,

On Saturday 16 May 2015 10:57 PM, Joachim Eastwood wrote:
> Add PHY driver for the internal USB OTG PHY found on NXP
> LPC18xx and LPC43xx devices. This driver takes care of
> enabling the PHY in CREG (syscon) and setting the required
> clock frequency.
>
> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>   drivers/phy/Kconfig               |  11 +++
>   drivers/phy/Makefile              |   1 +
>   drivers/phy/phy-lpc18xx-usb-otg.c | 145 ++++++++++++++++++++++++++++++++++++++
>   3 files changed, 157 insertions(+)
>   create mode 100644 drivers/phy/phy-lpc18xx-usb-otg.c
>
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index a53bd5b52df9..e11fb9e3c760 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -52,6 +52,17 @@ config PHY_EXYNOS_MIPI_VIDEO
>   	  Support for MIPI CSI-2 and MIPI DSI DPHY found on Samsung S5P
>   	  and EXYNOS SoCs.
>
> +config PHY_LPC18XX_USB_OTG
> +	tristate "NXP LPC18xx/43xx SoC USB OTG PHY driver"
> +	depends on OF && (ARCH_LPC18XX || COMPILE_TEST)
> +	select GENERIC_PHY
> +	select MFD_SYSCON
> +	help
> +	  Enable this to support NXP LPC18xx/43xx internal USB OTG PHY.
> +
> +	  This driver is need for USB0 support on LPC18xx/43xx and takes
> +	  care of enabling and clock setup.
> +
>   config PHY_MVEBU_SATA
>   	def_bool y
>   	depends on ARCH_DOVE || MACH_DOVE || MACH_KIRKWOOD
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index f12625178780..b7251f3b9ef7 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)	+= phy-armada375-usb2.o
>   obj-$(CONFIG_BCM_KONA_USB2_PHY)		+= phy-bcm-kona-usb2.o
>   obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)	+= phy-exynos-dp-video.o
>   obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)	+= phy-exynos-mipi-video.o
> +obj-$(CONFIG_PHY_LPC18XX_USB_OTG)	+= phy-lpc18xx-usb-otg.o
>   obj-$(CONFIG_PHY_MVEBU_SATA)		+= phy-mvebu-sata.o
>   obj-$(CONFIG_PHY_MIPHY28LP) 		+= phy-miphy28lp.o
>   obj-$(CONFIG_PHY_MIPHY365X)		+= phy-miphy365x.o
> diff --git a/drivers/phy/phy-lpc18xx-usb-otg.c b/drivers/phy/phy-lpc18xx-usb-otg.c
> new file mode 100644
> index 000000000000..3a86e8f75e7e
> --- /dev/null
> +++ b/drivers/phy/phy-lpc18xx-usb-otg.c
> @@ -0,0 +1,145 @@
> +/*
> + * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
> + *
> + * Copyright (C) 2015 Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + *
> + * 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/clk.h>
> +#include <linux/err.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +/* USB OTG PHY register offset and bit in CREG */
> +#define LPC18XX_CREG_CREG0		0x004
> +# define LPC18XX_CREG_CREG0_USB0PHY	BIT(5)

don't prefer a space between # and define. Not a strong feeling though.
> +
> +struct lpc18xx_usb_otg_phy {
> +	struct phy *phy;
> +	struct clk *clk;
> +	struct regmap *reg;
> +};
> +
> +static int lpc18xx_usb_otg_phy_init(struct phy *phy)
> +{
> +	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
> +	int ret;
> +
> +	ret = clk_prepare(lpc->clk);
> +	if (ret)
> +		return ret;
> +
> +	/* The PHY must be clocked at 480 MHz */
> +	return clk_set_rate(lpc->clk, 480000000);
> +}
> +
> +static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
> +{
> +	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
> +
> +	clk_unprepare(lpc->clk);
> +
> +	return 0;
> +}
> +
> +static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
> +{
> +	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
> +	int ret;
> +
> +	ret = clk_enable(lpc->clk);
> +	if (ret)
> +		return ret;
> +
> +	/* The bit in CREG is cleared to enable the PHY */
> +	return regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
> +				  LPC18XX_CREG_CREG0_USB0PHY, 0);
> +}
> +
> +static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
> +{
> +	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
> +	int ret;
> +
> +	ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
> +				 LPC18XX_CREG_CREG0_USB0PHY,
> +				 LPC18XX_CREG_CREG0_USB0PHY);
> +	if (ret)
> +		return ret;
> +
> +	clk_disable(lpc->clk);
> +
> +	return 0;
> +}
> +
> +static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
> +	.init		= lpc18xx_usb_otg_phy_init,
> +	.exit		= lpc18xx_usb_otg_phy_exit,
> +	.power_on	= lpc18xx_usb_otg_phy_power_on,
> +	.power_off	= lpc18xx_usb_otg_phy_power_off,
> +	.owner		= THIS_MODULE,
> +};
> +
> +static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
> +{
> +	struct phy_provider *phy_provider;
> +	struct lpc18xx_usb_otg_phy *lpc;
> +
> +	lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
> +	if (!lpc)
> +		return -ENOMEM;
> +
> +	lpc->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg");
> +	if (IS_ERR(lpc->reg)) {
> +		dev_err(&pdev->dev, "failed to get syscon\n");
> +		return PTR_ERR(lpc->reg);
> +	}
> +
> +	lpc->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(lpc->clk)) {
> +		dev_err(&pdev->dev, "failed to get clock\n");
> +		return PTR_ERR(lpc->clk);
> +	}
> +
> +	lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
> +	if (IS_ERR(lpc->phy)) {
> +		dev_err(&pdev->dev, "failed to create PHY\n");
> +		return PTR_ERR(lpc->phy);
> +	}
> +
> +	phy_set_drvdata(lpc->phy, lpc);
> +
> +	phy_provider = devm_of_phy_provider_register(&pdev->dev,
> +						     of_phy_simple_xlate);
> +	if (IS_ERR(phy_provider))
> +		return PTR_ERR(phy_provider);
> +
> +	return 0;

replace it with return PTR_ERR_OR_ZERO(phy_provider);

Thanks
Kishon
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