Re: [PATCH v2 2/4] phy: add inno-usb2-phy driver for hi3798cv200 SoC

[Kishon Vijay Abraham I]

Hi,

On Wednesday 26 July 2017 11:36 AM, Jiancheng Xue wrote:
> From: Pengcheng Li <lpc.li@xxxxxxxxxxxxx>
> 
> Add inno-usb2-phy driver for hi3798cv200 SoC.
> 
> Signed-off-by: Pengcheng Li <lpc.li@xxxxxxxxxxxxx>
> Signed-off-by: Jiancheng Xue <xuejiancheng@xxxxxxxxxxxxx>
> ---
>  drivers/phy/hisilicon/Kconfig              |  11 +-
>  drivers/phy/hisilicon/Makefile             |   1 +
>  drivers/phy/hisilicon/phy-hisi-inno-usb2.c | 236 +++++++++++++++++++++++++++++
>  3 files changed, 247 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/phy/hisilicon/phy-hisi-inno-usb2.c
> 
> diff --git a/drivers/phy/hisilicon/Kconfig b/drivers/phy/hisilicon/Kconfig
> index 6164c4c..6a675c5 100644
> --- a/drivers/phy/hisilicon/Kconfig
> +++ b/drivers/phy/hisilicon/Kconfig
> @@ -8,9 +8,18 @@ config PHY_HI6220_USB
>  	select MFD_SYSCON
>  	help
>  	  Enable this to support the HISILICON HI6220 USB PHY.
> -
  ^^
not related to $patch.
>  	  To compile this driver as a module, choose M here.
>  
> +config PHY_HISI_INNO_USB2
> +       tristate "HiSilicon INNO USB2 PHY support"
> +       depends on (ARCH_HISI) || COMPILE_TEST
> +       select GENERIC_PHY
> +       select MFD_SYSCON
> +       help
> +         Support for INNO USB2 PHY on HiSilicon SoCs. This Phy supports
> +         USB 1.5Mb/s, USB 12Mb/s, USB 480Mb/s speeds. It supports one
> +         USB host port to accept one USB device.
> +
>  config PHY_HIX5HD2_SATA
>  	tristate "HIX5HD2 SATA PHY Driver"
>  	depends on ARCH_HIX5HD2 && OF && HAS_IOMEM
> diff --git a/drivers/phy/hisilicon/Makefile b/drivers/phy/hisilicon/Makefile
> index 541b348..e6c9794 100644
> --- a/drivers/phy/hisilicon/Makefile
> +++ b/drivers/phy/hisilicon/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_PHY_HI6220_USB)		+= phy-hi6220-usb.o
> +obj-$(CONFIG_PHY_HISI_INNO_USB2)	+= phy-hisi-inno-usb2.o
>  obj-$(CONFIG_PHY_HIX5HD2_SATA)		+= phy-hix5hd2-sata.o
> diff --git a/drivers/phy/hisilicon/phy-hisi-inno-usb2.c b/drivers/phy/hisilicon/phy-hisi-inno-usb2.c
> new file mode 100644
> index 0000000..7edf4a3
> --- /dev/null
> +++ b/drivers/phy/hisilicon/phy-hisi-inno-usb2.c
> @@ -0,0 +1,236 @@
> +/*
> + * HiSilicon INNO USB2 PHY Driver.
> + *
> + * Copyright (c) 2016-2017 HiSilicon Technologies Co., Ltd.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#define INNO_PHY_PORT_NUM	2
> +#define REF_CLK_STABLE_TIME	100	/* unit:us */
> +#define UTMI_CLK_STABLE_TIME	200	/* unit:us */
> +#define TEST_CLK_STABLE_TIME	2	/* unit:ms */
> +#define PHY_CLK_STABLE_TIME	2	/* unit:ms */
> +#define UTMI_RST_COMPLETE_TIME	2	/* unit:ms */
> +#define TEST_RST_COMPLETE_TIME	100	/* unit:us */
> +#define POR_RST_COMPLETE_TIME	300	/* unit:us */
> +#define PHY_TEST_DATA	GENMASK(7, 0)
> +#define PHY_TEST_ADDR	GENMASK(15, 8)
> +#define PHY_TEST_PORT	GENMASK(18, 16)
> +#define PHY_TEST_WREN	BIT(21)
> +#define PHY_TEST_CLK	BIT(22)	/* rising edge active */
> +#define PHY_TEST_RST	BIT(23)	/* low active */
> +#define PHY_CLK_ENABLE	BIT(2)
> +
> +struct hisi_inno_phy_priv {
> +	struct regmap *syscon;
> +	u32 reg;
> +	struct clk *ref_clk;
> +	struct reset_control *por_rst;
> +	struct reset_control *test_rst;
> +	struct reset_control *utmi_rst[INNO_PHY_PORT_NUM];
> +	u32 port_num;
> +};
> +
> +static void hisi_inno_phy_write_reg(struct regmap *syscon,
> +			u32 reg, u8 port, u32 addr, u32 data)
> +{
> +	u32 value;
> +
> +	value = (data & PHY_TEST_DATA)
> +		| ((addr << 8) & PHY_TEST_ADDR)
> +		| ((port << 16) & PHY_TEST_PORT)
> +		| PHY_TEST_WREN | PHY_TEST_RST;
> +	regmap_write(syscon, reg, value);
> +	value |= PHY_TEST_CLK;
> +	regmap_write(syscon, reg, value);
> +	value &= ~PHY_TEST_CLK;
> +	regmap_write(syscon, reg, value);
> +}
> +
> +static void hisi_inno_phy_setup(struct hisi_inno_phy_priv *priv)
> +{
> +	/* The phy clk is controlled by the port0 register 0x06. */
> +	hisi_inno_phy_write_reg(priv->syscon,
> +			priv->reg, 0, 0x06, PHY_CLK_ENABLE);
> +	msleep(PHY_CLK_STABLE_TIME);
> +}
> +
> +static int hisi_inno_phy_init(struct phy *phy)
> +{
> +	struct hisi_inno_phy_priv *priv = phy_get_drvdata(phy);
> +	int ret, i;
> +
> +	ret = clk_prepare_enable(priv->ref_clk);
> +	if (ret)
> +		return ret;
> +	udelay(REF_CLK_STABLE_TIME);
> +
> +	if (priv->test_rst) {
> +		reset_control_deassert(priv->test_rst);
> +		udelay(TEST_RST_COMPLETE_TIME);
> +	}
> +
> +	reset_control_deassert(priv->por_rst);
> +	udelay(POR_RST_COMPLETE_TIME);
> +
> +	/* config phy clk and phy eye diagram */
> +	hisi_inno_phy_setup(priv);
> +
> +	for (i = 0; i < priv->port_num; i++) {
> +		reset_control_deassert(priv->utmi_rst[i]);
> +		udelay(UTMI_RST_COMPLETE_TIME);
> +	}
> +
> +	return 0;
> +}
> +
> +static void hisi_inno_phy_disable(struct phy *phy)
> +{
> +	struct hisi_inno_phy_priv *priv = phy_get_drvdata(phy);
> +	int i;
> +
> +	for (i = 0; i < priv->port_num; i++)
> +		reset_control_assert(priv->utmi_rst[i]);
> +
> +	reset_control_assert(priv->por_rst);
> +	if (priv->test_rst)
> +		reset_control_assert(priv->test_rst);
> +	clk_disable_unprepare(priv->ref_clk);
> +}
> +
> +static int hisi_inno_phy_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct phy *phy;
> +	struct hisi_inno_phy_priv *priv;
> +	struct device_node *node = dev->of_node;
> +	int ret, i;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->syscon = syscon_regmap_lookup_by_phandle(node,
> +			"hisilicon,peripheral-syscon");
> +	if (IS_ERR(priv->syscon)) {
> +		dev_err(dev, "no hisilicon,peripheral-syscon\n");
> +		return PTR_ERR(priv->syscon);
> +	}
> +
> +	ret = device_property_read_u32(dev,
> +			"hisilicon,phycon-reg", &priv->reg);
> +	if (ret)
> +		return ret;
> +
> +	priv->ref_clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(priv->ref_clk))
> +		return PTR_ERR(priv->ref_clk);
> +
> +	priv->por_rst = devm_reset_control_get_exclusive(dev, "power_on");
> +	if (IS_ERR(priv->por_rst))
> +		return PTR_ERR(priv->por_rst);
> +
> +	ret = device_property_read_u32(dev,
> +					"hisilicon,port-num", &priv->port_num);
> +	if (ret)
> +		return ret;
> +
> +	if (priv->port_num <= 0
> +		|| priv->port_num > INNO_PHY_PORT_NUM)
> +		return -EINVAL;
> +
> +	for (i = 0; i < priv->port_num; i++) {
> +		char id[6];
> +
> +		snprintf(id, 6, "utmi%1d\n", i);
> +		priv->utmi_rst[i] = devm_reset_control_get_exclusive(dev, id);
> +		if (IS_ERR(priv->utmi_rst[i]))
> +			return PTR_ERR(priv->utmi_rst[i]);
> +	}
> +
> +	priv->test_rst = devm_reset_control_get_optional_exclusive(dev, "test");
> +	if (IS_ERR(priv->test_rst))
> +		return PTR_ERR(priv->test_rst);
> +
> +	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
> +	if (!phy)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, phy);
> +	phy_set_drvdata(phy, priv);
> +
> +	return hisi_inno_phy_init(phy);

why don't you use the phy framework and initialize the phy only when required
by the usb host controller?
> +}
> +
> +static int hisi_inno_phy_remove(struct platform_device *pdev)
> +{
> +	struct phy *phy = platform_get_drvdata(pdev);
> +
> +	hisi_inno_phy_disable(phy);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int hisi_inno_phy_suspend(struct device *dev)
> +{
> +	struct phy *phy = dev_get_drvdata(dev);
> +
> +	hisi_inno_phy_disable(phy);

How do you make sure, usb is not using the phy when suspend is invoked? We
don't want to be disabling the phy when usb controller is using it.

Thanks
Kishon