Subject: [PATCH v2] ARM: sunxi: Add driver for sunxi usb phy

From: [email-masked] (Hans de Goede)
Date: Sat, 08 Feb 2014 00:27:42 +0100

Hi,

On 02/07/2014 11:36 PM, Maxime Ripard wrote:
> Hi Hans,
>
> It looks very nice, I just have a few comments below though.
>
> On Fri, Feb 07, 2014 at 05:33:21PM +0100, Hans de Goede wrote:
>> The Allwinner A1x / A2x SoCs have 2 or 3 usb phys which are all accessed
>> through a single set of registers. Besides this there are also some other
>> phy related bits which need poking, which are per phy, but shared between the
>> ohci and ehci controllers, so these are also controlled from this new phy
>> driver.
>>
>> Signed-off-by: Hans de Goede <[email-masked]>
>> ---
>>   .../devicetree/bindings/phy/sun4i-usb-phy.txt      |  28 ++
>>   drivers/phy/Kconfig                                |  11 +
>>   drivers/phy/Makefile                               |   1 +
>>   drivers/phy/phy-sun4i-usb.c                        | 326 +++++++++++++++++++++
>>   4 files changed, 366 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt
>>   create mode 100644 drivers/phy/phy-sun4i-usb.c
>>
>> diff --git a/Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt b/Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt
>> new file mode 100644
>> index 0000000..f7eccb2
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt
>> @@ -0,0 +1,28 @@
>> +Allwinner sun4i USB PHY
>> +-----------------------
>> +
>> +Required properties:
>> +- compatible : should be one of "allwinner,sun4i-a10-usb-phy",
>> +  "allwinner,sun5i-a13-usb-phy" or "allwinner,sun7i-a20-usb-phy"
>> +- reg : a list of offset + length pairs, the 1st list entry should point to
>> +  the phy base regs, the 2nd entry to the pmu reg for phy1, and the 3th
>> +  entry to the pmu reg of phy2 (for devices which have a phy2).
>
> I'm concerned about devices that would only have a phy2 for some
> reason.

phy1 and phy2 are identical, so in that case we would just call the phy
phy1 I guess, and specify its register where ever it lives and be done with
it.

> Using reg-names would be much more robust, and is quite painless to
> use. Just use platform_get_resource_by_name instead of
> platform_get_resource, and that's pretty much it.

The above argument does not really help to convince me to use
register-names, I don't really see them as useful / necessary,
adding support for them will just grow the driver-code, as well
as the devicetree bindings docs, as well as the dts files.

But if you really really want me to use register-names, just say so
and I'll modify the patch.

>
>> +- #phy-cells : from the generic phy bindings, must be 1
>> +
>> +Optional properties:
>> +- clocks : phandle + clock specifier for the phy clock
>> +- clock-names : "usb_phy"
>> +- resets : a list of phandle + reset specifier pairs
>> +- reset-names : "usb0_reset", "usb1_reset", and / or "usb2_reset"
>> +
>> +Example:
>> +	usbphy: phy at 0x01c13400 {
>> +		#phy-cells = <1>;
>> +		compatible = "allwinner,sun4i-a10-usb-phy";
>> +		/* phy base regs, phy1 pmu reg, phy2 pmu reg */
>> +		reg = <0x01c13400 0x10 0x01c14800 0x4 0x01c1c800 0x4>;
>> +		clocks = <&usb_clk 8>;
>> +		clock-names = "usb_phy";
>> +		resets = <&usb_clk 1>, <&usb_clk 2>;
>> +		reset-names = "usb1_reset", "usb2_reset";
>> +	};
>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>> index afa2354..6070c99 100644
>> --- a/drivers/phy/Kconfig
>> +++ b/drivers/phy/Kconfig
>> @@ -64,4 +64,15 @@ config BCM_KONA_USB2_PHY
>>   	help
>>   	  Enable this to support the Broadcom Kona USB 2.0 PHY.
>>
>> +config PHY_SUN4I_USB
>> +	tristate "Allwinner sunxi SoC USB PHY driver"
>> +	depends on ARCH_SUNXI
>> +	select GENERIC_PHY
>> +	help
>> +	  Enable this to support the transceiver that is part of Allwinner
>> +	  sunxi SoCs.
>> +
>> +	  This driver controls the entire USB PHY block, both the USB OTG
>> +	  parts, as well as the 2 regular USB 2 host PHYs.
>> +
>>   endmenu
>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index b57c253..9d4f8bb 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -9,3 +9,4 @@ obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)	+= phy-exynos-mipi-video.o
>>   obj-$(CONFIG_PHY_MVEBU_SATA)		+= phy-mvebu-sata.o
>>   obj-$(CONFIG_OMAP_USB2)			+= phy-omap-usb2.o
>>   obj-$(CONFIG_TWL4030_USB)		+= phy-twl4030-usb.o
>> +obj-$(CONFIG_PHY_SUN4I_USB)		+= phy-sun4i-usb.o
>> diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
>> new file mode 100644
>> index 0000000..bd9cb7fa
>> --- /dev/null
>> +++ b/drivers/phy/phy-sun4i-usb.c
>> @@ -0,0 +1,326 @@
>> +/*
>> + * Allwinner sun4i USB phy driver
>> + *
>> + * Copyright (C) 2014 Hans de Goede <[email-masked]>
>> + *
>> + * Based on code from
>> + * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
>> + *
>> + * Modelled after: Samsung S5P/EXYNOS SoC series MIPI CSIS/DSIM DPHY driver
>> + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
>> + * Author: Sylwester Nawrocki <[email-masked]>
>> + *
>> + * 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/clk.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/reset.h>
>> +
>> +#define REG_ISCR			0x00
>> +#define REG_PHYCTL			0x04
>> +#define REG_PHYBIST			0x08
>> +#define REG_PHYTUNE			0x0c
>> +
>> +#define SUNXI_AHB_ICHR8_EN		BIT(10)
>> +#define SUNXI_AHB_INCR4_BURST_EN	BIT(9)
>> +#define SUNXI_AHB_INCRX_ALIGN_EN	BIT(8)
>> +#define SUNXI_ULPI_BYPASS_EN		BIT(0)
>> +
>> +/* Common Control Bits for Both PHYs */
>> +#define PHY_PLL_BW			0x03
>> +#define PHY_RES45_CAL_EN		0x0c
>> +
>> +/* Private Control Bits for Each PHY */
>> +#define PHY_TX_AMPLITUDE_TUNE		0x20
>> +#define PHY_TX_SLEWRATE_TUNE		0x22
>> +#define PHY_VBUSVALID_TH_SEL		0x25
>> +#define PHY_PULLUP_RES_SEL		0x27
>> +#define PHY_OTG_FUNC_EN			0x28
>> +#define PHY_VBUS_DET_EN			0x29
>> +#define PHY_DISCON_TH_SEL		0x2a
>> +
>> +#define MAX_PHYS			3
>> +
>> +struct sun4i_usb_phy_data {
>> +	struct clk *clk;
>> +	void __iomem *base;
>> +	struct mutex mutex;
>> +	int num_phys;
>> +	u32 disc_thresh;
>> +	struct sun4i_usb_phy {
>> +		struct phy *phy;
>> +		void __iomem *pmu;
>> +		struct regulator *vbus;
>> +		struct reset_control *reset;
>> +		int index;
>> +	} phys[MAX_PHYS];
>> +};
>> +
>> +#define to_sun4i_usb_phy_data(phy) \
>> +	container_of((phy), struct sun4i_usb_phy_data, phys[(phy)->index])
>> +
>> +static void sun4i_usb_phy_write(struct sun4i_usb_phy *phy, u32 addr, u32 data,
>> +				int len)
>> +{
>> +	struct sun4i_usb_phy_data *phy_data = to_sun4i_usb_phy_data(phy);
>> +	u32 temp, usbc_bit = BIT(phy->index * 2);
>> +	int i;
>> +
>> +	mutex_lock(&phy_data->mutex);
>> +
>> +	for (i = 0; i < len; i++) {
>> +		temp = readl(phy_data->base + REG_PHYCTL);
>> +
>> +		/* clear the address portion */
>> +		temp &= ~(0xff << 8);
>> +
>> +		/* set the address */
>> +		temp |= ((addr + i) << 8);
>> +		writel(temp, phy_data->base + REG_PHYCTL);
>> +
>> +		/* set the data bit and clear usbc bit*/
>> +		temp = readb(phy_data->base + REG_PHYCTL);
>> +		if (data & 0x1)
>> +			temp |= BIT(7);
>> +		else
>> +			temp &= ~BIT(7);
>> +		temp &= ~usbc_bit;
>> +		writeb(temp, phy_data->base + REG_PHYCTL);
>> +
>> +		/* pulse usbc_bit */
>> +		temp = readb(phy_data->base + REG_PHYCTL);
>> +		temp |= usbc_bit;
>> +		writeb(temp, phy_data->base + REG_PHYCTL);
>> +
>> +		temp = readb(phy_data->base + REG_PHYCTL);
>> +		temp &= ~usbc_bit;
>> +		writeb(temp, phy_data->base + REG_PHYCTL);
>> +
>> +		data >>= 1;
>> +	}
>> +	mutex_unlock(&phy_data->mutex);
>> +}
>> +
>> +static void sun4i_usb_phy_passby(struct sun4i_usb_phy *phy, int enable)
>> +{
>> +	u32 bits, reg_value;
>> +
>> +	if (!phy->pmu)
>> +		return;
>> +
>> +	bits = SUNXI_AHB_ICHR8_EN | SUNXI_AHB_INCR4_BURST_EN |
>> +		SUNXI_AHB_INCRX_ALIGN_EN | SUNXI_ULPI_BYPASS_EN;
>> +
>> +	reg_value = readl(phy->pmu);
>> +
>> +	if (enable)
>> +		reg_value |= bits;
>> +	else
>> +		reg_value &= ~bits;
>> +
>> +	writel(reg_value, phy->pmu);
>> +}
>> +
>> +static int sun4i_usb_phy_init(struct phy *_phy)
>> +{
>> +	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>> +	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
>> +	int ret;
>> +
>> +	ret = clk_prepare_enable(data->clk);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = reset_control_deassert(phy->reset);
>> +	if (ret) {
>> +		clk_disable_unprepare(data->clk);
>> +		return ret;
>> +	}
>> +
>> +	/* Adjust PHY's magnitude and rate */
>> +	sun4i_usb_phy_write(phy, PHY_TX_AMPLITUDE_TUNE, 0x14, 5);
>> +
>> +	/* Disconnect threshold adjustment */
>> +	sun4i_usb_phy_write(phy, PHY_DISCON_TH_SEL, data->disc_thresh, 2);
>> +
>> +	sun4i_usb_phy_passby(phy, 1);
>> +
>> +	return 0;
>> +}
>> +
>> +static int sun4i_usb_phy_exit(struct phy *_phy)
>> +{
>> +	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>> +	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
>> +
>> +	sun4i_usb_phy_passby(phy, 0);
>> +	reset_control_assert(phy->reset);
>> +	clk_disable_unprepare(data->clk);
>> +
>> +	return 0;
>> +}
>> +
>> +static int sun4i_usb_phy_power_on(struct phy *_phy)
>> +{
>> +	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>> +	int ret = 0;
>> +
>> +	if (phy->vbus)
>> +		ret = regulator_enable(phy->vbus);
>> +
>> +	return ret;
>> +}
>> +
>> +static int sun4i_usb_phy_power_off(struct phy *_phy)
>> +{
>> +	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>> +
>> +	if (phy->vbus)
>> +		regulator_disable(phy->vbus);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct phy_ops sun4i_usb_phy_ops = {
>> +	.init		= sun4i_usb_phy_init,
>> +	.exit		= sun4i_usb_phy_exit,
>> +	.power_on	= sun4i_usb_phy_power_on,
>> +	.power_off	= sun4i_usb_phy_power_off,
>> +	.owner		= THIS_MODULE,
>> +};
>> +
>> +static struct phy *sun4i_usb_phy_xlate(struct device *dev,
>> +					struct of_phandle_args *args)
>> +{
>> +	struct sun4i_usb_phy_data *data = dev_get_drvdata(dev);
>> +
>> +	if (WARN_ON(args->args[0] == 0 || args->args[0] >= data->num_phys))
>> +		return ERR_PTR(-ENODEV);
>> +
>> +	return data->phys[args->args[0]].phy;
>> +}
>> +
>> +static int sun4i_usb_phy_probe(struct platform_device *pdev)
>> +{
>> +	struct sun4i_usb_phy_data *data;
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	void __iomem *pmu = NULL;
>> +	struct phy_provider *phy_provider;
>> +	struct reset_control *reset;
>> +	struct regulator *vbus;
>> +	struct phy *phy;
>> +	char name[16];
>> +	int i;
>> +
>> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>> +	if (!data)
>> +		return -ENOMEM;
>> +
>> +	mutex_init(&data->mutex);
>> +
>> +	if (of_device_is_compatible(np, "allwinner,sun5i-a13-usb-phy"))
>> +		data->num_phys = 2;
>> +	else
>> +		data->num_phys = 3;
>> +
>> +	if (of_device_is_compatible(np, "allwinner,sun4i-a10-usb-phy"))
>> +		data->disc_thresh = 3;
>> +	else
>> +		data->disc_thresh = 2;
>
> I'd still prefer to pass this through the .data field of of_device_id,
> but it looks much cleaner already :)

The problem with using the .data field is that I can only store a single
integer there. To store 2 I need to: define a struct, create an array
of these structs with initialization. Create an enum for indexing the
array which must be kept in sync with the initializers manually, store
either the index, or a direct pointer to the correct array entry into
the .data field, add code to get the of_device_id from the compatible
string, and then finally extract the settings from the struct again.

See IE how this is done in drivers/ata/ahci_platform.c, I've tried
to come up with a simpler way and failed, for ahci_platform.c the
struct with per compatible-string data is quite big so it makes some
sense to use this construction. Here however not so much, this adds a
whole lot of unnecessary extra code + indirection. I esp. object against
the indirection as that unnecessarily makes it harder to follow whats
going on.

>
>> +	data->clk = devm_clk_get(dev, "usb_phy");
>> +	if (IS_ERR(data->clk)) {
>> +		dev_err(dev, "could not get usb_phy clock\n");
>> +		return PTR_ERR(data->clk);
>> +	}
>> +
>> +	/* Skip 0, 0 is the phy for otg which is not yet supported. */
>> +	for (i = 1; i < data->num_phys; i++) {
>> +		snprintf(name, sizeof(name), "usb%d_vbus", i);
>> +		vbus = devm_regulator_get_optional(dev, name);
>> +		if (IS_ERR(vbus)) {
>> +			if (PTR_ERR(vbus) == -EPROBE_DEFER)
>> +				return -EPROBE_DEFER;
>> +			vbus = NULL;
>> +		}
>> +
>> +		snprintf(name, sizeof(name), "usb%d_reset", i);
>> +		reset = devm_reset_control_get(dev, name);
>> +		if (IS_ERR(phy)) {
>> +			dev_err(dev, "failed to get reset %s\n", name);
>> +			return PTR_ERR(phy);
>> +		}
>> +
>> +		if (i) { /* No pmu for usbc0 */
>> +			pmu = devm_ioremap_resource(dev,
>> +			      platform_get_resource(pdev, IORESOURCE_MEM, i));
>> +			if (IS_ERR(pmu))
>> +				return PTR_ERR(pmu);
>> +		}
>> +
>> +		phy = devm_phy_create(dev, &sun4i_usb_phy_ops, NULL);
>> +		if (IS_ERR(phy)) {
>> +			dev_err(dev, "failed to create PHY %d\n", i);
>> +			return PTR_ERR(phy);
>> +		}
>> +
>> +		data->phys[i].phy = phy;
>> +		data->phys[i].pmu = pmu;
>> +		data->phys[i].vbus = vbus;
>> +		data->phys[i].reset = reset;
>> +		data->phys[i].index = i;
>> +		phy_set_drvdata(phy, &data->phys[i]);
>> +	}
>> +
>> +	data->base = devm_ioremap_resource(dev,
>> +			platform_get_resource(pdev, IORESOURCE_MEM, 0));
>> +	if (IS_ERR(data->base))
>> +		return PTR_ERR(data->base);
>> +
>> +	dev_set_drvdata(dev, data);
>> +	phy_provider = devm_of_phy_provider_register(dev, sun4i_usb_phy_xlate);
>> +	if (IS_ERR(phy_provider))
>> +		return PTR_ERR(phy_provider);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id sun4i_usb_phy_of_match[] = {
>> +	{ .compatible = "allwinner,sun4i-a10-usb-phy" },
>> +	{ .compatible = "allwinner,sun5i-a13-usb-phy" },
>> +	{ .compatible = "allwinner,sun7i-a20-usb-phy" },
>> +	{ },
>> +};
>> +MODULE_DEVICE_TABLE(of, sun4i_usb_phy_of_match);
>> +
>> +static struct platform_driver sun4i_usb_phy_driver = {
>> +	.probe	= sun4i_usb_phy_probe,
>> +	.driver = {
>> +		.of_match_table	= sun4i_usb_phy_of_match,
>> +		.name  = "sun4i-usb-phy",
>> +		.owner = THIS_MODULE,
>> +	}
>> +};
>> +module_platform_driver(sun4i_usb_phy_driver);
>> +
>> +MODULE_DESCRIPTION("Allwinner sun4i USB phy driver");
>> +MODULE_AUTHOR("Hans de Goede <[email-masked]>");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.8.4.2
>>
>

Regards,

Hans