Re: [PATCHv3] phy: mapphone-mdm6600: Add USB PHY driver for MDM6600 on Droid 4

[Kishon Vijay Abraham I]

Hi Tony,

On Wednesday 07 March 2018 08:26 PM, Tony Lindgren wrote:
> Let's add support for the GPIO controlled USB PHY on the MDM6600 modem.
> It is used on some Motorola Mapphone series of phones and tablets such
> as Droid 4.
> 
> The MDM6600 is hardwired to the first OHCI port in the Droid 4 case, and
> is controlled by several GPIOs. The USB PHY is integrated into the MDM6600
> device it seems. We know this as we get L3 errors from omap-usb-host if
> trying to use the PHY before MDM6600 is configured.
> 
> The GPIOs controlling MDM6600 are used to power device on and off, to
> configure the USB start-up mode (normal mode versus USB flashing), and
> they also tell the state of the MDM6600 device.
> 
> The two start-up mode GPIOs are dual-purposed and used for out of band
> (OOB) wake-up for USB and TS 27.010 serial mux. But we need to configure
> the USB start-up mode first to get MDM6600 booted in the right mode to
> be usable in the first place.
> 
> Note that the Motorola Mapphone Linux kernel tree has a "radio-ctrl"
> driver for modems. But it really does not control the radio at all, it
> just controls the modem power and start-up mode for USB. So I came to
> the conclusion that we're better off having this done in the USB PHY
> driver. For adding support for USB flashing mode, we can later on add
> a kernel module option for flash_mode=1 or something similar.
> 
> Also note that currently there is no PM runtime support for the OHCI
> on omap variant SoCs. So for low(er) power idle states, currenty both
> ohci-platform and phy-mapphone-mdm6600 must be unloaded or unbound.
> 
> For reference here is what I measured for total power consumption on
> an idle Droid 4 with and without USB related MDM6600 modules:
> 
> idle lcd off	phy-mapphone-mdm6600	ohci-platform
> 153mW		284mW			344mW
> 
> So it seems that MDM6600 is currently not yet idling even with it's
> radio turned off, but that's something that is beyond the control of
> this USB PHY driver. This patch does get us to the point where modem
> data and GPS are usable with libqmi and ModemManager for example.
> Voice calls need more audio driver work.
> 
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Marcel Partap <mpartap@xxxxxxx>
> Cc: Michael Scott <michael.scott@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> 
> Changes since v2:
> - Dropped OTG as suggested by Kishon
> - Added Rob's Reviewed-by
> 
> Changes since v1:
> - Fixed up issues noticed by Rob and Sebastian
> - Implemented wake irq handler (for debug use only for now)
> - Improved error handling based on more testing
> 
> ---
>  .../bindings/phy/phy-mapphone-mdm6600.txt          |  30 ++
>  drivers/phy/motorola/Kconfig                       |   9 +
>  drivers/phy/motorola/Makefile                      |   1 +
>  drivers/phy/motorola/phy-mapphone-mdm6600.c        | 549 +++++++++++++++++++++
>  4 files changed, 589 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/phy-mapphone-mdm6600.txt
>  create mode 100644 drivers/phy/motorola/phy-mapphone-mdm6600.c
> 
> diff --git a/Documentation/devicetree/bindings/phy/phy-mapphone-mdm6600.txt b/Documentation/devicetree/bindings/phy/phy-mapphone-mdm6600.txt
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/phy-mapphone-mdm6600.txt
> @@ -0,0 +1,30 @@
> +Device tree binding documentation for Motorola Mapphone MDM6600 USB PHY
> +
> +Required properties:
> +- compatible		Must be "motorola,mapphone-mdm6600"
> +- enable-gpios		GPIO to enable the USB PHY
> +- power-gpios		GPIO to power on the device
> +- reset-gpios		GPIO to reset the device
> +- motorola,mode-gpios	Two GPIOs to configure MDM6600 USB start-up mode for
> +			normal mode versus USB flashing mode
> +- motorola,cmd-gpios	Three GPIOs to control the power state of the MDM6600
> +- motorola,status-gpios	Three GPIOs to read the power state of the MDM6600
> +
> +Example:
> +
> +usb-phy {
> +	compatible = "motorola,mapphone-mdm6600";
> +	enable-gpios = <&gpio3 31 GPIO_ACTIVE_LOW>;
> +	power-gpios = <&gpio2 22 GPIO_ACTIVE_HIGH>;
> +	reset-gpios = <&gpio2 17 GPIO_ACTIVE_HIGH>;
> +	motorola,mode-gpios = <&gpio5 20 GPIO_ACTIVE_HIGH>,
> +			      <&gpio5 21 GPIO_ACTIVE_HIGH>;
> +	motorola,cmd-gpios = <&gpio4 7 GPIO_ACTIVE_HIGH>,
> +			     <&gpio4 8 GPIO_ACTIVE_HIGH>,
> +			     <&gpio5 14 GPIO_ACTIVE_HIGH>;
> +	motorola,status-gpios = <&gpio2 20 GPIO_ACTIVE_HIGH>,
> +				<&gpio2 21 GPIO_ACTIVE_HIGH>,
> +				<&gpio2 23 GPIO_ACTIVE_HIGH>;
> +	#phy-cells = <0>;
> +};
> +
> diff --git a/drivers/phy/motorola/Kconfig b/drivers/phy/motorola/Kconfig
> --- a/drivers/phy/motorola/Kconfig
> +++ b/drivers/phy/motorola/Kconfig
> @@ -10,3 +10,12 @@ config PHY_CPCAP_USB
>  	help
>  	  Enable this for USB to work on Motorola phones and tablets
>  	  such as Droid 4.
> +
> +config PHY_MAPPHONE_MDM6600
> +	tristate "Motorola Mapphone MDM6600 modem USB PHY driver"
> +	depends on OF && USB_SUPPORT
> +	select GENERIC_PHY
> +	select USB_PHY

given that OTG is removed, USB_PHY won't be required anymore. Sorry for not
stating this explicitly before.
> +	help
> +	  Enable this for MDM6600 USB modem to work on Motorola phones
> +	  and tablets such as Droid 4.
> diff --git a/drivers/phy/motorola/Makefile b/drivers/phy/motorola/Makefile
> --- a/drivers/phy/motorola/Makefile
> +++ b/drivers/phy/motorola/Makefile
> @@ -3,3 +3,4 @@
>  #
>  
>  obj-$(CONFIG_PHY_CPCAP_USB)		+= phy-cpcap-usb.o
> +obj-$(CONFIG_PHY_MAPPHONE_MDM6600)	+= phy-mapphone-mdm6600.o
> diff --git a/drivers/phy/motorola/phy-mapphone-mdm6600.c b/drivers/phy/motorola/phy-mapphone-mdm6600.c
> new file mode 100644
> --- /dev/null
> +++ b/drivers/phy/motorola/phy-mapphone-mdm6600.c
> @@ -0,0 +1,549 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Motorola Mapphone MDM6600 modem GPIO controlled USB PHY driver
> + * Copyright (C) 2018 Tony Lindgren <tony@xxxxxxxxxxx>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/of_platform.h>
> +#include <linux/phy/phy.h>
> +#include <linux/usb/phy_companion.h>

phy_companion is unused below.
> +
> +#define PHY_MDM6600_PHY_DELAY_MS	4000	/* PHY enable 2.2s to 3.5s */
> +#define PHY_MDM6600_ENABLED_DELAY_MS	8000	/* 8s more total for MDM6600 */
> +
> +enum phy_mdm6600_ctrl_lines {
> +	PHY_MDM6600_ENABLE,			/* USB PHY enable */
> +	PHY_MDM6600_POWER,			/* Device power */
> +	PHY_MDM6600_RESET,			/* Device reset */
> +	PHY_MDM6600_NR_CTRL_LINES,
> +};
> +
> +enum phy_mdm6600_bootmode_lines {
> +	PHY_MDM6600_MODE0,			/* out USB mode0 and OOB wake */
> +	PHY_MDM6600_MODE1,			/* out USB mode1, in OOB wake */
> +	PHY_MDM6600_NR_MODE_LINES,
> +};
> +
> +enum phy_mdm6600_cmd_lines {
> +	PHY_MDM6600_CMD0,
> +	PHY_MDM6600_CMD1,
> +	PHY_MDM6600_CMD2,
> +	PHY_MDM6600_NR_CMD_LINES,
> +};
> +
> +enum phy_mdm6600_status_lines {
> +	PHY_MDM6600_STATUS0,
> +	PHY_MDM6600_STATUS1,
> +	PHY_MDM6600_STATUS2,
> +	PHY_MDM6600_NR_STATUS_LINES,
> +};
> +
> +/*
> + * MDM6600 command codes. These are based on Motorola Mapphone Linux
> + * kernel tree.
> + */
> +enum phy_mdm6600_cmd {
> +	PHY_MDM6600_CMD_BP_PANIC_ACK,
> +	PHY_MDM6600_CMD_DATA_ONLY_BYPASS,	/* Reroute USB to CPCAP PHY */
> +	PHY_MDM6600_CMD_FULL_BYPASS,		/* Reroute USB to CPCAP PHY */
> +	PHY_MDM6600_CMD_NO_BYPASS,		/* Request normal USB mode */
> +	PHY_MDM6600_CMD_BP_SHUTDOWN_REQ,	/* Request device power off */
> +	PHY_MDM6600_CMD_BP_UNKNOWN_5,
> +	PHY_MDM6600_CMD_BP_UNKNOWN_6,
> +	PHY_MDM6600_CMD_UNDEFINED,
> +};
> +
> +/*
> + * MDM6600 status codes. These are based on Motorola Mapphone Linux
> + * kernel tree.
> + */
> +enum phy_mdm6600_status {
> +	PHY_MDM6600_STATUS_PANIC,		/* Seems to be really off */
> +	PHY_MDM6600_STATUS_PANIC_BUSY_WAIT,
> +	PHY_MDM6600_STATUS_QC_DLOAD,
> +	PHY_MDM6600_STATUS_RAM_DOWNLOADER,	/* MDM6600 USB flashing mode */
> +	PHY_MDM6600_STATUS_PHONE_CODE_AWAKE,	/* MDM6600 normal USB mode */
> +	PHY_MDM6600_STATUS_PHONE_CODE_ASLEEP,
> +	PHY_MDM6600_STATUS_SHUTDOWN_ACK,
> +	PHY_MDM6600_STATUS_UNDEFINED,
> +};
> +
> +static const char * const
> +phy_mdm6600_status_name[] = {
> +	"off", "busy", "qc_dl", "ram_dl", "awake",
> +	"asleep", "shutdown", "undefined",
> +};
> +
> +struct phy_mdm6600 {
> +	struct device *dev;
> +	struct usb_phy phy;

usb_phy can be removed.
> +	struct phy *generic_phy;
> +	struct phy_provider *phy_provider;
> +	struct gpio_desc *ctrl_gpios[PHY_MDM6600_NR_CTRL_LINES];
> +	struct gpio_descs *mode_gpios;
> +	struct gpio_descs *status_gpios;
> +	struct gpio_descs *cmd_gpios;
> +	struct delayed_work bootup_work;
> +	struct delayed_work status_work;
> +	struct completion ack;
> +	bool enabled;				/* mdm6600 phy enabled */
> +	bool running;				/* mdm6600 boot done */
> +	int status;
> +};
> +
> +static int phy_mdm6600_init(struct phy *x)
> +{
> +	struct phy_mdm6600 *ddata = phy_get_drvdata(x);
> +	struct gpio_desc *enable_gpio = ddata->ctrl_gpios[PHY_MDM6600_ENABLE];
> +
> +	if (!ddata->enabled)
> +		return -EPROBE_DEFER;
> +
> +	gpiod_set_value_cansleep(enable_gpio, 0);
> +
> +	return 0;
> +}
> +
> +static int phy_mdm6600_power_on(struct phy *x)
> +{
> +	struct phy_mdm6600 *ddata = phy_get_drvdata(x);
> +	struct gpio_desc *enable_gpio = ddata->ctrl_gpios[PHY_MDM6600_ENABLE];
> +
> +	if (!ddata->enabled)
> +		return -ENODEV;
> +
> +	gpiod_set_value_cansleep(enable_gpio, 1);
> +
> +	return 0;
> +}
> +
> +static int phy_mdm6600_power_off(struct phy *x)
> +{
> +	struct phy_mdm6600 *ddata = phy_get_drvdata(x);
> +	struct gpio_desc *enable_gpio = ddata->ctrl_gpios[PHY_MDM6600_ENABLE];
> +
> +	if (!ddata->enabled)
> +		return -ENODEV;
> +
> +	gpiod_set_value_cansleep(enable_gpio, 0);
> +
> +	return 0;
> +}
> +
> +static const struct phy_ops gpio_usb_ops = {
> +	.init = phy_mdm6600_init,
> +	.power_on = phy_mdm6600_power_on,
> +	.power_off = phy_mdm6600_power_off,
> +	.owner = THIS_MODULE,
> +};
> +
> +/**
> + * phy_mdm6600_cmd() - send a command request to mdm6600
> + * @ddata: device driver data
> + *
> + * Configures the three command request GPIOs to the specified value.
> + */
> +static void phy_mdm6600_cmd(struct phy_mdm6600 *ddata, int val)
> +{
> +	int values[PHY_MDM6600_NR_CMD_LINES];
> +	int i;
> +
> +	val &= (1 << PHY_MDM6600_NR_CMD_LINES) - 1;
> +	for (i = 0; i < PHY_MDM6600_NR_CMD_LINES; i++)
> +		values[i] = (val & BIT(i)) >> i;
> +
> +	gpiod_set_array_value_cansleep(PHY_MDM6600_NR_CMD_LINES,
> +				       ddata->cmd_gpios->desc, values);
> +}
> +
> +/**
> + * phy_mdm6600_status() - read mdm6600 status lines
> + * @ddata: device driver data
> + */
> +static void phy_mdm6600_status(struct work_struct *work)
> +{
> +	struct phy_mdm6600 *ddata;
> +	struct device *dev;
> +	int values[PHY_MDM6600_NR_STATUS_LINES];
> +	int error, i, val = 0;
> +
> +	ddata = container_of(work, struct phy_mdm6600, status_work.work);
> +	dev = ddata->dev;
> +
> +	error = gpiod_get_array_value_cansleep(PHY_MDM6600_NR_CMD_LINES,
> +					       ddata->status_gpios->desc,
> +					       values);
> +	if (error)
> +		return;
> +
> +	for (i = 0; i < PHY_MDM6600_NR_CMD_LINES; i++) {
> +		val |= values[i] << i;
> +		dev_dbg(ddata->dev, "XXX %s: i: %i values[i]: %i val: %i\n",
> +			__func__, i, values[i], val);
> +	}
> +	ddata->status = val;
> +
> +	dev_info(dev, "modem status: %i %s\n",
> +		 ddata->status,
> +		 phy_mdm6600_status_name[ddata->status & 7]);
> +	complete(&ddata->ack);
> +}
> +
> +static irqreturn_t phy_mdm6600_irq_thread(int irq, void *data)
> +{
> +	struct phy_mdm6600 *ddata = data;
> +
> +	schedule_delayed_work(&ddata->status_work, msecs_to_jiffies(10));
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/**
> + * phy_mdm6600_wakeirq_thread - handle mode1 line OOB wake after booting
> + * @irq: interrupt
> + * @data: interrupt handler data
> + *
> + * GPIO mode1 is used initially as output to configure the USB boot
> + * mode for mdm6600. After booting it is used as input for OOB wake
> + * signal from mdm6600 to the SoC. Just use it for debug info only
> + * for now.
> + */
> +static irqreturn_t phy_mdm6600_wakeirq_thread(int irq, void *data)
> +{
> +	struct phy_mdm6600 *ddata = data;
> +	struct gpio_desc *mode_gpio1;
> +
> +	mode_gpio1 = ddata->mode_gpios->desc[PHY_MDM6600_MODE1];
> +	dev_dbg(ddata->dev, "OOB wake on mode_gpio1: %i\n",
> +		gpiod_get_value(mode_gpio1));
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/**
> + * phy_mdm6600_init_irq() - initialize mdm6600 status IRQ lines
> + * @ddata: device driver data
> + */
> +static void phy_mdm6600_init_irq(struct phy_mdm6600 *ddata)
> +{
> +	struct device *dev = ddata->dev;
> +	int i, error, irq;
> +
> +	for (i = PHY_MDM6600_STATUS0;
> +	     i <= PHY_MDM6600_STATUS2; i++) {
> +		struct gpio_desc *gpio = ddata->status_gpios->desc[i];
> +
> +		irq = gpiod_to_irq(gpio);
> +		if (irq <= 0)
> +			continue;
> +
> +		error = devm_request_threaded_irq(dev, irq, NULL,
> +					phy_mdm6600_irq_thread,
> +					IRQF_TRIGGER_RISING |
> +					IRQF_TRIGGER_FALLING |
> +					IRQF_ONESHOT,
> +					"mdm6600",
> +					ddata);
> +		if (error)
> +			dev_warn(dev, "no modem status irq%i: %i\n",
> +				 irq, error);
> +	}
> +}
> +
> +struct phy_mdm6600_map {
> +	const char *name;
> +	int direction;
> +};
> +
> +static const struct phy_mdm6600_map
> +phy_mdm6600_ctrl_gpio_map[PHY_MDM6600_NR_CTRL_LINES] = {
> +	{ "enable", GPIOD_OUT_LOW, },		/* low = phy disabled */
> +	{ "power", GPIOD_OUT_LOW, },		/* low = off */
> +	{ "reset", GPIOD_OUT_HIGH, },		/* high = reset */
> +};
> +
> +/**
> + * phy_mdm6600_init_lines() - initialize mdm6600 GPIO lines
> + * @ddata: device driver data
> + */
> +static int phy_mdm6600_init_lines(struct phy_mdm6600 *ddata)
> +{
> +	struct device *dev = ddata->dev;
> +	int i;
> +
> +	/* MDM6600 control lines */
> +	for (i = 0; i < ARRAY_SIZE(phy_mdm6600_ctrl_gpio_map); i++) {
> +		const struct phy_mdm6600_map *map =
> +			&phy_mdm6600_ctrl_gpio_map[i];
> +		struct gpio_desc **gpio = &ddata->ctrl_gpios[i];
> +
> +		*gpio = devm_gpiod_get(dev, map->name, map->direction);
> +		if (IS_ERR(*gpio)) {
> +			dev_info(dev, "gpio %s error %li\n",
> +				 map->name, PTR_ERR(*gpio));
> +			return PTR_ERR(*gpio);
> +		}
> +	}
> +
> +	/* MDM6600 USB start-up mode output lines */
> +	ddata->mode_gpios = devm_gpiod_get_array(dev, "motorola,mode",
> +						 GPIOD_OUT_LOW);
> +	if (IS_ERR(ddata->mode_gpios))
> +		return PTR_ERR(ddata->mode_gpios);
> +
> +	if (ddata->mode_gpios->ndescs != PHY_MDM6600_NR_MODE_LINES)
> +		return -EINVAL;
> +
> +	/* MDM6600 status input lines */
> +	ddata->status_gpios = devm_gpiod_get_array(dev, "motorola,status",
> +						   GPIOD_IN);
> +	if (IS_ERR(ddata->status_gpios))
> +		return PTR_ERR(ddata->status_gpios);
> +
> +	if (ddata->status_gpios->ndescs != PHY_MDM6600_NR_STATUS_LINES)
> +		return -EINVAL;
> +
> +	/* MDM6600 cmd output lines */
> +	ddata->cmd_gpios = devm_gpiod_get_array(dev, "motorola,cmd",
> +						GPIOD_OUT_LOW);
> +	if (IS_ERR(ddata->cmd_gpios))
> +		return PTR_ERR(ddata->cmd_gpios);
> +
> +	if (ddata->cmd_gpios->ndescs != PHY_MDM6600_NR_CMD_LINES)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +/**
> + * phy_mdm6600_device_power_on() - power on mdm6600 device
> + * @ddata: device driver data
> + *
> + * To get the integrated USB phy in MDM6600 takes some hoops. We must ensure
> + * the shared USB bootmode GPIOs are configured, then request modem start-up,
> + * reset and power-up.. And then we need to recycle the shared USB bootmode
> + * GPIOs as they are also used for Out of Band (OOB) wake for the USB and
> + * TS 27.010 serial mux.
> + */
> +static int phy_mdm6600_device_power_on(struct phy_mdm6600 *ddata)
> +{
> +	struct gpio_desc *mode_gpio0, *mode_gpio1, *reset_gpio, *power_gpio;
> +	int error = 0, wakeirq;
> +
> +	mode_gpio0 = ddata->mode_gpios->desc[PHY_MDM6600_MODE0];
> +	mode_gpio1 = ddata->mode_gpios->desc[PHY_MDM6600_MODE1];
> +	reset_gpio = ddata->ctrl_gpios[PHY_MDM6600_RESET];
> +	power_gpio = ddata->ctrl_gpios[PHY_MDM6600_POWER];
> +
> +	/*
> +	 * Shared GPIOs must be low for normal USB mode. After booting
> +	 * they are used for OOB wake signaling. These can be also used
> +	 * to configure USB flashing mode later on based on a module
> +	 * parameter.
> +	 */
> +	gpiod_set_value_cansleep(mode_gpio0, 0);
> +	gpiod_set_value_cansleep(mode_gpio1, 0);
> +
> +	/* Request start-up mode */
> +	phy_mdm6600_cmd(ddata, PHY_MDM6600_CMD_NO_BYPASS);
> +
> +	/* Request a reset first */
> +	gpiod_set_value_cansleep(reset_gpio, 0);
> +	msleep(100);
> +
> +	/* Toggle power GPIO to request mdm6600 to start */
> +	gpiod_set_value_cansleep(power_gpio, 1);
> +	msleep(100);
> +	gpiod_set_value_cansleep(power_gpio, 0);
> +
> +	/*
> +	 * Looks like the USB PHY needs between 2.2 to 4 seconds.
> +	 * If we try to use it before that, we will get L3 errors
> +	 * from omap-usb-host trying to access the PHY. See also
> +	 * phy_mdm6600_init() for -EPROBE_DEFER.
> +	 */
> +	msleep(PHY_MDM6600_PHY_DELAY_MS);
> +	ddata->enabled = true;
> +
> +	/* Booting up the rest of MDM6600 will take total about 8 seconds */
> +	dev_info(ddata->dev, "Waiting for power up request to complete..\n");
> +	if (wait_for_completion_timeout(&ddata->ack,
> +			msecs_to_jiffies(PHY_MDM6600_ENABLED_DELAY_MS))) {
> +		if (ddata->status > PHY_MDM6600_STATUS_PANIC &&
> +		    ddata->status < PHY_MDM6600_STATUS_SHUTDOWN_ACK)
> +			dev_info(ddata->dev, "Powered up OK\n");
> +	} else {
> +		ddata->enabled = false;
> +		error = -ETIMEDOUT;
> +		dev_err(ddata->dev, "Timed out powering up\n");
> +	}
> +
> +	/* Reconfigure mode1 GPIO as input for OOB wake */
> +	gpiod_direction_input(mode_gpio1);
> +
> +	wakeirq = gpiod_to_irq(mode_gpio1);
> +	if (wakeirq <= 0)
> +		return wakeirq;
> +
> +	error = devm_request_threaded_irq(ddata->dev, wakeirq, NULL,
> +					  phy_mdm6600_wakeirq_thread,
> +					  IRQF_TRIGGER_RISING |
> +					  IRQF_TRIGGER_FALLING |
> +					  IRQF_ONESHOT,
> +					  "mdm6600-wake",
> +					  ddata);
> +	if (error)
> +		dev_warn(ddata->dev, "no modem wakeirq irq%i: %i\n",
> +			 wakeirq, error);
> +
> +	ddata->running = true;
> +
> +	return error;
> +}
> +
> +/**
> + * phy_mdm6600_device_power_off() - power off mdm6600 device
> + * @ddata: device driver data
> + */
> +static void phy_mdm6600_device_power_off(struct phy_mdm6600 *ddata)
> +{
> +	struct gpio_desc *reset_gpio =
> +		ddata->ctrl_gpios[PHY_MDM6600_RESET];
> +
> +	ddata->enabled = false;
> +	phy_mdm6600_cmd(ddata, PHY_MDM6600_CMD_BP_SHUTDOWN_REQ);
> +	msleep(100);
> +
> +	gpiod_set_value_cansleep(reset_gpio, 1);
> +
> +	dev_info(ddata->dev, "Waiting for power down request to complete.. ");
> +	if (wait_for_completion_timeout(&ddata->ack,
> +					msecs_to_jiffies(5000))) {
> +		if (ddata->status == PHY_MDM6600_STATUS_PANIC)
> +			dev_info(ddata->dev, "Powered down OK\n");
> +	} else {
> +		dev_err(ddata->dev, "Timed out powering down\n");
> +	}
> +}
> +
> +static void phy_mdm6600_deferred_power_on(struct work_struct *work)
> +{
> +	struct phy_mdm6600 *ddata;
> +	int error;
> +
> +	ddata = container_of(work, struct phy_mdm6600, bootup_work.work);
> +
> +	error = phy_mdm6600_device_power_on(ddata);
> +	if (error)
> +		dev_err(ddata->dev, "Device not functional\n");
> +}
> +
> +static const struct of_device_id phy_mdm6600_id_table[] = {
> +	{ .compatible = "motorola,mapphone-mdm6600", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, phy_mdm6600_id_table);
> +
> +static int phy_mdm6600_probe(struct platform_device *pdev)
> +{
> +	struct phy_mdm6600 *ddata;
> +	int error;
> +
> +	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
> +	if (!ddata)
> +		return -ENOMEM;
> +
> +	INIT_DELAYED_WORK(&ddata->bootup_work,
> +			  phy_mdm6600_deferred_power_on);
> +	INIT_DELAYED_WORK(&ddata->status_work, phy_mdm6600_status);
> +	init_completion(&ddata->ack);
> +
> +	ddata->dev = &pdev->dev;
> +	ddata->phy.dev = ddata->dev;
> +	ddata->phy.label = "phy_mdm6600";
> +	ddata->phy.type = USB_PHY_TYPE_USB2;

All of this can be removed since usb_phy is not required.
> +
> +	platform_set_drvdata(pdev, ddata);
> +
> +	error = phy_mdm6600_init_lines(ddata);
> +	if (error)
> +		return error;
> +
> +	phy_mdm6600_init_irq(ddata);
> +
> +	ddata->generic_phy = devm_phy_create(ddata->dev, NULL, &gpio_usb_ops);
> +	if (IS_ERR(ddata->generic_phy)) {
> +		error = PTR_ERR(ddata->generic_phy);
> +		goto cleanup;
> +	}
> +
> +	phy_set_drvdata(ddata->generic_phy, ddata);
> +
> +	ddata->phy_provider =
> +		devm_of_phy_provider_register(ddata->dev,
> +					      of_phy_simple_xlate);
> +	if (IS_ERR(ddata->phy_provider)) {
> +		error = PTR_ERR(ddata->phy_provider);
> +		goto cleanup;
> +	}
> +
> +	schedule_delayed_work(&ddata->bootup_work, 0);
> +
> +	/*
> +	 * See phy_mdm6600_device_power_on(). We should be able
> +	 * to remove this eventually when ohci-platform can deal
> +	 * with -EPROBE_DEFER.
> +	 */
> +	msleep(PHY_MDM6600_PHY_DELAY_MS + 500);
> +
> +	usb_add_phy_dev(&ddata->phy);

This should also be removed.

Thanks
Kishon