[PATCH 2/6] usb: add devicetree helpers for determining dr_mode and phy_type

Peter Chen peter.chen at freescale.com
Wed Jan 30 21:30:36 EST 2013


On Wed, Jan 30, 2013 at 04:29:38PM +0100, Sascha Hauer wrote:
> From: Michael Grzeschik <m.grzeschik at pengutronix.de>
> 
> This adds two little devicetree helper functions for determining the
> dr_mode (host, peripheral, otg) and phy_type (utmi, ulpi,...) from
> the devicetree.
> 
> Signed-off-by: Michael Grzeschik <m.grzeschik at pengutronix.de>
> Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
>  drivers/usb/usb-common.c |   69 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/usb/of.h   |   27 ++++++++++++++++++
>  include/linux/usb/otg.h  |    7 +++++
>  include/linux/usb/phy.h  |    9 ++++++
>  4 files changed, 112 insertions(+)
>  create mode 100644 include/linux/usb/of.h
> 
> diff --git a/drivers/usb/usb-common.c b/drivers/usb/usb-common.c
> index d29503e..1c0292c 100644
> --- a/drivers/usb/usb-common.c
> +++ b/drivers/usb/usb-common.c
> @@ -14,6 +14,9 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/usb/ch9.h>
> +#include <linux/of.h>
> +#include <linux/usb/of.h>
> +#include <linux/usb/otg.h>
>  
>  const char *usb_speed_string(enum usb_device_speed speed)
>  {
> @@ -32,4 +35,70 @@ const char *usb_speed_string(enum usb_device_speed speed)
>  }
>  EXPORT_SYMBOL_GPL(usb_speed_string);
>  
> +#ifdef CONFIG_OF
> +static const char *usb_dr_modes[] = {
> +	[USB_DR_MODE_UNKNOWN]		= "",
> +	[USB_DR_MODE_HOST]		= "host",
> +	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
> +	[USB_DR_MODE_OTG]		= "otg",
> +};
> +
> +/**
> + * of_usb_get_dr_mode - Get dual role mode for given device_node
> + * @np:	Pointer to the given device_node
> + *
> + * The function gets phy interface string from property 'dr_mode',
> + * and returns the correspondig enum usb_phy_dr_mode
> + */
> +enum usb_phy_dr_mode of_usb_get_dr_mode(struct device_node *np)
The word "phy" at usb_phy_dr_mode may cause misunderstand, just usb_dr_mode
is ok
> +{
> +	const char *dr_mode;
> +	int err, i;
> +
> +	err = of_property_read_string(np, "dr_mode", &dr_mode);
> +	if (err < 0)
> +		return USB_DR_MODE_UNKNOWN;
> +
> +	for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
> +		if (!strcasecmp(dr_mode, usb_dr_modes[i]))
> +			return i;
Just curious, why not using strcmp?
> +
> +	return USB_DR_MODE_UNKNOWN;
> +}
> +
> +#ifdef CONFIG_OF
> +enum usb_phy_interface of_usb_get_phy_mode(struct device_node *np);
> +enum usb_phy_dr_mode of_usb_get_dr_mode(struct device_node *np);
> +#else
> +static inline enum usb_phy_interface of_usb_get_phy_mode(struct device_node *np)
> +{
> +	return USBPHY_INTERFACE_MODE_NA;
> +}
> +
> +static inline enum usb_phy_dr_mode of_usb_get_dr_mode(struct device_node *np)
> +{
> +	return USB_DR_MODE_UNKNOWN;
> +}
For, dr_mode, if value has not existed, you use *_UNKNOWN, why
for usbphy,  you use *_NA. It is better uniform.

-- 

Best Regards,
Peter Chen




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