Re: [PATCH] usb: imx: implement support for limiting host to full speed

[Sascha Hauer <sha@pengutronix.de>]

On Fri, Jun 22, 2018 at 07:46:57PM +0300, Nikita Yushchenko wrote:
> This is needed when host is known to not work properly in high speed
> mode.
> 
> In linux, chipidea driver supports 'maximum-speed' device tree property.
> When that is set to "full-speed", driver sets PFSC bit in PORTSC
> register, which disallows use of high speed mode.
> 
> This patch implements same support for barebox.
> 
> Important technical detail is that PFSC bit is cleared by port reset,
> thus setting it has to be done in ehci->init() callback which is called
> after ehci_reset().
> 
> Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
> ---

Applied, thanks

Sascha

>  drivers/usb/core/common.c      | 12 ++++++++++++
>  drivers/usb/core/of.c          | 24 ++++++++++++++++++++++++
>  drivers/usb/imx/chipidea-imx.c | 13 +++++++++++++
>  include/usb/ch9.h              |  6 ++++++
>  include/usb/chipidea-imx.h     |  1 +
>  include/usb/usb.h              |  3 +++
>  6 files changed, 59 insertions(+)
> 
> diff --git a/drivers/usb/core/common.c b/drivers/usb/core/common.c
> index 690d5a39e..bcbe3a155 100644
> --- a/drivers/usb/core/common.c
> +++ b/drivers/usb/core/common.c
> @@ -17,3 +17,15 @@ const char *usb_speed_string(enum usb_device_speed speed)
>  	return speed_names[speed];
>  }
>  EXPORT_SYMBOL_GPL(usb_speed_string);
> +
> +enum usb_device_speed usb_speed_by_string(const char *string)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(speed_names); i++)
> +		if (!strcmp(string, speed_names[i]))
> +			return i;
> +
> +	return USB_SPEED_UNKNOWN;
> +}
> +EXPORT_SYMBOL_GPL(usb_speed_by_string);
> diff --git a/drivers/usb/core/of.c b/drivers/usb/core/of.c
> index fd2036842..979088ef4 100644
> --- a/drivers/usb/core/of.c
> +++ b/drivers/usb/core/of.c
> @@ -90,3 +90,27 @@ enum usb_phy_interface of_usb_get_phy_mode(struct device_node *np,
>  	return USBPHY_INTERFACE_MODE_UNKNOWN;
>  }
>  EXPORT_SYMBOL_GPL(of_usb_get_phy_mode);
> +
> +/**
> + * of_usb_get_maximum_speed - Get maximum speed for given device_node
> + * @np:	Pointer to the given device_node
> + *
> + * The function gets maximum speed string from property 'maximum-speed',
> + * and returns the correspondig enum usb_device_speed
> + */
> +enum usb_device_speed of_usb_get_maximum_speed(struct device_node *np,
> +		const char *propname)
> +{
> +	const char *maximum_speed;
> +	int err;
> +
> +	if (!propname)
> +		propname = "maximum-speed";
> +
> +	err = of_property_read_string(np, propname, &maximum_speed);
> +	if (err < 0)
> +		return USB_SPEED_UNKNOWN;
> +
> +	return usb_speed_by_string(maximum_speed);
> +}
> +EXPORT_SYMBOL_GPL(of_usb_get_maximum_speed);
> diff --git a/drivers/usb/imx/chipidea-imx.c b/drivers/usb/imx/chipidea-imx.c
> index 505f5eb35..3e3e6a365 100644
> --- a/drivers/usb/imx/chipidea-imx.c
> +++ b/drivers/usb/imx/chipidea-imx.c
> @@ -51,6 +51,7 @@ struct imx_chipidea {
>  static int imx_chipidea_port_init(void *drvdata)
>  {
>  	struct imx_chipidea *ci = drvdata;
> +	uint32_t portsc;
>  	int ret;
>  
>  	if ((ci->flags & MXC_EHCI_PORTSC_MASK) == MXC_EHCI_MODE_ULPI) {
> @@ -74,6 +75,14 @@ static int imx_chipidea_port_init(void *drvdata)
>  	if (ret)
>  		dev_err(ci->dev, "misc init failed: %s\n", strerror(-ret));
>  
> +	/* PFSC bit is reset by ehci_reset(), thus have to set it not in
> +	 * probe but here, after ehci_reset() is already called */
> +	if (ci->flags & MXC_EHCI_PFSC) {
> +		portsc = readl(ci->base + 0x184);
> +		portsc |= MXC_EHCI_PFSC;
> +		writel(portsc, ci->base + 0x184);
> +	}
> +
>  	return ret;
>  }
>  
> @@ -159,6 +168,10 @@ static int imx_chipidea_probe_dt(struct imx_chipidea *ci)
>  				   "over-current-active-high", NULL))
>  		ci->flags |= MXC_EHCI_OC_PIN_ACTIVE_LOW;
>  
> +	if (of_usb_get_maximum_speed(ci->dev->device_node, NULL) ==
> +			USB_SPEED_FULL)
> +		ci->flags |= MXC_EHCI_PFSC;
> +
>  	return 0;
>  }
>  
> diff --git a/include/usb/ch9.h b/include/usb/ch9.h
> index ab5d53192..b44d41e85 100644
> --- a/include/usb/ch9.h
> +++ b/include/usb/ch9.h
> @@ -1004,6 +1004,12 @@ struct usb_set_sel_req {
>   */
>  const char *usb_speed_string(enum usb_device_speed speed);
>  
> +/**
> + * usb_speed_by_string() - Get speed from human readable name.
> + * @string: The human readable name for the speed. If it is not one of known
> + *   names, USB_SPEED_UNKNOWN will be returned.
> + */
> +enum usb_device_speed usb_speed_by_string(const char *string);
>  
>  /**
>   * usb_state_string - Returns human readable name for the state.
> diff --git a/include/usb/chipidea-imx.h b/include/usb/chipidea-imx.h
> index 640ae0694..973aee6a0 100644
> --- a/include/usb/chipidea-imx.h
> +++ b/include/usb/chipidea-imx.h
> @@ -13,6 +13,7 @@
>  #define MXC_EHCI_MODE_ULPI		(2 << 30)
>  #define MXC_EHCI_MODE_HSIC		(1 << 25)
>  #define MXC_EHCI_MODE_SERIAL		(3 << 30)
> +#define MXC_EHCI_PFSC			(1 << 24)
>  
>  /*
>   * USB misc flags
> diff --git a/include/usb/usb.h b/include/usb/usb.h
> index 93308cec0..9aab06c87 100644
> --- a/include/usb/usb.h
> +++ b/include/usb/usb.h
> @@ -438,6 +438,9 @@ enum usb_dr_mode {
>  enum usb_phy_interface of_usb_get_phy_mode(struct device_node *np,
>  		const char *propname);
>  
> +enum usb_device_speed of_usb_get_maximum_speed(struct device_node *np,
> +		const char *propname);
> +
>  extern struct list_head usb_device_list;
>  
>  #endif /*_USB_H_ */
> -- 
> 2.11.0
> 
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox