[U-Boot] [PATCH v2 05/13] drivers: usb: common: add support to get maximum speed from dt

[Vignesh R]

On Tuesday 13 June 2017 07:31 PM, Marek Vasut wrote:
> On 06/13/2017 02:10 PM, Vignesh R wrote:
>> From: Mugunthan V N <mugunthanvnm at ti.com>
>>
>> Add support to get maximum speed from dt so that usb drivers
>> makes use of it for DT parsing.
>>
>> Signed-off-by: Mugunthan V N <mugunthanvnm at ti.com>
>> Signed-off-by: Vignesh R <vigneshr at ti.com>
>> Reviewed-by: Simon Glass <sjg at chromium.org>
>> ---
>>  drivers/usb/common/common.c | 29 +++++++++++++++++++++++++++++
>>  include/linux/usb/otg.h     |  9 +++++++++
>>  scripts/Makefile.spl        |  1 +
>>  3 files changed, 39 insertions(+)
>>
>> diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
>> index 35c2dc18d955..c11689dc36fa 100644
>> --- a/drivers/usb/common/common.c
>> +++ b/drivers/usb/common/common.c
>> @@ -10,6 +10,7 @@
>>  #include <common.h>
>>  #include <libfdt.h>
>>  #include <linux/usb/otg.h>
>> +#include <linux/usb/ch9.h>
>>  
>>  DECLARE_GLOBAL_DATA_PTR;
>>  
>> @@ -38,3 +39,31 @@ enum usb_dr_mode usb_get_dr_mode(int node)
>>  
>>  	return USB_DR_MODE_UNKNOWN;
>>  }
>> +
>> +static const char *const speed_names[] = {
>> +	[USB_SPEED_UNKNOWN] = "UNKNOWN",
>> +	[USB_SPEED_LOW] = "low-speed",
>> +	[USB_SPEED_FULL] = "full-speed",
>> +	[USB_SPEED_HIGH] = "high-speed",
>> +	[USB_SPEED_WIRELESS] = "wireless",
>> +	[USB_SPEED_SUPER] = "super-speed",
>> +};
>> +
>> +enum usb_device_speed usb_get_maximum_speed(int node)
>> +{
>> +	const void *fdt = gd->fdt_blob;
>> +	const char *max_speed;
>> +	int i;
>> +
>> +	max_speed = fdt_getprop(fdt, node, "maximum-speed", NULL);
>> +	if (!max_speed) {
>> +		error("usb dr_mode not found\n");
> 
> Really dr_mode ?

Sorry, will fix this.

> 
>> +		return USB_DR_MODE_UNKNOWN;
>> +	}
>> +
>> +	for (i = 0; i < ARRAY_SIZE(speed_names); i++)
>> +		if (!strcmp(max_speed, speed_names[i]))
>> +			return i;
> 
> Shouldn't this somehow take into account the controller capabilities if
> the maximum-speed node is missing ?

Idea was, this is just a helper function and will return
USB_SPEED_UNKNOWN when "maximum-speed" property is missing. The
particular USB controller driver (like dwc3) can take decision of
falling back to default capabilities.
I will leave this as is, but will update patch 6/13 to fall back to
default capability when USB_DR_MODE_UNKNOWN is returned.

> 
>> +	return USB_SPEED_UNKNOWN;
>> +}
>> diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
>> index 8f8ac6aeefe3..b61ef19b22f3 100644
>> --- a/include/linux/usb/otg.h
>> +++ b/include/linux/usb/otg.h
>> @@ -26,4 +26,13 @@ enum usb_dr_mode {
>>   */
>>  enum usb_dr_mode usb_get_dr_mode(int node);
>>  
>> +/**
>> + * usb_get_maximum_speed() - Get maximum speed for given device
>> + * @node: Node offset to the given device
>> + *
>> + * The function gets phy interface string from property 'maximum-speed',
>> + * and returns the correspondig enum usb_device_speed
>> + */
>> +enum usb_device_speed usb_get_maximum_speed(int node);
>> +
>>  #endif /* __LINUX_USB_OTG_H */
>> diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
>> index ac3c2c7f1342..bffea085b329 100644
>> --- a/scripts/Makefile.spl
>> +++ b/scripts/Makefile.spl
>> @@ -78,6 +78,7 @@ endif
>>  
>>  libs-$(CONFIG_SPL_LIBDISK_SUPPORT) += disk/
>>  libs-y += drivers/
>> +libs-y += drivers/usb/common/
> 
> This looks weird, drivers/ is already included so why this explicit path
> addition ?

Makefile under drivers/ neither includes usb/ directory nor does usb/
directory has a Makefile. Hence, above entry is needed.
I guess, this is how it is for SPL build.

> 
>>  libs-$(CONFIG_SPL_USB_GADGET_SUPPORT) += drivers/usb/dwc3/
>>  libs-y += dts/
>>  libs-y += fs/
>>
> 
> 

-- 
Regards
Vignesh