[U-Boot] [PATCH v1 5/7] spl: add serial download protocol (SDP) support

[Stefan Agner]

On 2017-08-08 03:43, Lothar Waßmann wrote:
> Hi,
> 
> On Fri,  4 Aug 2017 16:38:11 -0700 Stefan Agner wrote:
>> From: Stefan Agner <stefan.agner at toradex.com>
>>
>> Add USB serial download protocol support to SPL. If the SoC started
>> in recovery mode the SPL will immediately switch to SDP and wait for
>> further downloads/commands from the host side.
>>
>> Signed-off-by: Stefan Agner <stefan.agner at toradex.com>
>> ---
>>
>>  common/spl/Kconfig          |  6 ++++++
>>  common/spl/Makefile         |  1 +
>>  common/spl/spl_sdp.c        | 38 ++++++++++++++++++++++++++++++++++++++
>>  drivers/usb/gadget/Makefile |  1 +
>>  4 files changed, 46 insertions(+)
>>  create mode 100644 common/spl/spl_sdp.c
>>
>> diff --git a/common/spl/Kconfig b/common/spl/Kconfig
>> index 4de81392b0..95378b98a0 100644
>> --- a/common/spl/Kconfig
>> +++ b/common/spl/Kconfig
>> @@ -646,6 +646,12 @@ config SPL_DFU_RAM
>>
>>  endchoice
>>
>> +config SPL_USB_SDP_SUPPORT
>> +	bool "Support SDP (Serial Download Protocol)"
>> +	help
>> +	  Enable Serial Download Protocol (SDP) device support in SPL. This
>> +	  allows to download images into memory and execute (jump to) them
>> +	  using the same protocol as implemented by the i.MX family's boot ROM.
>>  endif
>>
>>  config SPL_WATCHDOG_SUPPORT
>> diff --git a/common/spl/Makefile b/common/spl/Makefile
>> index 47a64dd7d0..a979560acf 100644
>> --- a/common/spl/Makefile
>> +++ b/common/spl/Makefile
>> @@ -29,4 +29,5 @@ obj-$(CONFIG_SPL_SATA_SUPPORT) += spl_sata.o
>>  obj-$(CONFIG_SPL_DFU_SUPPORT) += spl_dfu.o
>>  obj-$(CONFIG_SPL_SPI_LOAD) += spl_spi.o
>>  obj-$(CONFIG_SPL_RAM_SUPPORT) += spl_ram.o
>> +obj-$(CONFIG_SPL_USB_SDP_SUPPORT) += spl_sdp.o
>>  endif
>> diff --git a/common/spl/spl_sdp.c b/common/spl/spl_sdp.c
>> new file mode 100644
>> index 0000000000..faa74b8bec
>> --- /dev/null
>> +++ b/common/spl/spl_sdp.c
>> @@ -0,0 +1,38 @@
>> +/*
>> + * (C) Copyright 2016 Toradex
>> + * Author: Stefan Agner <stefan.agner at toradex.com>
>> + *
>> + * SPDX-License-Identifier:	GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <spl.h>
>> +#include <usb.h>
>> +#include <g_dnl.h>
>> +#include <sdp.h>
>> +
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>> +static int spl_sdp_load_image(struct spl_image_info *spl_image,
>> +			      struct spl_boot_device *bootdev)
>> +{
>> +	int ret;
>> +
>> +	g_dnl_clear_detach();
>> +	g_dnl_register("usb_dnl_sdp");
>> +
>> +	ret = sdp_init();
>> +	if (ret) {
>> +		error("SDP init failed: %d", ret);
>> +		return -ENODEV;
>> +	}
>> +
>> +	ret = sdp_handle();
>>
> This function (and sdp_init() above) always return 0. Do you expect to
> be changed in future? Otherwise the return type of those functions
> should be changed to void.
> 

I followed f_thor's approach here which use int in both functions, but
yeah, in the SDP case there is currently no error condition.

Not sure there will be one added in the future, I guess we could just
make it void for now.

--
Stefan