[PATCH 3/3] fpga: versal-fpga: Add versal fpga manager driver

Wed Jan 27 04:16:32 EST 2021

Hi

On 1/27/21 9:57 AM, Nava kishore Manne wrote:
> Hi Moritz,
> 
> 	Please find my response inline.
> 
>> -----Original Message-----
>> From: Moritz Fischer <mdf at kernel.org>
>> Sent: Sunday, January 24, 2021 5:04 AM
>> To: Nava kishore Manne <navam at xilinx.com>
>> Cc: Moritz Fischer <mdf at kernel.org>; trix at redhat.com;
>> robh+dt at kernel.org; Michal Simek <michals at xilinx.com>; linux-
>> fpga at vger.kernel.org; devicetree at vger.kernel.org; linux-arm-
>> kernel at lists.infradead.org; linux-kernel at vger.kernel.org; git
>> <git at xilinx.com>; chinnikishore369 at gmail.com; Appana Durga Kedareswara
>> Rao <appanad at xilinx.com>
>> Subject: Re: [PATCH 3/3] fpga: versal-fpga: Add versal fpga manager driver
>>
>> Hi Nava,
>>
>> On Fri, Jan 22, 2021 at 10:34:15AM +0000, Nava kishore Manne wrote:
>>> Hi Moritz,
>>>
>>> 	Thanks for the review.
>>> Please find my response inline.
>>>
>>>> -----Original Message-----
>>>> From: Moritz Fischer <mdf at kernel.org>
>>>> Sent: Tuesday, January 19, 2021 6:03 AM
>>>> To: Nava kishore Manne <navam at xilinx.com>
>>>> Cc: mdf at kernel.org; trix at redhat.com; robh+dt at kernel.org; Michal
>>>> Simek <michals at xilinx.com>; linux-fpga at vger.kernel.org;
>>>> devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
>>>> linux- kernel at vger.kernel.org; git <git at xilinx.com>;
>>>> chinnikishore369 at gmail.com; Appana Durga Kedareswara Rao
>>>> <appanad at xilinx.com>
>>>> Subject: Re: [PATCH 3/3] fpga: versal-fpga: Add versal fpga manager
>>>> driver
>>>>
>>>> Hi Nava,
>>>>
>>>> On Mon, Jan 18, 2021 at 08:13:18AM +0530, Nava kishore Manne wrote:
>>>>> This patch adds driver for versal fpga manager.
>>>> Nit: Add support for Xilinx Versal FPGA manager
>>>
>>> Will fix in v2.
>>>
>>>>>
>>>>> PDI source type can be DDR, OCM, QSPI flash etc..
>>>> No idea what PDI is :)
>>>
>>> Programmable device image (PDI).
>>> This file is generated by Xilinx Vivado tool and it contains configuration data
>> objects.
>>>
>>>>> But driver allocates memory always from DDR, Since driver supports
>>>>> only DDR source type.
>>>>>
>>>>> Signed-off-by: Appana Durga Kedareswara rao
>>>>> <appana.durga.rao at xilinx.com>
>>>>> Signed-off-by: Nava kishore Manne <nava.manne at xilinx.com>
>>>>> ---
>>>>>  drivers/fpga/Kconfig       |   8 ++
>>>>>  drivers/fpga/Makefile      |   1 +
>>>>>  drivers/fpga/versal-fpga.c | 149
>>>>> +++++++++++++++++++++++++++++++++++++
>>>>>  3 files changed, 158 insertions(+)  create mode 100644
>>>>> drivers/fpga/versal-fpga.c
>>>>>
>>>>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig index
>>>>> 5645226ca3ce..9f779c3a6739 100644
>>>>> --- a/drivers/fpga/Kconfig
>>>>> +++ b/drivers/fpga/Kconfig
>>>>> @@ -216,4 +216,12 @@ config FPGA_MGR_ZYNQMP_FPGA
>>>>>  	  to configure the programmable logic(PL) through PS
>>>>>  	  on ZynqMP SoC.
>>>>>
>>>>> +config FPGA_MGR_VERSAL_FPGA
>>>>> +        tristate "Xilinx Versal FPGA"
>>>>> +        depends on ARCH_ZYNQMP || COMPILE_TEST
>>>>> +        help
>>>>> +          Select this option to enable FPGA manager driver support for
>>>>> +          Xilinx Versal SOC. This driver uses the versal soc firmware
>>>>> +          interface to load programmable logic(PL) images
>>>>> +          on versal soc.
>>>>>  endif # FPGA
>>>>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile index
>>>>> d8e21dfc6778..40c9adb6a644 100644
>>>>> --- a/drivers/fpga/Makefile
>>>>> +++ b/drivers/fpga/Makefile
>>>>> @@ -18,6 +18,7 @@ obj-$(CONFIG_FPGA_MGR_TS73XX)		+=
>>>> ts73xx-fpga.o
>>>>>  obj-$(CONFIG_FPGA_MGR_XILINX_SPI)	+= xilinx-spi.o
>>>>>  obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
>>>>>  obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)	+= zynqmp-fpga.o
>>>>> +obj-$(CONFIG_FPGA_MGR_VERSAL_FPGA)      += versal-fpga.o
>>>>>  obj-$(CONFIG_ALTERA_PR_IP_CORE)         += altera-pr-ip-core.o
>>>>>  obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)    += altera-pr-ip-core-plat.o
>>>>>
>>>>> diff --git a/drivers/fpga/versal-fpga.c
>>>>> b/drivers/fpga/versal-fpga.c new file mode 100644 index
>>>>> 000000000000..2a42aa78b182
>>>>> --- /dev/null
>>>>> +++ b/drivers/fpga/versal-fpga.c
>>>>> @@ -0,0 +1,149 @@
>>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>>> +/*
>>>>> + * Copyright (C) 2021 Xilinx, Inc.
>>>>> + */
>>>>> +
>>>>> +#include <linux/dma-mapping.h>
>>>>> +#include <linux/fpga/fpga-mgr.h>
>>>>> +#include <linux/io.h>
>>>>> +#include <linux/kernel.h>
>>>>> +#include <linux/module.h>
>>>>> +#include <linux/of_address.h>
>>>>> +#include <linux/string.h>
>>>>> +#include <linux/firmware/xlnx-zynqmp.h>
>>>>> +
>>>>> +/* Constant Definitions */
>>>>> +#define PDI_SOURCE_TYPE	0xF
>>>>> +
>>>>> +/**
>>>>> + * struct versal_fpga_priv - Private data structure
>>>>> + * @dev:	Device data structure
>>>>> + * @flags:	flags which is used to identify the PL Image type
>>>>> + */
>>>>> +struct versal_fpga_priv {
>>>>> +	struct device *dev;
>>>>> +	u32 flags;
>>>> This seems unused ... please introduce them when/if you start using
>> them.
>>>
>>> Will fix in v2.
>>>
>>>>> +};
>>>>> +
>>>>> +static int versal_fpga_ops_write_init(struct fpga_manager *mgr,
>>>>> +				      struct fpga_image_info *info,
>>>>> +				      const char *buf, size_t size) {
>>>>> +	struct versal_fpga_priv *priv;
>>>>> +
>>>>> +	priv = mgr->priv;
>>>>> +	priv->flags = info->flags;
>>>> ? What uses this ? It seems this function could just be 'return 0' right now.
>>>
>>> Will fix in v2.
>>>
>>>>> +
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static int versal_fpga_ops_write(struct fpga_manager *mgr,
>>>>> +				 const char *buf, size_t size) {
>>>>> +	struct versal_fpga_priv *priv;
>>>>> +	dma_addr_t dma_addr = 0;
>>>>> +	char *kbuf;
>>>>> +	int ret;
>>>>> +
>>>>> +	priv = mgr->priv;
>>>>> +
>>>>> +	kbuf = dma_alloc_coherent(priv->dev, size, &dma_addr,
>>>> GFP_KERNEL);
>>>>> +	if (!kbuf)
>>>>> +		return -ENOMEM;
>>>>> +
>>>>> +	memcpy(kbuf, buf, size);
>>>>> +
>>>>> +	wmb(); /* ensure all writes are done before initiate FW call */
>>>>> +
>>>>> +	ret = zynqmp_pm_load_pdi(PDI_SOURCE_TYPE, dma_addr);
>>>>> +
>>>>> +	dma_free_coherent(priv->dev, size, kbuf, dma_addr);
>>>>> +
>>>>> +	return ret;
>>>>> +}
>>>>> +
>>>>> +static int versal_fpga_ops_write_complete(struct fpga_manager *mgr,
>>>>> +					  struct fpga_image_info *info) {
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static enum fpga_mgr_states versal_fpga_ops_state(struct
>>>>> +fpga_manager
>>>>> +*mgr) {
>>>>> +	return FPGA_MGR_STATE_OPERATING;
>>>> Is that always the case? Shouldn't that be
>> FPGA_MGR_STATE_UNKNOWN?
>>>
>>> For Versal SoC base PDI is always configured prior to Linux boot up. So I
>> make the fpga state as OPERATING.
>>> Please let know if it is not a proper implementation will think about the
>> alternate solution.
>>
>> So you're saying I can't boot a Versal SoC without a PDI / Bitstream loaded?
>> Interesting :)
>>>
> 
> For Versal SoC Vivado generated base PDI is always needed to bring-up the board. 

Look at PDI as ps7_init/psu_init file but in different format. And
bitstream is optional part of it (like a one partition).

Thanks,
Michal