[U-Boot] [RFC v2 2/2] arm64: zynqmp: spl: install a PMU firmware config object at runtime

[Mike Looijmans]

On 29-03-19 13:22, Luca Ceresoli wrote:
> Hi Michal,
> 
> thanks for the feedback.
> 
> On 27/03/19 16:03, Michal Simek wrote:
>> On 21. 03. 19 16:48, Luca Ceresoli wrote:
>>> Optionally allow U-Boot to load at the PMU firmware configuration object
>>> into the Power Management Unit (PMU) on Xilinx ZynqMP.
>>>
>>> The configuration object is required by the PMU FW to enable most SoC
>>> peripherals. So far the only way to boot using U-Boot SPL was to hard-code
>>> the configuration object in the PMU firmware. Allow a different boot
>>> process, where the PMU FW is equal for any ZynqMP chip and its
>>> configuration is passed at runtime by U-Boot SPL.
>>>
>>> All the code for Inter-processor communication with the PMU is isolated in
>>> a new file (pmu_ipc.c). The code is inspired by the same feature as
>>> implemented in the Xilinx First Stage Bootloader (FSBL) and Arm Trusted
>>> Firmware:
>>>
>>>   * https://github.com/Xilinx/embeddedsw/blob/fb647e6b4c00f5154eba52a88b948195b6f1dc2b/lib/sw_apps/zynqmp_fsbl/src/xfsbl_misc_drivers.c#L295
>>>   * https://github.com/ARM-software/arm-trusted-firmware/blob/c48d02bade88b07fa7f43aa44e5217f68e5d047f/plat/xilinx/zynqmp/pm_service/pm_api_sys.c#L357
>>>
>>> The load is logged on the console during boot:
>>>
>>>    U-Boot SPL 2018.01 (Mar 20 2019 - 08:12:21)
>>>    Loading PMUFW cfg obj (2008 bytes)
>>>    EL Level:	EL3
>>>    ...
>>>
>>> Signed-off-by: Luca Ceresoli <luca at lucaceresoli.net>
> [...]
>>> diff --git a/board/xilinx/zynqmp/pmu_ipc.c b/board/xilinx/zynqmp/pmu_ipc.c
>>> new file mode 100644
>>> index 000000000000..6306d33d6f17
>>> --- /dev/null
>>> +++ b/board/xilinx/zynqmp/pmu_ipc.c
>>> @@ -0,0 +1,116 @@
>>> +// SPDX-License-Identifier: GPL-2.0+
>>> +/*
>>> + * Inter-Processor Communication with the Platform Management Unit (PMU)
>>> + * firmware.
> [...]
>>> +static int pmu_ipc_request(const u32 *req, size_t req_len,
>>> +			   u32 *res, size_t res_maxlen)
>>> +{
>>> +	u32 status;
>>> +
>>> +	if (req_len > PMUFW_PAYLOAD_ARG_CNT ||
>>> +	    res_maxlen > PMUFW_PAYLOAD_ARG_CNT)
>>> +		return -EINVAL;
>>> +
>>> +	pmu_ipc_send_request(req, req_len);
>>> +
>>> +	/* Raise Inter-Processor Interrupt to PMU and wait for response */
>>> +	writel(IPI_BIT_MASK_PMU0, IPI_REG_BASE_APU + IPI_REG_OFFSET_TRIG);
>>> +	do {
>>> +		status = readl(IPI_REG_BASE_APU + IPI_REG_OFFSET_OBR);
>>> +	} while (status & IPI_BIT_MASK_PMU0);
>>> +
>>> +	pmu_ipc_read_response(res, res_maxlen);
>>> +
>>> +	return 0;
>>> +}
>>
>> All above should be mailbox driver. It means this should go to
>> drivers/mailbox and be split to mbox send/recv functions.
> 
> Oh, wow, there's a mailbox uclass! I'll have a look into it.
> 
>> But I have no problem to use this configuration in the first patch and
>> move to mbox driver in separate patch.
> 
> Good to know, I'll use this option in case it takes too long to make it
> a proper mailbox driver.
> 
>>> +/**
>>> + * Send a configuration object to the PMU firmware.
>>> + *
>>> + * @cfg_obj Pointer to the configuration object
>>> + * @size    Size of @cfg_obj in bytes
>>> + */
>>> +void zynqmp_pmufw_load_config_object(const void *cfg_obj, size_t size)
>>> +{
>>> +	const u32 *ocm = (u32 *)CONFIG_SPL_TEXT_BASE;
>>> +	const u32 request[] = {
>>> +		PMUFW_CMD_SET_CONFIGURATION,
>>> +		CONFIG_SPL_TEXT_BASE
>>> +	};
>>> +	u32 response;
>>> +	int err;
>>> +
>>> +	printf("Loading PMUFW cfg obj (%ld bytes)\n", size);
>>> +
>>> +	memcpy(ocm, cfg_obj, size);
>>> +
>>> +	err = pmu_ipc_request(request,  ARRAY_SIZE(request), &response, 1);
>>> +	if (err)
>>> +		panic("Cannot load PMUFW configuration object (%d)\n", err);
>>> +	if (response != 0)
>>> +		panic("PMUFW returned 0x%08x status!\n", response);
>>> +}
>>
>> And this can stay here or go to arch/arm/mach-zynq/
> 
> Ok, I'll move it to arch/arm/mach-zynq/pmu.c or so.
> 
> I assume "zynq" here means the whole zynq family, including zynqmp.
> 
>>> diff --git a/board/xilinx/zynqmp/pmu_ipc.h b/board/xilinx/zynqmp/pmu_ipc.h
>>> new file mode 100644
>>> index 000000000000..37bb72c1b20a
>>> --- /dev/null
>>> +++ b/board/xilinx/zynqmp/pmu_ipc.h
>>> @@ -0,0 +1,14 @@
>>> +/* SPDX-License-Identifier: GPL-2.0+ */
>>> +/*
>>> + * (C) Copyright 2019 Luca Ceresoli
>>> + * Luca Ceresoli <luca at lucaceresoli.net>
>>> + */
>>> +
>>> +#ifndef __ZYNQMP_PMU_IPC_H__
>>> +#define __ZYNQMP_PMU_IPC_H__
>>> +
>>> +#include <linux/types.h>
>>> +
>>> +void zynqmp_pmufw_load_config_object(const void *cfg_obj, size_t size);
>>> +
>>
>>
>> arch/arm/mach-zynqmp/include/mach/sys_proto.h should be fine.
> 
> Ok, but I guess you mean s/zynqmp/zynq/, as above.
> 
>>> +#endif /* __ZYNQMP_PMU_IPC_H__ */
>>> diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
>>> index 5e1d2116bc32..1d5e25961863 100644
>>> --- a/board/xilinx/zynqmp/zynqmp.c
>>> +++ b/board/xilinx/zynqmp/zynqmp.c
>>> @@ -4,6 +4,8 @@
>>>    * Michal Simek <michal.simek at xilinx.com>
>>>    */
>>>   
>>> +#include "pmu_ipc.h"
>>> +
>>>   #include <common.h>
>>>   #include <sata.h>
>>>   #include <ahci.h>
>>> @@ -302,6 +304,10 @@ static char *zynqmp_get_silicon_idcode_name(void)
>>>   }
>>>   #endif
>>>   
>>> +#ifdef ZYNQMP_LOAD_PM_CFG_OBJ
>>> +#include CONFIG_ZYNQMP_LOAD_PM_CFG_OBJ_FILE
>>> +#endif
>>> +
>>>   int board_early_init_f(void)
>>>   {
>>>   	int ret = 0;
>>> @@ -332,6 +338,11 @@ int board_early_init_f(void)
>>>   
>>>   int board_init(void)
>>>   {
>>> +#if defined(CONFIG_SPL_BUILD) && defined(ZYNQMP_LOAD_PM_CFG_OBJ)
>>> +	zynqmp_pmufw_load_config_object(XPm_ConfigObject,
>>> +					sizeof(XPm_ConfigObject));
>>> +#endif
>>
>> As we discussed over IRC. I think that this should be simply bin
>> firmware file compare to C built by u-boot.
> 
> Sure. I have a working prototype that uses a binary blob. It still needs
> a decent way to produce a blob and to be updated according to your review.

It should be doable to write a Python script to parse the C file and create an 
equivalent binary (using "struct" module) which is just an array of integers 
in the end. That avoids the need for a microblaze C compiler...