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

[Luca Ceresoli]

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.

-- 
Luca