[U-Boot] [PATCH 11/11] imx: mx7d: isolate resources to domain 0 for A7 core

[Peng Fan <van.freenix@gmail.com>]

Hi Stefan,
On Wed, Jan 06, 2016 at 11:04:44PM -0800, Stefan Agner wrote:
>On 2016-01-04 21:56, Peng Fan wrote:
>> From: Peng Fan <peng.fan@nxp.com>
>> 
>> In current design, if any peripheral was assigned to both A7 and M4,
>> it will receive ipg_stop or ipg_wait when any of the 2 platforms
>> enter low power mode. We will have a risk that, if A7 enter wait,
>> M4 enter stop, peripheral will have chance to get ipg_stop and ipg_wait
>> asserted same time. Also if M4 enters stop mode, A7 will have no
>> chance to access the peripheral.
>> There are 26 peripherals impacted by this IC issue:
>
>s/impacted/affected

Will fix in V2.

>
>
>> SIM2(sim2/emvsim2)
>> SIM1(sim1/emvsim1)
>> UART1/UART2/UART3/UART4/UART5/UART6/UART7
>> SAI1/SAI2/SAI3
>> WDOG1/WDOG2/WDOG3/WDOG4
>> GPT1/GPT2/GPT3/GPT4
>> PWM1/PWM2/PWM3/PWM4
>> ENET1/ENET2
>> Software Workaround:
>> The solution is set M4 to a different domain with A core.
>
>Set the M4 core to a different domain using A core? Or merely the
>peripherals?

peripherals. Thanks pointing this.

>
>> So the peripherals are not shared by them. This way requires
>> the uboot implemented the RDC driver and set the 26 IPs above
>> to domain 0 only. M4 image will set the M4 to domain 1 and
>> set peripheral which it will use to domain 1.
>
>Hm, what happens if the M4 image is not doing that? Would that causing
>problems?

If M4 A7 and all the peripherals are in one domain, if A7 runs into low
power idle or other low mode, it will send out ipg_stop/wait signal,
and m4 will not be able to access the peripherals. So need to
assign peripherals to different domains for M4 and A7.

Thanks,
Peng.

>
>--
>Stefan
>
>> 
>> This patch enables the CONFIG_IMX_RDC and CONFIG_IMX_BOOTAUX for
>> i.MX7D SABRESD board, and setup the 26 IP resources to domain 0.
>> 
>> Signed-off-by: Ye.Li <ye.li@nxp.com>
>> Signed-off-by: Peng Fan <peng.fan@nxp.com>
>> ---
>>  arch/arm/cpu/armv7/mx7/soc.c  | 64 +++++++++++++++++++++++++++++++++++++++++++
>>  configs/mx7dsabresd_defconfig |  2 ++
>>  2 files changed, 66 insertions(+)
>> 
>> diff --git a/arch/arm/cpu/armv7/mx7/soc.c b/arch/arm/cpu/armv7/mx7/soc.c
>> index 2121ff2..ede7d53 100644
>> --- a/arch/arm/cpu/armv7/mx7/soc.c
>> +++ b/arch/arm/cpu/armv7/mx7/soc.c
>> @@ -12,6 +12,8 @@
>>  #include <asm/imx-common/boot_mode.h>
>>  #include <asm/imx-common/dma.h>
>>  #include <asm/imx-common/hab.h>
>> +#include <asm/imx-common/rdc-sema.h>
>> +#include <asm/arch/imx-rdc.h>
>>  #include <asm/arch/crm_regs.h>
>>  #include <dm.h>
>>  #include <imx_thermal.h>
>> @@ -29,6 +31,65 @@ U_BOOT_DEVICE(imx7_thermal) = {
>>  };
>>  #endif
>>  
>> +#ifdef CONFIG_IMX_RDC
>> +/*
>> + * In current design, if any peripheral was assigned to both A7 and M4,
>> + * it will receive ipg_stop or ipg_wait when any of the 2 platforms enter
>> + * low power mode. So M4 sleep will cause some peripherals fail to work
>> + * at A7 core side. At default, all resources are in domain 0 - 3.
>> + *
>> + * There are 26 peripherals impacted by this IC issue:
>> + * SIM2(sim2/emvsim2)
>> + * SIM1(sim1/emvsim1)
>> + * UART1/UART2/UART3/UART4/UART5/UART6/UART7
>> + * SAI1/SAI2/SAI3
>> + * WDOG1/WDOG2/WDOG3/WDOG4
>> + * GPT1/GPT2/GPT3/GPT4
>> + * PWM1/PWM2/PWM3/PWM4
>> + * ENET1/ENET2
>> + * Software Workaround:
>> + * Here we setup some resources to domain 0 where M4 codes will move
>> + * the M4 out of this domain. Then M4 is not able to access them any longer.
>> + * This is a workaround for ic issue. So the peripherals are not shared
>> + * by them. This way requires the uboot implemented the RDC driver and
>> + * set the 26 IPs above to domain 0 only. M4 code will assign resource
>> + * to its own domain, if it want to use the resource.
>> + */
>> +static rdc_peri_cfg_t const resources[] = {
>> +	(RDC_PER_SIM1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_SIM2 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART2 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART3 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART4 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART5 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART6 | RDC_DOMAIN(0)),
>> +	(RDC_PER_UART7 | RDC_DOMAIN(0)),
>> +	(RDC_PER_SAI1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_SAI2 | RDC_DOMAIN(0)),
>> +	(RDC_PER_SAI3 | RDC_DOMAIN(0)),
>> +	(RDC_PER_WDOG1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_WDOG2 | RDC_DOMAIN(0)),
>> +	(RDC_PER_WDOG3 | RDC_DOMAIN(0)),
>> +	(RDC_PER_WDOG4 | RDC_DOMAIN(0)),
>> +	(RDC_PER_GPT1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_GPT2 | RDC_DOMAIN(0)),
>> +	(RDC_PER_GPT3 | RDC_DOMAIN(0)),
>> +	(RDC_PER_GPT4 | RDC_DOMAIN(0)),
>> +	(RDC_PER_PWM1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_PWM2 | RDC_DOMAIN(0)),
>> +	(RDC_PER_PWM3 | RDC_DOMAIN(0)),
>> +	(RDC_PER_PWM4 | RDC_DOMAIN(0)),
>> +	(RDC_PER_ENET1 | RDC_DOMAIN(0)),
>> +	(RDC_PER_ENET2 | RDC_DOMAIN(0)),
>> +};
>> +
>> +static void isolate_resource(void)
>> +{
>> +	imx_rdc_setup_peripherals(resources, ARRAY_SIZE(resources));
>> +}
>> +#endif
>> +
>>  #if defined(CONFIG_SECURE_BOOT)
>>  struct imx_sec_config_fuse_t const imx_sec_config_fuse = {
>>  	.bank = 1,
>> @@ -163,6 +224,9 @@ int arch_cpu_init(void)
>>  	mxs_dma_init();
>>  #endif
>>  
>> +	if (IS_ENABLED(CONFIG_IMX_RDC))
>> +		isolate_resource();
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/configs/mx7dsabresd_defconfig b/configs/mx7dsabresd_defconfig
>> index 420d13e..1d262c1 100644
>> --- a/configs/mx7dsabresd_defconfig
>> +++ b/configs/mx7dsabresd_defconfig
>> @@ -1,6 +1,8 @@
>>  CONFIG_ARM=y
>>  CONFIG_ARCH_MX7=y
>>  CONFIG_TARGET_MX7DSABRESD=y
>> +CONFIG_IMX_RDC=y
>> +CONFIG_IMX_BOOTAUX=y
>>
>> CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/mx7dsabresd/imximage.cfg,MX7D"
>>  # CONFIG_CMD_BOOTD is not set
>>  # CONFIG_CMD_IMI is not set