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Message-ID: <3859c748-01f0-4dbd-05d6-20fff31edf11@amlogic.com>
Date: Thu, 26 Sep 2019 17:17:05 +0800
From: Jianxin Pan <jianxin.pan@...ogic.com>
To: Kevin Hilman <khilman@...libre.com>,
<linux-amlogic@...ts.infradead.org>
CC: Zhiqiang Liang <zhiqiang.liang@...ogic.com>,
Rob Herring <robh+dt@...nel.org>,
Neil Armstrong <narmstrong@...libre.com>,
Jerome Brunet <jbrunet@...libre.com>,
Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
<linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<devicetree@...r.kernel.org>, Jian Hu <jian.hu@...ogic.com>,
Hanjie Lin <hanjie.lin@...ogic.com>,
Victor Wan <victor.wan@...ogic.com>,
Xingyu Chen <xingyu.chen@...ogic.com>
Subject: Re: [PATCH 2/3] soc: amlogic: Add support for Secure power domains
controller
Hi Kevin,
Thanks for your review. Please see my comments below.
On 2019/9/26 6:41, Kevin Hilman wrote:
> Hi Jianxin,
>
> Jianxin Pan <jianxin.pan@...ogic.com> writes:
>
>> Add support for the Amlogic Secure Power controller. In A1/C1 series, power
>> control registers are in secure domain, and should be accessed by smc.
>>
>> Signed-off-by: Jianxin Pan <jianxin.pan@...ogic.com>
>> Signed-off-by: Zhiqiang Liang <zhiqiang.liang@...ogic.com>
>
> Thanks for the new power domain driver.
>
>> ---
>> drivers/soc/amlogic/Kconfig | 13 +++
>> drivers/soc/amlogic/Makefile | 1 +
>> drivers/soc/amlogic/meson-secure-pwrc.c | 182 ++++++++++++++++++++++++++++++++
>> 3 files changed, 196 insertions(+)
>> create mode 100644 drivers/soc/amlogic/meson-secure-pwrc.c
>>
>> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
>> index bc2c912..6cb06e7 100644
>> --- a/drivers/soc/amlogic/Kconfig
>> +++ b/drivers/soc/amlogic/Kconfig
>> @@ -48,6 +48,19 @@ config MESON_EE_PM_DOMAINS
>> Say yes to expose Amlogic Meson Everything-Else Power Domains as
>> Generic Power Domains.
>>
>> +config MESON_SECURE_PM_DOMAINS
>> + bool "Amlogic Meson Secure Power Domains driver"
>> + depends on ARCH_MESON || COMPILE_TEST
>> + depends on PM && OF
>> + depends on HAVE_ARM_SMCCC
>> + default ARCH_MESON
>> + select PM_GENERIC_DOMAINS
>> + select PM_GENERIC_DOMAINS_OF
>> + help
>> + Support for the power controller on Amlogic A1/C1 series.
>> + Say yes to expose Amlogic Meson Secure Power Domains as Generic
>> + Power Domains.
>> +
>> config MESON_MX_SOCINFO
>> bool "Amlogic Meson MX SoC Information driver"
>> depends on ARCH_MESON || COMPILE_TEST
>> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
>> index de79d044..7b8c5d3 100644
>> --- a/drivers/soc/amlogic/Makefile
>> +++ b/drivers/soc/amlogic/Makefile
>> @@ -5,3 +5,4 @@ obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
>> obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
>> obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
>> obj-$(CONFIG_MESON_EE_PM_DOMAINS) += meson-ee-pwrc.o
>> +obj-$(CONFIG_MESON_SECURE_PM_DOMAINS) += meson-secure-pwrc.o
>> diff --git a/drivers/soc/amlogic/meson-secure-pwrc.c b/drivers/soc/amlogic/meson-secure-pwrc.c
>> new file mode 100644
>> index 00000000..00c7232
>> --- /dev/null
>> +++ b/drivers/soc/amlogic/meson-secure-pwrc.c
>> @@ -0,0 +1,182 @@
>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
[...]
>> +
>> +static bool pwrc_secure_get_power(struct meson_secure_pwrc_domain *pwrc_domain)
>> +{
>> + struct arm_smccc_res res;
>> +
>> + arm_smccc_smc(SMC_PWRC_GET, pwrc_domain->index, 0,
>> + 0, 0, 0, 0, 0, &res);
>> +
>> + return res.a0 & 0x1;
>
> Please use a #define with a readable name for this mask.
> The return type of this smc is bool. I will remove 0x1 mask in next version.
Another question about smc:
In this driver, no share memory is needed, and I use arm_smccc_smc() directly.
Should I add secure-monitor = <&sm> in dtb and use meson_sm_call() from sm driver instead?
>> +}
>
> What does the return value for this function mean? Does true mean
> "powered off" or "powered on">
The return vaule for SMC_PWRC_GET :
0 -> power on
1 -> power off> See the rename I just did on the ee-pwrc driver:
> https://lore.kernel.org/linux-amlogic/20190925213528.21515-2-khilman@kernel.org/
> I will follow and rename to _is_off() in the next verson.
>> +static int meson_secure_pwrc_off(struct generic_pm_domain *domain)
>> +{
>> + struct arm_smccc_res res;
>> + struct meson_secure_pwrc_domain *pwrc_domain =
[...]
>> +
>> +#define SEC_PD(__name, __flag) \
>> +{ \
>> + .name = #__name, \
>> + .index = PWRC_##__name##_ID, \
>> + .get_power = pwrc_secure_get_power, \
>> + .flags = __flag, \
>> +}
>> +
>> +static struct meson_secure_pwrc_domain_desc a1_pwrc_domains[] = {
>> + SEC_PD(DSPA, 0),
>> + SEC_PD(DSPB, 0),
>> + SEC_PD(UART, GENPD_FLAG_ALWAYS_ON),
>
> This flag should only be used for domains where there are no linux
> drivers.
>
> Rather than using this flag, you need to add a 'power-domain' property
> to the uart driver in DT, and then update the meson_uart driver to use
> the runtime PM API so that the domain is enabled whenever the UART is in
> use.
PM_UART Power domain is shared by uart, msr, jtag and cec.
Uart should keep working in BL31, after kernel suspend and before kernel resume.
>
>> + SEC_PD(DMC, GENPD_FLAG_ALWAYS_ON),
>
> Please explain the need for ALWAYS_ON.
>
PM_DMC is used for DDR PHY ana/dig and DMC.
There is no linux drver for them, and it should be always on.
I will add comments for all these always on domains.
>> + SEC_PD(I2C, 0),
>> + SEC_PD(PSRAM, 0),
>> + SEC_PD(ACODEC, 0),
>> + SEC_PD(AUDIO, 0),
>> + SEC_PD(OTP, 0),
>> + SEC_PD(DMA, 0),
>> + SEC_PD(SD_EMMC, 0),
>> + SEC_PD(RAMA, 0),
>> + SEC_PD(RAMB, GENPD_FLAG_ALWAYS_ON),
>
> Please explain the need for ALWAYS_ON.
>
In A1, SRAMB is used for bl31 ATF.
>> + SEC_PD(IR, 0),
>> + SEC_PD(SPICC, 0),
>> + SEC_PD(SPIFC, 0),
>> + SEC_PD(USB, 0),
>> + SEC_PD(NIC, GENPD_FLAG_ALWAYS_ON),
>
> Please explain the need for ALWAYS_ON.
>
PD_NIC is used for NIC400, and should keep on.
>> + SEC_PD(PDMIN, 0),
>> + SEC_PD(RSA, 0),
>> +};
>> +
>> +static int meson_secure_pwrc_probe(struct platform_device *pdev)
>> +{
>> + const struct meson_secure_pwrc_domain_data *match;
>> + struct meson_secure_pwrc *pwrc;
>> + int i;
[...]
>> +
>> + return of_genpd_add_provider_onecell(pdev->dev.of_node, &pwrc->xlate);
>> +}
>> +
>> +static struct meson_secure_pwrc_domain_data meson_secure_a1_pwrc_data = {
>> + .domains = a1_pwrc_domains,
>> + .count = ARRAY_SIZE(a1_pwrc_domains),
>> +};
>> +
>> +static const struct of_device_id meson_secure_pwrc_match_table[] = {
>> + {
>> + .compatible = "amlogic,meson-a1-pwrc",
>> + .data = &meson_secure_a1_pwrc_data,
>> + },
>> + { }
>
> as mentioned by Martin, please add the sentinel string here. Helps for
> readability.
>
OK, I will fix it. Thank you.
>> +};
>> +
>> +static struct platform_driver meson_secure_pwrc_driver = {
>> + .probe = meson_secure_pwrc_probe,
>> + .driver = {
>> + .name = "meson_secure_pwrc",
>> + .of_match_table = meson_secure_pwrc_match_table,
>> + },
>> +};
>> +
>> +static int meson_secure_pwrc_init(void)
>> +{
>> + return platform_driver_register(&meson_secure_pwrc_driver);
>> +}
>> +arch_initcall_sync(meson_secure_pwrc_init);
>
> Please use builtin_platform_driver() or explain in detail why the
> initcall is needed.
>
OK, I will use builtin_platform_driver instead.
> Thanks,
>
> Kevin
>
> .
>
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