Re: [PATCH v2 03/12] ARM: exynos: Re-introduce Exynos4212 support

From: Henrik Grimler
Date: Wed Apr 19 2023 - 16:25:48 EST

Hi Artur,

On Sun, Apr 16, 2023 at 03:34:13PM +0200, Artur Weber wrote:
> The platform was originally dropped in commit bca9085e0ae9 ("ARM:
> dts: exynos: remove Exynos4212 support (dead code)"), as there were
> no boards using it.
>
> We will be adding a device that uses it, so add it back.
>
> This effectively reverts commit 9e43eca3c874 ("ARM: EXYNOS: Remove
> Exynos4212 related dead code").
>
> Signed-off-by: Artur Weber <aweber.kernel@xxxxxxxxx>
> ---
> arch/arm/mach-exynos/Kconfig | 5 +++++
> arch/arm/mach-exynos/common.h | 8 ++++++++
> arch/arm/mach-exynos/exynos.c | 2 ++
> arch/arm/mach-exynos/firmware.c | 8 +++++++-
> arch/arm/mach-exynos/pm.c | 2 +-
> arch/arm/mach-exynos/suspend.c | 4 ++++
> 6 files changed, 27 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
> index 4d3b40e4049a..b3d5df5225fe 100644
> --- a/arch/arm/mach-exynos/Kconfig
> +++ b/arch/arm/mach-exynos/Kconfig
> @@ -78,6 +78,11 @@ config CPU_EXYNOS4210
> default y
> depends on ARCH_EXYNOS4
>
> +config SOC_EXYNOS4212
> + bool "Samsung Exynos4212"
> + default y
> + depends on ARCH_EXYNOS4
> +
> config SOC_EXYNOS4412
> bool "Samsung Exynos4412"
> default y
> diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
> index 29eb075b24a4..c9e85d33c309 100644
> --- a/arch/arm/mach-exynos/common.h
> +++ b/arch/arm/mach-exynos/common.h
> @@ -15,6 +15,7 @@
> #define EXYNOS3_SOC_MASK 0xFFFFF000
>
> #define EXYNOS4210_CPU_ID 0x43210000
> +#define EXYNOS4212_CPU_ID 0x43220000
> #define EXYNOS4412_CPU_ID 0xE4412200
> #define EXYNOS4_CPU_MASK 0xFFFE0000
>
> @@ -34,6 +35,7 @@ static inline int is_samsung_##name(void) \
>
> IS_SAMSUNG_CPU(exynos3250, EXYNOS3250_SOC_ID, EXYNOS3_SOC_MASK)
> IS_SAMSUNG_CPU(exynos4210, EXYNOS4210_CPU_ID, EXYNOS4_CPU_MASK)
> +IS_SAMSUNG_CPU(exynos4212, EXYNOS4212_CPU_ID, EXYNOS4_CPU_MASK)
> IS_SAMSUNG_CPU(exynos4412, EXYNOS4412_CPU_ID, EXYNOS4_CPU_MASK)
> IS_SAMSUNG_CPU(exynos5250, EXYNOS5250_SOC_ID, EXYNOS5_SOC_MASK)
> IS_SAMSUNG_CPU(exynos5410, EXYNOS5410_SOC_ID, EXYNOS5_SOC_MASK)
> @@ -52,6 +54,12 @@ IS_SAMSUNG_CPU(exynos5800, EXYNOS5800_SOC_ID, EXYNOS5_SOC_MASK)
> # define soc_is_exynos4210() 0
> #endif
>
> +#if defined(CONFIG_SOC_EXYNOS4212)
> +# define soc_is_exynos4212() is_samsung_exynos4212()
> +#else
> +# define soc_is_exynos4212() 0
> +#endif
> +
> #if defined(CONFIG_SOC_EXYNOS4412)
> # define soc_is_exynos4412() is_samsung_exynos4412()
> #else
> diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
> index 51a247ca4da8..5671621f1661 100644
> --- a/arch/arm/mach-exynos/exynos.c
> +++ b/arch/arm/mach-exynos/exynos.c
> @@ -178,6 +178,7 @@ static void __init exynos_dt_machine_init(void)
> exynos_cpuidle.dev.platform_data = &cpuidle_coupled_exynos_data;
> #endif
> if (of_machine_is_compatible("samsung,exynos4210") ||
> + of_machine_is_compatible("samsung,exynos4212") ||
> (of_machine_is_compatible("samsung,exynos4412") &&
> (of_machine_is_compatible("samsung,trats2") ||
> of_machine_is_compatible("samsung,midas") ||
> @@ -192,6 +193,7 @@ static char const *const exynos_dt_compat[] __initconst = {
> "samsung,exynos3250",
> "samsung,exynos4",
> "samsung,exynos4210",
> + "samsung,exynos4212",
> "samsung,exynos4412",
> "samsung,exynos5",
> "samsung,exynos5250",
> diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
> index 2da5b60b59e2..110c8064ee64 100644
> --- a/arch/arm/mach-exynos/firmware.c
> +++ b/arch/arm/mach-exynos/firmware.c
> @@ -63,12 +63,18 @@ static int exynos_cpu_boot(int cpu)
> *
> * On Exynos5 devices the call is ignored by trustzone firmware.
> */
> - if (!soc_is_exynos4210() && !soc_is_exynos4412())
> + if (!soc_is_exynos4210() && !soc_is_exynos4412() &&
> + !soc_is_exynos4212())

Seems more logical to have 4212 before 4412 here.

> return 0;
>
> /*
> * The second parameter of SMC_CMD_CPU1BOOT command means CPU id.
> + * But, Exynos4212 has only one secondary CPU so second parameter
> + * isn't used for informing secure firmware about CPU id.
> */
> + if (soc_is_exynos4212())
> + cpu = 0;

Is it necessary to set cpu = 0? Are there any obvious issues without
it (like second cpu not being brought up)? It seems vendor kernel
does this for both exynos4210 and exynos4212 [1], but mainline has not
done this for exynos4210 and there has been no reported issues on for
that platform as far as I know.

The assembly that handles SMC_CMD_CPU1BOOT in sboot.bin from firmware
version T310XXSBQB2 is identical to what is found in sboot.bin from
exynos4412-galaxy-s3, and it uses the cpu arg in both cases, so seems
likely that we need this and I am mostly asking out of curiosity.

[1] https://github.com/krzk/linux-vendor-backup/blob/mokee/android-3.4-samsung-galaxy-tab-s-10.5-sm-t805-exynos5420/arch/arm/mach-exynos/platsmp.c#L225-L229

Best regards,
Henrik Grimler

> exynos_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
> return 0;
> }
> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
> index 30f4e55bf39e..9b6db04e4e34 100644
> --- a/arch/arm/mach-exynos/pm.c
> +++ b/arch/arm/mach-exynos/pm.c
> @@ -161,7 +161,7 @@ void exynos_enter_aftr(void)
>
> exynos_pm_central_suspend();
>
> - if (soc_is_exynos4412()) {
> + if (soc_is_exynos4412() || soc_is_exynos4212()) {
> /* Setting SEQ_OPTION register */
> pmu_raw_writel(S5P_USE_STANDBY_WFI0 | S5P_USE_STANDBY_WFE0,
> S5P_CENTRAL_SEQ_OPTION);
> diff --git a/arch/arm/mach-exynos/suspend.c b/arch/arm/mach-exynos/suspend.c
> index 3bf14ca78b62..df1e10033f90 100644
> --- a/arch/arm/mach-exynos/suspend.c
> +++ b/arch/arm/mach-exynos/suspend.c
> @@ -231,6 +231,7 @@ static int __init exynos_pmu_irq_init(struct device_node *node,
>
> EXYNOS_PMU_IRQ(exynos3250_pmu_irq, "samsung,exynos3250-pmu");
> EXYNOS_PMU_IRQ(exynos4210_pmu_irq, "samsung,exynos4210-pmu");
> +EXYNOS_PMU_IRQ(exynos4212_pmu_irq, "samsung,exynos4212-pmu");
> EXYNOS_PMU_IRQ(exynos4412_pmu_irq, "samsung,exynos4412-pmu");
> EXYNOS_PMU_IRQ(exynos5250_pmu_irq, "samsung,exynos5250-pmu");
> EXYNOS_PMU_IRQ(exynos5420_pmu_irq, "samsung,exynos5420-pmu");
> @@ -640,6 +641,9 @@ static const struct of_device_id exynos_pmu_of_device_ids[] __initconst = {
> }, {
> .compatible = "samsung,exynos4210-pmu",
> .data = &exynos4_pm_data,
> + }, {
> + .compatible = "samsung,exynos4212-pmu",
> + .data = &exynos4_pm_data,
> }, {
> .compatible = "samsung,exynos4412-pmu",
> .data = &exynos4_pm_data,
> --
> 2.40.0
>