[PATCH v5 2/3] arm: exynos5: Add Suspend-to-RAM support for 5420
Vikas Sajjan
vikas.sajjan at samsung.com
Tue Jul 1 06:47:51 PDT 2014
Hi Tomasz,
On Mon, Jun 30, 2014 at 11:27 PM, Tomasz Figa <t.figa at samsung.com> wrote:
> Hi Vikas, Abhilash,
>
> Please see my comments inline.
>
> On 26.06.2014 13:12, Vikas Sajjan wrote:
>> From: Abhilash Kesavan <a.kesavan at samsung.com>
>>
>> Adds Suspend-to-RAM support for EXYNOS5420
>>
>> Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
>> Signed-off-by: Vikas Sajjan <vikas.sajjan at samsung.com>
>> ---
>> arch/arm/mach-exynos/pm.c | 150 ++++++++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 134 insertions(+), 16 deletions(-)
>>
>> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
>> index de61d48..bf8564a 100644
>> --- a/arch/arm/mach-exynos/pm.c
>> +++ b/arch/arm/mach-exynos/pm.c
>> @@ -38,9 +38,13 @@
>> #include "regs-pmu.h"
>> #include "regs-sys.h"
>>
>> +#define EXYNOS5420_CPU_STATE 0x28
>> +
>> #define pmu_raw_writel(val, offset) \
>> __raw_writel(val, pmu_base_addr + offset)
>>
>> +static int exynos5420_cpu_state;
>> +
>> /**
>> * struct exynos_wkup_irq - Exynos GIC to PMU IRQ mapping
>> * @hwirq: Hardware IRQ signal of the GIC
>> @@ -64,6 +68,10 @@ static struct sleep_save exynos_core_save[] = {
>> SAVE_ITEM(S5P_SROM_BC3),
>> };
>>
>> +static struct sleep_save exynos5420_pmu_reg_save[] = {
>> + SAVE_ITEM((void __iomem *)S5P_PMU_SPARE3),
>> +};
>
> Do you need a whole array for this single register?
>
>> +
>> /*
>> * GIC wake-up support
>> */
>> @@ -86,7 +94,7 @@ static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
>> {
>> const struct exynos_wkup_irq *wkup_irq;
>>
>> - if (soc_is_exynos5250())
>> + if (soc_is_exynos5250() || soc_is_exynos5420())
>
> You should rework this to eliminate the need to use any SoC-specific
> checks. For example:
>
> 1) create a struct where any SoC/family specific data are stored, e.g.
>
> struct exynos_pm_data {
> const struct exynos_wkup_irq *wkup_irq;
> /* arrays, flags, values, function pointers, etc. */
> };
>
> 2) describe supported variants using instances of this struct, e.g.
>
> static const struct exynos_pm_data exynos5250_pm_data {
> .wkup_irq = exynos5250_wkup_irq,
> /* ... */
> };
>
> static const struct exynos_pm_data exynos5420_pm_data {
> .wkup_irq = exynos5250_wkup_irq,
> /* ... */
> };
>
> 3) put pointers to those structs in DT match table:
>
> static const struct of_device_id exynos_pm_matches[] = {
> { .compatible = "samsung,exynos5250-pmu",
> .data = &exynos5250_pm_data },
> { .compatible = "samsung,exynos5420-pmu",
> .data = &exynos5420_pm_data },
> };
>
> 4) find a matching node in DT and use the struct pointed by match data.
>
> Also certain checks could probably be replaced with non-SoC-specific
> checks, e.g. by CPU part checks.
>
>> wkup_irq = exynos5250_wkup_irq;
>> else
>> wkup_irq = exynos4_wkup_irq;
>> @@ -250,7 +258,16 @@ static int exynos_cpu_suspend(unsigned long arg)
>> outer_flush_all();
>> #endif
>>
>> - if (soc_is_exynos5250())
>> + /*
>> + * Clear sysram register for cpu state so that primary CPU does
>> + * not enter low power start in U-Boot.
>> + * This is specific to exynos5420 SoC only.
>> + */
>> + if (soc_is_exynos5420())
>> + __raw_writel(0x0,
>> + sysram_base_addr + EXYNOS5420_CPU_STATE);
>> +
>> + if (soc_is_exynos5250() || soc_is_exynos5420())
>
> This probably can be replaced with a check for Cortex A15 or A7.
>
>> flush_cache_all();
>>
>> /* issue the standby signal into the pm unit. */
>> @@ -276,6 +293,22 @@ static void exynos_pm_prepare(void)
>> tmp = __raw_readl(pmu_base_addr + EXYNOS5_JPEG_MEM_OPTION);
>> tmp &= ~EXYNOS5_OPTION_USE_RETENTION;
>> pmu_raw_writel(tmp, EXYNOS5_JPEG_MEM_OPTION);
>> + } else if (soc_is_exynos5420()) {
>> + unsigned int i;
I have a question here.
I can come up with a function like exynos5420_pm_prepare(), which does
the same as the code under this if condition.
call it here like below,
static void exynos_pm_prepare(void)
{
/* common to all SoCs */
......
.....
......
/* specific to given SoC */
exynos_pm_data->pm_prepare();
........
.......
.......
}
but at line -286,6 +319,27 @@ static void exynos_pm_prepare(void)
also we have something specific to 5420.
how do we handle such cases. Because in future there may be new a SoC
which does SoC specific things at 3 different
location in same function exynos_pm_prepare().
This will also apply to function like exynos_pm_suspend()
exynos_pm_resume() etc.,
>> +
>> + for (i = 0; i < ARRAY_SIZE(exynos5420_pmu_reg_save); i++)
>> + exynos5420_pmu_reg_save[i].val =
>> + __raw_readl(pmu_base_addr +
>> + (unsigned int)exynos5420_pmu_reg_save[i].reg);
>> + /*
>> + * The cpu state needs to be saved and restored so that the
>> + * secondary CPUs will enter low power start. Though the U-Boot
>> + * is setting the cpu state with low power flag, the kernel
>> + * needs to restore it back in case, the primary cpu fails to
>> + * suspend for any reason.
>> + */
>> + exynos5420_cpu_state =
>> + __raw_readl(sysram_base_addr + EXYNOS5420_CPU_STATE);
>> }
>>
>> /* Set value of power down register for sleep mode */
>> @@ -286,6 +319,27 @@ static void exynos_pm_prepare(void)
>> /* ensure at least INFORM0 has the resume address */
>>
>> pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
>> +
>> + if (soc_is_exynos5420()) {
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
>> + tmp &= ~EXYNOS5_USE_RETENTION;
>> + pmu_raw_writel(tmp, EXYNOS5_ARM_L2_OPTION);
>> +
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5420_SFR_AXI_CGDIS1);
>> + tmp |= EXYNOS5420_UFS;
>> + pmu_raw_writel(tmp, EXYNOS5420_SFR_AXI_CGDIS1);
>> +
>> + tmp = __raw_readl(pmu_base_addr +
>> + EXYNOS5420_ARM_COMMON_OPTION);
>> + tmp &= ~EXYNOS5420_L2RSTDISABLE_VALUE;
>> + pmu_raw_writel(tmp, EXYNOS5420_ARM_COMMON_OPTION);
>
> nit: A blank line here could improve readability.
>
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5420_FSYS2_OPTION);
>> + tmp |= EXYNOS5420_EMULATION;
>> + pmu_raw_writel(tmp, EXYNOS5420_FSYS2_OPTION);
>
> nit: A blank line here could improve readability.
>
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5420_PSGEN_OPTION);
>> + tmp |= EXYNOS5420_EMULATION;
>> + pmu_raw_writel(tmp, EXYNOS5420_PSGEN_OPTION);
>> + }
>> }
>>
>> static void exynos_pm_central_suspend(void)
>> @@ -301,13 +355,24 @@ static void exynos_pm_central_suspend(void)
>> static int exynos_pm_suspend(void)
>> {
>> unsigned long tmp;
>> + unsigned int this_cluster;
>
> nit: Two spaces between "int" and "this_cluster". Also it might be a
> better idea to use explicitly sized types with same size as register width.
>
>>
>> exynos_pm_central_suspend();
>>
>> /* Setting SEQ_OPTION register */
>>
>> - tmp = (S5P_USE_STANDBY_WFI0 | S5P_USE_STANDBY_WFE0);
>> - pmu_raw_writel(tmp, S5P_CENTRAL_SEQ_OPTION);
>> + if (soc_is_exynos5420()) {
>
> I believe this is not Exynos5420-specific, but rather specific to any
> multi-cluster Exynos SoC. I think there might be a way to check the
> number of clusters.
>
>> + this_cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1);
>> + if (!this_cluster)
>> + pmu_raw_writel(EXYNOS5420_ARM_USE_STANDBY_WFI0,
>> + S5P_CENTRAL_SEQ_OPTION);
>> + else
>> + pmu_raw_writel(EXYNOS5420_KFC_USE_STANDBY_WFI0,
>> + S5P_CENTRAL_SEQ_OPTION);
>
> By the way, is it even possible to boot this SoC using other CPU than
> first Cortex A15?
>
>> + } else {
>> + tmp = (S5P_USE_STANDBY_WFI0 | S5P_USE_STANDBY_WFE0);
>> + pmu_raw_writel(tmp, S5P_CENTRAL_SEQ_OPTION);
>> + }
>>
>> if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
>> exynos_cpu_save_register();
>> @@ -340,6 +405,17 @@ static int exynos_pm_central_resume(void)
>>
>> static void exynos_pm_resume(void)
>> {
>> + unsigned int tmp;
>> +
>> + if (soc_is_exynos5420()) {
>> + /* Restore the sysram cpu state register */
>> + __raw_writel(exynos5420_cpu_state,
>> + sysram_base_addr + EXYNOS5420_CPU_STATE);
>> +
>> + pmu_raw_writel(EXYNOS5420_USE_STANDBY_WFI_ALL,
>> + S5P_CENTRAL_SEQ_OPTION);
>> + }
>> +
>> if (exynos_pm_central_resume())
>> goto early_wakeup;
>>
>> @@ -347,18 +423,42 @@ static void exynos_pm_resume(void)
>> exynos_cpu_restore_register();
>>
>> /* For release retention */
>> + if (soc_is_exynos5420()) {
>> + pmu_raw_writel((1 << 28), EXYNOS_PAD_RET_DRAM_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS_PAD_RET_MAUDIO_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS_PAD_RET_JTAG_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_GPIO_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_UART_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_MMCA_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_MMCB_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_MMCC_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_HSI_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS_PAD_RET_EBIA_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS_PAD_RET_EBIB_OPTION);
>> + pmu_raw_writel((1 << 28), EXYNOS5420_PAD_RET_SPI_OPTION);
>> + pmu_raw_writel((1 << 28),
>> + EXYNOS5420_PAD_RET_DRAM_COREBLK_OPTION);
>
> This could be replaced with an array of registers that is specified in
> the exynos_pm_data struct. Also while at it, the (1 << 28) could be
> replaced with proper macro.
>
>> + } else {
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_MAUDIO_OPTION);
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_GPIO_OPTION);
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_UART_OPTION);
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_MMCA_OPTION);
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_MMCB_OPTION);
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_EBIA_OPTION);
>> + pmu_raw_writel((1 << 28), S5P_PAD_RET_EBIB_OPTION);
>> + }
>>
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_MAUDIO_OPTION);
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_GPIO_OPTION);
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_UART_OPTION);
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_MMCA_OPTION);
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_MMCB_OPTION);
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_EBIA_OPTION);
>> - pmu_raw_writel((1 << 28), S5P_PAD_RET_EBIB_OPTION);
>> -
>> - if (soc_is_exynos5250())
>> + if (soc_is_exynos5250()) {
>> s3c_pm_do_restore(exynos5_sys_save,
>> ARRAY_SIZE(exynos5_sys_save));
>> + } else if (soc_is_exynos5420()) {
>> + unsigned int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(exynos5420_pmu_reg_save); i++)
>> + pmu_raw_writel(
>> + (unsigned int)exynos5420_pmu_reg_save[i].val,
>> + (unsigned int)exynos5420_pmu_reg_save[i].reg);
>> + }
>>
>> s3c_pm_do_restore_core(exynos_core_save, ARRAY_SIZE(exynos_core_save));
>>
>> @@ -367,6 +467,18 @@ static void exynos_pm_resume(void)
>>
>> early_wakeup:
>>
>> + if (soc_is_exynos5420()) {
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5420_SFR_AXI_CGDIS1);
>> + tmp &= ~EXYNOS5420_UFS;
>> + pmu_raw_writel(tmp, EXYNOS5420_SFR_AXI_CGDIS1);
>
> nit: Spacing here would be nice.
>
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5420_FSYS2_OPTION);
>> + tmp &= ~EXYNOS5420_EMULATION;
>> + pmu_raw_writel(tmp, EXYNOS5420_FSYS2_OPTION);
>
> Ditto.
>
>> + tmp = __raw_readl(pmu_base_addr + EXYNOS5420_PSGEN_OPTION);
>> + tmp &= ~EXYNOS5420_EMULATION;
>> + pmu_raw_writel(tmp, EXYNOS5420_PSGEN_OPTION);
>> + }
>> +
>> /* Clear SLEEP mode set in INFORM1 */
>> pmu_raw_writel(0x0, S5P_INFORM1);
>>
>> @@ -483,9 +595,15 @@ void __init exynos_pm_init(void)
>> gic_arch_extn.irq_set_wake = exynos_irq_set_wake;
>>
>> /* All wakeup disable */
>> - tmp = __raw_readl(pmu_base_addr + S5P_WAKEUP_MASK);
>> - tmp |= ((0xFF << 8) | (0x1F << 1));
>> - pmu_raw_writel(tmp, S5P_WAKEUP_MASK);
>> + if (soc_is_exynos5420()) {
>> + tmp = __raw_readl(pmu_base_addr + S5P_WAKEUP_MASK);
>> + tmp |= ((0x7F << 7) | (0x1F << 1));
>
> This mask could be also moved to the struct.
>
> Best regards,
> Tomasz
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