[U-Boot] [RESEND 2/3] imx: mx7: add gpc initialization for low power mode

[Stefan Agner]

On 07.08.2018 08:46, Anson Huang wrote:
> Add i.MX7D GPC initialization for low power mode
> support like system suspend/resume from linux kernel:
> 
>  - Pending IOMUXC IRQ to workaround GPC state machine issue;
>  - Mask all GPC interrupts for M4/C0/C1;
>  - Configure SCU timing;
>  - Configure time slot ack;
>  - Configure C0/C1 power up/down timing;
>  - Configure wakeup source mechanism;
>  - Disable DSM/RBC related settings.
> 
> Signed-off-by: Anson Huang <Anson.Huang at nxp.com>
> ---
>  arch/arm/mach-imx/mx7/soc.c | 101 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 101 insertions(+)
> 
> diff --git a/arch/arm/mach-imx/mx7/soc.c b/arch/arm/mach-imx/mx7/soc.c
> index 7334ca9..a829da2 100644
> --- a/arch/arm/mach-imx/mx7/soc.c
> +++ b/arch/arm/mach-imx/mx7/soc.c
> @@ -18,6 +18,37 @@
>  #include <fsl_sec.h>
>  #include <asm/setup.h>
>  
> +#define IOMUXC_GPR1		0x4
> +#define BM_IOMUXC_GPR1_IRQ	0x1000
> +
> +#define GPC_LPCR_A7_BSC		0x0
> +#define GPC_LPCR_M4		0x8
> +#define GPC_SLPCR		0x14
> +#define GPC_PGC_ACK_SEL_A7	0x24
> +#define GPC_IMR1_CORE0		0x30
> +#define GPC_IMR1_CORE1		0x40
> +#define GPC_IMR1_M4		0x50
> +#define GPC_PGC_CPU_MAPPING	0xec
> +#define GPC_PGC_C0_PUPSCR	0x804
> +#define GPC_PGC_SCU_TIMING	0x890
> +#define GPC_PGC_C1_PUPSCR	0x844
> +
> +#define BM_LPCR_A7_BSC_IRQ_SRC_A7_WAKEUP	0x70000000
> +#define BM_LPCR_A7_BSC_CPU_CLK_ON_LPM		0x4000
> +#define BM_LPCR_M4_MASK_DSM_TRIGGER		0x80000000
> +#define BM_SLPCR_EN_DSM				0x80000000
> +#define BM_SLPCR_RBC_EN				0x40000000
> +#define BM_SLPCR_REG_BYPASS_COUNT		0x3f000000
> +#define BM_SLPCR_VSTBY				0x4
> +#define BM_SLPCR_SBYOS				0x2
> +#define BM_SLPCR_BYPASS_PMIC_READY		0x1
> +#define BM_SLPCR_EN_A7_FASTWUP_WAIT_MODE	0x10000
> +
> +#define BM_GPC_PGC_ACK_SEL_A7_DUMMY_PUP_ACK	0x80000000
> +#define BM_GPC_PGC_ACK_SEL_A7_DUMMY_PDN_ACK	0x8000
> +
> +#define BM_GPC_PGC_CORE_PUPSCR			0x7fff80
> +
>  #if defined(CONFIG_IMX_THERMAL)
>  static const struct imx_thermal_plat imx7_thermal_plat = {
>  	.regs = (void *)ANATOP_BASE_ADDR,
> @@ -159,6 +190,74 @@ static void imx_enet_mdio_fixup(void)
>  	}
>  }
>  
> +static void imx_gpcv2_init(void)
> +{
> +	u32 val, i;
> +
> +	/*
> +	 * Force IOMUXC irq pending, so that the interrupt to GPC can be
> +	 * used to deassert dsm_request signal when the signal gets
> +	 * asserted unexpectedly.
> +	 */

Does this issue has an errata associated to it? If yes, could we add
then number?

> +	val = readl(IOMUXC_GPR_BASE_ADDR + IOMUXC_GPR1);
> +	val |= BM_IOMUXC_GPR1_IRQ;
> +	writel(val, IOMUXC_GPR_BASE_ADDR + IOMUXC_GPR1);
> +
> +	/* Initially mask all interrupts */
> +	for (i = 0; i < 4; i++) {
> +		writel(~0, GPC_IPS_BASE_ADDR + GPC_IMR1_CORE0 + i * 4);
> +		writel(~0, GPC_IPS_BASE_ADDR + GPC_IMR1_CORE1 + i * 4);
> +		writel(~0, GPC_IPS_BASE_ADDR + GPC_IMR1_M4 + i * 4);
> +	}
> +
> +	/* set SCU timing */
> +	writel((0x59 << 10) | 0x5B | (0x2 << 20),
> +	       GPC_IPS_BASE_ADDR + GPC_PGC_SCU_TIMING);
> +
> +	/* only external IRQs to wake up LPM and core 0/1 */
> +	val = readl(GPC_IPS_BASE_ADDR + GPC_LPCR_A7_BSC);
> +	val |= BM_LPCR_A7_BSC_IRQ_SRC_A7_WAKEUP;
> +	writel(val, GPC_IPS_BASE_ADDR + GPC_LPCR_A7_BSC);
> +
> +	/* set C0 power up timming per design requirement */
> +	val = readl(GPC_IPS_BASE_ADDR + GPC_PGC_C0_PUPSCR);
> +	val &= ~BM_GPC_PGC_CORE_PUPSCR;
> +	val |= (0x1A << 7);
> +	writel(val, GPC_IPS_BASE_ADDR + GPC_PGC_C0_PUPSCR);
> +
> +	/* set C1 power up timming per design requirement */
> +	val = readl(GPC_IPS_BASE_ADDR + GPC_PGC_C1_PUPSCR);
> +	val &= ~BM_GPC_PGC_CORE_PUPSCR;
> +	val |= (0x1A << 7);
> +	writel(val, GPC_IPS_BASE_ADDR + GPC_PGC_C1_PUPSCR);
> +
> +	/* dummy ack for time slot by default */
> +	writel(BM_GPC_PGC_ACK_SEL_A7_DUMMY_PUP_ACK |
> +		BM_GPC_PGC_ACK_SEL_A7_DUMMY_PDN_ACK,
> +		GPC_IPS_BASE_ADDR + GPC_PGC_ACK_SEL_A7);
> +
> +	/* mask M4 DSM trigger */
> +	writel(readl(GPC_IPS_BASE_ADDR + GPC_LPCR_M4) |
> +		 BM_LPCR_M4_MASK_DSM_TRIGGER,
> +		 GPC_IPS_BASE_ADDR + GPC_LPCR_M4);
> +
> +	/* set mega/fast mix in A7 domain */
> +	writel(0x1, GPC_IPS_BASE_ADDR + GPC_PGC_CPU_MAPPING);

newline...

> +	/* DSM related settings */
> +	val = readl(GPC_IPS_BASE_ADDR + GPC_SLPCR);
> +	val &= ~(BM_SLPCR_EN_DSM | BM_SLPCR_VSTBY | BM_SLPCR_RBC_EN |
> +		BM_SLPCR_SBYOS | BM_SLPCR_BYPASS_PMIC_READY |
> +		BM_SLPCR_REG_BYPASS_COUNT);

I guess BM_SLPCR_RBC_EN is to work around e10133? Maybe we can note
that.

> +	val |= BM_SLPCR_EN_A7_FASTWUP_WAIT_MODE;
> +	writel(val, GPC_IPS_BASE_ADDR + GPC_SLPCR);

newline...

> +	/*
> +	 * disabling RBC need to delay at least 2 cycles of CKIL(32K)
> +	 * due to hardware design requirement, which is
> +	 * ~61us, here we use 65us for safe
> +	 */
> +	udelay(65);
> +}
> +
>  int arch_cpu_init(void)
>  {
>  	init_aips();
> @@ -180,6 +279,8 @@ int arch_cpu_init(void)
>  
>  	init_snvs();
>  
> +	imx_gpcv2_init();
> +
>  	return 0;
>  }