From 221869efc3a4cf975c1bf068227f17ce10cd5597 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Tue, 26 Apr 2022 16:37:41 +0200 Subject: [PATCH] ram: stm32mp1: Conditionally enable ASR Enable DRAM ASR, auto self-refresh, conditionally, based on DT PWRCTL register bits. While ASR does save considerable amount of power at runtime automatically, it also causes LTDC underruns on large panels. Let user select whether or not ASR is required or not, generally ASR should be enabled on portable and battery operated devices. Signed-off-by: Marek Vasut Cc: Patrick Delaunay Cc: Patrice Chotard Reviewed-by: Patrick Delaunay Signed-off-by: Patrice Chotard --- drivers/ram/stm32mp1/stm32mp1_ddr.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.c b/drivers/ram/stm32mp1/stm32mp1_ddr.c index 528a171b45..ab913a6876 100644 --- a/drivers/ram/stm32mp1/stm32mp1_ddr.c +++ b/drivers/ram/stm32mp1/stm32mp1_ddr.c @@ -653,10 +653,14 @@ static void stm32mp1_refresh_restore(struct stm32mp1_ddrctl *ctl, wait_sw_done_ack(ctl); } -static void stm32mp1_asr_enable(struct ddr_info *priv) +static void stm32mp1_asr_enable(struct ddr_info *priv, const u32 pwrctl) { struct stm32mp1_ddrctl *ctl = priv->ctl; + /* SSR is the best we can do. */ + if (!(pwrctl & DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE)) + return; + clrsetbits_le32(priv->rcc + RCC_DDRITFCR, RCC_DDRITFCR_DDRCKMOD_MASK, RCC_DDRITFCR_DDRCKMOD_ASR); @@ -666,8 +670,12 @@ static void stm32mp1_asr_enable(struct ddr_info *priv) writel(DDRCTRL_PWRTMG_POWERDOWN_TO_X32(0x10) | DDRCTRL_PWRTMG_SELFREF_TO_X32(0x01), &ctl->pwrtmg); + + /* HSR we can do. */ setbits_le32(&ctl->pwrctl, DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE); - setbits_le32(&ctl->pwrctl, DDRCTRL_PWRCTL_SELFREF_EN); + + if (pwrctl & DDRCTRL_PWRCTL_SELFREF_EN) /* ASR we can do. */ + setbits_le32(&ctl->pwrctl, DDRCTRL_PWRCTL_SELFREF_EN); setbits_le32(&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_INIT_COMPLETE_EN); wait_sw_done_ack(ctl); @@ -845,7 +853,7 @@ start: config->c_reg.pwrctl); /* Enable auto-self-refresh, which saves a bit of power at runtime. */ - stm32mp1_asr_enable(priv); + stm32mp1_asr_enable(priv, config->c_reg.pwrctl); /* enable uMCTL2 AXI port 0 and 1 */ setbits_le32(&priv->ctl->pctrl_0, DDRCTRL_PCTRL_N_PORT_EN); -- 2.39.5