Enable DRAM ASR, auto self-refresh, unconditionally. This saves non-trivial amount of power both at runtime and in suspend (on 2x W632GU6NB-15 ~150mW).
Reviewed-by: Patrice Chotard patrice.chotard@foss.st.com Signed-off-by: Marek Vasut marex@denx.de Cc: Patrick Delaunay patrick.delaunay@foss.st.com Cc: Patrice Chotard patrice.chotard@foss.st.com --- V2: Rebase on latest changes in this driver past v2022.01 V3: - Use GENMASK / BIT macros - Add RB from Patrice --- drivers/ram/stm32mp1/stm32mp1_ddr.c | 25 ++++++++++++++++++++++++ drivers/ram/stm32mp1/stm32mp1_ddr_regs.h | 6 ++++++ 2 files changed, 31 insertions(+)
diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.c b/drivers/ram/stm32mp1/stm32mp1_ddr.c index 4d78aa5cb13..528a171b454 100644 --- a/drivers/ram/stm32mp1/stm32mp1_ddr.c +++ b/drivers/ram/stm32mp1/stm32mp1_ddr.c @@ -27,6 +27,8 @@ #define RCC_DDRITFCR_DPHYAPBRST (BIT(17)) #define RCC_DDRITFCR_DPHYRST (BIT(18)) #define RCC_DDRITFCR_DPHYCTLRST (BIT(19)) +#define RCC_DDRITFCR_DDRCKMOD_MASK GENMASK(22, 20) +#define RCC_DDRITFCR_DDRCKMOD_ASR BIT(20)
struct reg_desc { const char *name; @@ -651,6 +653,26 @@ static void stm32mp1_refresh_restore(struct stm32mp1_ddrctl *ctl, wait_sw_done_ack(ctl); }
+static void stm32mp1_asr_enable(struct ddr_info *priv) +{ + struct stm32mp1_ddrctl *ctl = priv->ctl; + + clrsetbits_le32(priv->rcc + RCC_DDRITFCR, RCC_DDRITFCR_DDRCKMOD_MASK, + RCC_DDRITFCR_DDRCKMOD_ASR); + + start_sw_done(ctl); + + setbits_le32(&ctl->hwlpctl, DDRCTRL_HWLPCTL_HW_LP_EN); + writel(DDRCTRL_PWRTMG_POWERDOWN_TO_X32(0x10) | + DDRCTRL_PWRTMG_SELFREF_TO_X32(0x01), + &ctl->pwrtmg); + setbits_le32(&ctl->pwrctl, DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE); + setbits_le32(&ctl->pwrctl, DDRCTRL_PWRCTL_SELFREF_EN); + + setbits_le32(&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_INIT_COMPLETE_EN); + wait_sw_done_ack(ctl); +} + /* board-specific DDR power initializations. */ __weak int board_ddr_power_init(enum ddr_type ddr_type) { @@ -822,6 +844,9 @@ start: stm32mp1_refresh_restore(priv->ctl, config->c_reg.rfshctl3, config->c_reg.pwrctl);
+/* Enable auto-self-refresh, which saves a bit of power at runtime. */ + stm32mp1_asr_enable(priv); + /* enable uMCTL2 AXI port 0 and 1 */ setbits_le32(&priv->ctl->pctrl_0, DDRCTRL_PCTRL_N_PORT_EN); setbits_le32(&priv->ctl->pctrl_1, DDRCTRL_PCTRL_N_PORT_EN); diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr_regs.h b/drivers/ram/stm32mp1/stm32mp1_ddr_regs.h index f1a26e31f6c..42be1ba57c7 100644 --- a/drivers/ram/stm32mp1/stm32mp1_ddr_regs.h +++ b/drivers/ram/stm32mp1/stm32mp1_ddr_regs.h @@ -265,8 +265,14 @@ struct stm32mp1_ddrphy {
#define DDRCTRL_PWRCTL_SELFREF_EN BIT(0) #define DDRCTRL_PWRCTL_POWERDOWN_EN BIT(1) +#define DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE BIT(3) #define DDRCTRL_PWRCTL_SELFREF_SW BIT(5)
+#define DDRCTRL_PWRTMG_SELFREF_TO_X32(n) (((n) & 0xff) << 16) +#define DDRCTRL_PWRTMG_POWERDOWN_TO_X32(n) ((n) & 0x1f) + +#define DDRCTRL_HWLPCTL_HW_LP_EN BIT(0) + #define DDRCTRL_RFSHCTL3_DIS_AUTO_REFRESH BIT(0)
#define DDRCTRL_RFSHTMG_T_RFC_NOM_X1_X32_MASK GENMASK(27, 16)