[PATCH] ram: stm32mp1: Conditionally enable ASR
Patrick DELAUNAY
patrick.delaunay at foss.st.com
Thu Apr 14 18:37:08 CEST 2022
Hi Marek,
on ST platform the ASR/SSR/HSR request are already provided by the DDR
settings with pwrctl register value
it is managed in TF-A by
arm-trusted-firmware/drivers/st/ddr/stm32mp1_ddr_helpers.c
enumstm32mp1_ddr_sr_mode ddr_read_sr_mode(void)
{
uint32_tpwrctl = mmio_read_32(stm32mp_ddrctrl_base() + DDRCTRL_PWRCTL);
switch(pwrctl & (DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE |
DDRCTRL_PWRCTL_SELFREF_EN)) {
case0U:
returnDDR_SSR_MODE;
caseDDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE:
returnDDR_HSR_MODE;
caseDDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE | DDRCTRL_PWRCTL_SELFREF_EN:
returnDDR_ASR_MODE;
default:
returnDDR_SR_MODE_INVALID;
}
}
no need to add an other property
I think
On 4/13/22 04:49, Marek Vasut wrote:
> Enable DRAM ASR, auto self-refresh, conditionally, based on DT property
> "st,mem-enable-asr" . 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 <marex at denx.de>
> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Cc: Patrice Chotard <patrice.chotard at foss.st.com>
> ---
> drivers/ram/stm32mp1/stm32mp1_ddr.c | 3 ++-
> drivers/ram/stm32mp1/stm32mp1_ddr.h | 1 +
> drivers/ram/stm32mp1/stm32mp1_ram.c | 1 +
> 3 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.c b/drivers/ram/stm32mp1/stm32mp1_ddr.c
> index 528a171b454..fd11e02aff4 100644
> --- a/drivers/ram/stm32mp1/stm32mp1_ddr.c
> +++ b/drivers/ram/stm32mp1/stm32mp1_ddr.c
> @@ -845,7 +845,8 @@ start:
> config->c_reg.pwrctl);
>
> /* Enable auto-self-refresh, which saves a bit of power at runtime. */
> - stm32mp1_asr_enable(priv);
+ if (config->c_reg.pwrctl & (DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE |
DDRCTRL_PWRCTL_SELFREF_SW) ==
(DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE |DDRCTRL_PWRCTL_SELFREF_SW))
+ stm32mp1_asr_enable(priv);
in DDR setting
#define DDR_PWRCTL 0x00000000
=> SSR
#define DDR_PWRCTL 0x00000028
=> ASR
> + if (config->info.enable_asr)
> + stm32mp1_asr_enable(priv);
>
> /* enable uMCTL2 AXI port 0 and 1 */
> setbits_le32(&priv->ctl->pctrl_0, DDRCTRL_PCTRL_N_PORT_EN);
> diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.h b/drivers/ram/stm32mp1/stm32mp1_ddr.h
> index 861efff92be..c74a9cea2cc 100644
> --- a/drivers/ram/stm32mp1/stm32mp1_ddr.h
> +++ b/drivers/ram/stm32mp1/stm32mp1_ddr.h
> @@ -144,6 +144,7 @@ struct stm32mp1_ddr_info {
> const char *name;
> u32 speed; /* in kHZ */
> u32 size; /* memory size in byte = col * row * width */
> + bool enable_asr;
> };
>
> struct stm32mp1_ddr_config {
> diff --git a/drivers/ram/stm32mp1/stm32mp1_ram.c b/drivers/ram/stm32mp1/stm32mp1_ram.c
> index 49b1262461b..f39cfad4764 100644
> --- a/drivers/ram/stm32mp1/stm32mp1_ram.c
> +++ b/drivers/ram/stm32mp1/stm32mp1_ram.c
> @@ -122,6 +122,7 @@ static int stm32mp1_ddr_setup(struct udevice *dev)
> config.info.speed = ofnode_read_u32_default(node, "st,mem-speed", 0);
> config.info.size = ofnode_read_u32_default(node, "st,mem-size", 0);
> config.info.name = ofnode_read_string(node, "st,mem-name");
> + config.info.enable_asr = ofnode_read_bool(node, "st,mem-enable-asr");
> if (!config.info.name) {
> dev_dbg(dev, "no st,mem-name\n");
> return -EINVAL;
Regards
Patrick
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