Messages in this thread Patch in this message | | | From | <> | Subject | [PATCH v2 2/2] soc: mediatek: add a fixed wait for SRAM stable | Date | Mon, 23 Apr 2018 16:36:22 +0800 |
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From: Sean Wang <sean.wang@mediatek.com>
MT7622_POWER_DOMAIN_WB doesn't send an ACK when its managed SRAM becomes stable, which is not like the behavior the other power domains should have. Therefore, it's necessary for such a power domain to have a fixed and well-predefined duration to wait until its managed SRAM can be allowed to access by all functions running on the top.
v1 -> v2: - use MTK_SCPD_FWAIT_SRAM flag as an indication requiring force waiting.
Signed-off-by: Sean Wang <sean.wang@mediatek.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Weiyi Lu <weiyi.lu@mediatek.com> --- drivers/soc/mediatek/mtk-scpsys.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c index b1b45e4..d4f1a63 100644 --- a/drivers/soc/mediatek/mtk-scpsys.c +++ b/drivers/soc/mediatek/mtk-scpsys.c @@ -32,6 +32,7 @@ #define MTK_POLL_TIMEOUT (jiffies_to_usecs(HZ)) #define MTK_SCPD_ACTIVE_WAKEUP BIT(0) +#define MTK_SCPD_FWAIT_SRAM BIT(1) #define MTK_SCPD_CAPS(_scpd, _x) ((_scpd)->data->caps & (_x)) #define SPM_VDE_PWR_CON 0x0210 @@ -237,11 +238,22 @@ static int scpsys_power_on(struct generic_pm_domain *genpd) val &= ~scpd->data->sram_pdn_bits; writel(val, ctl_addr); - /* wait until SRAM_PDN_ACK all 0 */ - ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == 0, - MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT); - if (ret < 0) - goto err_pwr_ack; + /* Either wait until SRAM_PDN_ACK all 0 or have a force wait */ + if (!MTK_SCPD_CAPS(scpd, MTK_SCPD_FWAIT_SRAM)) { + ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == 0, + MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT); + if (ret < 0) + goto err_pwr_ack; + } else { + /* + * Currently, MTK_SCPD_FWAIT_SRAM is necessary only for + * MT7622_POWER_DOMAIN_WB and thus just a trivial setup is + * applied here. If there're more domains which need to force + * waiting for its own pre-defined value, the duration should + * be coded in the caps field. + */ + usleep_range(12000, 12100); + }; if (scpd->data->bus_prot_mask) { ret = mtk_infracfg_clear_bus_protection(scp->infracfg, @@ -785,7 +797,7 @@ static const struct scp_domain_data scp_domain_data_mt7622[] = { .sram_pdn_ack_bits = 0, .clk_id = {CLK_NONE}, .bus_prot_mask = MT7622_TOP_AXI_PROT_EN_WB, - .caps = MTK_SCPD_ACTIVE_WAKEUP, + .caps = MTK_SCPD_ACTIVE_WAKEUP | MTK_SCPD_FWAIT_SRAM, }, }; -- 2.7.4
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