Re: [PATCH v3 4/4] scsi: ufs-mediatek: gate ref-clk during Auto-Hibern8
From: Alim Akhtar <hidden>
Date: 2020-02-02 14:37:11
Also in:
linux-mediatek, linux-scsi, lkml
Hello Stanley On Wed, Jan 29, 2020 at 1:10 PM Stanley Chu [off-list ref] wrote:
In current UFS driver design, hba->uic_link_state will not be changed after link enters Hibern8 state by Auto-Hibern8 mechanism. In this case, reference clock gating will be skipped unless special handling is implemented in vendor's callbacks. Support reference clock gating during Auto-Hibern8 period in MediaTek Chipsets: If link state is already in Hibern8 while Auto-Hibern8 feature is enabled, gate reference clock in setup_clocks callback. Signed-off-by: Stanley Chu <redacted>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
quoted hunk ↗ jump to hunk
--- drivers/scsi/ufs/ufs-mediatek.c | 38 +++++++++++++++++++++++---------- drivers/scsi/ufs/ufs-mediatek.h | 12 +++++++++++ 2 files changed, 39 insertions(+), 11 deletions(-)diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c index d78897a14905..0ce08872d671 100644 --- a/drivers/scsi/ufs/ufs-mediatek.c +++ b/drivers/scsi/ufs/ufs-mediatek.c@@ -143,6 +143,17 @@ static int ufs_mtk_setup_ref_clk(struct ufs_hba *hba, bool on) return 0; } +static u32 ufs_mtk_link_get_state(struct ufs_hba *hba) +{ + u32 val; + + ufshcd_writel(hba, 0x20, REG_UFS_DEBUG_SEL); + val = ufshcd_readl(hba, REG_UFS_PROBE); + val = val >> 28; + + return val; +} + /** * ufs_mtk_setup_clocks - enables/disable clocks * @hba: host controller instance@@ -155,7 +166,7 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on, enum ufs_notify_change_status status) { struct ufs_mtk_host *host = ufshcd_get_variant(hba); - int ret = -EINVAL; + int ret = 0; /* * In case ufs_mtk_init() is not yet done, simply ignore.@@ -165,19 +176,24 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on, if (!host) return 0; - switch (status) { - case PRE_CHANGE: - if (!on && !ufshcd_is_link_active(hba)) { + if (!on && status == PRE_CHANGE) { + if (!ufshcd_is_link_active(hba)) { ufs_mtk_setup_ref_clk(hba, on); ret = phy_power_off(host->mphy); + } else { + /* + * Gate ref-clk if link state is in Hibern8 + * triggered by Auto-Hibern8. + */ + if (!ufshcd_can_hibern8_during_gating(hba) && + ufshcd_is_auto_hibern8_enabled(hba) && + ufs_mtk_link_get_state(hba) == + VS_LINK_HIBERN8) + ufs_mtk_setup_ref_clk(hba, on); } - break; - case POST_CHANGE: - if (on) { - ret = phy_power_on(host->mphy); - ufs_mtk_setup_ref_clk(hba, on); - } - break; + } else if (on && status == POST_CHANGE) { + ret = phy_power_on(host->mphy); + ufs_mtk_setup_ref_clk(hba, on); } return ret;diff --git a/drivers/scsi/ufs/ufs-mediatek.h b/drivers/scsi/ufs/ufs-mediatek.h index fccdd979d6fb..492414e5f481 100644 --- a/drivers/scsi/ufs/ufs-mediatek.h +++ b/drivers/scsi/ufs/ufs-mediatek.h@@ -53,6 +53,18 @@ #define VS_SAVEPOWERCONTROL 0xD0A6 #define VS_UNIPROPOWERDOWNCONTROL 0xD0A8 +/* + * Vendor specific link state + */ +enum { + VS_LINK_DISABLED = 0, + VS_LINK_DOWN = 1, + VS_LINK_UP = 2, + VS_LINK_HIBERN8 = 3, + VS_LINK_LOST = 4, + VS_LINK_CFG = 5, +}; + /* * SiP commands */ --2.18.0
-- Regards, Alim _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel