[PATCH 2/2] mmc: mediatek: add bus_clk control
From: chaotian.jing@mediatek.com (Chaotian Jing)
Date: 2018-09-28 11:41:20
Also in:
linux-devicetree, linux-mediatek, linux-mmc, lkml
Subsystem:
mediatek mmc/sd/sdio driver, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Chaotian Jing, Ulf Hansson, Linus Torvalds
when gate MSDC0_HCLK, access register will hang, even the MSDC driver will never accessing register after HCLK was gated, but for safety, need gate the bus_clk(which used to access register) too. Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> --- drivers/mmc/host/mtk-sd.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 0484138..1c1c967 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c@@ -387,6 +387,7 @@ struct msdc_host { struct clk *src_clk; /* msdc source clock */ struct clk *h_clk; /* msdc h_clk */ + struct clk *bus_clk; /* bus clock which used to access register */ struct clk *src_clk_cg; /* msdc source clock control gate */ u32 mclk; /* mmc subsystem clock frequency */ u32 src_clk_freq; /* source clock frequency */
@@ -660,12 +661,14 @@ static void msdc_gate_clock(struct msdc_host *host) { clk_disable_unprepare(host->src_clk_cg); clk_disable_unprepare(host->src_clk); + clk_disable_unprepare(host->bus_clk); clk_disable_unprepare(host->h_clk); } static void msdc_ungate_clock(struct msdc_host *host) { clk_prepare_enable(host->h_clk); + clk_prepare_enable(host->bus_clk); clk_prepare_enable(host->src_clk); clk_prepare_enable(host->src_clk_cg); while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
@@ -1900,6 +1903,9 @@ static int msdc_drv_probe(struct platform_device *pdev) goto host_free; } + host->bus_clk = devm_clk_get(&pdev->dev, "bus_clk"); + if (IS_ERR(host->bus_clk)) + host->bus_clk = NULL; /*source clock control gate is optional clock*/ host->src_clk_cg = devm_clk_get(&pdev->dev, "source_cg"); if (IS_ERR(host->src_clk_cg))
--
1.8.1.1.dirty