diff options
author | Chaotian Jing <chaotian.jing@mediatek.com> | 2017-10-16 09:46:36 +0800 |
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committer | Ulf Hansson <ulf.hansson@linaro.org> | 2017-11-02 15:20:25 +0100 |
commit | 3c1a8844369880d077f858f448afc4ef553d962a (patch) | |
tree | c6e483bbf89b0e45c3bc5693306eb9651c077796 /drivers/mmc | |
parent | d9dcbfc880126b193eab418d7b64b3774cb57152 (diff) | |
download | blackbird-op-linux-3c1a8844369880d077f858f448afc4ef553d962a.tar.gz blackbird-op-linux-3c1a8844369880d077f858f448afc4ef553d962a.zip |
mmc: mediatek: add support of source_cg clock
source clock need an independent cg to control, when doing clk mode
switch, need gate source clock to avoid hw issue(multi-bit sync hw hang)
Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Tested-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r-- | drivers/mmc/host/mtk-sd.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c index d519fa5dbf52..df57481b0dda 100644 --- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c @@ -372,6 +372,7 @@ struct msdc_host { struct clk *src_clk; /* msdc source clock */ struct clk *h_clk; /* msdc h_clk */ + struct clk *src_clk_cg; /* msdc source clock control gate */ u32 mclk; /* mmc subsystem clock frequency */ u32 src_clk_freq; /* source clock frequency */ u32 sclk; /* SD/MS bus clock frequency */ @@ -616,6 +617,7 @@ static void msdc_set_timeout(struct msdc_host *host, u32 ns, u32 clks) 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->h_clk); } @@ -624,6 +626,7 @@ static void msdc_ungate_clock(struct msdc_host *host) { clk_prepare_enable(host->h_clk); clk_prepare_enable(host->src_clk); + clk_prepare_enable(host->src_clk_cg); while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB)) cpu_relax(); } @@ -692,6 +695,15 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz) sclk = (host->src_clk_freq >> 2) / div; } } + sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN); + /* + * As src_clk/HCLK use the same bit to gate/ungate, + * So if want to only gate src_clk, need gate its parent(mux). + */ + if (host->src_clk_cg) + clk_disable_unprepare(host->src_clk_cg); + else + clk_disable_unprepare(clk_get_parent(host->src_clk)); if (host->dev_comp->clk_div_bits == 8) sdr_set_field(host->base + MSDC_CFG, MSDC_CFG_CKMOD | MSDC_CFG_CKDIV, @@ -700,10 +712,14 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz) sdr_set_field(host->base + MSDC_CFG, MSDC_CFG_CKMOD_EXTRA | MSDC_CFG_CKDIV_EXTRA, (mode << 12) | div); + if (host->src_clk_cg) + clk_prepare_enable(host->src_clk_cg); + else + clk_prepare_enable(clk_get_parent(host->src_clk)); - sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN); while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB)) cpu_relax(); + sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN); host->sclk = sclk; host->mclk = hz; host->timing = timing; @@ -1822,6 +1838,11 @@ static int msdc_drv_probe(struct platform_device *pdev) goto host_free; } + /*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)) + host->src_clk_cg = NULL; + host->irq = platform_get_irq(pdev, 0); if (host->irq < 0) { ret = -EINVAL; |