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authorChaotian Jing <chaotian.jing@mediatek.com>2017-10-16 09:46:36 +0800
committerUlf Hansson <ulf.hansson@linaro.org>2017-11-02 15:20:25 +0100
commit3c1a8844369880d077f858f448afc4ef553d962a (patch)
treec6e483bbf89b0e45c3bc5693306eb9651c077796 /drivers/mmc
parentd9dcbfc880126b193eab418d7b64b3774cb57152 (diff)
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.c23
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;