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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>
This commit is contained in:
Chaotian Jing 2017-10-16 09:46:36 +08:00 committed by Ulf Hansson
parent d9dcbfc880
commit 3c1a884436
1 changed files with 22 additions and 1 deletions
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23
drivers/mmc/host/mtk-sd.c
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@ -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;