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mmc: sh_mobile_sdhi: add support for 2 clocks 

Some controllers have 2 clock sources instead of 1. The 2nd clock
is for the internal card detect logic and must be enabled/disabled
along with the main core clock for proper operation.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
This commit is contained in:
Chris Brandt 2017-01-25 15:28:08 -05:00 committed by Ulf Hansson
parent dc012058d7
commit 34a1654706
1 changed files with 23 additions and 0 deletions
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23
drivers/mmc/host/sh_mobile_sdhi.c
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@ -143,6 +143,7 @@ MODULE_DEVICE_TABLE(of, sh_mobile_sdhi_of_match);
struct sh_mobile_sdhi {
struct clk *clk;
struct clk *clk_cd;
struct tmio_mmc_data mmc_data;
struct tmio_mmc_dma dma_priv;
struct pinctrl *pinctrl;
@ -190,6 +191,12 @@ static int sh_mobile_sdhi_clk_enable(struct tmio_mmc_host *host)
if (ret < 0)
return ret;
ret = clk_prepare_enable(priv->clk_cd);
if (ret < 0) {
clk_disable_unprepare(priv->clk);
return ret;
}
/*
* The clock driver may not know what maximum frequency
* actually works, so it should be set with the max-frequency
@ -255,6 +262,7 @@ static void sh_mobile_sdhi_clk_disable(struct tmio_mmc_host *host)
struct sh_mobile_sdhi *priv = host_to_priv(host);
clk_disable_unprepare(priv->clk);
clk_disable_unprepare(priv->clk_cd);
}
static int sh_mobile_sdhi_card_busy(struct mmc_host *mmc)
@ -572,6 +580,21 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
goto eprobe;
}
/*
* Some controllers provide a 2nd clock just to run the internal card
* detection logic. Unfortunately, the existing driver architecture does
* not support a separation of clocks for runtime PM usage. When
* native hotplug is used, the tmio driver assumes that the core
* must continue to run for card detect to stay active, so we cannot
* disable it.
* Additionally, it is prohibited to supply a clock to the core but not
* to the card detect circuit. That leaves us with if separate clocks
* are presented, we must treat them both as virtually 1 clock.
*/
priv->clk_cd = devm_clk_get(&pdev->dev, "cd");
if (IS_ERR(priv->clk_cd))
priv->clk_cd = NULL;
priv->pinctrl = devm_pinctrl_get(&pdev->dev);
if (!IS_ERR(priv->pinctrl)) {
priv->pins_default = pinctrl_lookup_state(priv->pinctrl,