Commit f90a0612 authored by Thomas Abraham's avatar Thomas Abraham Committed by Chris Ball
Browse files

mmc: dw_mmc: lookup for optional biu and ciu clocks 



Some platforms allow for clock gating and control of bus interface unit
clock and card interface unit clock. Add support for clock lookup of
optional biu and ciu clocks for clock gating and clock speed
determination.

Signed-off-by: default avatarAbhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: default avatarThomas Abraham <thomas.abraham@linaro.org>
Acked-by: default avatarWill Newton <will.newton@imgtec.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 1c2215b7

drivers/mmc/host/dw_mmc.c

+49 −3
Original line number Diff line number Diff line
@@ -1960,13 +1960,42 @@ int dw_mci_probe(struct dw_mci *host) 
		return -ENODEV;

	}



	if (!host->pdata->bus_hz) {

	host->biu_clk = clk_get(host->dev, "biu");

	if (IS_ERR(host->biu_clk)) {

		dev_dbg(host->dev, "biu clock not available\n");

	} else {

		ret = clk_prepare_enable(host->biu_clk);

		if (ret) {

			dev_err(host->dev, "failed to enable biu clock\n");

			clk_put(host->biu_clk);

			return ret;

		}

	}



	host->ciu_clk = clk_get(host->dev, "ciu");

	if (IS_ERR(host->ciu_clk)) {

		dev_dbg(host->dev, "ciu clock not available\n");

	} else {

		ret = clk_prepare_enable(host->ciu_clk);

		if (ret) {

			dev_err(host->dev, "failed to enable ciu clock\n");

			clk_put(host->ciu_clk);

			goto err_clk_biu;

		}

	}



	if (IS_ERR(host->ciu_clk))

		host->bus_hz = host->pdata->bus_hz;

	else

		host->bus_hz = clk_get_rate(host->ciu_clk);



	if (!host->bus_hz) {

		dev_err(host->dev,

			"Platform data must supply bus speed\n");

		return -ENODEV;

		ret = -ENODEV;

		goto err_clk_ciu;

	}



	host->bus_hz = host->pdata->bus_hz;

	host->quirks = host->pdata->quirks;



	spin_lock_init(&host->lock);
@@ -2116,6 +2145,17 @@ err_dmaunmap: 
		regulator_disable(host->vmmc);

		regulator_put(host->vmmc);

	}



err_clk_ciu:

	if (!IS_ERR(host->ciu_clk)) {

		clk_disable_unprepare(host->ciu_clk);

		clk_put(host->ciu_clk);

	}

err_clk_biu:

	if (!IS_ERR(host->biu_clk)) {

		clk_disable_unprepare(host->biu_clk);

		clk_put(host->biu_clk);

	}

	return ret;

}

EXPORT_SYMBOL(dw_mci_probe);
@@ -2149,6 +2189,12 @@ void dw_mci_remove(struct dw_mci *host) 
		regulator_put(host->vmmc);

	}



	if (!IS_ERR(host->ciu_clk))

		clk_disable_unprepare(host->ciu_clk);

	if (!IS_ERR(host->biu_clk))

		clk_disable_unprepare(host->biu_clk);

	clk_put(host->ciu_clk);

	clk_put(host->biu_clk);

}

EXPORT_SYMBOL(dw_mci_remove);

include/linux/mmc/dw_mmc.h

+4 −0
Original line number Diff line number Diff line
@@ -78,6 +78,8 @@ struct mmc_data; 
 * @data_offset: Set the offset of DATA register according to VERID.

 * @dev: Device associated with the MMC controller.

 * @pdata: Platform data associated with the MMC controller.

 * @biu_clk: Pointer to bus interface unit clock instance.

 * @ciu_clk: Pointer to card interface unit clock instance.

 * @slot: Slots sharing this MMC controller.

 * @fifo_depth: depth of FIFO.

 * @data_shift: log2 of FIFO item size.
@@ -158,6 +160,8 @@ struct dw_mci { 
	u16			data_offset;

	struct device		*dev;

	struct dw_mci_board	*pdata;

	struct clk		*biu_clk;

	struct clk		*ciu_clk;

	struct dw_mci_slot	*slot[MAX_MCI_SLOTS];



	/* FIFO push and pull */

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