Commit 9dfd3381 authored by Mark Brown's avatar Mark Brown Committed by Samuel Ortiz
Browse files

mfd: Use bulk read to fill WM8350 register cache 



Some I2C controllers have high overheads for setting up I2C operations
which makes the register cache setup on startup excessively slow since
it does a lot of small transactions. Reduce this overhead by doing a
bulk read of the entire register bank and filtering out what we don't
need later.

Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@openedhand.com>
parent 22e2df7d

drivers/mfd/wm8350-core.c

+12 −9
Original line number Original line Diff line number Diff line
@@ -1238,7 +1238,7 @@ static int wm8350_create_cache(struct wm8350 *wm8350, int type, int mode) 
	}

	}





	wm8350->reg_cache =

	wm8350->reg_cache =

	    kzalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);

		kmalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);

	if (wm8350->reg_cache == NULL)

	if (wm8350->reg_cache == NULL)

		return -ENOMEM;

		return -ENOMEM;
@@ -1246,17 +1246,20 @@ static int wm8350_create_cache(struct wm8350 *wm8350, int type, int mode) 
	 * a PMIC so the device many not be in a virgin state and we

	 * a PMIC so the device many not be in a virgin state and we

	 * can't rely on the silicon values.

	 * can't rely on the silicon values.

	 */

	 */

	for (i = 0; i < WM8350_MAX_REGISTER; i++) {

	ret = wm8350->read_dev(wm8350, 0,

		/* audio register range */

			       sizeof(u16) * (WM8350_MAX_REGISTER + 1),

		if (wm8350_reg_io_map[i].readable &&

			       wm8350->reg_cache);

		    (i < WM8350_CLOCK_CONTROL_1 || i > WM8350_AIF_TEST)) {

			ret = wm8350->read_dev(wm8350, i, 2, (char *)&value);

	if (ret < 0) {

	if (ret < 0) {

		dev_err(wm8350->dev,

		dev_err(wm8350->dev,

				       "failed to read initial cache value\n");

			"failed to read initial cache values\n");

		goto out;

		goto out;

	}

	}

			value = be16_to_cpu(value);



	/* Mask out uncacheable/unreadable bits and the audio. */

	for (i = 0; i < WM8350_MAX_REGISTER; i++) {

		if (wm8350_reg_io_map[i].readable &&

		    (i < WM8350_CLOCK_CONTROL_1 || i > WM8350_AIF_TEST)) {

			value = be16_to_cpu(wm8350->reg_cache[i]);

			value &= wm8350_reg_io_map[i].readable;

			value &= wm8350_reg_io_map[i].readable;

			value &= ~wm8350_reg_io_map[i].vol;

			value &= ~wm8350_reg_io_map[i].vol;

			wm8350->reg_cache[i] = value;

			wm8350->reg_cache[i] = value;

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