Commit 67488526 authored by Mark Brown's avatar Mark Brown Committed by Samuel Ortiz
Browse files

mfd: Add AUXADC support for WM8350 



The auxiliary ADC in the WM8350 is shared between several subdevices
so access to it needs to be arbitrated by the core driver.

Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@openedhand.com>
parent 0c8a6016

drivers/mfd/wm8350-core.c

+50 −1
Original line number Diff line number Diff line
@@ -63,7 +63,6 @@ 
 */

static DEFINE_MUTEX(io_mutex);

static DEFINE_MUTEX(reg_lock_mutex);

static DEFINE_MUTEX(auxadc_mutex);



/* Perform a physical read from the device.

 */
@@ -1082,6 +1081,55 @@ int wm8350_unmask_irq(struct wm8350 *wm8350, int irq) 
}

EXPORT_SYMBOL_GPL(wm8350_unmask_irq);



int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)

{

	u16 reg, result = 0;

	int tries = 5;



	if (channel < WM8350_AUXADC_AUX1 || channel > WM8350_AUXADC_TEMP)

		return -EINVAL;

	if (channel >= WM8350_AUXADC_USB && channel <= WM8350_AUXADC_TEMP

	    && (scale != 0 || vref != 0))

		return -EINVAL;



	mutex_lock(&wm8350->auxadc_mutex);



	/* Turn on the ADC */

	reg = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);

	wm8350_reg_write(wm8350, WM8350_POWER_MGMT_5, reg | WM8350_AUXADC_ENA);



	if (scale || vref) {

		reg = scale << 13;

		reg |= vref << 12;

		wm8350_reg_write(wm8350, WM8350_AUX1_READBACK + channel, reg);

	}



	reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);

	reg |= 1 << channel | WM8350_AUXADC_POLL;

	wm8350_reg_write(wm8350, WM8350_DIGITISER_CONTROL_1, reg);



	do {

		schedule_timeout_interruptible(1);

		reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);

	} while (tries-- && (reg & WM8350_AUXADC_POLL));



	if (!tries)

		dev_err(wm8350->dev, "adc chn %d read timeout\n", channel);

	else

		result = wm8350_reg_read(wm8350,

					 WM8350_AUX1_READBACK + channel);



	/* Turn off the ADC */

	reg = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);

	wm8350_reg_write(wm8350, WM8350_POWER_MGMT_5,

			 reg & ~WM8350_AUXADC_ENA);



	mutex_unlock(&wm8350->auxadc_mutex);



	return result & WM8350_AUXADC_DATA1_MASK;

}

EXPORT_SYMBOL_GPL(wm8350_read_auxadc);



/*

 * Cache is always host endian.

 */
@@ -1239,6 +1287,7 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq, 
		}

	}



	mutex_init(&wm8350->auxadc_mutex);

	mutex_init(&wm8350->irq_mutex);

	INIT_WORK(&wm8350->irq_work, wm8350_irq_worker);

	if (irq) {

include/linux/mfd/wm8350/comparator.h

+8 −0
Original line number Diff line number Diff line
@@ -164,4 +164,12 @@ 
#define WM8350_AUXADC_BATT			6

#define WM8350_AUXADC_TEMP			7



struct wm8350;



/*

 * AUX ADC Readback

 */

int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale,

		       int vref);



#endif

include/linux/mfd/wm8350/core.h

+2 −0
Original line number Diff line number Diff line
@@ -573,6 +573,8 @@ struct wm8350 { 
			 void *src);

	u16 *reg_cache;



	struct mutex auxadc_mutex;



	/* Interrupt handling */

	struct work_struct irq_work;

	struct mutex irq_mutex; /* IRQ table mutex */