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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
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+50 −1
Original line number Original line Diff line number Diff line
@@ -63,7 +63,6 @@
 */
 */
static DEFINE_MUTEX(io_mutex);
static DEFINE_MUTEX(io_mutex);
static DEFINE_MUTEX(reg_lock_mutex);
static DEFINE_MUTEX(reg_lock_mutex);
static DEFINE_MUTEX(auxadc_mutex);


/* Perform a physical read from the device.
/* 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);
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.
 * 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);
	mutex_init(&wm8350->irq_mutex);
	INIT_WORK(&wm8350->irq_work, wm8350_irq_worker);
	INIT_WORK(&wm8350->irq_work, wm8350_irq_worker);
	if (irq) {
	if (irq) {
+8 −0
Original line number Original line Diff line number Diff line
@@ -164,4 +164,12 @@
#define WM8350_AUXADC_BATT			6
#define WM8350_AUXADC_BATT			6
#define WM8350_AUXADC_TEMP			7
#define WM8350_AUXADC_TEMP			7


struct wm8350;

/*
 * AUX ADC Readback
 */
int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale,
		       int vref);

#endif
#endif
+2 −0
Original line number Original line Diff line number Diff line
@@ -573,6 +573,8 @@ struct wm8350 {
			 void *src);
			 void *src);
	u16 *reg_cache;
	u16 *reg_cache;


	struct mutex auxadc_mutex;

	/* Interrupt handling */
	/* Interrupt handling */
	struct work_struct irq_work;
	struct work_struct irq_work;
	struct mutex irq_mutex; /* IRQ table mutex */
	struct mutex irq_mutex; /* IRQ table mutex */