1 files changed, 101 insertions, 0 deletions

diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
index eb63d22160d1..42bef1dd2ca1 100644
--- a/drivers/mfd/wm831x-core.c
+++ b/drivers/mfd/wm831x-core.c
@@ -15,11 +15,14 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/delay.h>
 #include <linux/mfd/core.h>
 
 #include <linux/mfd/wm831x/core.h>
 #include <linux/mfd/wm831x/pdata.h>
 #include <linux/mfd/wm831x/irq.h>
+#include <linux/mfd/wm831x/auxadc.h>
 
 enum wm831x_parent {
         WM8310 = 0,
@@ -244,6 +247,103 @@ out:
 }
 EXPORT_SYMBOL_GPL(wm831x_set_bits);
 
+/**
+ * wm831x_auxadc_read: Read a value from the WM831x AUXADC
+ *
+ * @wm831x: Device to read from.
+ * @input: AUXADC input to read.
+ */
+int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
+{
+        int tries = 10;
+        int ret, src;
+
+        mutex_lock(&wm831x->auxadc_lock);
+
+        ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
+                              WM831X_AUX_ENA, WM831X_AUX_ENA);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
+                goto out;
+        }
+
+        /* We force a single source at present */
+        src = input;
+        ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
+                               1 << src);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
+                goto out;
+        }
+
+        ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
+                              WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
+                goto disable;
+        }
+
+        do {
+                msleep(1);
+
+                ret = wm831x_reg_read(wm831x, WM831X_AUXADC_CONTROL);
+                if (ret < 0)
+                        ret = WM831X_AUX_CVT_ENA;
+        } while ((ret & WM831X_AUX_CVT_ENA) && --tries);
+
+        if (ret & WM831X_AUX_CVT_ENA) {
+                dev_err(wm831x->dev, "Timed out reading AUXADC\n");
+                ret = -EBUSY;
+                goto disable;
+        }
+
+        ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to read AUXADC data: %d\n", ret);
+        } else {
+                src = ((ret & WM831X_AUX_DATA_SRC_MASK)
+                       >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
+
+                if (src == 14)
+                        src = WM831X_AUX_CAL;
+
+                if (src != input) {
+                        dev_err(wm831x->dev, "Data from source %d not %d\n",
+                                src, input);
+                        ret = -EINVAL;
+                } else {
+                        ret &= WM831X_AUX_DATA_MASK;
+                }
+        }
+
+disable:
+        wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
+out:
+        mutex_unlock(&wm831x->auxadc_lock);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
+
+/**
+ * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
+ *
+ * @wm831x: Device to read from.
+ * @input: AUXADC input to read.
+ */
+int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
+{
+        int ret;
+
+        ret = wm831x_auxadc_read(wm831x, input);
+        if (ret < 0)
+                return ret;
+
+        ret *= 1465;
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
+
 static struct resource wm831x_dcdc1_resources[] = {
         {
                 .start = WM831X_DC1_CONTROL_1,
@@ -1084,6 +1184,7 @@ static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
 
         mutex_init(&wm831x->io_lock);
         mutex_init(&wm831x->key_lock);
+        mutex_init(&wm831x->auxadc_lock);
         dev_set_drvdata(wm831x->dev, wm831x);
 
         ret = wm831x_reg_read(wm831x, WM831X_PARENT_ID);