mfd: Add AUXADC support for WM8350

[safe/jmp/linux-2.6] / drivers / mfd / wm8350-core.c

diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index c013afd..60439bd 100644 (file)
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -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) {