mfd: Use completion interrupt for WM835x AUXADC

Use the completion interrupt generated by the device rather than
polling for conversions to complete. As a backup we still check
the state of the AUXADC if we don't get a completion, mostly for
systems that don't have the WM8350 interrupt infrastructure hooked
up.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 29 insertions, 6 deletions

diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index 9a970bd68775..bd75807d5302 100644
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -339,7 +339,6 @@ EXPORT_SYMBOL_GPL(wm8350_reg_unlock);
 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;
@@ -363,12 +362,13 @@ int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)
         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 ((reg & WM8350_AUXADC_POLL) && --tries);
+        /* We ignore the result of the completion and just check for a
+         * conversion result, allowing us to soldier on if the IRQ
+         * infrastructure is not set up for the chip. */
+        wait_for_completion_timeout(&wm8350->auxadc_done, msecs_to_jiffies(5));
 
-        if (!tries)
+        reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);
+        if (reg & WM8350_AUXADC_POLL)
                 dev_err(wm8350->dev, "adc chn %d read timeout\n", channel);
         else
                 result = wm8350_reg_read(wm8350,
@@ -385,6 +385,15 @@ int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)
 }
 EXPORT_SYMBOL_GPL(wm8350_read_auxadc);
 
+static irqreturn_t wm8350_auxadc_irq(int irq, void *irq_data)
+{
+        struct wm8350 *wm8350 = irq_data;
+
+        complete(&wm8350->auxadc_done);
+
+        return IRQ_HANDLED;
+}
+
 /*
  * Cache is always host endian.
  */
@@ -682,11 +691,22 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
         }
 
         mutex_init(&wm8350->auxadc_mutex);
+        init_completion(&wm8350->auxadc_done);
 
         ret = wm8350_irq_init(wm8350, irq, pdata);
         if (ret < 0)
                 goto err;
 
+        if (wm8350->irq_base) {
+                ret = request_threaded_irq(wm8350->irq_base +
+                                           WM8350_IRQ_AUXADC_DATARDY,
+                                           NULL, wm8350_auxadc_irq, 0,
+                                           "auxadc", wm8350);
+                if (ret < 0)
+                        dev_warn(wm8350->dev,
+                                 "Failed to request AUXADC IRQ: %d\n", ret);
+        }
+
         if (pdata && pdata->init) {
                 ret = pdata->init(wm8350);
                 if (ret != 0) {
@@ -736,6 +756,9 @@ void wm8350_device_exit(struct wm8350 *wm8350)
         platform_device_unregister(wm8350->gpio.pdev);
         platform_device_unregister(wm8350->codec.pdev);
 
+        if (wm8350->irq_base)
+                free_irq(wm8350->irq_base + WM8350_IRQ_AUXADC_DATARDY, wm8350);
+
         wm8350_irq_exit(wm8350);
 
         kfree(wm8350->reg_cache);