ASoC: wm2000: Integrate with clock API

Request MCLK as a clock and then enable it when carrying out a state
transtion and while ANC is active, minimising system power consumption
in idle modes.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/sound/soc/codecs/wm2000.c b/sound/soc/codecs/wm2000.c
index 1cbe88f01d63..0aba8ce424ca 100644
--- a/sound/soc/codecs/wm2000.c
+++ b/sound/soc/codecs/wm2000.c
@@ -26,6 +26,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/firmware.h>
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/pm.h>
 #include <linux/i2c.h>
@@ -62,6 +63,7 @@ enum wm2000_anc_mode {
 struct wm2000_priv {
         struct i2c_client *i2c;
         struct regmap *regmap;
+        struct clk *mclk;
 
         struct regulator_bulk_data supplies[WM2000_NUM_SUPPLIES];
 
@@ -550,6 +552,15 @@ static int wm2000_anc_transition(struct wm2000_priv *wm2000,
                 return -EINVAL;
         }
 
+        /* Maintain clock while active */
+        if (anc_transitions[i].source == ANC_OFF) {
+                ret = clk_prepare_enable(wm2000->mclk);
+                if (ret != 0) {
+                        dev_err(&i2c->dev, "Failed to enable MCLK: %d\n", ret);
+                        return ret;
+                }
+        }
+
         for (j = 0; j < ARRAY_SIZE(anc_transitions[j].step); j++) {
                 if (!anc_transitions[i].step[j])
                         break;
@@ -559,7 +570,10 @@ static int wm2000_anc_transition(struct wm2000_priv *wm2000,
                         return ret;
         }
 
-        return 0;
+        if (anc_transitions[i].dest == ANC_OFF)
+                clk_disable_unprepare(wm2000->mclk);
+
+        return ret;
 }
 
 static int wm2000_anc_set_mode(struct wm2000_priv *wm2000)
@@ -823,6 +837,13 @@ static int wm2000_i2c_probe(struct i2c_client *i2c,
         reg = wm2000_read(i2c, WM2000_REG_REVISON);
         dev_info(&i2c->dev, "revision %c\n", reg + 'A');
 
+        wm2000->mclk = devm_clk_get(&i2c->dev, "MCLK");
+        if (IS_ERR(wm2000->mclk)) {
+                ret = PTR_ERR(wm2000->mclk);
+                dev_err(&i2c->dev, "Failed to get MCLK: %d\n", ret);
+                goto err_supplies;
+        }
+
         filename = "wm2000_anc.bin";
         pdata = dev_get_platdata(&i2c->dev);
         if (pdata) {