[media] rtl2832: use regmap reg cache

Enable regmap register cache in order to reduce IO.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index e59765fa8e7c..66f915dd24a6 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -986,6 +986,22 @@ static struct dvb_frontend_ops rtl2832_ops = {
         .read_ber = rtl2832_read_ber,
 };
 
+static bool rtl2832_volatile_reg(struct device *dev, unsigned int reg)
+{
+        switch (reg) {
+        case 0x305:
+        case 0x33c:
+        case 0x34e:
+        case 0x351:
+        case 0x40c ... 0x40d:
+                return true;
+        default:
+                break;
+        }
+
+        return false;
+}
+
 /*
  * We implement own I2C access routines for regmap in order to get manual access
  * to I2C adapter lock, which is needed for I2C mux adapter.
@@ -1240,9 +1256,11 @@ static int rtl2832_probe(struct i2c_client *client,
         static const struct regmap_config regmap_config = {
                 .reg_bits    =  8,
                 .val_bits    =  8,
+                .volatile_reg = rtl2832_volatile_reg,
                 .max_register = 5 * 0x100,
                 .ranges = regmap_range_cfg,
                 .num_ranges = ARRAY_SIZE(regmap_range_cfg),
+                .cache_type = REGCACHE_RBTREE,
         };
 
         dev_dbg(&client->dev, "\n");