[media] fc0012: rework attach() to check chip id and I/O errors

Signed-off-by: Antti Palosaari <crope@iki.fi>
Acked-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 49 insertions, 10 deletions

diff --git a/drivers/media/tuners/fc0012.c b/drivers/media/tuners/fc0012.c
index 01f5e406282c..feb15941cc5b 100644
--- a/drivers/media/tuners/fc0012.c
+++ b/drivers/media/tuners/fc0012.c
@@ -443,32 +443,71 @@ static const struct dvb_tuner_ops fc0012_tuner_ops = {
 struct dvb_frontend *fc0012_attach(struct dvb_frontend *fe,
         struct i2c_adapter *i2c, const struct fc0012_config *cfg)
 {
-        struct fc0012_priv *priv = NULL;
+        struct fc0012_priv *priv;
+        int ret;
+        u8 chip_id;
+
+        if (fe->ops.i2c_gate_ctrl)
+                fe->ops.i2c_gate_ctrl(fe, 1);
 
         priv = kzalloc(sizeof(struct fc0012_priv), GFP_KERNEL);
-        if (priv == NULL)
-                return NULL;
+        if (!priv) {
+                ret = -ENOMEM;
+                dev_err(&i2c->dev, "%s: kzalloc() failed\n", KBUILD_MODNAME);
+                goto err;
+        }
 
-        priv->i2c = i2c;
         priv->cfg = cfg;
+        priv->i2c = i2c;
 
-        info("Fitipower FC0012 successfully attached.");
+        /* check if the tuner is there */
+        ret = fc0012_readreg(priv, 0x00, &chip_id);
+        if (ret < 0)
+                goto err;
 
-        fe->tuner_priv = priv;
+        dev_dbg(&i2c->dev, "%s: chip_id=%02x\n", __func__, chip_id);
 
-        if (priv->cfg->loop_through)
-                fc0012_writereg(priv, 0x09, 0x6f);
+        switch (chip_id) {
+        case 0xa1:
+                break;
+        default:
+                ret = -ENODEV;
+                goto err;
+        }
+
+        dev_info(&i2c->dev, "%s: Fitipower FC0012 successfully identified\n",
+                        KBUILD_MODNAME);
+
+        if (priv->cfg->loop_through) {
+                ret = fc0012_writereg(priv, 0x09, 0x6f);
+                if (ret < 0)
+                        goto err;
+        }
 
         /*
          * TODO: Clock out en or div?
          * For dual tuner configuration clearing bit [0] is required.
          */
-        if (priv->cfg->clock_out)
-                fc0012_writereg(priv, 0x0b, 0x82);
+        if (priv->cfg->clock_out) {
+                ret =  fc0012_writereg(priv, 0x0b, 0x82);
+                if (ret < 0)
+                        goto err;
+        }
 
+        fe->tuner_priv = priv;
         memcpy(&fe->ops.tuner_ops, &fc0012_tuner_ops,
                 sizeof(struct dvb_tuner_ops));
 
+err:
+        if (fe->ops.i2c_gate_ctrl)
+                fe->ops.i2c_gate_ctrl(fe, 0);
+
+        if (ret) {
+                dev_dbg(&i2c->dev, "%s: failed: %d\n", __func__, ret);
+                kfree(priv);
+                return NULL;
+        }
+
         return fe;
 }
 EXPORT_SYMBOL(fc0012_attach);