[media] rtl2832: add muxed I2C adapter for demod itself

There was a deadlock between master I2C adapter and muxed I2C
adapter. Implement two I2C muxed I2C adapters and leave master
alone, just only for offering I2C adapter for these mux adapters.

Reported-by: Luis Alves <ljalvs@gmail.com>
Reported-by: Benjamin Larsson <benjamin@southpole.se>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 57 insertions, 14 deletions

diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index dc46cf0841e0..c0366a8640c7 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -180,7 +180,7 @@ static int rtl2832_wr(struct rtl2832_priv *priv, u8 reg, u8 *val, int len)
         buf[0] = reg;
         memcpy(&buf[1], val, len);
 
-        ret = i2c_transfer(priv->i2c, msg, 1);
+        ret = i2c_transfer(priv->i2c_adapter, msg, 1);
         if (ret == 1) {
                 ret = 0;
         } else {
@@ -210,7 +210,7 @@ static int rtl2832_rd(struct rtl2832_priv *priv, u8 reg, u8 *val, int len)
                 }
         };
 
-        ret = i2c_transfer(priv->i2c, msg, 2);
+        ret = i2c_transfer(priv->i2c_adapter, msg, 2);
         if (ret == 2) {
                 ret = 0;
         } else {
@@ -891,26 +891,61 @@ static void rtl2832_release(struct dvb_frontend *fe)
         struct rtl2832_priv *priv = fe->demodulator_priv;
 
         dev_dbg(&priv->i2c->dev, "%s:\n", __func__);
+        i2c_del_mux_adapter(priv->i2c_adapter_tuner);
         i2c_del_mux_adapter(priv->i2c_adapter);
         kfree(priv);
 }
 
-static int rtl2832_select(struct i2c_adapter *adap, void *mux_priv, u32 chan)
+static int rtl2832_select(struct i2c_adapter *adap, void *mux_priv, u32 chan_id)
 {
         struct rtl2832_priv *priv = mux_priv;
-        return rtl2832_i2c_gate_ctrl(&priv->fe, 1);
-}
+        int ret;
+        u8 buf[2];
+        struct i2c_msg msg[1] = {
+                {
+                        .addr = priv->cfg.i2c_addr,
+                        .flags = 0,
+                        .len = sizeof(buf),
+                        .buf = buf,
+                }
+        };
 
-static int rtl2832_deselect(struct i2c_adapter *adap, void *mux_priv, u32 chan)
-{
-        struct rtl2832_priv *priv = mux_priv;
-        return rtl2832_i2c_gate_ctrl(&priv->fe, 0);
+        if (priv->i2c_gate_state == chan_id)
+                return 0;
+
+        /* select reg bank 1 */
+        buf[0] = 0x00;
+        buf[1] = 0x01;
+
+        ret = i2c_transfer(adap, msg, 1);
+        if (ret != 1)
+                goto err;
+
+        priv->page = 1;
+
+        /* open or close I2C repeater gate */
+        buf[0] = 0x01;
+        if (chan_id == 1)
+                buf[1] = 0x18; /* open */
+        else
+                buf[1] = 0x10; /* close */
+
+        ret = i2c_transfer(adap, msg, 1);
+        if (ret != 1)
+                goto err;
+
+        priv->i2c_gate_state = chan_id;
+
+        return 0;
+err:
+        dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
+        return -EREMOTEIO;
 }
 
 struct i2c_adapter *rtl2832_get_i2c_adapter(struct dvb_frontend *fe)
 {
         struct rtl2832_priv *priv = fe->demodulator_priv;
-        return priv->i2c_adapter;
+        return priv->i2c_adapter_tuner;
 }
 EXPORT_SYMBOL(rtl2832_get_i2c_adapter);
 
@@ -933,15 +968,21 @@ struct dvb_frontend *rtl2832_attach(const struct rtl2832_config *cfg,
         priv->tuner = cfg->tuner;
         memcpy(&priv->cfg, cfg, sizeof(struct rtl2832_config));
 
+        /* create muxed i2c adapter for demod itself */
+        priv->i2c_adapter = i2c_add_mux_adapter(i2c, &i2c->dev, priv, 0, 0, 0,
+                        rtl2832_select, NULL);
+        if (priv->i2c_adapter == NULL)
+                goto err;
+
         /* check if the demod is there */
         ret = rtl2832_rd_reg(priv, 0x00, 0x0, &tmp);
         if (ret)
                 goto err;
 
-        /* create muxed i2c adapter */
-        priv->i2c_adapter = i2c_add_mux_adapter(i2c, &i2c->dev, priv, 0, 0, 0,
-                        rtl2832_select, rtl2832_deselect);
-        if (priv->i2c_adapter == NULL)
+        /* create muxed i2c adapter for demod tuner bus */
+        priv->i2c_adapter_tuner = i2c_add_mux_adapter(i2c, &i2c->dev, priv,
+                        0, 1, 0, rtl2832_select, NULL);
+        if (priv->i2c_adapter_tuner == NULL)
                 goto err;
 
         /* create dvb_frontend */
@@ -954,6 +995,8 @@ struct dvb_frontend *rtl2832_attach(const struct rtl2832_config *cfg,
         return &priv->fe;
 err:
         dev_dbg(&i2c->dev, "%s: failed=%d\n", __func__, ret);
+        if (priv && priv->i2c_adapter)
+                i2c_del_mux_adapter(priv->i2c_adapter);
         kfree(priv);
         return NULL;
 }