[media] m88ds3103: use I2C mux for tuner I2C adapter

Switch standard I2C adapter to muxed I2C adapter.

David reported that I2C adapter implementation caused deadlock.
I discussed with Jean and he suggested to implement it as a
multiplexed i2c adapter because tuner I2C bus could be seen like
own I2C segment.

Reported-by: David Howells <dhowells@redhat.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/dvb-frontends/Kconfig b/drivers/media/dvb-frontends/Kconfig
index 6c46caf..dd12a1e 100644 (file)
--- a/drivers/media/dvb-frontends/Kconfig
+++ b/drivers/media/dvb-frontends/Kconfig
@@ -37,7 +37,7 @@ config DVB_STV6110x
 
 config DVB_M88DS3103
        tristate "Montage M88DS3103"
-       depends on DVB_CORE && I2C
+       depends on DVB_CORE && I2C && I2C_MUX
        default m if !MEDIA_SUBDRV_AUTOSELECT
        help
          Say Y when you want to support this frontend.

diff --git a/drivers/media/dvb-frontends/m88ds3103.c b/drivers/media/dvb-frontends/m88ds3103.c
index 302c923..e07e8d6 100644 (file)
--- a/drivers/media/dvb-frontends/m88ds3103.c
+++ b/drivers/media/dvb-frontends/m88ds3103.c
@@ -1108,15 +1108,16 @@ static int m88ds3103_get_tune_settings(struct dvb_frontend *fe,
        return 0;
 }
 
-static u32 m88ds3103_tuner_i2c_func(struct i2c_adapter *adapter)
+static void m88ds3103_release(struct dvb_frontend *fe)
 {
-       return I2C_FUNC_I2C;
+       struct m88ds3103_priv *priv = fe->demodulator_priv;
+       i2c_del_mux_adapter(priv->i2c_adapter);
+       kfree(priv);
 }
 
-static int m88ds3103_tuner_i2c_xfer(struct i2c_adapter *i2c_adap,
-               struct i2c_msg msg[], int num)
+static int m88ds3103_select(struct i2c_adapter *adap, void *mux_priv, u32 chan)
 {
-       struct m88ds3103_priv *priv = i2c_get_adapdata(i2c_adap);
+       struct m88ds3103_priv *priv = mux_priv;
        int ret;
        struct i2c_msg gate_open_msg[1] = {
                {
@@ -1126,43 +1127,31 @@ static int m88ds3103_tuner_i2c_xfer(struct i2c_adapter *i2c_adap,
                        .buf = "\x03\x11",
                }
        };
-       dev_dbg(&priv->i2c->dev, "%s: num=%d\n", __func__, num);
 
        mutex_lock(&priv->i2c_mutex);
 
-       /* open i2c-gate */
+       /* open tuner I2C repeater for 1 xfer, closes automatically */
        ret = i2c_transfer(priv->i2c, gate_open_msg, 1);
        if (ret != 1) {
-               mutex_unlock(&priv->i2c_mutex);
-               dev_warn(&priv->i2c->dev,
-                               "%s: i2c wr failed=%d\n",
+               dev_warn(&priv->i2c->dev, "%s: i2c wr failed=%d\n",
                                KBUILD_MODNAME, ret);
-               ret = -EREMOTEIO;
-               goto err;
-       }
+               if (ret >= 0)
+                       ret = -EREMOTEIO;
 
-       ret = i2c_transfer(priv->i2c, msg, num);
-       mutex_unlock(&priv->i2c_mutex);
-       if (ret < 0)
-               dev_warn(&priv->i2c->dev, "%s: i2c failed=%d\n",
-                               KBUILD_MODNAME, ret);
+               return ret;
+       }
 
-       return ret;
-err:
-       dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
-       return ret;
+       return 0;
 }
 
-static struct i2c_algorithm m88ds3103_tuner_i2c_algo = {
-       .master_xfer   = m88ds3103_tuner_i2c_xfer,
-       .functionality = m88ds3103_tuner_i2c_func,
-};
-
-static void m88ds3103_release(struct dvb_frontend *fe)
+static int m88ds3103_deselect(struct i2c_adapter *adap, void *mux_priv,
+               u32 chan)
 {
-       struct m88ds3103_priv *priv = fe->demodulator_priv;
-       i2c_del_adapter(&priv->i2c_adapter);
-       kfree(priv);
+       struct m88ds3103_priv *priv = mux_priv;
+
+       mutex_unlock(&priv->i2c_mutex);
+
+       return 0;
 }
 
 struct dvb_frontend *m88ds3103_attach(const struct m88ds3103_config *cfg,
@@ -1228,24 +1217,18 @@ struct dvb_frontend *m88ds3103_attach(const struct m88ds3103_config *cfg,
        if (ret)
                goto err;
 
+       /* create mux i2c adapter for tuner */
+       priv->i2c_adapter = i2c_add_mux_adapter(i2c, &i2c->dev, priv, 0, 0, 0,
+                       m88ds3103_select, m88ds3103_deselect);
+       if (priv->i2c_adapter == NULL)
+               goto err;
+
+       *tuner_i2c_adapter = priv->i2c_adapter;
+
        /* create dvb_frontend */
        memcpy(&priv->fe.ops, &m88ds3103_ops, sizeof(struct dvb_frontend_ops));
        priv->fe.demodulator_priv = priv;
 
-       /* create i2c adapter for tuner */
-       strlcpy(priv->i2c_adapter.name, KBUILD_MODNAME,
-                       sizeof(priv->i2c_adapter.name));
-       priv->i2c_adapter.algo = &m88ds3103_tuner_i2c_algo;
-       priv->i2c_adapter.algo_data = NULL;
-       i2c_set_adapdata(&priv->i2c_adapter, priv);
-       ret = i2c_add_adapter(&priv->i2c_adapter);
-       if (ret) {
-               dev_err(&i2c->dev, "%s: i2c bus could not be initialized\n",
-                               KBUILD_MODNAME);
-               goto err;
-       }
-       *tuner_i2c_adapter = &priv->i2c_adapter;
-
        return &priv->fe;
 err:
        dev_dbg(&i2c->dev, "%s: failed=%d\n", __func__, ret);

diff --git a/drivers/media/dvb-frontends/m88ds3103_priv.h b/drivers/media/dvb-frontends/m88ds3103_priv.h
index f3d0867..322db4d 100644 (file)
--- a/drivers/media/dvb-frontends/m88ds3103_priv.h
+++ b/drivers/media/dvb-frontends/m88ds3103_priv.h
@@ -25,6 +25,7 @@
 #include "m88ds3103.h"
 #include "dvb_math.h"
 #include <linux/firmware.h>
+#include <linux/i2c-mux.h>
 
 #define M88DS3103_FIRMWARE "dvb-demod-m88ds3103.fw"
 #define M88DS3103_MCLK_KHZ 96000
@@ -38,7 +39,7 @@ struct m88ds3103_priv {
        fe_delivery_system_t delivery_system;
        fe_status_t fe_status;
        bool warm; /* FW running */
-       struct i2c_adapter i2c_adapter;
+       struct i2c_adapter *i2c_adapter;
 };
 
 struct m88ds3103_reg_val {