drm: tda998x: Protect the page register

As the HDMI registers of the TDA998x chips are accessed by pages,
the page register must be protected.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index d476279..6795f09 100644 (file)
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -32,6 +32,7 @@
 struct tda998x_priv {
        struct i2c_client *cec;
        struct i2c_client *hdmi;
+       struct mutex mutex;
        uint16_t rev;
        uint8_t current_page;
        int dpms;
@@ -402,9 +403,10 @@ reg_read_range(struct tda998x_priv *priv, uint16_t reg, char *buf, int cnt)
        uint8_t addr = REG2ADDR(reg);
        int ret;
 
+       mutex_lock(&priv->mutex);
        ret = set_page(priv, reg);
        if (ret < 0)
-               return ret;
+               goto out;
 
        ret = i2c_master_send(client, &addr, sizeof(addr));
        if (ret < 0)
@@ -414,10 +416,12 @@ reg_read_range(struct tda998x_priv *priv, uint16_t reg, char *buf, int cnt)
        if (ret < 0)
                goto fail;
 
-       return ret;
+       goto out;
 
 fail:
        dev_err(&client->dev, "Error %d reading from 0x%x\n", ret, reg);
+out:
+       mutex_unlock(&priv->mutex);
        return ret;
 }
 
@@ -431,13 +435,16 @@ reg_write_range(struct tda998x_priv *priv, uint16_t reg, uint8_t *p, int cnt)
        buf[0] = REG2ADDR(reg);
        memcpy(&buf[1], p, cnt);
 
+       mutex_lock(&priv->mutex);
        ret = set_page(priv, reg);
        if (ret < 0)
-               return;
+               goto out;
 
        ret = i2c_master_send(client, buf, cnt + 1);
        if (ret < 0)
                dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg);
+out:
+       mutex_unlock(&priv->mutex);
 }
 
 static int
@@ -459,13 +466,16 @@ reg_write(struct tda998x_priv *priv, uint16_t reg, uint8_t val)
        uint8_t buf[] = {REG2ADDR(reg), val};
        int ret;
 
+       mutex_lock(&priv->mutex);
        ret = set_page(priv, reg);
        if (ret < 0)
-               return;
+               goto out;
 
        ret = i2c_master_send(client, buf, sizeof(buf));
        if (ret < 0)
                dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg);
+out:
+       mutex_unlock(&priv->mutex);
 }
 
 static void
@@ -475,13 +485,16 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val)
        uint8_t buf[] = {REG2ADDR(reg), val >> 8, val};
        int ret;
 
+       mutex_lock(&priv->mutex);
        ret = set_page(priv, reg);
        if (ret < 0)
-               return;
+               goto out;
 
        ret = i2c_master_send(client, buf, sizeof(buf));
        if (ret < 0)
                dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg);
+out:
+       mutex_unlock(&priv->mutex);
 }
 
 static void
@@ -1268,6 +1281,8 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 
        priv->dpms = DRM_MODE_DPMS_OFF;
 
+       mutex_init(&priv->mutex);       /* protect the page access */
+
        /* wake up the device: */
        cec_write(priv, REG_CEC_ENAMODS,
                        CEC_ENAMODS_EN_RXSENS | CEC_ENAMODS_EN_HDMI);