redonkable/remarkable-linux
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[media] rtl2830: implement own I2C locking

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Own I2C locking is needed due to two special reasons:
1) Chips uses multiple register pages/banks on single I2C slave.
Page is changed via I2C register access.
2) Chip offers muxed/gated I2C adapter for tuner. Gate/mux is
controlled by I2C register access.

Due to these reasons, I2C locking did not fit very well.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Antti Palosaari 2014-12-09 16:14:41 -03:00 committed by Mauro Carvalho Chehab
parent d9bd3fa6ec
commit fd4cfa8bb1
2 changed files with 39 additions and 7 deletions
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45
drivers/media/dvb-frontends/rtl2830.c
View file

@ -43,7 +43,7 @@ static int rtl2830_wr(struct i2c_client *client, u8 reg, const u8 *val, int len)
buf[0] = reg;
memcpy(&buf[1], val, len);
ret = i2c_transfer(client->adapter, msg, 1);
ret = __i2c_transfer(client->adapter, msg, 1);
if (ret == 1) {
ret = 0;
} else {
@ -73,7 +73,7 @@ static int rtl2830_rd(struct i2c_client *client, u8 reg, u8 *val, int len)
}
};
ret = i2c_transfer(client->adapter, msg, 2);
ret = __i2c_transfer(client->adapter, msg, 2);
if (ret == 2) {
ret = 0;
} else {
@ -93,16 +93,23 @@ static int rtl2830_wr_regs(struct i2c_client *client, u16 reg, const u8 *val, in
u8 reg2 = (reg >> 0) & 0xff;
u8 page = (reg >> 8) & 0xff;
mutex_lock(&dev->i2c_mutex);
/* switch bank if needed */
if (page != dev->page) {
ret = rtl2830_wr(client, 0x00, &page, 1);
if (ret)
return ret;
goto err_mutex_unlock;
dev->page = page;
}
return rtl2830_wr(client, reg2, val, len);
ret = rtl2830_wr(client, reg2, val, len);
err_mutex_unlock:
mutex_unlock(&dev->i2c_mutex);
return ret;
}
/* read multiple registers */
@ -113,16 +120,23 @@ static int rtl2830_rd_regs(struct i2c_client *client, u16 reg, u8 *val, int len)
u8 reg2 = (reg >> 0) & 0xff;
u8 page = (reg >> 8) & 0xff;
mutex_lock(&dev->i2c_mutex);
/* switch bank if needed */
if (page != dev->page) {
ret = rtl2830_wr(client, 0x00, &page, 1);
if (ret)
return ret;
goto err_mutex_unlock;
dev->page = page;
}
return rtl2830_rd(client, reg2, val, len);
ret = rtl2830_rd(client, reg2, val, len);
err_mutex_unlock:
mutex_unlock(&dev->i2c_mutex);
return ret;
}
/* read single register */
@ -815,6 +829,10 @@ static int rtl2830_select(struct i2c_adapter *adap, void *mux_priv, u32 chan_id)
};
int ret;
dev_dbg(&client->dev, "\n");
mutex_lock(&dev->i2c_mutex);
/* select register page */
ret = __i2c_transfer(client->adapter, select_reg_page_msg, 1);
if (ret != 1) {
@ -841,6 +859,18 @@ err:
return ret;
}
static int rtl2830_deselect(struct i2c_adapter *adap, void *mux_priv, u32 chan)
{
struct i2c_client *client = mux_priv;
struct rtl2830_dev *dev = i2c_get_clientdata(client);
dev_dbg(&client->dev, "\n");
mutex_unlock(&dev->i2c_mutex);
return 0;
}
static struct dvb_frontend *rtl2830_get_dvb_frontend(struct i2c_client *client)
{
struct rtl2830_dev *dev = i2c_get_clientdata(client);
@ -886,6 +916,7 @@ static int rtl2830_probe(struct i2c_client *client,
dev->client = client;
dev->pdata = client->dev.platform_data;
dev->sleeping = true;
mutex_init(&dev->i2c_mutex);
INIT_DELAYED_WORK(&dev->stat_work, rtl2830_stat_work);
/* check if the demod is there */
@ -895,7 +926,7 @@ static int rtl2830_probe(struct i2c_client *client,
/* create muxed i2c adapter for tuner */
dev->adapter = i2c_add_mux_adapter(client->adapter, &client->dev,
client, 0, 0, 0, rtl2830_select, NULL);
client, 0, 0, 0, rtl2830_select, rtl2830_deselect);
if (dev->adapter == NULL) {
ret = -ENODEV;
goto err_kfree;

1
drivers/media/dvb-frontends/rtl2830_priv.h
View file

@ -30,6 +30,7 @@ struct rtl2830_dev {
struct i2c_adapter *adapter;
struct dvb_frontend fe;
bool sleeping;
struct mutex i2c_mutex;
u8 page; /* active register page */
unsigned long filters;
struct delayed_work stat_work;