Commit fd4cfa8b authored by Antti Palosaari's avatar Antti Palosaari Committed by Mauro Carvalho Chehab
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[media] rtl2830: implement own I2C locking 



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: default avatarAntti Palosaari <crope@iki.fi>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent d9bd3fa6

drivers/media/dvb-frontends/rtl2830.c

+38 −7
Original line number Diff line number Diff line
@@ -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;

drivers/media/dvb-frontends/rtl2830_priv.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

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