From fd4cfa8bb1bc0cdd385f33303b5058674ea8e24c Mon Sep 17 00:00:00 2001 From: Antti Palosaari Date: Tue, 9 Dec 2014 16:14:41 -0300 Subject: [PATCH] [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: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/rtl2830.c | 45 ++++++++++++++++++---- drivers/media/dvb-frontends/rtl2830_priv.h | 1 + 2 files changed, 39 insertions(+), 7 deletions(-) diff --git a/drivers/media/dvb-frontends/rtl2830.c b/drivers/media/dvb-frontends/rtl2830.c index 8abaca66e132..3a9e4e986fc2 100644 --- a/drivers/media/dvb-frontends/rtl2830.c +++ b/drivers/media/dvb-frontends/rtl2830.c @@ -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; diff --git a/drivers/media/dvb-frontends/rtl2830_priv.h b/drivers/media/dvb-frontends/rtl2830_priv.h index 293188924f51..517758ab687a 100644 --- a/drivers/media/dvb-frontends/rtl2830_priv.h +++ b/drivers/media/dvb-frontends/rtl2830_priv.h @@ -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; -- 2.20.1