[media] rtl2832: implement delayed I2C gate close

Delay possible I2C gate close a little bit in order to see if there is next message coming to tuner in a sequence. Also, export private muxed I2C adapter. That is aimed only for SDR extension module as SDR belongs to same RTL2832 physical I2C bus (it is physically property of RTL2832, whilst it is own kernel module). Signed-off-by: Antti Palosaari <crope@iki.fi> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
author: Antti Palosaari <crope@iki.fi> 2014-02-08 01:50:04 -0500
committer: Mauro Carvalho Chehab <m.chehab@samsung.com> 2014-03-05 13:41:18 -0500
commit: 92d20d9fd13a2616294dc804ba3bb78312b84850 (patch)
tree: c61bb8666a9dca9c0571d608b3cc947d3b5116ea /drivers/media/dvb-frontends/rtl2832.c
parent: 0db5c800aa460c9f3cb142d65b5893c47ddcecb8 (diff)
1 files changed, 89 insertions, 3 deletions
diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index cfc54388a15e..fdbed35c87fa 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -891,16 +891,65 @@ static void rtl2832_release(struct dvb_frontend *fe)
        struct rtl2832_priv *priv = fe->demodulator_priv;
        dev_dbg(&priv->i2c->dev, "%s:\n", __func__);
+        cancel_delayed_work_sync(&priv->i2c_gate_work);
        i2c_del_mux_adapter(priv->i2c_adapter_tuner);
        i2c_del_mux_adapter(priv->i2c_adapter);
        kfree(priv);
 }
+/*
+ * Delay mechanism to avoid unneeded I2C gate open / close. Gate close is
+ * delayed here a little bit in order to see if there is sequence of I2C
+ * messages sent to same I2C bus.
+ * We must use unlocked version of __i2c_transfer() in order to avoid deadlock
+ * as lock is already taken by calling muxed i2c_transfer().
+ */
+static void rtl2832_i2c_gate_work(struct work_struct *work)
+{
+        struct rtl2832_priv *priv = container_of(work,
+                        struct rtl2832_priv, i2c_gate_work.work);
+        struct i2c_adapter *adap = priv->i2c;
+        int ret;
+        u8 buf[2];
+        struct i2c_msg msg[1] = {
+                {
+                        .addr = priv->cfg.i2c_addr,
+                        .flags = 0,
+                        .len = sizeof(buf),
+                        .buf = buf,
+                }
+        };
+        /* select reg bank 1 */
+        buf[0] = 0x00;
+        buf[1] = 0x01;
+        ret = __i2c_transfer(adap, msg, 1);
+        if (ret != 1)
+                goto err;
+        priv->page = 1;
+        /* close I2C repeater gate */
+        buf[0] = 0x01;
+        buf[1] = 0x10;
+        ret = __i2c_transfer(adap, msg, 1);
+        if (ret != 1)
+                goto err;
+        priv->i2c_gate_state = 0;
+        return;
+err:
+        dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
+        return;
+}
 static int rtl2832_select(struct i2c_adapter *adap, void *mux_priv, u32 chan_id)
 {
        struct rtl2832_priv *priv = mux_priv;
        int ret;
-        u8 buf[2];
+        u8 buf[2], val;
        struct i2c_msg msg[1] = {
                {
                        .addr = priv->cfg.i2c_addr,
@@ -909,6 +958,22 @@ static int rtl2832_select(struct i2c_adapter *adap, void *mux_priv, u32 chan_id)
                        .buf = buf,
                }
        };
+        struct i2c_msg msg_rd[2] = {
+                {
+                        .addr = priv->cfg.i2c_addr,
+                        .flags = 0,
+                        .len = 1,
+                        .buf = "\x01",
+                }, {
+                        .addr = priv->cfg.i2c_addr,
+                        .flags = I2C_M_RD,
+                        .len = 1,
+                        .buf = &val,
+                }
+        };
+        /* terminate possible gate closing */
+        cancel_delayed_work_sync(&priv->i2c_gate_work);
        if (priv->i2c_gate_state == chan_id)
                return 0;
@@ -916,13 +981,17 @@ static int rtl2832_select(struct i2c_adapter *adap, void *mux_priv, u32 chan_id)
        /* select reg bank 1 */
        buf[0] = 0x00;
        buf[1] = 0x01;
        ret = __i2c_transfer(adap, msg, 1);
        if (ret != 1)
                goto err;
        priv->page = 1;
+        /* we must read that register, otherwise there will be errors */
+        ret = __i2c_transfer(adap, msg_rd, 2);
+        if (ret != 2)
+                goto err;
        /* open or close I2C repeater gate */
        buf[0] = 0x01;
        if (chan_id == 1)
@@ -939,9 +1008,18 @@ static int rtl2832_select(struct i2c_adapter *adap, void *mux_priv, u32 chan_id)
        return 0;
 err:
        dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
        return -EREMOTEIO;
 }
+static int rtl2832_deselect(struct i2c_adapter *adap, void *mux_priv,
+                u32 chan_id)
+{
+        struct rtl2832_priv *priv = mux_priv;
+        schedule_delayed_work(&priv->i2c_gate_work, usecs_to_jiffies(100));
+        return 0;
+}
 struct i2c_adapter *rtl2832_get_i2c_adapter(struct dvb_frontend *fe)
 {
        struct rtl2832_priv *priv = fe->demodulator_priv;
@@ -949,6 +1027,13 @@ struct i2c_adapter *rtl2832_get_i2c_adapter(struct dvb_frontend *fe)
 }
 EXPORT_SYMBOL(rtl2832_get_i2c_adapter);
+struct i2c_adapter *rtl2832_get_private_i2c_adapter(struct dvb_frontend *fe)
+{
+        struct rtl2832_priv *priv = fe->demodulator_priv;
+        return priv->i2c_adapter;
+}
+EXPORT_SYMBOL(rtl2832_get_private_i2c_adapter);
 struct dvb_frontend *rtl2832_attach(const struct rtl2832_config *cfg,
        struct i2c_adapter *i2c)
 {
@@ -967,6 +1052,7 @@ struct dvb_frontend *rtl2832_attach(const struct rtl2832_config *cfg,
        priv->i2c = i2c;
        priv->tuner = cfg->tuner;
        memcpy(&priv->cfg, cfg, sizeof(struct rtl2832_config));
+        INIT_DELAYED_WORK(&priv->i2c_gate_work, rtl2832_i2c_gate_work);
        /* create muxed i2c adapter for demod itself */
        priv->i2c_adapter = i2c_add_mux_adapter(i2c, &i2c->dev, priv, 0, 0, 0,
@@ -981,7 +1067,7 @@ struct dvb_frontend *rtl2832_attach(const struct rtl2832_config *cfg,
        /* create muxed i2c adapter for demod tuner bus */
        priv->i2c_adapter_tuner = i2c_add_mux_adapter(i2c, &i2c->dev, priv,
-                        0, 1, 0, rtl2832_select, NULL);
+                        0, 1, 0, rtl2832_select, rtl2832_deselect);
        if (priv->i2c_adapter_tuner == NULL)
                goto err;
author	Antti Palosaari <crope@iki.fi>	2014-02-08 01:50:04 -0500
committer	Mauro Carvalho Chehab <m.chehab@samsung.com>	2014-03-05 13:41:18 -0500
commit	92d20d9fd13a2616294dc804ba3bb78312b84850 (patch)
tree	c61bb8666a9dca9c0571d608b3cc947d3b5116ea /drivers/media/dvb-frontends/rtl2832.c
parent	0db5c800aa460c9f3cb142d65b5893c47ddcecb8 (diff)

diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c index cfc54388a15e..fdbed35c87fa 100644 --- a/drivers/media/dvb-frontends/rtl2832.c +++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -891,16 +891,65 @@ static void rtl2832_release(struct dvb_frontend *fe)
891	struct rtl2832_priv *priv = fe->demodulator_priv;	891	struct rtl2832_priv *priv = fe->demodulator_priv;
892		892
893	dev_dbg(&priv->i2c->dev, "%s:\n", __func__);	893	dev_dbg(&priv->i2c->dev, "%s:\n", __func__);
		894	cancel_delayed_work_sync(&priv->i2c_gate_work);
894	i2c_del_mux_adapter(priv->i2c_adapter_tuner);	895	i2c_del_mux_adapter(priv->i2c_adapter_tuner);
895	i2c_del_mux_adapter(priv->i2c_adapter);	896	i2c_del_mux_adapter(priv->i2c_adapter);
896	kfree(priv);	897	kfree(priv);
897	}	898	}
898		899
		900	/*
		901	* Delay mechanism to avoid unneeded I2C gate open / close. Gate close is
		902	* delayed here a little bit in order to see if there is sequence of I2C
		903	* messages sent to same I2C bus.
		904	* We must use unlocked version of __i2c_transfer() in order to avoid deadlock
		905	* as lock is already taken by calling muxed i2c_transfer().
		906	*/
		907	static void rtl2832_i2c_gate_work(struct work_struct *work)
		908	{
		909	struct rtl2832_priv *priv = container_of(work,
		910	struct rtl2832_priv, i2c_gate_work.work);
		911	struct i2c_adapter *adap = priv->i2c;
		912	int ret;
		913	u8 buf[2];
		914	struct i2c_msg msg[1] = {
		915	{
		916	.addr = priv->cfg.i2c_addr,
		917	.flags = 0,
		918	.len = sizeof(buf),
		919	.buf = buf,
		920	}
		921	};
		922
		923	/* select reg bank 1 */
		924	buf[0] = 0x00;
		925	buf[1] = 0x01;
		926	ret = __i2c_transfer(adap, msg, 1);
		927	if (ret != 1)
		928	goto err;
		929
		930	priv->page = 1;
		931
		932	/* close I2C repeater gate */
		933	buf[0] = 0x01;
		934	buf[1] = 0x10;
		935	ret = __i2c_transfer(adap, msg, 1);
		936	if (ret != 1)
		937	goto err;
		938
		939	priv->i2c_gate_state = 0;
		940
		941	return;
		942	err:
		943	dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
		944
		945	return;
		946	}
		947
899	static int rtl2832_select(struct i2c_adapter adap, void mux_priv, u32 chan_id)	948	static int rtl2832_select(struct i2c_adapter adap, void mux_priv, u32 chan_id)
900	{	949	{
901	struct rtl2832_priv *priv = mux_priv;	950	struct rtl2832_priv *priv = mux_priv;
902	int ret;	951	int ret;
903	u8 buf[2];	952	u8 buf[2], val;
904	struct i2c_msg msg[1] = {	953	struct i2c_msg msg[1] = {
905	{	954	{
906	.addr = priv->cfg.i2c_addr,	955	.addr = priv->cfg.i2c_addr,
@@ -909,6 +958,22 @@ static int rtl2832_select(struct i2c_adapter adap, void mux_priv, u32 chan_id)
909	.buf = buf,	958	.buf = buf,
910	}	959	}
911	};	960	};
		961	struct i2c_msg msg_rd[2] = {
		962	{
		963	.addr = priv->cfg.i2c_addr,
		964	.flags = 0,
		965	.len = 1,
		966	.buf = "\x01",
		967	}, {
		968	.addr = priv->cfg.i2c_addr,
		969	.flags = I2C_M_RD,
		970	.len = 1,
		971	.buf = &val,
		972	}
		973	};
		974
		975	/* terminate possible gate closing */
		976	cancel_delayed_work_sync(&priv->i2c_gate_work);
912		977
913	if (priv->i2c_gate_state == chan_id)	978	if (priv->i2c_gate_state == chan_id)
914	return 0;	979	return 0;
@@ -916,13 +981,17 @@ static int rtl2832_select(struct i2c_adapter adap, void mux_priv, u32 chan_id)
916	/* select reg bank 1 */	981	/* select reg bank 1 */
917	buf[0] = 0x00;	982	buf[0] = 0x00;
918	buf[1] = 0x01;	983	buf[1] = 0x01;
919
920	ret = __i2c_transfer(adap, msg, 1);	984	ret = __i2c_transfer(adap, msg, 1);
921	if (ret != 1)	985	if (ret != 1)
922	goto err;	986	goto err;
923		987
924	priv->page = 1;	988	priv->page = 1;
925		989
		990	/* we must read that register, otherwise there will be errors */
		991	ret = __i2c_transfer(adap, msg_rd, 2);
		992	if (ret != 2)
		993	goto err;
		994
926	/* open or close I2C repeater gate */	995	/* open or close I2C repeater gate */
927	buf[0] = 0x01;	996	buf[0] = 0x01;
928	if (chan_id == 1)	997	if (chan_id == 1)
@@ -939,9 +1008,18 @@ static int rtl2832_select(struct i2c_adapter adap, void mux_priv, u32 chan_id)
939	return 0;	1008	return 0;
940	err:	1009	err:
941	dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);	1010	dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
		1011
942	return -EREMOTEIO;	1012	return -EREMOTEIO;
943	}	1013	}
944		1014
		1015	static int rtl2832_deselect(struct i2c_adapter adap, void mux_priv,
		1016	u32 chan_id)
		1017	{
		1018	struct rtl2832_priv *priv = mux_priv;
		1019	schedule_delayed_work(&priv->i2c_gate_work, usecs_to_jiffies(100));
		1020	return 0;
		1021	}
		1022
945	struct i2c_adapter rtl2832_get_i2c_adapter(struct dvb_frontend fe)	1023	struct i2c_adapter rtl2832_get_i2c_adapter(struct dvb_frontend fe)
946	{	1024	{
947	struct rtl2832_priv *priv = fe->demodulator_priv;	1025	struct rtl2832_priv *priv = fe->demodulator_priv;
@@ -949,6 +1027,13 @@ struct i2c_adapter rtl2832_get_i2c_adapter(struct dvb_frontend fe)
949	}	1027	}
950	EXPORT_SYMBOL(rtl2832_get_i2c_adapter);	1028	EXPORT_SYMBOL(rtl2832_get_i2c_adapter);
951		1029
		1030	struct i2c_adapter rtl2832_get_private_i2c_adapter(struct dvb_frontend fe)
		1031	{
		1032	struct rtl2832_priv *priv = fe->demodulator_priv;
		1033	return priv->i2c_adapter;
		1034	}
		1035	EXPORT_SYMBOL(rtl2832_get_private_i2c_adapter);
		1036
952	struct dvb_frontend rtl2832_attach(const struct rtl2832_config cfg,	1037	struct dvb_frontend rtl2832_attach(const struct rtl2832_config cfg,
953	struct i2c_adapter *i2c)	1038	struct i2c_adapter *i2c)
954	{	1039	{
@@ -967,6 +1052,7 @@ struct dvb_frontend rtl2832_attach(const struct rtl2832_config cfg,
967	priv->i2c = i2c;	1052	priv->i2c = i2c;
968	priv->tuner = cfg->tuner;	1053	priv->tuner = cfg->tuner;
969	memcpy(&priv->cfg, cfg, sizeof(struct rtl2832_config));	1054	memcpy(&priv->cfg, cfg, sizeof(struct rtl2832_config));
		1055	INIT_DELAYED_WORK(&priv->i2c_gate_work, rtl2832_i2c_gate_work);
970		1056
971	/* create muxed i2c adapter for demod itself */	1057	/* create muxed i2c adapter for demod itself */
972	priv->i2c_adapter = i2c_add_mux_adapter(i2c, &i2c->dev, priv, 0, 0, 0,	1058	priv->i2c_adapter = i2c_add_mux_adapter(i2c, &i2c->dev, priv, 0, 0, 0,
@@ -981,7 +1067,7 @@ struct dvb_frontend rtl2832_attach(const struct rtl2832_config cfg,
981		1067
982	/* create muxed i2c adapter for demod tuner bus */	1068	/* create muxed i2c adapter for demod tuner bus */
983	priv->i2c_adapter_tuner = i2c_add_mux_adapter(i2c, &i2c->dev, priv,	1069	priv->i2c_adapter_tuner = i2c_add_mux_adapter(i2c, &i2c->dev, priv,
984	0, 1, 0, rtl2832_select, NULL);	1070	0, 1, 0, rtl2832_select, rtl2832_deselect);
985	if (priv->i2c_adapter_tuner == NULL)	1071	if (priv->i2c_adapter_tuner == NULL)
986	goto err;	1072	goto err;
987		1073