TDA998x CEC support

Move the mutex, waitqueue, timer and detect work initialisation early in the driver's initialisation, rather than being after we've registered the CEC device.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +5 -1

index 127815253a84..7f4dbca7f7f4 100644
@@ -1476,7 +1476,11 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	u32 video;
 	int rev_lo, rev_hi, ret;
 
-	mutex_init(&priv->audio_mutex); /* Protect access from audio thread */
+	mutex_init(&priv->mutex);	/* protect the page access */
+	mutex_init(&priv->audio_mutex); /* protect access from audio thread */
+	init_waitqueue_head(&priv->edid_delay_waitq);
+	timer_setup(&priv->edid_delay_timer, tda998x_edid_delay_done, 0);
+	INIT_WORK(&priv->detect_work, tda998x_detect_work);
 
 	priv->vip_cntrl_0 = VIP_CNTRL_0_SWAP_A(2) | VIP_CNTRL_0_SWAP_B(3);
 	priv->vip_cntrl_1 = VIP_CNTRL_1_SWAP_C(0) | VIP_CNTRL_1_SWAP_D(1);

@@ -1490,11 +1494,6 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	if (!priv->cec)

We no longer use the CEC client to access the CEC part itself, so we can move this later in the initialisation sequence.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +0 -3

index 7f4dbca7f7f4..4aeac2127974 100644
@@ -1490,9 +1490,6 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	priv->cec_addr = 0x34 + (client->addr & 0x03);
 	priv->current_page = 0xff;
 	priv->hdmi = client;
-	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
-	if (!priv->cec)
-		return -ENODEV;
 
 	/* wake up the device: */
 	cec_write(priv, REG_CEC_ENAMODS,

Quoted 25 lines · Russell King

We no longer use the CEC client to access the CEC part itself, so we can move this later in the initialisation sequence.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +0 -3

index 7f4dbca7f7f4..4aeac2127974 100644
@@ -1490,9 +1490,6 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	priv->cec_addr = 0x34 + (client->addr & 0x03);
 	priv->current_page = 0xff;
 	priv->hdmi = client;
-	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
-	if (!priv->cec)
-		return -ENODEV;
 
 	/* wake up the device: */
 	cec_write(priv, REG_CEC_ENAMODS,

@@ -1546,6 +1543,10 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 			CEC_FRO_IM_CLK_CTRL_GHOST_DIS | CEC_FRO_IM_CLK_CTRL_IMCLK_SEL);
 

drivers/gpu/drm/i2c/tda998x_drv.c static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv) · line 1549

Quoted 5 lines

drivers/gpu/drm/i2c/tda998x_drv.c +4 -0

 	/* initialize the optional IRQ */
+	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
+	if (!priv->cec)
+		return -ENODEV;
+

I'd move this up to before the 'initialize the optional IRQ' comment, since that should stay with the 'if (client->irq) {' line below.

Quoted 26 lines · Hans Verkuil

Quoted 25 lines · Russell King

We no longer use the CEC client to access the CEC part itself, so we can move this later in the initialisation sequence.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +0 -3

index 7f4dbca7f7f4..4aeac2127974 100644
@@ -1490,9 +1490,6 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	priv->cec_addr = 0x34 + (client->addr & 0x03);
 	priv->current_page = 0xff;
 	priv->hdmi = client;
-	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
-	if (!priv->cec)
-		return -ENODEV;
 
 	/* wake up the device: */
 	cec_write(priv, REG_CEC_ENAMODS,

@@ -1546,6 +1543,10 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 			CEC_FRO_IM_CLK_CTRL_GHOST_DIS | CEC_FRO_IM_CLK_CTRL_IMCLK_SEL);
 

Quoted 8 lines

drivers/gpu/drm/i2c/tda998x_drv.c static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv) · line 1549

Quoted 5 lines

drivers/gpu/drm/i2c/tda998x_drv.c +4 -0

 	/* initialize the optional IRQ */
+	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
+	if (!priv->cec)
+		return -ENODEV;
+

I'd move this up to before the 'initialize the optional IRQ' comment, since that should stay with the 'if (client->irq) {' line below.

I've swapped the order of patches 2 and 3, and moved this further down near where we add the real cec device in a later patch. This is starting to get quite different from the patch series that I've tested, and as I've already mentioned, testing is not going to happen for a while.

Hi Russell,

Quoted 36 lines · Russell King - ARM Linux

Quoted 26 lines · Hans Verkuil

Quoted 25 lines · Russell King

We no longer use the CEC client to access the CEC part itself, so we can move this later in the initialisation sequence.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +0 -3

index 7f4dbca7f7f4..4aeac2127974 100644
@@ -1490,9 +1490,6 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	priv->cec_addr = 0x34 + (client->addr & 0x03);
 	priv->current_page = 0xff;
 	priv->hdmi = client;
-	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
-	if (!priv->cec)
-		return -ENODEV;
 
 	/* wake up the device: */
 	cec_write(priv, REG_CEC_ENAMODS,

@@ -1546,6 +1543,10 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 			CEC_FRO_IM_CLK_CTRL_GHOST_DIS | CEC_FRO_IM_CLK_CTRL_IMCLK_SEL);
 

Quoted 8 lines

drivers/gpu/drm/i2c/tda998x_drv.c static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv) · line 1549

Quoted 5 lines

drivers/gpu/drm/i2c/tda998x_drv.c +4 -0

 	/* initialize the optional IRQ */
+	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
+	if (!priv->cec)
+		return -ENODEV;
+

I'd move this up to before the 'initialize the optional IRQ' comment, since that should stay with the 'if (client->irq) {' line below.

Quoted 6 lines

I've swapped the order of patches 2 and 3, and moved this further down near where we add the real cec device in a later patch. This is starting to get quite different from the patch series that I've tested, and as I've already mentioned, testing is not going to happen for a while.

I added support for this to am335x-boneblack-common.dtsi (see patch below), but it doesn't work. I suspect the calibration since I see these messages:

gpio-57 (nxp,calib): gpiod_direction_output: tried to set a GPIO tied to an IRQ as output

Which makes sense. I had a similar case in my cec-gpio driver and I had to completely free the interrupt before I could set the direction to output.

I do get nice interrupts when a transmit is done, so the interrupt works correctly. And it correctly detects Ack/Nack.

I looked a bit closer and I see that even without calibration the timings are reasonably
OK: 2.3 ms for a bit period instead of the recommended 2.4 ms. Slightly off but within margins.

But receiving messages fails: I get no interrupt at all. Not sure if the lack of calibration is the cause of that, or if it is something else. I can take another look once the calibration is fixed.

If tda998x_get_audio_ports() fails, and we requested the interrupt, we fail to free the interrupt before returning failure. Rework the failure cleanup code and exit paths so that we always clean up properly after an error, and always propagate the error code.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 31 ++++++++++++++++++-------------
 1 file changed, 18 insertions(+), 13 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +11 -13

index 4aeac2127974..661cb8915f2f 100644
@@ -1499,10 +1499,15 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 
 	/* read version: */
 	rev_lo = reg_read(priv, REG_VERSION_LSB);
+	if (rev_lo < 0) {
+		dev_err(&client->dev, "failed to read version: %d\n", rev_lo);
+		return rev_lo;
+	}
+
 	rev_hi = reg_read(priv, REG_VERSION_MSB);
-	if (rev_lo < 0 || rev_hi < 0) {
-		ret = rev_lo < 0 ? rev_lo : rev_hi;
-		goto fail;
+	if (rev_hi < 0) {
+		dev_err(&client->dev, "failed to read version: %d\n", rev_hi);
+		return rev_hi;
 	}
 
 	priv->rev = rev_lo | rev_hi << 8;

@@ -1526,7 +1531,7 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	default:
 		dev_err(&client->dev, "found unsupported device: %04x\n",
 			priv->rev);
-		goto fail;
+		return -ENXIO;
 	}
 
 	/* after reset, enable DDC: */

@@ -1568,7 +1573,7 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 			dev_err(&client->dev,
 				"failed to request IRQ#%u: %d\n",
 				client->irq, ret);
-			goto fail;
+			goto err_irq;
 		}
 
 		/* enable HPD irq */

@@ -1591,19 +1596,19 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 
 	ret = tda998x_get_audio_ports(priv, np);
 	if (ret)
-		goto fail;
+		goto err_audio;
 
 	if (priv->audio_port[0].format != AFMT_UNUSED)
 		tda998x_audio_codec_init(priv, &client->dev);
 
 	return 0;
-fail:
-	/* if encoder_init fails, the encoder slave is never registered,
-	 * so cleanup here:
-	 */
-	if (priv->cec)
-		i2c_unregister_device(priv->cec);
-	return -ENXIO;

Always disable and clear interrupts at probe time to ensure that the TDA998x is in a sane state. This ensures that the interrupt line, which is also the CEC clock calibration signal, is always deasserted.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/tda998x_drv.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

drivers/gpu/drm/i2c/tda998x_drv.c +9 -0

index 661cb8915f2f..e294f5b50236 100644
@@ -1547,6 +1547,15 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	cec_write(priv, REG_CEC_FRO_IM_CLK_CTRL,
 			CEC_FRO_IM_CLK_CTRL_GHOST_DIS | CEC_FRO_IM_CLK_CTRL_IMCLK_SEL);
 
+	/* ensure interrupts are disabled */
+	cec_write(priv, REG_CEC_RXSHPDINTENA, 0);
+
+	/* clear pending interrupts */
+	cec_read(priv, REG_CEC_RXSHPDINT);
+	reg_read(priv, REG_INT_FLAGS_0);
+	reg_read(priv, REG_INT_FLAGS_1);
+	reg_read(priv, REG_INT_FLAGS_2);
+
 	/* initialize the optional IRQ */
 	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
 	if (!priv->cec)

@@ -1558,11 +1567,6 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 		/* init read EDID waitqueue and HDP work */

Add the optional calibration gpio for integrated TDA9950 CEC support. This GPIO corresponds with the interrupt from the TDA998x, as the calibration requires driving the interrupt pin low.

Signed-off-by Russell King <[email protected]>

---
 Documentation/devicetree/bindings/display/bridge/tda998x.txt | 3 +++
 1 file changed, 3 insertions(+)

Add a CEC driver for the TDA9950, which is a stand-alone I2C CEC device, but is also integrated into HDMI transceivers such as the TDA9989 and TDA19989.

The TDA9950 contains a command processor which handles retransmissions and the low level bus protocol. The driver just has to read and write the messages, and handle error conditions.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/Kconfig           |   5 +
 drivers/gpu/drm/i2c/Makefile          |   1 +
 drivers/gpu/drm/i2c/tda9950.c         | 507 ++++++++++++++++++++++++++++++++++
 include/linux/platform_data/tda9950.h |  16 ++
 4 files changed, 529 insertions(+)
 create mode 100644 drivers/gpu/drm/i2c/tda9950.c
 create mode 100644 include/linux/platform_data/tda9950.h

drivers/gpu/drm/i2c/Kconfig +5 -0

index a6c92beb410a..3a232f5ff0a1 100644
@@ -26,4 +26,9 @@ config DRM_I2C_NXP_TDA998X
 	help
 	  Support for NXP Semiconductors TDA998X HDMI encoders.
 
+config DRM_I2C_NXP_TDA9950
+	tristate "NXP Semiconductors TDA9950/TDA998X HDMI CEC"
+	select CEC_NOTIFIER
+	select CEC_CORE
+
 endmenu

drivers/gpu/drm/i2c/Makefile +1 -0

index b20100c18ffb..a962f6f08568 100644
@@ -7,3 +7,4 @@ obj-$(CONFIG_DRM_I2C_SIL164) += sil164.o
 
 tda998x-y := tda998x_drv.o
 obj-$(CONFIG_DRM_I2C_NXP_TDA998X) += tda998x.o
+obj-$(CONFIG_DRM_I2C_NXP_TDA9950) += tda9950.o

drivers/gpu/drm/i2c/tda9950.c new file +150 -0

new file mode 100644
index 000000000000..6f7a37ddda05
@@ -0,0 +1,507 @@
+/*
+ *  TDA9950 Consumer Electronics Control driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * The NXP TDA9950 implements the HDMI Consumer Electronics Control
+ * interface.  The host interface is similar to a mailbox: the data
+ * registers starting at REG_CDR0 are written to send a command to the
+ * internal CPU, and replies are read from these registers.
+ *
+ * As the data registers represent a mailbox, they must be accessed
+ * as a single I2C transaction.  See the TDA9950 data sheet for details.
+ */
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_data/tda9950.h>
+#include <linux/slab.h>
+#include <drm/drm_edid.h>
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+
+enum {
+	REG_CSR = 0x00,
+	CSR_BUSY = BIT(7),
+	CSR_INT  = BIT(6),
+	CSR_ERR  = BIT(5),
+
+	REG_CER = 0x01,
+
+	REG_CVR = 0x02,
+
+	REG_CCR = 0x03,
+	CCR_RESET = BIT(7),
+	CCR_ON    = BIT(6),
+
+	REG_ACKH = 0x04,
+	REG_ACKL = 0x05,
+
+	REG_CCONR = 0x06,
+	CCONR_ENABLE_ERROR = BIT(4),
+	CCONR_RETRY_MASK = 7,
+
+	REG_CDR0 = 0x07,
+
+	CDR1_REQ = 0x00,
+	CDR1_CNF = 0x01,
+	CDR1_IND = 0x81,
+	CDR1_ERR = 0x82,
+	CDR1_IER = 0x83,
+
+	CDR2_CNF_SUCCESS    = 0x00,
+	CDR2_CNF_OFF_STATE  = 0x80,
+	CDR2_CNF_BAD_REQ    = 0x81,
+	CDR2_CNF_CEC_ACCESS = 0x82,
+	CDR2_CNF_ARB_ERROR  = 0x83,
+	CDR2_CNF_BAD_TIMING = 0x84,
+	CDR2_CNF_NACK_ADDR  = 0x85,
+	CDR2_CNF_NACK_DATA  = 0x86,
+};
+
+struct tda9950_priv {
+	struct i2c_client *client;
+	struct device *hdmi;
+	struct cec_adapter *adap;
+	struct tda9950_glue *glue;
+	u16 addresses;
+	struct cec_msg rx_msg;
+	struct cec_notifier *notify;
+	bool open;
+};
+
+static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
+{
+	struct i2c_msg msg;
+	u8 buf[cnt + 1];
+	int ret;
+
+	buf[0] = addr;
+	memcpy(buf + 1, p, cnt);
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = cnt + 1;
+	msg.buf = buf;
+
+	dev_dbg(&client->dev, "wr 0x%02x: %*ph\n", addr, cnt, p);
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0)
+		dev_err(&client->dev, "Error %d writing to cec:0x%x\n", ret, addr);
+	return ret < 0 ? ret : 0;
+}
+
+static void tda9950_write(struct i2c_client *client, u8 addr, u8 val)
+{
+	tda9950_write_range(client, addr, &val, 1);
+}
+
+static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
+{
+	struct i2c_msg msg[2];
+	int ret;
+
+	msg[0].addr = client->addr;
+	msg[0].flags = 0;
+	msg[0].len = 1;
+	msg[0].buf = &addr;
+	msg[1].addr = client->addr;
+	msg[1].flags = I2C_M_RD;
+	msg[1].len = cnt;
+	msg[1].buf = p;
+
+	ret = i2c_transfer(client->adapter, msg, 2);
+	if (ret < 0)
+		dev_err(&client->dev, "Error %d reading from cec:0x%x\n", ret, addr);
+
+	dev_dbg(&client->dev, "rd 0x%02x: %*ph\n", addr, cnt, p);
+
+	return ret;
+}
+
+static u8 tda9950_read(struct i2c_client *client, u8 addr)
+{
+	int ret;
+	u8 val;
+
+	ret = tda9950_read_range(client, addr, &val, 1);
+	if (ret < 0)
+		val = 0;
+
+	return val;
+}
+
+static irqreturn_t tda9950_irq(int irq, void *data)
+{
+	struct tda9950_priv *priv = data;
+	unsigned int tx_status;
+	u8 csr, cconr, buf[19];
+	u8 arb_lost_cnt, nack_cnt, err_cnt;
+
+	if (!priv->open)
+		return IRQ_NONE;
+
+	csr = tda9950_read(priv->client, REG_CSR);
+	if (!(csr & CSR_INT))
+		return IRQ_NONE;

drivers/gpu/drm/i2c/tda9950.c new file +27 -0

+		dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
+		return IRQ_NONE;
+	}
+
+	switch (buf[1]) {
+	case CDR1_CNF: /* transmit result */
+		arb_lost_cnt = nack_cnt = err_cnt = 0;
+		switch (buf[2]) {
+		case CDR2_CNF_SUCCESS:
+			tx_status = CEC_TX_STATUS_OK;
+			break;
+
+		case CDR2_CNF_ARB_ERROR:
+			tx_status = CEC_TX_STATUS_ARB_LOST;
+			arb_lost_cnt = cconr;
+			break;
+
+		case CDR2_CNF_NACK_ADDR:
+			tx_status = CEC_TX_STATUS_NACK;
+			nack_cnt = cconr;
+			break;
+
+		default: /* some other error, refer to TDA9950 docs */
+			dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
+				buf[2]);
+			tx_status = CEC_TX_STATUS_ERROR;
+			err_cnt = cconr;

drivers/gpu/drm/i2c/tda9950.c new file +8 -0

+		memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
+		cec_received_msg(priv->adap, &priv->rx_msg);
+		break;
+
+	default: /* unknown */
+		dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
+			buf[1]);
+		break;

drivers/gpu/drm/i2c/tda9950.c new file +195 -0

+
+	buf[0] = 2 + msg->len;
+	buf[1] = CDR1_REQ;
+	memcpy(buf + 2, msg->msg, msg->len);
+
+	if (attempts > 5)
+		attempts = 5;
+
+	tda9950_write(priv->client, REG_CCONR, attempts);
+
+	return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
+}
+
+static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
+{
+	struct tda9950_priv *priv = adap->priv;
+	u16 addresses;
+	u8 buf[2];
+
+	if (addr == CEC_LOG_ADDR_INVALID)
+		addresses = priv->addresses = 0;
+	else
+		addresses = priv->addresses |= BIT(addr);
+
+	/* TDA9950 doesn't want address 15 set */
+	addresses &= 0x7fff;
+	buf[0] = addresses >> 8;
+	buf[1] = addresses;
+
+	return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
+}
+
+/*
+ * When operating as part of the TDA998x, we need additional handling
+ * to initialise and shut down the TDA9950 part of the device.  These
+ * two hooks are provided to allow the TDA998x code to perform those
+ * activities.
+ */
+static int tda9950_glue_open(struct tda9950_priv *priv)
+{
+	int ret = 0;
+
+	if (priv->glue && priv->glue->open)
+		ret = priv->glue->open(priv->glue->data);
+
+	priv->open = true;
+
+	return ret;
+}
+
+static void tda9950_glue_release(struct tda9950_priv *priv)
+{
+	priv->open = false;
+
+	if (priv->glue && priv->glue->release)
+		priv->glue->release(priv->glue->data);
+}
+
+static int tda9950_open(struct tda9950_priv *priv)
+{
+	struct i2c_client *client = priv->client;
+	int ret;
+
+	ret = tda9950_glue_open(priv);
+	if (ret)
+		return ret;
+
+	/* Reset the TDA9950, and wait 250ms for it to recover */
+	tda9950_write(client, REG_CCR, CCR_RESET);
+	msleep(250);
+
+	tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);
+
+	/* Start the command processor */
+	tda9950_write(client, REG_CCR, CCR_ON);
+
+	return 0;
+}
+
+static void tda9950_release(struct tda9950_priv *priv)
+{
+	struct i2c_client *client = priv->client;
+	int timeout = 50;
+	u8 csr;
+
+	/* Stop the command processor */
+	tda9950_write(client, REG_CCR, 0);
+
+	/* Wait up to .5s for it to signal non-busy */
+	do {
+		csr = tda9950_read(client, REG_CSR);
+		if (!(csr & CSR_BUSY) || --timeout)
+			break;
+		msleep(10);
+	} while (1);
+
+	/* Warn the user that their IRQ may die if it's shared. */
+	if (csr & CSR_BUSY)
+		dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
+			 client->irq, csr);
+
+	tda9950_glue_release(priv);
+}
+
+static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct tda9950_priv *priv = adap->priv;
+
+	if (!enable) {
+		tda9950_release(priv);
+		return 0;
+	} else {
+		return tda9950_open(priv);
+	}
+}
+
+static const struct cec_adap_ops tda9950_cec_ops = {
+	.adap_enable = tda9950_cec_adap_enable,
+	.adap_log_addr = tda9950_cec_adap_log_addr,
+	.adap_transmit = tda9950_cec_transmit,
+};
+
+/*
+ * When operating as part of the TDA998x, we need to claim additional
+ * resources.  These two hooks permit the management of those resources.
+ */
+static void tda9950_devm_glue_exit(void *data)
+{
+	struct tda9950_glue *glue = data;
+
+	if (glue && glue->exit)
+		glue->exit(glue->data);
+}
+
+static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
+{
+	int ret;
+
+	if (glue && glue->init) {
+		ret = glue->init(glue->data);
+		if (ret)
+			return ret;
+	}
+
+	ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
+	if (ret)
+		tda9950_devm_glue_exit(glue);
+
+	return ret;
+}
+
+static void tda9950_cec_del(void *data)
+{
+	struct tda9950_priv *priv = data;
+
+	cec_delete_adapter(priv->adap);
+}
+
+static int tda9950_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct tda9950_glue *glue = client->dev.platform_data;
+	struct device *dev = &client->dev;
+	struct tda9950_priv *priv;
+	unsigned long irqflags;
+	int ret;
+	u8 cvr;
+
+	/*
+	 * We must have I2C functionality: our multi-byte accesses
+	 * must be performed as a single contiguous transaction.
+	 */
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev,
+			"adapter does not support I2C functionality\n");
+		return -ENXIO;
+	}
+
+	/* We must have an interrupt to be functional. */
+	if (client->irq <= 0) {
+		dev_err(&client->dev, "driver requires an interrupt\n");
+		return -ENXIO;
+	}
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->client = client;
+	priv->glue = glue;
+
+	i2c_set_clientdata(client, priv);
+
+	/*
+	 * If we're part of a TDA998x, we want the class devices to be

drivers/gpu/drm/i2c/tda9950.c new file +87 -0

+					  CEC_MAX_LOG_ADDRS);
+	if (IS_ERR(priv->adap))
+		return PTR_ERR(priv->adap);
+
+	ret = devm_add_action(dev, tda9950_cec_del, priv);
+	if (ret) {
+		cec_delete_adapter(priv->adap);
+		return ret;
+	}
+
+	ret = tda9950_devm_glue_init(dev, glue);
+	if (ret)
+		return ret;
+
+	ret = tda9950_glue_open(priv);
+	if (ret)
+		return ret;
+
+	cvr = tda9950_read(client, REG_CVR);
+
+	dev_info(&client->dev,
+		 "TDA9950 CEC interface, hardware version %u.%u\n",
+		 cvr >> 4, cvr & 15);
+
+	tda9950_glue_release(priv);
+
+	irqflags = IRQF_TRIGGER_FALLING;
+	if (glue)
+		irqflags = glue->irq_flags;
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
+					irqflags | IRQF_SHARED | IRQF_ONESHOT,
+					dev_name(&client->dev), priv);
+	if (ret < 0)
+		return ret;
+
+	priv->notify = cec_notifier_get(priv->hdmi);
+	if (!priv->notify)
+		return -ENOMEM;
+
+	ret = cec_register_adapter(priv->adap, priv->hdmi);
+	if (ret < 0) {
+		cec_notifier_put(priv->notify);
+		return ret;
+	}
+
+	/*
+	 * CEC documentation says we must not call cec_delete_adapter
+	 * after a successful call to cec_register_adapter().
+	 */
+	devm_remove_action(dev, tda9950_cec_del, priv);
+
+	cec_register_cec_notifier(priv->adap, priv->notify);
+
+	return 0;
+}
+
+static int tda9950_remove(struct i2c_client *client)
+{
+	struct tda9950_priv *priv = i2c_get_clientdata(client);
+
+	cec_unregister_adapter(priv->adap);
+	cec_notifier_put(priv->notify);
+
+	return 0;
+}
+
+static struct i2c_device_id tda9950_ids[] = {
+	{ "tda9950", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, tda9950_ids);
+
+static struct i2c_driver tda9950_driver = {
+	.probe = tda9950_probe,
+	.remove = tda9950_remove,
+	.driver = {
+		.name = "tda9950",
+	},
+	.id_table = tda9950_ids,
+};
+
+module_i2c_driver(tda9950_driver);
+
+MODULE_AUTHOR("Russell King <[email protected]>");
+MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver");
+MODULE_LICENSE("GPL v2");

include/linux/platform_data/tda9950.h new file +6 -0

new file mode 100644
index 000000000000..c65efd461102
@@ -0,0 +1,16 @@
+#ifndef LINUX_PLATFORM_DATA_TDA9950_H
+#define LINUX_PLATFORM_DATA_TDA9950_H
+
+struct device;
+
+struct tda9950_glue {

Hi Russell,

Some small comments below:

drivers/gpu/drm/i2c/tda9950.c line 160

Quoted 5 lines · Russell King

drivers/gpu/drm/i2c/tda9950.c new file +5 -0

+	/*
+	 * This should never happen: the data sheet says that there will
+	 * always be a valid message if the interrupt line is asserted.
+	 */
+	if (buf[0] == 0) {

Checking for <= 2 is safer. See also my comment below.

Quoted 31 lines

drivers/gpu/drm/i2c/tda9950.c new file +31 -0

+		dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
+		return IRQ_NONE;
+	}
+
+	switch (buf[1]) {
+	case CDR1_CNF: /* transmit result */
+		arb_lost_cnt = nack_cnt = err_cnt = 0;
+		switch (buf[2]) {
+		case CDR2_CNF_SUCCESS:
+			tx_status = CEC_TX_STATUS_OK;
+			break;
+
+		case CDR2_CNF_ARB_ERROR:
+			tx_status = CEC_TX_STATUS_ARB_LOST;
+			arb_lost_cnt = cconr;
+			break;
+
+		case CDR2_CNF_NACK_ADDR:
+			tx_status = CEC_TX_STATUS_NACK;
+			nack_cnt = cconr;
+			break;
+
+		default: /* some other error, refer to TDA9950 docs */
+			dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
+				buf[2]);
+			tx_status = CEC_TX_STATUS_ERROR;
+			err_cnt = cconr;
+			break;
+		}
+		/* TDA9950 executes all retries for us */
+		tx_status |= CEC_TX_STATUS_MAX_RETRIES;

drivers/gpu/drm/i2c/tda9950.c line 197

Quoted 6 lines

drivers/gpu/drm/i2c/tda9950.c new file +6 -0

+		cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
+				  nack_cnt, 0, err_cnt);
+		break;
+
+	case CDR1_IND:
+		priv->rx_msg.len = buf[0] - 2;

Does the datasheet give any guarantees that buf[0] is always between 3 and 18?

Note: it is possible for devices to send more than 16 bytes in a CEC message. Not allowed, mind you, but it can be done and I suspect some do in certain situations. So if the hardware just keeps counting you can get a rx_msg.len > 16 and then the memcpy below would overwrite memory. You want to clamp the length to max 16.

The TDA998x is a HDMI transmitter with a TDA9950 CEC engine integrated onto the same die. Add support for the TDA9950 CEC engine to the TDA998x driver.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/Kconfig       |   1 +
 drivers/gpu/drm/i2c/tda998x_drv.c | 209 +++++++++++++++++++++++++++++++++++---
 2 files changed, 196 insertions(+), 14 deletions(-)

drivers/gpu/drm/i2c/Kconfig +0 -0

index 3a232f5ff0a1..096d2139e733 100644

drivers/gpu/drm/i2c/Kconfig +0 -0

 	select SND_SOC_HDMI_CODEC if SND_SOC
 	help
 	  Support for NXP Semiconductors TDA998X HDMI encoders.

drivers/gpu/drm/i2c/tda998x_drv.c +188 -14

index e294f5b50236..3ad39d018ab6 100644
@@ -16,8 +16,10 @@
  */
 
 #include <linux/component.h>
+#include <linux/gpio/consumer.h>
 #include <linux/hdmi.h>
 #include <linux/module.h>
+#include <linux/platform_data/tda9950.h>
 #include <linux/irq.h>
 #include <sound/asoundef.h>
 #include <sound/hdmi-codec.h>

@@ -29,6 +31,8 @@
 #include <drm/drm_of.h>
 #include <drm/i2c/tda998x.h>
 
+#include <media/cec-notifier.h>
+
 #define DBG(fmt, ...) DRM_DEBUG(fmt"\n", ##__VA_ARGS__)
 
 struct tda998x_audio_port {

@@ -55,6 +59,7 @@ struct tda998x_priv {
 	struct platform_device *audio_pdev;
 	struct mutex audio_mutex;
 
+	struct mutex edid_mutex;
 	wait_queue_head_t wq_edid;
 	volatile int wq_edid_wait;
 

@@ -67,6 +72,9 @@ struct tda998x_priv {
 	struct drm_connector connector;
 
 	struct tda998x_audio_port audio_port[2];
+	struct tda9950_glue cec_glue;
+	struct gpio_desc *calib;
+	struct cec_notifier *cec_notify;
 };
 
 #define conn_to_tda998x_priv(x) \

@@ -345,6 +353,12 @@ struct tda998x_priv {
 #define REG_CEC_INTSTATUS	  0xee		      /* read */
 # define CEC_INTSTATUS_CEC	  (1 << 0)
 # define CEC_INTSTATUS_HDMI	  (1 << 1)
+#define REG_CEC_CAL_XOSC_CTRL1    0xf2
+# define CEC_CAL_XOSC_CTRL1_ENA_CAL	BIT(0)
+#define REG_CEC_DES_FREQ2         0xf5
+# define CEC_DES_FREQ2_DIS_AUTOCAL BIT(7)
+#define REG_CEC_CLK               0xf6
+# define CEC_CLK_FRO              0x11
 #define REG_CEC_FRO_IM_CLK_CTRL   0xfb                /* read/write */
 # define CEC_FRO_IM_CLK_CTRL_GHOST_DIS (1 << 7)
 # define CEC_FRO_IM_CLK_CTRL_ENA_OTP   (1 << 6)

@@ -359,6 +373,7 @@ struct tda998x_priv {
 # define CEC_RXSHPDLEV_HPD        (1 << 1)
 
 #define REG_CEC_ENAMODS           0xff                /* read/write */
+# define CEC_ENAMODS_EN_CEC_CLK   (1 << 7)
 # define CEC_ENAMODS_DIS_FRO      (1 << 6)
 # define CEC_ENAMODS_DIS_CCLK     (1 << 5)
 # define CEC_ENAMODS_EN_RXSENS    (1 << 2)

@@ -417,6 +432,114 @@ cec_read(struct tda998x_priv *priv, u8 addr)
 	return val;
 }
 
+static void cec_enamods(struct tda998x_priv *priv, u8 mods, bool enable)
+{
+	int val = cec_read(priv, REG_CEC_ENAMODS);
+
+	if (val < 0)
+		return;
+
+	if (enable)
+		val |= mods;
+	else
+		val &= ~mods;
+
+	cec_write(priv, REG_CEC_ENAMODS, val);
+}
+
+static void tda998x_cec_set_calibration(struct tda998x_priv *priv, bool enable)
+{
+	if (enable) {
+		u8 val;
+
+		cec_write(priv, 0xf3, 0xc0);
+		cec_write(priv, 0xf4, 0xd4);
+
+		/* Enable automatic calibration mode */
+		val = cec_read(priv, REG_CEC_DES_FREQ2);
+		val &= ~CEC_DES_FREQ2_DIS_AUTOCAL;
+		cec_write(priv, REG_CEC_DES_FREQ2, val);
+
+		/* Enable free running oscillator */
+		cec_write(priv, REG_CEC_CLK, CEC_CLK_FRO);
+		cec_enamods(priv, CEC_ENAMODS_DIS_FRO, false);
+
+		cec_write(priv, REG_CEC_CAL_XOSC_CTRL1,
+			  CEC_CAL_XOSC_CTRL1_ENA_CAL);
+	} else {
+		cec_write(priv, REG_CEC_CAL_XOSC_CTRL1, 0);
+	}
+}
+
+/*
+ * Calibration for the internal oscillator: we need to set calibration mode,
+ * and then pulse the IRQ line low for a 10ms ± 1% period.
+ */
+static void tda998x_cec_calibration(struct tda998x_priv *priv)
+{
+	struct gpio_desc *calib = priv->calib;
+
+	mutex_lock(&priv->edid_mutex);
+	if (priv->hdmi->irq > 0)
+		disable_irq(priv->hdmi->irq);
+	gpiod_direction_output(calib, 1);
+	tda998x_cec_set_calibration(priv, true);
+
+	local_irq_disable();
+	gpiod_set_value(calib, 0);
+	mdelay(10);
+	gpiod_set_value(calib, 1);
+	local_irq_enable();
+
+	tda998x_cec_set_calibration(priv, false);
+	gpiod_direction_input(calib);
+	if (priv->hdmi->irq > 0)
+		enable_irq(priv->hdmi->irq);
+	mutex_unlock(&priv->edid_mutex);
+}
+
+static int tda998x_cec_hook_init(void *data)
+{
+	struct tda998x_priv *priv = data;
+	struct gpio_desc *calib;
+
+	calib = gpiod_get(&priv->hdmi->dev, "nxp,calib", GPIOD_ASIS);
+	if (IS_ERR(calib)) {
+		dev_warn(&priv->hdmi->dev, "failed to get calibration gpio: %ld\n",
+			 PTR_ERR(calib));
+		return PTR_ERR(calib);
+	}
+
+	priv->calib = calib;
+
+	return 0;
+}
+
+static void tda998x_cec_hook_exit(void *data)
+{
+	struct tda998x_priv *priv = data;
+
+	gpiod_put(priv->calib);
+	priv->calib = NULL;
+}
+
+static int tda998x_cec_hook_open(void *data)
+{
+	struct tda998x_priv *priv = data;
+
+	cec_enamods(priv, CEC_ENAMODS_EN_CEC_CLK | CEC_ENAMODS_EN_CEC, true);
+	tda998x_cec_calibration(priv);
+
+	return 0;
+}
+
+static void tda998x_cec_hook_release(void *data)
+{
+	struct tda998x_priv *priv = data;
+
+	cec_enamods(priv, CEC_ENAMODS_EN_CEC_CLK | CEC_ENAMODS_EN_CEC, false);
+}
+
 static int
 set_page(struct tda998x_priv *priv, u16 reg)
 {

@@ -657,10 +780,13 @@ static irqreturn_t tda998x_irq_thread(int irq, void *data)
 			sta, cec, lvl, flag0, flag1, flag2);
 
 		if (cec & CEC_RXSHPDINT_HPD) {
-			if (lvl & CEC_RXSHPDLEV_HPD)
+			if (lvl & CEC_RXSHPDLEV_HPD) {
 				tda998x_edid_delay_start(priv);
-			else
+			} else {
 				schedule_work(&priv->detect_work);
+				cec_notifier_set_phys_addr(priv->cec_notify,
+						   CEC_PHYS_ADDR_INVALID);
+			}
 
 			handled = true;
 		}

@@ -981,6 +1107,8 @@ static int tda998x_connector_fill_modes(struct drm_connector *connector,
 	if (connector->edid_blob_ptr) {
 		struct edid *edid = (void *)connector->edid_blob_ptr->data;
 
+		cec_notifier_set_phys_addr_from_edid(priv->cec_notify, edid);
+
 		priv->sink_has_audio = drm_detect_monitor_audio(edid);
 	} else {
 		priv->sink_has_audio = false;

@@ -1024,6 +1152,8 @@ static int read_edid_block(void *data, u8 *buf, unsigned int blk, size_t length)
 	offset = (blk & 1) ? 128 : 0;
 	segptr = blk / 2;
 
+	mutex_lock(&priv->edid_mutex);
+
 	reg_write(priv, REG_DDC_ADDR, 0xa0);
 	reg_write(priv, REG_DDC_OFFS, offset);
 	reg_write(priv, REG_DDC_SEGM_ADDR, 0x60);

@@ -1043,14 +1173,15 @@ static int read_edid_block(void *data, u8 *buf, unsigned int blk, size_t length)
 					msecs_to_jiffies(100));
 		if (i < 0) {
 			dev_err(&priv->hdmi->dev, "read edid wait err %d\n", i);
-			return i;
+			ret = i;
+			goto failed;
 		}
 	} else {
 		for (i = 100; i > 0; i--) {
 			msleep(1);
 			ret = reg_read(priv, REG_INT_FLAGS_2);
 			if (ret < 0)
-				return ret;
+				goto failed;
 			if (ret & INT_FLAGS_2_EDID_BLK_RD)
 				break;
 		}

@@ -1058,17 +1189,22 @@ static int read_edid_block(void *data, u8 *buf, unsigned int blk, size_t length)
 
 	if (i == 0) {
 		dev_err(&priv->hdmi->dev, "read edid timeout\n");
-		return -ETIMEDOUT;
+		ret = -ETIMEDOUT;
+		goto failed;
 	}
 
 	ret = reg_read_range(priv, REG_EDID_DATA_0, buf, length);
 	if (ret != length) {
 		dev_err(&priv->hdmi->dev, "failed to read edid block %d: %d\n",
 			blk, ret);
-		return ret;
+		goto failed;
 	}
 
-	return 0;
+	ret = 0;
+
+ failed:
+	mutex_unlock(&priv->edid_mutex);
+	return ret;
 }
 
 static int tda998x_connector_get_modes(struct drm_connector *connector)

@@ -1424,6 +1560,9 @@ static void tda998x_destroy(struct tda998x_priv *priv)
 	cancel_work_sync(&priv->detect_work);
 
 	i2c_unregister_device(priv->cec);
+
+	if (priv->cec_notify)
+		cec_notifier_put(priv->cec_notify);
 }
 
 /* I2C driver functions */

@@ -1473,11 +1612,13 @@ static int tda998x_get_audio_ports(struct tda998x_priv *priv,
 static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 {
 	struct device_node *np = client->dev.of_node;
+	struct i2c_board_info cec_info;
 	u32 video;
 	int rev_lo, rev_hi, ret;
 
 	mutex_init(&priv->mutex);	/* protect the page access */
 	mutex_init(&priv->audio_mutex); /* protect access from audio thread */
+	mutex_init(&priv->edid_mutex);
 	init_waitqueue_head(&priv->edid_delay_waitq);
 	timer_setup(&priv->edid_delay_timer, tda998x_edid_delay_done, 0);
 	INIT_WORK(&priv->detect_work, tda998x_detect_work);

@@ -1556,11 +1697,8 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 	reg_read(priv, REG_INT_FLAGS_1);
 	reg_read(priv, REG_INT_FLAGS_2);
 
-	/* initialize the optional IRQ */
-	priv->cec = i2c_new_dummy(client->adapter, priv->cec_addr);
-	if (!priv->cec)
-		return -ENODEV;
 
+	/* initialize the optional IRQ */
 	if (client->irq) {
 		unsigned long irq_flags;
 

@@ -1569,6 +1707,9 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 
 		irq_flags =
 			irqd_get_trigger_type(irq_get_irq_data(client->irq));
+
+		priv->cec_glue.irq_flags = irq_flags;
+
 		irq_flags |= IRQF_SHARED | IRQF_ONESHOT;
 		ret = request_threaded_irq(client->irq, NULL,
 					   tda998x_irq_thread, irq_flags,

@@ -1577,13 +1718,46 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 			dev_err(&client->dev,
 				"failed to request IRQ#%u: %d\n",
 				client->irq, ret);
-			goto err_irq;
+			return ret;
 		}
 
 		/* enable HPD irq */
 		cec_write(priv, REG_CEC_RXSHPDINTENA, CEC_RXSHPDLEV_HPD);
 	}
 
+	priv->cec_notify = cec_notifier_get(&client->dev);
+	if (!priv->cec_notify) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	priv->cec_glue.parent = &client->dev;
+	priv->cec_glue.data = priv;
+	priv->cec_glue.init = tda998x_cec_hook_init;
+	priv->cec_glue.exit = tda998x_cec_hook_exit;
+	priv->cec_glue.open = tda998x_cec_hook_open;
+	priv->cec_glue.release = tda998x_cec_hook_release;
+
+	/*
+	 * Some TDA998x are actually two I2C devices merged onto one piece
+	 * of silicon: TDA9989 and TDA19989 combine the HDMI transmitter
+	 * with a slightly modified TDA9950 CEC device.  The CEC device
+	 * is at the TDA9950 address, with the address pins strapped across
+	 * to the TDA998x address pins.  Hence, it always has the same
+	 * offset.
+	 */
+	memset(&cec_info, 0, sizeof(cec_info));
+	strlcpy(cec_info.type, "tda9950", sizeof(cec_info.type));
+	cec_info.addr = priv->cec_addr;
+	cec_info.platform_data = &priv->cec_glue;
+	cec_info.irq = client->irq;
+
+	priv->cec = i2c_new_device(client->adapter, &cec_info);
+	if (!priv->cec) {
+		free_irq(priv->hdmi->irq, priv);
+		return -ENODEV;
+	}
+
 	/* enable EDID read irq: */
 	reg_set(priv, REG_INT_FLAGS_2, INT_FLAGS_2_EDID_BLK_RD);
 

@@ -1610,8 +1784,15 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
 err_audio:
 	if (client->irq)
 		free_irq(client->irq, priv);
-err_irq:
-	i2c_unregister_device(priv->cec);
+fail:
+	/* if encoder_init fails, the encoder slave is never registered,

Hi Russell,

Thanks for this patch series!

Quoted 15 lines · Russell King

The TDA998x is a HDMI transmitter with a TDA9950 CEC engine integrated onto the same die. Add support for the TDA9950 CEC engine to the TDA998x driver.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/Kconfig       |   1 +
 drivers/gpu/drm/i2c/tda998x_drv.c | 209 +++++++++++++++++++++++++++++++++++---
 2 files changed, 196 insertions(+), 14 deletions(-)

drivers/gpu/drm/i2c/Kconfig +0 -0

index 3a232f5ff0a1..096d2139e733 100644

drivers/gpu/drm/i2c/Kconfig config DRM_I2C_SIL164 · line 25

Quoted 4 lines

drivers/gpu/drm/i2c/Kconfig +1 -0

@@ -22,6 +22,7 @@ config DRM_I2C_SIL164
 config DRM_I2C_NXP_TDA998X
 	tristate "NXP Semiconductors TDA998X HDMI encoder"
 	default m if DRM_TILCDC
+	select CEC_NOTIFIER

I believe this should be 'select CEC_CORE if CEC_NOTIFIER', conform the other drivers that do something similar.

Otherwise if tda9950 is configured as a module, and this as built-in, then cec is built as a module as well and this can't find the cec functions from the module.

Quoted 28 lines · Hans Verkuil

Hi Russell,

Thanks for this patch series!

Quoted 15 lines · Russell King

The TDA998x is a HDMI transmitter with a TDA9950 CEC engine integrated onto the same die. Add support for the TDA9950 CEC engine to the TDA998x driver.

Signed-off-by Russell King <[email protected]>

---
 drivers/gpu/drm/i2c/Kconfig       |   1 +
 drivers/gpu/drm/i2c/tda998x_drv.c | 209 +++++++++++++++++++++++++++++++++++---
 2 files changed, 196 insertions(+), 14 deletions(-)

drivers/gpu/drm/i2c/Kconfig +0 -0

index 3a232f5ff0a1..096d2139e733 100644

drivers/gpu/drm/i2c/Kconfig config DRM_I2C_SIL164 · line 25

Quoted 4 lines

drivers/gpu/drm/i2c/Kconfig +1 -0

@@ -22,6 +22,7 @@ config DRM_I2C_SIL164
 config DRM_I2C_NXP_TDA998X
 	tristate "NXP Semiconductors TDA998X HDMI encoder"
 	default m if DRM_TILCDC
+	select CEC_NOTIFIER

I believe this should be 'select CEC_CORE if CEC_NOTIFIER', conform the other drivers that do something similar.

Quoted 3 lines

Otherwise if tda9950 is configured as a module, and this as built-in, then cec is built as a module as well and this can't find the cec functions from the module.

You mean when we have:

CONFIG_DRM_I2C_NXP_TDA998X=y
CONFIG_DRM_I2C_NXP_TDA9950=m

?

That appears to work fine with:

CONFIG_CEC_CORE=m
CONFIG_CEC_NOTIFIER=y

in 4.14, as that's exactly the configuration I test with on Dove. Maybe that's changed recently, or maybe I haven't noticed it not working (I can't test it at the moment, sorry.)