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media: s5p-cec: add NACK detection support

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The s5p-cec driver returned CEC_TX_STATUS_ERROR for the NACK condition.

Some digging into the datasheet uncovered the S5P_CEC_TX_STAT1 register where
bit 0 indicates if the transmit was nacked or not.

Use this to return the correct CEC_TX_STATUS_NACK status to userspace.

This was the only driver that couldn't tell a NACK from another error, and
that was very unusual. And a potential problem for applications as well.

Tested with my Odroid-U3.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: <stable@vger.kernel.org>      # for v4.12 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Hans Verkuil 2017-08-31 12:56:10 -04:00 committed by Mauro Carvalho Chehab
parent 81b79c71e5
commit e949f61461
3 changed files with 14 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
View file

@ -172,7 +172,8 @@ u32 s5p_cec_get_status(struct s5p_cec_dev *cec)
{
u32 status = 0;
status = readb(cec->reg + S5P_CEC_STATUS_0);
status = readb(cec->reg + S5P_CEC_STATUS_0) & 0xf;
status |= (readb(cec->reg + S5P_CEC_TX_STAT1) & 0xf) << 4;
status |= readb(cec->reg + S5P_CEC_STATUS_1) << 8;
status |= readb(cec->reg + S5P_CEC_STATUS_2) << 16;
status |= readb(cec->reg + S5P_CEC_STATUS_3) << 24;

11
drivers/media/platform/s5p-cec/s5p_cec.c
View file

@ -92,7 +92,10 @@ static irqreturn_t s5p_cec_irq_handler(int irq, void *priv)
dev_dbg(cec->dev, "irq received\n");
if (status & CEC_STATUS_TX_DONE) {
if (status & CEC_STATUS_TX_ERROR) {
if (status & CEC_STATUS_TX_NACK) {
dev_dbg(cec->dev, "CEC_STATUS_TX_NACK set\n");
cec->tx = STATE_NACK;
} else if (status & CEC_STATUS_TX_ERROR) {
dev_dbg(cec->dev, "CEC_STATUS_TX_ERROR set\n");
cec->tx = STATE_ERROR;
} else {
@ -135,6 +138,12 @@ static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
cec->tx = STATE_IDLE;
break;
case STATE_NACK:
cec_transmit_done(cec->adap,
CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
0, 1, 0, 0);
cec->tx = STATE_IDLE;
break;
case STATE_ERROR:
cec_transmit_done(cec->adap,
CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,

2
drivers/media/platform/s5p-cec/s5p_cec.h
View file

@ -35,6 +35,7 @@
#define CEC_STATUS_TX_TRANSFERRING (1 << 1)
#define CEC_STATUS_TX_DONE (1 << 2)
#define CEC_STATUS_TX_ERROR (1 << 3)
#define CEC_STATUS_TX_NACK (1 << 4)
#define CEC_STATUS_TX_BYTES (0xFF << 8)
#define CEC_STATUS_RX_RUNNING (1 << 16)
#define CEC_STATUS_RX_RECEIVING (1 << 17)
@ -55,6 +56,7 @@ enum cec_state {
STATE_IDLE,
STATE_BUSY,
STATE_DONE,
STATE_NACK,
STATE_ERROR
};