From e949f61461ab83b094cad564c89a8d2b078b4508 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Thu, 31 Aug 2017 12:56:10 -0400 Subject: [PATCH] media: s5p-cec: add NACK detection support 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 Acked-by: Sylwester Nawrocki Cc: # for v4.12 and up Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c | 3 ++- drivers/media/platform/s5p-cec/s5p_cec.c | 11 ++++++++++- drivers/media/platform/s5p-cec/s5p_cec.h | 2 ++ 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c b/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c index 1edf667d562a..146ae6f25cdb 100644 --- a/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c +++ b/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c @@ -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; diff --git a/drivers/media/platform/s5p-cec/s5p_cec.c b/drivers/media/platform/s5p-cec/s5p_cec.c index 58d200e7c838..8837e2678bde 100644 --- a/drivers/media/platform/s5p-cec/s5p_cec.c +++ b/drivers/media/platform/s5p-cec/s5p_cec.c @@ -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, diff --git a/drivers/media/platform/s5p-cec/s5p_cec.h b/drivers/media/platform/s5p-cec/s5p_cec.h index 8bcd8dc1aeb9..86ded522ef27 100644 --- a/drivers/media/platform/s5p-cec/s5p_cec.h +++ b/drivers/media/platform/s5p-cec/s5p_cec.h @@ -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 };