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authorYannick Fertre <yannick.fertre@st.com>2019-03-29 08:39:42 -0400
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-04-22 10:29:31 -0400
commit1a726df6078c2fa1ce07f1e086576977d99f7fcf (patch)
tree196fcd2e330e359d598aaa2e8df51aeac394a722 /drivers/media/platform/stm32/stm32-cec.c
parentb063474e2130b6bab48ac20acd9b821dfc16c171 (diff)
media: platform: stm32: wait end of transmission
It is mandatory to write CEC_CFGR only when CECEN=0. To protect transmission, a check have been added to delayed logical address modification. This patch is necessary tp pass all tests of compliance. Signed-off-by: Yannick Fertré <yannick.fertre@st.com> Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media/platform/stm32/stm32-cec.c')
-rw-r--r--drivers/media/platform/stm32/stm32-cec.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/media/platform/stm32/stm32-cec.c b/drivers/media/platform/stm32/stm32-cec.c
index 7c496bc1cf38..8a86b2cc22fa 100644
--- a/drivers/media/platform/stm32/stm32-cec.c
+++ b/drivers/media/platform/stm32/stm32-cec.c
@@ -56,6 +56,13 @@
#define ALL_TX_IT (TXEND | TXBR | TXACKE | TXERR | TXUDR | ARBLST)
#define ALL_RX_IT (RXEND | RXBR | RXACKE | RXOVR)
+/*
+ * 400 ms is the time it takes for one 16 byte message to be
+ * transferred and 5 is the maximum number of retries. Add
+ * another 100 ms as a margin.
+ */
+#define CEC_XFER_TIMEOUT_MS (5 * 400 + 100)
+
struct stm32_cec {
struct cec_adapter *adap;
struct device *dev;
@@ -188,7 +195,11 @@ static int stm32_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
{
struct stm32_cec *cec = adap->priv;
u32 oar = (1 << logical_addr) << 16;
+ u32 val;
+ /* Poll every 100µs the register CEC_CR to wait end of transmission */
+ regmap_read_poll_timeout(cec->regmap, CEC_CR, val, !(val & TXSOM),
+ 100, CEC_XFER_TIMEOUT_MS * 1000);
regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
if (logical_addr == CEC_LOG_ADDR_INVALID)