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authorSrinivas Kandagatla <srinivas.kandagatla@linaro.org>2020-03-11 14:35:44 +0300
committerVinod Koul <vkoul@kernel.org>2020-03-20 16:54:59 +0300
commita9107de4b03604ce0d279315c91b31b8065ee4ea (patch)
tree4c6fb188e1cb391bcf45ea6d24f509de2cde9823 /drivers
parentbb6d3fb354c5ee8d6bde2d576eb7220ea09862b9 (diff)
downloadlinux-a9107de4b03604ce0d279315c91b31b8065ee4ea.tar.xz
soundwire: stream: Add read_only_wordlength flag to port properties
According to SoundWire Specification Version 1.2. "A Data Port number X (in the range 0-14) which supports only one value of WordLength may implement the WordLength field in the DPX_BlockCtrl1 Register as Read-Only, returning the fixed value of WordLength in response to reads." As WSA881x interfaces in PDM mode making the only field "WordLength" in DPX_BlockCtrl1" fixed and read-only. Behaviour of writing to this register on WSA881x soundwire slave with Qualcomm Soundwire Controller is throwing up an error. Not sure how other controllers deal with writing to readonly registers, but this patch provides a way to avoid writes to DPN_BlockCtrl1 register by providing a read_only_wordlength flag in struct sdw_dpn_prop Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200311113545.23773-2-srinivas.kandagatla@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/soundwire/stream.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 178ae92b8cc1..7fb89a94d9c0 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -167,13 +167,15 @@ static int sdw_program_slave_port_params(struct sdw_bus *bus,
return ret;
}
- /* Program DPN_BlockCtrl1 register */
- ret = sdw_write(s_rt->slave, addr2, (p_params->bps - 1));
- if (ret < 0) {
- dev_err(&s_rt->slave->dev,
- "DPN_BlockCtrl1 register write failed for port %d\n",
- t_params->port_num);
- return ret;
+ if (!dpn_prop->read_only_wordlength) {
+ /* Program DPN_BlockCtrl1 register */
+ ret = sdw_write(s_rt->slave, addr2, (p_params->bps - 1));
+ if (ret < 0) {
+ dev_err(&s_rt->slave->dev,
+ "DPN_BlockCtrl1 register write failed for port %d\n",
+ t_params->port_num);
+ return ret;
+ }
}
/* Program DPN_SampleCtrl1 register */