Commit 19db62ea authored by Misael Lopez Cruz's avatar Misael Lopez Cruz Committed by Mark Brown

ASoC: davinci-mcasp: Logic low for inactive output slots

The default state when serializers are in inactive slots is Hi-Z.
In some cases, there are no additional components driving the data
lines to a safe state so they might have noise.

While in inactive slots, the McASP AXR pins configured as outputs
can be driven low through the serializer pin drive mode setting
(DISMOD) to prevent such noise.
Signed-off-by: default avatarMisael Lopez Cruz <misael.lopez@ti.com>
Signed-off-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 518f6bab
...@@ -686,6 +686,8 @@ static int mcasp_common_hw_param(struct davinci_mcasp *mcasp, int stream, ...@@ -686,6 +686,8 @@ static int mcasp_common_hw_param(struct davinci_mcasp *mcasp, int stream,
if (mcasp->serial_dir[i] == TX_MODE && if (mcasp->serial_dir[i] == TX_MODE &&
tx_ser < max_active_serializers) { tx_ser < max_active_serializers) {
mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AXR(i)); mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AXR(i));
mcasp_mod_bits(mcasp, DAVINCI_MCASP_XRSRCTL_REG(i),
DISMOD_LOW, DISMOD_MASK);
tx_ser++; tx_ser++;
} else if (mcasp->serial_dir[i] == RX_MODE && } else if (mcasp->serial_dir[i] == RX_MODE &&
rx_ser < max_active_serializers) { rx_ser < max_active_serializers) {
......
...@@ -215,7 +215,10 @@ ...@@ -215,7 +215,10 @@
* DAVINCI_MCASP_XRSRCTL_BASE_REG - Serializer Control Register Bits * DAVINCI_MCASP_XRSRCTL_BASE_REG - Serializer Control Register Bits
*/ */
#define MODE(val) (val) #define MODE(val) (val)
#define DISMOD (val)(val<<2) #define DISMOD_3STATE (0x0)
#define DISMOD_LOW (0x2 << 2)
#define DISMOD_HIGH (0x3 << 2)
#define DISMOD_MASK DISMOD_HIGH
#define TXSTATE BIT(4) #define TXSTATE BIT(4)
#define RXSTATE BIT(5) #define RXSTATE BIT(5)
#define SRMOD_MASK 3 #define SRMOD_MASK 3
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment