[PATCH 3.13 16/46] ASoC: max98090: make REVISION_ID readable

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stephen Warren <swarren@nvidia.com>

commit e126a646f77fdd66978785cb0a3a5e46b07aee2e upstream.

The REVISION_ID register is not currently marked readable. snd_soc_read()
refuses to read the register, and hence probe() fails.

Fixes: d4807ad2c4c0 ("regmap: Check readable regs in _regmap_read")
[exposed the bug, by checking for readability]
Fixes: 685e42154dcf ("ASoC: Replace max98090 Device Driver")
[left out this register from the readable list]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 sound/soc/codecs/max98090.c |    1 +
 1 file changed, 1 insertion(+)

--- a/sound/soc/codecs/max98090.c
+++ b/sound/soc/codecs/max98090.c
@@ -336,6 +336,7 @@ static bool max98090_readable_register(s
 	case M98090_REG_RECORD_TDM_SLOT:
 	case M98090_REG_SAMPLE_RATE:
 	case M98090_REG_DMIC34_BIQUAD_BASE ... M98090_REG_DMIC34_BIQUAD_BASE + 0x0E:
+	case M98090_REG_REVISION_ID:
 		return true;
 	default:
 		return false;