linux-kernel - [PATCH 14/15] ASoC: cs42l42: Wait for PLL to lock before switching to it

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 2 Mar 2021 17:04:53 +0000
From:   Lucas Tanure <tanureal@...nsource.cirrus.com>
To:     James Schulman <james.schulman@...rus.com>,
        David Rhodes <david.rhodes@...rus.com>,
        Mark Brown <broonie@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>
CC:     Richard Fitzgerald <rf@...nsource.cirrus.com>,
        <alsa-devel@...a-project.org>, <patches@...nsource.cirrus.com>,
        Lucas Tanure <tanureal@...nsource.cirrus.com>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH 14/15] ASoC: cs42l42: Wait for PLL to lock before switching to it

From: Richard Fitzgerald <rf@...nsource.cirrus.com>

The PLL should have locked before using it to supply MCLK.

Signed-off-by: Richard Fitzgerald <rf@...nsource.cirrus.com>
---
 sound/soc/codecs/cs42l42.c | 12 +++++++++++-
 sound/soc/codecs/cs42l42.h |  2 ++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 68b5a450623d3..96f4e98ceaa0b 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -830,6 +830,7 @@ static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
 	unsigned int regval;
 	u8 fullScaleVol;
+	int ret;
 
 	if (mute) {
 		/* Mute the headphone */
@@ -855,9 +856,18 @@ static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
 	} else {
 		if (!cs42l42->stream_use) {
 			/* SCLK must be running before codec unmute */
-			if ((cs42l42->bclk < 11289600) && (cs42l42->sclk < 11289600))
+			if ((cs42l42->bclk < 11289600) && (cs42l42->sclk < 11289600)) {
 				snd_soc_component_update_bits(component, CS42L42_PLL_CTL1,
 							      CS42L42_PLL_START_MASK, 1);
+				ret = regmap_read_poll_timeout(cs42l42->regmap,
+							       CS42L42_PLL_LOCK_STATUS,
+							       regval,
+							       (regval & 1),
+							       CS42L42_PLL_LOCK_POLL_US,
+							       CS42L42_PLL_LOCK_TIMEOUT_US);
+				if (ret < 0)
+					dev_warn(component->dev, "PLL failed to lock: %d\n", ret);
+			}
 
 			/* Mark SCLK as present, turn off internal oscillator */
 			regmap_multi_reg_write(cs42l42->regmap, cs42l42_to_sclk_seq,
diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index a0c87f2326e69..7a5048dfade20 100644
--- a/sound/soc/codecs/cs42l42.h
+++ b/sound/soc/codecs/cs42l42.h
@@ -756,6 +756,8 @@
 #define CS42L42_NUM_SUPPLIES	5
 #define CS42L42_BOOT_TIME_US	3000
 #define CS42L42_CLOCK_SWITCH_DELAY_US 150
+#define CS42L42_PLL_LOCK_POLL_US	250
+#define CS42L42_PLL_LOCK_TIMEOUT_US	1250
 
 static const char *const cs42l42_supply_names[CS42L42_NUM_SUPPLIES] = {
 	"VA",
-- 
2.30.1