[PATCH v2] ASoC: codecs: wsa884x: Implement temperature reading and hwmon

From: Krzysztof Kozlowski
Date: Sat Jul 13 2024 - 05:56:54 EST

Read temperature of the speaker and expose it via hwmon interface, which
will be later used during calibration of speaker protection algorithms.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

---

Changes in v2:
1. Add missing dependency on HWMON for y!=m builds (kernel test robot
report: undefined reference to
`devm_hwmon_device_register_with_info').
---
sound/soc/codecs/Kconfig | 1 +
sound/soc/codecs/wsa884x.c | 197 +++++++++++++++++++++++++++++++++++++
2 files changed, 198 insertions(+)

diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index 97bb69c9848d..09a0b209bc2f 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -2447,6 +2447,7 @@ config SND_SOC_WSA883X
config SND_SOC_WSA884X
tristate "WSA884X Codec"
depends on SOUNDWIRE
+ depends on HWMON || !HWMON
select REGMAP_SOUNDWIRE
help
This enables support for Qualcomm WSA8840/WSA8845/WSA8845H Class-D
diff --git a/sound/soc/codecs/wsa884x.c b/sound/soc/codecs/wsa884x.c
index 7b19df9c1728..5f4acd66f942 100644
--- a/sound/soc/codecs/wsa884x.c
+++ b/sound/soc/codecs/wsa884x.c
@@ -5,11 +5,14 @@
*/

#include <linux/bitfield.h>
+#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
+#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
@@ -301,8 +304,28 @@
#define WSA884X_PA_FSM_MSK1 (WSA884X_DIG_CTRL0_BASE + 0x3b)
#define WSA884X_PA_FSM_BYP_CTL (WSA884X_DIG_CTRL0_BASE + 0x3c)
#define WSA884X_PA_FSM_BYP0 (WSA884X_DIG_CTRL0_BASE + 0x3d)
+#define WSA884X_PA_FSM_BYP0_DC_CAL_EN_MASK 0x01
+#define WSA884X_PA_FSM_BYP0_DC_CAL_EN_SHIFT 0
+#define WSA884X_PA_FSM_BYP0_CLK_WD_EN_MASK 0x02
+#define WSA884X_PA_FSM_BYP0_CLK_WD_EN_SHIFT 1
+#define WSA884X_PA_FSM_BYP0_BG_EN_MASK 0x04
+#define WSA884X_PA_FSM_BYP0_BG_EN_SHIFT 2
+#define WSA884X_PA_FSM_BYP0_BOOST_EN_MASK 0x08
+#define WSA884X_PA_FSM_BYP0_BOOST_EN_SHIFT 3
+#define WSA884X_PA_FSM_BYP0_PA_EN_MASK 0x10
+#define WSA884X_PA_FSM_BYP0_PA_EN_SHIFT 4
+#define WSA884X_PA_FSM_BYP0_D_UNMUTE_MASK 0x20
+#define WSA884X_PA_FSM_BYP0_D_UNMUTE_SHIFT 5
+#define WSA884X_PA_FSM_BYP0_SPKR_PROT_EN_MASK 0x40
+#define WSA884X_PA_FSM_BYP0_SPKR_PROT_EN_SHIFT 6
+#define WSA884X_PA_FSM_BYP0_TSADC_EN_MASK 0x80
+#define WSA884X_PA_FSM_BYP0_TSADC_EN_SHIFT 7
#define WSA884X_PA_FSM_BYP1 (WSA884X_DIG_CTRL0_BASE + 0x3e)
#define WSA884X_TADC_VALUE_CTL (WSA884X_DIG_CTRL0_BASE + 0x50)
+#define WSA884X_TADC_VALUE_CTL_TEMP_VALUE_RD_EN_MASK 0x01
+#define WSA884X_TADC_VALUE_CTL_TEMP_VALUE_RD_EN_SHIFT 0
+#define WSA884X_TADC_VALUE_CTL_VBAT_VALUE_RD_EN_MASK 0x02
+#define WSA884X_TADC_VALUE_CTL_VBAT_VALUE_RD_EN_SHIFT 1
#define WSA884X_TEMP_DETECT_CTL (WSA884X_DIG_CTRL0_BASE + 0x51)
#define WSA884X_TEMP_DIN_MSB (WSA884X_DIG_CTRL0_BASE + 0x52)
#define WSA884X_TEMP_DIN_LSB (WSA884X_DIG_CTRL0_BASE + 0x53)
@@ -691,6 +714,17 @@
SNDRV_PCM_FMTBIT_S24_LE |\
SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S32_LE)

+/* Two-point trimming for temperature calibration */
+#define WSA884X_T1_TEMP -10L
+#define WSA884X_T2_TEMP 150L
+
+/*
+ * Device will report senseless data in many cases, so discard any measurements
+ * outside of valid range.
+ */
+#define WSA884X_LOW_TEMP_THRESHOLD 5
+#define WSA884X_HIGH_TEMP_THRESHOLD 45
+
struct wsa884x_priv {
struct regmap *regmap;
struct device *dev;
@@ -706,6 +740,13 @@ struct wsa884x_priv {
int active_ports;
int dev_mode;
bool hw_init;
+ /*
+ * Protects temperature reading code (related to speaker protection) and
+ * fields: temperature and pa_on.
+ */
+ struct mutex sp_lock;
+ unsigned int temperature;
+ bool pa_on;
};

enum {
@@ -1650,6 +1691,10 @@ static int wsa884x_spkr_event(struct snd_soc_dapm_widget *w,

switch (event) {
case SND_SOC_DAPM_POST_PMU:
+ mutex_lock(&wsa884x->sp_lock);
+ wsa884x->pa_on = true;
+ mutex_unlock(&wsa884x->sp_lock);
+
wsa884x_spkr_post_pmu(component, wsa884x);

snd_soc_component_write_field(component, WSA884X_PDM_WD_CTL,
@@ -1661,6 +1706,10 @@ static int wsa884x_spkr_event(struct snd_soc_dapm_widget *w,
snd_soc_component_write_field(component, WSA884X_PDM_WD_CTL,
WSA884X_PDM_WD_CTL_PDM_WD_EN_MASK,
0x0);
+
+ mutex_lock(&wsa884x->sp_lock);
+ wsa884x->pa_on = false;
+ mutex_unlock(&wsa884x->sp_lock);
break;
}

@@ -1800,6 +1849,144 @@ static struct snd_soc_dai_driver wsa884x_dais[] = {
},
};

+static int wsa884x_get_temp(struct wsa884x_priv *wsa884x, long *temp)
+{
+ unsigned int d1_msb = 0, d1_lsb = 0, d2_msb = 0, d2_lsb = 0;
+ unsigned int dmeas_msb = 0, dmeas_lsb = 0;
+ int d1, d2, dmeas;
+ unsigned int mask;
+ long val;
+ int ret;
+
+ guard(mutex)(&wsa884x->sp_lock);
+
+ if (wsa884x->pa_on) {
+ /*
+ * Reading temperature is possible only when Power Amplifier is
+ * off. Report last cached data.
+ */
+ *temp = wsa884x->temperature;
+ return 0;
+ }
+
+ ret = pm_runtime_resume_and_get(wsa884x->dev);
+ if (ret < 0)
+ return ret;
+
+ mask = WSA884X_PA_FSM_BYP0_DC_CAL_EN_MASK |
+ WSA884X_PA_FSM_BYP0_CLK_WD_EN_MASK |
+ WSA884X_PA_FSM_BYP0_BG_EN_MASK |
+ WSA884X_PA_FSM_BYP0_D_UNMUTE_MASK |
+ WSA884X_PA_FSM_BYP0_SPKR_PROT_EN_MASK |
+ WSA884X_PA_FSM_BYP0_TSADC_EN_MASK;
+ /*
+ * Here and further do not care about read or update failures.
+ * For example, before turning on Power Amplifier for the first
+ * time, reading WSA884X_TEMP_DIN_MSB will always return 0.
+ * Instead, check if returned value is within reasonable
+ * thresholds.
+ */
+ regmap_update_bits(wsa884x->regmap, WSA884X_PA_FSM_BYP0, mask, mask);
+
+ regmap_update_bits(wsa884x->regmap, WSA884X_TADC_VALUE_CTL,
+ WSA884X_TADC_VALUE_CTL_TEMP_VALUE_RD_EN_MASK,
+ FIELD_PREP(WSA884X_TADC_VALUE_CTL_TEMP_VALUE_RD_EN_MASK, 0x0));
+
+ regmap_read(wsa884x->regmap, WSA884X_TEMP_DIN_MSB, &dmeas_msb);
+ regmap_read(wsa884x->regmap, WSA884X_TEMP_DIN_LSB, &dmeas_lsb);
+
+ regmap_update_bits(wsa884x->regmap, WSA884X_TADC_VALUE_CTL,
+ WSA884X_TADC_VALUE_CTL_TEMP_VALUE_RD_EN_MASK,
+ FIELD_PREP(WSA884X_TADC_VALUE_CTL_TEMP_VALUE_RD_EN_MASK, 0x1));
+
+ regmap_read(wsa884x->regmap, WSA884X_OTP_REG_1, &d1_msb);
+ regmap_read(wsa884x->regmap, WSA884X_OTP_REG_2, &d1_lsb);
+ regmap_read(wsa884x->regmap, WSA884X_OTP_REG_3, &d2_msb);
+ regmap_read(wsa884x->regmap, WSA884X_OTP_REG_4, &d2_lsb);
+
+ regmap_update_bits(wsa884x->regmap, WSA884X_PA_FSM_BYP0, mask, 0x0);
+
+ dmeas = (((dmeas_msb & 0xff) << 0x8) | (dmeas_lsb & 0xff)) >> 0x6;
+ d1 = (((d1_msb & 0xff) << 0x8) | (d1_lsb & 0xff)) >> 0x6;
+ d2 = (((d2_msb & 0xff) << 0x8) | (d2_lsb & 0xff)) >> 0x6;
+
+ if (d1 == d2) {
+ /* Incorrect data in OTP? */
+ ret = -EINVAL;
+ goto out;
+ }
+
+ val = WSA884X_T1_TEMP + (((dmeas - d1) * (WSA884X_T2_TEMP - WSA884X_T1_TEMP))/(d2 - d1));
+
+ dev_dbg(wsa884x->dev, "Measured temp %ld (dmeas=%d, d1=%d, d2=%d)\n",
+ val, dmeas, d1, d2);
+
+ if ((val > WSA884X_LOW_TEMP_THRESHOLD) &&
+ (val < WSA884X_HIGH_TEMP_THRESHOLD)) {
+ wsa884x->temperature = val;
+ *temp = val;
+ ret = 0;
+ } else {
+ ret = -EAGAIN;
+ }
+
+out:
+ pm_runtime_mark_last_busy(wsa884x->dev);
+ pm_runtime_put_autosuspend(wsa884x->dev);
+
+ return ret;
+}
+
+static umode_t wsa884x_hwmon_is_visible(const void *data,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel)
+{
+ if (type != hwmon_temp)
+ return 0;
+
+ switch (attr) {
+ case hwmon_temp_input:
+ return 0444;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int wsa884x_hwmon_read(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, long *temp)
+{
+ int ret;
+
+ switch (attr) {
+ case hwmon_temp_input:
+ ret = wsa884x_get_temp(dev_get_drvdata(dev), temp);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ return ret;
+}
+
+static const struct hwmon_channel_info *const wsa884x_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_ops wsa884x_hwmon_ops = {
+ .is_visible = wsa884x_hwmon_is_visible,
+ .read = wsa884x_hwmon_read,
+};
+
+static const struct hwmon_chip_info wsa884x_hwmon_chip_info = {
+ .ops = &wsa884x_hwmon_ops,
+ .info = wsa884x_hwmon_info,
+};
+
static void wsa884x_reset_powerdown(void *data)
{
struct wsa884x_priv *wsa884x = data;
@@ -1849,6 +2036,7 @@ static int wsa884x_probe(struct sdw_slave *pdev,
{
struct device *dev = &pdev->dev;
struct wsa884x_priv *wsa884x;
+ struct device *hwmon;
unsigned int i;
int ret;

@@ -1856,6 +2044,8 @@ static int wsa884x_probe(struct sdw_slave *pdev,
if (!wsa884x)
return -ENOMEM;

+ mutex_init(&wsa884x->sp_lock);
+
for (i = 0; i < WSA884X_SUPPLIES_NUM; i++)
wsa884x->supplies[i].supply = wsa884x_supply_name[i];

@@ -1913,6 +2103,13 @@ static int wsa884x_probe(struct sdw_slave *pdev,
regcache_cache_only(wsa884x->regmap, true);
wsa884x->hw_init = true;

+ hwmon = devm_hwmon_device_register_with_info(dev, "wsa884x", wsa884x,
+ &wsa884x_hwmon_chip_info,
+ NULL);
+ if (IS_ERR(hwmon))
+ return dev_err_probe(dev, PTR_ERR(hwmon),
+ "Failed to register hwmon sensor\n");
+
pm_runtime_set_autosuspend_delay(dev, 3000);
pm_runtime_use_autosuspend(dev);
pm_runtime_mark_last_busy(dev);
--
2.43.0