[PATCH v4 3/3] thermal: qcom: add support for PMIC5 Gen3 ADC thermal monitoring

[Jishnu Prakash]

Add support for ADC_TM part of PMIC5 Gen3 in an auxiliary driver
under the Gen3 ADC driver. Its functionality is similar to that of
PMIC5 Gen2 ADC_TM, which implements the threshold setting and
interrupt generating functions, used to support thermal trip points.

In Gen3 ADC, the register interface is implemented on one or more SDAM
(Shared Direct Access Memory) peripherals instead of dedicated ADC
peripherals. Each ADC SDAM has eight channels which can be configured
for either immediate reads (main ADC driver's functionality) or ADC_TM
reads. By convention, the first channel of the first ADC SDAM is reserved
for all immediate reads and remaining channels across all SDAMs are used
for ADC_TM functionality.

On the first SDAM, the interrupt line and configuration registers are
shared between the main ADC and auxiliary ADC_TM drivers. Access to the
registers is protected through a mutex shared between the drivers. The
ADC_TM driver accesses this mutex and some other functions shared from
the main driver (like adc5_gen3_get_scaled_reading() for immediate channel
reads in the .get_temp() callback) through APIs exported into a shared
namespace.

Signed-off-by: Jishnu Prakash <jishnu.prakash@xxxxxxxxxxxxxxxx>
---
 drivers/thermal/qcom/Kconfig                  |   9 +
 drivers/thermal/qcom/Makefile                 |   1 +
 drivers/thermal/qcom/qcom-spmi-adc-tm5-gen3.c | 434 ++++++++++++++++++++++++++
 3 files changed, 444 insertions(+)

diff --git a/drivers/thermal/qcom/Kconfig b/drivers/thermal/qcom/Kconfig
index a6bb01082ec6..1acb11e4ac80 100644
--- a/drivers/thermal/qcom/Kconfig
+++ b/drivers/thermal/qcom/Kconfig
@@ -21,6 +21,15 @@ config QCOM_SPMI_ADC_TM5
 	  Thermal client sets threshold temperature for both warm and cool and
 	  gets updated when a threshold is reached.
 
+config QCOM_SPMI_ADC_TM5_GEN3
+	tristate "Qualcomm SPMI PMIC Thermal Monitor ADC5 Gen3"
+	depends on QCOM_SPMI_ADC5_GEN3
+	help
+	  This enables the auxiliary thermal driver for the ADC5 Gen3 thermal
+	  monitoring device. It shows up as a thermal zone with multiple trip points.
+	  Thermal client sets threshold temperature for both warm and cool and
+	  gets updated when a threshold is reached.
+
 config QCOM_SPMI_TEMP_ALARM
 	tristate "Qualcomm SPMI PMIC Temperature Alarm"
 	depends on OF && SPMI && IIO
diff --git a/drivers/thermal/qcom/Makefile b/drivers/thermal/qcom/Makefile
index 0fa2512042e7..828d9e7bc797 100644
--- a/drivers/thermal/qcom/Makefile
+++ b/drivers/thermal/qcom/Makefile
@@ -4,5 +4,6 @@ obj-$(CONFIG_QCOM_TSENS)	+= qcom_tsens.o
 qcom_tsens-y			+= tsens.o tsens-v2.o tsens-v1.o tsens-v0_1.o \
 				   tsens-8960.o
 obj-$(CONFIG_QCOM_SPMI_ADC_TM5)	+= qcom-spmi-adc-tm5.o
+obj-$(CONFIG_QCOM_SPMI_ADC_TM5_GEN3)	+= qcom-spmi-adc-tm5-gen3.o
 obj-$(CONFIG_QCOM_SPMI_TEMP_ALARM)	+= qcom-spmi-temp-alarm.o
 obj-$(CONFIG_QCOM_LMH)		+= lmh.o
diff --git a/drivers/thermal/qcom/qcom-spmi-adc-tm5-gen3.c b/drivers/thermal/qcom/qcom-spmi-adc-tm5-gen3.c
new file mode 100644
index 000000000000..9cf552d36868
--- /dev/null
+++ b/drivers/thermal/qcom/qcom-spmi-adc-tm5-gen3.c
@@ -0,0 +1,434 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/container_of.h>
+#include <linux/device/devres.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/iio/adc/qcom-adc5-gen3-common.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/thermal.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+#include "../thermal_hwmon.h"
+
+#define ADC_TM5_GEN3_CONFIG_REGS 12
+
+struct device;
+struct adc_tm5_gen3_chip;
+
+/**
+ * struct adc_tm5_gen3_channel_props - ADC_TM channel structure
+ * @common_props: structure with common ADC channel properties.
+ * @chip: ADC TM device.
+ * @tzd: pointer to thermal device corresponding to TM channel.
+ * @sdam_index: SDAM on which this TM channel lies.
+ * @timer: time period of recurring TM measurement.
+ * @tm_chan_index: TM channel number used.
+ * @high_thr_en: TM high threshold crossing detection enabled.
+ * @low_thr_en: TM low threshold crossing detection enabled.
+ */
+struct adc_tm5_gen3_channel_props {
+	struct adc5_channel_common_prop common_props;
+	struct adc_tm5_gen3_chip *chip;
+	struct thermal_zone_device *tzd;
+	unsigned int sdam_index;
+	unsigned int timer;
+	unsigned int tm_chan_index;
+	bool high_thr_en;
+	bool low_thr_en;
+};
+
+/**
+ * struct adc_tm5_gen3_chip - ADC Thermal Monitoring device structure
+ * @dev_data: Top-level ADC device data.
+ * @chan_props: Array of ADC_TM channel structures.
+ * @dev: SPMI ADC5 Gen3 device.
+ * @nchannels: number of TM channels allocated
+ */
+struct adc_tm5_gen3_chip {
+	struct adc5_device_data *dev_data;
+	struct adc_tm5_gen3_channel_props *chan_props;
+	struct device *dev;
+	unsigned int nchannels;
+};
+
+DEFINE_GUARD(adc5_gen3, struct adc_tm5_gen3_chip *,
+	     adc5_gen3_mutex_lock(_T->dev), adc5_gen3_mutex_unlock(_T->dev))
+
+static int get_sdam_from_irq(struct adc_tm5_gen3_chip *adc_tm5, int irq)
+{
+	for (int i = 0; i < adc_tm5->dev_data->num_sdams; i++) {
+		if (adc_tm5->dev_data->base[i].irq == irq)
+			return i;
+	}
+	return -ENOENT;
+}
+
+static irqreturn_t adctm5_gen3_isr(int irq, void *dev_id)
+{
+	struct adc_tm5_gen3_chip *adc_tm5 = dev_id;
+	int ret, sdam_num;
+	u8 tm_status[2];
+	u8 status, val;
+
+	sdam_num = get_sdam_from_irq(adc_tm5, irq);
+	if (sdam_num < 0)
+		return IRQ_NONE;
+
+	ret = adc5_gen3_read(adc_tm5->dev_data, sdam_num, ADC5_GEN3_STATUS1,
+			     &status, sizeof(status));
+	if (ret)
+		return IRQ_NONE;
+
+	if (status & ADC5_GEN3_STATUS1_CONV_FAULT) {
+		val = ADC5_GEN3_CONV_ERR_CLR_REQ;
+		adc5_gen3_status_clear(adc_tm5->dev_data, sdam_num,
+				       ADC5_GEN3_CONV_ERR_CLR, &val, 1);
+		return IRQ_HANDLED;
+	}
+
+	ret = adc5_gen3_read(adc_tm5->dev_data, sdam_num, ADC5_GEN3_TM_HIGH_STS,
+			     tm_status, sizeof(tm_status));
+	if (ret)
+		return IRQ_NONE;
+
+	if (tm_status[0] || tm_status[1])
+		return IRQ_WAKE_THREAD;
+
+	return IRQ_NONE;
+}
+
+static irqreturn_t adctm5_gen3_isr_thread(int irq, void *dev_id)
+{
+	struct adc_tm5_gen3_chip *adc_tm5 = dev_id;
+	u8 tm_status[2];
+	int sdam_index;
+
+	sdam_index = get_sdam_from_irq(adc_tm5, irq);
+	if (sdam_index < 0)
+		return IRQ_NONE;
+
+	scoped_guard(adc5_gen3, adc_tm5) {
+		int ret;
+
+		ret = adc5_gen3_read(adc_tm5->dev_data, sdam_index, ADC5_GEN3_TM_HIGH_STS,
+				     tm_status, sizeof(tm_status));
+		if (ret)
+			return IRQ_NONE;
+
+		ret = adc5_gen3_status_clear(adc_tm5->dev_data, sdam_index,
+					     ADC5_GEN3_TM_HIGH_STS_CLR, tm_status,
+					     sizeof(tm_status));
+		if (ret)
+			return IRQ_NONE;
+	}
+
+	for (int i = 0; i < adc_tm5->nchannels; i++) {
+		struct adc_tm5_gen3_channel_props *chan_prop = &adc_tm5->chan_props[i];
+		int offset = chan_prop->tm_chan_index;
+		bool upper_set, lower_set;
+
+		if (chan_prop->sdam_index != sdam_index)
+			continue;
+
+		upper_set = ((tm_status[0] & BIT(offset)) && chan_prop->high_thr_en);
+		lower_set = ((tm_status[1] & BIT(offset)) && chan_prop->low_thr_en);
+
+		if (!(upper_set || lower_set))
+			continue;
+
+		thermal_zone_device_update(chan_prop->tzd, THERMAL_TRIP_VIOLATED);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int adc_tm5_gen3_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct adc_tm5_gen3_channel_props *prop = thermal_zone_device_priv(tz);
+	struct adc_tm5_gen3_chip *adc_tm5;
+
+	if (!prop || !prop->chip)
+		return -EINVAL;
+
+	adc_tm5 = prop->chip;
+
+	return adc5_gen3_get_scaled_reading(adc_tm5->dev, &prop->common_props, temp);
+}
+
+static int adc_tm5_gen3_disable_channel(struct adc_tm5_gen3_channel_props *prop)
+{
+	struct adc_tm5_gen3_chip *adc_tm5 = prop->chip;
+	int ret;
+	u8 val;
+
+	prop->high_thr_en = false;
+	prop->low_thr_en = false;
+
+	ret = adc5_gen3_poll_wait_hs(adc_tm5->dev_data, prop->sdam_index);
+	if (ret)
+		return ret;
+
+	val = BIT(prop->tm_chan_index);
+	ret = adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index,
+			      ADC5_GEN3_TM_HIGH_STS_CLR, &val, sizeof(val));
+	if (ret)
+		return ret;
+
+	ret = adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index,
+			      ADC5_GEN3_TM_LOW_STS_CLR, &val, sizeof(val));
+	if (ret)
+		return ret;
+
+	val = MEAS_INT_DISABLE;
+	ret = adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index,
+			      ADC5_GEN3_TIMER_SEL, &val, sizeof(val));
+	if (ret)
+		return ret;
+
+	/* To indicate there is an actual conversion request */
+	val = ADC5_GEN3_CHAN_CONV_REQ | prop->tm_chan_index;
+	ret = adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index,
+			      ADC5_GEN3_PERPH_CH, &val, sizeof(val));
+	if (ret)
+		return ret;
+
+	val = ADC5_GEN3_CONV_REQ_REQ;
+	return adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index,
+			       ADC5_GEN3_CONV_REQ, &val, sizeof(val));
+}
+
+static int adc_tm5_gen3_configure(struct adc_tm5_gen3_channel_props *prop,
+				  int low_temp, int high_temp)
+{
+	struct adc_tm5_gen3_chip *adc_tm5 = prop->chip;
+	u8 buf[ADC_TM5_GEN3_CONFIG_REGS];
+	u8 conv_req;
+	u16 adc_code;
+	int ret;
+
+	ret = adc5_gen3_poll_wait_hs(adc_tm5->dev_data, prop->sdam_index);
+	if (ret < 0)
+		return ret;
+
+	ret = adc5_gen3_read(adc_tm5->dev_data, prop->sdam_index,
+			     ADC5_GEN3_SID, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	/* Write SID */
+	buf[0] = FIELD_PREP(ADC5_GEN3_SID_MASK, prop->common_props.sid);
+
+	/* Select TM channel and indicate there is an actual conversion request */
+	buf[1] = ADC5_GEN3_CHAN_CONV_REQ | prop->tm_chan_index;
+
+	buf[2] = prop->timer;
+
+	/* Digital param selection */
+	adc5_gen3_update_dig_param(&prop->common_props, &buf[3]);
+
+	/* Update fast average sample value */
+	buf[4] = FIELD_PREP(ADC5_GEN3_FAST_AVG_CTL_SAMPLES_MASK,
+			    prop->common_props.avg_samples) | ADC5_GEN3_FAST_AVG_CTL_EN;
+
+	/* Select ADC channel */
+	buf[5] = prop->common_props.channel;
+
+	/* Select HW settle delay for channel */
+	buf[6] = FIELD_PREP(ADC5_GEN3_HW_SETTLE_DELAY_MASK,
+			    prop->common_props.hw_settle_time_us);
+
+	buf[7] = 0;
+
+	/* High temperature corresponds to low voltage threshold */
+	prop->low_thr_en = (high_temp != INT_MAX);
+	if (prop->low_thr_en) {
+		adc_code = qcom_adc_tm5_gen2_temp_res_scale(high_temp);
+		put_unaligned_le16(adc_code, &buf[8]);
+		buf[7] |= ADC5_GEN3_LOW_THR_INT_EN;
+	}
+
+	/* Low temperature corresponds to high voltage threshold */
+	prop->high_thr_en = (low_temp != -INT_MAX);
+	if (prop->high_thr_en) {
+		adc_code = qcom_adc_tm5_gen2_temp_res_scale(low_temp);
+		put_unaligned_le16(adc_code, &buf[10]);
+		buf[7] |= ADC5_GEN3_HIGH_THR_INT_EN;
+	}
+
+	ret = adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index, ADC5_GEN3_SID,
+			      buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	conv_req = ADC5_GEN3_CONV_REQ_REQ;
+	return adc5_gen3_write(adc_tm5->dev_data, prop->sdam_index,
+			       ADC5_GEN3_CONV_REQ, &conv_req, sizeof(conv_req));
+}
+
+static int adc_tm5_gen3_set_trip_temp(struct thermal_zone_device *tz,
+				      int low_temp, int high_temp)
+{
+	struct adc_tm5_gen3_channel_props *prop = thermal_zone_device_priv(tz);
+	struct adc_tm5_gen3_chip *adc_tm5;
+
+	if (!prop || !prop->chip)
+		return -EINVAL;
+
+	adc_tm5 = prop->chip;
+
+	dev_dbg(adc_tm5->dev, "channel:%s, low_temp(mdegC):%d, high_temp(mdegC):%d\n",
+		prop->common_props.label, low_temp, high_temp);
+
+	guard(adc5_gen3)(adc_tm5);
+
+	return adc_tm5_gen3_configure(prop, low_temp, high_temp);
+}
+
+static const struct thermal_zone_device_ops adc_tm_ops = {
+	.get_temp = adc_tm5_gen3_get_temp,
+	.set_trips = adc_tm5_gen3_set_trip_temp,
+};
+
+static int adc_tm5_register_tzd(struct adc_tm5_gen3_chip *adc_tm5)
+{
+	struct thermal_zone_device *tzd;
+	unsigned int channel;
+	int ret;
+
+	for (int i = 0; i < adc_tm5->nchannels; i++) {
+		channel = ADC5_GEN3_V_CHAN(adc_tm5->chan_props[i].common_props);
+		tzd = devm_thermal_of_zone_register(adc_tm5->dev, channel,
+						    &adc_tm5->chan_props[i],
+						    &adc_tm_ops);
+		if (IS_ERR(tzd)) {
+			if (PTR_ERR(tzd) == -ENODEV) {
+				dev_dbg(adc_tm5->dev,
+					"thermal sensor on channel %d is not used\n",
+					channel);
+				continue;
+			}
+			return PTR_ERR(tzd);
+		}
+		adc_tm5->chan_props[i].tzd = tzd;
+		ret = devm_thermal_add_hwmon_sysfs(adc_tm5->dev, tzd);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void adc5_gen3_disable(void *data)
+{
+	struct adc_tm5_gen3_chip *adc_tm5 = data;
+
+	guard(adc5_gen3)(adc_tm5);
+
+	/* Disable all available TM channels */
+	for (int i = 0; i < adc_tm5->nchannels; i++)
+		adc_tm5_gen3_disable_channel(&adc_tm5->chan_props[i]);
+}
+
+static int adc_tm5_probe(struct auxiliary_device *aux_dev,
+			 const struct auxiliary_device_id *id)
+{
+	struct adc_tm5_gen3_chip *adc_tm5;
+	struct tm5_aux_dev_wrapper *aux_dev_wrapper;
+	struct device *dev = &aux_dev->dev;
+	int ret;
+
+	adc_tm5 = devm_kzalloc(dev, sizeof(*adc_tm5), GFP_KERNEL);
+	if (!adc_tm5)
+		return -ENOMEM;
+
+	aux_dev_wrapper = container_of(aux_dev, struct tm5_aux_dev_wrapper, aux_dev);
+
+	adc_tm5->dev = dev;
+	adc_tm5->dev_data = aux_dev_wrapper->dev_data;
+	adc_tm5->nchannels = aux_dev_wrapper->n_tm_channels;
+	adc_tm5->chan_props = devm_kcalloc(dev, aux_dev_wrapper->n_tm_channels,
+					   sizeof(*adc_tm5->chan_props), GFP_KERNEL);
+	if (!adc_tm5->chan_props)
+		return -ENOMEM;
+
+	for (int i = 0; i < adc_tm5->nchannels; i++) {
+		/*
+		 * Since the first channel of the first SDAM is reserved for
+		 * immediate ADC conversions, TM channel count must start from
+		 * the channel just after it. The variable tm_count is used to
+		 * calculate SDAM and TM channel index on that SDAM correctly
+		 * for each TM channel.
+		 */
+		int tm_count = i + 1;
+
+		adc_tm5->chan_props[i].common_props = aux_dev_wrapper->tm_props[i];
+		adc_tm5->chan_props[i].timer = MEAS_INT_1S;
+		adc_tm5->chan_props[i].sdam_index = tm_count / 8;
+		adc_tm5->chan_props[i].tm_chan_index = tm_count % 8;
+		adc_tm5->chan_props[i].chip = adc_tm5;
+	}
+
+	/*
+	 * ADC_TM channels are enabled in the loop in adc_tm5_register_tzd() as
+	 * part of the set_trips calls during thermal zone registration. This
+	 * action is to disable them all in case of probe failure.
+	 */
+	ret = devm_add_action(dev, adc5_gen3_disable, adc_tm5);
+	if (ret)
+		return ret;
+
+	ret = adc_tm5_register_tzd(adc_tm5);
+	if (ret)
+		return ret;
+
+	for (int i = 0; i < adc_tm5->dev_data->num_sdams; i++) {
+		u32 irq_flags = IRQF_ONESHOT;
+
+		/*
+		 * First SDAM's interrupt is shared between main ADC driver and
+		 * auxiliary TM driver, so its flags must include IRQF_SHARED.
+		 * This is not needed for other SDAMs as they will be used only
+		 * for TM functionality.
+		 */
+		if (i == 0)
+			irq_flags |= IRQF_SHARED;
+
+		ret = devm_request_threaded_irq(dev,
+						adc_tm5->dev_data->base[i].irq,
+						adctm5_gen3_isr,
+						adctm5_gen3_isr_thread,
+						irq_flags,
+						adc_tm5->dev_data->base[i].irq_name,
+						adc_tm5);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct auxiliary_device_id adctm5_auxiliary_id_table[] = {
+	{ .name = "qcom_spmi_adc5_gen3.adc5_tm_gen3" },
+	{ }
+};
+MODULE_DEVICE_TABLE(auxiliary, adctm5_auxiliary_id_table);
+
+static struct auxiliary_driver adctm5gen3_auxiliary_driver = {
+	.id_table = adctm5_auxiliary_id_table,
+	.probe = adc_tm5_probe,
+};
+module_auxiliary_driver(adctm5gen3_auxiliary_driver);
+
+MODULE_DESCRIPTION("SPMI PMIC Thermal Monitor ADC driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("QCOM_SPMI_ADC5_GEN3");

-- 
2.43.0