new file mode 100644
@@ -0,0 +1,116 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Kernel driver bt1-pvt
+=====================
+
+Supported chips:
+
+ * Baikal-T1 PVT sensor (in SoC)
+
+ Prefix: 'bt1-pvt'
+
+ Addresses scanned: -
+
+ Datasheet: Provided by BAIKAL ELECTRONICS upon request and under NDA
+
+Authors:
+ Maxim Kaurkin <maxim.kaurkin@baikalelectronics.ru>
+ Serge Semin <Sergey.Semin@baikalelectronics.ru>
+
+Description
+-----------
+
+This driver implements support for the hardware monitoring capabilities of the
+embedded into Baikal-T1 process, voltage and temperature sensors. PVT IP-core
+consists of one temperature and four voltage sensors, which can be used to
+monitor the chip internal environment like heating, supply voltage and
+transistors performance. The driver can optionally provide the hwmon alarms
+for each sensor the PVT controller supports. The alarms functionality is made
+compile-time configurable due to the hardware interface implementation
+peculiarity, which is connected with an ability to convert data from only one
+sensor at a time. Additional limitation is that the controller performs the
+thresholds checking synchronously with the data conversion procedure. Due to
+these in order to have the hwmon alarms automatically detected the driver code
+must switch from one sensor to another, read converted data and manually check
+the threshold status bits. Depending on the measurements timeout settings
+(update_interval sysfs node value) this design may cause additional burden on
+the system performance. So in case if alarms are unnecessary in your system
+design it's recommended to have them disabled to prevent the PVT IRQs being
+periodically raised to get the data cache/alarms status up to date. By default
+in alarm-less configuration the data conversion is performed by the driver
+on demand when read operation is requested via corresponding _input-file.
+
+Temperature Monitoring
+----------------------
+
+Temperature is measured with 10-bit resolution and reported in millidegree
+Celsius. The driver performs all the scaling by itself therefore reports true
+temperatures that don't need any user-space adjustments. While the data
+translation formulae isn't linear, which gives us non-linear discreteness,
+it's close to one, but giving a bit better accuracy for higher temperatures.
+The temperature input is mapped as follows (the last column indicates the input
+ranges)::
+
+ temp1: CPU embedded diode -48.38C - +147.438C
+
+In case if the alarms kernel config is enabled in the driver the temperature input
+has associated min and max limits which trigger an alarm when crossed.
+
+Voltage Monitoring
+------------------
+
+The voltage inputs are also sampled with 10-bit resolution and reported in
+millivolts. But in this case the data translation formulae is linear, which
+provides a constant measurements discreteness. The data scaling is also
+performed by the driver, so returning true millivolts. The voltage inputs are
+mapped as follows (the last column indicates the input ranges)::
+
+ in0: VDD (processor core) 0.62V - 1.168V
+ in1: Low-Vt (low voltage threshold) 0.62V - 1.168V
+ in2: High-Vt (high voltage threshold) 0.62V - 1.168V
+ in3: Standard-Vt (standard voltage threshold) 0.62V - 1.168V
+
+In case if the alarms configis enabled in the driver the voltage inputs
+have associated min and max limits which trigger an alarm when crossed.
+
+Sysfs Attributes
+----------------
+
+Following is a list of all sysfs attributes that the driver provides, their
+permissions and a short description:
+
+=============================== ======= =======================================
+Name Perm Description
+=============================== ======= =======================================
+update_interval RW Measurements update interval per
+ sensor.
+temp1_type RO Sensor type (always 1 as CPU embedded
+ diode).
+temp1_label RO CPU Core Temperature sensor.
+temp1_input RO Measured temperature in millidegree
+ Celsius.
+temp1_min RW Low limit for temp input.
+temp1_max RW High limit for temp input.
+temp1_min_alarm RO Temperature input alarm. Returns 1 if
+ temperature input went below min limit,
+ 0 otherwise.
+temp1_max_alarm RO Temperature input alarm. Returns 1 if
+ temperature input went above max limit,
+ 0 otherwise.
+temp1_trim RW Temperature sensor trimming factor in
+ millidegree Celsius. It can be used to
+ manually adjust the temperature
+ measurements within 7.130 degrees
+ Celsius.
+in[0-3]_label RO CPU Voltage sensor (either core or
+ low/high/standard thresholds).
+in[0-3]_input RO Measured voltage in millivolts.
+in[0-3]_min RW Low limit for voltage input.
+in[0-3]_max RW High limit for voltage input.
+in[0-3]_min_alarm RO Voltage input alarm. Returns 1 if
+ voltage input went below min limit,
+ 0 otherwise.
+in[0-3]_max_alarm RO Voltage input alarm. Returns 1 if
+ voltage input went above max limit,
+ 0 otherwise.
+=============================== ======= =======================================
@@ -43,6 +43,7 @@ Hardware Monitoring Kernel Drivers
asc7621
aspeed-pwm-tacho
bel-pfe
+ bt1-pvt
coretemp
da9052
da9055
@@ -404,6 +404,31 @@ config SENSORS_ATXP1
This driver can also be built as a module. If so, the module
will be called atxp1.
+config SENSORS_BT1_PVT
+ tristate "Baikal-T1 Process, Voltage, Temperature sensor driver"
+ depends on MIPS_BAIKAL_T1 || COMPILE_TEST
+ help
+ If you say yes here you get support for Baikal-T1 PVT sensor
+ embedded into the SoC.
+
+ This driver can also be built as a module. If so, the module will be
+ called bt1-pvt.
+
+config SENSORS_BT1_PVT_ALARMS
+ bool "Enable Baikal-T1 PVT sensor alarms"
+ depends on SENSORS_BT1_PVT
+ help
+ Baikal-T1 PVT IP-block provides threshold registers for each
+ supported sensor. But the corresponding interrupts might be
+ generated by the thresholds comparator only in synchronization with
+ a data conversion. Additionally there is only one sensor data can
+ be converted at a time. All of these makes the interface impossible
+ to be used for the hwmon alarms implementation without periodic
+ switch between the PVT sensors. By default the data conversion is
+ performed on demand from the user-space. If this config is enabled
+ the data conversion will be periodically performed and the data will be
+ saved in the internal driver cache.
+
config SENSORS_DRIVETEMP
tristate "Hard disk drives with temperature sensors"
depends on SCSI && ATA
@@ -53,6 +53,7 @@ obj-$(CONFIG_SENSORS_ASC7621) += asc7621.o
obj-$(CONFIG_SENSORS_ASPEED) += aspeed-pwm-tacho.o
obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
+obj-$(CONFIG_SENSORS_BT1_PVT) += bt1-pvt.o
obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o
obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
new file mode 100644
@@ -0,0 +1,1155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
+ *
+ * Authors:
+ * Maxim Kaurkin <maxim.kaurkin@baikalelectronics.ru>
+ * Serge Semin <Sergey.Semin@baikalelectronics.ru>
+ *
+ * Baikal-T1 Process, Voltage, Temperature sensor driver
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/seqlock.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include "bt1-pvt.h"
+
+/*
+ * For the sake of the code simplification we created the sensors info table
+ * with the sensor names, activation modes, threshold registers base address
+ * and the thresholds bit fields.
+ */
+static const struct pvt_sensor_info pvt_info[] = {
+ PVT_SENSOR_INFO(0, "CPU Core Temperature", hwmon_temp, TEMP, TTHRES),
+ PVT_SENSOR_INFO(0, "CPU Core Voltage", hwmon_in, VOLT, VTHRES),
+ PVT_SENSOR_INFO(1, "CPU Core Low-Vt", hwmon_in, LVT, LTHRES),
+ PVT_SENSOR_INFO(2, "CPU Core High-Vt", hwmon_in, HVT, HTHRES),
+ PVT_SENSOR_INFO(3, "CPU Core Standard-Vt", hwmon_in, SVT, STHRES),
+};
+
+/*
+ * The original translation formulae of the temperature (in degrees of Celsius)
+ * to PVT data and vice-versa are following:
+ * N = 1.8322e-8*(T^4) + 2.343e-5*(T^3) + 8.7018e-3*(T^2) + 3.9269*(T^1) +
+ * 1.7204e2,
+ * T = -1.6743e-11*(N^4) + 8.1542e-8*(N^3) + -1.8201e-4*(N^2) +
+ * 3.1020e-1*(N^1) - 4.838e1,
+ * where T = [-48.380, 147.438]C and N = [0, 1023].
+ * They must be accordingly altered to be suitable for the integer arithmetics.
+ * The technique is called 'factor redistribution', which just makes sure the
+ * multiplications and divisions are made so to have a result of the operations
+ * within the integer numbers limit. In addition we need to translate the
+ * formulae to accept millidegrees of Celsius. Here what they look like after
+ * the alterations:
+ * N = (18322e-20*(T^4) + 2343e-13*(T^3) + 87018e-9*(T^2) + 39269e-3*T +
+ * 17204e2) / 1e4,
+ * T = -16743e-12*(D^4) + 81542e-9*(D^3) - 182010e-6*(D^2) + 310200e-3*D -
+ * 48380,
+ * where T = [-48380, 147438] mC and N = [0, 1023].
+ */
+const static struct pvt_poly poly_temp_to_N = {
+ .total_divider = 10000,
+ .terms = {
+ {4, 18322, 10000, 10000},
+ {3, 2343, 10000, 10},
+ {2, 87018, 10000, 10},
+ {1, 39269, 1000, 1},
+ {0, 1720400, 1, 1}
+ }
+};
+
+const static struct pvt_poly poly_N_to_temp = {
+ .total_divider = 1,
+ .terms = {
+ {4, -16743, 1000, 1},
+ {3, 81542, 1000, 1},
+ {2, -182010, 1000, 1},
+ {1, 310200, 1000, 1},
+ {0, -48380, 1, 1}
+ }
+};
+
+/*
+ * Similar alterations are performed for the voltage conversion equations.
+ * The original formulae are:
+ * N = 1.8658e3*V - 1.1572e3,
+ * V = (N + 1.1572e3) / 1.8658e3,
+ * where V = [0.620, 1.168] V and N = [0, 1023].
+ * After the optimization they looks as follows:
+ * N = (18658e-3*V - 11572) / 10,
+ * V = N * 10^5 / 18658 + 11572 * 10^4 / 18658.
+ */
+const static struct pvt_poly poly_volt_to_N = {
+ .total_divider = 10,
+ .terms = {
+ {1, 18658, 1000, 1},
+ {0, -11572, 1, 1}
+ }
+};
+
+const static struct pvt_poly poly_N_to_volt = {
+ .total_divider = 10,
+ .terms = {
+ {1, 100000, 18658, 1},
+ {0, 115720000, 1, 18658}
+ }
+};
+
+/*
+ * Here is the polynomial calculation function, which performs the
+ * redistributed terms calculations. It's pretty straightforward. We walk
+ * over each degree term up to the free one, and perform the redistributed
+ * multiplication of the term coefficient, its divider (as for the rationale
+ * fraction representation), data power and the rational fraction divider
+ * leftover. Then all of this is collected in a total sum variable, which
+ * value is normalized by the total divider before being returned.
+ */
+static long pvt_calc_poly(const struct pvt_poly *poly, long data)
+{
+ const struct pvt_poly_term *term = poly->terms;
+ long tmp, ret = 0;
+ int deg;
+
+ do {
+ tmp = term->coef;
+ for (deg = 0; deg < term->deg; ++deg)
+ tmp = mult_frac(tmp, data, term->divider);
+ ret += tmp / term->divider_leftover;
+ } while ((term++)->deg);
+
+ return ret / poly->total_divider;
+}
+
+static inline u32 pvt_update(void __iomem *reg, u32 mask, u32 data)
+{
+ u32 old;
+
+ old = readl_relaxed(reg);
+ writel((old & ~mask) | (data & mask), reg);
+
+ return old & mask;
+}
+
+/*
+ * Baikal-T1 PVT mode can be updated only when the controller is disabled.
+ * So first we disable it, then set the new mode together with the controller
+ * getting back enabled. The same concerns the temperature trim and
+ * measurements timeout. If it is necessary the interface mutex is supposed
+ * to be locked at the time the operations are performed.
+ */
+static inline void pvt_set_mode(struct pvt_hwmon *pvt, u32 mode)
+{
+ u32 old;
+
+ mode = FIELD_PREP(PVT_CTRL_MODE_MASK, mode);
+
+ old = pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_MODE_MASK | PVT_CTRL_EN,
+ mode | old);
+}
+
+static inline u32 pvt_calc_trim(unsigned int temp)
+{
+ temp = clamp_val(temp, 0, PVT_TRIM_TEMP);
+
+ return DIV_ROUND_UP(temp, PVT_TRIM_STEP);
+}
+
+static inline void pvt_set_trim(struct pvt_hwmon *pvt, u32 trim)
+{
+ u32 old;
+
+ trim = FIELD_PREP(PVT_CTRL_TRIM_MASK, trim);
+
+ old = pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_TRIM_MASK | PVT_CTRL_EN,
+ trim | old);
+}
+
+static inline void pvt_set_tout(struct pvt_hwmon *pvt, u32 tout)
+{
+ u32 old;
+
+ old = pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
+ writel(tout, pvt->regs + PVT_TTIMEOUT);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, old);
+}
+
+/*
+ * This driver can optionally provide the hwmon alarms for each sensor the PVT
+ * controller supports. The alarms functionality is made compile-time
+ * configurable due to the hardware interface implementation peculiarity
+ * described further in this comment. So in case if alarms are unnecessary in
+ * your system design it's recommended to have them disabled to prevent the PVT
+ * IRQs being periodically raised to get the data cache/alarms status up to
+ * date.
+ *
+ * Baikal-T1 PVT embedded controller is based on the Analog Bits PVT sensor,
+ * but is equipped with a dedicated control wrapper. It exposes the PVT
+ * sub-block registers space via the APB3 bus. In addition the wrapper provides
+ * a common interrupt vector of the sensors conversion completion events and
+ * threshold value alarms. Alas the wrapper interface hasn't been fully thought
+ * through. There is only one sensor can be activated at a time, for which the
+ * thresholds comparator is enabled right after the data conversion is
+ * completed. Due to this if alarms need to be implemented for all available
+ * sensors we can't just set the thresholds and enable the interrupts. We need
+ * to enable the sensors one after another and let the controller to detect
+ * the alarms by itself at each conversion. This also makes pointless to handle
+ * the alarms interrupts, since in occasion they happen synchronously with
+ * data conversion completion. The best driver design would be to have the
+ * completion interrupts enabled only and keep the converted value in the
+ * driver data cache. This solution is implemented if hwmon alarms are enabled
+ * in this driver. In case if the alarms are disabled, the conversion is
+ * performed on demand at the time a sensors input file is read.
+ */
+
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+
+#define pvt_hard_isr NULL
+
+static irqreturn_t pvt_soft_isr(int irq, void *data)
+{
+ const struct pvt_sensor_info *info;
+ struct pvt_hwmon *pvt = data;
+ struct pvt_cache *cache;
+ u32 val, thres_sts, old;
+
+ /*
+ * DVALID bit will be cleared by reading the data. We need to save the
+ * status before the next conversion happens. Threshold events will be
+ * handled a bit later.
+ */
+ thres_sts = readl(pvt->regs + PVT_RAW_INTR_STAT);
+
+ /*
+ * Then lets recharge the PVT interface with the next sampling mode.
+ * Lock the interface mutex to serialize trim, timeouts and alarm
+ * thresholds settings.
+ */
+ cache = &pvt->cache[pvt->sensor];
+ info = &pvt_info[pvt->sensor];
+ pvt->sensor = (pvt->sensor == PVT_SENSOR_LAST) ?
+ PVT_SENSOR_FIRST : (pvt->sensor + 1);
+
+ /*
+ * For some reason we have to mask the interrupt before changing the
+ * mode, otherwise sometimes the temperature mode doesn't get
+ * activated even though the actual mode in the ctrl register
+ * corresponds to one. Then we read the data. By doing so we also
+ * recharge the data conversion. After this the mode corresponding
+ * to the next sensor in the row is set. Finally we enable the
+ * interrupts back.
+ */
+ mutex_lock(&pvt->iface_mtx);
+
+ old = pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID,
+ PVT_INTR_DVALID);
+
+ val = readl(pvt->regs + PVT_DATA);
+
+ pvt_set_mode(pvt, pvt_info[pvt->sensor].mode);
+
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID, old);
+
+ mutex_unlock(&pvt->iface_mtx);
+
+ /*
+ * We can now update the data cache with data just retrieved from the
+ * sensor. Lock write-seqlock to make sure the reader has a coherent
+ * data.
+ */
+ write_seqlock(&cache->data_seqlock);
+
+ cache->data = FIELD_GET(PVT_DATA_DATA_MASK, val);
+
+ write_sequnlock(&cache->data_seqlock);
+
+ /*
+ * While PVT core is doing the next mode data conversion, we'll check
+ * whether the alarms were triggered for the current sensor. Note that
+ * according to the documentation only one threshold IRQ status can be
+ * set at a time, that's why if-else statement is utilized.
+ */
+ if ((thres_sts & info->thres_sts_lo) ^ cache->thres_sts_lo) {
+ WRITE_ONCE(cache->thres_sts_lo, thres_sts & info->thres_sts_lo);
+ hwmon_notify_event(pvt->hwmon, info->type, info->attr_min_alarm,
+ info->channel);
+ } else if ((thres_sts & info->thres_sts_hi) ^ cache->thres_sts_hi) {
+ WRITE_ONCE(cache->thres_sts_hi, thres_sts & info->thres_sts_hi);
+ hwmon_notify_event(pvt->hwmon, info->type, info->attr_max_alarm,
+ info->channel);
+ }
+
+ return IRQ_HANDLED;
+}
+
+inline umode_t pvt_limit_is_visible(enum pvt_sensor_type type)
+{
+ return 0644;
+}
+
+inline umode_t pvt_alarm_is_visible(enum pvt_sensor_type type)
+{
+ return 0444;
+}
+
+static int pvt_read_data(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ long *val)
+{
+ struct pvt_cache *cache = &pvt->cache[type];
+ unsigned int seq;
+ u32 data;
+
+ do {
+ seq = read_seqbegin(&cache->data_seqlock);
+ data = cache->data;
+ } while (read_seqretry(&cache->data_seqlock, seq));
+
+ if (type == PVT_TEMP)
+ *val = pvt_calc_poly(&poly_N_to_temp, data);
+ else
+ *val = pvt_calc_poly(&poly_N_to_volt, data);
+
+ return 0;
+}
+
+static int pvt_read_limit(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ bool is_low, long *val)
+{
+ u32 data;
+
+ /* No need in serialization, since it is just read from MMIO. */
+ data = readl(pvt->regs + pvt_info[type].thres_base);
+
+ if (is_low)
+ data = FIELD_GET(PVT_THRES_LO_MASK, data);
+ else
+ data = FIELD_GET(PVT_THRES_HI_MASK, data);
+
+ if (type == PVT_TEMP)
+ *val = pvt_calc_poly(&poly_N_to_temp, data);
+ else
+ *val = pvt_calc_poly(&poly_N_to_volt, data);
+
+ return 0;
+}
+
+static int pvt_write_limit(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ bool is_low, long val)
+{
+ u32 data, limit, mask;
+ int ret;
+
+ if (type == PVT_TEMP) {
+ val = clamp(val, PVT_TEMP_MIN, PVT_TEMP_MAX);
+ data = pvt_calc_poly(&poly_temp_to_N, val);
+ } else {
+ val = clamp(val, PVT_VOLT_MIN, PVT_VOLT_MAX);
+ data = pvt_calc_poly(&poly_volt_to_N, val);
+ }
+
+ /* Serialize limit update, since a part of the register is changed. */
+ ret = mutex_lock_interruptible(&pvt->iface_mtx);
+ if (ret)
+ return ret;
+
+ /* Make sure the upper and lower ranges don't intersect. */
+ limit = readl(pvt->regs + pvt_info[type].thres_base);
+ if (is_low) {
+ limit = FIELD_GET(PVT_THRES_HI_MASK, limit);
+ data = clamp_val(data, PVT_DATA_MIN, limit);
+ data = FIELD_PREP(PVT_THRES_LO_MASK, data);
+ mask = PVT_THRES_LO_MASK;
+ } else {
+ limit = FIELD_GET(PVT_THRES_LO_MASK, limit);
+ data = clamp_val(data, limit, PVT_DATA_MAX);
+ data = FIELD_PREP(PVT_THRES_HI_MASK, data);
+ mask = PVT_THRES_HI_MASK;
+ }
+
+ pvt_update(pvt->regs + pvt_info[type].thres_base, mask, data);
+
+ mutex_unlock(&pvt->iface_mtx);
+
+ return 0;
+}
+
+static int pvt_read_alarm(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ bool is_low, long *val)
+{
+ if (is_low)
+ *val = !!READ_ONCE(pvt->cache[type].thres_sts_lo);
+ else
+ *val = !!READ_ONCE(pvt->cache[type].thres_sts_hi);
+
+ return 0;
+}
+
+static const struct hwmon_channel_info *pvt_channel_info[] = {
+ HWMON_CHANNEL_INFO(chip,
+ HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_TYPE | HWMON_T_LABEL |
+ HWMON_T_MIN | HWMON_T_MIN_ALARM |
+ HWMON_T_MAX | HWMON_T_MAX_ALARM),
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_LABEL |
+ HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX | HWMON_I_MAX_ALARM,
+ HWMON_I_INPUT | HWMON_I_LABEL |
+ HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX | HWMON_I_MAX_ALARM,
+ HWMON_I_INPUT | HWMON_I_LABEL |
+ HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX | HWMON_I_MAX_ALARM,
+ HWMON_I_INPUT | HWMON_I_LABEL |
+ HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX | HWMON_I_MAX_ALARM),
+ NULL
+};
+
+#else /* !CONFIG_SENSORS_BT1_PVT_ALARMS */
+
+static irqreturn_t pvt_hard_isr(int irq, void *data)
+{
+ struct pvt_hwmon *pvt = data;
+ struct pvt_cache *cache;
+ u32 val;
+
+ /*
+ * Mask the DVALID interrupt so after exiting from the handler a
+ * repeated conversion wouldn't happen.
+ */
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID,
+ PVT_INTR_DVALID);
+
+ /*
+ * Nothing special for alarm-less driver. Just read the data, update
+ * the cache and notify a waiter of this event.
+ */
+ val = readl(pvt->regs + PVT_DATA);
+ if (!(val & PVT_DATA_VALID)) {
+ dev_err(pvt->dev, "Got IRQ when data isn't valid\n");
+ return IRQ_HANDLED;
+ }
+
+ cache = &pvt->cache[pvt->sensor];
+
+ WRITE_ONCE(cache->data, FIELD_GET(PVT_DATA_DATA_MASK, val));
+
+ complete(&cache->conversion);
+
+ return IRQ_HANDLED;
+}
+
+#define pvt_soft_isr NULL
+
+inline umode_t pvt_limit_is_visible(enum pvt_sensor_type type)
+{
+ return 0;
+}
+
+inline umode_t pvt_alarm_is_visible(enum pvt_sensor_type type)
+{
+ return 0;
+}
+
+static int pvt_read_data(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ long *val)
+{
+ struct pvt_cache *cache = &pvt->cache[type];
+ u32 data;
+ int ret;
+
+ /*
+ * Lock PVT conversion interface until data cache is updated. The
+ * data read procedure is following: set the requested PVT sensor
+ * mode, enable IRQ and conversion, wait until conversion is finished,
+ * then disable conversion and IRQ, and read the cached data.
+ */
+ ret = mutex_lock_interruptible(&pvt->iface_mtx);
+ if (ret)
+ return ret;
+
+ pvt->sensor = type;
+ pvt_set_mode(pvt, pvt_info[type].mode);
+
+ /*
+ * Unmask the DVALID interrupt and enable the sensors conversions.
+ * Do the reverse procedure when conversion is done.
+ */
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID, 0);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, PVT_CTRL_EN);
+
+ wait_for_completion(&cache->conversion);
+
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID,
+ PVT_INTR_DVALID);
+
+ data = READ_ONCE(cache->data);
+
+ mutex_unlock(&pvt->iface_mtx);
+
+ if (type == PVT_TEMP)
+ *val = pvt_calc_poly(&poly_N_to_temp, data);
+ else
+ *val = pvt_calc_poly(&poly_N_to_volt, data);
+
+ return 0;
+}
+
+static int pvt_read_limit(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ bool is_low, long *val)
+{
+ return -EOPNOTSUPP;
+}
+
+static int pvt_write_limit(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ bool is_low, long val)
+{
+ return -EOPNOTSUPP;
+}
+
+static int pvt_read_alarm(struct pvt_hwmon *pvt, enum pvt_sensor_type type,
+ bool is_low, long *val)
+{
+ return -EOPNOTSUPP;
+}
+
+static const struct hwmon_channel_info *pvt_channel_info[] = {
+ HWMON_CHANNEL_INFO(chip,
+ HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_TYPE | HWMON_T_LABEL),
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL),
+ NULL
+};
+
+#endif /* !CONFIG_SENSORS_BT1_PVT_ALARMS */
+
+static inline bool pvt_hwmon_channel_is_valid(enum hwmon_sensor_types type,
+ int ch)
+{
+ switch (type) {
+ case hwmon_temp:
+ if (ch < 0 || ch >= PVT_TEMP_CHS)
+ return false;
+ break;
+ case hwmon_in:
+ if (ch < 0 || ch >= PVT_VOLT_CHS)
+ return false;
+ break;
+ default:
+ break;
+ }
+
+ /* The rest of the types are independent from the channel number. */
+ return true;
+}
+
+static umode_t pvt_hwmon_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int ch)
+{
+ if (!pvt_hwmon_channel_is_valid(type, ch))
+ return 0;
+
+ switch (type) {
+ case hwmon_chip:
+ switch (attr) {
+ case hwmon_chip_update_interval:
+ return 0644;
+ }
+ break;
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ case hwmon_temp_type:
+ case hwmon_temp_label:
+ return 0444;
+ case hwmon_temp_min:
+ case hwmon_temp_max:
+ return pvt_limit_is_visible(ch);
+ case hwmon_temp_min_alarm:
+ case hwmon_temp_max_alarm:
+ return pvt_alarm_is_visible(ch);
+ }
+ break;
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_input:
+ case hwmon_in_label:
+ return 0444;
+ case hwmon_in_min:
+ case hwmon_in_max:
+ return pvt_limit_is_visible(PVT_VOLT + ch);
+ case hwmon_in_min_alarm:
+ case hwmon_in_max_alarm:
+ return pvt_alarm_is_visible(PVT_VOLT + ch);
+ }
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int pvt_read_timeout(struct pvt_hwmon *pvt, long *val)
+{
+ unsigned long rate;
+ ktime_t kt;
+ u32 data;
+
+ rate = clk_get_rate(pvt->clks[PVT_CLOCK_REF].clk);
+ if (!rate)
+ return -ENODEV;
+
+ /*
+ * Don't bother with mutex here, since we just read data from MMIO.
+ * We also have to scale the ticks timeout up to compensate the
+ * ms-ns-data translations.
+ */
+ data = readl(pvt->regs + PVT_TTIMEOUT) + 1;
+
+ /*
+ * Calculate ref-clock based delay (Ttotal) between two consecutive
+ * data samples of the same sensor. So we first must calculate the
+ * delay introduced by the internal ref-clock timer (Tref * Fclk).
+ * Then add the constant timeout cuased by each conversion latency
+ * (Tmin). The basic formulae for each conversion is following:
+ * Ttotal = Tref * Fclk + Tmin
+ * Note if alarms are enabled the sensors are polled one after
+ * another, so in order to have the delay being applicable for each
+ * sensor the requested value must be equally redistirbuted.
+ */
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+ kt = ktime_set(PVT_SENSORS_NUM * (u64)data, 0);
+ kt = ktime_divns(kt, rate);
+ kt = ktime_add_ns(kt, PVT_SENSORS_NUM * PVT_TOUT_MIN);
+#else
+ kt = ktime_set(data, 0);
+ kt = ktime_divns(kt, rate);
+ kt = ktime_add_ns(kt, PVT_TOUT_MIN);
+#endif
+
+ /* Return the result in msec as hwmon sysfs interface requires. */
+ *val = ktime_to_ms(kt);
+
+ return 0;
+}
+
+static int pvt_write_timeout(struct pvt_hwmon *pvt, long val)
+{
+ unsigned long rate;
+ ktime_t kt;
+ u32 data;
+ int ret;
+
+ rate = clk_get_rate(pvt->clks[PVT_CLOCK_REF].clk);
+ if (!rate)
+ return -ENODEV;
+
+ /*
+ * If alarms are enabled, the requested timeout must be divided
+ * between all available sensors to have the requested delay
+ * applicable to each individual sensor.
+ */
+ kt = ms_to_ktime(val);
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+ kt = ktime_divns(kt, PVT_SENSORS_NUM);
+#endif
+
+ /*
+ * Subtract a constant lag, which always persists due to the limited
+ * PVT sampling rate. Make sure the timeout is not negative.
+ */
+ kt = ktime_sub_ns(kt, PVT_TOUT_MIN);
+ if (ktime_to_ns(kt) < 0)
+ kt = ktime_set(0, 0);
+
+ /*
+ * Finally recalculate the timeout in terms of the reference clock
+ * period.
+ */
+ data = ktime_divns(kt * rate, NSEC_PER_SEC);
+
+ /*
+ * Update the measurements delay, but lock the interface first, since
+ * we have to disable PVT in order to have the new delay actually
+ * updated.
+ */
+ ret = mutex_lock_interruptible(&pvt->iface_mtx);
+ if (ret)
+ return ret;
+
+ pvt_set_tout(pvt, data);
+
+ mutex_unlock(&pvt->iface_mtx);
+
+ return 0;
+}
+
+static int pvt_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int ch, long *val)
+{
+ struct pvt_hwmon *pvt = dev_get_drvdata(dev);
+
+ if (!pvt_hwmon_channel_is_valid(type, ch))
+ return -EINVAL;
+
+ switch (type) {
+ case hwmon_chip:
+ switch (attr) {
+ case hwmon_chip_update_interval:
+ return pvt_read_timeout(pvt, val);
+ }
+ break;
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ return pvt_read_data(pvt, ch, val);
+ case hwmon_temp_type:
+ *val = 1;
+ return 0;
+ case hwmon_temp_min:
+ return pvt_read_limit(pvt, ch, true, val);
+ case hwmon_temp_max:
+ return pvt_read_limit(pvt, ch, false, val);
+ case hwmon_temp_min_alarm:
+ return pvt_read_alarm(pvt, ch, true, val);
+ case hwmon_temp_max_alarm:
+ return pvt_read_alarm(pvt, ch, false, val);
+ }
+ break;
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_input:
+ return pvt_read_data(pvt, PVT_VOLT + ch, val);
+ case hwmon_in_min:
+ return pvt_read_limit(pvt, PVT_VOLT + ch, true, val);
+ case hwmon_in_max:
+ return pvt_read_limit(pvt, PVT_VOLT + ch, false, val);
+ case hwmon_in_min_alarm:
+ return pvt_read_alarm(pvt, PVT_VOLT + ch, true, val);
+ case hwmon_in_max_alarm:
+ return pvt_read_alarm(pvt, PVT_VOLT + ch, false, val);
+ }
+ break;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int pvt_hwmon_read_string(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int ch, const char **str)
+{
+ if (!pvt_hwmon_channel_is_valid(type, ch))
+ return -EINVAL;
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_label:
+ *str = pvt_info[ch].label;
+ return 0;
+ }
+ break;
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_label:
+ *str = pvt_info[PVT_VOLT + ch].label;
+ return 0;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+int pvt_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int ch, long val)
+{
+ struct pvt_hwmon *pvt = dev_get_drvdata(dev);
+
+ if (!pvt_hwmon_channel_is_valid(type, ch))
+ return -EINVAL;
+
+ switch (type) {
+ case hwmon_chip:
+ switch (attr) {
+ case hwmon_chip_update_interval:
+ return pvt_write_timeout(pvt, val);
+ }
+ break;
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_min:
+ return pvt_write_limit(pvt, ch, true, val);
+ case hwmon_temp_max:
+ return pvt_write_limit(pvt, ch, false, val);
+ }
+ break;
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_min:
+ return pvt_write_limit(pvt, PVT_VOLT + ch, true, val);
+ case hwmon_in_max:
+ return pvt_write_limit(pvt, PVT_VOLT + ch, false, val);
+ }
+ break;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static const struct hwmon_ops pvt_hwmon_ops = {
+ .is_visible = pvt_hwmon_is_visible,
+ .read = pvt_hwmon_read,
+ .read_string = pvt_hwmon_read_string,
+ .write = pvt_hwmon_write
+};
+
+static const struct hwmon_chip_info pvt_hwmon_info = {
+ .ops = &pvt_hwmon_ops,
+ .info = pvt_channel_info
+};
+
+static ssize_t pvt_hwmon_temp_trim_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pvt_hwmon *pvt = dev_get_drvdata(dev);
+ u32 data;
+
+ data = readl(pvt->regs + PVT_CTRL);
+ data = FIELD_GET(PVT_CTRL_TRIM_MASK, data);
+
+ return scnprintf(buf, PAGE_SIZE, "%lu\n", data * PVT_TRIM_STEP);
+}
+
+static ssize_t pvt_hwmon_temp_trim_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct pvt_hwmon *pvt = dev_get_drvdata(dev);
+ unsigned int temp;
+ u32 trim;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &temp);
+ if (ret)
+ return ret;
+
+ /*
+ * Serialize trim update, since a part of the register is changed and
+ * the controller is supposed to be disabled during this operation.
+ */
+ ret = mutex_lock_interruptible(&pvt->iface_mtx);
+ if (ret)
+ return ret;
+
+ trim = pvt_calc_trim(temp);
+ pvt_set_trim(pvt, trim);
+
+ mutex_unlock(&pvt->iface_mtx);
+
+ return count;
+}
+static SENSOR_DEVICE_ATTR_RW(temp1_trim, pvt_hwmon_temp_trim, 0);
+
+static struct attribute *pvt_hwmon_attrs[] = {
+ &sensor_dev_attr_temp1_trim.dev_attr.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(pvt_hwmon);
+
+static void pvt_clear_data(void *data)
+{
+ struct pvt_hwmon *pvt = data;
+#if !defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+ int idx;
+
+ for (idx = 0; idx < PVT_SENSORS_NUM; ++idx)
+ complete_all(&pvt->cache[idx].conversion);
+#endif
+
+ mutex_destroy(&pvt->iface_mtx);
+}
+
+static struct pvt_hwmon *pvt_create_data(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pvt_hwmon *pvt;
+ int ret, idx;
+
+ pvt = devm_kzalloc(dev, sizeof(*pvt), GFP_KERNEL);
+ if (!pvt)
+ return ERR_PTR(-ENOMEM);
+
+ ret = devm_add_action(dev, pvt_clear_data, pvt);
+ if (ret) {
+ dev_err(dev, "Can't add PVT data clear action\n");
+ return ERR_PTR(ret);
+ }
+
+ pvt->dev = dev;
+ pvt->sensor = PVT_SENSOR_FIRST;
+ mutex_init(&pvt->iface_mtx);
+
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+ for (idx = 0; idx < PVT_SENSORS_NUM; ++idx)
+ seqlock_init(&pvt->cache[idx].data_seqlock);
+#else
+ for (idx = 0; idx < PVT_SENSORS_NUM; ++idx)
+ init_completion(&pvt->cache[idx].conversion);
+#endif
+
+ return pvt;
+}
+
+static int pvt_request_regs(struct pvt_hwmon *pvt)
+{
+ struct platform_device *pdev = to_platform_device(pvt->dev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(pvt->dev, "Couldn't find PVT memresource\n");
+ return -EINVAL;
+ }
+
+ pvt->regs = devm_ioremap_resource(pvt->dev, res);
+ if (IS_ERR(pvt->regs)) {
+ dev_err(pvt->dev, "Couldn't map PVT registers\n");
+ return PTR_ERR(pvt->regs);
+ }
+
+ return 0;
+}
+
+static void pvt_disable_clks(void *data)
+{
+ struct pvt_hwmon *pvt = data;
+
+ clk_bulk_disable_unprepare(PVT_CLOCK_NUM, pvt->clks);
+}
+
+static int pvt_request_clks(struct pvt_hwmon *pvt)
+{
+ int ret;
+
+ pvt->clks[PVT_CLOCK_APB].id = "pclk";
+ pvt->clks[PVT_CLOCK_REF].id = "ref";
+
+ ret = devm_clk_bulk_get(pvt->dev, PVT_CLOCK_NUM, pvt->clks);
+ if (ret) {
+ dev_err(pvt->dev, "Couldn't get PVT clocks descriptors\n");
+ return ret;
+ }
+
+ ret = clk_bulk_prepare_enable(PVT_CLOCK_NUM, pvt->clks);
+ if (ret) {
+ dev_err(pvt->dev, "Couldn't enable the PVT clocks\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(pvt->dev, pvt_disable_clks, pvt);
+ if (ret) {
+ dev_err(pvt->dev, "Can't add PVT clocks disable action\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void pvt_init_iface(struct pvt_hwmon *pvt)
+{
+ unsigned int temp;
+ u32 trim;
+
+ /*
+ * Make sure all interrupts and controller are disabled so not to
+ * accidentally have ISR executed before the driver data is fully
+ * initialized. Clear the IRQ status as well.
+ */
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_ALL, PVT_INTR_ALL);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
+ readl(pvt->regs + PVT_CLR_INTR);
+ readl(pvt->regs + PVT_DATA);
+
+ /* Setup default sensor mode, timeout and temperature trim. */
+ pvt_set_mode(pvt, pvt_info[pvt->sensor].mode);
+ pvt_set_tout(pvt, PVT_TOUT_DEF);
+
+ trim = PVT_TRIM_DEF;
+ if (!of_property_read_u32(pvt->dev->of_node,
+ "baikal,pvt-temp-trim-millicelsius", &temp))
+ trim = pvt_calc_trim(temp);
+
+ pvt_set_trim(pvt, trim);
+}
+
+static int pvt_request_irq(struct pvt_hwmon *pvt)
+{
+ struct platform_device *pdev = to_platform_device(pvt->dev);
+ int ret;
+
+ pvt->irq = platform_get_irq(pdev, 0);
+ if (pvt->irq < 0)
+ return pvt->irq;
+
+ ret = devm_request_threaded_irq(pvt->dev, pvt->irq,
+ pvt_hard_isr, pvt_soft_isr,
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+ IRQF_SHARED | IRQF_TRIGGER_HIGH |
+ IRQF_ONESHOT,
+#else
+ IRQF_SHARED | IRQF_TRIGGER_HIGH,
+#endif
+ "pvt", pvt);
+ if (ret) {
+ dev_err(pvt->dev, "Couldn't request PVT IRQ\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int pvt_create_hwmon(struct pvt_hwmon *pvt)
+{
+ pvt->hwmon = devm_hwmon_device_register_with_info(pvt->dev, "pvt", pvt,
+ &pvt_hwmon_info, pvt_hwmon_groups);
+ if (IS_ERR(pvt->hwmon)) {
+ dev_err(pvt->dev, "Couldn't create hwmon device\n");
+ return PTR_ERR(pvt->hwmon);
+ }
+
+ return 0;
+}
+
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+
+static void pvt_disable_iface(void *data)
+{
+ struct pvt_hwmon *pvt = data;
+
+ mutex_lock(&pvt->iface_mtx);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID,
+ PVT_INTR_DVALID);
+ mutex_unlock(&pvt->iface_mtx);
+}
+
+static int pvt_enable_iface(struct pvt_hwmon *pvt)
+{
+ int ret;
+
+ ret = devm_add_action(pvt->dev, pvt_disable_iface, pvt);
+ if (ret) {
+ dev_err(pvt->dev, "Can't add PVT disable interface action\n");
+ return ret;
+ }
+
+ /*
+ * Enable sensors data conversion and IRQ. We need to lock the
+ * interface mutex since hwmon has just been created and the
+ * corresponding sysfs files are accessible from user-space,
+ * which theoretically may cause races.
+ */
+ mutex_lock(&pvt->iface_mtx);
+ pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_DVALID, 0);
+ pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, PVT_CTRL_EN);
+ mutex_unlock(&pvt->iface_mtx);
+
+ return 0;
+}
+
+#else /* !CONFIG_SENSORS_BT1_PVT_ALARMS */
+
+static int pvt_enable_iface(struct pvt_hwmon *pvt)
+{
+ return 0;
+}
+
+#endif /* !CONFIG_SENSORS_BT1_PVT_ALARMS */
+
+static int pvt_probe(struct platform_device *pdev)
+{
+ struct pvt_hwmon *pvt;
+ int ret;
+
+ pvt = pvt_create_data(pdev);
+ if (IS_ERR(pvt))
+ return PTR_ERR(pvt);
+
+ ret = pvt_request_regs(pvt);
+ if (ret)
+ return ret;
+
+ ret = pvt_request_clks(pvt);
+ if (ret)
+ return ret;
+
+ pvt_init_iface(pvt);
+
+ ret = pvt_request_irq(pvt);
+ if (ret)
+ return ret;
+
+ ret = pvt_create_hwmon(pvt);
+ if (ret)
+ return ret;
+
+ ret = pvt_enable_iface(pvt);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct of_device_id pvt_of_match[] = {
+ { .compatible = "baikal,bt1-pvt" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pvt_of_match);
+
+static struct platform_driver pvt_driver = {
+ .probe = pvt_probe,
+ .driver = {
+ .name = "bt1-pvt",
+ .of_match_table = pvt_of_match
+ }
+};
+module_platform_driver(pvt_driver);
+
+MODULE_AUTHOR("Maxim Kaurkin <maxim.kaurkin@baikalelectronics.ru>");
+MODULE_DESCRIPTION("Baikal-T1 PVT driver");
+MODULE_LICENSE("GPL v2");
new file mode 100644
@@ -0,0 +1,244 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
+ *
+ * Baikal-T1 Process, Voltage, Temperature sensor driver
+ */
+#ifndef __HWMON_BT1_PVT_H__
+#define __HWMON_BT1_PVT_H__
+
+#include <linux/completion.h>
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/seqlock.h>
+
+/* Baikal-T1 PVT registers and their bitfields */
+#define PVT_CTRL 0x00
+#define PVT_CTRL_EN BIT(0)
+#define PVT_CTRL_MODE_FLD 1
+#define PVT_CTRL_MODE_MASK GENMASK(3, PVT_CTRL_MODE_FLD)
+#define PVT_CTRL_MODE_TEMP 0x0
+#define PVT_CTRL_MODE_VOLT 0x1
+#define PVT_CTRL_MODE_LVT 0x2
+#define PVT_CTRL_MODE_HVT 0x4
+#define PVT_CTRL_MODE_SVT 0x6
+#define PVT_CTRL_TRIM_FLD 4
+#define PVT_CTRL_TRIM_MASK GENMASK(8, PVT_CTRL_TRIM_FLD)
+#define PVT_DATA 0x04
+#define PVT_DATA_VALID BIT(10)
+#define PVT_DATA_DATA_FLD 0
+#define PVT_DATA_DATA_MASK GENMASK(9, PVT_DATA_DATA_FLD)
+#define PVT_TTHRES 0x08
+#define PVT_VTHRES 0x0C
+#define PVT_LTHRES 0x10
+#define PVT_HTHRES 0x14
+#define PVT_STHRES 0x18
+#define PVT_THRES_LO_FLD 0
+#define PVT_THRES_LO_MASK GENMASK(9, PVT_THRES_LO_FLD)
+#define PVT_THRES_HI_FLD 10
+#define PVT_THRES_HI_MASK GENMASK(19, PVT_THRES_HI_FLD)
+#define PVT_TTIMEOUT 0x1C
+#define PVT_INTR_STAT 0x20
+#define PVT_INTR_MASK 0x24
+#define PVT_RAW_INTR_STAT 0x28
+#define PVT_INTR_DVALID BIT(0)
+#define PVT_INTR_TTHRES_LO BIT(1)
+#define PVT_INTR_TTHRES_HI BIT(2)
+#define PVT_INTR_VTHRES_LO BIT(3)
+#define PVT_INTR_VTHRES_HI BIT(4)
+#define PVT_INTR_LTHRES_LO BIT(5)
+#define PVT_INTR_LTHRES_HI BIT(6)
+#define PVT_INTR_HTHRES_LO BIT(7)
+#define PVT_INTR_HTHRES_HI BIT(8)
+#define PVT_INTR_STHRES_LO BIT(9)
+#define PVT_INTR_STHRES_HI BIT(10)
+#define PVT_INTR_ALL GENMASK(10, 0)
+#define PVT_CLR_INTR 0x2C
+
+/*
+ * PVT sensors-related limits and default values
+ * @PVT_TEMP_MIN: Minimal temperature in millidegrees of Celsius.
+ * @PVT_TEMP_MAX: Maximal temperature in millidegrees of Celsius.
+ * @PVT_TEMP_CHS: Number of temperature hwmon channels.
+ * @PVT_VOLT_MIN: Minimal voltage in mV.
+ * @PVT_VOLT_MAX: Maximal voltage in mV.
+ * @PVT_VOLT_CHS: Number of voltage hwmon channels.
+ * @PVT_DATA_MIN: Minimal PVT raw data value.
+ * @PVT_DATA_MAX: Maximal PVT raw data value.
+ * @PVT_TRIM_MIN: Minimal temperature sensor trim value.
+ * @PVT_TRIM_MAX: Maximal temperature sensor trim value.
+ * @PVT_TRIM_DEF: Default temperature sensor trim value (set a proper value
+ * when one is determined for Baikal-T1 SoC).
+ * @PVT_TRIM_TEMP: Maximum temperature encoded by the trim factor.
+ * @PVT_TRIM_STEP: Temperature stride corresponding to the trim value.
+ * @PVT_TOUT_MIN: Minimal timeout between samples in nanoseconds.
+ * @PVT_TOUT_DEF: Default data measurements timeout. In case if alarms are
+ * activated the PVT IRQ is enabled to be raised after each
+ * conversion in order to have the thresholds checked and the
+ * converted value cached. Too frequent conversions may cause
+ * the system CPU overload. Lets set the 50ms delay between
+ * them by default to prevent this.
+ */
+#define PVT_TEMP_MIN -48380L
+#define PVT_TEMP_MAX 147438L
+#define PVT_TEMP_CHS 1
+#define PVT_VOLT_MIN 620L
+#define PVT_VOLT_MAX 1168L
+#define PVT_VOLT_CHS 4
+#define PVT_DATA_MIN 0
+#define PVT_DATA_MAX (PVT_DATA_DATA_MASK >> PVT_DATA_DATA_FLD)
+#define PVT_TRIM_MIN 0
+#define PVT_TRIM_MAX (PVT_CTRL_TRIM_MASK >> PVT_CTRL_TRIM_FLD)
+#define PVT_TRIM_TEMP 7130
+#define PVT_TRIM_STEP (PVT_TRIM_TEMP / PVT_TRIM_MAX)
+#define PVT_TRIM_DEF 0
+#define PVT_TOUT_MIN (NSEC_PER_SEC / 3000)
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+# define PVT_TOUT_DEF 60000
+#else
+# define PVT_TOUT_DEF 0
+#endif
+
+/*
+ * enum pvt_sensor_type - Baikal-T1 PVT sensor types (correspond to each PVT
+ * sampling mode)
+ * @PVT_SENSOR*: helpers to traverse the sensors in loops.
+ * @PVT_TEMP: PVT Temperature sensor.
+ * @PVT_VOLT: PVT Voltage sensor.
+ * @PVT_LVT: PVT Low-Voltage threshold sensor.
+ * @PVT_HVT: PVT High-Voltage threshold sensor.
+ * @PVT_SVT: PVT Standard-Voltage threshold sensor.
+ */
+enum pvt_sensor_type {
+ PVT_SENSOR_FIRST,
+ PVT_TEMP = PVT_SENSOR_FIRST,
+ PVT_VOLT,
+ PVT_LVT,
+ PVT_HVT,
+ PVT_SVT,
+ PVT_SENSOR_LAST = PVT_SVT,
+ PVT_SENSORS_NUM
+};
+
+/*
+ * enum pvt_clock_type - Baikal-T1 PVT clocks.
+ * @PVT_CLOCK_APB: APB clock.
+ * @PVT_CLOCK_REF: PVT reference clock.
+ */
+enum pvt_clock_type {
+ PVT_CLOCK_APB,
+ PVT_CLOCK_REF,
+ PVT_CLOCK_NUM
+};
+
+/*
+ * struct pvt_sensor_info - Baikal-T1 PVT sensor informational structure
+ * @channel: Sensor channel ID.
+ * @label: hwmon sensor label.
+ * @mode: PVT mode corresponding to the channel.
+ * @thres_base: upper and lower threshold values of the sensor.
+ * @thres_sts_lo: low threshold status bitfield.
+ * @thres_sts_hi: high threshold status bitfield.
+ * @type: Sensor type.
+ * @attr_min_alarm: Min alarm attribute ID.
+ * @attr_min_alarm: Max alarm attribute ID.
+ */
+struct pvt_sensor_info {
+ int channel;
+ const char *label;
+ u32 mode;
+ unsigned long thres_base;
+ u32 thres_sts_lo;
+ u32 thres_sts_hi;
+ enum hwmon_sensor_types type;
+ u32 attr_min_alarm;
+ u32 attr_max_alarm;
+};
+
+#define PVT_SENSOR_INFO(_ch, _label, _type, _mode, _thres) \
+ { \
+ .channel = _ch, \
+ .label = _label, \
+ .mode = PVT_CTRL_MODE_ ##_mode, \
+ .thres_base = PVT_ ##_thres, \
+ .thres_sts_lo = PVT_INTR_ ##_thres## _LO, \
+ .thres_sts_hi = PVT_INTR_ ##_thres## _HI, \
+ .type = _type, \
+ .attr_min_alarm = _type## _min, \
+ .attr_max_alarm = _type## _max, \
+ }
+
+/*
+ * struct pvt_cache - PVT sensors data cache
+ * @data: data cache in raw format.
+ * @thres_sts_lo: low threshold status saved on the previous data conversion.
+ * @thres_sts_hi: high threshold status saved on the previous data conversion.
+ * @data_seqlock: cached data seq-lock.
+ * @conversion: data conversion completion.
+ */
+struct pvt_cache {
+ u32 data;
+#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
+ seqlock_t data_seqlock;
+ u32 thres_sts_lo;
+ u32 thres_sts_hi;
+#else
+ struct completion conversion;
+#endif
+};
+
+/*
+ * struct pvt_hwmon - Baikal-T1 PVT private data
+ * @dev: device structure of the PVT platform device.
+ * @hwmon: hwmon device structure.
+ * @regs: pointer to the Baikal-T1 PVT registers region.
+ * @irq: PVT events IRQ number.
+ * @clks: Array of the PVT clocks descriptor (APB/ref clocks).
+ * @ref_clk: Pointer to the reference clocks descriptor.
+ * @iface_mtx: Generic interface mutex (used to lock the alarm registers
+ * when the alarms enabled, or the data conversion interface
+ * if alarms are disabled).
+ * @sensor: current PVT sensor the data conversion is being performed for.
+ * @cache: data cache descriptor.
+ */
+struct pvt_hwmon {
+ struct device *dev;
+ struct device *hwmon;
+
+ void __iomem *regs;
+ int irq;
+
+ struct clk_bulk_data clks[PVT_CLOCK_NUM];
+
+ struct mutex iface_mtx;
+ enum pvt_sensor_type sensor;
+ struct pvt_cache cache[PVT_SENSORS_NUM];
+};
+
+/*
+ * struct pvt_poly_term - a term descriptor of the PVT data translation
+ * polynomial
+ * @deg: degree of the term.
+ * @coef: multiplication factor of the term.
+ * @divider: distributed divider per each degree.
+ * @divider_leftover: divider leftover, which couldn't be redistributed.
+ */
+struct pvt_poly_term {
+ unsigned int deg;
+ long coef;
+ long divider;
+ long divider_leftover;
+};
+
+/*
+ * struct pvt_poly - PVT data translation polynomial descriptor
+ * @total_divider: total data divider.
+ * @terms: polynomial terms up to a free one.
+ */
+struct pvt_poly {
+ long total_divider;
+ struct pvt_poly_term terms[];
+};
+
+#endif /* __HWMON_BT1_PVT_H__ */