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linux-sg2042/drivers/hwmon/bt1-pvt.c

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// 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/delay.h>
#include <linux/device.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.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].
*/
static const struct pvt_poly __maybe_unused 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}
}
};
static const 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.
*/
static const struct pvt_poly __maybe_unused poly_volt_to_N = {
.total_divider = 10,
.terms = {
{1, 18658, 1000, 1},
{0, -11572, 1, 1}
}
};
static const 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(long 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;
}
static inline umode_t pvt_limit_is_visible(enum pvt_sensor_type type)
{
return 0644;
}
static 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_T_OFFSET),
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
static inline umode_t pvt_limit_is_visible(enum pvt_sensor_type type)
{
return 0;
}
static 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];
unsigned long timeout;
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 with timeout since in case if the sensor is suddenly powered
* down the request won't be completed and the caller will hang up on
* this procedure until the power is back up again. Multiply the
* timeout by the factor of two to prevent a false timeout.
*/
timeout = 2 * usecs_to_jiffies(ktime_to_us(pvt->timeout));
ret = wait_for_completion_timeout(&cache->conversion, timeout);
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 (!ret)
return -ETIMEDOUT;
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_T_OFFSET),
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);
case hwmon_temp_offset:
return 0644;
}
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_trim(struct pvt_hwmon *pvt, long *val)
{
u32 data;
data = readl(pvt->regs + PVT_CTRL);
*val = FIELD_GET(PVT_CTRL_TRIM_MASK, data) * PVT_TRIM_STEP;
return 0;
}
static int pvt_write_trim(struct pvt_hwmon *pvt, long val)
{
u32 trim;
int 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(val);
pvt_set_trim(pvt, trim);
mutex_unlock(&pvt->iface_mtx);
return 0;
}
static int pvt_read_timeout(struct pvt_hwmon *pvt, long *val)
{
int ret;
ret = mutex_lock_interruptible(&pvt->iface_mtx);
if (ret)
return ret;
/* Return the result in msec as hwmon sysfs interface requires. */
*val = ktime_to_ms(pvt->timeout);
mutex_unlock(&pvt->iface_mtx);
return 0;
}
static int pvt_write_timeout(struct pvt_hwmon *pvt, long val)
{
unsigned long rate;
ktime_t kt, cache;
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.
*/
cache = 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);
pvt->timeout = cache;
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);
case hwmon_temp_offset:
return pvt_read_trim(pvt, 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;
}
static 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);
case hwmon_temp_offset:
return pvt_write_trim(pvt, 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 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 int pvt_check_pwr(struct pvt_hwmon *pvt)
{
unsigned long tout;
int ret = 0;
u32 data;
/*
* Test out the sensor conversion functionality. If it is not done on
* time then the domain must have been unpowered and we won't be able
* to use the device later in this driver.
* Note If the power source is lost during the normal driver work the
* data read procedure will either return -ETIMEDOUT (for the
* alarm-less driver configuration) or just stop the repeated
* conversion. In the later case alas we won't be able to detect the
* problem.
*/
pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_ALL, PVT_INTR_ALL);
pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, PVT_CTRL_EN);
pvt_set_tout(pvt, 0);
readl(pvt->regs + PVT_DATA);
tout = PVT_TOUT_MIN / NSEC_PER_USEC;
usleep_range(tout, 2 * tout);
data = readl(pvt->regs + PVT_DATA);
if (!(data & PVT_DATA_VALID)) {
ret = -ENODEV;
dev_err(pvt->dev, "Sensor is powered down\n");
}
pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);
return ret;
}
static int pvt_init_iface(struct pvt_hwmon *pvt)
{
unsigned long rate;
u32 trim, temp;
rate = clk_get_rate(pvt->clks[PVT_CLOCK_REF].clk);
if (!rate) {
dev_err(pvt->dev, "Invalid reference clock rate\n");
return -ENODEV;
}
/*
* 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);
/*
* Preserve the current ref-clock based delay (Ttotal) between the
* sensors data samples in the driver data so not to recalculate it
* each time on the data requests and timeout reads. It consists of the
* delay introduced by the internal ref-clock timer (N / Fclk) and the
* constant timeout caused by each conversion latency (Tmin):
* Ttotal = N / Fclk + Tmin
* If alarms are enabled the sensors are polled one after another and
* in order to get the next measurement of a particular sensor the
* caller will have to wait for at most until all the others are
* polled. In that case the formulae will look a bit different:
* Ttotal = 5 * (N / Fclk + Tmin)
*/
#if defined(CONFIG_SENSORS_BT1_PVT_ALARMS)
pvt->timeout = ktime_set(PVT_SENSORS_NUM * PVT_TOUT_DEF, 0);
pvt->timeout = ktime_divns(pvt->timeout, rate);
pvt->timeout = ktime_add_ns(pvt->timeout, PVT_SENSORS_NUM * PVT_TOUT_MIN);
#else
pvt->timeout = ktime_set(PVT_TOUT_DEF, 0);
pvt->timeout = ktime_divns(pvt->timeout, rate);
pvt->timeout = ktime_add_ns(pvt->timeout, PVT_TOUT_MIN);
#endif
trim = PVT_TRIM_DEF;
if (!of_property_read_u32(pvt->dev->of_node,
"baikal,pvt-temp-offset-millicelsius", &temp))
trim = pvt_calc_trim(temp);
pvt_set_trim(pvt, trim);
return 0;
}
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, NULL);
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;
ret = pvt_check_pwr(pvt);
if (ret)
return ret;
ret = pvt_init_iface(pvt);
if (ret)
return ret;
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");
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