// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC * * Authors: * Maxim Kaurkin * Serge Semin * * Baikal-T1 Process, Voltage, Temperature sensor driver */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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]; 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_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 "); MODULE_DESCRIPTION("Baikal-T1 PVT driver"); MODULE_LICENSE("GPL v2");