diff options
| -rw-r--r-- | drivers/hwmon/bt1-pvt.c | 85 | ||||
| -rw-r--r-- | drivers/hwmon/bt1-pvt.h | 3 |
2 files changed, 49 insertions, 39 deletions
diff --git a/drivers/hwmon/bt1-pvt.c b/drivers/hwmon/bt1-pvt.c index f4b7353c078a..2600426a3b21 100644 --- a/drivers/hwmon/bt1-pvt.c +++ b/drivers/hwmon/bt1-pvt.c @@ -655,44 +655,16 @@ static int pvt_write_trim(struct pvt_hwmon *pvt, long val) 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; + int ret; - /* - * 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 + 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(kt); + *val = ktime_to_ms(pvt->timeout); + + mutex_unlock(&pvt->iface_mtx); return 0; } @@ -700,7 +672,7 @@ static int pvt_read_timeout(struct pvt_hwmon *pvt, long *val) static int pvt_write_timeout(struct pvt_hwmon *pvt, long val) { unsigned long rate; - ktime_t kt; + ktime_t kt, cache; u32 data; int ret; @@ -713,7 +685,7 @@ static int pvt_write_timeout(struct pvt_hwmon *pvt, long val) * between all available sensors to have the requested delay * applicable to each individual sensor. */ - kt = ms_to_ktime(val); + cache = kt = ms_to_ktime(val); #if defined(CONFIG_SENSORS_BT1_PVT_ALARMS) kt = ktime_divns(kt, PVT_SENSORS_NUM); #endif @@ -742,6 +714,7 @@ static int pvt_write_timeout(struct pvt_hwmon *pvt, long val) return ret; pvt_set_tout(pvt, data); + pvt->timeout = cache; mutex_unlock(&pvt->iface_mtx); @@ -1018,10 +991,17 @@ static int pvt_check_pwr(struct pvt_hwmon *pvt) return ret; } -static void pvt_init_iface(struct pvt_hwmon *pvt) +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 @@ -1036,12 +1016,37 @@ static void pvt_init_iface(struct pvt_hwmon *pvt) 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) @@ -1149,7 +1154,9 @@ static int pvt_probe(struct platform_device *pdev) if (ret) return ret; - pvt_init_iface(pvt); + ret = pvt_init_iface(pvt); + if (ret) + return ret; ret = pvt_request_irq(pvt); if (ret) diff --git a/drivers/hwmon/bt1-pvt.h b/drivers/hwmon/bt1-pvt.h index 5eac73e94885..93b8dd5e7c94 100644 --- a/drivers/hwmon/bt1-pvt.h +++ b/drivers/hwmon/bt1-pvt.h @@ -10,6 +10,7 @@ #include <linux/completion.h> #include <linux/hwmon.h> #include <linux/kernel.h> +#include <linux/ktime.h> #include <linux/mutex.h> #include <linux/seqlock.h> @@ -201,6 +202,7 @@ struct pvt_cache { * if alarms are disabled). * @sensor: current PVT sensor the data conversion is being performed for. * @cache: data cache descriptor. + * @timeout: conversion timeout cache. */ struct pvt_hwmon { struct device *dev; @@ -214,6 +216,7 @@ struct pvt_hwmon { struct mutex iface_mtx; enum pvt_sensor_type sensor; struct pvt_cache cache[PVT_SENSORS_NUM]; + ktime_t timeout; }; /* |