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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright(c) 2023 Intel Corporation */3 4#include <linux/delay.h>5#include <linux/dev_printk.h>6#include <linux/export.h>7#include <linux/math.h>8#include <linux/minmax.h>9#include <linux/time64.h>10#include <linux/types.h>11#include <linux/units.h>12#include <asm/errno.h>13#include "adf_admin.h"14#include "adf_accel_devices.h"15#include "adf_clock.h"16#include "adf_common_drv.h"17 18#define MEASURE_CLOCK_RETRIES 1019#define MEASURE_CLOCK_DELAY_US 1000020#define ME_CLK_DIVIDER 1621#define MEASURE_CLOCK_DELTA_THRESHOLD_US 10022 23static inline u64 timespec_to_us(const struct timespec64 *ts)24{25 return (u64)DIV_ROUND_CLOSEST_ULL(timespec64_to_ns(ts), NSEC_PER_USEC);26}27 28static inline u64 timespec_to_ms(const struct timespec64 *ts)29{30 return (u64)DIV_ROUND_CLOSEST_ULL(timespec64_to_ns(ts), NSEC_PER_MSEC);31}32 33u64 adf_clock_get_current_time(void)34{35 struct timespec64 ts;36 37 ktime_get_real_ts64(&ts);38 return timespec_to_ms(&ts);39}40 41static int measure_clock(struct adf_accel_dev *accel_dev, u32 *frequency)42{43 struct timespec64 ts1, ts2, ts3, ts4;44 u64 timestamp1, timestamp2, temp;45 u32 delta_us, tries;46 int ret;47 48 tries = MEASURE_CLOCK_RETRIES;49 do {50 ktime_get_real_ts64(&ts1);51 ret = adf_get_fw_timestamp(accel_dev, ×tamp1);52 if (ret) {53 dev_err(&GET_DEV(accel_dev),54 "Failed to get fw timestamp\n");55 return ret;56 }57 ktime_get_real_ts64(&ts2);58 delta_us = timespec_to_us(&ts2) - timespec_to_us(&ts1);59 } while (delta_us > MEASURE_CLOCK_DELTA_THRESHOLD_US && --tries);60 61 if (!tries) {62 dev_err(&GET_DEV(accel_dev), "Excessive clock measure delay\n");63 return -ETIMEDOUT;64 }65 66 fsleep(MEASURE_CLOCK_DELAY_US);67 68 tries = MEASURE_CLOCK_RETRIES;69 do {70 ktime_get_real_ts64(&ts3);71 if (adf_get_fw_timestamp(accel_dev, ×tamp2)) {72 dev_err(&GET_DEV(accel_dev),73 "Failed to get fw timestamp\n");74 return -EIO;75 }76 ktime_get_real_ts64(&ts4);77 delta_us = timespec_to_us(&ts4) - timespec_to_us(&ts3);78 } while (delta_us > MEASURE_CLOCK_DELTA_THRESHOLD_US && --tries);79 80 if (!tries) {81 dev_err(&GET_DEV(accel_dev), "Excessive clock measure delay\n");82 return -ETIMEDOUT;83 }84 85 delta_us = timespec_to_us(&ts3) - timespec_to_us(&ts1);86 if (!delta_us)87 return -EINVAL;88 89 temp = (timestamp2 - timestamp1) * ME_CLK_DIVIDER * 10;90 temp = DIV_ROUND_CLOSEST_ULL(temp, delta_us);91 /*92 * Enclose the division to allow the preprocessor to precalculate it,93 * and avoid promoting r-value to 64-bit before division.94 */95 *frequency = temp * (HZ_PER_MHZ / 10);96 97 return 0;98}99 100/**101 * adf_dev_measure_clock() - measures device clock frequency102 * @accel_dev: Pointer to acceleration device.103 * @frequency: Pointer to variable where result will be stored104 * @min: Minimal allowed frequency value105 * @max: Maximal allowed frequency value106 *107 * If the measurement result will go beyond the min/max thresholds the value108 * will take the value of the crossed threshold.109 *110 * This algorithm compares the device firmware timestamp with the kernel111 * timestamp. So we can't expect too high accuracy from this measurement.112 *113 * Return:114 * * 0 - measurement succeed115 * * -ETIMEDOUT - measurement failed116 */117int adf_dev_measure_clock(struct adf_accel_dev *accel_dev,118 u32 *frequency, u32 min, u32 max)119{120 int ret;121 u32 freq;122 123 ret = measure_clock(accel_dev, &freq);124 if (ret)125 return ret;126 127 *frequency = clamp(freq, min, max);128 129 if (*frequency != freq)130 dev_warn(&GET_DEV(accel_dev),131 "Measured clock %d Hz is out of range, assuming %d\n",132 freq, *frequency);133 return 0;134}135EXPORT_SYMBOL_GPL(adf_dev_measure_clock);136