1 /* 2 * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw> 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <errno.h> 10 #include <timer.h> 11 12 DECLARE_GLOBAL_DATA_PTR; 13 14 /* 15 * Implement a timer uclass to work with lib/time.c. The timer is usually 16 * a 32/64 bits free-running up counter. The get_rate() method is used to get 17 * the input clock frequency of the timer. The get_count() method is used 18 * to get the current 64 bits count value. If the hardware is counting down, 19 * the value should be inversed inside the method. There may be no real 20 * tick, and no timer interrupt. 21 */ 22 23 int timer_get_count(struct udevice *dev, u64 *count) 24 { 25 const struct timer_ops *ops = device_get_ops(dev); 26 27 if (!ops->get_count) 28 return -ENOSYS; 29 30 return ops->get_count(dev, count); 31 } 32 33 unsigned long timer_get_rate(struct udevice *dev) 34 { 35 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); 36 37 return uc_priv->clock_rate; 38 } 39 40 static int timer_pre_probe(struct udevice *dev) 41 { 42 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); 43 44 uc_priv->clock_rate = fdtdec_get_int(gd->fdt_blob, dev->of_offset, 45 "clock-frequency", 0); 46 47 return 0; 48 } 49 50 u64 timer_conv_64(u32 count) 51 { 52 /* increment tbh if tbl has rolled over */ 53 if (count < gd->timebase_l) 54 gd->timebase_h++; 55 gd->timebase_l = count; 56 return ((u64)gd->timebase_h << 32) | gd->timebase_l; 57 } 58 59 UCLASS_DRIVER(timer) = { 60 .id = UCLASS_TIMER, 61 .name = "timer", 62 .pre_probe = timer_pre_probe, 63 .per_device_auto_alloc_size = sizeof(struct timer_dev_priv), 64 }; 65