drivers/timer/riscv_aclint_timer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2020, Sean Anderson <seanga2@gmail.com>
   4  * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
   5  */
   6
   7 #include <common.h>
   8 #include <clk.h>
   9 #include <dm.h>
  10 #include <timer.h>
  11 #include <asm/io.h>
  12 #include <dm/device-internal.h>
  13 #include <linux/err.h>
  14
  15 #define CLINT_MTIME_OFFSET              0xbff8
  16 #define ACLINT_MTIME_OFFSET             0
  17
  18 /* mtime register */
  19 #define MTIME_REG(base, offset)         ((ulong)(base) + (offset))
  20
  21 static u64 notrace riscv_aclint_timer_get_count(struct udevice *dev)
  22 {
  23         return readq((void __iomem *)MTIME_REG(dev_get_priv(dev),
  24                                                dev_get_driver_data(dev)));
  25 }
  26
  27 #if CONFIG_IS_ENABLED(RISCV_MMODE) && IS_ENABLED(CONFIG_TIMER_EARLY)
  28 /**
  29  * timer_early_get_rate() - Get the timer rate before driver model
  30  */
  31 unsigned long notrace timer_early_get_rate(void)
  32 {
  33         return RISCV_MMODE_TIMER_FREQ;
  34 }
  35
  36 /**
  37  * timer_early_get_count() - Get the timer count before driver model
  38  *
  39  */
  40 u64 notrace timer_early_get_count(void)
  41 {
  42         return readq((void __iomem *)MTIME_REG(RISCV_MMODE_TIMERBASE,
  43                                                RISCV_MMODE_TIMEROFF));
  44 }
  45 #endif
  46
  47 static const struct timer_ops riscv_aclint_timer_ops = {
  48         .get_count = riscv_aclint_timer_get_count,
  49 };
  50
  51 static int riscv_aclint_timer_probe(struct udevice *dev)
  52 {
  53         dev_set_priv(dev, dev_read_addr_ptr(dev));
  54         if (!dev_get_priv(dev))
  55                 return -EINVAL;
  56
  57         return timer_timebase_fallback(dev);
  58 }
  59
  60 static const struct udevice_id riscv_aclint_timer_ids[] = {
  61         { .compatible = "riscv,clint0", .data = CLINT_MTIME_OFFSET },
  62         { .compatible = "sifive,clint0", .data = CLINT_MTIME_OFFSET },
  63         { .compatible = "riscv,aclint-mtimer", .data = ACLINT_MTIME_OFFSET },
  64         { }
  65 };
  66
  67 U_BOOT_DRIVER(riscv_aclint_timer) = {
  68         .name           = "riscv_aclint_timer",
  69         .id             = UCLASS_TIMER,
  70         .of_match       = riscv_aclint_timer_ids,
  71         .probe          = riscv_aclint_timer_probe,
  72         .ops            = &riscv_aclint_timer_ops,
  73         .flags          = DM_FLAG_PRE_RELOC,
  74 };