drivers/timer/dw-apb-timer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Designware APB Timer driver
   4  *
   5  * Copyright (C) 2018 Marek Vasut <marex@denx.de>
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <clk.h>
  11 #include <timer.h>
  12
  13 #include <asm/io.h>
  14 #include <asm/arch/timer.h>
  15
  16 #define DW_APB_LOAD_VAL         0x0
  17 #define DW_APB_CURR_VAL         0x4
  18 #define DW_APB_CTRL             0x8
  19
  20 DECLARE_GLOBAL_DATA_PTR;
  21
  22 struct dw_apb_timer_priv {
  23         fdt_addr_t      regs;
  24 };
  25
  26 static int dw_apb_timer_get_count(struct udevice *dev, u64 *count)
  27 {
  28         struct dw_apb_timer_priv *priv = dev_get_priv(dev);
  29
  30         /*
  31          * The DW APB counter counts down, but this function
  32          * requires the count to be incrementing. Invert the
  33          * result.
  34          */
  35         *count = ~readl(priv->regs + DW_APB_CURR_VAL);
  36
  37         return 0;
  38 }
  39
  40 static int dw_apb_timer_probe(struct udevice *dev)
  41 {
  42         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  43         struct dw_apb_timer_priv *priv = dev_get_priv(dev);
  44         struct clk clk;
  45         int ret;
  46
  47         ret = clk_get_by_index(dev, 0, &clk);
  48         if (ret)
  49                 return ret;
  50
  51         uc_priv->clock_rate = clk_get_rate(&clk);
  52
  53         clk_free(&clk);
  54
  55         /* init timer */
  56         writel(0xffffffff, priv->regs + DW_APB_LOAD_VAL);
  57         writel(0xffffffff, priv->regs + DW_APB_CURR_VAL);
  58         setbits_le32(priv->regs + DW_APB_CTRL, 0x3);
  59
  60         return 0;
  61 }
  62
  63 static int dw_apb_timer_ofdata_to_platdata(struct udevice *dev)
  64 {
  65         struct dw_apb_timer_priv *priv = dev_get_priv(dev);
  66
  67         priv->regs = dev_read_addr(dev);
  68
  69         return 0;
  70 }
  71
  72 static const struct timer_ops dw_apb_timer_ops = {
  73         .get_count      = dw_apb_timer_get_count,
  74 };
  75
  76 static const struct udevice_id dw_apb_timer_ids[] = {
  77         { .compatible = "snps,dw-apb-timer" },
  78         {}
  79 };
  80
  81 U_BOOT_DRIVER(dw_apb_timer) = {
  82         .name           = "dw_apb_timer",
  83         .id             = UCLASS_TIMER,
  84         .ops            = &dw_apb_timer_ops,
  85         .probe          = dw_apb_timer_probe,
  86         .of_match       = dw_apb_timer_ids,
  87         .ofdata_to_platdata = dw_apb_timer_ofdata_to_platdata,
  88         .priv_auto_alloc_size = sizeof(struct dw_apb_timer_priv),
  89 };