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 struct dw_apb_timer_priv {
  21         fdt_addr_t      regs;
  22 };
  23
  24 static int dw_apb_timer_get_count(struct udevice *dev, u64 *count)
  25 {
  26         struct dw_apb_timer_priv *priv = dev_get_priv(dev);
  27
  28         /*
  29          * The DW APB counter counts down, but this function
  30          * requires the count to be incrementing. Invert the
  31          * result.
  32          */
  33         *count = timer_conv_64(~readl(priv->regs + DW_APB_CURR_VAL));
  34
  35         return 0;
  36 }
  37
  38 static int dw_apb_timer_probe(struct udevice *dev)
  39 {
  40         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  41         struct dw_apb_timer_priv *priv = dev_get_priv(dev);
  42         struct clk clk;
  43         int ret;
  44
  45         ret = clk_get_by_index(dev, 0, &clk);
  46         if (ret)
  47                 return ret;
  48
  49         uc_priv->clock_rate = clk_get_rate(&clk);
  50
  51         clk_free(&clk);
  52
  53         /* init timer */
  54         writel(0xffffffff, priv->regs + DW_APB_LOAD_VAL);
  55         writel(0xffffffff, priv->regs + DW_APB_CURR_VAL);
  56         setbits_le32(priv->regs + DW_APB_CTRL, 0x3);
  57
  58         return 0;
  59 }
  60
  61 static int dw_apb_timer_ofdata_to_platdata(struct udevice *dev)
  62 {
  63         struct dw_apb_timer_priv *priv = dev_get_priv(dev);
  64
  65         priv->regs = dev_read_addr(dev);
  66
  67         return 0;
  68 }
  69
  70 static const struct timer_ops dw_apb_timer_ops = {
  71         .get_count      = dw_apb_timer_get_count,
  72 };
  73
  74 static const struct udevice_id dw_apb_timer_ids[] = {
  75         { .compatible = "snps,dw-apb-timer" },
  76         {}
  77 };
  78
  79 U_BOOT_DRIVER(dw_apb_timer) = {
  80         .name           = "dw_apb_timer",
  81         .id             = UCLASS_TIMER,
  82         .ops            = &dw_apb_timer_ops,
  83         .probe          = dw_apb_timer_probe,
  84         .of_match       = dw_apb_timer_ids,
  85         .ofdata_to_platdata = dw_apb_timer_ofdata_to_platdata,
  86         .priv_auto_alloc_size = sizeof(struct dw_apb_timer_priv),
  87 };