git.sur5r.net Git - u-boot/blob - drivers/timer/ast_timer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2016 Google Inc.
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <errno.h>
   9 #include <timer.h>
  10 #include <asm/io.h>
  11 #include <asm/arch/timer.h>
  12
  13 #define AST_TICK_TIMER  1
  14 #define AST_TMC_RELOAD_VAL  0xffffffff
  15
  16 struct ast_timer_priv {
  17         struct ast_timer *regs;
  18         struct ast_timer_counter *tmc;
  19 };
  20
  21 static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer,
  22                                                        int n)
  23 {
  24         if (n > 3)
  25                 return &timer->timers2[n - 4];
  26         else
  27                 return &timer->timers1[n - 1];
  28 }
  29
  30 static int ast_timer_probe(struct udevice *dev)
  31 {
  32         struct ast_timer_priv *priv = dev_get_priv(dev);
  33         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  34
  35         writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val);
  36
  37         /*
  38          * Stop the timer. This will also load reload_val into
  39          * the status register.
  40          */
  41         clrbits_le32(&priv->regs->ctrl1,
  42                      AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
  43         /* Start the timer from the fixed 1MHz clock. */
  44         setbits_le32(&priv->regs->ctrl1,
  45                      (AST_TMC_EN | AST_TMC_1MHZ) <<
  46                      AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
  47
  48         uc_priv->clock_rate = AST_TMC_RATE;
  49
  50         return 0;
  51 }
  52
  53 static int ast_timer_get_count(struct udevice *dev, u64 *count)
  54 {
  55         struct ast_timer_priv *priv = dev_get_priv(dev);
  56
  57         *count = AST_TMC_RELOAD_VAL - readl(&priv->tmc->status);
  58
  59         return 0;
  60 }
  61
  62 static int ast_timer_ofdata_to_platdata(struct udevice *dev)
  63 {
  64         struct ast_timer_priv *priv = dev_get_priv(dev);
  65
  66         priv->regs = devfdt_get_addr_ptr(dev);
  67         if (IS_ERR(priv->regs))
  68                 return PTR_ERR(priv->regs);
  69
  70         priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER);
  71
  72         return 0;
  73 }
  74
  75 static const struct timer_ops ast_timer_ops = {
  76         .get_count = ast_timer_get_count,
  77 };
  78
  79 static const struct udevice_id ast_timer_ids[] = {
  80         { .compatible = "aspeed,ast2500-timer" },
  81         { .compatible = "aspeed,ast2400-timer" },
  82         { }
  83 };
  84
  85 U_BOOT_DRIVER(ast_timer) = {
  86         .name = "ast_timer",
  87         .id = UCLASS_TIMER,
  88         .of_match = ast_timer_ids,
  89         .probe = ast_timer_probe,
  90         .priv_auto_alloc_size = sizeof(struct ast_timer_priv),
  91         .ofdata_to_platdata = ast_timer_ofdata_to_platdata,
  92         .ops = &ast_timer_ops,
  93         .flags = DM_FLAG_PRE_RELOC,
  94 };