drivers/timer/omap-timer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * TI OMAP timer driver
   4  *
   5  * Copyright (C) 2015, Texas Instruments, Incorporated
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <errno.h>
  11 #include <timer.h>
  12 #include <asm/io.h>
  13 #include <asm/arch/clock.h>
  14 #include <linux/bitops.h>
  15
  16 /* Timer register bits */
  17 #define TCLR_START                      BIT(0)  /* Start=1 */
  18 #define TCLR_AUTO_RELOAD                BIT(1)  /* Auto reload */
  19 #define TCLR_PRE_EN                     BIT(5)  /* Pre-scaler enable */
  20 #define TCLR_PTV_SHIFT                  (2)     /* Pre-scaler shift value */
  21
  22 struct omap_gptimer_regs {
  23         unsigned int tidr;              /* offset 0x00 */
  24         unsigned char res1[12];
  25         unsigned int tiocp_cfg;         /* offset 0x10 */
  26         unsigned char res2[12];
  27         unsigned int tier;              /* offset 0x20 */
  28         unsigned int tistatr;           /* offset 0x24 */
  29         unsigned int tistat;            /* offset 0x28 */
  30         unsigned int tisr;              /* offset 0x2c */
  31         unsigned int tcicr;             /* offset 0x30 */
  32         unsigned int twer;              /* offset 0x34 */
  33         unsigned int tclr;              /* offset 0x38 */
  34         unsigned int tcrr;              /* offset 0x3c */
  35         unsigned int tldr;              /* offset 0x40 */
  36         unsigned int ttgr;              /* offset 0x44 */
  37         unsigned int twpc;              /* offset 0x48 */
  38         unsigned int tmar;              /* offset 0x4c */
  39         unsigned int tcar1;             /* offset 0x50 */
  40         unsigned int tscir;             /* offset 0x54 */
  41         unsigned int tcar2;             /* offset 0x58 */
  42 };
  43
  44 /* Omap Timer Priv */
  45 struct omap_timer_priv {
  46         struct omap_gptimer_regs *regs;
  47 };
  48
  49 static u64 omap_timer_get_count(struct udevice *dev)
  50 {
  51         struct omap_timer_priv *priv = dev_get_priv(dev);
  52
  53         return timer_conv_64(readl(&priv->regs->tcrr));
  54 }
  55
  56 static int omap_timer_probe(struct udevice *dev)
  57 {
  58         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  59         struct omap_timer_priv *priv = dev_get_priv(dev);
  60
  61         if (!uc_priv->clock_rate)
  62                 uc_priv->clock_rate = V_SCLK;
  63
  64         uc_priv->clock_rate /= (2 << CONFIG_SYS_PTV);
  65
  66         /* start the counter ticking up, reload value on overflow */
  67         writel(0, &priv->regs->tldr);
  68         writel(0, &priv->regs->tcrr);
  69         /* enable timer */
  70         writel((CONFIG_SYS_PTV << 2) | TCLR_PRE_EN | TCLR_AUTO_RELOAD |
  71                TCLR_START, &priv->regs->tclr);
  72
  73         return 0;
  74 }
  75
  76 static int omap_timer_of_to_plat(struct udevice *dev)
  77 {
  78         struct omap_timer_priv *priv = dev_get_priv(dev);
  79
  80         priv->regs = map_physmem(dev_read_addr(dev),
  81                                  sizeof(struct omap_gptimer_regs), MAP_NOCACHE);
  82
  83         return 0;
  84 }
  85
  86 #if CONFIG_IS_ENABLED(BOOTSTAGE)
  87 ulong timer_get_boot_us(void)
  88 {
  89         u64 ticks = 0;
  90         u32 rate = 1;
  91         u64 us;
  92         int ret;
  93
  94         ret = dm_timer_init();
  95         if (!ret) {
  96                 /* The timer is available */
  97                 rate = timer_get_rate(gd->timer);
  98                 timer_get_count(gd->timer, &ticks);
  99         } else {
 100                 return 0;
 101         }
 102
 103         us = (ticks * 1000) / rate;
 104         return us;
 105 }
 106 #endif
 107
 108 static const struct timer_ops omap_timer_ops = {
 109         .get_count = omap_timer_get_count,
 110 };
 111
 112 static const struct udevice_id omap_timer_ids[] = {
 113         { .compatible = "ti,am335x-timer" },
 114         { .compatible = "ti,am4372-timer" },
 115         { .compatible = "ti,omap5430-timer" },
 116         {}
 117 };
 118
 119 U_BOOT_DRIVER(omap_timer) = {
 120         .name   = "omap_timer",
 121         .id     = UCLASS_TIMER,
 122         .of_match = omap_timer_ids,
 123         .of_to_plat = omap_timer_of_to_plat,
 124         .priv_auto      = sizeof(struct omap_timer_priv),
 125         .probe = omap_timer_probe,
 126         .ops    = &omap_timer_ops,
 127 };