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
  15 /* Timer register bits */
  16 #define TCLR_START                      BIT(0)  /* Start=1 */
  17 #define TCLR_AUTO_RELOAD                BIT(1)  /* Auto reload */
  18 #define TCLR_PRE_EN                     BIT(5)  /* Pre-scaler enable */
  19 #define TCLR_PTV_SHIFT                  (2)     /* Pre-scaler shift value */
  20
  21 #define TIMER_CLOCK             (V_SCLK / (2 << CONFIG_SYS_PTV))
  22
  23 struct omap_gptimer_regs {
  24         unsigned int tidr;              /* offset 0x00 */
  25         unsigned char res1[12];
  26         unsigned int tiocp_cfg;         /* offset 0x10 */
  27         unsigned char res2[12];
  28         unsigned int tier;              /* offset 0x20 */
  29         unsigned int tistatr;           /* offset 0x24 */
  30         unsigned int tistat;            /* offset 0x28 */
  31         unsigned int tisr;              /* offset 0x2c */
  32         unsigned int tcicr;             /* offset 0x30 */
  33         unsigned int twer;              /* offset 0x34 */
  34         unsigned int tclr;              /* offset 0x38 */
  35         unsigned int tcrr;              /* offset 0x3c */
  36         unsigned int tldr;              /* offset 0x40 */
  37         unsigned int ttgr;              /* offset 0x44 */
  38         unsigned int twpc;              /* offset 0x48 */
  39         unsigned int tmar;              /* offset 0x4c */
  40         unsigned int tcar1;             /* offset 0x50 */
  41         unsigned int tscir;             /* offset 0x54 */
  42         unsigned int tcar2;             /* offset 0x58 */
  43 };
  44
  45 /* Omap Timer Priv */
  46 struct omap_timer_priv {
  47         struct omap_gptimer_regs *regs;
  48 };
  49
  50 static int omap_timer_get_count(struct udevice *dev, u64 *count)
  51 {
  52         struct omap_timer_priv *priv = dev_get_priv(dev);
  53
  54         *count = timer_conv_64(readl(&priv->regs->tcrr));
  55
  56         return 0;
  57 }
  58
  59 static int omap_timer_probe(struct udevice *dev)
  60 {
  61         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  62         struct omap_timer_priv *priv = dev_get_priv(dev);
  63
  64         if (!uc_priv->clock_rate)
  65                 uc_priv->clock_rate = TIMER_CLOCK;
  66
  67         /* start the counter ticking up, reload value on overflow */
  68         writel(0, &priv->regs->tldr);
  69         writel(0, &priv->regs->tcrr);
  70         /* enable timer */
  71         writel((CONFIG_SYS_PTV << 2) | TCLR_PRE_EN | TCLR_AUTO_RELOAD |
  72                TCLR_START, &priv->regs->tclr);
  73
  74         return 0;
  75 }
  76
  77 static int omap_timer_ofdata_to_platdata(struct udevice *dev)
  78 {
  79         struct omap_timer_priv *priv = dev_get_priv(dev);
  80
  81         priv->regs = map_physmem(devfdt_get_addr(dev),
  82                                  sizeof(struct omap_gptimer_regs), MAP_NOCACHE);
  83
  84         return 0;
  85 }
  86
  87
  88 static const struct timer_ops omap_timer_ops = {
  89         .get_count = omap_timer_get_count,
  90 };
  91
  92 static const struct udevice_id omap_timer_ids[] = {
  93         { .compatible = "ti,am335x-timer" },
  94         { .compatible = "ti,am4372-timer" },
  95         { .compatible = "ti,omap5430-timer" },
  96         {}
  97 };
  98
  99 U_BOOT_DRIVER(omap_timer) = {
 100         .name   = "omap_timer",
 101         .id     = UCLASS_TIMER,
 102         .of_match = omap_timer_ids,
 103         .ofdata_to_platdata = omap_timer_ofdata_to_platdata,
 104         .priv_auto_alloc_size = sizeof(struct omap_timer_priv),
 105         .probe = omap_timer_probe,
 106         .ops    = &omap_timer_ops,
 107         .flags = DM_FLAG_PRE_RELOC,
 108 };