drivers/timer/omap-timer.c

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