u-boot/drivers/timer/omap-timer.c

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/*
* TI OMAP timer driver
*
* Copyright (C) 2015, Texas Instruments, Incorporated
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <timer.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
DECLARE_GLOBAL_DATA_PTR;
/* Timer register bits */
#define TCLR_START BIT(0) /* Start=1 */
#define TCLR_AUTO_RELOAD BIT(1) /* Auto reload */
#define TCLR_PRE_EN BIT(5) /* Pre-scaler enable */
#define TCLR_PTV_SHIFT (2) /* Pre-scaler shift value */
#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
struct omap_gptimer_regs {
unsigned int tidr; /* offset 0x00 */
unsigned char res1[12];
unsigned int tiocp_cfg; /* offset 0x10 */
unsigned char res2[12];
unsigned int tier; /* offset 0x20 */
unsigned int tistatr; /* offset 0x24 */
unsigned int tistat; /* offset 0x28 */
unsigned int tisr; /* offset 0x2c */
unsigned int tcicr; /* offset 0x30 */
unsigned int twer; /* offset 0x34 */
unsigned int tclr; /* offset 0x38 */
unsigned int tcrr; /* offset 0x3c */
unsigned int tldr; /* offset 0x40 */
unsigned int ttgr; /* offset 0x44 */
unsigned int twpc; /* offset 0x48 */
unsigned int tmar; /* offset 0x4c */
unsigned int tcar1; /* offset 0x50 */
unsigned int tscir; /* offset 0x54 */
unsigned int tcar2; /* offset 0x58 */
};
/* Omap Timer Priv */
struct omap_timer_priv {
struct omap_gptimer_regs *regs;
};
static int omap_timer_get_count(struct udevice *dev, u64 *count)
{
struct omap_timer_priv *priv = dev_get_priv(dev);
*count = readl(&priv->regs->tcrr);
return 0;
}
static int omap_timer_probe(struct udevice *dev)
{
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct omap_timer_priv *priv = dev_get_priv(dev);
uc_priv->clock_rate = TIMER_CLOCK;
/* start the counter ticking up, reload value on overflow */
writel(0, &priv->regs->tldr);
/* enable timer */
writel((CONFIG_SYS_PTV << 2) | TCLR_PRE_EN | TCLR_AUTO_RELOAD |
TCLR_START, &priv->regs->tclr);
return 0;
}
static int omap_timer_ofdata_to_platdata(struct udevice *dev)
{
struct omap_timer_priv *priv = dev_get_priv(dev);
priv->regs = (struct omap_gptimer_regs *)dev_get_addr(dev);
return 0;
}
static const struct timer_ops omap_timer_ops = {
.get_count = omap_timer_get_count,
};
static const struct udevice_id omap_timer_ids[] = {
{ .compatible = "ti,am335x-timer" },
{ .compatible = "ti,am4372-timer" },
{ .compatible = "ti,omap5430-timer" },
{}
};
U_BOOT_DRIVER(omap_timer) = {
.name = "omap_timer",
.id = UCLASS_TIMER,
.of_match = omap_timer_ids,
.ofdata_to_platdata = omap_timer_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct omap_timer_priv),
.probe = omap_timer_probe,
.ops = &omap_timer_ops,
.flags = DM_FLAG_PRE_RELOC,
};