u-boot/drivers/timer/omap-timer.c
Lokesh Vutla 84b4221cff dm: omap-timer: Update clock rate only if not populated
timer_pre_probe() tries to populate the clock rate from DT. omap
timer driver tries to overwrite this value irrespective of the value
populated fro DT. So update this value only when DT doesn't populate
the clock rate.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
2018-09-10 20:48:19 -04:00

108 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* TI OMAP timer driver
*
* Copyright (C) 2015, Texas Instruments, Incorporated
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <timer.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
/* 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 = timer_conv_64(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);
if (!uc_priv->clock_rate)
uc_priv->clock_rate = TIMER_CLOCK;
/* start the counter ticking up, reload value on overflow */
writel(0, &priv->regs->tldr);
writel(0, &priv->regs->tcrr);
/* 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 = map_physmem(devfdt_get_addr(dev),
sizeof(struct omap_gptimer_regs), MAP_NOCACHE);
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,
};