u-boot/drivers/timer/atmel_pit_timer.c
Wenyou.Yang@microchip.com 47edaea494 driver: timer: Add the Atmel PIT timer driver
Add the new Atmel PIT timer driver, which supports the driver model
and device tree.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
2017-08-26 14:56:08 -04:00

90 lines
1.9 KiB
C

/*
* Copyright (C) 2017 Microchip Corporation
* Wenyou.Yang <wenyou.yang@microchip.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <timer.h>
#include <asm/io.h>
#define AT91_PIT_VALUE 0xfffff
#define AT91_PIT_PITEN BIT(24) /* Timer Enabled */
struct atmel_pit_regs {
u32 mode;
u32 status;
u32 value;
u32 value_image;
};
struct atmel_pit_platdata {
struct atmel_pit_regs *regs;
};
static int atmel_pit_get_count(struct udevice *dev, u64 *count)
{
struct atmel_pit_platdata *plat = dev_get_platdata(dev);
struct atmel_pit_regs *const regs = plat->regs;
u32 val = readl(&regs->value_image);
*count = timer_conv_64(val);
return 0;
}
static int atmel_pit_probe(struct udevice *dev)
{
struct atmel_pit_platdata *plat = dev_get_platdata(dev);
struct atmel_pit_regs *const regs = plat->regs;
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct clk clk;
ulong clk_rate;
int ret;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return -EINVAL;
clk_rate = clk_get_rate(&clk);
if (!clk_rate)
return -EINVAL;
uc_priv->clock_rate = clk_rate / 16;
writel(AT91_PIT_VALUE | AT91_PIT_PITEN, &regs->mode);
return 0;
}
static int atmel_pit_ofdata_to_platdata(struct udevice *dev)
{
struct atmel_pit_platdata *plat = dev_get_platdata(dev);
plat->regs = (struct atmel_pit_regs *)devfdt_get_addr_ptr(dev);
return 0;
}
static const struct timer_ops atmel_pit_ops = {
.get_count = atmel_pit_get_count,
};
static const struct udevice_id atmel_pit_ids[] = {
{ .compatible = "atmel,at91sam9260-pit" },
{ }
};
U_BOOT_DRIVER(atmel_pit) = {
.name = "atmel_pit",
.id = UCLASS_TIMER,
.of_match = atmel_pit_ids,
.ofdata_to_platdata = atmel_pit_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct atmel_pit_platdata),
.probe = atmel_pit_probe,
.ops = &atmel_pit_ops,
.flags = DM_FLAG_PRE_RELOC,
};