u-boot-brain/drivers/timer/stm32_timer.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

138 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018, STMicroelectronics - All Rights Reserved
* Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <fdtdec.h>
#include <timer.h>
#include <asm/io.h>
/* Timer control1 register */
#define CR1_CEN BIT(0)
#define CR1_ARPE BIT(7)
/* Event Generation Register register */
#define EGR_UG BIT(0)
/* Auto reload register for free running config */
#define GPT_FREE_RUNNING 0xFFFFFFFF
struct stm32_timer_regs {
u32 cr1;
u32 cr2;
u32 smcr;
u32 dier;
u32 sr;
u32 egr;
u32 ccmr1;
u32 ccmr2;
u32 ccer;
u32 cnt;
u32 psc;
u32 arr;
u32 reserved;
u32 ccr1;
u32 ccr2;
u32 ccr3;
u32 ccr4;
u32 reserved1;
u32 dcr;
u32 dmar;
u32 tim2_5_or;
};
struct stm32_timer_priv {
struct stm32_timer_regs *base;
};
static int stm32_timer_get_count(struct udevice *dev, u64 *count)
{
struct stm32_timer_priv *priv = dev_get_priv(dev);
struct stm32_timer_regs *regs = priv->base;
*count = readl(&regs->cnt);
return 0;
}
static int stm32_timer_probe(struct udevice *dev)
{
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct stm32_timer_priv *priv = dev_get_priv(dev);
struct stm32_timer_regs *regs;
struct clk clk;
fdt_addr_t addr;
int ret;
u32 rate, psc;
addr = dev_read_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
priv->base = (struct stm32_timer_regs *)addr;
ret = clk_get_by_index(dev, 0, &clk);
if (ret < 0)
return ret;
ret = clk_enable(&clk);
if (ret) {
dev_err(dev, "failed to enable clock\n");
return ret;
}
regs = priv->base;
/* Stop the timer */
clrbits_le32(&regs->cr1, CR1_CEN);
/* get timer clock */
rate = clk_get_rate(&clk);
/* we set timer prescaler to obtain a 1MHz timer counter frequency */
psc = (rate / CONFIG_SYS_HZ_CLOCK) - 1;
writel(psc, &regs->psc);
/* Set timer frequency to 1MHz */
uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
/* Configure timer for auto-reload */
setbits_le32(&regs->cr1, CR1_ARPE);
/* load value for auto reload */
writel(GPT_FREE_RUNNING, &regs->arr);
/* start timer */
setbits_le32(&regs->cr1, CR1_CEN);
/* Update generation */
setbits_le32(&regs->egr, EGR_UG);
return 0;
}
static const struct timer_ops stm32_timer_ops = {
.get_count = stm32_timer_get_count,
};
static const struct udevice_id stm32_timer_ids[] = {
{ .compatible = "st,stm32-timer" },
{}
};
U_BOOT_DRIVER(stm32_timer) = {
.name = "stm32_timer",
.id = UCLASS_TIMER,
.of_match = stm32_timer_ids,
.priv_auto_alloc_size = sizeof(struct stm32_timer_priv),
.probe = stm32_timer_probe,
.ops = &stm32_timer_ops,
.flags = DM_FLAG_PRE_RELOC,
};