u-boot/drivers/pwm/exynos_pwm.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

117 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2016 Google Inc.
*/
#include <common.h>
#include <dm.h>
#include <pwm.h>
#include <asm/io.h>
#include <asm/arch/clk.h>
#include <asm/arch/clock.h>
#include <asm/arch/pwm.h>
struct exynos_pwm_priv {
struct s5p_timer *regs;
};
static int exynos_pwm_set_config(struct udevice *dev, uint channel,
uint period_ns, uint duty_ns)
{
struct exynos_pwm_priv *priv = dev_get_priv(dev);
struct s5p_timer *regs = priv->regs;
unsigned int offset, prescaler;
uint div = 4, rate, rate_ns;
u32 val;
u32 tcnt, tcmp, tcon;
if (channel >= 5)
return -EINVAL;
debug("%s: Configure '%s' channel %u, period_ns %u, duty_ns %u\n",
__func__, dev->name, channel, period_ns, duty_ns);
val = readl(&regs->tcfg0);
prescaler = (channel < 2 ? val : (val >> 8)) & 0xff;
div = (readl(&regs->tcfg1) >> MUX_DIV_SHIFT(channel)) & 0xf;
rate = get_pwm_clk() / ((prescaler + 1) * (1 << div));
debug("%s: pwm_clk %lu, rate %u\n", __func__, get_pwm_clk(), rate);
if (channel < 4) {
rate_ns = 1000000000 / rate;
tcnt = period_ns / rate_ns;
tcmp = duty_ns / rate_ns;
debug("%s: tcnt %u, tcmp %u\n", __func__, tcnt, tcmp);
offset = channel * 3;
writel(tcnt, &regs->tcntb0 + offset);
writel(tcmp, &regs->tcmpb0 + offset);
}
tcon = readl(&regs->tcon);
tcon |= TCON_UPDATE(channel);
if (channel < 4)
tcon |= TCON_AUTO_RELOAD(channel);
else
tcon |= TCON4_AUTO_RELOAD;
writel(tcon, &regs->tcon);
tcon &= ~TCON_UPDATE(channel);
writel(tcon, &regs->tcon);
return 0;
}
static int exynos_pwm_set_enable(struct udevice *dev, uint channel,
bool enable)
{
struct exynos_pwm_priv *priv = dev_get_priv(dev);
struct s5p_timer *regs = priv->regs;
u32 mask;
if (channel >= 4)
return -EINVAL;
debug("%s: Enable '%s' channel %u\n", __func__, dev->name, channel);
mask = TCON_START(channel);
clrsetbits_le32(&regs->tcon, mask, enable ? mask : 0);
return 0;
}
static int exynos_pwm_probe(struct udevice *dev)
{
struct exynos_pwm_priv *priv = dev_get_priv(dev);
struct s5p_timer *regs = priv->regs;
writel(PRESCALER_0 | PRESCALER_1 << 8, &regs->tcfg0);
return 0;
}
static int exynos_pwm_ofdata_to_platdata(struct udevice *dev)
{
struct exynos_pwm_priv *priv = dev_get_priv(dev);
priv->regs = (struct s5p_timer *)devfdt_get_addr(dev);
return 0;
}
static const struct pwm_ops exynos_pwm_ops = {
.set_config = exynos_pwm_set_config,
.set_enable = exynos_pwm_set_enable,
};
static const struct udevice_id exynos_channels[] = {
{ .compatible = "samsung,exynos4210-pwm" },
{ }
};
U_BOOT_DRIVER(exynos_pwm) = {
.name = "exynos_pwm",
.id = UCLASS_PWM,
.of_match = exynos_channels,
.ops = &exynos_pwm_ops,
.probe = exynos_pwm_probe,
.ofdata_to_platdata = exynos_pwm_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct exynos_pwm_priv),
};