sunxi_pwm.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2017-2018 Vasily Khoruzhick <anarsoul@gmail.com>
*/
#include <common.h>
#include <div64.h>
#include <dm.h>
#include <pwm.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/io.h>
#include <asm/arch/pwm.h>
#include <asm/arch/gpio.h>
#include <power/regulator.h>
DECLARE_GLOBAL_DATA_PTR;
#define OSC_24MHZ 24000000
struct sunxi_pwm_priv {
struct sunxi_pwm *regs;
bool invert;
u32 prescaler;
};
static const u32 prescaler_table[] = {
120, /* 0000 */
180, /* 0001 */
240, /* 0010 */
360, /* 0011 */
480, /* 0100 */
0, /* 0101 */
0, /* 0110 */
0, /* 0111 */
12000, /* 1000 */
24000, /* 1001 */
36000, /* 1010 */
48000, /* 1011 */
72000, /* 1100 */
0, /* 1101 */
0, /* 1110 */
1, /* 1111 */
};
static int sunxi_pwm_config_pinmux(void)
{
#ifdef CONFIG_MACH_SUN50I
sunxi_gpio_set_cfgpin(SUNXI_GPD(22), SUNXI_GPD_PWM);
#endif
return 0;
}
static int sunxi_pwm_set_invert(struct udevice *dev, uint channel,
bool polarity)
{
struct sunxi_pwm_priv *priv = dev_get_priv(dev);
debug("%s: polarity=%u\n", __func__, polarity);
priv->invert = polarity;
return 0;
}
static int sunxi_pwm_set_config(struct udevice *dev, uint channel,
uint period_ns, uint duty_ns)
{
struct sunxi_pwm_priv *priv = dev_get_priv(dev);
struct sunxi_pwm *regs = priv->regs;
int best_prescaler = 0;
u32 v, best_period = 0, duty;
u64 best_scaled_freq = 0;
const u32 nsecs_per_sec = 1000000000U;
debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns);
for (int prescaler = 0; prescaler <= SUNXI_PWM_CTRL_PRESCALE0_MASK;
prescaler++) {
u32 period = 0;
u64 scaled_freq = 0;
if (!prescaler_table[prescaler])
continue;
scaled_freq = lldiv(OSC_24MHZ, prescaler_table[prescaler]);
period = lldiv(scaled_freq * period_ns, nsecs_per_sec);
if ((period - 1 <= SUNXI_PWM_CH0_PERIOD_MAX) &&
best_period < period) {
best_period = period;
best_scaled_freq = scaled_freq;
best_prescaler = prescaler;
}
}
if (best_period - 1 > SUNXI_PWM_CH0_PERIOD_MAX) {
debug("%s: failed to find prescaler value\n", __func__);
return -EINVAL;
}
duty = lldiv(best_scaled_freq * duty_ns, nsecs_per_sec);
if (priv->prescaler != best_prescaler) {
/* Mask clock to update prescaler */
v = readl(®s->ctrl);
v &= ~SUNXI_PWM_CTRL_CLK_GATE;
writel(v, ®s->ctrl);
v &= ~SUNXI_PWM_CTRL_PRESCALE0_MASK;
v |= (best_prescaler & SUNXI_PWM_CTRL_PRESCALE0_MASK);
writel(v, ®s->ctrl);
v |= SUNXI_PWM_CTRL_CLK_GATE;
writel(v, ®s->ctrl);
priv->prescaler = best_prescaler;
}
writel(SUNXI_PWM_CH0_PERIOD_PRD(best_period) |
SUNXI_PWM_CH0_PERIOD_DUTY(duty), ®s->ch0_period);
debug("%s: prescaler: %d, period: %d, duty: %d\n",
__func__, priv->prescaler,
best_period, duty);
return 0;
}
static int sunxi_pwm_set_enable(struct udevice *dev, uint channel, bool enable)
{
struct sunxi_pwm_priv *priv = dev_get_priv(dev);
struct sunxi_pwm *regs = priv->regs;
u32 v;
debug("%s: Enable '%s'\n", __func__, dev->name);
v = readl(®s->ctrl);
if (!enable) {
v &= ~SUNXI_PWM_CTRL_ENABLE0;
writel(v, ®s->ctrl);
return 0;
}
sunxi_pwm_config_pinmux();
if (priv->invert)
v &= ~SUNXI_PWM_CTRL_CH0_ACT_STA;
else
v |= SUNXI_PWM_CTRL_CH0_ACT_STA;
v |= SUNXI_PWM_CTRL_ENABLE0;
writel(v, ®s->ctrl);
return 0;
}
static int sunxi_pwm_ofdata_to_platdata(struct udevice *dev)
{
struct sunxi_pwm_priv *priv = dev_get_priv(dev);
priv->regs = (struct sunxi_pwm *)devfdt_get_addr(dev);
return 0;
}
static int sunxi_pwm_probe(struct udevice *dev)
{
return 0;
}
static const struct pwm_ops sunxi_pwm_ops = {
.set_invert = sunxi_pwm_set_invert,
.set_config = sunxi_pwm_set_config,
.set_enable = sunxi_pwm_set_enable,
};
static const struct udevice_id sunxi_pwm_ids[] = {
{ .compatible = "allwinner,sun5i-a13-pwm" },
{ .compatible = "allwinner,sun50i-a64-pwm" },
{ }
};
U_BOOT_DRIVER(sunxi_pwm) = {
.name = "sunxi_pwm",
.id = UCLASS_PWM,
.of_match = sunxi_pwm_ids,
.ops = &sunxi_pwm_ops,
.ofdata_to_platdata = sunxi_pwm_ofdata_to_platdata,
.probe = sunxi_pwm_probe,
.priv_auto_alloc_size = sizeof(struct sunxi_pwm_priv),
};