u-boot/drivers/pwm/pwm-cadence-ttc.c

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// SPDX-License-Identifier: GPL-2.0
/*
* (C) Copyright 2021 Xilinx, Inc. Michal Simek
*/
#define LOG_CATEGORY UCLASS_PWM
#include <clk.h>
#include <common.h>
#include <div64.h>
#include <dm.h>
#include <log.h>
#include <pwm.h>
#include <asm/io.h>
#include <log.h>
#include <div64.h>
#include <linux/bitfield.h>
#include <linux/math64.h>
#include <linux/log2.h>
#include <dm/device_compat.h>
#define CLOCK_CONTROL 0
#define COUNTER_CONTROL 0xc
#define INTERVAL_COUNTER 0x24
#define MATCH_1_COUNTER 0x30
#define CLK_FALLING_EDGE BIT(6)
#define CLK_SRC_EXTERNAL BIT(5)
#define CLK_PRESCALE_MASK GENMASK(4, 1)
#define CLK_PRESCALE_ENABLE BIT(0)
#define COUNTER_WAVE_POL BIT(6)
#define COUNTER_WAVE_DISABLE BIT(5)
#define COUNTER_RESET BIT(4)
#define COUNTER_MATCH_ENABLE BIT(3)
#define COUNTER_DECREMENT_ENABLE BIT(2)
#define COUNTER_INTERVAL_ENABLE BIT(1)
#define COUNTER_COUNTING_DISABLE BIT(0)
#define NSEC_PER_SEC 1000000000L
#define TTC_REG(reg, channel) ((reg) + (channel) * sizeof(u32))
#define TTC_CLOCK_CONTROL(reg, channel) \
TTC_REG((reg) + CLOCK_CONTROL, (channel))
#define TTC_COUNTER_CONTROL(reg, channel) \
TTC_REG((reg) + COUNTER_CONTROL, (channel))
#define TTC_INTERVAL_COUNTER(reg, channel) \
TTC_REG((reg) + INTERVAL_COUNTER, (channel))
#define TTC_MATCH_1_COUNTER(reg, channel) \
TTC_REG((reg) + MATCH_1_COUNTER, (channel))
struct cadence_ttc_pwm_plat {
u8 *regs;
u32 timer_width;
};
struct cadence_ttc_pwm_priv {
u8 *regs;
u32 timer_width;
u32 timer_mask;
unsigned long frequency;
bool invert[2];
};
static int cadence_ttc_pwm_set_invert(struct udevice *dev, uint channel,
bool polarity)
{
struct cadence_ttc_pwm_priv *priv = dev_get_priv(dev);
if (channel > 2) {
dev_err(dev, "Unsupported channel number %d(max 2)\n", channel);
return -EINVAL;
}
priv->invert[channel] = polarity;
dev_dbg(dev, "polarity=%u. Please config PWM again\n", polarity);
return 0;
}
static int cadence_ttc_pwm_set_config(struct udevice *dev, uint channel,
uint period_ns, uint duty_ns)
{
struct cadence_ttc_pwm_priv *priv = dev_get_priv(dev);
u32 counter_ctrl, clock_ctrl;
int period_clocks, duty_clocks, prescaler;
dev_dbg(dev, "channel %d, duty %d/period %d ns\n", channel,
duty_ns, period_ns);
if (channel > 2) {
dev_err(dev, "Unsupported channel number %d(max 2)\n", channel);
return -EINVAL;
}
/* Make sure counter is stopped */
counter_ctrl = readl(TTC_COUNTER_CONTROL(priv->regs, channel));
setbits_le32(TTC_COUNTER_CONTROL(priv->regs, channel),
COUNTER_COUNTING_DISABLE | COUNTER_WAVE_DISABLE);
/* Calculate period, prescaler and set clock control register */
period_clocks = div64_u64(((int64_t)period_ns * priv->frequency),
NSEC_PER_SEC);
prescaler = ilog2(period_clocks) + 1 - priv->timer_width;
if (prescaler < 0)
prescaler = 0;
clock_ctrl = readl(TTC_CLOCK_CONTROL(priv->regs, channel));
if (!prescaler) {
clock_ctrl &= ~(CLK_PRESCALE_ENABLE | CLK_PRESCALE_MASK);
} else {
clock_ctrl &= ~CLK_PRESCALE_MASK;
clock_ctrl |= CLK_PRESCALE_ENABLE;
clock_ctrl |= FIELD_PREP(CLK_PRESCALE_MASK, prescaler - 1);
};
/* External source is not handled by this driver now */
clock_ctrl &= ~CLK_SRC_EXTERNAL;
writel(clock_ctrl, TTC_CLOCK_CONTROL(priv->regs, channel));
/* Calculate interval and set counter control value */
duty_clocks = div64_u64(((int64_t)duty_ns * priv->frequency),
NSEC_PER_SEC);
writel((period_clocks >> prescaler) & priv->timer_mask,
TTC_INTERVAL_COUNTER(priv->regs, channel));
writel((duty_clocks >> prescaler) & priv->timer_mask,
TTC_MATCH_1_COUNTER(priv->regs, channel));
/* Restore/reset counter */
counter_ctrl &= ~COUNTER_DECREMENT_ENABLE;
counter_ctrl |= COUNTER_INTERVAL_ENABLE |
COUNTER_RESET |
COUNTER_MATCH_ENABLE;
if (priv->invert[channel])
counter_ctrl |= COUNTER_WAVE_POL;
else
counter_ctrl &= ~COUNTER_WAVE_POL;
writel(counter_ctrl, TTC_COUNTER_CONTROL(priv->regs, channel));
dev_dbg(dev, "%d/%d clocks, prescaler 2^%d\n", duty_clocks,
period_clocks, prescaler);
return 0;
};
static int cadence_ttc_pwm_set_enable(struct udevice *dev, uint channel,
bool enable)
{
struct cadence_ttc_pwm_priv *priv = dev_get_priv(dev);
if (channel > 2) {
dev_err(dev, "Unsupported channel number %d(max 2)\n", channel);
return -EINVAL;
}
dev_dbg(dev, "Enable: %d, channel %d\n", enable, channel);
if (enable) {
clrbits_le32(TTC_COUNTER_CONTROL(priv->regs, channel),
COUNTER_COUNTING_DISABLE |
COUNTER_WAVE_DISABLE);
setbits_le32(TTC_COUNTER_CONTROL(priv->regs, channel),
COUNTER_RESET);
} else {
setbits_le32(TTC_COUNTER_CONTROL(priv->regs, channel),
COUNTER_COUNTING_DISABLE |
COUNTER_WAVE_DISABLE);
}
return 0;
};
static int cadence_ttc_pwm_probe(struct udevice *dev)
{
struct cadence_ttc_pwm_priv *priv = dev_get_priv(dev);
struct cadence_ttc_pwm_plat *plat = dev_get_plat(dev);
struct clk clk;
int ret;
priv->regs = plat->regs;
priv->timer_width = plat->timer_width;
priv->timer_mask = GENMASK(priv->timer_width - 1, 0);
ret = clk_get_by_index(dev, 0, &clk);
if (ret < 0) {
dev_err(dev, "failed to get clock\n");
return ret;
}
priv->frequency = clk_get_rate(&clk);
if (IS_ERR_VALUE(priv->frequency)) {
dev_err(dev, "failed to get rate\n");
return priv->frequency;
}
dev_dbg(dev, "Clk frequency: %ld\n", priv->frequency);
ret = clk_enable(&clk);
if (ret) {
dev_err(dev, "failed to enable clock\n");
return ret;
}
return 0;
}
static int cadence_ttc_pwm_of_to_plat(struct udevice *dev)
{
struct cadence_ttc_pwm_plat *plat = dev_get_plat(dev);
const char *cells;
cells = dev_read_prop(dev, "#pwm-cells", NULL);
if (!cells)
return -EINVAL;
plat->regs = dev_read_addr_ptr(dev);
plat->timer_width = dev_read_u32_default(dev, "timer-width", 16);
return 0;
}
static int cadence_ttc_pwm_bind(struct udevice *dev)
{
const char *cells;
cells = dev_read_prop(dev, "#pwm-cells", NULL);
if (!cells)
return -ENODEV;
return 0;
}
static const struct pwm_ops cadence_ttc_pwm_ops = {
.set_invert = cadence_ttc_pwm_set_invert,
.set_config = cadence_ttc_pwm_set_config,
.set_enable = cadence_ttc_pwm_set_enable,
};
static const struct udevice_id cadence_ttc_pwm_ids[] = {
{ .compatible = "cdns,ttc" },
{ }
};
U_BOOT_DRIVER(cadence_ttc_pwm) = {
.name = "cadence_ttc_pwm",
.id = UCLASS_PWM,
.of_match = cadence_ttc_pwm_ids,
.ops = &cadence_ttc_pwm_ops,
.bind = cadence_ttc_pwm_bind,
.of_to_plat = cadence_ttc_pwm_of_to_plat,
.probe = cadence_ttc_pwm_probe,
.priv_auto = sizeof(struct cadence_ttc_pwm_priv),
.plat_auto = sizeof(struct cadence_ttc_pwm_plat),
};