u-boot/drivers/pwm/pwm-mtk.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
*
* Author: Sam Shih <sam.shih@mediatek.com>
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <pwm.h>
#include <div64.h>
#include <linux/bitops.h>
#include <linux/io.h>
/* PWM registers and bits definitions */
#define PWMCON 0x00
#define PWMHDUR 0x04
#define PWMLDUR 0x08
#define PWMGDUR 0x0c
#define PWMWAVENUM 0x28
#define PWMDWIDTH 0x2c
#define PWM45DWIDTH_FIXUP 0x30
#define PWMTHRES 0x30
#define PWM45THRES_FIXUP 0x34
#define PWM_CLK_DIV_MAX 7
#define MAX_PWM_NUM 8
#define NSEC_PER_SEC 1000000000L
static const unsigned int mtk_pwm_reg_offset[] = {
0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
};
struct mtk_pwm_soc {
unsigned int num_pwms;
bool pwm45_fixup;
};
struct mtk_pwm_priv {
void __iomem *base;
struct clk top_clk;
struct clk main_clk;
struct clk pwm_clks[MAX_PWM_NUM];
const struct mtk_pwm_soc *soc;
};
static void mtk_pwm_w32(struct udevice *dev, uint channel, uint reg, uint val)
{
struct mtk_pwm_priv *priv = dev_get_priv(dev);
u32 offset = mtk_pwm_reg_offset[channel];
writel(val, priv->base + offset + reg);
}
static int mtk_pwm_set_config(struct udevice *dev, uint channel,
uint period_ns, uint duty_ns)
{
struct mtk_pwm_priv *priv = dev_get_priv(dev);
u32 clkdiv = 0, clksel = 0, cnt_period, cnt_duty,
reg_width = PWMDWIDTH, reg_thres = PWMTHRES;
u64 resolution;
int ret = 0;
clk_enable(&priv->top_clk);
clk_enable(&priv->main_clk);
/* Using resolution in picosecond gets accuracy higher */
resolution = (u64)NSEC_PER_SEC * 1000;
do_div(resolution, clk_get_rate(&priv->pwm_clks[channel]));
cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
while (cnt_period > 8191) {
resolution *= 2;
clkdiv++;
cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
resolution);
if (clkdiv > PWM_CLK_DIV_MAX && clksel == 0) {
clksel = 1;
clkdiv = 0;
resolution = (u64)NSEC_PER_SEC * 1000 * 1625;
do_div(resolution,
clk_get_rate(&priv->pwm_clks[channel]));
cnt_period = DIV_ROUND_CLOSEST_ULL(
(u64)period_ns * 1000, resolution);
clk_enable(&priv->pwm_clks[channel]);
}
}
if (clkdiv > PWM_CLK_DIV_MAX && clksel == 1) {
printf("pwm period %u not supported\n", period_ns);
return -EINVAL;
}
if (priv->soc->pwm45_fixup && channel > 2) {
/*
* PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
* from the other PWMs on MT7623.
*/
reg_width = PWM45DWIDTH_FIXUP;
reg_thres = PWM45THRES_FIXUP;
}
cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
if (clksel == 1)
mtk_pwm_w32(dev, channel, PWMCON, BIT(15) | BIT(3) | clkdiv);
else
mtk_pwm_w32(dev, channel, PWMCON, BIT(15) | clkdiv);
mtk_pwm_w32(dev, channel, reg_width, cnt_period);
mtk_pwm_w32(dev, channel, reg_thres, cnt_duty);
return ret;
};
static int mtk_pwm_set_enable(struct udevice *dev, uint channel, bool enable)
{
struct mtk_pwm_priv *priv = dev_get_priv(dev);
u32 val = 0;
val = readl(priv->base);
if (enable)
val |= BIT(channel);
else
val &= ~BIT(channel);
writel(val, priv->base);
return 0;
};
static int mtk_pwm_probe(struct udevice *dev)
{
struct mtk_pwm_priv *priv = dev_get_priv(dev);
int ret = 0;
int i;
priv->soc = (struct mtk_pwm_soc *)dev_get_driver_data(dev);
priv->base = dev_read_addr_ptr(dev);
if (!priv->base)
return -EINVAL;
ret = clk_get_by_name(dev, "top", &priv->top_clk);
if (ret < 0)
return ret;
ret = clk_get_by_name(dev, "main", &priv->main_clk);
if (ret < 0)
return ret;
for (i = 0; i < priv->soc->num_pwms; i++) {
char name[8];
snprintf(name, sizeof(name), "pwm%d", i + 1);
ret = clk_get_by_name(dev, name, &priv->pwm_clks[i]);
if (ret < 0)
return ret;
}
return ret;
}
static const struct pwm_ops mtk_pwm_ops = {
.set_config = mtk_pwm_set_config,
.set_enable = mtk_pwm_set_enable,
};
static const struct mtk_pwm_soc mt7622_data = {
.num_pwms = 6,
.pwm45_fixup = false,
};
static const struct mtk_pwm_soc mt7623_data = {
.num_pwms = 5,
.pwm45_fixup = true,
};
static const struct mtk_pwm_soc mt7629_data = {
.num_pwms = 1,
.pwm45_fixup = false,
};
static const struct udevice_id mtk_pwm_ids[] = {
{ .compatible = "mediatek,mt7622-pwm", .data = (ulong)&mt7622_data },
{ .compatible = "mediatek,mt7623-pwm", .data = (ulong)&mt7623_data },
{ .compatible = "mediatek,mt7629-pwm", .data = (ulong)&mt7629_data },
{ }
};
U_BOOT_DRIVER(mtk_pwm) = {
.name = "mtk_pwm",
.id = UCLASS_PWM,
.of_match = mtk_pwm_ids,
.ops = &mtk_pwm_ops,
.probe = mtk_pwm_probe,
.priv_auto_alloc_size = sizeof(struct mtk_pwm_priv),
};