linux/drivers/pwm/pwm-mediatek.c
Thierry Reding 80943bbdcf pwm: Stop referencing pwm->chip
Drivers have access to the chip via a function argument already, so
there is no need to reference it via the PWM device.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-12-20 16:04:14 +01:00

391 lines
9.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* MediaTek Pulse Width Modulator driver
*
* Copyright (C) 2015 John Crispin <blogic@openwrt.org>
* Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com>
*
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/slab.h>
#include <linux/types.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_CK_26M_SEL 0x210
#define PWM_CLK_DIV_MAX 7
struct pwm_mediatek_of_data {
unsigned int num_pwms;
bool pwm45_fixup;
bool has_ck_26m_sel;
const unsigned int *reg_offset;
};
/**
* struct pwm_mediatek_chip - struct representing PWM chip
* @chip: linux PWM chip representation
* @regs: base address of PWM chip
* @clk_top: the top clock generator
* @clk_main: the clock used by PWM core
* @clk_pwms: the clock used by each PWM channel
* @clk_freq: the fix clock frequency of legacy MIPS SoC
* @soc: pointer to chip's platform data
*/
struct pwm_mediatek_chip {
struct pwm_chip chip;
void __iomem *regs;
struct clk *clk_top;
struct clk *clk_main;
struct clk **clk_pwms;
const struct pwm_mediatek_of_data *soc;
};
static const unsigned int mtk_pwm_reg_offset_v1[] = {
0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
};
static const unsigned int mtk_pwm_reg_offset_v2[] = {
0x0080, 0x00c0, 0x0100, 0x0140, 0x0180, 0x01c0, 0x0200, 0x0240
};
static inline struct pwm_mediatek_chip *
to_pwm_mediatek_chip(struct pwm_chip *chip)
{
return container_of(chip, struct pwm_mediatek_chip, chip);
}
static int pwm_mediatek_clk_enable(struct pwm_chip *chip,
struct pwm_device *pwm)
{
struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
int ret;
ret = clk_prepare_enable(pc->clk_top);
if (ret < 0)
return ret;
ret = clk_prepare_enable(pc->clk_main);
if (ret < 0)
goto disable_clk_top;
ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]);
if (ret < 0)
goto disable_clk_main;
return 0;
disable_clk_main:
clk_disable_unprepare(pc->clk_main);
disable_clk_top:
clk_disable_unprepare(pc->clk_top);
return ret;
}
static void pwm_mediatek_clk_disable(struct pwm_chip *chip,
struct pwm_device *pwm)
{
struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]);
clk_disable_unprepare(pc->clk_main);
clk_disable_unprepare(pc->clk_top);
}
static inline void pwm_mediatek_writel(struct pwm_mediatek_chip *chip,
unsigned int num, unsigned int offset,
u32 value)
{
writel(value, chip->regs + chip->soc->reg_offset[num] + offset);
}
static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
reg_thres = PWMTHRES;
u64 resolution;
int ret;
ret = pwm_mediatek_clk_enable(chip, pwm);
if (ret < 0)
return ret;
/* Make sure we use the bus clock and not the 26MHz clock */
if (pc->soc->has_ck_26m_sel)
writel(0, pc->regs + PWM_CK_26M_SEL);
/* Using resolution in picosecond gets accuracy higher */
resolution = (u64)NSEC_PER_SEC * 1000;
do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));
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) {
pwm_mediatek_clk_disable(chip, pwm);
dev_err(chip->dev, "period of %d ns not supported\n", period_ns);
return -EINVAL;
}
if (pc->soc->pwm45_fixup && pwm->hwpwm > 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);
pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
pwm_mediatek_clk_disable(chip, pwm);
return 0;
}
static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
u32 value;
int ret;
ret = pwm_mediatek_clk_enable(chip, pwm);
if (ret < 0)
return ret;
value = readl(pc->regs);
value |= BIT(pwm->hwpwm);
writel(value, pc->regs);
return 0;
}
static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
u32 value;
value = readl(pc->regs);
value &= ~BIT(pwm->hwpwm);
writel(value, pc->regs);
pwm_mediatek_clk_disable(chip, pwm);
}
static int pwm_mediatek_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
int err;
if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL;
if (!state->enabled) {
if (pwm->state.enabled)
pwm_mediatek_disable(chip, pwm);
return 0;
}
err = pwm_mediatek_config(chip, pwm, state->duty_cycle, state->period);
if (err)
return err;
if (!pwm->state.enabled)
err = pwm_mediatek_enable(chip, pwm);
return err;
}
static const struct pwm_ops pwm_mediatek_ops = {
.apply = pwm_mediatek_apply,
};
static int pwm_mediatek_probe(struct platform_device *pdev)
{
struct pwm_mediatek_chip *pc;
unsigned int i;
int ret;
pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
return -ENOMEM;
pc->soc = of_device_get_match_data(&pdev->dev);
pc->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(pc->regs))
return PTR_ERR(pc->regs);
pc->clk_pwms = devm_kmalloc_array(&pdev->dev, pc->soc->num_pwms,
sizeof(*pc->clk_pwms), GFP_KERNEL);
if (!pc->clk_pwms)
return -ENOMEM;
pc->clk_top = devm_clk_get(&pdev->dev, "top");
if (IS_ERR(pc->clk_top))
return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_top),
"Failed to get top clock\n");
pc->clk_main = devm_clk_get(&pdev->dev, "main");
if (IS_ERR(pc->clk_main))
return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_main),
"Failed to get main clock\n");
for (i = 0; i < pc->soc->num_pwms; i++) {
char name[8];
snprintf(name, sizeof(name), "pwm%d", i + 1);
pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
if (IS_ERR(pc->clk_pwms[i]))
return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_pwms[i]),
"Failed to get %s clock\n", name);
}
pc->chip.dev = &pdev->dev;
pc->chip.ops = &pwm_mediatek_ops;
pc->chip.npwm = pc->soc->num_pwms;
ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
if (ret < 0)
return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");
return 0;
}
static const struct pwm_mediatek_of_data mt2712_pwm_data = {
.num_pwms = 8,
.pwm45_fixup = false,
.has_ck_26m_sel = false,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt6795_pwm_data = {
.num_pwms = 7,
.pwm45_fixup = false,
.has_ck_26m_sel = false,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt7622_pwm_data = {
.num_pwms = 6,
.pwm45_fixup = false,
.has_ck_26m_sel = true,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt7623_pwm_data = {
.num_pwms = 5,
.pwm45_fixup = true,
.has_ck_26m_sel = false,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt7628_pwm_data = {
.num_pwms = 4,
.pwm45_fixup = true,
.has_ck_26m_sel = false,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt7629_pwm_data = {
.num_pwms = 1,
.pwm45_fixup = false,
.has_ck_26m_sel = false,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt7981_pwm_data = {
.num_pwms = 3,
.pwm45_fixup = false,
.has_ck_26m_sel = true,
.reg_offset = mtk_pwm_reg_offset_v2,
};
static const struct pwm_mediatek_of_data mt7986_pwm_data = {
.num_pwms = 2,
.pwm45_fixup = false,
.has_ck_26m_sel = true,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt8183_pwm_data = {
.num_pwms = 4,
.pwm45_fixup = false,
.has_ck_26m_sel = true,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt8365_pwm_data = {
.num_pwms = 3,
.pwm45_fixup = false,
.has_ck_26m_sel = true,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct pwm_mediatek_of_data mt8516_pwm_data = {
.num_pwms = 5,
.pwm45_fixup = false,
.has_ck_26m_sel = true,
.reg_offset = mtk_pwm_reg_offset_v1,
};
static const struct of_device_id pwm_mediatek_of_match[] = {
{ .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
{ .compatible = "mediatek,mt6795-pwm", .data = &mt6795_pwm_data },
{ .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
{ .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
{ .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
{ .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data },
{ .compatible = "mediatek,mt7981-pwm", .data = &mt7981_pwm_data },
{ .compatible = "mediatek,mt7986-pwm", .data = &mt7986_pwm_data },
{ .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data },
{ .compatible = "mediatek,mt8365-pwm", .data = &mt8365_pwm_data },
{ .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data },
{ },
};
MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match);
static struct platform_driver pwm_mediatek_driver = {
.driver = {
.name = "pwm-mediatek",
.of_match_table = pwm_mediatek_of_match,
},
.probe = pwm_mediatek_probe,
};
module_platform_driver(pwm_mediatek_driver);
MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
MODULE_LICENSE("GPL v2");