linux/drivers/pwm/pwm-hibvt.c
Uwe Kleine-König 1b6d6ce5a5 pwm: hibvt: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-03-30 16:26:29 +02:00

289 lines
7.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PWM Controller Driver for HiSilicon BVT SoCs
*
* Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/reset.h>
#define PWM_CFG0_ADDR(x) (((x) * 0x20) + 0x0)
#define PWM_CFG1_ADDR(x) (((x) * 0x20) + 0x4)
#define PWM_CFG2_ADDR(x) (((x) * 0x20) + 0x8)
#define PWM_CTRL_ADDR(x) (((x) * 0x20) + 0xC)
#define PWM_ENABLE_SHIFT 0
#define PWM_ENABLE_MASK BIT(0)
#define PWM_POLARITY_SHIFT 1
#define PWM_POLARITY_MASK BIT(1)
#define PWM_KEEP_SHIFT 2
#define PWM_KEEP_MASK BIT(2)
#define PWM_PERIOD_MASK GENMASK(31, 0)
#define PWM_DUTY_MASK GENMASK(31, 0)
struct hibvt_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
void __iomem *base;
struct reset_control *rstc;
const struct hibvt_pwm_soc *soc;
};
struct hibvt_pwm_soc {
u32 num_pwms;
bool quirk_force_enable;
};
static const struct hibvt_pwm_soc hi3516cv300_soc_info = {
.num_pwms = 4,
};
static const struct hibvt_pwm_soc hi3519v100_soc_info = {
.num_pwms = 8,
};
static const struct hibvt_pwm_soc hi3559v100_shub_soc_info = {
.num_pwms = 8,
.quirk_force_enable = true,
};
static const struct hibvt_pwm_soc hi3559v100_soc_info = {
.num_pwms = 2,
.quirk_force_enable = true,
};
static inline struct hibvt_pwm_chip *to_hibvt_pwm_chip(struct pwm_chip *chip)
{
return container_of(chip, struct hibvt_pwm_chip, chip);
}
static void hibvt_pwm_set_bits(void __iomem *base, u32 offset,
u32 mask, u32 data)
{
void __iomem *address = base + offset;
u32 value;
value = readl(address);
value &= ~mask;
value |= (data & mask);
writel(value, address);
}
static void hibvt_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
PWM_ENABLE_MASK, 0x1);
}
static void hibvt_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
PWM_ENABLE_MASK, 0x0);
}
static void hibvt_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_cycle_ns, int period_ns)
{
struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
u32 freq, period, duty;
freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
period = div_u64(freq * period_ns, 1000);
duty = div_u64(period * duty_cycle_ns, period_ns);
hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG0_ADDR(pwm->hwpwm),
PWM_PERIOD_MASK, period);
hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG1_ADDR(pwm->hwpwm),
PWM_DUTY_MASK, duty);
}
static void hibvt_pwm_set_polarity(struct pwm_chip *chip,
struct pwm_device *pwm,
enum pwm_polarity polarity)
{
struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
if (polarity == PWM_POLARITY_INVERSED)
hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
PWM_POLARITY_MASK, (0x1 << PWM_POLARITY_SHIFT));
else
hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
PWM_POLARITY_MASK, (0x0 << PWM_POLARITY_SHIFT));
}
static int hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_state *state)
{
struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
void __iomem *base;
u32 freq, value;
freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
base = hi_pwm_chip->base;
value = readl(base + PWM_CFG0_ADDR(pwm->hwpwm));
state->period = div_u64(value * 1000, freq);
value = readl(base + PWM_CFG1_ADDR(pwm->hwpwm));
state->duty_cycle = div_u64(value * 1000, freq);
value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm));
state->enabled = (PWM_ENABLE_MASK & value);
state->polarity = (PWM_POLARITY_MASK & value) ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
return 0;
}
static int hibvt_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
if (state->polarity != pwm->state.polarity)
hibvt_pwm_set_polarity(chip, pwm, state->polarity);
if (state->period != pwm->state.period ||
state->duty_cycle != pwm->state.duty_cycle) {
hibvt_pwm_config(chip, pwm, state->duty_cycle, state->period);
/*
* Some implementations require the PWM to be enabled twice
* each time the duty cycle is refreshed.
*/
if (hi_pwm_chip->soc->quirk_force_enable && state->enabled)
hibvt_pwm_enable(chip, pwm);
}
if (state->enabled != pwm->state.enabled) {
if (state->enabled)
hibvt_pwm_enable(chip, pwm);
else
hibvt_pwm_disable(chip, pwm);
}
return 0;
}
static const struct pwm_ops hibvt_pwm_ops = {
.get_state = hibvt_pwm_get_state,
.apply = hibvt_pwm_apply,
.owner = THIS_MODULE,
};
static int hibvt_pwm_probe(struct platform_device *pdev)
{
const struct hibvt_pwm_soc *soc =
of_device_get_match_data(&pdev->dev);
struct hibvt_pwm_chip *pwm_chip;
int ret, i;
pwm_chip = devm_kzalloc(&pdev->dev, sizeof(*pwm_chip), GFP_KERNEL);
if (pwm_chip == NULL)
return -ENOMEM;
pwm_chip->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pwm_chip->clk)) {
dev_err(&pdev->dev, "getting clock failed with %ld\n",
PTR_ERR(pwm_chip->clk));
return PTR_ERR(pwm_chip->clk);
}
pwm_chip->chip.ops = &hibvt_pwm_ops;
pwm_chip->chip.dev = &pdev->dev;
pwm_chip->chip.npwm = soc->num_pwms;
pwm_chip->soc = soc;
pwm_chip->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(pwm_chip->base))
return PTR_ERR(pwm_chip->base);
ret = clk_prepare_enable(pwm_chip->clk);
if (ret < 0)
return ret;
pwm_chip->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (IS_ERR(pwm_chip->rstc)) {
clk_disable_unprepare(pwm_chip->clk);
return PTR_ERR(pwm_chip->rstc);
}
reset_control_assert(pwm_chip->rstc);
msleep(30);
reset_control_deassert(pwm_chip->rstc);
ret = pwmchip_add(&pwm_chip->chip);
if (ret < 0) {
clk_disable_unprepare(pwm_chip->clk);
return ret;
}
for (i = 0; i < pwm_chip->chip.npwm; i++) {
hibvt_pwm_set_bits(pwm_chip->base, PWM_CTRL_ADDR(i),
PWM_KEEP_MASK, (0x1 << PWM_KEEP_SHIFT));
}
platform_set_drvdata(pdev, pwm_chip);
return 0;
}
static void hibvt_pwm_remove(struct platform_device *pdev)
{
struct hibvt_pwm_chip *pwm_chip;
pwm_chip = platform_get_drvdata(pdev);
pwmchip_remove(&pwm_chip->chip);
reset_control_assert(pwm_chip->rstc);
msleep(30);
reset_control_deassert(pwm_chip->rstc);
clk_disable_unprepare(pwm_chip->clk);
}
static const struct of_device_id hibvt_pwm_of_match[] = {
{ .compatible = "hisilicon,hi3516cv300-pwm",
.data = &hi3516cv300_soc_info },
{ .compatible = "hisilicon,hi3519v100-pwm",
.data = &hi3519v100_soc_info },
{ .compatible = "hisilicon,hi3559v100-shub-pwm",
.data = &hi3559v100_shub_soc_info },
{ .compatible = "hisilicon,hi3559v100-pwm",
.data = &hi3559v100_soc_info },
{ }
};
MODULE_DEVICE_TABLE(of, hibvt_pwm_of_match);
static struct platform_driver hibvt_pwm_driver = {
.driver = {
.name = "hibvt-pwm",
.of_match_table = hibvt_pwm_of_match,
},
.probe = hibvt_pwm_probe,
.remove_new = hibvt_pwm_remove,
};
module_platform_driver(hibvt_pwm_driver);
MODULE_AUTHOR("Jian Yuan");
MODULE_DESCRIPTION("HiSilicon BVT SoCs PWM driver");
MODULE_LICENSE("GPL");