303 lines
7.3 KiB
C
303 lines
7.3 KiB
C
/*
|
|
* Marvell Berlin PWM driver
|
|
*
|
|
* Copyright (C) 2015 Marvell Technology Group Ltd.
|
|
*
|
|
* Author: Antoine Tenart <antoine.tenart@free-electrons.com>
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public
|
|
* License version 2. This program is licensed "as is" without any
|
|
* warranty of any kind, whether express or implied.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pwm.h>
|
|
#include <linux/slab.h>
|
|
|
|
#define BERLIN_PWM_EN 0x0
|
|
#define BERLIN_PWM_ENABLE BIT(0)
|
|
#define BERLIN_PWM_CONTROL 0x4
|
|
#define BERLIN_PWM_PRESCALE_MASK 0x7
|
|
#define BERLIN_PWM_PRESCALE_MAX 4096
|
|
#define BERLIN_PWM_INVERT_POLARITY BIT(3)
|
|
#define BERLIN_PWM_DUTY 0x8
|
|
#define BERLIN_PWM_TCNT 0xc
|
|
#define BERLIN_PWM_MAX_TCNT 65535
|
|
|
|
struct berlin_pwm_channel {
|
|
u32 enable;
|
|
u32 ctrl;
|
|
u32 duty;
|
|
u32 tcnt;
|
|
};
|
|
|
|
struct berlin_pwm_chip {
|
|
struct pwm_chip chip;
|
|
struct clk *clk;
|
|
void __iomem *base;
|
|
};
|
|
|
|
static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
|
|
{
|
|
return container_of(chip, struct berlin_pwm_chip, chip);
|
|
}
|
|
|
|
static const u32 prescaler_table[] = {
|
|
1, 4, 8, 16, 64, 256, 1024, 4096
|
|
};
|
|
|
|
static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip,
|
|
unsigned int channel, unsigned long offset)
|
|
{
|
|
return readl_relaxed(chip->base + channel * 0x10 + offset);
|
|
}
|
|
|
|
static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
|
|
unsigned int channel, u32 value,
|
|
unsigned long offset)
|
|
{
|
|
writel_relaxed(value, chip->base + channel * 0x10 + offset);
|
|
}
|
|
|
|
static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct berlin_pwm_channel *channel;
|
|
|
|
channel = kzalloc(sizeof(*channel), GFP_KERNEL);
|
|
if (!channel)
|
|
return -ENOMEM;
|
|
|
|
return pwm_set_chip_data(pwm, channel);
|
|
}
|
|
|
|
static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
|
|
{
|
|
struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);
|
|
|
|
pwm_set_chip_data(pwm, NULL);
|
|
kfree(channel);
|
|
}
|
|
|
|
static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
|
|
int duty_ns, int period_ns)
|
|
{
|
|
struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
|
|
unsigned int prescale;
|
|
u32 value, duty, period;
|
|
u64 cycles, tmp;
|
|
|
|
cycles = clk_get_rate(pwm->clk);
|
|
cycles *= period_ns;
|
|
do_div(cycles, NSEC_PER_SEC);
|
|
|
|
for (prescale = 0; prescale < ARRAY_SIZE(prescaler_table); prescale++) {
|
|
tmp = cycles;
|
|
do_div(tmp, prescaler_table[prescale]);
|
|
|
|
if (tmp <= BERLIN_PWM_MAX_TCNT)
|
|
break;
|
|
}
|
|
|
|
if (tmp > BERLIN_PWM_MAX_TCNT)
|
|
return -ERANGE;
|
|
|
|
period = tmp;
|
|
cycles = tmp * duty_ns;
|
|
do_div(cycles, period_ns);
|
|
duty = cycles;
|
|
|
|
value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
|
|
value &= ~BERLIN_PWM_PRESCALE_MASK;
|
|
value |= prescale;
|
|
berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
|
|
|
|
berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY);
|
|
berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int berlin_pwm_set_polarity(struct pwm_chip *chip,
|
|
struct pwm_device *pwm_dev,
|
|
enum pwm_polarity polarity)
|
|
{
|
|
struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
|
|
u32 value;
|
|
|
|
value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
|
|
|
|
if (polarity == PWM_POLARITY_NORMAL)
|
|
value &= ~BERLIN_PWM_INVERT_POLARITY;
|
|
else
|
|
value |= BERLIN_PWM_INVERT_POLARITY;
|
|
|
|
berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev)
|
|
{
|
|
struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
|
|
u32 value;
|
|
|
|
value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
|
|
value |= BERLIN_PWM_ENABLE;
|
|
berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void berlin_pwm_disable(struct pwm_chip *chip,
|
|
struct pwm_device *pwm_dev)
|
|
{
|
|
struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
|
|
u32 value;
|
|
|
|
value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
|
|
value &= ~BERLIN_PWM_ENABLE;
|
|
berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
|
|
}
|
|
|
|
static const struct pwm_ops berlin_pwm_ops = {
|
|
.request = berlin_pwm_request,
|
|
.free = berlin_pwm_free,
|
|
.config = berlin_pwm_config,
|
|
.set_polarity = berlin_pwm_set_polarity,
|
|
.enable = berlin_pwm_enable,
|
|
.disable = berlin_pwm_disable,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static const struct of_device_id berlin_pwm_match[] = {
|
|
{ .compatible = "marvell,berlin-pwm" },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, berlin_pwm_match);
|
|
|
|
static int berlin_pwm_probe(struct platform_device *pdev)
|
|
{
|
|
struct berlin_pwm_chip *pwm;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
|
|
if (!pwm)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
pwm->base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(pwm->base))
|
|
return PTR_ERR(pwm->base);
|
|
|
|
pwm->clk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(pwm->clk))
|
|
return PTR_ERR(pwm->clk);
|
|
|
|
ret = clk_prepare_enable(pwm->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
pwm->chip.dev = &pdev->dev;
|
|
pwm->chip.ops = &berlin_pwm_ops;
|
|
pwm->chip.base = -1;
|
|
pwm->chip.npwm = 4;
|
|
pwm->chip.of_xlate = of_pwm_xlate_with_flags;
|
|
pwm->chip.of_pwm_n_cells = 3;
|
|
|
|
ret = pwmchip_add(&pwm->chip);
|
|
if (ret < 0) {
|
|
dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
|
|
clk_disable_unprepare(pwm->clk);
|
|
return ret;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, pwm);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int berlin_pwm_remove(struct platform_device *pdev)
|
|
{
|
|
struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
|
|
int ret;
|
|
|
|
ret = pwmchip_remove(&pwm->chip);
|
|
clk_disable_unprepare(pwm->clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int berlin_pwm_suspend(struct device *dev)
|
|
{
|
|
struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < pwm->chip.npwm; i++) {
|
|
struct berlin_pwm_channel *channel;
|
|
|
|
channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
|
|
if (!channel)
|
|
continue;
|
|
|
|
channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
|
|
channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
|
|
channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
|
|
channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
|
|
}
|
|
|
|
clk_disable_unprepare(pwm->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int berlin_pwm_resume(struct device *dev)
|
|
{
|
|
struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
|
|
unsigned int i;
|
|
int ret;
|
|
|
|
ret = clk_prepare_enable(pwm->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (i = 0; i < pwm->chip.npwm; i++) {
|
|
struct berlin_pwm_channel *channel;
|
|
|
|
channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
|
|
if (!channel)
|
|
continue;
|
|
|
|
berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);
|
|
berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);
|
|
berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);
|
|
berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
|
|
berlin_pwm_resume);
|
|
|
|
static struct platform_driver berlin_pwm_driver = {
|
|
.probe = berlin_pwm_probe,
|
|
.remove = berlin_pwm_remove,
|
|
.driver = {
|
|
.name = "berlin-pwm",
|
|
.of_match_table = berlin_pwm_match,
|
|
.pm = &berlin_pwm_pm_ops,
|
|
},
|
|
};
|
|
module_platform_driver(berlin_pwm_driver);
|
|
|
|
MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
|
|
MODULE_DESCRIPTION("Marvell Berlin PWM driver");
|
|
MODULE_LICENSE("GPL v2");
|