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// SPDX-License-Identifier: GPL-2.0+
/*
* Cirrus Logic CLPS711X PWM driver
* Author: Alexander Shiyan <shc_work@mail.ru>
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
struct clps711x_chip {
struct pwm_chip chip;
void __iomem *pmpcon;
struct clk *clk;
spinlock_t lock;
};
static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)
{
return container_of(chip, struct clps711x_chip, chip);
}
static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct clps711x_chip *priv = to_clps711x_chip(chip);
unsigned int freq = clk_get_rate(priv->clk);
if (!freq)
return -EINVAL;
/* Store constant period value */
pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
return 0;
}
static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct clps711x_chip *priv = to_clps711x_chip(chip);
/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
u32 shift = (pwm->hwpwm + 1) * 4;
unsigned long flags;
u32 pmpcon, val;
if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL;
if (state->period != pwm->args.period)
return -EINVAL;
if (state->enabled)
val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period);
else
val = 0;
spin_lock_irqsave(&priv->lock, flags);
pmpcon = readl(priv->pmpcon);
pmpcon &= ~(0xf << shift);
pmpcon |= val << shift;
writel(pmpcon, priv->pmpcon);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static const struct pwm_ops clps711x_pwm_ops = {
.request = clps711x_pwm_request,
.apply = clps711x_pwm_apply,
};
static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip,
const struct of_phandle_args *args)
{
if (args->args[0] >= chip->npwm)
return ERR_PTR(-EINVAL);
return pwm_request_from_chip(chip, args->args[0], NULL);
}
static int clps711x_pwm_probe(struct platform_device *pdev)
{
struct clps711x_chip *priv;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->pmpcon = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->pmpcon))
return PTR_ERR(priv->pmpcon);
priv->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
priv->chip.ops = &clps711x_pwm_ops;
priv->chip.dev = &pdev->dev;
priv->chip.npwm = 2;
priv->chip.of_xlate = clps711x_pwm_xlate;
spin_lock_init(&priv->lock);
return devm_pwmchip_add(&pdev->dev, &priv->chip);
}
static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
{ .compatible = "cirrus,ep7209-pwm", },
{ }
};
MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
static struct platform_driver clps711x_pwm_driver = {
.driver = {
.name = "clps711x-pwm",
.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
},
.probe = clps711x_pwm_probe,
};
module_platform_driver(clps711x_pwm_driver);
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
MODULE_LICENSE("GPL");
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