mirror of
https://github.com/torvalds/linux.git
synced 2024-11-26 22:21:42 +00:00
4225cd01d3
To eventually get rid of all legacy drivers convert this driver to the modern world implementing .apply(). This fixes a small issue in clps711x_get_duty() en passant: the multiplication v * 0xf might have overflown. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
132 lines
3.1 KiB
C
132 lines
3.1 KiB
C
// 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,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
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;
|
|
priv->chip.of_pwm_n_cells = 1;
|
|
|
|
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");
|