linux/drivers/pwm/pwm-clps711x.c
Uwe Kleine-König 384461abca pwm: Manage owner assignment implicitly for drivers
Instead of requiring each driver to care for assigning the owner member
of struct pwm_ops, handle that implicitly using a macro. Note that the
owner member has to be moved to struct pwm_chip, as the ops structure
usually lives in read-only memory and so cannot be modified.

The upside is that new low level drivers cannot forget the assignment and
save one line each. The pwm-crc driver didn't assign .owner, that's not
a problem in practice though as the driver cannot be compiled as a
module.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti
Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip
Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld
Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230804142707.412137-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-10-13 10:07:17 +02:00

131 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,
};
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");