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	This prepares the pwm-clps711x driver to further changes of the pwm core outlined in the commit introducing devm_pwmchip_alloc(). There is no intended semantical change and the driver should behave as before. Link: https://lore.kernel.org/r/334e633bb8e4c26dc59883b068466387769b65f9.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
		
			
				
	
	
		
			118 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			118 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0+
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/*
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 * Cirrus Logic CLPS711X PWM driver
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 * Author: Alexander Shiyan <shc_work@mail.ru>
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 */
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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struct clps711x_chip {
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	void __iomem *pmpcon;
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	struct clk *clk;
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	spinlock_t lock;
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};
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static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)
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{
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	return pwmchip_get_drvdata(chip);
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}
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static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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	struct clps711x_chip *priv = to_clps711x_chip(chip);
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	unsigned int freq = clk_get_rate(priv->clk);
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	if (!freq)
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		return -EINVAL;
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	/* Store constant period value */
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	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
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	return 0;
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}
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static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
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			      const struct pwm_state *state)
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{
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	struct clps711x_chip *priv = to_clps711x_chip(chip);
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	/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
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	u32 shift = (pwm->hwpwm + 1) * 4;
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	unsigned long flags;
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	u32 pmpcon, val;
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	if (state->polarity != PWM_POLARITY_NORMAL)
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		return -EINVAL;
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	if (state->period != pwm->args.period)
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		return -EINVAL;
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	if (state->enabled)
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		val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period);
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	else
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		val = 0;
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	spin_lock_irqsave(&priv->lock, flags);
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	pmpcon = readl(priv->pmpcon);
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	pmpcon &= ~(0xf << shift);
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	pmpcon |= val << shift;
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	writel(pmpcon, priv->pmpcon);
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	spin_unlock_irqrestore(&priv->lock, flags);
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	return 0;
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}
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static const struct pwm_ops clps711x_pwm_ops = {
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	.request = clps711x_pwm_request,
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	.apply = clps711x_pwm_apply,
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};
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static int clps711x_pwm_probe(struct platform_device *pdev)
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{
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	struct pwm_chip *chip;
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	struct clps711x_chip *priv;
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	chip = devm_pwmchip_alloc(&pdev->dev, 2, sizeof(*priv));
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	if (IS_ERR(chip))
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		return PTR_ERR(chip);
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	priv = to_clps711x_chip(chip);
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	priv->pmpcon = devm_platform_ioremap_resource(pdev, 0);
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	if (IS_ERR(priv->pmpcon))
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		return PTR_ERR(priv->pmpcon);
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	priv->clk = devm_clk_get(&pdev->dev, NULL);
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	if (IS_ERR(priv->clk))
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		return PTR_ERR(priv->clk);
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	chip->ops = &clps711x_pwm_ops;
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	spin_lock_init(&priv->lock);
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	return devm_pwmchip_add(&pdev->dev, chip);
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}
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static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
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	{ .compatible = "cirrus,ep7209-pwm", },
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	{ }
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};
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MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
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static struct platform_driver clps711x_pwm_driver = {
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	.driver = {
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		.name = "clps711x-pwm",
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		.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
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	},
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	.probe = clps711x_pwm_probe,
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};
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module_platform_driver(clps711x_pwm_driver);
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MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
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MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
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MODULE_LICENSE("GPL");
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