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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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f0d91b16dc
The pwm core serializes calls to .apply(), so the spinlock adds no additional protection. Disabling the irq is also irrelevant as the driver isn't an atomic one and so the callbacks cannot be called from atomic context. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Link: https://lore.kernel.org/r/d4931dc0c0d657d80722cfe7d97cb4fb4ccec90e.1750788649.git.u.kleine-koenig@baylibre.com Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
110 lines
2.5 KiB
C
110 lines
2.5 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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};
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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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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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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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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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return devm_pwmchip_add(&pdev->dev, chip);
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}
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static const struct of_device_id 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 = 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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