132 lines
3.1 KiB
C
132 lines
3.1 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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struct pwm_chip 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 container_of(chip, struct clps711x_chip, 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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.owner = THIS_MODULE,
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};
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static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip,
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const struct of_phandle_args *args)
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{
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if (args->args[0] >= chip->npwm)
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return ERR_PTR(-EINVAL);
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return pwm_request_from_chip(chip, args->args[0], NULL);
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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 clps711x_chip *priv;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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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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priv->chip.ops = &clps711x_pwm_ops;
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priv->chip.dev = &pdev->dev;
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priv->chip.npwm = 2;
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priv->chip.of_xlate = clps711x_pwm_xlate;
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priv->chip.of_pwm_n_cells = 1;
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spin_lock_init(&priv->lock);
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return devm_pwmchip_add(&pdev->dev, &priv->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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