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![Alexander Shiyan](/assets/img/avatar_default.png)
This patch changes the compatibility string to match with the smallest supported chip (EP7209). Since the DT-support for this CPU is not yet announced, this change is safe. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
175 lines
4.3 KiB
C
175 lines
4.3 KiB
C
/*
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* Cirrus Logic CLPS711X PWM driver
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*
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* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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 void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v)
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{
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/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
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u32 shift = (n + 1) * 4;
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unsigned long flags;
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u32 tmp;
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spin_lock_irqsave(&priv->lock, flags);
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tmp = readl(priv->pmpcon);
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tmp &= ~(0xf << shift);
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tmp |= v << shift;
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writel(tmp, priv->pmpcon);
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spin_unlock_irqrestore(&priv->lock, flags);
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}
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static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
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{
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/* Duty cycle 0..15 max */
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return DIV_ROUND_CLOSEST(v * 0xf, pwm_get_period(pwm));
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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_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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struct clps711x_chip *priv = to_clps711x_chip(chip);
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unsigned int duty;
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if (period_ns != pwm_get_period(pwm))
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return -EINVAL;
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duty = clps711x_get_duty(pwm, duty_ns);
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clps711x_pwm_update_val(priv, pwm->hwpwm, duty);
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return 0;
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}
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static int clps711x_pwm_enable(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 duty;
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duty = clps711x_get_duty(pwm, pwm_get_duty_cycle(pwm));
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clps711x_pwm_update_val(priv, pwm->hwpwm, duty);
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return 0;
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}
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static void clps711x_pwm_disable(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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clps711x_pwm_update_val(priv, pwm->hwpwm, 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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.config = clps711x_pwm_config,
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.enable = clps711x_pwm_enable,
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.disable = clps711x_pwm_disable,
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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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struct resource *res;
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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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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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priv->pmpcon = devm_ioremap_resource(&pdev->dev, res);
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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.base = -1;
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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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platform_set_drvdata(pdev, priv);
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return pwmchip_add(&priv->chip);
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}
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static int clps711x_pwm_remove(struct platform_device *pdev)
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{
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struct clps711x_chip *priv = platform_get_drvdata(pdev);
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return pwmchip_remove(&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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.remove = clps711x_pwm_remove,
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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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