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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Cirrus Logic CLPS711X PWM driver4 * Author: Alexander Shiyan <shc_work@mail.ru>5 */6 7#include <linux/clk.h>8#include <linux/io.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/platform_device.h>12#include <linux/pwm.h>13 14struct clps711x_chip {15 void __iomem *pmpcon;16 struct clk *clk;17 spinlock_t lock;18};19 20static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)21{22 return pwmchip_get_drvdata(chip);23}24 25static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)26{27 struct clps711x_chip *priv = to_clps711x_chip(chip);28 unsigned int freq = clk_get_rate(priv->clk);29 30 if (!freq)31 return -EINVAL;32 33 /* Store constant period value */34 pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);35 36 return 0;37}38 39static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,40 const struct pwm_state *state)41{42 struct clps711x_chip *priv = to_clps711x_chip(chip);43 /* PWM0 - bits 4..7, PWM1 - bits 8..11 */44 u32 shift = (pwm->hwpwm + 1) * 4;45 unsigned long flags;46 u32 pmpcon, val;47 48 if (state->polarity != PWM_POLARITY_NORMAL)49 return -EINVAL;50 51 if (state->period != pwm->args.period)52 return -EINVAL;53 54 if (state->enabled)55 val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period);56 else57 val = 0;58 59 spin_lock_irqsave(&priv->lock, flags);60 61 pmpcon = readl(priv->pmpcon);62 pmpcon &= ~(0xf << shift);63 pmpcon |= val << shift;64 writel(pmpcon, priv->pmpcon);65 66 spin_unlock_irqrestore(&priv->lock, flags);67 68 return 0;69}70 71static const struct pwm_ops clps711x_pwm_ops = {72 .request = clps711x_pwm_request,73 .apply = clps711x_pwm_apply,74};75 76static int clps711x_pwm_probe(struct platform_device *pdev)77{78 struct pwm_chip *chip;79 struct clps711x_chip *priv;80 81 chip = devm_pwmchip_alloc(&pdev->dev, 2, sizeof(*priv));82 if (IS_ERR(chip))83 return PTR_ERR(chip);84 priv = to_clps711x_chip(chip);85 86 priv->pmpcon = devm_platform_ioremap_resource(pdev, 0);87 if (IS_ERR(priv->pmpcon))88 return PTR_ERR(priv->pmpcon);89 90 priv->clk = devm_clk_get(&pdev->dev, NULL);91 if (IS_ERR(priv->clk))92 return PTR_ERR(priv->clk);93 94 chip->ops = &clps711x_pwm_ops;95 96 spin_lock_init(&priv->lock);97 98 return devm_pwmchip_add(&pdev->dev, chip);99}100 101static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {102 { .compatible = "cirrus,ep7209-pwm", },103 { }104};105MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);106 107static struct platform_driver clps711x_pwm_driver = {108 .driver = {109 .name = "clps711x-pwm",110 .of_match_table = of_match_ptr(clps711x_pwm_dt_ids),111 },112 .probe = clps711x_pwm_probe,113};114module_platform_driver(clps711x_pwm_driver);115 116MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");117MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");118MODULE_LICENSE("GPL");119