cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pwm-clps711x.c (3150B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * Cirrus Logic CLPS711X PWM driver
      4 * 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	struct pwm_chip chip;
     16	void __iomem *pmpcon;
     17	struct clk *clk;
     18	spinlock_t lock;
     19};
     20
     21static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)
     22{
     23	return container_of(chip, struct clps711x_chip, chip);
     24}
     25
     26static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
     27{
     28	struct clps711x_chip *priv = to_clps711x_chip(chip);
     29	unsigned int freq = clk_get_rate(priv->clk);
     30
     31	if (!freq)
     32		return -EINVAL;
     33
     34	/* Store constant period value */
     35	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
     36
     37	return 0;
     38}
     39
     40static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
     41			      const struct pwm_state *state)
     42{
     43	struct clps711x_chip *priv = to_clps711x_chip(chip);
     44	/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
     45	u32 shift = (pwm->hwpwm + 1) * 4;
     46	unsigned long flags;
     47	u32 pmpcon, val;
     48
     49	if (state->polarity != PWM_POLARITY_NORMAL)
     50		return -EINVAL;
     51
     52	if (state->period != pwm->args.period)
     53		return -EINVAL;
     54
     55	if (state->enabled)
     56		val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period);
     57	else
     58		val = 0;
     59
     60	spin_lock_irqsave(&priv->lock, flags);
     61
     62	pmpcon = readl(priv->pmpcon);
     63	pmpcon &= ~(0xf << shift);
     64	pmpcon |= val << shift;
     65	writel(pmpcon, priv->pmpcon);
     66
     67	spin_unlock_irqrestore(&priv->lock, flags);
     68
     69	return 0;
     70}
     71
     72static const struct pwm_ops clps711x_pwm_ops = {
     73	.request = clps711x_pwm_request,
     74	.apply = clps711x_pwm_apply,
     75	.owner = THIS_MODULE,
     76};
     77
     78static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip,
     79					     const struct of_phandle_args *args)
     80{
     81	if (args->args[0] >= chip->npwm)
     82		return ERR_PTR(-EINVAL);
     83
     84	return pwm_request_from_chip(chip, args->args[0], NULL);
     85}
     86
     87static int clps711x_pwm_probe(struct platform_device *pdev)
     88{
     89	struct clps711x_chip *priv;
     90
     91	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
     92	if (!priv)
     93		return -ENOMEM;
     94
     95	priv->pmpcon = devm_platform_ioremap_resource(pdev, 0);
     96	if (IS_ERR(priv->pmpcon))
     97		return PTR_ERR(priv->pmpcon);
     98
     99	priv->clk = devm_clk_get(&pdev->dev, NULL);
    100	if (IS_ERR(priv->clk))
    101		return PTR_ERR(priv->clk);
    102
    103	priv->chip.ops = &clps711x_pwm_ops;
    104	priv->chip.dev = &pdev->dev;
    105	priv->chip.npwm = 2;
    106	priv->chip.of_xlate = clps711x_pwm_xlate;
    107	priv->chip.of_pwm_n_cells = 1;
    108
    109	spin_lock_init(&priv->lock);
    110
    111	return devm_pwmchip_add(&pdev->dev, &priv->chip);
    112}
    113
    114static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
    115	{ .compatible = "cirrus,ep7209-pwm", },
    116	{ }
    117};
    118MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
    119
    120static struct platform_driver clps711x_pwm_driver = {
    121	.driver = {
    122		.name = "clps711x-pwm",
    123		.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
    124	},
    125	.probe = clps711x_pwm_probe,
    126};
    127module_platform_driver(clps711x_pwm_driver);
    128
    129MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
    130MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
    131MODULE_LICENSE("GPL");