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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 | /* * Cirrus Logic CLPS711X PWM driver * * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include <linux/clk.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pwm.h> struct clps711x_chip { struct pwm_chip chip; void __iomem *pmpcon; struct clk *clk; spinlock_t lock; }; static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip) { return container_of(chip, struct clps711x_chip, chip); } static void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v) { /* PWM0 - bits 4..7, PWM1 - bits 8..11 */ u32 shift = (n + 1) * 4; unsigned long flags; u32 tmp; spin_lock_irqsave(&priv->lock, flags); tmp = readl(priv->pmpcon); tmp &= ~(0xf << shift); tmp |= v << shift; writel(tmp, priv->pmpcon); spin_unlock_irqrestore(&priv->lock, flags); } static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v) { /* Duty cycle 0..15 max */ return DIV_ROUND_CLOSEST(v * 0xf, pwm_get_period(pwm)); } static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { struct clps711x_chip *priv = to_clps711x_chip(chip); unsigned int freq = clk_get_rate(priv->clk); if (!freq) return -EINVAL; /* Store constant period value */ pwm_set_period(pwm, DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq)); return 0; } static int clps711x_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct clps711x_chip *priv = to_clps711x_chip(chip); unsigned int duty; if (period_ns != pwm_get_period(pwm)) return -EINVAL; duty = clps711x_get_duty(pwm, duty_ns); clps711x_pwm_update_val(priv, pwm->hwpwm, duty); return 0; } static int clps711x_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct clps711x_chip *priv = to_clps711x_chip(chip); unsigned int duty; duty = clps711x_get_duty(pwm, pwm_get_duty_cycle(pwm)); clps711x_pwm_update_val(priv, pwm->hwpwm, duty); return 0; } static void clps711x_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct clps711x_chip *priv = to_clps711x_chip(chip); clps711x_pwm_update_val(priv, pwm->hwpwm, 0); } static const struct pwm_ops clps711x_pwm_ops = { .request = clps711x_pwm_request, .config = clps711x_pwm_config, .enable = clps711x_pwm_enable, .disable = clps711x_pwm_disable, .owner = THIS_MODULE, }; static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip, const struct of_phandle_args *args) { if (args->args[0] >= chip->npwm) return ERR_PTR(-EINVAL); return pwm_request_from_chip(chip, args->args[0], NULL); } static int clps711x_pwm_probe(struct platform_device *pdev) { struct clps711x_chip *priv; struct resource *res; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); priv->pmpcon = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(priv->pmpcon)) return PTR_ERR(priv->pmpcon); priv->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(priv->clk)) return PTR_ERR(priv->clk); priv->chip.ops = &clps711x_pwm_ops; priv->chip.dev = &pdev->dev; priv->chip.base = -1; priv->chip.npwm = 2; priv->chip.of_xlate = clps711x_pwm_xlate; priv->chip.of_pwm_n_cells = 1; spin_lock_init(&priv->lock); platform_set_drvdata(pdev, priv); return pwmchip_add(&priv->chip); } static int clps711x_pwm_remove(struct platform_device *pdev) { struct clps711x_chip *priv = platform_get_drvdata(pdev); return pwmchip_remove(&priv->chip); } static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { { .compatible = "cirrus,clps711x-pwm", }, { } }; MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids); static struct platform_driver clps711x_pwm_driver = { .driver = { .name = "clps711x-pwm", .of_match_table = of_match_ptr(clps711x_pwm_dt_ids), }, .probe = clps711x_pwm_probe, .remove = clps711x_pwm_remove, }; module_platform_driver(clps711x_pwm_driver); MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver"); MODULE_LICENSE("GPL"); |