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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 | // SPDX-License-Identifier: GPL-2.0+ /* * Cirrus Logic CLPS711X PWM driver * Author: Alexander Shiyan <shc_work@mail.ru> */ #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 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->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq); return 0; } static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { struct clps711x_chip *priv = to_clps711x_chip(chip); /* PWM0 - bits 4..7, PWM1 - bits 8..11 */ u32 shift = (pwm->hwpwm + 1) * 4; unsigned long flags; u32 pmpcon, val; if (state->polarity != PWM_POLARITY_NORMAL) return -EINVAL; if (state->period != pwm->args.period) return -EINVAL; if (state->enabled) val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period); else val = 0; spin_lock_irqsave(&priv->lock, flags); pmpcon = readl(priv->pmpcon); pmpcon &= ~(0xf << shift); pmpcon |= val << shift; writel(pmpcon, priv->pmpcon); spin_unlock_irqrestore(&priv->lock, flags); return 0; } static const struct pwm_ops clps711x_pwm_ops = { .request = clps711x_pwm_request, .apply = clps711x_pwm_apply, .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; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->pmpcon = devm_platform_ioremap_resource(pdev, 0); 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.npwm = 2; priv->chip.of_xlate = clps711x_pwm_xlate; priv->chip.of_pwm_n_cells = 1; spin_lock_init(&priv->lock); return devm_pwmchip_add(&pdev->dev, &priv->chip); } static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { { .compatible = "cirrus,ep7209-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, }; module_platform_driver(clps711x_pwm_driver); MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver"); MODULE_LICENSE("GPL"); |