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 14 struct clps711x_chip { 15 struct pwm_chip chip; 16 void __iomem *pmpcon; 17 struct clk *clk; 18 spinlock_t lock; 19 }; 20 21 static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip) 22 { 23 return container_of(chip, struct clps711x_chip, chip); 24 } 25 26 static 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 40 static 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 72 static const struct pwm_ops clps711x_pwm_ops = { 73 .request = clps711x_pwm_request, 74 .apply = clps711x_pwm_apply, 75 .owner = THIS_MODULE, 76 }; 77 78 static 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 87 static 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 } 113 114 static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { 115 { .compatible = "cirrus,ep7209-pwm", }, 116 { } 117 }; 118 MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids); 119 120 static 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 }; 127 module_platform_driver(clps711x_pwm_driver); 128 129 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); 130 MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver"); 131 MODULE_LICENSE("GPL"); 132