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 void __iomem *pmpcon; 16 struct clk *clk; 17 spinlock_t lock; 18 }; 19 20 static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip) 21 { 22 return pwmchip_get_drvdata(chip); 23 } 24 25 static 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 39 static 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 else 57 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 71 static const struct pwm_ops clps711x_pwm_ops = { 72 .request = clps711x_pwm_request, 73 .apply = clps711x_pwm_apply, 74 }; 75 76 static 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 } 100 101 static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = { 102 { .compatible = "cirrus,ep7209-pwm", }, 103 { } 104 }; 105 MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids); 106 107 static 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 }; 114 module_platform_driver(clps711x_pwm_driver); 115 116 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); 117 MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver"); 118 MODULE_LICENSE("GPL"); 119