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 }; 18 19 static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip) 20 { 21 return pwmchip_get_drvdata(chip); 22 } 23 24 static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) 25 { 26 struct clps711x_chip *priv = to_clps711x_chip(chip); 27 unsigned int freq = clk_get_rate(priv->clk); 28 29 if (!freq) 30 return -EINVAL; 31 32 /* Store constant period value */ 33 pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq); 34 35 return 0; 36 } 37 38 static int clps711x_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, 39 const struct pwm_state *state) 40 { 41 struct clps711x_chip *priv = to_clps711x_chip(chip); 42 /* PWM0 - bits 4..7, PWM1 - bits 8..11 */ 43 u32 shift = (pwm->hwpwm + 1) * 4; 44 u32 pmpcon, val; 45 46 if (state->polarity != PWM_POLARITY_NORMAL) 47 return -EINVAL; 48 49 if (state->period != pwm->args.period) 50 return -EINVAL; 51 52 if (state->enabled) 53 val = mul_u64_u64_div_u64(state->duty_cycle, 0xf, state->period); 54 else 55 val = 0; 56 57 pmpcon = readl(priv->pmpcon); 58 pmpcon &= ~(0xf << shift); 59 pmpcon |= val << shift; 60 writel(pmpcon, priv->pmpcon); 61 62 return 0; 63 } 64 65 static const struct pwm_ops clps711x_pwm_ops = { 66 .request = clps711x_pwm_request, 67 .apply = clps711x_pwm_apply, 68 }; 69 70 static int clps711x_pwm_probe(struct platform_device *pdev) 71 { 72 struct pwm_chip *chip; 73 struct clps711x_chip *priv; 74 75 chip = devm_pwmchip_alloc(&pdev->dev, 2, sizeof(*priv)); 76 if (IS_ERR(chip)) 77 return PTR_ERR(chip); 78 priv = to_clps711x_chip(chip); 79 80 priv->pmpcon = devm_platform_ioremap_resource(pdev, 0); 81 if (IS_ERR(priv->pmpcon)) 82 return PTR_ERR(priv->pmpcon); 83 84 priv->clk = devm_clk_get(&pdev->dev, NULL); 85 if (IS_ERR(priv->clk)) 86 return PTR_ERR(priv->clk); 87 88 chip->ops = &clps711x_pwm_ops; 89 90 return devm_pwmchip_add(&pdev->dev, chip); 91 } 92 93 static const struct of_device_id clps711x_pwm_dt_ids[] = { 94 { .compatible = "cirrus,ep7209-pwm", }, 95 { } 96 }; 97 MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids); 98 99 static struct platform_driver clps711x_pwm_driver = { 100 .driver = { 101 .name = "clps711x-pwm", 102 .of_match_table = clps711x_pwm_dt_ids, 103 }, 104 .probe = clps711x_pwm_probe, 105 }; 106 module_platform_driver(clps711x_pwm_driver); 107 108 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); 109 MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver"); 110 MODULE_LICENSE("GPL"); 111