1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) ST-Ericsson SA 2010 4 * 5 * Author: Arun R Murthy <arun.murthy@stericsson.com> 6 */ 7 #include <linux/err.h> 8 #include <linux/platform_device.h> 9 #include <linux/slab.h> 10 #include <linux/pwm.h> 11 #include <linux/mfd/abx500.h> 12 #include <linux/mfd/abx500/ab8500.h> 13 #include <linux/module.h> 14 15 /* 16 * PWM Out generators 17 * Bank: 0x10 18 */ 19 #define AB8500_PWM_OUT_CTRL1_REG 0x60 20 #define AB8500_PWM_OUT_CTRL2_REG 0x61 21 #define AB8500_PWM_OUT_CTRL7_REG 0x66 22 23 struct ab8500_pwm_chip { 24 struct pwm_chip chip; 25 unsigned int hwid; 26 }; 27 28 static struct ab8500_pwm_chip *ab8500_pwm_from_chip(struct pwm_chip *chip) 29 { 30 return container_of(chip, struct ab8500_pwm_chip, chip); 31 } 32 33 static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, 34 const struct pwm_state *state) 35 { 36 int ret; 37 u8 reg; 38 unsigned int higher_val, lower_val; 39 struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip); 40 41 if (state->polarity != PWM_POLARITY_NORMAL) 42 return -EINVAL; 43 44 if (!state->enabled) { 45 ret = abx500_mask_and_set_register_interruptible(chip->dev, 46 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 47 1 << ab8500->hwid, 0); 48 49 if (ret < 0) 50 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", 51 pwm->label, ret); 52 return ret; 53 } 54 55 /* 56 * get the first 8 bits that are be written to 57 * AB8500_PWM_OUT_CTRL1_REG[0:7] 58 */ 59 lower_val = state->duty_cycle & 0x00FF; 60 /* 61 * get bits [9:10] that are to be written to 62 * AB8500_PWM_OUT_CTRL2_REG[0:1] 63 */ 64 higher_val = ((state->duty_cycle & 0x0300) >> 8); 65 66 reg = AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2); 67 68 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, 69 reg, (u8)lower_val); 70 if (ret < 0) 71 return ret; 72 73 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, 74 (reg + 1), (u8)higher_val); 75 if (ret < 0) 76 return ret; 77 78 ret = abx500_mask_and_set_register_interruptible(chip->dev, 79 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 80 1 << ab8500->hwid, 1 << ab8500->hwid); 81 if (ret < 0) 82 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n", 83 pwm->label, ret); 84 85 return ret; 86 } 87 88 static const struct pwm_ops ab8500_pwm_ops = { 89 .apply = ab8500_pwm_apply, 90 .owner = THIS_MODULE, 91 }; 92 93 static int ab8500_pwm_probe(struct platform_device *pdev) 94 { 95 struct ab8500_pwm_chip *ab8500; 96 int err; 97 98 if (pdev->id < 1 || pdev->id > 31) 99 return dev_err_probe(&pdev->dev, EINVAL, "Invalid device id %d\n", pdev->id); 100 101 /* 102 * Nothing to be done in probe, this is required to get the 103 * device which is required for ab8500 read and write 104 */ 105 ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL); 106 if (ab8500 == NULL) 107 return -ENOMEM; 108 109 ab8500->chip.dev = &pdev->dev; 110 ab8500->chip.ops = &ab8500_pwm_ops; 111 ab8500->chip.npwm = 1; 112 ab8500->hwid = pdev->id - 1; 113 114 err = devm_pwmchip_add(&pdev->dev, &ab8500->chip); 115 if (err < 0) 116 return dev_err_probe(&pdev->dev, err, "Failed to add pwm chip\n"); 117 118 dev_dbg(&pdev->dev, "pwm probe successful\n"); 119 120 return 0; 121 } 122 123 static struct platform_driver ab8500_pwm_driver = { 124 .driver = { 125 .name = "ab8500-pwm", 126 }, 127 .probe = ab8500_pwm_probe, 128 }; 129 module_platform_driver(ab8500_pwm_driver); 130 131 MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); 132 MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); 133 MODULE_ALIAS("platform:ab8500-pwm"); 134 MODULE_LICENSE("GPL v2"); 135