1 /* 2 * Copyright (C) ST-Ericsson SA 2010 3 * 4 * Author: Arun R Murthy <arun.murthy@stericsson.com> 5 * License terms: GNU General Public License (GPL) version 2 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 }; 26 27 static int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 28 int duty_ns, int period_ns) 29 { 30 int ret = 0; 31 unsigned int higher_val, lower_val; 32 u8 reg; 33 34 /* 35 * get the first 8 bits that are be written to 36 * AB8500_PWM_OUT_CTRL1_REG[0:7] 37 */ 38 lower_val = duty_ns & 0x00FF; 39 /* 40 * get bits [9:10] that are to be written to 41 * AB8500_PWM_OUT_CTRL2_REG[0:1] 42 */ 43 higher_val = ((duty_ns & 0x0300) >> 8); 44 45 reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2); 46 47 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, 48 reg, (u8)lower_val); 49 if (ret < 0) 50 return ret; 51 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, 52 (reg + 1), (u8)higher_val); 53 54 return ret; 55 } 56 57 static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) 58 { 59 int ret; 60 61 ret = abx500_mask_and_set_register_interruptible(chip->dev, 62 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 63 1 << (chip->base - 1), 1 << (chip->base - 1)); 64 if (ret < 0) 65 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n", 66 pwm->label, ret); 67 return ret; 68 } 69 70 static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) 71 { 72 int ret; 73 74 ret = abx500_mask_and_set_register_interruptible(chip->dev, 75 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 76 1 << (chip->base - 1), 0); 77 if (ret < 0) 78 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", 79 pwm->label, ret); 80 } 81 82 static const struct pwm_ops ab8500_pwm_ops = { 83 .config = ab8500_pwm_config, 84 .enable = ab8500_pwm_enable, 85 .disable = ab8500_pwm_disable, 86 .owner = THIS_MODULE, 87 }; 88 89 static int ab8500_pwm_probe(struct platform_device *pdev) 90 { 91 struct ab8500_pwm_chip *ab8500; 92 int err; 93 94 /* 95 * Nothing to be done in probe, this is required to get the 96 * device which is required for ab8500 read and write 97 */ 98 ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL); 99 if (ab8500 == NULL) 100 return -ENOMEM; 101 102 ab8500->chip.dev = &pdev->dev; 103 ab8500->chip.ops = &ab8500_pwm_ops; 104 ab8500->chip.base = pdev->id; 105 ab8500->chip.npwm = 1; 106 107 err = pwmchip_add(&ab8500->chip); 108 if (err < 0) 109 return err; 110 111 dev_dbg(&pdev->dev, "pwm probe successful\n"); 112 platform_set_drvdata(pdev, ab8500); 113 114 return 0; 115 } 116 117 static int ab8500_pwm_remove(struct platform_device *pdev) 118 { 119 struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev); 120 int err; 121 122 err = pwmchip_remove(&ab8500->chip); 123 if (err < 0) 124 return err; 125 126 dev_dbg(&pdev->dev, "pwm driver removed\n"); 127 128 return 0; 129 } 130 131 static struct platform_driver ab8500_pwm_driver = { 132 .driver = { 133 .name = "ab8500-pwm", 134 }, 135 .probe = ab8500_pwm_probe, 136 .remove = ab8500_pwm_remove, 137 }; 138 module_platform_driver(ab8500_pwm_driver); 139 140 MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); 141 MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); 142 MODULE_ALIAS("platform:ab8500-pwm"); 143 MODULE_LICENSE("GPL v2"); 144