1 /* 2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> 3 * PWM beeper driver 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License as published by the 7 * Free Software Foundation; either version 2 of the License, or (at your 8 * option) any later version. 9 * 10 * You should have received a copy of the GNU General Public License along 11 * with this program; if not, write to the Free Software Foundation, Inc., 12 * 675 Mass Ave, Cambridge, MA 02139, USA. 13 * 14 */ 15 16 #include <linux/input.h> 17 #include <linux/module.h> 18 #include <linux/kernel.h> 19 #include <linux/platform_device.h> 20 #include <linux/pwm.h> 21 #include <linux/slab.h> 22 23 struct pwm_beeper { 24 struct input_dev *input; 25 struct pwm_device *pwm; 26 unsigned long period; 27 }; 28 29 #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) 30 31 static int pwm_beeper_event(struct input_dev *input, 32 unsigned int type, unsigned int code, int value) 33 { 34 int ret = 0; 35 struct pwm_beeper *beeper = input_get_drvdata(input); 36 unsigned long period; 37 38 if (type != EV_SND || value < 0) 39 return -EINVAL; 40 41 switch (code) { 42 case SND_BELL: 43 value = value ? 1000 : 0; 44 break; 45 case SND_TONE: 46 break; 47 default: 48 return -EINVAL; 49 } 50 51 if (value == 0) { 52 pwm_config(beeper->pwm, 0, 0); 53 pwm_disable(beeper->pwm); 54 } else { 55 period = HZ_TO_NANOSECONDS(value); 56 ret = pwm_config(beeper->pwm, period / 2, period); 57 if (ret) 58 return ret; 59 ret = pwm_enable(beeper->pwm); 60 if (ret) 61 return ret; 62 beeper->period = period; 63 } 64 65 return 0; 66 } 67 68 static int __devinit pwm_beeper_probe(struct platform_device *pdev) 69 { 70 unsigned long pwm_id = (unsigned long)pdev->dev.platform_data; 71 struct pwm_beeper *beeper; 72 int error; 73 74 beeper = kzalloc(sizeof(*beeper), GFP_KERNEL); 75 if (!beeper) 76 return -ENOMEM; 77 78 beeper->pwm = pwm_request(pwm_id, "pwm beeper"); 79 80 if (IS_ERR(beeper->pwm)) { 81 error = PTR_ERR(beeper->pwm); 82 dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error); 83 goto err_free; 84 } 85 86 beeper->input = input_allocate_device(); 87 if (!beeper->input) { 88 dev_err(&pdev->dev, "Failed to allocate input device\n"); 89 error = -ENOMEM; 90 goto err_pwm_free; 91 } 92 beeper->input->dev.parent = &pdev->dev; 93 94 beeper->input->name = "pwm-beeper"; 95 beeper->input->phys = "pwm/input0"; 96 beeper->input->id.bustype = BUS_HOST; 97 beeper->input->id.vendor = 0x001f; 98 beeper->input->id.product = 0x0001; 99 beeper->input->id.version = 0x0100; 100 101 beeper->input->evbit[0] = BIT(EV_SND); 102 beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL); 103 104 beeper->input->event = pwm_beeper_event; 105 106 input_set_drvdata(beeper->input, beeper); 107 108 error = input_register_device(beeper->input); 109 if (error) { 110 dev_err(&pdev->dev, "Failed to register input device: %d\n", error); 111 goto err_input_free; 112 } 113 114 platform_set_drvdata(pdev, beeper); 115 116 return 0; 117 118 err_input_free: 119 input_free_device(beeper->input); 120 err_pwm_free: 121 pwm_free(beeper->pwm); 122 err_free: 123 kfree(beeper); 124 125 return error; 126 } 127 128 static int __devexit pwm_beeper_remove(struct platform_device *pdev) 129 { 130 struct pwm_beeper *beeper = platform_get_drvdata(pdev); 131 132 platform_set_drvdata(pdev, NULL); 133 input_unregister_device(beeper->input); 134 135 pwm_disable(beeper->pwm); 136 pwm_free(beeper->pwm); 137 138 kfree(beeper); 139 140 return 0; 141 } 142 143 #ifdef CONFIG_PM 144 static int pwm_beeper_suspend(struct device *dev) 145 { 146 struct pwm_beeper *beeper = dev_get_drvdata(dev); 147 148 if (beeper->period) 149 pwm_disable(beeper->pwm); 150 151 return 0; 152 } 153 154 static int pwm_beeper_resume(struct device *dev) 155 { 156 struct pwm_beeper *beeper = dev_get_drvdata(dev); 157 158 if (beeper->period) { 159 pwm_config(beeper->pwm, beeper->period / 2, beeper->period); 160 pwm_enable(beeper->pwm); 161 } 162 163 return 0; 164 } 165 166 static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops, 167 pwm_beeper_suspend, pwm_beeper_resume); 168 169 #define PWM_BEEPER_PM_OPS (&pwm_beeper_pm_ops) 170 #else 171 #define PWM_BEEPER_PM_OPS NULL 172 #endif 173 174 static struct platform_driver pwm_beeper_driver = { 175 .probe = pwm_beeper_probe, 176 .remove = __devexit_p(pwm_beeper_remove), 177 .driver = { 178 .name = "pwm-beeper", 179 .owner = THIS_MODULE, 180 .pm = PWM_BEEPER_PM_OPS, 181 }, 182 }; 183 184 static int __init pwm_beeper_init(void) 185 { 186 return platform_driver_register(&pwm_beeper_driver); 187 } 188 module_init(pwm_beeper_init); 189 190 static void __exit pwm_beeper_exit(void) 191 { 192 platform_driver_unregister(&pwm_beeper_driver); 193 } 194 module_exit(pwm_beeper_exit); 195 196 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 197 MODULE_DESCRIPTION("PWM beeper driver"); 198 MODULE_LICENSE("GPL"); 199 MODULE_ALIAS("platform:pwm-beeper"); 200