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/of.h> 20 #include <linux/platform_device.h> 21 #include <linux/pwm.h> 22 #include <linux/slab.h> 23 24 struct pwm_beeper { 25 struct input_dev *input; 26 struct pwm_device *pwm; 27 unsigned long period; 28 }; 29 30 #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) 31 32 static int pwm_beeper_event(struct input_dev *input, 33 unsigned int type, unsigned int code, int value) 34 { 35 int ret = 0; 36 struct pwm_beeper *beeper = input_get_drvdata(input); 37 unsigned long period; 38 39 if (type != EV_SND || value < 0) 40 return -EINVAL; 41 42 switch (code) { 43 case SND_BELL: 44 value = value ? 1000 : 0; 45 break; 46 case SND_TONE: 47 break; 48 default: 49 return -EINVAL; 50 } 51 52 if (value == 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 pwm_beeper_probe(struct platform_device *pdev) 69 { 70 unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev); 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_get(&pdev->dev, NULL); 79 if (IS_ERR(beeper->pwm)) { 80 dev_dbg(&pdev->dev, "unable to request PWM, trying legacy API\n"); 81 beeper->pwm = pwm_request(pwm_id, "pwm beeper"); 82 } 83 84 if (IS_ERR(beeper->pwm)) { 85 error = PTR_ERR(beeper->pwm); 86 dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error); 87 goto err_free; 88 } 89 90 beeper->input = input_allocate_device(); 91 if (!beeper->input) { 92 dev_err(&pdev->dev, "Failed to allocate input device\n"); 93 error = -ENOMEM; 94 goto err_pwm_free; 95 } 96 beeper->input->dev.parent = &pdev->dev; 97 98 beeper->input->name = "pwm-beeper"; 99 beeper->input->phys = "pwm/input0"; 100 beeper->input->id.bustype = BUS_HOST; 101 beeper->input->id.vendor = 0x001f; 102 beeper->input->id.product = 0x0001; 103 beeper->input->id.version = 0x0100; 104 105 beeper->input->evbit[0] = BIT(EV_SND); 106 beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL); 107 108 beeper->input->event = pwm_beeper_event; 109 110 input_set_drvdata(beeper->input, beeper); 111 112 error = input_register_device(beeper->input); 113 if (error) { 114 dev_err(&pdev->dev, "Failed to register input device: %d\n", error); 115 goto err_input_free; 116 } 117 118 platform_set_drvdata(pdev, beeper); 119 120 return 0; 121 122 err_input_free: 123 input_free_device(beeper->input); 124 err_pwm_free: 125 pwm_free(beeper->pwm); 126 err_free: 127 kfree(beeper); 128 129 return error; 130 } 131 132 static int pwm_beeper_remove(struct platform_device *pdev) 133 { 134 struct pwm_beeper *beeper = platform_get_drvdata(pdev); 135 136 input_unregister_device(beeper->input); 137 138 pwm_disable(beeper->pwm); 139 pwm_free(beeper->pwm); 140 141 kfree(beeper); 142 143 return 0; 144 } 145 146 static int __maybe_unused pwm_beeper_suspend(struct device *dev) 147 { 148 struct pwm_beeper *beeper = dev_get_drvdata(dev); 149 150 if (beeper->period) 151 pwm_disable(beeper->pwm); 152 153 return 0; 154 } 155 156 static int __maybe_unused pwm_beeper_resume(struct device *dev) 157 { 158 struct pwm_beeper *beeper = dev_get_drvdata(dev); 159 160 if (beeper->period) { 161 pwm_config(beeper->pwm, beeper->period / 2, beeper->period); 162 pwm_enable(beeper->pwm); 163 } 164 165 return 0; 166 } 167 168 static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops, 169 pwm_beeper_suspend, pwm_beeper_resume); 170 171 #ifdef CONFIG_OF 172 static const struct of_device_id pwm_beeper_match[] = { 173 { .compatible = "pwm-beeper", }, 174 { }, 175 }; 176 MODULE_DEVICE_TABLE(of, pwm_beeper_match); 177 #endif 178 179 static struct platform_driver pwm_beeper_driver = { 180 .probe = pwm_beeper_probe, 181 .remove = pwm_beeper_remove, 182 .driver = { 183 .name = "pwm-beeper", 184 .pm = &pwm_beeper_pm_ops, 185 .of_match_table = of_match_ptr(pwm_beeper_match), 186 }, 187 }; 188 module_platform_driver(pwm_beeper_driver); 189 190 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 191 MODULE_DESCRIPTION("PWM beeper driver"); 192 MODULE_LICENSE("GPL"); 193 MODULE_ALIAS("platform:pwm-beeper"); 194