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_config(beeper->pwm, 0, 0); 54 pwm_disable(beeper->pwm); 55 } else { 56 period = HZ_TO_NANOSECONDS(value); 57 ret = pwm_config(beeper->pwm, period / 2, period); 58 if (ret) 59 return ret; 60 ret = pwm_enable(beeper->pwm); 61 if (ret) 62 return ret; 63 beeper->period = period; 64 } 65 66 return 0; 67 } 68 69 static int pwm_beeper_probe(struct platform_device *pdev) 70 { 71 unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev); 72 struct pwm_beeper *beeper; 73 int error; 74 75 beeper = kzalloc(sizeof(*beeper), GFP_KERNEL); 76 if (!beeper) 77 return -ENOMEM; 78 79 beeper->pwm = pwm_get(&pdev->dev, NULL); 80 if (IS_ERR(beeper->pwm)) { 81 dev_dbg(&pdev->dev, "unable to request PWM, trying legacy API\n"); 82 beeper->pwm = pwm_request(pwm_id, "pwm beeper"); 83 } 84 85 if (IS_ERR(beeper->pwm)) { 86 error = PTR_ERR(beeper->pwm); 87 dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error); 88 goto err_free; 89 } 90 91 beeper->input = input_allocate_device(); 92 if (!beeper->input) { 93 dev_err(&pdev->dev, "Failed to allocate input device\n"); 94 error = -ENOMEM; 95 goto err_pwm_free; 96 } 97 beeper->input->dev.parent = &pdev->dev; 98 99 beeper->input->name = "pwm-beeper"; 100 beeper->input->phys = "pwm/input0"; 101 beeper->input->id.bustype = BUS_HOST; 102 beeper->input->id.vendor = 0x001f; 103 beeper->input->id.product = 0x0001; 104 beeper->input->id.version = 0x0100; 105 106 beeper->input->evbit[0] = BIT(EV_SND); 107 beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL); 108 109 beeper->input->event = pwm_beeper_event; 110 111 input_set_drvdata(beeper->input, beeper); 112 113 error = input_register_device(beeper->input); 114 if (error) { 115 dev_err(&pdev->dev, "Failed to register input device: %d\n", error); 116 goto err_input_free; 117 } 118 119 platform_set_drvdata(pdev, beeper); 120 121 return 0; 122 123 err_input_free: 124 input_free_device(beeper->input); 125 err_pwm_free: 126 pwm_free(beeper->pwm); 127 err_free: 128 kfree(beeper); 129 130 return error; 131 } 132 133 static int pwm_beeper_remove(struct platform_device *pdev) 134 { 135 struct pwm_beeper *beeper = platform_get_drvdata(pdev); 136 137 input_unregister_device(beeper->input); 138 139 pwm_disable(beeper->pwm); 140 pwm_free(beeper->pwm); 141 142 kfree(beeper); 143 144 return 0; 145 } 146 147 static int __maybe_unused pwm_beeper_suspend(struct device *dev) 148 { 149 struct pwm_beeper *beeper = dev_get_drvdata(dev); 150 151 if (beeper->period) 152 pwm_disable(beeper->pwm); 153 154 return 0; 155 } 156 157 static int __maybe_unused pwm_beeper_resume(struct device *dev) 158 { 159 struct pwm_beeper *beeper = dev_get_drvdata(dev); 160 161 if (beeper->period) { 162 pwm_config(beeper->pwm, beeper->period / 2, beeper->period); 163 pwm_enable(beeper->pwm); 164 } 165 166 return 0; 167 } 168 169 static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops, 170 pwm_beeper_suspend, pwm_beeper_resume); 171 172 #ifdef CONFIG_PM_SLEEP 173 #define PWM_BEEPER_PM_OPS (&pwm_beeper_pm_ops) 174 #else 175 #define PWM_BEEPER_PM_OPS NULL 176 #endif 177 178 #ifdef CONFIG_OF 179 static const struct of_device_id pwm_beeper_match[] = { 180 { .compatible = "pwm-beeper", }, 181 { }, 182 }; 183 #endif 184 185 static struct platform_driver pwm_beeper_driver = { 186 .probe = pwm_beeper_probe, 187 .remove = pwm_beeper_remove, 188 .driver = { 189 .name = "pwm-beeper", 190 .pm = PWM_BEEPER_PM_OPS, 191 .of_match_table = of_match_ptr(pwm_beeper_match), 192 }, 193 }; 194 module_platform_driver(pwm_beeper_driver); 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