1 /* 2 * wm831x-on.c - WM831X ON pin driver 3 * 4 * Copyright (C) 2009 Wolfson Microelectronics plc 5 * 6 * This file is subject to the terms and conditions of the GNU General 7 * Public License. See the file "COPYING" in the main directory of this 8 * archive for more details. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/kernel.h> 23 #include <linux/errno.h> 24 #include <linux/input.h> 25 #include <linux/interrupt.h> 26 #include <linux/platform_device.h> 27 #include <linux/workqueue.h> 28 #include <linux/mfd/wm831x/core.h> 29 30 struct wm831x_on { 31 struct input_dev *dev; 32 struct delayed_work work; 33 struct wm831x *wm831x; 34 }; 35 36 /* 37 * The chip gives us an interrupt when the ON pin is asserted but we 38 * then need to poll to see when the pin is deasserted. 39 */ 40 static void wm831x_poll_on(struct work_struct *work) 41 { 42 struct wm831x_on *wm831x_on = container_of(work, struct wm831x_on, 43 work.work); 44 struct wm831x *wm831x = wm831x_on->wm831x; 45 int poll, ret; 46 47 ret = wm831x_reg_read(wm831x, WM831X_ON_PIN_CONTROL); 48 if (ret >= 0) { 49 poll = !(ret & WM831X_ON_PIN_STS); 50 51 input_report_key(wm831x_on->dev, KEY_POWER, poll); 52 input_sync(wm831x_on->dev); 53 } else { 54 dev_err(wm831x->dev, "Failed to read ON status: %d\n", ret); 55 poll = 1; 56 } 57 58 if (poll) 59 schedule_delayed_work(&wm831x_on->work, 100); 60 } 61 62 static irqreturn_t wm831x_on_irq(int irq, void *data) 63 { 64 struct wm831x_on *wm831x_on = data; 65 66 schedule_delayed_work(&wm831x_on->work, 0); 67 68 return IRQ_HANDLED; 69 } 70 71 static int wm831x_on_probe(struct platform_device *pdev) 72 { 73 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 74 struct wm831x_on *wm831x_on; 75 int irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0)); 76 int ret; 77 78 wm831x_on = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_on), 79 GFP_KERNEL); 80 if (!wm831x_on) { 81 dev_err(&pdev->dev, "Can't allocate data\n"); 82 return -ENOMEM; 83 } 84 85 wm831x_on->wm831x = wm831x; 86 INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on); 87 88 wm831x_on->dev = devm_input_allocate_device(&pdev->dev); 89 if (!wm831x_on->dev) { 90 dev_err(&pdev->dev, "Can't allocate input dev\n"); 91 ret = -ENOMEM; 92 goto err; 93 } 94 95 wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY); 96 wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER); 97 wm831x_on->dev->name = "wm831x_on"; 98 wm831x_on->dev->phys = "wm831x_on/input0"; 99 wm831x_on->dev->dev.parent = &pdev->dev; 100 101 ret = request_threaded_irq(irq, NULL, wm831x_on_irq, 102 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 103 "wm831x_on", 104 wm831x_on); 105 if (ret < 0) { 106 dev_err(&pdev->dev, "Unable to request IRQ: %d\n", ret); 107 goto err_input_dev; 108 } 109 ret = input_register_device(wm831x_on->dev); 110 if (ret) { 111 dev_dbg(&pdev->dev, "Can't register input device: %d\n", ret); 112 goto err_irq; 113 } 114 115 platform_set_drvdata(pdev, wm831x_on); 116 117 return 0; 118 119 err_irq: 120 free_irq(irq, wm831x_on); 121 err_input_dev: 122 err: 123 return ret; 124 } 125 126 static int wm831x_on_remove(struct platform_device *pdev) 127 { 128 struct wm831x_on *wm831x_on = platform_get_drvdata(pdev); 129 int irq = platform_get_irq(pdev, 0); 130 131 free_irq(irq, wm831x_on); 132 cancel_delayed_work_sync(&wm831x_on->work); 133 134 return 0; 135 } 136 137 static struct platform_driver wm831x_on_driver = { 138 .probe = wm831x_on_probe, 139 .remove = wm831x_on_remove, 140 .driver = { 141 .name = "wm831x-on", 142 }, 143 }; 144 module_platform_driver(wm831x_on_driver); 145 146 MODULE_ALIAS("platform:wm831x-on"); 147 MODULE_DESCRIPTION("WM831x ON pin"); 148 MODULE_LICENSE("GPL"); 149 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 150 151