Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/drivers/platform/x86/intel_mid_powerbtn.c

  1 /*
  2  * Power button driver for Medfield.
  3  *
  4  * Copyright (C) 2010 Intel Corp
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License as published by
  8  * the Free Software Foundation; version 2 of the License.
  9  *
 10  * This program is distributed in the hope that it will be useful, but
 11  * WITHOUT ANY WARRANTY; without even the implied warranty of
 12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 13  * General Public License for more details.
 14  *
 15  * You should have received a copy of the GNU General Public License along
 16  * with this program; if not, write to the Free Software Foundation, Inc.,
 17  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 18  */
 19 
 20 #include <linux/module.h>
 21 #include <linux/init.h>
 22 #include <linux/interrupt.h>
 23 #include <linux/slab.h>
 24 #include <linux/platform_device.h>
 25 #include <linux/input.h>
 26 #include <linux/mfd/intel_msic.h>
 27 #include <linux/pm_wakeirq.h>
 28 
 29 #define DRIVER_NAME "msic_power_btn"
 30 
 31 #define MSIC_PB_LEVEL   (1 << 3) /* 1 - release, 0 - press */
 32 
 33 /*
 34  * MSIC document ti_datasheet defines the 1st bit reg 0x21 is used to mask
 35  * power button interrupt
 36  */
 37 #define MSIC_PWRBTNM    (1 << 0)
 38 
 39 static irqreturn_t mfld_pb_isr(int irq, void *dev_id)
 40 {
 41         struct input_dev *input = dev_id;
 42         int ret;
 43         u8 pbstat;
 44 
 45         ret = intel_msic_reg_read(INTEL_MSIC_PBSTATUS, &pbstat);
 46         dev_dbg(input->dev.parent, "PB_INT status= %d\n", pbstat);
 47 
 48         if (ret < 0) {
 49                 dev_err(input->dev.parent, "Read error %d while reading"
 50                                " MSIC_PB_STATUS\n", ret);
 51         } else {
 52                 input_event(input, EV_KEY, KEY_POWER,
 53                                !(pbstat & MSIC_PB_LEVEL));
 54                 input_sync(input);
 55         }
 56 
 57         return IRQ_HANDLED;
 58 }
 59 
 60 static int mfld_pb_probe(struct platform_device *pdev)
 61 {
 62         struct input_dev *input;
 63         int irq = platform_get_irq(pdev, 0);
 64         int error;
 65 
 66         if (irq < 0)
 67                 return -EINVAL;
 68 
 69         input = input_allocate_device();
 70         if (!input)
 71                 return -ENOMEM;
 72 
 73         input->name = pdev->name;
 74         input->phys = "power-button/input0";
 75         input->id.bustype = BUS_HOST;
 76         input->dev.parent = &pdev->dev;
 77 
 78         input_set_capability(input, EV_KEY, KEY_POWER);
 79 
 80         error = request_threaded_irq(irq, NULL, mfld_pb_isr, 0,
 81                                      DRIVER_NAME, input);
 82         if (error) {
 83                 dev_err(&pdev->dev, "Unable to request irq %d for mfld power"
 84                                 "button\n", irq);
 85                 goto err_free_input;
 86         }
 87 
 88         device_init_wakeup(&pdev->dev, true);
 89         dev_pm_set_wake_irq(&pdev->dev, irq);
 90 
 91         error = input_register_device(input);
 92         if (error) {
 93                 dev_err(&pdev->dev, "Unable to register input dev, error "
 94                                 "%d\n", error);
 95                 goto err_free_irq;
 96         }
 97 
 98         platform_set_drvdata(pdev, input);
 99 
100         /*
101          * SCU firmware might send power button interrupts to IA core before
102          * kernel boots and doesn't get EOI from IA core. The first bit of
103          * MSIC reg 0x21 is kept masked, and SCU firmware doesn't send new
104          * power interrupt to Android kernel. Unmask the bit when probing
105          * power button in kernel.
106          * There is a very narrow race between irq handler and power button
107          * initialization. The race happens rarely. So we needn't worry
108          * about it.
109          */
110         error = intel_msic_reg_update(INTEL_MSIC_IRQLVL1MSK, 0, MSIC_PWRBTNM);
111         if (error) {
112                 dev_err(&pdev->dev, "Unable to clear power button interrupt, "
113                                 "error: %d\n", error);
114                 goto err_free_irq;
115         }
116 
117         return 0;
118 
119 err_free_irq:
120         free_irq(irq, input);
121 err_free_input:
122         input_free_device(input);
123         return error;
124 }
125 
126 static int mfld_pb_remove(struct platform_device *pdev)
127 {
128         struct input_dev *input = platform_get_drvdata(pdev);
129         int irq = platform_get_irq(pdev, 0);
130 
131         dev_pm_clear_wake_irq(&pdev->dev);
132         device_init_wakeup(&pdev->dev, false);
133         free_irq(irq, input);
134         input_unregister_device(input);
135 
136         return 0;
137 }
138 
139 static struct platform_driver mfld_pb_driver = {
140         .driver = {
141                 .name = DRIVER_NAME,
142         },
143         .probe  = mfld_pb_probe,
144         .remove = mfld_pb_remove,
145 };
146 
147 module_platform_driver(mfld_pb_driver);
148 
149 MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>");
150 MODULE_DESCRIPTION("Intel Medfield Power Button Driver");
151 MODULE_LICENSE("GPL v2");
152 MODULE_ALIAS("platform:" DRIVER_NAME);
153 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us