| /* |
| * Power button driver for Medfield. |
| * |
| * Copyright (C) 2010 Intel Corp |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/slab.h> |
| #include <linux/platform_device.h> |
| #include <linux/input.h> |
| #include <linux/mfd/intel_msic.h> |
| |
| #define DRIVER_NAME "msic_power_btn" |
| |
| #define MSIC_PB_LEVEL (1 << 3) /* 1 - release, 0 - press */ |
| |
| /* |
| * MSIC document ti_datasheet defines the 1st bit reg 0x21 is used to mask |
| * power button interrupt |
| */ |
| #define MSIC_PWRBTNM (1 << 0) |
| |
| static irqreturn_t mfld_pb_isr(int irq, void *dev_id) |
| { |
| struct input_dev *input = dev_id; |
| int ret; |
| u8 pbstat; |
| |
| ret = intel_msic_reg_read(INTEL_MSIC_PBSTATUS, &pbstat); |
| dev_dbg(input->dev.parent, "PB_INT status= %d\n", pbstat); |
| |
| if (ret < 0) { |
| dev_err(input->dev.parent, "Read error %d while reading" |
| " MSIC_PB_STATUS\n", ret); |
| } else { |
| input_event(input, EV_KEY, KEY_POWER, |
| !(pbstat & MSIC_PB_LEVEL)); |
| input_sync(input); |
| } |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int __devinit mfld_pb_probe(struct platform_device *pdev) |
| { |
| struct input_dev *input; |
| int irq = platform_get_irq(pdev, 0); |
| int error; |
| |
| if (irq < 0) |
| return -EINVAL; |
| |
| input = input_allocate_device(); |
| if (!input) { |
| dev_err(&pdev->dev, "Input device allocation error\n"); |
| return -ENOMEM; |
| } |
| |
| input->name = pdev->name; |
| input->phys = "power-button/input0"; |
| input->id.bustype = BUS_HOST; |
| input->dev.parent = &pdev->dev; |
| |
| input_set_capability(input, EV_KEY, KEY_POWER); |
| |
| error = request_threaded_irq(irq, NULL, mfld_pb_isr, IRQF_NO_SUSPEND, |
| DRIVER_NAME, input); |
| if (error) { |
| dev_err(&pdev->dev, "Unable to request irq %d for mfld power" |
| "button\n", irq); |
| goto err_free_input; |
| } |
| |
| error = input_register_device(input); |
| if (error) { |
| dev_err(&pdev->dev, "Unable to register input dev, error " |
| "%d\n", error); |
| goto err_free_irq; |
| } |
| |
| platform_set_drvdata(pdev, input); |
| |
| /* |
| * SCU firmware might send power button interrupts to IA core before |
| * kernel boots and doesn't get EOI from IA core. The first bit of |
| * MSIC reg 0x21 is kept masked, and SCU firmware doesn't send new |
| * power interrupt to Android kernel. Unmask the bit when probing |
| * power button in kernel. |
| * There is a very narrow race between irq handler and power button |
| * initialization. The race happens rarely. So we needn't worry |
| * about it. |
| */ |
| error = intel_msic_reg_update(INTEL_MSIC_IRQLVL1MSK, 0, MSIC_PWRBTNM); |
| if (error) { |
| dev_err(&pdev->dev, "Unable to clear power button interrupt, " |
| "error: %d\n", error); |
| goto err_free_irq; |
| } |
| |
| return 0; |
| |
| err_free_irq: |
| free_irq(irq, input); |
| err_free_input: |
| input_free_device(input); |
| return error; |
| } |
| |
| static int __devexit mfld_pb_remove(struct platform_device *pdev) |
| { |
| struct input_dev *input = platform_get_drvdata(pdev); |
| int irq = platform_get_irq(pdev, 0); |
| |
| free_irq(irq, input); |
| input_unregister_device(input); |
| platform_set_drvdata(pdev, NULL); |
| |
| return 0; |
| } |
| |
| static struct platform_driver mfld_pb_driver = { |
| .driver = { |
| .name = DRIVER_NAME, |
| .owner = THIS_MODULE, |
| }, |
| .probe = mfld_pb_probe, |
| .remove = __devexit_p(mfld_pb_remove), |
| }; |
| |
| module_platform_driver(mfld_pb_driver); |
| |
| MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>"); |
| MODULE_DESCRIPTION("Intel Medfield Power Button Driver"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS("platform:" DRIVER_NAME); |