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