diff options
Diffstat (limited to 'drivers/platform/x86/intel_mid_powerbtn.c')
| -rw-r--r-- | drivers/platform/x86/intel_mid_powerbtn.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_mid_powerbtn.c b/drivers/platform/x86/intel_mid_powerbtn.c new file mode 100644 index 000000000..22606d6b2 --- /dev/null +++ b/drivers/platform/x86/intel_mid_powerbtn.c @@ -0,0 +1,146 @@ +/* + * 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 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) + 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 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); + + return 0; +} + +static struct platform_driver mfld_pb_driver = { + .driver = { + .name = DRIVER_NAME, + }, + .probe = mfld_pb_probe, + .remove = 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); |