diff options
Diffstat (limited to 'drivers/misc/sim_detect.c')
-rw-r--r-- | drivers/misc/sim_detect.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/misc/sim_detect.c b/drivers/misc/sim_detect.c new file mode 100644 index 00000000000..213645ca46d --- /dev/null +++ b/drivers/misc/sim_detect.c @@ -0,0 +1,304 @@ +/* + * Copyright (C) ST-Ericsson SA 2011 + * + * Author: BIBEK BASU <bibek.basu@stericsson.com> + * + * License terms: GNU General Public License (GPL) version 2 + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/hrtimer.h> +#include <linux/workqueue.h> +#include <linux/uaccess.h> +#include <linux/modem/modem_client.h> +#include <mach/sim_detect.h> +#include <linux/regulator/consumer.h> + +/* time in millisec */ +#define TIMER_DELAY 10 + +struct sim_detect{ + struct work_struct timer_expired; + struct device *dev; + struct modem *modem; + struct hrtimer timer; + struct mutex lock; + int voltage; + struct regulator *vinvsim_regulator; + bool regulator_enabled; +}; + +static ssize_t show_voltage(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct sim_detect *data = dev_get_drvdata(dev); + int ret, len; + + ret = mutex_lock_interruptible(&data->lock); + if (ret < 0) + return ret; + + len = sprintf(buf, "%i\n", data->voltage); + + mutex_unlock(&data->lock); + + return len; +} + +static ssize_t write_voltage(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct sim_detect *sim_detect = dev_get_drvdata(dev); + long val; + int ret; + + /* check input */ + if (strict_strtol(buf, 0, &val) != 0) { + dev_err(dev, "Invalid voltage class configured.\n"); + return count; + } + + switch (val) { + case -1: + case 0: + case 1800000: + case 3000000: + break; + default: + dev_err(dev, "Invalid voltage class configured.\n"); + return count; + } + + /* lock */ + ret = mutex_lock_interruptible(&sim_detect->lock); + if (ret < 0) + return ret; + + /* update state */ + sim_detect->voltage = val; + + /* call regulator */ + switch (sim_detect->voltage) { + case 0: + /* SIM voltage is unknown, turn on regulator for 3 V SIM */ + case 3000000: + /* Vinvsim supply is used only for 3 V SIM */ + if (!sim_detect->regulator_enabled) { + ret = regulator_enable(sim_detect->vinvsim_regulator); + if (ret) { + dev_err(dev, "Failed to enable regulator.\n"); + goto out_unlock; + } + sim_detect->regulator_enabled = true; + } + break; + case 1800000: + case -1: + /* Vbatvsim is used otherwise */ + if (sim_detect->regulator_enabled) { + regulator_disable(sim_detect->vinvsim_regulator); + sim_detect->regulator_enabled = false; + } + } + +out_unlock: + /* unlock and return */ + mutex_unlock(&sim_detect->lock); + + return count; +} + +static DEVICE_ATTR(voltage, 0666, show_voltage, write_voltage); + +static struct attribute *sim_attributes[] = { + &dev_attr_voltage.attr, + NULL +}; + +static const struct attribute_group sim_attr_group = { + .attrs = sim_attributes, +}; + +static void inform_modem_release(struct work_struct *work) +{ + struct sim_detect *sim_detect = + container_of(work, struct sim_detect, timer_expired); + + /* call Modem Access Framework api to release modem */ + modem_release(sim_detect->modem); +} + +static enum hrtimer_restart timer_callback(struct hrtimer *timer) +{ + struct sim_detect *sim_detect = + container_of(timer, struct sim_detect, timer); + + schedule_work(&sim_detect->timer_expired); + return HRTIMER_NORESTART; +} + +static irqreturn_t sim_activity_irq(int irq, void *dev) +{ + struct sim_detect *sim_detect = dev; + + /* call Modem Access Framework api to acquire modem */ + modem_request(sim_detect->modem); + /* start the timer for 10ms */ + hrtimer_start(&sim_detect->timer, + ktime_set(0, TIMER_DELAY*NSEC_PER_MSEC), + HRTIMER_MODE_REL); + return IRQ_HANDLED; +} + +#ifdef CONFIG_PM +/** + * sim_detect_suspend() - This routine puts the Sim detect in to sustend state. + * @dev: pointer to device structure. + * + * This routine checks the current ongoing communication with Modem by + * examining the modem_get_usage and work_pending state. + * accordingly prevents suspend if modem communication + * is on-going. + */ +int sim_detect_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct sim_detect *sim_detect = platform_get_drvdata(pdev); + + dev_dbg(&pdev->dev, "%s called...\n", __func__); + /* if modem is accessed, event system suspend */ + if (modem_get_usage(sim_detect->modem) + || work_pending(&sim_detect->timer_expired)) + return -EBUSY; + else + return 0; +} + +static const struct dev_pm_ops sim_detect_dev_pm_ops = { + .suspend = sim_detect_suspend, +}; +#endif + + +static int __devinit sim_detect_probe(struct platform_device *pdev) +{ + struct sim_detect_platform_data *plat = dev_get_platdata(&pdev->dev); + struct sim_detect *sim_detect; + int ret; + + sim_detect = kzalloc(sizeof(struct sim_detect), GFP_KERNEL); + if (sim_detect == NULL) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + /* initialize data */ + mutex_init(&sim_detect->lock); + sim_detect->voltage = 0; + + sim_detect->dev = &pdev->dev; + INIT_WORK(&sim_detect->timer_expired, inform_modem_release); + hrtimer_init(&sim_detect->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + sim_detect->timer.function = timer_callback; + + sim_detect->modem = modem_get(sim_detect->dev, "u8500-shrm-modem"); + if (IS_ERR(sim_detect->modem)) { + ret = PTR_ERR(sim_detect->modem); + dev_err(sim_detect->dev, "Could not retrieve the modem\n"); + goto out_free; + } + + /* set drvdata */ + platform_set_drvdata(pdev, sim_detect); + + /* request irq */ + ret = request_threaded_irq(plat->irq_num, + NULL, sim_activity_irq, + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, + "sim activity", sim_detect); + if (ret < 0) + goto out_put_modem; + + /* get regulator */ + sim_detect->regulator_enabled = false; + sim_detect->vinvsim_regulator = regulator_get(sim_detect->dev, + "vinvsim"); + if (IS_ERR(sim_detect->vinvsim_regulator)) { + dev_err(&pdev->dev, + "Failed to get regulator. (dev_name %s).\n", + dev_name(sim_detect->dev)); + ret = PTR_ERR(sim_detect->vinvsim_regulator); + goto out_free_irq; + } + + /* register sysfs entry */ + ret = sysfs_create_group(&pdev->dev.kobj, &sim_attr_group); + if (ret != 0) { + dev_err(&pdev->dev, + "Failed to create attribute group: %d\n", ret); + goto out_free_regulator; + } + + return 0; + +out_free_regulator: + regulator_put(sim_detect->vinvsim_regulator); +out_free_irq: + free_irq(plat->irq_num, sim_detect); +out_put_modem: + modem_put(sim_detect->modem); + platform_set_drvdata(pdev, NULL); +out_free: + kfree(sim_detect); + return ret; +} + +static int __devexit sim_detect_remove(struct platform_device *pdev) +{ + struct sim_detect *sim_detect = platform_get_drvdata(pdev); + + sysfs_remove_group(&pdev->dev.kobj, &sim_attr_group); + regulator_put(sim_detect->vinvsim_regulator); + modem_put(sim_detect->modem); + platform_set_drvdata(pdev, NULL); + kfree(sim_detect); + return 0; +} + +static struct platform_driver sim_detect_driver = { + .driver = { + .name = "sim-detect", + .owner = THIS_MODULE, +#ifdef CONFIG_PM + .pm = &sim_detect_dev_pm_ops, +#endif + }, + .probe = sim_detect_probe, + .remove = __devexit_p(sim_detect_remove), +}; + +static int __init sim_detect_init(void) +{ + return platform_driver_register(&sim_detect_driver); +} +module_init(sim_detect_init); + +static void __exit sim_detect_exit(void) +{ + platform_driver_unregister(&sim_detect_driver); +} +module_exit(sim_detect_exit); + +MODULE_AUTHOR("BIBEK BASU <bibek.basu@stericsson.com>"); +MODULE_DESCRIPTION("Detects SIM Hot Swap and wakes modem"); +MODULE_ALIAS("platform:sim-detect"); +MODULE_LICENSE("GPL v2"); |