U8500 : driver for awaking modem on sim hot swap activity

This driver uses GPIO to detect SIM hot swap and uses
Modem Access Framework to wake up modem.

ST-Ericsson Linux next: 336280
ST-Ericsson ID: 329459
ST-Ericsson FOSS-OUT ID: Trivial

Change-Id: Ib4b1f67422317850f5d859ddf4c5e457f4cb616c
Signed-off-by: Bibek Basu <bibek.basu@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/23543
Reviewed-by: QATEST
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>

3 files changed, 173 insertions, 0 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index c0632e8e2aa..d687a4228c0 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -519,6 +519,15 @@ config U5500_MBOX
 	help
 	  Add support for U5500 mailbox communication with modem side
 
+config U8500_SIM_DETECT
+	bool "Sim hot swap detection support"
+	depends on (MODEM && UX500_SOC_DB8500)
+	default y
+	help
+	  Add support for sim hot swap detection support in U8500.Driver
+	  basically wakes up the modem if its sleeping when sim hot plug
+	  in/out has happened.
+
 source "drivers/misc/Kconfig.stm"
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 901a16a343a..7670e60f816 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -53,3 +53,4 @@ obj-$(CONFIG_STM_I2S)           += i2s/
 obj-$(CONFIG_STE_AUDIO_IO_DEV)	+= audio_io_dev/
 obj-$(CONFIG_HWMEM)             += hwmem/
 obj-$(CONFIG_U5500_MBOX)	+= mbox.o mbox_channels-db5500.o
+obj-$(CONFIG_U8500_SIM_DETECT)	+= sim_detect.o
diff --git a/drivers/misc/sim_detect.c b/drivers/misc/sim_detect.c
new file mode 100644
index 00000000000..24862edfca7
--- /dev/null
+++ b/drivers/misc/sim_detect.c
@@ -0,0 +1,163 @@
+/*
+ * 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/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/modem/modem_client.h>
+#include <mach/sim_detect.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;
+};
+
+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;
+	}
+	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;
+	}
+	platform_set_drvdata(pdev, sim_detect);
+	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_free_irq;
+out_free_irq:
+	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);
+
+	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("SIM DETECT INTERRUPT driver");
+MODULE_LICENSE("GPL v2");