1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/mfd/m4sensorhub-panic.c b/drivers/mfd/m4sensorhub-panic.c
new file mode 100644
index 00000000000..aaf35f89886
--- /dev/null
+++ b/drivers/mfd/m4sensorhub-panic.c
@@ -0,0 +1,248 @@
+/*
+ * Copyright (C) 2012 Motorola, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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/mutex.h>
+#include <linux/delay.h>
+#include <linux/m4sensorhub.h>
+#include <linux/slab.h>
+
+
+
+/* --------------- Global Declarations -------------- */
+#define PANIC_BANK              0xFF /* Reserved for Panic bank */
+#define PANIC_CMD_CHECK         0xCD /* Panic Handoff command */
+#define PANIC_RESP_CHECK        0xDeadBeef /* Panic Handoff Magic code */
+
+/* ------------ Local Function Prototypes ----------- */
+
+/* --------------- Local Declarations -------------- */
+static const char *callback_name[PANICHDL_MAX] = {
+	[PANICHDL_IRQ_RESTORE] = "irq_restore",
+};
+
+struct m4sensorhub_panic_callback {
+	void (*callback)(struct m4sensorhub_data *, void *);
+	void *data;
+};
+
+struct m4sensorhub_panicdata {
+	struct mutex lock;  /* lock callback and data */
+	struct m4sensorhub_panic_callback funcs[PANICHDL_MAX];
+};
+
+union panic_buf {
+	struct _in {
+		unsigned char bank;
+		unsigned char cmd;
+	} in;
+	unsigned int data;
+};
+
+/* -------------- Local Data Structures ------------- */
+
+/* -------------- Global Functions ----------------- */
+
+/* m4sensorhub_panic_init()
+
+   Initialized panic private data structures.
+
+   Returns 0 on success or negative error code on failure
+
+     m4sensorhub - pointer to the main m4sensorhub data struct
+*/
+int m4sensorhub_panic_init(struct m4sensorhub_data *m4sensorhub)
+{
+	int retval = 0;
+	struct m4sensorhub_panicdata *data;
+
+	data = kzalloc(sizeof(struct m4sensorhub_panicdata), GFP_KERNEL);
+	if (data) {
+		mutex_init(&data->lock);
+		m4sensorhub->panicdata = data;
+	} else {
+		KDEBUG(M4SH_ERROR, "m4sensorhub: Memory error in panic_init\n");
+		retval = -ENOMEM;
+	}
+	return retval;
+}
+EXPORT_SYMBOL_GPL(m4sensorhub_panic_init);
+
+/* m4sensorhub_panic_shutdown()
+
+   Shutdown the M4 sensor hub Panic subsystem
+
+     m4sensorhub - pointer to the main m4sensorhub data struct
+*/
+void m4sensorhub_panic_shutdown(struct m4sensorhub_data *m4sensorhub)
+{
+	if (m4sensorhub && m4sensorhub->panicdata) {
+		struct m4sensorhub_panicdata *data = m4sensorhub->panicdata;
+		m4sensorhub->panicdata = NULL;
+		if (mutex_is_locked(&data->lock))
+			mutex_unlock(&data->lock);
+		mutex_destroy(&data->lock);
+		kfree(data);
+	}
+}
+EXPORT_SYMBOL_GPL(m4sensorhub_panic_shutdown);
+
+/* m4sensorhub_panic_register()
+
+   Register an panic handler to monitor M4 panic reset
+
+   Returns 0 on success or negative error code on failure
+
+     m4sensorhub - pointer to the main m4sensorhub data struct
+     index - M4 Sensor Hub panic handler to resiter for
+     cb_func - panic handler function to execute after M4 reset
+     data - pointer to data for panic handler function
+*/
+
+int m4sensorhub_panic_register(struct m4sensorhub_data *m4sensorhub,
+	enum m4sensorhub_panichdl_index index,
+	void (*cb_func) (struct m4sensorhub_data *, void *),
+	void *data)
+{
+	struct m4sensorhub_panicdata *panicdata;
+	int retval = 0;
+
+	if (!m4sensorhub || (index >= PANICHDL_MAX) || !cb_func)
+		return -EINVAL;
+
+	panicdata = (struct m4sensorhub_panicdata *)m4sensorhub->panicdata;
+	mutex_lock(&panicdata->lock);
+	if (panicdata->funcs[index].callback == NULL) {
+		panicdata->funcs[index].callback = cb_func;
+		panicdata->funcs[index].data = data;
+		KDEBUG(M4SH_NOTICE, "m4sensorhub: %s callback registered\n",
+			callback_name[index]);
+	} else {
+		KDEBUG(M4SH_ERROR, "m4sensorhub: %s callback"\
+			" registration failed\n", callback_name[index]);
+		retval = -EPERM;
+	}
+	mutex_unlock(&panicdata->lock);
+
+	return retval;
+}
+EXPORT_SYMBOL_GPL(m4sensorhub_panic_register);
+
+/* m4sensorhub_panic_unregister()
+
+   Unregister an panic handler to monitor M4 panic reset
+
+   Returns 0 on success or negative error code on failure
+
+     m4sensorhub - pointer to the main m4sensorhub data struct
+     index - M4 Sensor Hub panic handler to unresiter for
+*/
+int m4sensorhub_panic_unregister(struct m4sensorhub_data *m4sensorhub,
+	enum m4sensorhub_panichdl_index index)
+{
+	struct m4sensorhub_panicdata *panicdata;
+
+	if (!m4sensorhub || (index >= PANICHDL_MAX))
+		return -EINVAL;
+
+	panicdata = (struct m4sensorhub_panicdata *)m4sensorhub->panicdata;
+	mutex_lock(&panicdata->lock);
+	panicdata->funcs[index].callback = NULL;
+	panicdata->funcs[index].data = NULL;
+	mutex_unlock(&panicdata->lock);
+	KDEBUG(M4SH_NOTICE, "m4sensorhub: %s callback un-registered\n",
+			callback_name[index]);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(m4sensorhub_panic_unregister);
+
+
+/* m4sensorhub_panic_process()
+
+   Check M4 if it's panicked, use I2C to communicate with M4 panic handler
+   OMAP use the same i2c sequences to send command via i2c master, then M4
+   i2c slave program will handle these commands, it may have 2 slave programs
+   1. Normal i2c slave program handles all vaild banks'(limit on
+      M4SH_TYPE__NUM) command, for invalid bank, it always responses 0xFF
+   2. Panic i2c slave program handles panic bank(reserved 0xFF for it) command,
+      for others, it always responses 0x00
+
+   To detect whether M4 is panicked, the process should be
+   i. When OMAP got interrupt from M4, OMAP will check which irq is raised, it
+      send normal banks' command to M4, for panic case, it always returns 0x00,
+      so OMAP has a checkpoint as there's interrupt request from M4 without
+      active IRQ
+   ii.Then OMAP will confirm if M4 is panic via send panic bank command, if M4
+      is panicked, it will handle this bank and response panic magic code;
+      Otherwise, if no panic magic code returned from M4, it always means M4
+      isn't panicked.
+
+     m4sensorhub - pointer to the main m4sensorhub data struct
+	*/
+void m4sensorhub_panic_process(struct m4sensorhub_data *m4sensorhub)
+{
+	int i, ret;
+	union panic_buf buf;
+	struct m4sensorhub_panic_callback handler;
+
+	if (!m4sensorhub || !m4sensorhub->panicdata) {
+		KDEBUG(M4SH_ERROR, "m4sensorhub: Invalid parameter in %s!\n",\
+					__func__);
+		return;
+	}
+
+	m4sensorhub_reg_access_lock();
+
+	buf.in.bank = PANIC_BANK;
+	buf.in.cmd = PANIC_CMD_CHECK;
+	ret = m4sensorhub_i2c_write_read(m4sensorhub,\
+			(u8 *)&buf, sizeof(buf.in), sizeof(buf.data));
+	if ((ret != sizeof(buf.data)) || (buf.data != PANIC_RESP_CHECK)) {
+		/* TODO maybe we shall check if M4/OMAP i2c broken */
+		KDEBUG(M4SH_ERROR, "m4sensorhub: Unknown IRQ status! "\
+				"M4 panic handoff ret=%d, data=0x%x\n",\
+				ret, buf.data);
+		m4sensorhub_reg_access_unlock();
+		return;
+	}
+
+	KDEBUG(M4SH_ERROR, "m4sensorhub_panic: Detected M4 panic, reset M4!\n");
+	m4sensorhub->pdev->hw_reset(m4sensorhub);
+	msleep(100);
+	ret = m4sensorhub_load_firmware(m4sensorhub, 0);
+	if (ret < 0) {
+		KDEBUG(M4SH_ERROR, "m4sensorhub_panic: "\
+			"Failed to restart M4, ret = %d\n", ret);
+		BUG();
+	}
+
+	m4sensorhub_reg_access_unlock();
+
+	for (i = 0; i < PANICHDL_MAX; i++) {
+		handler = ((struct m4sensorhub_panicdata *)\
+				(m4sensorhub->panicdata))->funcs[i];
+		if (handler.callback) {
+			KDEBUG(M4SH_NOTICE, "m4sensorhub_panic: "\
+				"Calling %s as M4 restarted!\n",\
+				callback_name[i]);
+			handler.callback(m4sensorhub, handler.data);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(m4sensorhub_panic_process);