soc: ti: Add wkup_m3_ipc driver

Introduce a wkup_m3_ipc driver to handle communication between the MPU
and Cortex M3 wkup_m3 present on am335x.

This driver is responsible for actually booting the wkup_m3_rproc and
also handling all IPC which is done using the IPC registers in the control
module, a mailbox, and a separate interrupt back from the wkup_m3. A small
API is exposed for executing specific power commands, which include
configuring for low power mode, request a transition to a low power mode,
and status info on a previous transition.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/soc/ti/Kconfig

@@ -28,4 +28,14 @@ config KEYSTONE_NAVIGATOR_DMA
 
 	  If unsure, say N.
 
+config WKUP_M3_IPC
+	tristate "TI AMx3 Wkup-M3 IPC Driver"
+	depends on WKUP_M3_RPROC
+	depends on OMAP2PLUS_MBOX
+	help
+	  TI AM33XX and AM43XX have a Cortex M3, the Wakeup M3, to handle
+	  low power transitions. This IPC driver provides the necessary API
+	  to communicate and use the Wakeup M3 for PM features like suspend
+	  resume and boots it using wkup_m3_rproc driver.
+
 endif # SOC_TI

drivers/soc/ti/Makefile

@@ -4,3 +4,4 @@
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_QMSS)	+= knav_qmss.o
 knav_qmss-y := knav_qmss_queue.o knav_qmss_acc.o
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA)	+= knav_dma.o
+obj-$(CONFIG_WKUP_M3_IPC)		+= wkup_m3_ipc.o

include/linux/wkup_m3_ipc.h

+/*
+ * TI Wakeup M3 for AMx3 SoCs Power Management Routines
+ *
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ * Dave Gerlach <d-gerlach@ti.com>
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_WKUP_M3_IPC_H
+#define _LINUX_WKUP_M3_IPC_H
+
+#define WKUP_M3_DEEPSLEEP	1
+#define WKUP_M3_STANDBY		2
+#define WKUP_M3_IDLE		3
+
+#include <linux/mailbox_client.h>
+
+struct wkup_m3_ipc_ops;
+
+struct wkup_m3_ipc {
+	struct rproc *rproc;
+
+	void __iomem *ipc_mem_base;
+	struct device *dev;
+
+	int mem_type;
+	unsigned long resume_addr;
+	int state;
+
+	struct completion sync_complete;
+	struct mbox_client mbox_client;
+	struct mbox_chan *mbox;
+
+	struct wkup_m3_ipc_ops *ops;
+};
+
+struct wkup_m3_ipc_ops {
+	void (*set_mem_type)(struct wkup_m3_ipc *m3_ipc, int mem_type);
+	void (*set_resume_address)(struct wkup_m3_ipc *m3_ipc, void *addr);
+	int (*prepare_low_power)(struct wkup_m3_ipc *m3_ipc, int state);
+	int (*finish_low_power)(struct wkup_m3_ipc *m3_ipc);
+	int (*request_pm_status)(struct wkup_m3_ipc *m3_ipc);
+};
+
+struct wkup_m3_ipc *wkup_m3_ipc_get(void);
+void wkup_m3_ipc_put(struct wkup_m3_ipc *m3_ipc);
+#endif /* _LINUX_WKUP_M3_IPC_H */