spmi: Linux driver framework for SPMI

System Power Management Interface (SPMI) is a specification
developed by the MIPI (Mobile Industry Process Interface) Alliance
optimized for the real time control of Power Management ICs (PMIC).

SPMI is a two-wire serial interface that supports up to 4 master
devices and up to 16 logical slaves.

The framework supports message APIs, multiple busses (1 controller
per bus) and multiple clients/slave devices per controller.

Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 199 insertions, 0 deletions

diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 45e921401b06..677e474fc273 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -432,6 +432,14 @@ struct spi_device_id {
         kernel_ulong_t driver_data;     /* Data private to the driver */
 };
 
+#define SPMI_NAME_SIZE  32
+#define SPMI_MODULE_PREFIX "spmi:"
+
+struct spmi_device_id {
+        char name[SPMI_NAME_SIZE];
+        kernel_ulong_t driver_data;     /* Data private to the driver */
+};
+
 /* dmi */
 enum dmi_field {
         DMI_NONE,
diff --git a/include/linux/spmi.h b/include/linux/spmi.h
new file mode 100644
index 000000000000..91f5eab9e428
--- /dev/null
+++ b/include/linux/spmi.h
@@ -0,0 +1,191 @@
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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.
+ */
+#ifndef _LINUX_SPMI_H
+#define _LINUX_SPMI_H
+
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+
+/* Maximum slave identifier */
+#define SPMI_MAX_SLAVE_ID               16
+
+/* SPMI Commands */
+#define SPMI_CMD_EXT_WRITE              0x00
+#define SPMI_CMD_RESET                  0x10
+#define SPMI_CMD_SLEEP                  0x11
+#define SPMI_CMD_SHUTDOWN               0x12
+#define SPMI_CMD_WAKEUP                 0x13
+#define SPMI_CMD_AUTHENTICATE           0x14
+#define SPMI_CMD_MSTR_READ              0x15
+#define SPMI_CMD_MSTR_WRITE             0x16
+#define SPMI_CMD_TRANSFER_BUS_OWNERSHIP 0x1A
+#define SPMI_CMD_DDB_MASTER_READ        0x1B
+#define SPMI_CMD_DDB_SLAVE_READ         0x1C
+#define SPMI_CMD_EXT_READ               0x20
+#define SPMI_CMD_EXT_WRITEL             0x30
+#define SPMI_CMD_EXT_READL              0x38
+#define SPMI_CMD_WRITE                  0x40
+#define SPMI_CMD_READ                   0x60
+#define SPMI_CMD_ZERO_WRITE             0x80
+
+/**
+ * struct spmi_device - Basic representation of an SPMI device
+ * @dev:        Driver model representation of the device.
+ * @ctrl:       SPMI controller managing the bus hosting this device.
+ * @usid:       This devices' Unique Slave IDentifier.
+ */
+struct spmi_device {
+        struct device           dev;
+        struct spmi_controller  *ctrl;
+        u8                      usid;
+};
+
+static inline struct spmi_device *to_spmi_device(struct device *d)
+{
+        return container_of(d, struct spmi_device, dev);
+}
+
+static inline void *spmi_device_get_drvdata(const struct spmi_device *sdev)
+{
+        return dev_get_drvdata(&sdev->dev);
+}
+
+static inline void spmi_device_set_drvdata(struct spmi_device *sdev, void *data)
+{
+        dev_set_drvdata(&sdev->dev, data);
+}
+
+struct spmi_device *spmi_device_alloc(struct spmi_controller *ctrl);
+
+static inline void spmi_device_put(struct spmi_device *sdev)
+{
+        if (sdev)
+                put_device(&sdev->dev);
+}
+
+int spmi_device_add(struct spmi_device *sdev);
+
+void spmi_device_remove(struct spmi_device *sdev);
+
+/**
+ * struct spmi_controller - interface to the SPMI master controller
+ * @dev:        Driver model representation of the device.
+ * @nr:         board-specific number identifier for this controller/bus
+ * @cmd:        sends a non-data command sequence on the SPMI bus.
+ * @read_cmd:   sends a register read command sequence on the SPMI bus.
+ * @write_cmd:  sends a register write command sequence on the SPMI bus.
+ */
+struct spmi_controller {
+        struct device           dev;
+        unsigned int            nr;
+        int     (*cmd)(struct spmi_controller *ctrl, u8 opcode, u8 sid);
+        int     (*read_cmd)(struct spmi_controller *ctrl, u8 opcode,
+                            u8 sid, u16 addr, u8 *buf, size_t len);
+        int     (*write_cmd)(struct spmi_controller *ctrl, u8 opcode,
+                             u8 sid, u16 addr, const u8 *buf, size_t len);
+};
+
+static inline struct spmi_controller *to_spmi_controller(struct device *d)
+{
+        return container_of(d, struct spmi_controller, dev);
+}
+
+static inline
+void *spmi_controller_get_drvdata(const struct spmi_controller *ctrl)
+{
+        return dev_get_drvdata(&ctrl->dev);
+}
+
+static inline void spmi_controller_set_drvdata(struct spmi_controller *ctrl,
+                                               void *data)
+{
+        dev_set_drvdata(&ctrl->dev, data);
+}
+
+struct spmi_controller *spmi_controller_alloc(struct device *parent,
+                                              size_t size);
+
+/**
+ * spmi_controller_put() - decrement controller refcount
+ * @ctrl        SPMI controller.
+ */
+static inline void spmi_controller_put(struct spmi_controller *ctrl)
+{
+        if (ctrl)
+                put_device(&ctrl->dev);
+}
+
+int spmi_controller_add(struct spmi_controller *ctrl);
+void spmi_controller_remove(struct spmi_controller *ctrl);
+
+/**
+ * struct spmi_driver - SPMI slave device driver
+ * @driver:     SPMI device drivers should initialize name and owner field of
+ *              this structure.
+ * @probe:      binds this driver to a SPMI device.
+ * @remove:     unbinds this driver from the SPMI device.
+ * @shutdown:   standard shutdown callback used during powerdown/halt.
+ * @suspend:    standard suspend callback used during system suspend.
+ * @resume:     standard resume callback used during system resume.
+ *
+ * If PM runtime support is desired for a slave, a device driver can call
+ * pm_runtime_put() from their probe() routine (and a balancing
+ * pm_runtime_get() in remove()).  PM runtime support for a slave is
+ * implemented by issuing a SLEEP command to the slave on runtime_suspend(),
+ * transitioning the slave into the SLEEP state.  On runtime_resume(), a WAKEUP
+ * command is sent to the slave to bring it back to ACTIVE.
+ */
+struct spmi_driver {
+        struct device_driver driver;
+        int     (*probe)(struct spmi_device *sdev);
+        void    (*remove)(struct spmi_device *sdev);
+};
+
+static inline struct spmi_driver *to_spmi_driver(struct device_driver *d)
+{
+        return container_of(d, struct spmi_driver, driver);
+}
+
+int spmi_driver_register(struct spmi_driver *sdrv);
+
+/**
+ * spmi_driver_unregister() - unregister an SPMI client driver
+ * @sdrv:       the driver to unregister
+ */
+static inline void spmi_driver_unregister(struct spmi_driver *sdrv)
+{
+        if (sdrv)
+                driver_unregister(&sdrv->driver);
+}
+
+#define module_spmi_driver(__spmi_driver) \
+        module_driver(__spmi_driver, spmi_driver_register, \
+                        spmi_driver_unregister)
+
+int spmi_register_read(struct spmi_device *sdev, u8 addr, u8 *buf);
+int spmi_ext_register_read(struct spmi_device *sdev, u8 addr, u8 *buf,
+                           size_t len);
+int spmi_ext_register_readl(struct spmi_device *sdev, u16 addr, u8 *buf,
+                            size_t len);
+int spmi_register_write(struct spmi_device *sdev, u8 addr, u8 data);
+int spmi_register_zero_write(struct spmi_device *sdev, u8 data);
+int spmi_ext_register_write(struct spmi_device *sdev, u8 addr,
+                            const u8 *buf, size_t len);
+int spmi_ext_register_writel(struct spmi_device *sdev, u16 addr,
+                             const u8 *buf, size_t len);
+int spmi_command_reset(struct spmi_device *sdev);
+int spmi_command_sleep(struct spmi_device *sdev);
+int spmi_command_wakeup(struct spmi_device *sdev);
+int spmi_command_shutdown(struct spmi_device *sdev);
+
+#endif