powerpc: Move include files to arch/powerpc/include/asm

from include/asm-powerpc.  This is the result of a

mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm

Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly.  Of the latter only
one was outside the arch code and it is a driver only built for powerpc.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 700 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/smu.h b/arch/powerpc/include/asm/smu.h
new file mode 100644
index 000000000000..7ae2753da565
--- /dev/null
+++ b/arch/powerpc/include/asm/smu.h
@@ -0,0 +1,700 @@
+#ifndef _SMU_H
+#define _SMU_H
+
+/*
+ * Definitions for talking to the SMU chip in newer G5 PowerMacs
+ */
+#ifdef __KERNEL__
+#include <linux/list.h>
+#endif
+#include <linux/types.h>
+
+/*
+ * Known SMU commands
+ *
+ * Most of what is below comes from looking at the Open Firmware driver,
+ * though this is still incomplete and could use better documentation here
+ * or there...
+ */
+
+
+/*
+ * Partition info commands
+ *
+ * These commands are used to retrieve the sdb-partition-XX datas from
+ * the SMU. The length is always 2. First byte is the subcommand code
+ * and second byte is the partition ID.
+ *
+ * The reply is 6 bytes:
+ *
+ *  - 0..1 : partition address
+ *  - 2    : a byte containing the partition ID
+ *  - 3    : length (maybe other bits are rest of header ?)
+ *
+ * The data must then be obtained with calls to another command:
+ * SMU_CMD_MISC_ee_GET_DATABLOCK_REC (described below).
+ */
+#define SMU_CMD_PARTITION_COMMAND		0x3e
+#define   SMU_CMD_PARTITION_LATEST		0x01
+#define   SMU_CMD_PARTITION_BASE		0x02
+#define   SMU_CMD_PARTITION_UPDATE		0x03
+
+
+/*
+ * Fan control
+ *
+ * This is a "mux" for fan control commands. The command seem to
+ * act differently based on the number of arguments. With 1 byte
+ * of argument, this seem to be queries for fans status, setpoint,
+ * etc..., while with 0xe arguments, we will set the fans speeds.
+ *
+ * Queries (1 byte arg):
+ * ---------------------
+ *
+ * arg=0x01: read RPM fans status
+ * arg=0x02: read RPM fans setpoint
+ * arg=0x11: read PWM fans status
+ * arg=0x12: read PWM fans setpoint
+ *
+ * the "status" queries return the current speed while the "setpoint" ones
+ * return the programmed/target speed. It _seems_ that the result is a bit
+ * mask in the first byte of active/available fans, followed by 6 words (16
+ * bits) containing the requested speed.
+ *
+ * Setpoint (14 bytes arg):
+ * ------------------------
+ *
+ * first arg byte is 0 for RPM fans and 0x10 for PWM. Second arg byte is the
+ * mask of fans affected by the command. Followed by 6 words containing the
+ * setpoint value for selected fans in the mask (or 0 if mask value is 0)
+ */
+#define SMU_CMD_FAN_COMMAND			0x4a
+
+
+/*
+ * Battery access
+ *
+ * Same command number as the PMU, could it be same syntax ?
+ */
+#define SMU_CMD_BATTERY_COMMAND			0x6f
+#define   SMU_CMD_GET_BATTERY_INFO		0x00
+
+/*
+ * Real time clock control
+ *
+ * This is a "mux", first data byte contains the "sub" command.
+ * The "RTC" part of the SMU controls the date, time, powerup
+ * timer, but also a PRAM
+ *
+ * Dates are in BCD format on 7 bytes:
+ * [sec] [min] [hour] [weekday] [month day] [month] [year]
+ * with month being 1 based and year minus 100
+ */
+#define SMU_CMD_RTC_COMMAND			0x8e
+#define   SMU_CMD_RTC_SET_PWRUP_TIMER		0x00 /* i: 7 bytes date */
+#define   SMU_CMD_RTC_GET_PWRUP_TIMER		0x01 /* o: 7 bytes date */
+#define   SMU_CMD_RTC_STOP_PWRUP_TIMER		0x02
+#define   SMU_CMD_RTC_SET_PRAM_BYTE_ACC		0x20 /* i: 1 byte (address?) */
+#define   SMU_CMD_RTC_SET_PRAM_AUTOINC		0x21 /* i: 1 byte (data?) */
+#define   SMU_CMD_RTC_SET_PRAM_LO_BYTES 	0x22 /* i: 10 bytes */
+#define   SMU_CMD_RTC_SET_PRAM_HI_BYTES 	0x23 /* i: 10 bytes */
+#define   SMU_CMD_RTC_GET_PRAM_BYTE		0x28 /* i: 1 bytes (address?) */
+#define   SMU_CMD_RTC_GET_PRAM_LO_BYTES 	0x29 /* o: 10 bytes */
+#define   SMU_CMD_RTC_GET_PRAM_HI_BYTES 	0x2a /* o: 10 bytes */
+#define	  SMU_CMD_RTC_SET_DATETIME		0x80 /* i: 7 bytes date */
+#define   SMU_CMD_RTC_GET_DATETIME		0x81 /* o: 7 bytes date */
+
+ /*
+  * i2c commands
+  *
+  * To issue an i2c command, first is to send a parameter block to the
+  * the SMU. This is a command of type 0x9a with 9 bytes of header
+  * eventually followed by data for a write:
+  *
+  * 0: bus number (from device-tree usually, SMU has lots of busses !)
+  * 1: transfer type/format (see below)
+  * 2: device address. For combined and combined4 type transfers, this
+  *    is the "write" version of the address (bit 0x01 cleared)
+  * 3: subaddress length (0..3)
+  * 4: subaddress byte 0 (or only byte for subaddress length 1)
+  * 5: subaddress byte 1
+  * 6: subaddress byte 2
+  * 7: combined address (device address for combined mode data phase)
+  * 8: data length
+  *
+  * The transfer types are the same good old Apple ones it seems,
+  * that is:
+  *   - 0x00: Simple transfer
+  *   - 0x01: Subaddress transfer (addr write + data tx, no restart)
+  *   - 0x02: Combined transfer (addr write + restart + data tx)
+  *
+  * This is then followed by actual data for a write.
+  *
+  * At this point, the OF driver seems to have a limitation on transfer
+  * sizes of 0xd bytes on reads and 0x5 bytes on writes. I do not know
+  * wether this is just an OF limit due to some temporary buffer size
+  * or if this is an SMU imposed limit. This driver has the same limitation
+  * for now as I use a 0x10 bytes temporary buffer as well
+  *
+  * Once that is completed, a response is expected from the SMU. This is
+  * obtained via a command of type 0x9a with a length of 1 byte containing
+  * 0 as the data byte. OF also fills the rest of the data buffer with 0xff's
+  * though I can't tell yet if this is actually necessary. Once this command
+  * is complete, at this point, all I can tell is what OF does. OF tests
+  * byte 0 of the reply:
+  *   - on read, 0xfe or 0xfc : bus is busy, wait (see below) or nak ?
+  *   - on read, 0x00 or 0x01 : reply is in buffer (after the byte 0)
+  *   - on write, < 0 -> failure (immediate exit)
+  *   - else, OF just exists (without error, weird)
+  *
+  * So on read, there is this wait-for-busy thing when getting a 0xfc or
+  * 0xfe result. OF does a loop of up to 64 retries, waiting 20ms and
+  * doing the above again until either the retries expire or the result
+  * is no longer 0xfe or 0xfc
+  *
+  * The Darwin I2C driver is less subtle though. On any non-success status
+  * from the response command, it waits 5ms and tries again up to 20 times,
+  * it doesn't differenciate between fatal errors or "busy" status.
+  *
+  * This driver provides an asynchronous paramblock based i2c command
+  * interface to be used either directly by low level code or by a higher
+  * level driver interfacing to the linux i2c layer. The current
+  * implementation of this relies on working timers & timer interrupts
+  * though, so be careful of calling context for now. This may be "fixed"
+  * in the future by adding a polling facility.
+  */
+#define SMU_CMD_I2C_COMMAND			0x9a
+          /* transfer types */
+#define   SMU_I2C_TRANSFER_SIMPLE	0x00
+#define   SMU_I2C_TRANSFER_STDSUB	0x01
+#define   SMU_I2C_TRANSFER_COMBINED	0x02
+
+/*
+ * Power supply control
+ *
+ * The "sub" command is an ASCII string in the data, the
+ * data length is that of the string.
+ *
+ * The VSLEW command can be used to get or set the voltage slewing.
+ *  - length 5 (only "VSLEW") : it returns "DONE" and 3 bytes of
+ *    reply at data offset 6, 7 and 8.
+ *  - length 8 ("VSLEWxyz") has 3 additional bytes appended, and is
+ *    used to set the voltage slewing point. The SMU replies with "DONE"
+ * I yet have to figure out their exact meaning of those 3 bytes in
+ * both cases. They seem to be:
+ *  x = processor mask
+ *  y = op. point index
+ *  z = processor freq. step index
+ * I haven't yet decyphered result codes
+ *
+ */
+#define SMU_CMD_POWER_COMMAND			0xaa
+#define   SMU_CMD_POWER_RESTART		       	"RESTART"
+#define   SMU_CMD_POWER_SHUTDOWN		"SHUTDOWN"
+#define   SMU_CMD_POWER_VOLTAGE_SLEW		"VSLEW"
+
+/*
+ * Read ADC sensors
+ *
+ * This command takes one byte of parameter: the sensor ID (or "reg"
+ * value in the device-tree) and returns a 16 bits value
+ */
+#define SMU_CMD_READ_ADC			0xd8
+
+
+/* Misc commands
+ *
+ * This command seem to be a grab bag of various things
+ *
+ * Parameters:
+ *   1: subcommand
+ */
+#define SMU_CMD_MISC_df_COMMAND			0xdf
+
+/*
+ * Sets "system ready" status
+ *
+ * I did not yet understand how it exactly works or what it does.
+ *
+ * Guessing from OF code, 0x02 activates the display backlight. Apple uses/used
+ * the same codebase for all OF versions. On PowerBooks, this command would
+ * enable the backlight. For the G5s, it only activates the front LED. However,
+ * don't take this for granted.
+ *
+ * Parameters:
+ *   2: status [0x00, 0x01 or 0x02]
+ */
+#define   SMU_CMD_MISC_df_SET_DISPLAY_LIT	0x02
+
+/*
+ * Sets mode of power switch.
+ *
+ * What this actually does is not yet known. Maybe it enables some interrupt.
+ *
+ * Parameters:
+ *   2: enable power switch? [0x00 or 0x01]
+ *   3 (optional): enable nmi? [0x00 or 0x01]
+ *
+ * Returns:
+ *   If parameter 2 is 0x00 and parameter 3 is not specified, returns wether
+ *   NMI is enabled. Otherwise unknown.
+ */
+#define   SMU_CMD_MISC_df_NMI_OPTION		0x04
+
+/* Sets LED dimm offset.
+ *
+ * The front LED dimms itself during sleep. Its brightness (or, well, the PWM
+ * frequency) depends on current time. Therefore, the SMU needs to know the
+ * timezone.
+ *
+ * Parameters:
+ *   2-8: unknown (BCD coding)
+ */
+#define   SMU_CMD_MISC_df_DIMM_OFFSET		0x99
+
+
+/*
+ * Version info commands
+ *
+ * Parameters:
+ *   1 (optional): Specifies version part to retrieve
+ *
+ * Returns:
+ *   Version value
+ */
+#define SMU_CMD_VERSION_COMMAND			0xea
+#define   SMU_VERSION_RUNNING			0x00
+#define   SMU_VERSION_BASE			0x01
+#define   SMU_VERSION_UPDATE			0x02
+
+
+/*
+ * Switches
+ *
+ * These are switches whose status seems to be known to the SMU.
+ *
+ * Parameters:
+ *   none
+ *
+ * Result:
+ *   Switch bits (ORed, see below)
+ */
+#define SMU_CMD_SWITCHES			0xdc
+
+/* Switches bits */
+#define SMU_SWITCH_CASE_CLOSED			0x01
+#define SMU_SWITCH_AC_POWER			0x04
+#define SMU_SWITCH_POWER_SWITCH			0x08
+
+
+/*
+ * Misc commands
+ *
+ * This command seem to be a grab bag of various things
+ *
+ * SMU_CMD_MISC_ee_GET_DATABLOCK_REC is used, among others, to
+ * transfer blocks of data from the SMU. So far, I've decrypted it's
+ * usage to retrieve partition data. In order to do that, you have to
+ * break your transfer in "chunks" since that command cannot transfer
+ * more than a chunk at a time. The chunk size used by OF is 0xe bytes,
+ * but it seems that the darwin driver will let you do 0x1e bytes if
+ * your "PMU" version is >= 0x30. You can get the "PMU" version apparently
+ * either in the last 16 bits of property "smu-version-pmu" or as the 16
+ * bytes at offset 1 of "smu-version-info"
+ *
+ * For each chunk, the command takes 7 bytes of arguments:
+ *  byte 0: subcommand code (0x02)
+ *  byte 1: 0x04 (always, I don't know what it means, maybe the address
+ *                space to use or some other nicety. It's hard coded in OF)
+ *  byte 2..5: SMU address of the chunk (big endian 32 bits)
+ *  byte 6: size to transfer (up to max chunk size)
+ *
+ * The data is returned directly
+ */
+#define SMU_CMD_MISC_ee_COMMAND			0xee
+#define   SMU_CMD_MISC_ee_GET_DATABLOCK_REC	0x02
+
+/* Retrieves currently used watts.
+ *
+ * Parameters:
+ *   1: 0x03 (Meaning unknown)
+ */
+#define   SMU_CMD_MISC_ee_GET_WATTS		0x03
+
+#define   SMU_CMD_MISC_ee_LEDS_CTRL		0x04 /* i: 00 (00,01) [00] */
+#define   SMU_CMD_MISC_ee_GET_DATA		0x05 /* i: 00 , o: ?? */
+
+
+/*
+ * Power related commands
+ *
+ * Parameters:
+ *   1: subcommand
+ */
+#define SMU_CMD_POWER_EVENTS_COMMAND		0x8f
+
+/* SMU_POWER_EVENTS subcommands */
+enum {
+	SMU_PWR_GET_POWERUP_EVENTS      = 0x00,
+	SMU_PWR_SET_POWERUP_EVENTS      = 0x01,
+	SMU_PWR_CLR_POWERUP_EVENTS      = 0x02,
+	SMU_PWR_GET_WAKEUP_EVENTS       = 0x03,
+	SMU_PWR_SET_WAKEUP_EVENTS       = 0x04,
+	SMU_PWR_CLR_WAKEUP_EVENTS       = 0x05,
+
+	/*
+	 * Get last shutdown cause
+	 *
+	 * Returns:
+	 *   1 byte (signed char): Last shutdown cause. Exact meaning unknown.
+	 */
+	SMU_PWR_LAST_SHUTDOWN_CAUSE	= 0x07,
+
+	/*
+	 * Sets or gets server ID. Meaning or use is unknown.
+	 *
+	 * Parameters:
+	 *   2 (optional): Set server ID (1 byte)
+	 *
+	 * Returns:
+	 *   1 byte (server ID?)
+	 */
+	SMU_PWR_SERVER_ID		= 0x08,
+};
+
+/* Power events wakeup bits */
+enum {
+	SMU_PWR_WAKEUP_KEY              = 0x01, /* Wake on key press */
+	SMU_PWR_WAKEUP_AC_INSERT        = 0x02, /* Wake on AC adapter plug */
+	SMU_PWR_WAKEUP_AC_CHANGE        = 0x04,
+	SMU_PWR_WAKEUP_LID_OPEN         = 0x08,
+	SMU_PWR_WAKEUP_RING             = 0x10,
+};
+
+
+/*
+ * - Kernel side interface -
+ */
+
+#ifdef __KERNEL__
+
+/*
+ * Asynchronous SMU commands
+ *
+ * Fill up this structure and submit it via smu_queue_command(),
+ * and get notified by the optional done() callback, or because
+ * status becomes != 1
+ */
+
+struct smu_cmd;
+
+struct smu_cmd
+{
+	/* public */
+	u8			cmd;		/* command */
+	int			data_len;	/* data len */
+	int			reply_len;	/* reply len */
+	void			*data_buf;	/* data buffer */
+	void			*reply_buf;	/* reply buffer */
+	int			status;		/* command status */
+	void			(*done)(struct smu_cmd *cmd, void *misc);
+	void			*misc;
+
+	/* private */
+	struct list_head	link;
+};
+
+/*
+ * Queues an SMU command, all fields have to be initialized
+ */
+extern int smu_queue_cmd(struct smu_cmd *cmd);
+
+/*
+ * Simple command wrapper. This structure embeds a small buffer
+ * to ease sending simple SMU commands from the stack
+ */
+struct smu_simple_cmd
+{
+	struct smu_cmd	cmd;
+	u8	       	buffer[16];
+};
+
+/*
+ * Queues a simple command. All fields will be initialized by that
+ * function
+ */
+extern int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
+			    unsigned int data_len,
+			    void (*done)(struct smu_cmd *cmd, void *misc),
+			    void *misc,
+			    ...);
+
+/*
+ * Completion helper. Pass it to smu_queue_simple or as 'done'
+ * member to smu_queue_cmd, it will call complete() on the struct
+ * completion passed in the "misc" argument
+ */
+extern void smu_done_complete(struct smu_cmd *cmd, void *misc);
+
+/*
+ * Synchronous helpers. Will spin-wait for completion of a command
+ */
+extern void smu_spinwait_cmd(struct smu_cmd *cmd);
+
+static inline void smu_spinwait_simple(struct smu_simple_cmd *scmd)
+{
+	smu_spinwait_cmd(&scmd->cmd);
+}
+
+/*
+ * Poll routine to call if blocked with irqs off
+ */
+extern void smu_poll(void);
+
+
+/*
+ * Init routine, presence check....
+ */
+extern int smu_init(void);
+extern int smu_present(void);
+struct of_device;
+extern struct of_device *smu_get_ofdev(void);
+
+
+/*
+ * Common command wrappers
+ */
+extern void smu_shutdown(void);
+extern void smu_restart(void);
+struct rtc_time;
+extern int smu_get_rtc_time(struct rtc_time *time, int spinwait);
+extern int smu_set_rtc_time(struct rtc_time *time, int spinwait);
+
+/*
+ * SMU command buffer absolute address, exported by pmac_setup,
+ * this is allocated very early during boot.
+ */
+extern unsigned long smu_cmdbuf_abs;
+
+
+/*
+ * Kenrel asynchronous i2c interface
+ */
+
+#define SMU_I2C_READ_MAX	0x1d
+#define SMU_I2C_WRITE_MAX	0x15
+
+/* SMU i2c header, exactly matches i2c header on wire */
+struct smu_i2c_param
+{
+	u8	bus;		/* SMU bus ID (from device tree) */
+	u8	type;		/* i2c transfer type */
+	u8	devaddr;	/* device address (includes direction) */
+	u8	sublen;		/* subaddress length */
+	u8	subaddr[3];	/* subaddress */
+	u8	caddr;		/* combined address, filled by SMU driver */
+	u8	datalen;	/* length of transfer */
+	u8	data[SMU_I2C_READ_MAX];	/* data */
+};
+
+struct smu_i2c_cmd
+{
+	/* public */
+	struct smu_i2c_param	info;
+	void			(*done)(struct smu_i2c_cmd *cmd, void *misc);
+	void			*misc;
+	int			status; /* 1 = pending, 0 = ok, <0 = fail */
+
+	/* private */
+	struct smu_cmd		scmd;
+	int			read;
+	int			stage;
+	int			retries;
+	u8			pdata[32];
+	struct list_head	link;
+};
+
+/*
+ * Call this to queue an i2c command to the SMU. You must fill info,
+ * including info.data for a write, done and misc.
+ * For now, no polling interface is provided so you have to use completion
+ * callback.
+ */
+extern int smu_queue_i2c(struct smu_i2c_cmd *cmd);
+
+
+#endif /* __KERNEL__ */
+
+
+/*
+ * - SMU "sdb" partitions informations -
+ */
+
+
+/*
+ * Partition header format
+ */
+struct smu_sdbp_header {
+	__u8	id;
+	__u8	len;
+	__u8	version;
+	__u8	flags;
+};
+
+
+ /*
+ * demangle 16 and 32 bits integer in some SMU partitions
+ * (currently, afaik, this concerns only the FVT partition
+ * (0x12)
+ */
+#define SMU_U16_MIX(x)	le16_to_cpu(x);
+#define SMU_U32_MIX(x)  ((((x) & 0xff00ff00u) >> 8)|(((x) & 0x00ff00ffu) << 8))
+
+
+/* This is the definition of the SMU sdb-partition-0x12 table (called
+ * CPU F/V/T operating points in Darwin). The definition for all those
+ * SMU tables should be moved to some separate file
+ */
+#define SMU_SDB_FVT_ID			0x12
+
+struct smu_sdbp_fvt {
+	__u32	sysclk;			/* Base SysClk frequency in Hz for
+					 * this operating point. Value need to
+					 * be unmixed with SMU_U32_MIX()
+					 */
+	__u8	pad;
+	__u8	maxtemp;		/* Max temp. supported by this
+					 * operating point
+					 */
+
+	__u16	volts[3];		/* CPU core voltage for the 3
+					 * PowerTune modes, a mode with
+					 * 0V = not supported. Value need
+					 * to be unmixed with SMU_U16_MIX()
+					 */
+};
+
+/* This partition contains voltage & current sensor calibration
+ * informations
+ */
+#define SMU_SDB_CPUVCP_ID		0x21
+
+struct smu_sdbp_cpuvcp {
+	__u16	volt_scale;		/* u4.12 fixed point */
+	__s16	volt_offset;		/* s4.12 fixed point */
+	__u16	curr_scale;		/* u4.12 fixed point */
+	__s16	curr_offset;		/* s4.12 fixed point */
+	__s32	power_quads[3];		/* s4.28 fixed point */
+};
+
+/* This partition contains CPU thermal diode calibration
+ */
+#define SMU_SDB_CPUDIODE_ID		0x18
+
+struct smu_sdbp_cpudiode {
+	__u16	m_value;		/* u1.15 fixed point */
+	__s16	b_value;		/* s10.6 fixed point */
+
+};
+
+/* This partition contains Slots power calibration
+ */
+#define SMU_SDB_SLOTSPOW_ID		0x78
+
+struct smu_sdbp_slotspow {
+	__u16	pow_scale;		/* u4.12 fixed point */
+	__s16	pow_offset;		/* s4.12 fixed point */
+};
+
+/* This partition contains machine specific version information about
+ * the sensor/control layout
+ */
+#define SMU_SDB_SENSORTREE_ID		0x25
+
+struct smu_sdbp_sensortree {
+	__u8	model_id;
+	__u8	unknown[3];
+};
+
+/* This partition contains CPU thermal control PID informations. So far
+ * only single CPU machines have been seen with an SMU, so we assume this
+ * carries only informations for those
+ */
+#define SMU_SDB_CPUPIDDATA_ID		0x17
+
+struct smu_sdbp_cpupiddata {
+	__u8	unknown1;
+	__u8	target_temp_delta;
+	__u8	unknown2;
+	__u8	history_len;
+	__s16	power_adj;
+	__u16	max_power;
+	__s32	gp,gr,gd;
+};
+
+
+/* Other partitions without known structures */
+#define SMU_SDB_DEBUG_SWITCHES_ID	0x05
+
+#ifdef __KERNEL__
+/*
+ * This returns the pointer to an SMU "sdb" partition data or NULL
+ * if not found. The data format is described below
+ */
+extern const struct smu_sdbp_header *smu_get_sdb_partition(int id,
+					unsigned int *size);
+
+/* Get "sdb" partition data from an SMU satellite */
+extern struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id,
+					int id, unsigned int *size);
+
+
+#endif /* __KERNEL__ */
+
+
+/*
+ * - Userland interface -
+ */
+
+/*
+ * A given instance of the device can be configured for 2 different
+ * things at the moment:
+ *
+ *  - sending SMU commands (default at open() time)
+ *  - receiving SMU events (not yet implemented)
+ *
+ * Commands are written with write() of a command block. They can be
+ * "driver" commands (for example to switch to event reception mode)
+ * or real SMU commands. They are made of a header followed by command
+ * data if any.
+ *
+ * For SMU commands (not for driver commands), you can then read() back
+ * a reply. The reader will be blocked or not depending on how the device
+ * file is opened. poll() isn't implemented yet. The reply will consist
+ * of a header as well, followed by the reply data if any. You should
+ * always provide a buffer large enough for the maximum reply data, I
+ * recommand one page.
+ *
+ * It is illegal to send SMU commands through a file descriptor configured
+ * for events reception
+ *
+ */
+struct smu_user_cmd_hdr
+{
+	__u32		cmdtype;
+#define SMU_CMDTYPE_SMU			0	/* SMU command */
+#define SMU_CMDTYPE_WANTS_EVENTS	1	/* switch fd to events mode */
+#define SMU_CMDTYPE_GET_PARTITION	2	/* retrieve an sdb partition */
+
+	__u8		cmd;			/* SMU command byte */
+	__u8		pad[3];			/* padding */
+	__u32		data_len;		/* Length of data following */
+};
+
+struct smu_user_reply_hdr
+{
+	__u32		status;			/* Command status */
+	__u32		reply_len;		/* Length of data follwing */
+};
+
+#endif /*  _SMU_H */