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Commit 9d715fa0 authored by Vinod Koul's avatar Vinod Koul Committed by Greg Kroah-Hartman
Browse files

soundwire: Add IO transfer 



SoundWire bus supports read or write register(s) for SoundWire Slave
device. sdw_read() and sdw_write() APIs are provided for single
register read/write. sdw_nread() and sdw_nwrite() for operations on
contiguous registers.

Signed-off-by: default avatarSanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
Acked-By: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6f3da1f3

drivers/soundwire/bus.c

+272 −0
Original line number Original line Diff line number Diff line
@@ -3,6 +3,8 @@ 




#include <linux/acpi.h>

#include <linux/acpi.h>

#include <linux/mod_devicetable.h>

#include <linux/mod_devicetable.h>

#include <linux/pm_runtime.h>

#include <linux/soundwire/sdw_registers.h>

#include <linux/soundwire/sdw.h>

#include <linux/soundwire/sdw.h>

#include "bus.h"

#include "bus.h"
@@ -22,6 +24,12 @@ int sdw_add_bus_master(struct sdw_bus *bus) 
		return -ENODEV;

		return -ENODEV;

	}

	}





	if (!bus->ops) {

		dev_err(bus->dev, "SoundWire Bus ops are not set");

		return -EINVAL;

	}



	mutex_init(&bus->msg_lock);

	mutex_init(&bus->bus_lock);

	mutex_init(&bus->bus_lock);

	INIT_LIST_HEAD(&bus->slaves);

	INIT_LIST_HEAD(&bus->slaves);
@@ -102,6 +110,270 @@ void sdw_delete_bus_master(struct sdw_bus *bus) 
}

}

EXPORT_SYMBOL(sdw_delete_bus_master);

EXPORT_SYMBOL(sdw_delete_bus_master);





/*

 * SDW IO Calls

 */



static inline int find_response_code(enum sdw_command_response resp)

{

	switch (resp) {

	case SDW_CMD_OK:

		return 0;



	case SDW_CMD_IGNORED:

		return -ENODATA;



	case SDW_CMD_TIMEOUT:

		return -ETIMEDOUT;



	default:

		return -EIO;

	}

}



static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)

{

	int retry = bus->prop.err_threshold;

	enum sdw_command_response resp;

	int ret = 0, i;



	for (i = 0; i <= retry; i++) {

		resp = bus->ops->xfer_msg(bus, msg);

		ret = find_response_code(resp);



		/* if cmd is ok or ignored return */

		if (ret == 0 || ret == -ENODATA)

			return ret;

	}



	return ret;

}



static inline int do_transfer_defer(struct sdw_bus *bus,

			struct sdw_msg *msg, struct sdw_defer *defer)

{

	int retry = bus->prop.err_threshold;

	enum sdw_command_response resp;

	int ret = 0, i;



	defer->msg = msg;

	defer->length = msg->len;



	for (i = 0; i <= retry; i++) {

		resp = bus->ops->xfer_msg_defer(bus, msg, defer);

		ret = find_response_code(resp);

		/* if cmd is ok or ignored return */

		if (ret == 0 || ret == -ENODATA)

			return ret;

	}



	return ret;

}



static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num)

{

	int retry = bus->prop.err_threshold;

	enum sdw_command_response resp;

	int ret = 0, i;



	for (i = 0; i <= retry; i++) {

		resp = bus->ops->reset_page_addr(bus, dev_num);

		ret = find_response_code(resp);

		/* if cmd is ok or ignored return */

		if (ret == 0 || ret == -ENODATA)

			return ret;

	}



	return ret;

}



/**

 * sdw_transfer() - Synchronous transfer message to a SDW Slave device

 * @bus: SDW bus

 * @msg: SDW message to be xfered

 */

int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)

{

	int ret;



	mutex_lock(&bus->msg_lock);



	ret = do_transfer(bus, msg);

	if (ret != 0 && ret != -ENODATA)

		dev_err(bus->dev, "trf on Slave %d failed:%d\n",

				msg->dev_num, ret);



	if (msg->page)

		sdw_reset_page(bus, msg->dev_num);



	mutex_unlock(&bus->msg_lock);



	return ret;

}



/**

 * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device

 * @bus: SDW bus

 * @msg: SDW message to be xfered

 * @defer: Defer block for signal completion

 *

 * Caller needs to hold the msg_lock lock while calling this

 */

int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,

				struct sdw_defer *defer)

{

	int ret;



	if (!bus->ops->xfer_msg_defer)

		return -ENOTSUPP;



	ret = do_transfer_defer(bus, msg, defer);

	if (ret != 0 && ret != -ENODATA)

		dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",

				msg->dev_num, ret);



	if (msg->page)

		sdw_reset_page(bus, msg->dev_num);



	return ret;

}





int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,

		u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)

{

	memset(msg, 0, sizeof(*msg));

	msg->addr = addr; /* addr is 16 bit and truncated here */

	msg->len = count;

	msg->dev_num = dev_num;

	msg->flags = flags;

	msg->buf = buf;

	msg->ssp_sync = false;

	msg->page = false;



	if (addr < SDW_REG_NO_PAGE) { /* no paging area */

		return 0;

	} else if (addr >= SDW_REG_MAX) { /* illegal addr */

		pr_err("SDW: Invalid address %x passed\n", addr);

		return -EINVAL;

	}



	if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */

		if (slave && !slave->prop.paging_support)

			return 0;

		/* no need for else as that will fall thru to paging */

	}



	/* paging mandatory */

	if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {

		pr_err("SDW: Invalid device for paging :%d\n", dev_num);

		return -EINVAL;

	}



	if (!slave) {

		pr_err("SDW: No slave for paging addr\n");

		return -EINVAL;

	} else if (!slave->prop.paging_support) {

		dev_err(&slave->dev,

			"address %x needs paging but no support", addr);

		return -EINVAL;

	}



	msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK));

	msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK));

	msg->addr |= BIT(15);

	msg->page = true;



	return 0;

}



/**

 * sdw_nread() - Read "n" contiguous SDW Slave registers

 * @slave: SDW Slave

 * @addr: Register address

 * @count: length

 * @val: Buffer for values to be read

 */

int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)

{

	struct sdw_msg msg;

	int ret;



	ret = sdw_fill_msg(&msg, slave, addr, count,

			slave->dev_num, SDW_MSG_FLAG_READ, val);

	if (ret < 0)

		return ret;



	ret = pm_runtime_get_sync(slave->bus->dev);

	if (!ret)

		return ret;



	ret = sdw_transfer(slave->bus, &msg);

	pm_runtime_put(slave->bus->dev);



	return ret;

}

EXPORT_SYMBOL(sdw_nread);



/**

 * sdw_nwrite() - Write "n" contiguous SDW Slave registers

 * @slave: SDW Slave

 * @addr: Register address

 * @count: length

 * @val: Buffer for values to be read

 */

int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)

{

	struct sdw_msg msg;

	int ret;



	ret = sdw_fill_msg(&msg, slave, addr, count,

			slave->dev_num, SDW_MSG_FLAG_WRITE, val);

	if (ret < 0)

		return ret;



	ret = pm_runtime_get_sync(slave->bus->dev);

	if (!ret)

		return ret;



	ret = sdw_transfer(slave->bus, &msg);

	pm_runtime_put(slave->bus->dev);



	return ret;

}

EXPORT_SYMBOL(sdw_nwrite);



/**

 * sdw_read() - Read a SDW Slave register

 * @slave: SDW Slave

 * @addr: Register address

 */

int sdw_read(struct sdw_slave *slave, u32 addr)

{

	u8 buf;

	int ret;



	ret = sdw_nread(slave, addr, 1, &buf);

	if (ret < 0)

		return ret;

	else

		return buf;

}

EXPORT_SYMBOL(sdw_read);



/**

 * sdw_write() - Write a SDW Slave register

 * @slave: SDW Slave

 * @addr: Register address

 * @value: Register value

 */

int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)

{

	return sdw_nwrite(slave, addr, 1, &value);



}

EXPORT_SYMBOL(sdw_write);



void sdw_extract_slave_id(struct sdw_bus *bus,

void sdw_extract_slave_id(struct sdw_bus *bus,

			u64 addr, struct sdw_slave_id *id)

			u64 addr, struct sdw_slave_id *id)

{

{

drivers/soundwire/bus.h

+36 −0
Original line number Original line Diff line number Diff line
@@ -16,4 +16,40 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus) 
void sdw_extract_slave_id(struct sdw_bus *bus,

void sdw_extract_slave_id(struct sdw_bus *bus,

			u64 addr, struct sdw_slave_id *id);

			u64 addr, struct sdw_slave_id *id);





enum {

	SDW_MSG_FLAG_READ = 0,

	SDW_MSG_FLAG_WRITE,

};



/**

 * struct sdw_msg - Message structure

 * @addr: Register address accessed in the Slave

 * @len: number of messages

 * @dev_num: Slave device number

 * @addr_page1: SCP address page 1 Slave register

 * @addr_page2: SCP address page 2 Slave register

 * @flags: transfer flags, indicate if xfer is read or write

 * @buf: message data buffer

 * @ssp_sync: Send message at SSP (Stream Synchronization Point)

 * @page: address requires paging

 */

struct sdw_msg {

	u16 addr;

	u16 len;

	u8 dev_num;

	u8 addr_page1;

	u8 addr_page2;

	u8 flags;

	u8 *buf;

	bool ssp_sync;

	bool page;

};



int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg);

int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,

				struct sdw_defer *defer);



int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,

		u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf);



#endif /* __SDW_BUS_H */
 
#endif /* __SDW_BUS_H */

include/linux/soundwire/sdw.h

+57 −0
Original line number Original line Diff line number Diff line
@@ -38,6 +38,27 @@ enum sdw_slave_status { 
	SDW_SLAVE_RESERVED = 3,

	SDW_SLAVE_RESERVED = 3,

};

};





/**

 * enum sdw_command_response - Command response as defined by SDW spec

 * @SDW_CMD_OK: cmd was successful

 * @SDW_CMD_IGNORED: cmd was ignored

 * @SDW_CMD_FAIL: cmd was NACKed

 * @SDW_CMD_TIMEOUT: cmd timedout

 * @SDW_CMD_FAIL_OTHER: cmd failed due to other reason than above

 *

 * NOTE: The enum is different than actual Spec as response in the Spec is

 * combination of ACK/NAK bits

 *

 * SDW_CMD_TIMEOUT/FAIL_OTHER is defined for SW use, not in spec

 */

enum sdw_command_response {

	SDW_CMD_OK = 0,

	SDW_CMD_IGNORED = 1,

	SDW_CMD_FAIL = 2,

	SDW_CMD_TIMEOUT = 3,

	SDW_CMD_FAIL_OTHER = 4,

};



/*

/*

 * SDW properties, defined in MIPI DisCo spec v1.0

 * SDW properties, defined in MIPI DisCo spec v1.0

 */

 */
@@ -363,12 +384,37 @@ struct sdw_driver { 
 * SDW master structures and APIs

 * SDW master structures and APIs

 */

 */





struct sdw_msg;



/**

 * struct sdw_defer - SDW deffered message

 * @length: message length

 * @complete: message completion

 * @msg: SDW message

 */

struct sdw_defer {

	int length;

	struct completion complete;

	struct sdw_msg *msg;

};



/**

/**

 * struct sdw_master_ops - Master driver ops

 * struct sdw_master_ops - Master driver ops

 * @read_prop: Read Master properties

 * @read_prop: Read Master properties

 * @xfer_msg: Transfer message callback

 * @xfer_msg_defer: Defer version of transfer message callback

 * @reset_page_addr: Reset the SCP page address registers

 */

 */

struct sdw_master_ops {

struct sdw_master_ops {

	int (*read_prop)(struct sdw_bus *bus);

	int (*read_prop)(struct sdw_bus *bus);



	enum sdw_command_response (*xfer_msg)

			(struct sdw_bus *bus, struct sdw_msg *msg);

	enum sdw_command_response (*xfer_msg_defer)

			(struct sdw_bus *bus, struct sdw_msg *msg,

			struct sdw_defer *defer);

	enum sdw_command_response (*reset_page_addr)

			(struct sdw_bus *bus, unsigned int dev_num);

};

};





/**

/**
@@ -379,8 +425,10 @@ struct sdw_master_ops { 
 * @assigned: Bitmap for Slave device numbers.

 * @assigned: Bitmap for Slave device numbers.

 * Bit set implies used number, bit clear implies unused number.

 * Bit set implies used number, bit clear implies unused number.

 * @bus_lock: bus lock

 * @bus_lock: bus lock

 * @msg_lock: message lock

 * @ops: Master callback ops

 * @ops: Master callback ops

 * @prop: Master properties

 * @prop: Master properties

 * @defer_msg: Defer message

 * @clk_stop_timeout: Clock stop timeout computed

 * @clk_stop_timeout: Clock stop timeout computed

 */

 */

struct sdw_bus {

struct sdw_bus {
@@ -389,12 +437,21 @@ struct sdw_bus { 
	struct list_head slaves;

	struct list_head slaves;

	DECLARE_BITMAP(assigned, SDW_MAX_DEVICES);

	DECLARE_BITMAP(assigned, SDW_MAX_DEVICES);

	struct mutex bus_lock;

	struct mutex bus_lock;

	struct mutex msg_lock;

	const struct sdw_master_ops *ops;

	const struct sdw_master_ops *ops;

	struct sdw_master_prop prop;

	struct sdw_master_prop prop;

	struct sdw_defer defer_msg;

	unsigned int clk_stop_timeout;

	unsigned int clk_stop_timeout;

};

};





int sdw_add_bus_master(struct sdw_bus *bus);

int sdw_add_bus_master(struct sdw_bus *bus);

void sdw_delete_bus_master(struct sdw_bus *bus);

void sdw_delete_bus_master(struct sdw_bus *bus);





/* messaging and data APIs */



int sdw_read(struct sdw_slave *slave, u32 addr);

int sdw_write(struct sdw_slave *slave, u32 addr, u8 value);

int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val);

int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val);



#endif /* __SOUNDWIRE_H */
 
#endif /* __SOUNDWIRE_H */