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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: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vinod Koul 2017-12-14 11:19:37 +05:30 committed by Greg Kroah-Hartman
parent 6f3da1f388
commit 9d715fa005
3 changed files with 365 additions and 0 deletions
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272
drivers/soundwire/bus.c
View File

@ -3,6 +3,8 @@
#include <linux/acpi.h>
#include <linux/mod_devicetable.h>
#include <linux/pm_runtime.h>
#include <linux/soundwire/sdw_registers.h>
#include <linux/soundwire/sdw.h>
#include "bus.h"
@ -22,6 +24,12 @@ int sdw_add_bus_master(struct sdw_bus *bus)
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);
INIT_LIST_HEAD(&bus->slaves);
@ -102,6 +110,270 @@ void sdw_delete_bus_master(struct sdw_bus *bus)
}
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,
u64 addr, struct sdw_slave_id *id)
{

36
drivers/soundwire/bus.h
View File

@ -16,4 +16,40 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus)
void sdw_extract_slave_id(struct sdw_bus *bus,
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 */

57
include/linux/soundwire/sdw.h
View File

@ -38,6 +38,27 @@ enum sdw_slave_status {
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
*/
@ -363,12 +384,37 @@ struct sdw_driver {
* 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
* @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 {
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.
* Bit set implies used number, bit clear implies unused number.
* @bus_lock: bus lock
* @msg_lock: message lock
* @ops: Master callback ops
* @prop: Master properties
* @defer_msg: Defer message
* @clk_stop_timeout: Clock stop timeout computed
*/
struct sdw_bus {
@ -389,12 +437,21 @@ struct sdw_bus {
struct list_head slaves;
DECLARE_BITMAP(assigned, SDW_MAX_DEVICES);
struct mutex bus_lock;
struct mutex msg_lock;
const struct sdw_master_ops *ops;
struct sdw_master_prop prop;
struct sdw_defer defer_msg;
unsigned int clk_stop_timeout;
};
int sdw_add_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 */