[alsa-devel] [PATCH 06/14] soundwire: Add IO transfer
Vinod Koul
vinod.koul at intel.com
Thu Oct 19 05:03:22 CEST 2017
SoundWire bus supports read and 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 register read/write.
Signed-off-by: Sanyog Kale <sanyog.r.kale at intel.com>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
---
drivers/soundwire/bus.c | 265 ++++++++++++++++++++++++++++++++++++++++++
drivers/soundwire/bus.h | 33 ++++++
include/linux/soundwire/sdw.h | 67 +++++++++++
3 files changed, 365 insertions(+)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 5b13d96b67b8..9ac22eab11bb 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -73,6 +73,12 @@ 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);
@@ -128,6 +134,265 @@ void sdw_delete_bus_master(struct sdw_bus *bus)
}
EXPORT_SYMBOL(sdw_delete_bus_master);
+/*
+ * SDW IO Calls
+ */
+
+static bool sdw_get_page(struct sdw_slave *slave, struct sdw_msg *msg)
+{
+ bool page = false, paging_support = false;
+
+ if (slave && slave->prop.paging_support)
+ paging_support = true;
+
+ /*
+ * Programme SCP page addr for:
+ * 1. addr_page1 and addr_page2 contains non-zero values.
+ * 2. Paging supported by Slave.
+ */
+ switch (msg->dev_num) {
+ case SDW_ENUM_DEV_NUM:
+ case SDW_BROADCAST_DEV_NUM:
+ break;
+
+ default:
+ if (paging_support && ((msg->addr_page1) || (msg->addr_page2)))
+ page = true;
+ }
+
+ return page;
+}
+
+static inline int find_error_code(unsigned int sdw_ret)
+{
+ switch (sdw_ret) {
+ case SDW_CMD_OK:
+ return 0;
+
+ case SDW_CMD_IGNORED:
+ return -ENODATA;
+
+ case SDW_CMD_TIMEOUT:
+ return -ETIMEDOUT;
+ }
+
+ return -EIO;
+}
+
+static inline int do_transfer(struct sdw_bus *bus,
+ struct sdw_msg *msg, bool page)
+{
+ int retry = bus->prop.err_threshold;
+ int ret, i;
+
+ for (ret = 0, i = 0; i <= retry; i++) {
+ ret = bus->ops->xfer_msg(bus, msg, page);
+ ret = find_error_code(ret);
+ /* 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, bool page,
+ struct sdw_defer *defer)
+{
+ int retry = bus->prop.err_threshold;
+ int ret, i;
+
+ defer->msg = msg;
+ defer->length = msg->len;
+
+ for (ret = 0, i = 0; i <= retry; i++) {
+
+ ret = bus->ops->xfer_msg_defer(bus, msg, page, defer);
+ ret = find_error_code(ret);
+ /* 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;
+ int ret, i;
+
+ for (ret = 0, i = 0; i <= retry; i++) {
+ ret = bus->ops->reset_page_addr(bus, dev_num);
+ ret = find_error_code(ret);
+ /* 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
+ * @slave: SDW Slave
+ * @msg: SDW message to be xfered
+ */
+int sdw_transfer(struct sdw_bus *bus, struct sdw_slave *slave,
+ struct sdw_msg *msg)
+{
+ bool page;
+ int ret;
+
+ mutex_lock(&bus->msg_lock);
+
+ page = sdw_get_page(slave, msg);
+
+ ret = do_transfer(bus, msg, page);
+ if (ret != 0 && ret != -ENODATA) {
+ dev_err(bus->dev, "trf on Slave %d failed:%d\n",
+ msg->dev_num, ret);
+ goto error;
+ }
+
+ if (page)
+ ret = sdw_reset_page(bus, msg->dev_num);
+
+error:
+ mutex_unlock(&bus->msg_lock);
+
+ return ret;
+}
+
+/**
+ * sdw_transfer_defer: Asynchronously transfer message to a SDW Slave device
+ *
+ * @bus: SDW bus
+ * @slave: SDW Slave
+ * @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_slave *slave,
+ struct sdw_msg *msg, struct sdw_defer *defer)
+{
+ bool page;
+ int ret;
+
+ if (!bus->ops->xfer_msg_defer)
+ return -ENOTSUPP;
+
+ page = sdw_get_page(slave, msg);
+
+ ret = do_transfer_defer(bus, msg, page, defer);
+ if (ret != 0 && ret != -ENODATA)
+ goto error;
+
+ if (page)
+ ret = sdw_reset_page(bus, msg->dev_num);
+
+error:
+ return ret;
+}
+
+static inline int sdw_fill_msg(struct sdw_msg *msg, u16 addr,
+ size_t count, u16 dev_num, u8 flags, u8 *buf)
+{
+ msg->addr = (addr >> SDW_REG_SHIFT(SDW_REGADDR));
+ msg->len = count;
+ msg->dev_num = dev_num;
+ msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK));
+ msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK));
+ msg->flags = flags;
+ msg->buf = buf;
+ msg->ssp_sync = false;
+
+ 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;
+
+ pm_runtime_get_sync(slave->bus->dev);
+
+ sdw_fill_msg(&msg, addr, count, slave->dev_num, SDW_MSG_FLAG_READ, val);
+ ret = sdw_transfer(slave->bus, slave, &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;
+
+ pm_runtime_get_sync(slave->bus->dev);
+
+ sdw_fill_msg(&msg, addr, count, slave->dev_num, SDW_MSG_FLAG_WRITE, val);
+ ret = sdw_transfer(slave->bus, slave, &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,
unsigned long long addr, struct sdw_slave_id *id)
{
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
index f61bc9f59445..bd3b7d230076 100644
--- a/drivers/soundwire/bus.h
+++ b/drivers/soundwire/bus.h
@@ -79,4 +79,37 @@ int sdw_slave_modalias(struct sdw_slave *slave, char *buf, size_t size);
void sdw_extract_slave_id(struct sdw_bus *bus,
unsigned long long 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)
+ */
+struct sdw_msg {
+ u16 addr;
+ u16 len;
+ u16 dev_num;
+ u8 addr_page1;
+ u8 addr_page2;
+ u8 flags;
+ u8 *buf;
+ bool ssp_sync;
+};
+
+int sdw_transfer(struct sdw_bus *bus, struct sdw_slave *slave,
+ struct sdw_msg *msg);
+int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_slave *slave,
+ struct sdw_msg *msg, struct sdw_defer *defer);
+
#endif /* __SDW_BUS_H */
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index a5bb5e9bc50a..af94c0a29024 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -57,6 +57,14 @@
struct sdw_bus;
struct sdw_slave;
+/* SDW spec defines and enums, as defined by MIPI 1.1. Spec */
+
+/* SDW Broadcast addr */
+#define SDW_BROADCAST_DEV_NUM 15
+
+/* SDW Enumeration Device Number */
+#define SDW_ENUM_DEV_NUM 0
+
#define SDW_MAX_DEVICES 11
/**
@@ -74,6 +82,28 @@ 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 = 4,
+ SDW_CMD_FAIL_OTHER = 8,
+};
+
/*
* SDW properties, defined in MIPI DisCo spec v1.0
*/
@@ -422,13 +452,39 @@ void sdw_unregister_driver(struct sdw_driver *drv);
* 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, int page);
+ enum sdw_command_response (*xfer_msg_defer)
+ (struct sdw_bus *bus, struct sdw_msg *msg,
+ int page, struct sdw_defer *defer);
+ enum sdw_command_response (*reset_page_addr)
+ (struct sdw_bus *bus, unsigned int dev_num);
};
/**
@@ -439,8 +495,10 @@ struct sdw_master_ops {
* @slaves: list of Slaves on this bus
* @assigned: logical addresses assigned, Index 0 (broadcast) would be unused
* @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 {
@@ -449,12 +507,21 @@ struct sdw_bus {
struct list_head slaves;
bool assigned[SDW_MAX_DEVICES + 1];
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 */
--
2.7.4
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