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 Signed-off-by: Vinod Koul vinod.koul@intel.com --- drivers/soundwire/bus.c | 272 ++++++++++++++++++++++++++++++++++++++++++ drivers/soundwire/bus.h | 36 ++++++ include/linux/soundwire/sdw.h | 57 +++++++++ 3 files changed, 365 insertions(+)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 1bed2d33df45..dfa1bd39c8eb 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -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);
@@ -101,6 +109,270 @@ 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) { diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h index a54921825ce0..48eb7de8db7b 100644 --- a/drivers/soundwire/bus.h +++ b/drivers/soundwire/bus.h @@ -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 */ diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index dcadc3e54422..2efc93b1a717 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -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 */ @@ -366,12 +387,37 @@ int sdw_handle_slave_status(struct sdw_bus *bus, * 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); };
/** @@ -382,8 +428,10 @@ 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 { @@ -392,12 +440,21 @@ 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 */