linux/drivers/soundwire/bus.h
Pierre-Louis Bossart 3ab2ca405a soundwire: bus: add helper to clear Slave status to UNATTACHED
When resuming with a bus reset, we need to re-enumerate and restart
from UNATTACHED. The helper added in this patch helps implement a more
robust state machine avoiding race conditions on resume.

The unattach request is stored and will be used by Slave drivers, if
needed: Intel validation exposed a corner case where the Slave device
may transition to D3 when streaming stops, but streaming restarts
before the Master transitions to D3. In that case, the Slave status
was not cleared as UNATTACHED by the Master resuming, and the
wait_for_completion will time out.

When the slave resumes, it can check if a Master-initiated
re-enumeration and initialization took place and skip the
wait_for_completion() if there is no reason to wait.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-7-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-02-25 15:57:02 +05:30

177 lines
4.8 KiB
C

/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
/* Copyright(c) 2015-17 Intel Corporation. */
#ifndef __SDW_BUS_H
#define __SDW_BUS_H
#define DEFAULT_BANK_SWITCH_TIMEOUT 3000
#define DEFAULT_PROBE_TIMEOUT 2000
#if IS_ENABLED(CONFIG_ACPI)
int sdw_acpi_find_slaves(struct sdw_bus *bus);
#else
static inline int sdw_acpi_find_slaves(struct sdw_bus *bus)
{
return -ENOTSUPP;
}
#endif
int sdw_of_find_slaves(struct sdw_bus *bus);
void sdw_extract_slave_id(struct sdw_bus *bus,
u64 addr, struct sdw_slave_id *id);
#ifdef CONFIG_DEBUG_FS
void sdw_bus_debugfs_init(struct sdw_bus *bus);
void sdw_bus_debugfs_exit(struct sdw_bus *bus);
void sdw_slave_debugfs_init(struct sdw_slave *slave);
void sdw_slave_debugfs_exit(struct sdw_slave *slave);
void sdw_debugfs_init(void);
void sdw_debugfs_exit(void);
#else
static inline void sdw_bus_debugfs_init(struct sdw_bus *bus) {}
static inline void sdw_bus_debugfs_exit(struct sdw_bus *bus) {}
static inline void sdw_slave_debugfs_init(struct sdw_slave *slave) {}
static inline void sdw_slave_debugfs_exit(struct sdw_slave *slave) {}
static inline void sdw_debugfs_init(void) {}
static inline void sdw_debugfs_exit(void) {}
#endif
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;
};
#define SDW_DOUBLE_RATE_FACTOR 2
extern int sdw_rows[SDW_FRAME_ROWS];
extern int sdw_cols[SDW_FRAME_COLS];
int sdw_find_row_index(int row);
int sdw_find_col_index(int col);
/**
* sdw_port_runtime: Runtime port parameters for Master or Slave
*
* @num: Port number. For audio streams, valid port number ranges from
* [1,14]
* @ch_mask: Channel mask
* @transport_params: Transport parameters
* @port_params: Port parameters
* @port_node: List node for Master or Slave port_list
*
* SoundWire spec has no mention of ports for Master interface but the
* concept is logically extended.
*/
struct sdw_port_runtime {
int num;
int ch_mask;
struct sdw_transport_params transport_params;
struct sdw_port_params port_params;
struct list_head port_node;
};
/**
* sdw_slave_runtime: Runtime Stream parameters for Slave
*
* @slave: Slave handle
* @direction: Data direction for Slave
* @ch_count: Number of channels handled by the Slave for
* this stream
* @m_rt_node: sdw_master_runtime list node
* @port_list: List of Slave Ports configured for this stream
*/
struct sdw_slave_runtime {
struct sdw_slave *slave;
enum sdw_data_direction direction;
unsigned int ch_count;
struct list_head m_rt_node;
struct list_head port_list;
};
/**
* sdw_master_runtime: Runtime stream parameters for Master
*
* @bus: Bus handle
* @stream: Stream runtime handle
* @direction: Data direction for Master
* @ch_count: Number of channels handled by the Master for
* this stream, can be zero.
* @slave_rt_list: Slave runtime list
* @port_list: List of Master Ports configured for this stream, can be zero.
* @stream_node: sdw_stream_runtime master_list node
* @bus_node: sdw_bus m_rt_list node
*/
struct sdw_master_runtime {
struct sdw_bus *bus;
struct sdw_stream_runtime *stream;
enum sdw_data_direction direction;
unsigned int ch_count;
struct list_head slave_rt_list;
struct list_head port_list;
struct list_head stream_node;
struct list_head bus_node;
};
struct sdw_dpn_prop *sdw_get_slave_dpn_prop(struct sdw_slave *slave,
enum sdw_data_direction direction,
unsigned int port_num);
int sdw_configure_dpn_intr(struct sdw_slave *slave, int port,
bool enable, int mask);
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);
#define SDW_READ_INTR_CLEAR_RETRY 10
int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf);
/* Read-Modify-Write Slave register */
static inline int
sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
{
int tmp;
tmp = sdw_read(slave, addr);
if (tmp < 0)
return tmp;
tmp = (tmp & ~mask) | val;
return sdw_write(slave, addr, tmp);
}
/*
* At the moment we only track Master-initiated hw_reset.
* Additional fields can be added as needed
*/
#define SDW_UNATTACH_REQUEST_MASTER_RESET BIT(0)
void sdw_clear_slave_status(struct sdw_bus *bus, u32 request);
#endif /* __SDW_BUS_H */