linux/drivers/soundwire/bus.c

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// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
// Copyright(c) 2015-17 Intel Corporation.
#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"
/**
* sdw_add_bus_master() - add a bus Master instance
* @bus: bus instance
*
* Initializes the bus instance, read properties and create child
* devices.
*/
int sdw_add_bus_master(struct sdw_bus *bus)
{
int ret;
if (!bus->dev) {
pr_err("SoundWire bus has no device");
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);
if (bus->ops->read_prop) {
ret = bus->ops->read_prop(bus);
if (ret < 0) {
dev_err(bus->dev, "Bus read properties failed:%d", ret);
return ret;
}
}
/*
* Device numbers in SoundWire are 0 thru 15. Enumeration device
* number (0), Broadcast device number (15), Group numbers (12 and
* 13) and Master device number (14) are not used for assignment so
* mask these and other higher bits.
*/
/* Set higher order bits */
*bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
/* Set enumuration device number and broadcast device number */
set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
/* Set group device numbers and master device number */
set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
/*
* SDW is an enumerable bus, but devices can be powered off. So,
* they won't be able to report as present.
*
* Create Slave devices based on Slaves described in
* the respective firmware (ACPI/DT)
*/
if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
ret = sdw_acpi_find_slaves(bus);
else
ret = -ENOTSUPP; /* No ACPI/DT so error out */
if (ret) {
dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
return ret;
}
return 0;
}
EXPORT_SYMBOL(sdw_add_bus_master);
static int sdw_delete_slave(struct device *dev, void *data)
{
struct sdw_slave *slave = dev_to_sdw_dev(dev);
struct sdw_bus *bus = slave->bus;
mutex_lock(&bus->bus_lock);
if (slave->dev_num) /* clear dev_num if assigned */
clear_bit(slave->dev_num, bus->assigned);
list_del_init(&slave->node);
mutex_unlock(&bus->bus_lock);
device_unregister(dev);
return 0;
}
/**
* sdw_delete_bus_master() - delete the bus master instance
* @bus: bus to be deleted
*
* Remove the instance, delete the child devices.
*/
void sdw_delete_bus_master(struct sdw_bus *bus)
{
device_for_each_child(bus->dev, NULL, sdw_delete_slave);
}
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 < 0)
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 < 0)
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);
/*
* SDW alert handling
*/
/* called with bus_lock held */
static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
{
struct sdw_slave *slave = NULL;
list_for_each_entry(slave, &bus->slaves, node) {
if (slave->dev_num == i)
return slave;
}
return NULL;
}
static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
{
if ((slave->id.unique_id != id.unique_id) ||
(slave->id.mfg_id != id.mfg_id) ||
(slave->id.part_id != id.part_id) ||
(slave->id.class_id != id.class_id))
return -ENODEV;
return 0;
}
/* called with bus_lock held */
static int sdw_get_device_num(struct sdw_slave *slave)
{
int bit;
bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
if (bit == SDW_MAX_DEVICES) {
bit = -ENODEV;
goto err;
}
/*
* Do not update dev_num in Slave data structure here,
* Update once program dev_num is successful
*/
set_bit(bit, slave->bus->assigned);
err:
return bit;
}
static int sdw_assign_device_num(struct sdw_slave *slave)
{
int ret, dev_num;
/* check first if device number is assigned, if so reuse that */
if (!slave->dev_num) {
mutex_lock(&slave->bus->bus_lock);
dev_num = sdw_get_device_num(slave);
mutex_unlock(&slave->bus->bus_lock);
if (dev_num < 0) {
dev_err(slave->bus->dev, "Get dev_num failed: %d",
dev_num);
return dev_num;
}
} else {
dev_info(slave->bus->dev,
"Slave already registered dev_num:%d",
slave->dev_num);
/* Clear the slave->dev_num to transfer message on device 0 */
dev_num = slave->dev_num;
slave->dev_num = 0;
}
ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);
if (ret < 0) {
dev_err(&slave->dev, "Program device_num failed: %d", ret);
return ret;
}
/* After xfer of msg, restore dev_num */
slave->dev_num = dev_num;
return 0;
}
void sdw_extract_slave_id(struct sdw_bus *bus,
u64 addr, struct sdw_slave_id *id)
{
dev_dbg(bus->dev, "SDW Slave Addr: %llx", addr);
/*
* Spec definition
* Register Bit Contents
* DevId_0 [7:4] 47:44 sdw_version
* DevId_0 [3:0] 43:40 unique_id
* DevId_1 39:32 mfg_id [15:8]
* DevId_2 31:24 mfg_id [7:0]
* DevId_3 23:16 part_id [15:8]
* DevId_4 15:08 part_id [7:0]
* DevId_5 07:00 class_id
*/
id->sdw_version = (addr >> 44) & GENMASK(3, 0);
id->unique_id = (addr >> 40) & GENMASK(3, 0);
id->mfg_id = (addr >> 24) & GENMASK(15, 0);
id->part_id = (addr >> 8) & GENMASK(15, 0);
id->class_id = addr & GENMASK(7, 0);
dev_dbg(bus->dev,
"SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x",
id->class_id, id->part_id, id->mfg_id,
id->unique_id, id->sdw_version);
}
static int sdw_program_device_num(struct sdw_bus *bus)
{
u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
struct sdw_slave *slave, *_s;
struct sdw_slave_id id;
struct sdw_msg msg;
bool found = false;
int count = 0, ret;
u64 addr;
/* No Slave, so use raw xfer api */
ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
if (ret < 0)
return ret;
do {
ret = sdw_transfer(bus, &msg);
if (ret == -ENODATA) { /* end of device id reads */
ret = 0;
break;
}
if (ret < 0) {
dev_err(bus->dev, "DEVID read fail:%d\n", ret);
break;
}
/*
* Construct the addr and extract. Cast the higher shift
* bits to avoid truncation due to size limit.
*/
addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
((u64)buf[0] << 40);
sdw_extract_slave_id(bus, addr, &id);
/* Now compare with entries */
list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
if (sdw_compare_devid(slave, id) == 0) {
found = true;
/*
* Assign a new dev_num to this Slave and
* not mark it present. It will be marked
* present after it reports ATTACHED on new
* dev_num
*/
ret = sdw_assign_device_num(slave);
if (ret) {
dev_err(slave->bus->dev,
"Assign dev_num failed:%d",
ret);
return ret;
}
break;
}
}
if (found == false) {
/* TODO: Park this device in Group 13 */
dev_err(bus->dev, "Slave Entry not found");
}
count++;
/*
* Check till error out or retry (count) exhausts.
* Device can drop off and rejoin during enumeration
* so count till twice the bound.
*/
} while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
return ret;
}
static void sdw_modify_slave_status(struct sdw_slave *slave,
enum sdw_slave_status status)
{
mutex_lock(&slave->bus->bus_lock);
slave->status = status;
mutex_unlock(&slave->bus->bus_lock);
}
static int sdw_initialize_slave(struct sdw_slave *slave)
{
struct sdw_slave_prop *prop = &slave->prop;
int ret;
u8 val;
/*
* Set bus clash, parity and SCP implementation
* defined interrupt mask
* TODO: Read implementation defined interrupt mask
* from Slave property
*/
val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH |
SDW_SCP_INT1_PARITY;
/* Enable SCP interrupts */
ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INTMASK1 write failed:%d", ret);
return ret;
}
/* No need to continue if DP0 is not present */
if (!slave->prop.dp0_prop)
return 0;
/* Enable DP0 interrupts */
val = prop->dp0_prop->device_interrupts;
val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_DP0_INTMASK read failed:%d", ret);
return val;
}
return 0;
}
static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
{
u8 clear = 0, impl_int_mask;
int status, status2, ret, count = 0;
status = sdw_read(slave, SDW_DP0_INT);
if (status < 0) {
dev_err(slave->bus->dev,
"SDW_DP0_INT read failed:%d", status);
return status;
}
do {
if (status & SDW_DP0_INT_TEST_FAIL) {
dev_err(&slave->dev, "Test fail for port 0");
clear |= SDW_DP0_INT_TEST_FAIL;
}
/*
* Assumption: PORT_READY interrupt will be received only for
* ports implementing Channel Prepare state machine (CP_SM)
*/
if (status & SDW_DP0_INT_PORT_READY) {
complete(&slave->port_ready[0]);
clear |= SDW_DP0_INT_PORT_READY;
}
if (status & SDW_DP0_INT_BRA_FAILURE) {
dev_err(&slave->dev, "BRA failed");
clear |= SDW_DP0_INT_BRA_FAILURE;
}
impl_int_mask = SDW_DP0_INT_IMPDEF1 |
SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
if (status & impl_int_mask) {
clear |= impl_int_mask;
*slave_status = clear;
}
/* clear the interrupt */
ret = sdw_write(slave, SDW_DP0_INT, clear);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_DP0_INT write failed:%d", ret);
return ret;
}
/* Read DP0 interrupt again */
status2 = sdw_read(slave, SDW_DP0_INT);
if (status2 < 0) {
dev_err(slave->bus->dev,
"SDW_DP0_INT read failed:%d", status2);
return status2;
}
status &= status2;
count++;
/* we can get alerts while processing so keep retrying */
} while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
if (count == SDW_READ_INTR_CLEAR_RETRY)
dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read");
return ret;
}
static int sdw_handle_port_interrupt(struct sdw_slave *slave,
int port, u8 *slave_status)
{
u8 clear = 0, impl_int_mask;
int status, status2, ret, count = 0;
u32 addr;
if (port == 0)
return sdw_handle_dp0_interrupt(slave, slave_status);
addr = SDW_DPN_INT(port);
status = sdw_read(slave, addr);
if (status < 0) {
dev_err(slave->bus->dev,
"SDW_DPN_INT read failed:%d", status);
return status;
}
do {
if (status & SDW_DPN_INT_TEST_FAIL) {
dev_err(&slave->dev, "Test fail for port:%d", port);
clear |= SDW_DPN_INT_TEST_FAIL;
}
/*
* Assumption: PORT_READY interrupt will be received only
* for ports implementing CP_SM.
*/
if (status & SDW_DPN_INT_PORT_READY) {
complete(&slave->port_ready[port]);
clear |= SDW_DPN_INT_PORT_READY;
}
impl_int_mask = SDW_DPN_INT_IMPDEF1 |
SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
if (status & impl_int_mask) {
clear |= impl_int_mask;
*slave_status = clear;
}
/* clear the interrupt */
ret = sdw_write(slave, addr, clear);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_DPN_INT write failed:%d", ret);
return ret;
}
/* Read DPN interrupt again */
status2 = sdw_read(slave, addr);
if (status2 < 0) {
dev_err(slave->bus->dev,
"SDW_DPN_INT read failed:%d", status2);
return status2;
}
status &= status2;
count++;
/* we can get alerts while processing so keep retrying */
} while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
if (count == SDW_READ_INTR_CLEAR_RETRY)
dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read");
return ret;
}
static int sdw_handle_slave_alerts(struct sdw_slave *slave)
{
struct sdw_slave_intr_status slave_intr;
u8 clear = 0, bit, port_status[15];
int port_num, stat, ret, count = 0;
unsigned long port;
bool slave_notify = false;
u8 buf, buf2[2], _buf, _buf2[2];
sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
/* Read Instat 1, Instat 2 and Instat 3 registers */
buf = ret = sdw_read(slave, SDW_SCP_INT1);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 read failed:%d", ret);
return ret;
}
ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT2/3 read failed:%d", ret);
return ret;
}
do {
/*
* Check parity, bus clash and Slave (impl defined)
* interrupt
*/
if (buf & SDW_SCP_INT1_PARITY) {
dev_err(&slave->dev, "Parity error detected");
clear |= SDW_SCP_INT1_PARITY;
}
if (buf & SDW_SCP_INT1_BUS_CLASH) {
dev_err(&slave->dev, "Bus clash error detected");
clear |= SDW_SCP_INT1_BUS_CLASH;
}
/*
* When bus clash or parity errors are detected, such errors
* are unlikely to be recoverable errors.
* TODO: In such scenario, reset bus. Make this configurable
* via sysfs property with bus reset being the default.
*/
if (buf & SDW_SCP_INT1_IMPL_DEF) {
dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
clear |= SDW_SCP_INT1_IMPL_DEF;
slave_notify = true;
}
/* Check port 0 - 3 interrupts */
port = buf & SDW_SCP_INT1_PORT0_3;
/* To get port number corresponding to bits, shift it */
port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3);
for_each_set_bit(bit, &port, 8) {
sdw_handle_port_interrupt(slave, bit,
&port_status[bit]);
}
/* Check if cascade 2 interrupt is present */
if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
for_each_set_bit(bit, &port, 8) {
/* scp2 ports start from 4 */
port_num = bit + 3;
sdw_handle_port_interrupt(slave,
port_num,
&port_status[port_num]);
}
}
/* now check last cascade */
if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
for_each_set_bit(bit, &port, 8) {
/* scp3 ports start from 11 */
port_num = bit + 10;
sdw_handle_port_interrupt(slave,
port_num,
&port_status[port_num]);
}
}
/* Update the Slave driver */
if (slave_notify && (slave->ops) &&
(slave->ops->interrupt_callback)) {
slave_intr.control_port = clear;
memcpy(slave_intr.port, &port_status,
sizeof(slave_intr.port));
slave->ops->interrupt_callback(slave, &slave_intr);
}
/* Ack interrupt */
ret = sdw_write(slave, SDW_SCP_INT1, clear);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 write failed:%d", ret);
return ret;
}
/*
* Read status again to ensure no new interrupts arrived
* while servicing interrupts.
*/
_buf = ret = sdw_read(slave, SDW_SCP_INT1);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 read failed:%d", ret);
return ret;
}
ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT2/3 read failed:%d", ret);
return ret;
}
/* Make sure no interrupts are pending */
buf &= _buf;
buf2[0] &= _buf2[0];
buf2[1] &= _buf2[1];
stat = buf || buf2[0] || buf2[1];
/*
* Exit loop if Slave is continuously in ALERT state even
* after servicing the interrupt multiple times.
*/
count++;
/* we can get alerts while processing so keep retrying */
} while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
if (count == SDW_READ_INTR_CLEAR_RETRY)
dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read");
return ret;
}
static int sdw_update_slave_status(struct sdw_slave *slave,
enum sdw_slave_status status)
{
if ((slave->ops) && (slave->ops->update_status))
return slave->ops->update_status(slave, status);
return 0;
}
/**
* sdw_handle_slave_status() - Handle Slave status
* @bus: SDW bus instance
* @status: Status for all Slave(s)
*/
int sdw_handle_slave_status(struct sdw_bus *bus,
enum sdw_slave_status status[])
{
enum sdw_slave_status prev_status;
struct sdw_slave *slave;
int i, ret = 0;
if (status[0] == SDW_SLAVE_ATTACHED) {
ret = sdw_program_device_num(bus);
if (ret)
dev_err(bus->dev, "Slave attach failed: %d", ret);
}
/* Continue to check other slave statuses */
for (i = 1; i <= SDW_MAX_DEVICES; i++) {
mutex_lock(&bus->bus_lock);
if (test_bit(i, bus->assigned) == false) {
mutex_unlock(&bus->bus_lock);
continue;
}
mutex_unlock(&bus->bus_lock);
slave = sdw_get_slave(bus, i);
if (!slave)
continue;
switch (status[i]) {
case SDW_SLAVE_UNATTACHED:
if (slave->status == SDW_SLAVE_UNATTACHED)
break;
sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
break;
case SDW_SLAVE_ALERT:
ret = sdw_handle_slave_alerts(slave);
if (ret)
dev_err(bus->dev,
"Slave %d alert handling failed: %d",
i, ret);
break;
case SDW_SLAVE_ATTACHED:
if (slave->status == SDW_SLAVE_ATTACHED)
break;
prev_status = slave->status;
sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
if (prev_status == SDW_SLAVE_ALERT)
break;
ret = sdw_initialize_slave(slave);
if (ret)
dev_err(bus->dev,
"Slave %d initialization failed: %d",
i, ret);
break;
default:
dev_err(bus->dev, "Invalid slave %d status:%d",
i, status[i]);
break;
}
ret = sdw_update_slave_status(slave, status[i]);
if (ret)
dev_err(slave->bus->dev,
"Update Slave status failed:%d", ret);
}
return ret;
}
EXPORT_SYMBOL(sdw_handle_slave_status);