linux_dsm_epyc7002/drivers/soundwire/bus.c
Rander Wang aa79293517 soundwire: bus: fix io error when processing alert event
There are two types of io errors when processing alert event.

a) the Master detects an ALERT status for e.g. a jack event and
invokes the implementation-defined function in the Slave driver to
check the jack status. At this time the codec is just suspended, so io
registers can't be accessed.

b) when waking up from clock stop mode1 state, where the bus needs a
complete re-enumeration, Slave registers can't be accessed until the
enumeration is complete.

This patch resumes the Slave device and waits for initialization
complete when processing slave alert event, so that registers on the
Slave can be accessed without timeouts or io errors.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-9-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-02-25 15:57:02 +05:30

1206 lines
28 KiB
C

// 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)
{
struct sdw_master_prop *prop = NULL;
int ret;
if (!bus->dev) {
pr_err("SoundWire bus has no device\n");
return -ENODEV;
}
if (!bus->ops) {
dev_err(bus->dev, "SoundWire Bus ops are not set\n");
return -EINVAL;
}
mutex_init(&bus->msg_lock);
mutex_init(&bus->bus_lock);
INIT_LIST_HEAD(&bus->slaves);
INIT_LIST_HEAD(&bus->m_rt_list);
/*
* Initialize multi_link flag
* TODO: populate this flag by reading property from FW node
*/
bus->multi_link = false;
if (bus->ops->read_prop) {
ret = bus->ops->read_prop(bus);
if (ret < 0) {
dev_err(bus->dev,
"Bus read properties failed:%d\n", ret);
return ret;
}
}
sdw_bus_debugfs_init(bus);
/*
* Device numbers in SoundWire are 0 through 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 if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)
ret = sdw_of_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;
}
/*
* Initialize clock values based on Master properties. The max
* frequency is read from max_clk_freq property. Current assumption
* is that the bus will start at highest clock frequency when
* powered on.
*
* Default active bank will be 0 as out of reset the Slaves have
* to start with bank 0 (Table 40 of Spec)
*/
prop = &bus->prop;
bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR;
bus->params.curr_dr_freq = bus->params.max_dr_freq;
bus->params.curr_bank = SDW_BANK0;
bus->params.next_bank = SDW_BANK1;
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;
pm_runtime_disable(dev);
sdw_slave_debugfs_exit(slave);
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);
sdw_bus_debugfs_exit(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;
init_completion(&defer->complete);
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;
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-through 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\n", 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;
}
/*
* Read/Write IO functions.
* no_pm versions can only be called by the bus, e.g. while enumerating or
* handling suspend-resume sequences.
* all clients need to use the pm versions
*/
static int
sdw_nread_no_pm(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;
return sdw_transfer(slave->bus, &msg);
}
static int
sdw_nwrite_no_pm(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;
return sdw_transfer(slave->bus, &msg);
}
static int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
{
return sdw_nwrite_no_pm(slave, addr, 1, &value);
}
/**
* 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)
{
int ret;
ret = pm_runtime_get_sync(slave->bus->dev);
if (ret < 0 && ret != -EACCES) {
pm_runtime_put_noidle(slave->bus->dev);
return ret;
}
ret = sdw_nread_no_pm(slave, addr, count, val);
pm_runtime_mark_last_busy(slave->bus->dev);
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)
{
int ret;
ret = pm_runtime_get_sync(slave->bus->dev);
if (ret < 0 && ret != -EACCES) {
pm_runtime_put_noidle(slave->bus->dev);
return ret;
}
ret = sdw_nwrite_no_pm(slave, addr, count, val);
pm_runtime_mark_last_busy(slave->bus->dev);
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.mfg_id != id.mfg_id ||
slave->id.part_id != id.part_id ||
slave->id.class_id != id.class_id ||
(slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
slave->id.unique_id != id.unique_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;
bool new_device = false;
/* check first if device number is assigned, if so reuse that */
if (!slave->dev_num) {
if (!slave->dev_num_sticky) {
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\n",
dev_num);
return dev_num;
}
slave->dev_num = dev_num;
slave->dev_num_sticky = dev_num;
new_device = true;
} else {
slave->dev_num = slave->dev_num_sticky;
}
}
if (!new_device)
dev_info(slave->bus->dev,
"Slave already registered, reusing dev_num:%d\n",
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_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
if (ret < 0) {
dev_err(&slave->dev, "Program device_num %d failed: %d\n",
dev_num, ret);
return ret;
}
/* After xfer of msg, restore dev_num */
slave->dev_num = slave->dev_num_sticky;
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\n", 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\n",
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 */
dev_dbg(bus->dev, "No more devices to enumerate\n");
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\n",
ret);
return ret;
}
break;
}
}
if (!found) {
/* TODO: Park this device in Group 13 */
dev_err(bus->dev, "Slave Entry not found\n");
}
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);
dev_vdbg(&slave->dev,
"%s: changing status slave %d status %d new status %d\n",
__func__, slave->dev_num, slave->status, status);
if (status == SDW_SLAVE_UNATTACHED) {
dev_dbg(&slave->dev,
"%s: initializing completion for Slave %d\n",
__func__, slave->dev_num);
init_completion(&slave->enumeration_complete);
init_completion(&slave->initialization_complete);
} else if ((status == SDW_SLAVE_ATTACHED) &&
(slave->status == SDW_SLAVE_UNATTACHED)) {
dev_dbg(&slave->dev,
"%s: signaling completion for Slave %d\n",
__func__, slave->dev_num);
complete(&slave->enumeration_complete);
}
slave->status = status;
mutex_unlock(&slave->bus->bus_lock);
}
int sdw_configure_dpn_intr(struct sdw_slave *slave,
int port, bool enable, int mask)
{
u32 addr;
int ret;
u8 val = 0;
addr = SDW_DPN_INTMASK(port);
/* Set/Clear port ready interrupt mask */
if (enable) {
val |= mask;
val |= SDW_DPN_INT_PORT_READY;
} else {
val &= ~(mask);
val &= ~SDW_DPN_INT_PORT_READY;
}
ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
if (ret < 0)
dev_err(slave->bus->dev,
"SDW_DPN_INTMASK write failed:%d\n", val);
return ret;
}
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\n", 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->imp_def_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\n", 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\n", status);
return status;
}
do {
if (status & SDW_DP0_INT_TEST_FAIL) {
dev_err(&slave->dev, "Test fail for port 0\n");
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\n");
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\n", 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\n", 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\n");
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\n", status);
return status;
}
do {
if (status & SDW_DPN_INT_TEST_FAIL) {
dev_err(&slave->dev, "Test fail for port:%d\n", 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\n", 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\n", 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] = {0};
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);
ret = pm_runtime_get_sync(&slave->dev);
if (ret < 0 && ret != -EACCES) {
dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
pm_runtime_put_noidle(slave->bus->dev);
return ret;
}
/* Read Instat 1, Instat 2 and Instat 3 registers */
ret = sdw_read(slave, SDW_SCP_INT1);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 read failed:%d\n", ret);
goto io_err;
}
buf = 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\n", ret);
goto io_err;
}
do {
/*
* Check parity, bus clash and Slave (impl defined)
* interrupt
*/
if (buf & SDW_SCP_INT1_PARITY) {
dev_err(&slave->dev, "Parity error detected\n");
clear |= SDW_SCP_INT1_PARITY;
}
if (buf & SDW_SCP_INT1_BUS_CLASH) {
dev_err(&slave->dev, "Bus clash error detected\n");
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\n", ret);
goto io_err;
}
/*
* Read status again to ensure no new interrupts arrived
* while servicing interrupts.
*/
ret = sdw_read(slave, SDW_SCP_INT1);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 read failed:%d\n", ret);
goto io_err;
}
_buf = 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\n", ret);
goto io_err;
}
/* 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\n");
io_err:
pm_runtime_mark_last_busy(&slave->dev);
pm_runtime_put_autosuspend(&slave->dev);
return ret;
}
static int sdw_update_slave_status(struct sdw_slave *slave,
enum sdw_slave_status status)
{
unsigned long time;
if (!slave->probed) {
/*
* the slave status update is typically handled in an
* interrupt thread, which can race with the driver
* probe, e.g. when a module needs to be loaded.
*
* make sure the probe is complete before updating
* status.
*/
time = wait_for_completion_timeout(&slave->probe_complete,
msecs_to_jiffies(DEFAULT_PROBE_TIMEOUT));
if (!time) {
dev_err(&slave->dev, "Probe not complete, timed out\n");
return -ETIMEDOUT;
}
}
if (!slave->ops || !slave->ops->update_status)
return 0;
return slave->ops->update_status(slave, status);
}
/**
* 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;
bool attached_initializing;
int i, ret = 0;
/* first check if any Slaves fell off the bus */
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;
if (status[i] == SDW_SLAVE_UNATTACHED &&
slave->status != SDW_SLAVE_UNATTACHED)
sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
}
if (status[0] == SDW_SLAVE_ATTACHED) {
dev_dbg(bus->dev, "Slave attached, programming device number\n");
ret = sdw_program_device_num(bus);
if (ret)
dev_err(bus->dev, "Slave attach failed: %d\n", ret);
/*
* programming a device number will have side effects,
* so we deal with other devices at a later time
*/
return 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;
attached_initializing = false;
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\n",
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;
attached_initializing = true;
ret = sdw_initialize_slave(slave);
if (ret)
dev_err(bus->dev,
"Slave %d initialization failed: %d\n",
i, ret);
break;
default:
dev_err(bus->dev, "Invalid slave %d status:%d\n",
i, status[i]);
break;
}
ret = sdw_update_slave_status(slave, status[i]);
if (ret)
dev_err(slave->bus->dev,
"Update Slave status failed:%d\n", ret);
if (attached_initializing)
complete(&slave->initialization_complete);
}
return ret;
}
EXPORT_SYMBOL(sdw_handle_slave_status);
void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
{
struct sdw_slave *slave;
int i;
/* Check all non-zero devices */
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;
if (slave->status != SDW_SLAVE_UNATTACHED)
sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
/* keep track of request, used in pm_runtime resume */
slave->unattach_request = request;
}
}
EXPORT_SYMBOL(sdw_clear_slave_status);