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path: root/drivers/soundwire/bus.c
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-rw-r--r--drivers/soundwire/bus.c997
1 files changed, 997 insertions, 0 deletions
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
new file mode 100644
index 000000000000..d6dc8e7a8614
--- /dev/null
+++ b/drivers/soundwire/bus.c
@@ -0,0 +1,997 @@
+// 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);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 00:06:49 +0000