diff options
Diffstat (limited to 'drivers/soundwire/bus.c')
| -rw-r--r-- | drivers/soundwire/bus.c | 1042 |
1 files changed, 1042 insertions, 0 deletions
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c new file mode 100644 index 000000000..0089b606b --- /dev/null +++ b/drivers/soundwire/bus.c @@ -0,0 +1,1042 @@ +// 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"); + 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); + INIT_LIST_HEAD(&bus->m_rt_list); + + 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; + } + + /* + * Initialize clock values based on Master properties. The max + * frequency is read from max_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_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; + + 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; + 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; + 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; + 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); + + found = false; + /* 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); +} + +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", 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", 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] = {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); + + /* 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); |