soundwire: Add slave status handling
authorVinod Koul <vinod.koul@intel.com>
Thu, 14 Dec 2017 05:49:40 +0000 (11:19 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 19 Dec 2017 10:28:13 +0000 (11:28 +0100)
Add status handling API sdw_handle_slave_status() to handle
Slave status changes.

Signed-off-by: Hardik T Shah <hardik.t.shah@intel.com>
Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/soundwire/bus.c
drivers/soundwire/bus.h
include/linux/soundwire/sdw.h

index e306bd4..4c34519 100644 (file)
@@ -616,3 +616,382 @@ static int sdw_initialize_slave(struct sdw_slave *slave)
 
        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", status);
+                       return status;
+               }
+               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 (status < 0) {
+                       dev_err(slave->bus->dev,
+                                       "SDW_DPN_INT read failed:%d", status);
+                       return status;
+               }
+               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 */
+       ret = buf = 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.
+                */
+               ret = _buf = 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);
index e8df55d..345c34d 100644 (file)
@@ -49,6 +49,8 @@ int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg);
 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
                                struct sdw_defer *defer);
 
+#define SDW_READ_INTR_CLEAR_RETRY      10
+
 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
                u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf);
 
index cbadddc..e91fdcf 100644 (file)
@@ -331,11 +331,28 @@ struct sdw_slave_id {
 };
 
 /**
+ * struct sdw_slave_intr_status - Slave interrupt status
+ * @control_port: control port status
+ * @port: data port status
+ */
+struct sdw_slave_intr_status {
+       u8 control_port;
+       u8 port[15];
+};
+
+/**
  * struct sdw_slave_ops - Slave driver callback ops
  * @read_prop: Read Slave properties
+ * @interrupt_callback: Device interrupt notification (invoked in thread
+ * context)
+ * @update_status: Update Slave status
  */
 struct sdw_slave_ops {
        int (*read_prop)(struct sdw_slave *sdw);
+       int (*interrupt_callback)(struct sdw_slave *slave,
+                       struct sdw_slave_intr_status *status);
+       int (*update_status)(struct sdw_slave *slave,
+                       enum sdw_slave_status status);
 };
 
 /**
@@ -382,6 +399,9 @@ struct sdw_driver {
        { .mfg_id = (_mfg_id), .part_id = (_part_id), \
          .driver_data = (unsigned long)(_drv_data) }
 
+int sdw_handle_slave_status(struct sdw_bus *bus,
+                       enum sdw_slave_status status[]);
+
 /*
  * SDW master structures and APIs
  */