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Subject[PATCH v6 08/14] soundwire: Add Slave status handling helpers
Date
From: Sanyog Kale <sanyog.r.kale@intel.com>

SoundWire Slaves report status to bus. Add helpers to handle
the 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>
---
drivers/soundwire/bus.c | 214 ++++++++++++++++++++++++++++++++++++++++++
drivers/soundwire/bus.h | 14 +++
include/linux/soundwire/sdw.h | 2 +
3 files changed, 230 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index fb9008d6c40e..e306bd4438bd 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -374,6 +374,93 @@ int sdw_write(struct sdw_slave *slave, u32 addr, u8 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)
{
@@ -402,3 +489,130 @@ void sdw_extract_slave_id(struct sdw_bus *bus,
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) |
+ (buf[2] << 24) | ((unsigned long long)buf[1] << 32) |
+ ((unsigned long long)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;
+}
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
index 48eb7de8db7b..e8df55d761c7 100644
--- a/drivers/soundwire/bus.h
+++ b/drivers/soundwire/bus.h
@@ -52,4 +52,18 @@ int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf);

+/* Read-Modify-Write Slave register */
+static inline int
+sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
+{
+ int tmp;
+
+ tmp = sdw_read(slave, addr);
+ if (tmp < 0)
+ return tmp;
+
+ tmp = (tmp & ~mask) | val;
+ return sdw_write(slave, addr, tmp);
+}
+
#endif /* __SDW_BUS_H */
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index d4fa95efe8cd..cbadddce470d 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -22,6 +22,8 @@ struct sdw_slave;
/* SDW Master Device Number, not supported yet */
#define SDW_MASTER_DEV_NUM 14

+#define SDW_NUM_DEV_ID_REGISTERS 6
+
#define SDW_MAX_DEVICES 11

/**
--
2.7.4
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