Re: [alsa-devel] [PATCH v4 08/15] soundwire: Add Slave status handling helpers

On 12/1/17 3:56 AM, Vinod Koul wrote:

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 Signed-off-by: Vinod Koul vinod.koul@intel.com

---

drivers/soundwire/bus.c | 202 ++++++++++++++++++++++++++++++++++++++++++ drivers/soundwire/bus.h | 14 +++ include/linux/soundwire/sdw.h | 1 + 3 files changed, 217 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 2f108f162905..09126ddd3cdd 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -372,6 +372,93 @@ 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;
  

My brain is starting to fry but is this correct? Bit11 seems like a valid value. Should it be bit > 15 (assuming bit 12,13,14 are set to avoid using groups and master)?

• }
• /*

• * 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) {

@@ -400,3 +487,118 @@ 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, NULL, &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++;
  

• } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));

explain that the last condition is intentional - this is not a bug -, some devices can drop off during enumeration and rejoin so might be counted twice.

• 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 and parity interrupt mask */
• val = 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 bde5f840ca96..b491e86f2c4c 100644 --- a/drivers/soundwire/bus.h +++ b/drivers/soundwire/bus.h @@ -53,4 +53,18 @@ int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_slave *slave, 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 d3337b5b882b..09619d042909 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -15,6 +15,7 @@ struct sdw_slave; /* SDW Enumeration Device Number */ #define SDW_ENUM_DEV_NUM 0

+#define SDW_NUM_DEV_ID_REGISTERS 6 #define SDW_MAX_DEVICES 11

/**