bif: bif-core: add auto task triggering support
Add support in the bif-core driver for enabling and disabling
automatic task triggering for specified tasks. One example of
auto task triggering is the periodic polling method employed by
the BIF slave temperature function to check for high or low
temperature conditions.
Change-Id: If01071debd430c084be344549ecf2e8b281d4e05
Signed-off-by: David Collins <collinsd@codeaurora.org>
diff --git a/Documentation/bif-framework.txt b/Documentation/bif-framework.txt
index 3ba500d..4c9f215 100644
--- a/Documentation/bif-framework.txt
+++ b/Documentation/bif-framework.txt
@@ -341,11 +341,17 @@
int bif_task_is_busy(struct bif_slave *slave, unsigned int task);
+int bif_enable_auto_task(struct bif_slave *slave, unsigned int task);
+
+int bif_disable_auto_task(struct bif_slave *slave, unsigned int task);
+
A consumer can request a slave interrupt and specify a notifier to call when the
interrupt is triggered. Once the interrupt is requested the consumer will need
to call bif_trigger_task() in order to start the task associated with the
interrupt (both are identified by the same index). Polling for task completion
-is also supported via the bif_task_is_busy() function.
+is also supported via the bif_task_is_busy() function. Auto task triggered can
+be enabled and disabled for a given task using bif_enable_auto_task() and
+bif_disable_auto_task() respectively.
Raw BIF bus transactions:
-------------------------
diff --git a/drivers/bif/bif-core.c b/drivers/bif/bif-core.c
index 3d51b3c..2cd9c98 100644
--- a/drivers/bif/bif-core.c
+++ b/drivers/bif/bif-core.c
@@ -577,6 +577,133 @@
return rc;
}
+/* Perform a read-modify-write sequence on a single BIF slave register. */
+static int _bif_slave_masked_write(struct bif_slave_dev *sdev, u16 addr, u8 val,
+ u8 mask)
+{
+ int rc;
+ u8 reg;
+
+ rc = _bif_slave_read(sdev, addr, ®, 1);
+ if (rc)
+ return rc;
+
+ reg = (reg & ~mask) | (val & mask);
+
+ return _bif_slave_write(sdev, addr, ®, 1);
+}
+
+static int _bif_check_task(struct bif_slave_dev *sdev, unsigned int task)
+{
+ if (IS_ERR_OR_NULL(sdev)) {
+ pr_err("Invalid slave device handle=%ld\n", PTR_ERR(sdev));
+ return -EINVAL;
+ } else if (!sdev->bdev) {
+ pr_err("BIF controller has been removed\n");
+ return -ENXIO;
+ } else if (!sdev->slave_ctrl_function
+ || sdev->slave_ctrl_function->task_count == 0) {
+ pr_err("BIF slave does not support slave control\n");
+ return -ENODEV;
+ } else if (task >= sdev->slave_ctrl_function->task_count) {
+ pr_err("Requested task: %u greater than max: %u for this slave\n",
+ task, sdev->slave_ctrl_function->task_count);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int _bif_task_is_busy(struct bif_slave_dev *sdev, unsigned int task)
+{
+ int rc;
+ u16 addr;
+ u8 reg = 0;
+
+ rc = _bif_check_task(sdev, task);
+ if (rc) {
+ pr_err("Invalid slave device or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Check the task busy state. */
+ addr = SLAVE_CTRL_FUNC_TASK_BUSY_ADDR(
+ sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ rc = _bif_slave_read(sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ return (reg & BIT(task % SLAVE_CTRL_TASKS_PER_SET)) ? 1 : 0;
+}
+
+static int _bif_enable_auto_task(struct bif_slave_dev *sdev, unsigned int task)
+{
+ int rc;
+ u16 addr;
+ u8 mask;
+
+ rc = _bif_check_task(sdev, task);
+ if (rc) {
+ pr_err("Invalid slave device or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Enable the auto task within the slave */
+ mask = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+ addr = SLAVE_CTRL_FUNC_TASK_AUTO_TRIGGER_ADDR(
+ sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ if (task / SLAVE_CTRL_TASKS_PER_SET == 0) {
+ /* Set global auto task enable. */
+ mask |= BIT(0);
+ }
+ rc = _bif_slave_masked_write(sdev, addr, 0xFF, mask);
+ if (rc) {
+ pr_err("BIF slave register masked write failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Set global auto task enable if task not in set 0. */
+ if (task / SLAVE_CTRL_TASKS_PER_SET != 0) {
+ addr = SLAVE_CTRL_FUNC_TASK_AUTO_TRIGGER_ADDR(
+ sdev->slave_ctrl_function->slave_ctrl_pointer, 0);
+ rc = _bif_slave_masked_write(sdev, addr, 0xFF, BIT(0));
+ if (rc) {
+ pr_err("BIF slave register masked write failed, rc=%d\n",
+ rc);
+ return rc;
+ }
+ }
+
+ return rc;
+}
+
+static int _bif_disable_auto_task(struct bif_slave_dev *sdev, unsigned int task)
+{
+ int rc;
+ u16 addr;
+ u8 mask;
+
+ rc = _bif_check_task(sdev, task);
+ if (rc) {
+ pr_err("Invalid slave or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Disable the auto task within the slave */
+ mask = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+ addr = SLAVE_CTRL_FUNC_TASK_AUTO_TRIGGER_ADDR(
+ sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ rc = _bif_slave_masked_write(sdev, addr, 0x00, mask);
+ if (rc) {
+ pr_err("BIF slave register masked write failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ return rc;
+}
+
/* Takes a mutex if this consumer is not an exclusive bus user. */
static void bif_ctrl_lock(struct bif_ctrl *ctrl)
{
@@ -608,22 +735,11 @@
static int bif_check_task(struct bif_slave *slave, unsigned int task)
{
if (IS_ERR_OR_NULL(slave)) {
- pr_err("Invalid slave handle.\n");
- return -EINVAL;
- } else if (!slave->sdev->bdev) {
- pr_err("BIF controller has been removed.\n");
- return -ENXIO;
- } else if (!slave->sdev->slave_ctrl_function
- || slave->sdev->slave_ctrl_function->task_count == 0) {
- pr_err("BIF slave does not support slave control.\n");
- return -ENODEV;
- } else if (task >= slave->sdev->slave_ctrl_function->task_count) {
- pr_err("Requested task: %u greater than max: %u for this slave\n",
- task, slave->sdev->slave_ctrl_function->task_count);
+ pr_err("Invalid slave pointer=%ld\n", PTR_ERR(slave));
return -EINVAL;
}
- return 0;
+ return _bif_check_task(slave->sdev, task);
}
/**
@@ -827,6 +943,61 @@
EXPORT_SYMBOL(bif_trigger_task);
/**
+ * bif_enable_auto_task() - enable task auto triggering for the specified task
+ * @slave: BIF slave handle
+ * @task: BIF task inside of the slave to configure for automatic
+ * triggering. This corresponds to the slave control channel
+ * specified for a given BIF function inside of the slave.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_enable_auto_task(struct bif_slave *slave, unsigned int task)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid slave pointer=%ld\n", PTR_ERR(slave));
+ return -EINVAL;
+ }
+
+ bif_slave_ctrl_lock(slave);
+ rc = _bif_enable_auto_task(slave->sdev, task);
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_enable_auto_task);
+
+/**
+ * bif_disable_auto_task() - disable task auto triggering for the specified task
+ * @slave: BIF slave handle
+ * @task: BIF task inside of the slave to stop automatic triggering on.
+ * This corresponds to the slave control channel specified for a
+ * given BIF function inside of the slave.
+ *
+ * This function should be called after bif_enable_auto_task() in a paired
+ * fashion.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_disable_auto_task(struct bif_slave *slave, unsigned int task)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid slave pointer=%ld\n", PTR_ERR(slave));
+ return -EINVAL;
+ }
+
+ bif_slave_ctrl_lock(slave);
+ rc = _bif_disable_auto_task(slave->sdev, task);
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_disable_auto_task);
+
+/**
* bif_task_is_busy() - checks the state of a BIF slave task
* @slave: BIF slave handle
* @task: BIF task inside of the slave to trigger. This corresponds to
@@ -838,28 +1009,14 @@
int bif_task_is_busy(struct bif_slave *slave, unsigned int task)
{
int rc;
- u16 addr;
- u8 reg;
- rc = bif_check_task(slave, task);
- if (rc) {
- pr_err("Invalid slave or task, rc=%d\n", rc);
- return rc;
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid slave pointer=%ld\n", PTR_ERR(slave));
+ return -EINVAL;
}
bif_slave_ctrl_lock(slave);
-
- /* Check the task busy state. */
- addr = SLAVE_CTRL_FUNC_TASK_BUSY_ADDR(
- slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
- rc = _bif_slave_read(slave->sdev, addr, ®, 1);
- if (rc) {
- pr_err("BIF slave register read failed, rc=%d\n", rc);
- goto done;
- }
-
- rc = (reg & BIT(task % SLAVE_CTRL_TASKS_PER_SET)) ? 1 : 0;
-done:
+ rc = _bif_task_is_busy(slave->sdev, task);
bif_slave_ctrl_unlock(slave);
return rc;
diff --git a/include/linux/bif/consumer.h b/include/linux/bif/consumer.h
index 4bfad62..8af7c93 100644
--- a/include/linux/bif/consumer.h
+++ b/include/linux/bif/consumer.h
@@ -472,6 +472,8 @@
struct notifier_block *nb);
int bif_trigger_task(struct bif_slave *slave, unsigned int task);
+int bif_enable_auto_task(struct bif_slave *slave, unsigned int task);
+int bif_disable_auto_task(struct bif_slave *slave, unsigned int task);
int bif_task_is_busy(struct bif_slave *slave, unsigned int task);
int bif_ctrl_count(void);
@@ -534,6 +536,12 @@
static inline int bif_trigger_task(struct bif_slave *slave, unsigned int task)
{ return -EPERM; }
+static inline int bif_enable_auto_task(struct bif_slave *slave,
+ unsigned int task)
+{ return -EPERM; }
+static inline int bif_disable_auto_task(struct bif_slave *slave,
+ unsigned int task)
+{ return -EPERM; }
static inline int bif_task_is_busy(struct bif_slave *slave, unsigned int task)
{ return -EPERM; }