Thanks for the review comments
On 07/10/17 09:06, Jonathan Neuschäfer wrote:
Hi, some trivial comments below.
On Fri, Oct 06, 2017 at 05:51:33PM +0200, srinivas.kandagatla@xxxxxxxxxx wrote:
From: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
Per slimbus specification, a reconfiguration sequence known as
'clock pause' needs to be broadcast over the bus while entering low-
power mode. Clock-pause is initiated by the controller driver.
To exit clock-pause, controller typically wakes up the framer device.
Since wakeup precedure is controller-specific, framework calls it via
controller's function pointer to invoke it.
Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
[...]
@@ -429,6 +444,14 @@ void slim_return_tx(struct slim_controller *ctrl, int err)
cur.cb(cur.ctx, err);
up(&ctrl->tx_sem);
+ if (!cur.clk_pause && (!cur.need_tid || err)) {
+ /**
This isn't really a kerneldoc comment.
Will fix all such instances in next version.
+ * remove runtime-pm vote if this was TX only, or
+ * if there was error during this transaction
+ */
+ pm_runtime_mark_last_busy(ctrl->dev.parent);
+ pm_runtime_put_autosuspend(ctrl->dev.parent);
+ }
}
EXPORT_SYMBOL_GPL(slim_return_tx);
[...]
+/**
+ * slim_ctrl_clk_pause: Called by slimbus controller to enter/exit 'clock pause'
+ * Slimbus specification needs this sequence to turn-off clocks for the bus.
+ * The sequence involves sending 3 broadcast messages (reconfiguration
+ * sequence) to inform all devices on the bus.
+ * To exit clock-pause, controller typically wakes up active framer device.
+ * @ctrl: controller requesting bus to be paused or woken up
+ * @wakeup: Wakeup this controller from clock pause.
+ * @restart: Restart time value per spec used for clock pause. This value
+ * isn't used when controller is to be woken up.
+ * This API executes clock pause reconfiguration sequence if wakeup is false.
+ * If wakeup is true, controller's wakeup is called.
+ * For entering clock-pause, -EBUSY is returned if a message txn in pending.
+ */
+int slim_ctrl_clk_pause(struct slim_controller *ctrl, bool wakeup, u8 restart)
+{
+ int i, ret = 0;
+ unsigned long flags;
+ struct slim_sched *sched = &ctrl->sched;
+ struct slim_val_inf msg = {0, 0, NULL, NULL, NULL, NULL};
+
+ DEFINE_SLIM_BCAST_TXN(txn, SLIM_MSG_MC_BEGIN_RECONFIGURATION,
+ 3, SLIM_LA_MANAGER, &msg);
+
+ if (wakeup == false && restart > SLIM_CLK_UNSPECIFIED)
+ return -EINVAL;
+
+ mutex_lock(&sched->m_reconf);
+ if (wakeup) {
+ if (sched->clk_state == SLIM_CLK_ACTIVE) {
+ mutex_unlock(&sched->m_reconf);
+ return 0;
+ }
+
+ /**
ditto
+ * Fine-tune calculation based on clock gear,
+ * message-bandwidth after bandwidth management
+ */
+ ret = wait_for_completion_timeout(&sched->pause_comp,
+ msecs_to_jiffies(100));
+ if (!ret) {
+ mutex_unlock(&sched->m_reconf);
+ pr_err("Previous clock pause did not finish");
+ return -ETIMEDOUT;
+ }
+ ret = 0;
+
+ /**
ditto
+ * Slimbus framework will call controller wakeup
+ * Controller should make sure that it sets active framer
+ * out of clock pause
+ */
+ if (sched->clk_state == SLIM_CLK_PAUSED && ctrl->wakeup)
+ ret = ctrl->wakeup(ctrl);
+ if (!ret)
+ sched->clk_state = SLIM_CLK_ACTIVE;
+ mutex_unlock(&sched->m_reconf);
+
+ return ret;
+ }
[...]
Thanks,
Jonathan Neuschäfer
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