On 22/02/2022 19:15, Pierre-Louis Bossart wrote:
On 2/21/22 04:41, Srinivas Kandagatla wrote:
Add support to runtime PM using SoundWire clock stop on supported instances
and bus reset on instances that require full reset.
This commit message and code are a bit confusing, e.g. you have a
boolean state
ctrl->clk_stop_bus_reset = true;
Does this mean bus reset on exiting clock stop? or just that clock stop
is not supported and bus reset is required with complete re-enumeration.
WSA instances of SoundWire controllers do not support clk stop and a
reset of ip is required with complete re-enumeration when a clock is cut
off during suspend.
It would be good to try and explain using SoundWire 1.x terminology what
actions are taken on resume.
There are two cases here.
1> Controller Instance support ClockStop Mode0, we mostly use the
generic core to do that except in resume path we make sure that we start
the clock.
2> Controller Instances which that do not support ClockStop, we do soft
reset of controller along with hard resetting slaves.
@@ -1267,6 +1305,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
ctrl->bus.ops = &qcom_swrm_ops;
ctrl->bus.port_ops = &qcom_swrm_port_ops;
ctrl->bus.compute_params = &qcom_swrm_compute_params;
+ ctrl->bus.clk_stop_timeout = 300;
ret = qcom_swrm_get_port_config(ctrl);
if (ret)
@@ -1319,6 +1358,21 @@ static int qcom_swrm_probe(struct platform_device *pdev)
(ctrl->version >> 24) & 0xff, (ctrl->version >> 16) & 0xff,
ctrl->version & 0xffff);
+ pm_runtime_set_autosuspend_delay(dev, 3000);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ /* Clk stop is not supported on WSA Soundwire masters */
+ if (ctrl->version <= 0x01030000) {
+ ctrl->clk_stop_bus_reset = true;
+ } else {
+ ctrl->reg_read(ctrl, SWRM_COMP_MASTER_ID, &val);
+ if (val == MASTER_ID_WSA)
+ ctrl->clk_stop_bus_reset = true;
+ }
I think this means clock_stop_not_supported?
Yes It makes more sense to reword this to clock_stop_not_supported.
+static int swrm_runtime_resume(struct device *dev)
+{
+ struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);
+ int ret;
+
+ clk_prepare_enable(ctrl->hclk);
+
+ if (ctrl->clk_stop_bus_reset) {
+ reinit_completion(&ctrl->enumeration);
+ ctrl->reg_write(ctrl, SWRM_COMP_SW_RESET, 0x01);
+ qcom_swrm_get_device_status(ctrl);
don't you need some sort of delay before checking the controller and
device status? The bus reset sequence takes 4096 bits, that's a non-zero
time.
This is soft reset not full Bus Reset as WSA slaves have hard reset pins
that will be toggled as part of suspend-resume.
+ sdw_handle_slave_status(&ctrl->bus, ctrl->status);
+ qcom_swrm_init(ctrl);
+ wait_for_completion_timeout(&ctrl->enumeration,
+ msecs_to_jiffies(TIMEOUT_MS));
+ } else {
+ ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL, SWRM_MCP_BUS_CLK_START);
+ ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR,
+ SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET);
+
+ ctrl->intr_mask |= SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET;
+ ctrl->reg_write(ctrl, SWRM_INTERRUPT_MASK_ADDR, ctrl->intr_mask);
+ ctrl->reg_write(ctrl, SWRM_INTERRUPT_CPU_EN, ctrl->intr_mask);
+
+ usleep_range(100, 105);
+ }
+
+ if (!swrm_wait_for_frame_gen_enabled(ctrl))
+ dev_err(ctrl->dev, "link failed to connect\n");
+
+ usleep_range(300, 305);
+ ret = sdw_bus_exit_clk_stop(&ctrl->bus);
+ if (ret < 0)
+ dev_err(ctrl->dev, "bus failed to exit clock stop %d\n", ret);
+
+ return 0;
+}
+
+static int __maybe_unused swrm_runtime_suspend(struct device *dev)
+{
+ struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);
+ int ret;
+
+ if (!ctrl->clk_stop_bus_reset) {
+ /* Mask bus clash interrupt */
+ ctrl->intr_mask &= ~SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET;
+ ctrl->reg_write(ctrl, SWRM_INTERRUPT_MASK_ADDR, ctrl->intr_mask);
+ ctrl->reg_write(ctrl, SWRM_INTERRUPT_CPU_EN, ctrl->intr_mask);
+ }
+ /* Prepare slaves for clock stop */
+ ret = sdw_bus_prep_clk_stop(&ctrl->bus);
+ if (ret < 0) {
if a device has lost sync and reports -ENODATA, you want still want to
go ahead and not prevent the suspend operation from happening.
okay.
--srini
+ dev_err(dev, "prepare clock stop failed %d", ret);
+ return ret;
+ }
+
+ ret = sdw_bus_clk_stop(&ctrl->bus);
+ if (ret < 0 && ret != -ENODATA) {
+ dev_err(dev, "bus clock stop failed %d", ret);
+ return ret;
+ }
+
+ clk_disable_unprepare(ctrl->hclk);
+
+ usleep_range(300, 305);
+
+ return 0;
+}
+
+static const struct dev_pm_ops swrm_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(swrm_runtime_suspend, swrm_runtime_resume, NULL)
+};
+
static const struct of_device_id qcom_swrm_of_match[] = {
{ .compatible = "qcom,soundwire-v1.3.0", .data = &swrm_v1_3_data },
{ .compatible = "qcom,soundwire-v1.5.1", .data = &swrm_v1_5_data },
@@ -1359,6 +1506,7 @@ static struct platform_driver qcom_swrm_driver = {
.driver = {
.name = "qcom-soundwire",
.of_match_table = qcom_swrm_of_match,
+ .pm = &swrm_dev_pm_ops,
}
};
module_platform_driver(qcom_swrm_driver);
