Messages in this thread | | | Date | Thu, 3 Aug 2023 11:00:11 -0500 | Subject | Re: [PATCH V6 4/4] firmware: ti_sci: Introduce system suspend resume support | From | Andrew Davis <> |
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On 8/3/23 10:55 AM, Dhruva Gole wrote: > On Aug 03, 2023 at 10:26:32 -0500, Andrew Davis wrote: >> On 8/3/23 1:42 AM, Dhruva Gole wrote: >>> Introduce system suspend resume calls that will allow the ti_sci >>> driver to support deep sleep low power mode when the user space issues a >>> suspend to mem. >>> >>> Also, write a ti_sci_prepare_system_suspend call to be used in the driver >>> suspend handler to allow the system to identify the low power mode being >>> entered and if necessary, send TISCI_MSG_PREPARE_SLEEP with information >>> about the mode is being entered and the address for allocated memory for >>> storing the context during Deep Sleep. >>> >>> We're using "pm_suspend_target_state" to map the kernel's target suspend >>> state to SysFW low power mode. Make sure this is available only when >>> CONFIG_SUSPEND is enabled. >>> >>> Co-developed-by: Dave Gerlach <d-gerlach@ti.com> >>> Signed-off-by: Dave Gerlach <d-gerlach@ti.com> >>> Signed-off-by: Vibhore Vardhan <vibhore@ti.com> >>> Signed-off-by: Georgi Vlaev <g-vlaev@ti.com> >>> Signed-off-by: Dhruva Gole <d-gole@ti.com> >>> --- >>> drivers/firmware/ti_sci.c | 63 +++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 63 insertions(+) >>> > [..snip..] >>> +static int ti_sci_suspend(struct device *dev) >>> +{ >>> + struct ti_sci_info *info = dev_get_drvdata(dev); >>> + int ret; >>> + >>> + ret = ti_sci_cmd_set_io_isolation(&info->handle, TISCI_MSG_VALUE_IO_ENABLE); >> >> After this the will the IOs be in isolation? Or does the firmware wait >> until power down begins later? > > From what I understand, > IOs will be in isolation immediately >
That is what I understand too, so then any device that may need to do some external communication for its suspend will not function, this must be the last driver _suspend() the system calls, how do you enforce that?
Andrew
>> >> Andrew >> >>> + if (ret) >>> + return ret; >>> + dev_dbg(dev, "%s: set I/O isolation: %d\n", __func__, ret); >>> + >>> + ret = ti_sci_prepare_system_suspend(info); >>> + if (ret) >>> + return ret; >>> + >>> + return 0; >>> +} >>> + >>> +static int ti_sci_resume(struct device *dev) >>> +{ >>> + struct ti_sci_info *info = dev_get_drvdata(dev); >>> + int ret; >>> + >>> + ret = ti_sci_cmd_set_io_isolation(&info->handle, TISCI_MSG_VALUE_IO_DISABLE); >>> + if (ret) >>> + return ret; >>> + dev_dbg(dev, "%s: disable I/O isolation: %d\n", __func__, ret); >>> + >>> + return 0; >>> +} >>> + >>> +static DEFINE_SIMPLE_DEV_PM_OPS(ti_sci_pm_ops, ti_sci_suspend, ti_sci_resume); >>> + >>> static int ti_sci_init_suspend(struct platform_device *pdev, >>> struct ti_sci_info *info) >>> { >>> @@ -3759,6 +3821,7 @@ static struct platform_driver ti_sci_driver = { >>> .driver = { >>> .name = "ti-sci", >>> .of_match_table = of_match_ptr(ti_sci_of_match), >>> + .pm = &ti_sci_pm_ops, >>> }, >>> }; >>> module_platform_driver(ti_sci_driver); >
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