On 10:00-20240729, Markus Schneider-Pargmann wrote: > Add support for Partial-IO poweroff. In Partial-IO pins of a few modules > can generate system wakeups while DDR memory is not powered resulting in > a fresh boot of the system. The modules that can be wakeup sources are > defined by the devicetree. > > Only wakeup sources that are actually enabled by the user will be > considered as a an active wakeup source. If none of the wakeup sources > are enabled the system will do a normal poweroff. If at least one wakeup > source is enabled it will instead send a TI_SCI_MSG_PREPARE_SLEEP > message from the sys_off handler. Sending this message will result in an > immediate shutdown of the system. No execution is expected after this > point. The code will enter an infinite loop. > > The wakeup source device nodes are gathered during probe. But they are > only resolved to the actual devices in the sys_off handler, if they > exist. If they do not exist, they are ignored. > > A short documentation about Partial-IO can be found in section 6.2.4.5 > of the TRM at > https://www.ti.com/lit/pdf/spruiv7 > > Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> > --- > drivers/firmware/ti_sci.c | 160 +++++++++++++++++++++++++++++++++----- > drivers/firmware/ti_sci.h | 34 ++++++++ > 2 files changed, 175 insertions(+), 19 deletions(-) > > diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c > index 160968301b1f..ba2e56da0215 100644 > --- a/drivers/firmware/ti_sci.c > +++ b/drivers/firmware/ti_sci.c > @@ -99,6 +99,9 @@ struct ti_sci_desc { > * @node: list head > * @host_id: Host ID > * @users: Number of users of this instance > + * @nr_wakeup_sources: Number of device nodes in wakeup_source_nodes > + * @wakeup_source_nodes: Array of all device_nodes listed as wakeup sources in > + * the devicetree > */ > struct ti_sci_info { > struct device *dev; > @@ -116,6 +119,9 @@ struct ti_sci_info { > u8 host_id; > /* protected by ti_sci_list_mutex */ > int users; > + > + int nr_wakeup_sources; > + struct device_node **wakeup_source_nodes; > }; > > #define cl_to_ti_sci_info(c) container_of(c, struct ti_sci_info, cl) > @@ -392,10 +398,13 @@ static void ti_sci_put_one_xfer(struct ti_sci_xfers_info *minfo, > static inline int ti_sci_do_xfer(struct ti_sci_info *info, > struct ti_sci_xfer *xfer) > { > + struct ti_sci_msg_hdr *hdr = (struct ti_sci_msg_hdr *)xfer->tx_message.buf; > int ret; > int timeout; > struct device *dev = info->dev; > bool done_state = true; > + bool response_expected = !!(hdr->flags & (TI_SCI_FLAG_REQ_ACK_ON_PROCESSED | > + TI_SCI_FLAG_REQ_ACK_ON_RECEIVED)); I think a separate patch to introduce a no_response expected patch would make sense on which we build tisci_sys_off_handler in the next patch? > > ret = mbox_send_message(info->chan_tx, &xfer->tx_message); > if (ret < 0) > @@ -403,25 +412,27 @@ static inline int ti_sci_do_xfer(struct ti_sci_info *info, > > ret = 0; > > - if (system_state <= SYSTEM_RUNNING) { > - /* And we wait for the response. */ > - timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms); > - if (!wait_for_completion_timeout(&xfer->done, timeout)) > - ret = -ETIMEDOUT; > - } else { > - /* > - * If we are !running, we cannot use wait_for_completion_timeout > - * during noirq phase, so we must manually poll the completion. > - */ > - ret = read_poll_timeout_atomic(try_wait_for_completion, done_state, > - done_state, 1, > - info->desc->max_rx_timeout_ms * 1000, > - false, &xfer->done); > - } > + if (response_expected) { How about a goto? if (!response_expected) goto no_response; > + if (system_state <= SYSTEM_RUNNING) { > + /* And we wait for the response. */ > + timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms); > + if (!wait_for_completion_timeout(&xfer->done, timeout)) > + ret = -ETIMEDOUT; > + } else { > + /* > + * If we are !running, we cannot use wait_for_completion_timeout > + * during noirq phase, so we must manually poll the completion. > + */ > + ret = read_poll_timeout_atomic(try_wait_for_completion, done_state, > + done_state, 1, > + info->desc->max_rx_timeout_ms * 1000, > + false, &xfer->done); > + } > > - if (ret == -ETIMEDOUT) > - dev_err(dev, "Mbox timedout in resp(caller: %pS)\n", > - (void *)_RET_IP_); > + if (ret == -ETIMEDOUT) > + dev_err(dev, "Mbox timedout in resp(caller: %pS)\n", > + (void *)_RET_IP_); > + } > no_response: > /* > * NOTE: we might prefer not to need the mailbox ticker to manage the > @@ -3262,6 +3273,82 @@ static int tisci_reboot_handler(struct sys_off_data *data) > return NOTIFY_BAD; > } > [...] > +static int tisci_sys_off_handler(struct sys_off_data *data) > +{ > + struct ti_sci_info *info = data->cb_data; > + int i; > + int ret; > + bool enter_partial_io = false; > + > + for (i = 0; i != info->nr_wakeup_sources; ++i) { > + struct platform_device *pdev = > + of_find_device_by_node(info->wakeup_source_nodes[i]); > + > + if (!pdev) > + continue; > + > + if (device_may_wakeup(&pdev->dev)) { > + dev_dbg(info->dev, "%pOFp identified as wakeup source\n", > + info->wakeup_source_nodes[i]); > + enter_partial_io = true; > + } > + } > + > + if (!enter_partial_io) > + return NOTIFY_DONE; > + > + ret = tisci_enter_partial_io(info); > + > + if (ret) { > + dev_err(info->dev, > + "Failed to enter Partial-IO %pe, trying to do an emergency restart\n", > + ERR_PTR(ret)); > + emergency_restart(); > + } > + > + while (1); Why not fall through OR go through emergency_restart (since there is no fall through for shutdown path) if it acks, but actually fails to enter LPM state after a dt described or a default timeout period? > + > + return NOTIFY_DONE; > +} > + > /* Description for K2G */ > static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = { > .default_host_id = 2, > @@ -3398,6 +3485,35 @@ static int ti_sci_probe(struct platform_device *pdev) > goto out; > } > > + if (of_property_read_bool(dev->of_node, "ti,partial-io-wakeup-sources")) { You should probably check on TISCI_MSG_QUERY_FW_CAPS[1] if Partial IO on low power mode is supported as well? if there is a mismatch, report so? > + info->nr_wakeup_sources = > + of_count_phandle_with_args(dev->of_node, > + "ti,partial-io-wakeup-sources", > + NULL); > + info->wakeup_source_nodes = > + devm_kzalloc(dev, sizeof(*info->wakeup_source_nodes), > + GFP_KERNEL); > + > + for (i = 0; i != info->nr_wakeup_sources; ++i) { > + struct device_node *devnode = > + of_parse_phandle(dev->of_node, > + "ti,partial-io-wakeup-sources", > + i); > + info->wakeup_source_nodes[i] = devnode; Curious: Don't we need to maintain reference counting for the devnode if CONFIG_OF_DYNAMIC? [...] [1] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/general/core.html#tisci-msg-query-fw-caps -- Regards, Nishanth Menon Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D
