| Message ID | 20240523080225.1288617-3-msp@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | firmware: ti_sci: Partial-IO support | expand |
On 10:02-20240523, 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. Would have helped to provide link to relevant documentation here. > > Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com> > --- > drivers/firmware/ti_sci.c | 135 +++++++++++++++++++++++++++++++++++++- > drivers/firmware/ti_sci.h | 31 +++++++++ > 2 files changed, 165 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c > index 160968301b1f..04730c4df2de 100644 > --- a/drivers/firmware/ti_sci.c > +++ b/drivers/firmware/ti_sci.c > @@ -116,6 +116,9 @@ 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; Documentation please. > }; > > #define cl_to_ti_sci_info(c) container_of(c, struct ti_sci_info, cl) > @@ -380,6 +383,28 @@ static void ti_sci_put_one_xfer(struct ti_sci_xfers_info *minfo, > up(&minfo->sem_xfer_count); > } > > +/** > + * ti_sci_do_send() - Do one send, do not expect a response is ti_sci_send_no_response() a better name? I have a basic question about an API at kernel level that does'nt return back.. but I will ask in the context of tisci_enter_partial_io below. > + * @info: Pointer to SCI entity information > + * @xfer: Transfer to initiate > + * > + * Return: If send error, return corresponding error, else > + * if all goes well, return 0. > + */ > +static inline int ti_sci_do_send(struct ti_sci_info *info, > + struct ti_sci_xfer *xfer) > +{ > + int ret; should'nt we make sure TI_SCI_FLAG_REQ_ACK_ON_PROCESSED is not set? > + > + ret = mbox_send_message(info->chan_tx, &xfer->tx_message); > + if (ret < 0) > + return ret; > + > + mbox_client_txdone(info->chan_tx, ret); > + > + return 0; > +} > + I am not sure I like two functions sending mbox_send_message. what do you think of the following? Use xfer-> hdr.flags and check against TI_SCI_FLAG_REQ_ACK_ON_PROCESSED itself to decide if ti_sci_do_xfer should expect a response or not? > /** > * ti_sci_do_xfer() - Do one transfer > * @info: Pointer to SCI entity information > @@ -3262,6 +3287,79 @@ static int tisci_reboot_handler(struct sys_off_data *data) > return NOTIFY_BAD; > } > > +/* Does not return if successful */ It wasn't clear from the commit message the strategy used. You are triggering system off path here - do we loose the contents of DDR in this flow? The power state needs to clearly described and the rationale of using a variant of "off" path documented as well. Looking further in to the code, I see we are unconditionally registering the sys_off_handler based on ti,partial-io-wakeup-sources property being present - how do we differentiate between actual PMIC power off desire of user Vs just a few IO down power state for the user. > +static int tisci_enter_partial_io(struct ti_sci_info *info) > +{ > + struct ti_sci_msg_req_prepare_sleep *req; > + struct ti_sci_xfer *xfer; > + struct device *dev = info->dev; > + int ret = 0; > + > + xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_PREPARE_SLEEP, > + TI_SCI_FLAG_REQ_GENERIC_NORESPONSE, > + sizeof(*req), sizeof(struct ti_sci_msg_hdr)); > + if (IS_ERR(xfer)) { > + ret = PTR_ERR(xfer); > + dev_err(dev, "Message alloc failed(%d)\n", ret); > + return ret; > + } > + > + req = (struct ti_sci_msg_req_prepare_sleep *)xfer->xfer_buf; > + req->mode = TISCI_MSG_VALUE_SLEEP_MODE_PARTIAL_IO; > + req->ctx_lo = 0; > + req->ctx_hi = 0; > + req->debug_flags = 0; > + > + ret = ti_sci_do_send(info, xfer); > + if (ret) { > + dev_err(dev, "Mbox send fail %d\n", ret); > + goto fail; > + } > + > +fail: > + ti_sci_put_one_xfer(&info->minfo, xfer); > + > + return ret; > +} > + > +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, halting system\n", > + ERR_PTR(ret)); Is there no other diagnostics we can provide here? > + > + /* Halt system/code execution */ > + while (1) > + ; Why halt (1) -> spinning CPU in a while loop is not a power save mode (at least idle?) :D Why not fall through and loose power state context and allow the PMIC or some other shutdown handler to attempt to power off? > + > + return NOTIFY_DONE; > +} > + > /* Description for K2G */ > static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = { > .default_host_id = 2, > @@ -3398,6 +3496,35 @@ static int ti_sci_probe(struct platform_device *pdev) > goto out; > } > > + if (of_property_read_bool(dev->of_node, "ti,partial-io-wakeup-sources")) { > + 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; > + } > + > + ret = devm_register_sys_off_handler(dev, > + SYS_OFF_MODE_POWER_OFF, > + SYS_OFF_PRIO_FIRMWARE, > + tisci_sys_off_handler, > + info); > + if (ret) { > + dev_err(dev, "Failed to register sys_off_handler %pe\n", > + ERR_PTR(ret)); > + goto out; > + } > + } > + > dev_info(dev, "ABI: %d.%d (firmware rev 0x%04x '%s')\n", > info->handle.version.abi_major, info->handle.version.abi_minor, > info->handle.version.firmware_revision, > @@ -3407,7 +3534,13 @@ static int ti_sci_probe(struct platform_device *pdev) > list_add_tail(&info->node, &ti_sci_list); > mutex_unlock(&ti_sci_list_mutex); > > - return of_platform_populate(dev->of_node, NULL, NULL, dev); > + ret = of_platform_populate(dev->of_node, NULL, NULL, dev); > + if (ret) { > + dev_err(dev, "platform_populate failed %pe\n", ERR_PTR(ret)); > + goto out; > + } > + return 0; Unrelated change - please separate into different patch. Sounds like a fix? > + > out: > if (!IS_ERR(info->chan_tx)) > mbox_free_channel(info->chan_tx); > diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h > index ef3a8214d002..6d8b12341f68 100644 > --- a/drivers/firmware/ti_sci.h > +++ b/drivers/firmware/ti_sci.h > @@ -35,6 +35,9 @@ > #define TI_SCI_MSG_QUERY_CLOCK_FREQ 0x010d > #define TI_SCI_MSG_GET_CLOCK_FREQ 0x010e > > +/* Low Power Mode Requests */ > +#define TI_SCI_MSG_PREPARE_SLEEP 0x0300 Looking at https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#device-configuration-and-control-apis Don't you need TISCI_MSG_SET_IO_ISOLATION support? Also, reading https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#tisci-msg-enter-sleep "This message is to be sent after TISCI_MSG_PREPARE_SLEEP and actually triggers entry into the specified low power mode." our call sequence seems to be just prepare_sleep and expect it to power off the SoC? does'nt the PMIC need to be powered off? > + > /* Resource Management Requests */ > #define TI_SCI_MSG_GET_RESOURCE_RANGE 0x1500 > > @@ -545,6 +548,34 @@ struct ti_sci_msg_resp_get_clock_freq { > u64 freq_hz; > } __packed; > > +#define TISCI_MSG_VALUE_SLEEP_MODE_DEEP_SLEEP 0x0 > +#define TISCI_MSG_VALUE_SLEEP_MODE_MCU_ONLY 0x1 > +#define TISCI_MSG_VALUE_SLEEP_MODE_STANDBY 0x2 > +#define TISCI_MSG_VALUE_SLEEP_MODE_PARTIAL_IO 0x3 Where are these values coming from? https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#tisci-msg-prepare-sleep Does not seem to have these? I think we are picking from: https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#supported-low-power-modes ? The documentation could use a little cleanup there :( > + > +/** > + * struct tisci_msg_prepare_sleep_req - Request for TISCI_MSG_PREPARE_SLEEP. s/tisci_msg_prepare_sleep_req/ti_sci_msg_req_prepare_sleep ? > + * > + * @hdr TISCI header to provide ACK/NAK flags to the host. > + * @mode Low power mode to enter. > + * @ctx_lo Low 32-bits of physical pointer to address to use for context save. > + * @ctx_hi High 32-bits of physical pointer to address to use for context save. > + * @debug_flags Flags that can be set to halt the sequence during suspend or > + * resume to allow JTAG connection and debug. There are no schemes to enable there? Are we going to manually modify the driver for every step of the debug? > + * > + * This message is used as the first step of entering a low power mode. It > + * allows configurable information, including which state to enter to be > + * easily shared from the application, as this is a non-secure message and > + * therefore can be sent by anyone. > + */ > +struct ti_sci_msg_req_prepare_sleep { > + struct ti_sci_msg_hdr hdr; > + u8 mode; > + u32 ctx_lo; > + u32 ctx_hi; > + u32 debug_flags; > +} __packed; Also are we supposed to use this header for other low power sequences? From the definitions of TISCI_MSG_VALUE_SLEEP_MODE_* it looks like there are additional usage? Just trying to understand if follow on patches will not have to refactor things here. > + > #define TI_SCI_IRQ_SECONDARY_HOST_INVALID 0xff > > /** > -- > 2.43.0 >
diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c index 160968301b1f..04730c4df2de 100644 --- a/drivers/firmware/ti_sci.c +++ b/drivers/firmware/ti_sci.c @@ -116,6 +116,9 @@ 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) @@ -380,6 +383,28 @@ static void ti_sci_put_one_xfer(struct ti_sci_xfers_info *minfo, up(&minfo->sem_xfer_count); } +/** + * ti_sci_do_send() - Do one send, do not expect a response + * @info: Pointer to SCI entity information + * @xfer: Transfer to initiate + * + * Return: If send error, return corresponding error, else + * if all goes well, return 0. + */ +static inline int ti_sci_do_send(struct ti_sci_info *info, + struct ti_sci_xfer *xfer) +{ + int ret; + + ret = mbox_send_message(info->chan_tx, &xfer->tx_message); + if (ret < 0) + return ret; + + mbox_client_txdone(info->chan_tx, ret); + + return 0; +} + /** * ti_sci_do_xfer() - Do one transfer * @info: Pointer to SCI entity information @@ -3262,6 +3287,79 @@ static int tisci_reboot_handler(struct sys_off_data *data) return NOTIFY_BAD; } +/* Does not return if successful */ +static int tisci_enter_partial_io(struct ti_sci_info *info) +{ + struct ti_sci_msg_req_prepare_sleep *req; + struct ti_sci_xfer *xfer; + struct device *dev = info->dev; + int ret = 0; + + xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_PREPARE_SLEEP, + TI_SCI_FLAG_REQ_GENERIC_NORESPONSE, + sizeof(*req), sizeof(struct ti_sci_msg_hdr)); + if (IS_ERR(xfer)) { + ret = PTR_ERR(xfer); + dev_err(dev, "Message alloc failed(%d)\n", ret); + return ret; + } + + req = (struct ti_sci_msg_req_prepare_sleep *)xfer->xfer_buf; + req->mode = TISCI_MSG_VALUE_SLEEP_MODE_PARTIAL_IO; + req->ctx_lo = 0; + req->ctx_hi = 0; + req->debug_flags = 0; + + ret = ti_sci_do_send(info, xfer); + if (ret) { + dev_err(dev, "Mbox send fail %d\n", ret); + goto fail; + } + +fail: + ti_sci_put_one_xfer(&info->minfo, xfer); + + return ret; +} + +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, halting system\n", + ERR_PTR(ret)); + + /* Halt system/code execution */ + while (1) + ; + + return NOTIFY_DONE; +} + /* Description for K2G */ static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = { .default_host_id = 2, @@ -3398,6 +3496,35 @@ static int ti_sci_probe(struct platform_device *pdev) goto out; } + if (of_property_read_bool(dev->of_node, "ti,partial-io-wakeup-sources")) { + 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; + } + + ret = devm_register_sys_off_handler(dev, + SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_FIRMWARE, + tisci_sys_off_handler, + info); + if (ret) { + dev_err(dev, "Failed to register sys_off_handler %pe\n", + ERR_PTR(ret)); + goto out; + } + } + dev_info(dev, "ABI: %d.%d (firmware rev 0x%04x '%s')\n", info->handle.version.abi_major, info->handle.version.abi_minor, info->handle.version.firmware_revision, @@ -3407,7 +3534,13 @@ static int ti_sci_probe(struct platform_device *pdev) list_add_tail(&info->node, &ti_sci_list); mutex_unlock(&ti_sci_list_mutex); - return of_platform_populate(dev->of_node, NULL, NULL, dev); + ret = of_platform_populate(dev->of_node, NULL, NULL, dev); + if (ret) { + dev_err(dev, "platform_populate failed %pe\n", ERR_PTR(ret)); + goto out; + } + return 0; + out: if (!IS_ERR(info->chan_tx)) mbox_free_channel(info->chan_tx); diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h index ef3a8214d002..6d8b12341f68 100644 --- a/drivers/firmware/ti_sci.h +++ b/drivers/firmware/ti_sci.h @@ -35,6 +35,9 @@ #define TI_SCI_MSG_QUERY_CLOCK_FREQ 0x010d #define TI_SCI_MSG_GET_CLOCK_FREQ 0x010e +/* Low Power Mode Requests */ +#define TI_SCI_MSG_PREPARE_SLEEP 0x0300 + /* Resource Management Requests */ #define TI_SCI_MSG_GET_RESOURCE_RANGE 0x1500 @@ -545,6 +548,34 @@ struct ti_sci_msg_resp_get_clock_freq { u64 freq_hz; } __packed; +#define TISCI_MSG_VALUE_SLEEP_MODE_DEEP_SLEEP 0x0 +#define TISCI_MSG_VALUE_SLEEP_MODE_MCU_ONLY 0x1 +#define TISCI_MSG_VALUE_SLEEP_MODE_STANDBY 0x2 +#define TISCI_MSG_VALUE_SLEEP_MODE_PARTIAL_IO 0x3 + +/** + * struct tisci_msg_prepare_sleep_req - Request for TISCI_MSG_PREPARE_SLEEP. + * + * @hdr TISCI header to provide ACK/NAK flags to the host. + * @mode Low power mode to enter. + * @ctx_lo Low 32-bits of physical pointer to address to use for context save. + * @ctx_hi High 32-bits of physical pointer to address to use for context save. + * @debug_flags Flags that can be set to halt the sequence during suspend or + * resume to allow JTAG connection and debug. + * + * This message is used as the first step of entering a low power mode. It + * allows configurable information, including which state to enter to be + * easily shared from the application, as this is a non-secure message and + * therefore can be sent by anyone. + */ +struct ti_sci_msg_req_prepare_sleep { + struct ti_sci_msg_hdr hdr; + u8 mode; + u32 ctx_lo; + u32 ctx_hi; + u32 debug_flags; +} __packed; + #define TI_SCI_IRQ_SECONDARY_HOST_INVALID 0xff /**
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. Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com> --- drivers/firmware/ti_sci.c | 135 +++++++++++++++++++++++++++++++++++++- drivers/firmware/ti_sci.h | 31 +++++++++ 2 files changed, 165 insertions(+), 1 deletion(-)