// SPDX-License-Identifier: GPL-2.0 /* * Xilinx Inter Processor Interrupt(IPI) Mailbox Driver * * Copyright (C) 2018 Xilinx, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* IPI agent ID any */ #define IPI_ID_ANY 0xFFUL /* indicate if ZynqMP IPI mailbox driver uses SMC calls or HVC calls */ #define USE_SMC 0 #define USE_HVC 1 /* Default IPI SMC function IDs */ #define SMC_IPI_MAILBOX_OPEN 0x82001000U #define SMC_IPI_MAILBOX_RELEASE 0x82001001U #define SMC_IPI_MAILBOX_STATUS_ENQUIRY 0x82001002U #define SMC_IPI_MAILBOX_NOTIFY 0x82001003U #define SMC_IPI_MAILBOX_ACK 0x82001004U #define SMC_IPI_MAILBOX_ENABLE_IRQ 0x82001005U #define SMC_IPI_MAILBOX_DISABLE_IRQ 0x82001006U /* IPI SMC Macros */ #define IPI_SMC_ENQUIRY_DIRQ_MASK 0x00000001UL /* Flag to indicate if * notification interrupt * to be disabled. */ #define IPI_SMC_ACK_EIRQ_MASK 0x00000001UL /* Flag to indicate if * notification interrupt * to be enabled. */ /* IPI mailbox status */ #define IPI_MB_STATUS_IDLE 0 #define IPI_MB_STATUS_SEND_PENDING 1 #define IPI_MB_STATUS_RECV_PENDING 2 #define IPI_MB_CHNL_TX 0 /* IPI mailbox TX channel */ #define IPI_MB_CHNL_RX 1 /* IPI mailbox RX channel */ /** * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel * @is_opened: indicate if the IPI channel is opened * @req_buf: local to remote request buffer start address * @resp_buf: local to remote response buffer start address * @req_buf_size: request buffer size * @resp_buf_size: response buffer size * @rx_buf: receive buffer to pass received message to client * @chan_type: channel type */ struct zynqmp_ipi_mchan { int is_opened; void __iomem *req_buf; void __iomem *resp_buf; void *rx_buf; size_t req_buf_size; size_t resp_buf_size; unsigned int chan_type; }; /** * struct zynqmp_ipi_mbox - Description of a ZynqMP IPI mailbox * platform data. * @pdata: pointer to the IPI private data * @dev: device pointer corresponding to the Xilinx ZynqMP * IPI mailbox * @remote_id: remote IPI agent ID * @mbox: mailbox Controller * @mchans: array for channels, tx channel and rx channel. * @irq: IPI agent interrupt ID */ struct zynqmp_ipi_mbox { struct zynqmp_ipi_pdata *pdata; struct device dev; u32 remote_id; struct mbox_controller mbox; struct zynqmp_ipi_mchan mchans[2]; }; /** * struct zynqmp_ipi_pdata - Description of z ZynqMP IPI agent platform data. * * @dev: device pointer corresponding to the Xilinx ZynqMP * IPI agent * @irq: IPI agent interrupt ID * @method: IPI SMC or HVC is going to be used * @local_id: local IPI agent ID * @num_mboxes: number of mailboxes of this IPI agent * @ipi_mboxes: IPI mailboxes of this IPI agent */ struct zynqmp_ipi_pdata { struct device *dev; int irq; unsigned int method; u32 local_id; int num_mboxes; struct zynqmp_ipi_mbox *ipi_mboxes; }; static struct device_driver zynqmp_ipi_mbox_driver = { .owner = THIS_MODULE, .name = "zynqmp-ipi-mbox", }; static void zynqmp_ipi_fw_call(struct zynqmp_ipi_mbox *ipi_mbox, unsigned long a0, unsigned long a3, struct arm_smccc_res *res) { struct zynqmp_ipi_pdata *pdata = ipi_mbox->pdata; unsigned long a1, a2; a1 = pdata->local_id; a2 = ipi_mbox->remote_id; if (pdata->method == USE_SMC) arm_smccc_smc(a0, a1, a2, a3, 0, 0, 0, 0, res); else arm_smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, res); } /** * zynqmp_ipi_interrupt - Interrupt handler for IPI notification * * @irq: Interrupt number * @data: ZynqMP IPI mailbox platform data. * * Return: -EINVAL if there is no instance * IRQ_NONE if the interrupt is not ours. * IRQ_HANDLED if the rx interrupt was successfully handled. */ static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data) { struct zynqmp_ipi_pdata *pdata = data; struct mbox_chan *chan; struct zynqmp_ipi_mbox *ipi_mbox; struct zynqmp_ipi_mchan *mchan; struct zynqmp_ipi_message *msg; u64 arg0, arg3; struct arm_smccc_res res; int ret, i; (void)irq; arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY; arg3 = IPI_SMC_ENQUIRY_DIRQ_MASK; for (i = 0; i < pdata->num_mboxes; i++) { ipi_mbox = &pdata->ipi_mboxes[i]; mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX]; chan = &ipi_mbox->mbox.chans[IPI_MB_CHNL_RX]; zynqmp_ipi_fw_call(ipi_mbox, arg0, arg3, &res); ret = (int)(res.a0 & 0xFFFFFFFF); if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) { if (mchan->is_opened) { msg = mchan->rx_buf; msg->len = mchan->req_buf_size; memcpy_fromio(msg->data, mchan->req_buf, msg->len); mbox_chan_received_data(chan, (void *)msg); return IRQ_HANDLED; } } } return IRQ_NONE; } /** * zynqmp_ipi_peek_data - Peek to see if there are any rx messages. * * @chan: Channel Pointer * * Return: 'true' if there is pending rx data, 'false' if there is none. */ static bool zynqmp_ipi_peek_data(struct mbox_chan *chan) { struct device *dev = chan->mbox->dev; struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev); struct zynqmp_ipi_mchan *mchan = chan->con_priv; int ret; u64 arg0; struct arm_smccc_res res; if (WARN_ON(!ipi_mbox)) { dev_err(dev, "no platform drv data??\n"); return false; } arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); ret = (int)(res.a0 & 0xFFFFFFFF); if (mchan->chan_type == IPI_MB_CHNL_TX) { /* TX channel, check if the message has been acked * by the remote, if yes, response is available. */ if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING) return false; else return true; } else if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) { /* RX channel, check if there is message arrived. */ return true; } return false; } /** * zynqmp_ipi_last_tx_done - See if the last tx message is sent * * @chan: Channel pointer * * Return: 'true' is no pending tx data, 'false' if there are any. */ static bool zynqmp_ipi_last_tx_done(struct mbox_chan *chan) { struct device *dev = chan->mbox->dev; struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev); struct zynqmp_ipi_mchan *mchan = chan->con_priv; int ret; u64 arg0; struct arm_smccc_res res; if (WARN_ON(!ipi_mbox)) { dev_err(dev, "no platform drv data??\n"); return false; } if (mchan->chan_type == IPI_MB_CHNL_TX) { /* We only need to check if the message been taken * by the remote in the TX channel */ arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); /* Check the SMC call status, a0 of the result */ ret = (int)(res.a0 & 0xFFFFFFFF); if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING) return false; return true; } /* Always true for the response message in RX channel */ return true; } /** * zynqmp_ipi_send_data - Send data * * @chan: Channel Pointer * @data: Message Pointer * * Return: 0 if all goes good, else appropriate error messages. */ static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data) { struct device *dev = chan->mbox->dev; struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev); struct zynqmp_ipi_mchan *mchan = chan->con_priv; struct zynqmp_ipi_message *msg = data; u64 arg0; struct arm_smccc_res res; if (WARN_ON(!ipi_mbox)) { dev_err(dev, "no platform drv data??\n"); return -EINVAL; } if (mchan->chan_type == IPI_MB_CHNL_TX) { /* Send request message */ if (msg && msg->len > mchan->req_buf_size) { dev_err(dev, "channel %d message length %u > max %lu\n", mchan->chan_type, (unsigned int)msg->len, mchan->req_buf_size); return -EINVAL; } if (msg && msg->len) memcpy_toio(mchan->req_buf, msg->data, msg->len); /* Kick IPI mailbox to send message */ arg0 = SMC_IPI_MAILBOX_NOTIFY; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); } else { /* Send response message */ if (msg && msg->len > mchan->resp_buf_size) { dev_err(dev, "channel %d message length %u > max %lu\n", mchan->chan_type, (unsigned int)msg->len, mchan->resp_buf_size); return -EINVAL; } if (msg && msg->len) memcpy_toio(mchan->resp_buf, msg->data, msg->len); arg0 = SMC_IPI_MAILBOX_ACK; zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK, &res); } return 0; } /** * zynqmp_ipi_startup - Startup the IPI channel * * @chan: Channel pointer * * Return: 0 if all goes good, else return corresponding error message */ static int zynqmp_ipi_startup(struct mbox_chan *chan) { struct device *dev = chan->mbox->dev; struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev); struct zynqmp_ipi_mchan *mchan = chan->con_priv; u64 arg0; struct arm_smccc_res res; int ret = 0; unsigned int nchan_type; if (mchan->is_opened) return 0; /* If no channel has been opened, open the IPI mailbox */ nchan_type = (mchan->chan_type + 1) % 2; if (!ipi_mbox->mchans[nchan_type].is_opened) { arg0 = SMC_IPI_MAILBOX_OPEN; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); /* Check the SMC call status, a0 of the result */ ret = (int)(res.a0 & 0xFFFFFFFF); if (ret < 0) { dev_err(dev, "SMC to open the IPI channel failed.\n"); return ret; } ret = 0; } /* If it is RX channel, enable the IPI notification interrupt */ if (mchan->chan_type == IPI_MB_CHNL_RX) { arg0 = SMC_IPI_MAILBOX_ENABLE_IRQ; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); } mchan->is_opened = 1; return ret; } /** * zynqmp_ipi_shutdown - Shutdown the IPI channel * * @chan: Channel pointer */ static void zynqmp_ipi_shutdown(struct mbox_chan *chan) { struct device *dev = chan->mbox->dev; struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev); struct zynqmp_ipi_mchan *mchan = chan->con_priv; u64 arg0; struct arm_smccc_res res; unsigned int chan_type; if (!mchan->is_opened) return; /* If it is RX channel, disable notification interrupt */ chan_type = mchan->chan_type; if (chan_type == IPI_MB_CHNL_RX) { arg0 = SMC_IPI_MAILBOX_DISABLE_IRQ; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); } /* Release IPI mailbox if no other channel is opened */ chan_type = (chan_type + 1) % 2; if (!ipi_mbox->mchans[chan_type].is_opened) { arg0 = SMC_IPI_MAILBOX_RELEASE; zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res); } mchan->is_opened = 0; } /* ZynqMP IPI mailbox operations */ static const struct mbox_chan_ops zynqmp_ipi_chan_ops = { .startup = zynqmp_ipi_startup, .shutdown = zynqmp_ipi_shutdown, .peek_data = zynqmp_ipi_peek_data, .last_tx_done = zynqmp_ipi_last_tx_done, .send_data = zynqmp_ipi_send_data, }; /** * zynqmp_ipi_of_xlate - Translate of phandle to IPI mailbox channel * * @mbox: mailbox controller pointer * @p: phandle pointer * * Return: Mailbox channel, else return error pointer. */ static struct mbox_chan *zynqmp_ipi_of_xlate(struct mbox_controller *mbox, const struct of_phandle_args *p) { struct mbox_chan *chan; struct device *dev = mbox->dev; unsigned int chan_type; /* Only supports TX and RX channels */ chan_type = p->args[0]; if (chan_type != IPI_MB_CHNL_TX && chan_type != IPI_MB_CHNL_RX) { dev_err(dev, "req chnl failure: invalid chnl type %u.\n", chan_type); return ERR_PTR(-EINVAL); } chan = &mbox->chans[chan_type]; return chan; } static const struct of_device_id zynqmp_ipi_of_match[] = { { .compatible = "xlnx,zynqmp-ipi-mailbox" }, {}, }; MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match); /** * zynqmp_ipi_mbox_get_buf_res - Get buffer resource from the IPI dev node * * @node: IPI mbox device child node * @name: name of the IPI buffer * @res: pointer to where the resource information will be stored. * * Return: 0 for success, negative value for failure */ static int zynqmp_ipi_mbox_get_buf_res(struct device_node *node, const char *name, struct resource *res) { int ret, index; index = of_property_match_string(node, "reg-names", name); if (index >= 0) { ret = of_address_to_resource(node, index, res); if (ret < 0) return -EINVAL; return 0; } return -ENODEV; } /** * zynqmp_ipi_mbox_dev_release() - release the existence of a ipi mbox dev * * @dev: the ipi mailbox device * * This is to avoid the no device release() function kernel warning. * */ static void zynqmp_ipi_mbox_dev_release(struct device *dev) { (void)dev; } /** * zynqmp_ipi_mbox_probe - probe IPI mailbox resource from device node * * @ipi_mbox: pointer to IPI mailbox private data structure * @node: IPI mailbox device node * * Return: 0 for success, negative value for failure */ static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox, struct device_node *node) { struct zynqmp_ipi_mchan *mchan; struct mbox_chan *chans; struct mbox_controller *mbox; struct resource res; struct device *dev, *mdev; const char *name; int ret; dev = ipi_mbox->pdata->dev; /* Initialize dev for IPI mailbox */ ipi_mbox->dev.parent = dev; ipi_mbox->dev.release = NULL; ipi_mbox->dev.of_node = node; dev_set_name(&ipi_mbox->dev, "%s", of_node_full_name(node)); dev_set_drvdata(&ipi_mbox->dev, ipi_mbox); ipi_mbox->dev.release = zynqmp_ipi_mbox_dev_release; ipi_mbox->dev.driver = &zynqmp_ipi_mbox_driver; ret = device_register(&ipi_mbox->dev); if (ret) { dev_err(dev, "Failed to register ipi mbox dev.\n"); put_device(&ipi_mbox->dev); return ret; } mdev = &ipi_mbox->dev; mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX]; name = "local_request_region"; ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res); if (!ret) { mchan->req_buf_size = resource_size(&res); mchan->req_buf = devm_ioremap(mdev, res.start, mchan->req_buf_size); if (!mchan->req_buf) { dev_err(mdev, "Unable to map IPI buffer I/O memory\n"); return -ENOMEM; } } else if (ret != -ENODEV) { dev_err(mdev, "Unmatched resource %s, %d.\n", name, ret); return ret; } name = "remote_response_region"; ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res); if (!ret) { mchan->resp_buf_size = resource_size(&res); mchan->resp_buf = devm_ioremap(mdev, res.start, mchan->resp_buf_size); if (!mchan->resp_buf) { dev_err(mdev, "Unable to map IPI buffer I/O memory\n"); return -ENOMEM; } } else if (ret != -ENODEV) { dev_err(mdev, "Unmatched resource %s.\n", name); return ret; } mchan->rx_buf = devm_kzalloc(mdev, mchan->resp_buf_size + sizeof(struct zynqmp_ipi_message), GFP_KERNEL); if (!mchan->rx_buf) return -ENOMEM; mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX]; name = "remote_request_region"; ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res); if (!ret) { mchan->req_buf_size = resource_size(&res); mchan->req_buf = devm_ioremap(mdev, res.start, mchan->req_buf_size); if (!mchan->req_buf) { dev_err(mdev, "Unable to map IPI buffer I/O memory\n"); return -ENOMEM; } } else if (ret != -ENODEV) { dev_err(mdev, "Unmatched resource %s.\n", name); return ret; } name = "local_response_region"; ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res); if (!ret) { mchan->resp_buf_size = resource_size(&res); mchan->resp_buf = devm_ioremap(mdev, res.start, mchan->resp_buf_size); if (!mchan->resp_buf) { dev_err(mdev, "Unable to map IPI buffer I/O memory\n"); return -ENOMEM; } } else if (ret != -ENODEV) { dev_err(mdev, "Unmatched resource %s.\n", name); return ret; } mchan->rx_buf = devm_kzalloc(mdev, mchan->resp_buf_size + sizeof(struct zynqmp_ipi_message), GFP_KERNEL); if (!mchan->rx_buf) return -ENOMEM; /* Get the IPI remote agent ID */ ret = of_property_read_u32(node, "xlnx,ipi-id", &ipi_mbox->remote_id); if (ret < 0) { dev_err(dev, "No IPI remote ID is specified.\n"); return ret; } mbox = &ipi_mbox->mbox; mbox->dev = mdev; mbox->ops = &zynqmp_ipi_chan_ops; mbox->num_chans = 2; mbox->txdone_irq = false; mbox->txdone_poll = true; mbox->txpoll_period = 5; mbox->of_xlate = zynqmp_ipi_of_xlate; chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL); if (!chans) return -ENOMEM; mbox->chans = chans; chans[IPI_MB_CHNL_TX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_TX]; chans[IPI_MB_CHNL_RX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_RX]; ipi_mbox->mchans[IPI_MB_CHNL_TX].chan_type = IPI_MB_CHNL_TX; ipi_mbox->mchans[IPI_MB_CHNL_RX].chan_type = IPI_MB_CHNL_RX; ret = devm_mbox_controller_register(mdev, mbox); if (ret) dev_err(mdev, "Failed to register mbox_controller(%d)\n", ret); else dev_info(mdev, "Registered ZynqMP IPI mbox with TX/RX channels.\n"); return ret; } /** * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices * * @pdata: IPI private data */ static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata) { struct zynqmp_ipi_mbox *ipi_mbox; int i; i = pdata->num_mboxes; for (; i >= 0; i--) { ipi_mbox = &pdata->ipi_mboxes[i]; if (ipi_mbox->dev.parent) { mbox_controller_unregister(&ipi_mbox->mbox); if (device_is_registered(&ipi_mbox->dev)) device_unregister(&ipi_mbox->dev); } } } static int zynqmp_ipi_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *nc, *np = pdev->dev.of_node; struct zynqmp_ipi_pdata *pdata; struct zynqmp_ipi_mbox *mbox; int num_mboxes, ret = -EINVAL; num_mboxes = of_get_child_count(np); pdata = devm_kzalloc(dev, sizeof(*pdata) + (num_mboxes * sizeof(*mbox)), GFP_KERNEL); if (!pdata) return -ENOMEM; pdata->dev = dev; /* Get the IPI local agents ID */ ret = of_property_read_u32(np, "xlnx,ipi-id", &pdata->local_id); if (ret < 0) { dev_err(dev, "No IPI local ID is specified.\n"); return ret; } pdata->num_mboxes = num_mboxes; pdata->ipi_mboxes = (struct zynqmp_ipi_mbox *) ((char *)pdata + sizeof(*pdata)); mbox = pdata->ipi_mboxes; for_each_available_child_of_node(np, nc) { mbox->pdata = pdata; ret = zynqmp_ipi_mbox_probe(mbox, nc); if (ret) { dev_err(dev, "failed to probe subdev.\n"); ret = -EINVAL; goto free_mbox_dev; } mbox++; } /* IPI IRQ */ ret = platform_get_irq(pdev, 0); if (ret < 0) goto free_mbox_dev; pdata->irq = ret; ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt, IRQF_SHARED, dev_name(dev), pdata); if (ret) { dev_err(dev, "IRQ %d is not requested successfully.\n", pdata->irq); goto free_mbox_dev; } platform_set_drvdata(pdev, pdata); return ret; free_mbox_dev: zynqmp_ipi_free_mboxes(pdata); return ret; } static int zynqmp_ipi_remove(struct platform_device *pdev) { struct zynqmp_ipi_pdata *pdata; pdata = platform_get_drvdata(pdev); zynqmp_ipi_free_mboxes(pdata); return 0; } static struct platform_driver zynqmp_ipi_driver = { .probe = zynqmp_ipi_probe, .remove = zynqmp_ipi_remove, .driver = { .name = "zynqmp-ipi", .of_match_table = of_match_ptr(zynqmp_ipi_of_match), }, }; static int __init zynqmp_ipi_init(void) { return platform_driver_register(&zynqmp_ipi_driver); } subsys_initcall(zynqmp_ipi_init); static void __exit zynqmp_ipi_exit(void) { platform_driver_unregister(&zynqmp_ipi_driver); } module_exit(zynqmp_ipi_exit); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver"); MODULE_AUTHOR("Xilinx Inc.");