[PATH v7 1/2] mailbox: ZynqMP IPI mailbox controller

From: Wendy Liang
Date: Thu Dec 20 2018 - 12:33:03 EST


This patch is to introduce ZynqMP IPI mailbox controller driver
to use the ZynqMP IPI block as mailboxes.

Signed-off-by: Wendy Liang <wendy.liang@xxxxxxxxxx>
---
drivers/mailbox/Kconfig | 11 +
drivers/mailbox/Makefile | 2 +
drivers/mailbox/zynqmp-ipi-mailbox.c | 764 +++++++++++++++++++++++++++++++++++
3 files changed, 777 insertions(+)
create mode 100644 drivers/mailbox/zynqmp-ipi-mailbox.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 3eeb12e9..d86e7a4 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -205,4 +205,15 @@ config MTK_CMDQ_MBOX
mailbox driver. The CMDQ is used to help read/write registers with
critical time limitation, such as updating display configuration
during the vblank.
+
+config ZYNQMP_IPI_MBOX
+ bool "Xilinx ZynqMP IPI Mailbox"
+ depends on ARCH_ZYNQMP && OF
+ help
+ Say yes here to add support for Xilinx IPI mailbox driver.
+ This mailbox driver is used to send notification or short message
+ between processors with Xilinx ZynqMP IPI. It will place the
+ message to the IPI buffer and will access the IPI control
+ registers to kick the other processor or enquire status.
+
endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index c818b5d..8be3bcb 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -44,3 +44,5 @@ obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o
obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o

obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
+
+obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o
diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
new file mode 100644
index 0000000..bbddfd5
--- /dev/null
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -0,0 +1,764 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Inter Processor Interrupt(IPI) Mailbox Driver
+ *
+ * Copyright (C) 2018 Xilinx, Inc.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/zynqmp-ipi-message.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+/* 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_OPEN_IRQ_MASK 0x00000001UL /* IRQ enable bit in IPI
+ * open SMC call
+ */
+#define IPI_SMC_NOTIFY_BLOCK_MASK 0x00000001UL /* Flag to indicate if
+ * IPI notification needs
+ * to be blocking.
+ */
+#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,
+ unsigned long a4, unsigned long a5,
+ unsigned long a6, unsigned long a7,
+ 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, a4, a5, a6, a7, res);
+ else
+ arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, 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, 0, 0, 0, 0, &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, 0, 0, 0, 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;
+ struct zynqmp_ipi_message *msg;
+
+ 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, 0, 0, 0, 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;
+
+ msg = mchan->rx_buf;
+ msg->len = mchan->resp_buf_size;
+ memcpy_fromio(msg->data, mchan->resp_buf, msg->len);
+ mbox_chan_received_data(chan, (void *)msg);
+ 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;
+ u32 timeout;
+ int ret;
+
+ 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;
+ }
+ /* Enquire if the mailbox is free to send message */
+ arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
+ timeout = 10;
+ if (msg && msg->len) {
+ timeout = 10;
+ do {
+ zynqmp_ipi_fw_call(ipi_mbox, arg0,
+ 0, 0, 0, 0, 0, &res);
+ ret = res.a0 & 0xFFFFFFFF;
+ if (ret >= 0 &&
+ !(ret & IPI_MB_STATUS_SEND_PENDING))
+ break;
+ usleep_range(1, 2);
+ timeout--;
+ } while (timeout);
+ if (!timeout) {
+ dev_warn(dev, "chan %d sending msg timeout.\n",
+ ipi_mbox->remote_id);
+ return -ETIME;
+ }
+ 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, 0, 0, 0, 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_NOTIFY;
+ arg0 = SMC_IPI_MAILBOX_ACK;
+ zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
+ 0, 0, 0, 0, &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, 0, 0, 0, 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, 0, 0, 0, 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, 0, 0, 0, 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, 0, 0, 0, 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");
+ 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 (IS_ERR(mchan->req_buf)) {
+ dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+ ret = PTR_ERR(mchan->req_buf);
+ return ret;
+ }
+ } 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 (IS_ERR(mchan->resp_buf)) {
+ dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+ ret = PTR_ERR(mchan->resp_buf);
+ return ret;
+ }
+ } 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 (IS_ERR(mchan->req_buf)) {
+ dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+ ret = PTR_ERR(mchan->req_buf);
+ return ret;
+ }
+ } 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 (IS_ERR(mchan->resp_buf)) {
+ dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+ ret = PTR_ERR(mchan->resp_buf);
+ return ret;
+ }
+ } 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 = mbox_controller_register(mbox);
+ if (ret)
+ dev_err(mdev,
+ "Failed to register mbox_controller(%d)\n", ret);
+ else
+ dev_info(mdev, "Probed ZynqMP IPI Mailbox driver.\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);
+ 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 i, ret = -EINVAL;
+
+ i = 0;
+ for_each_available_child_of_node(np, nc)
+ i++;
+ pdata = devm_kzalloc(dev, sizeof(*pdata) + (i * 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 = i;
+ 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) {
+ dev_err(dev, "unable to find IPI IRQ.\n");
+ 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.");
--
2.7.4