mailbox: zynqmp: support mulitple mboxes via device-tree

As of now only one mailbox agent is supported by mailbox driver.
On zynqmp platform there are about 7 mailbox agents which can communicate
over same IPI channel to U-Boot. This patch series introduces new
"zynqmp_ipi_dest" driver which adds one to multi-channel mailbox
support.

Following format in device-tree is expected as per latest bindings:
zynqmp-ipi {
	compatible = "xlnx,zynqmp-ipi-mailbox";

	mbox_1: mailbox@1 {
		/* New compatible for child node */
		compatible = "xlnx,zynqmp-ipi-dest-mailbox";
		...
	};

	...

	mbox_n: mailbox@n {
		compatible = "xlnx,zynqmp-ipi-dest-mailbox";
		...
	}
};

Then mailbox client uses child mailbox node as following:

ipi-dest-1 {
	...
	mboxes = <mbox_1 0>, <mbox_1 1>;
	mbox-names = "tx", "rx";
	...
};

New "zynqmp_ipi_dest" driver is for devices with
"xlnx,zynqmp-ipi-dest-mailbox" compatible string. This driver will take care
of mailbox send recv ops and it replaces previous "zynqmp_ipi" driver.
Now "zynqmp_ipi" driver simply binds each child device with "zynqmp_ipi_dest"
driver.

However, its important to maintain backward comaptibility with previous
bindings where child node does not have compatible string. In such case, new
driver isn't probed by U-Boot during boot and system fails to boot. To
resolve this issue firmware-zynqmp.c driver probes all the IPI parent node
driver which binds each child node device with "zynqmp_ipi_dest" driver.

This makes sure corresponding child driver will be
probed when requested using mbox_get_by_name or mbox_get_by_idx
framework calls.

This way multiple mailbox agents are supported in device-tree without breaking
previous binding support.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Link: https://lore.kernel.org/r/20231204215620.63334-4-tanmay.shah@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

diff --git a/drivers/firmware/firmware-zynqmp.c b/drivers/firmware/firmware-zynqmp.c
index 8ea15c7ed3390c40351817a68ac769cff75ceaff..dfad798a2e7d93b3d93038f7b2cde1bdcce08a67 100644 (file)
--- a/drivers/firmware/firmware-zynqmp.c
+++ b/drivers/firmware/firmware-zynqmp.c
@@ -8,6 +8,7 @@
 #include <common.h>
 #include <cpu_func.h>
 #include <dm.h>
+#include <dm/device_compat.h>
 #include <dm/lists.h>
 #include <log.h>
 #include <zynqmp_firmware.h>
@@ -290,10 +291,31 @@ int zynqmp_pmufw_load_config_object(const void *cfg_obj, size_t size)
 
 static int zynqmp_power_probe(struct udevice *dev)
 {
+       struct udevice *ipi_dev;
+       ofnode ipi_node;
        int ret;
 
        debug("%s, (dev=%p)\n", __func__, dev);
 
+       /*
+        * Probe all IPI parent node driver. It is important to have IPI
+        * devices available when requested by mbox_get_by* API.
+        * If IPI device isn't available, then mailbox request fails and
+        * that causes system boot failure.
+        * To avoid this make sure all IPI parent drivers are probed here,
+        * and IPI parent driver binds each child node to mailbox driver.
+        * This way mbox_get_by_* API will have correct mailbox device
+        * driver probed.
+        */
+       ofnode_for_each_compatible_node(ipi_node, "xlnx,zynqmp-ipi-mailbox") {
+               ret = uclass_get_device_by_ofnode(UCLASS_NOP, ipi_node, &ipi_dev);
+               if (ret) {
+                       dev_err(dev, "failed to get IPI device from node %s\n",
+                               ofnode_get_name(ipi_node));
+                       return ret;
+               }
+       }
+
        ret = mbox_get_by_name(dev, "tx", &zynqmp_power.tx_chan);
        if (ret) {
                debug("%s: Cannot find tx mailbox\n", __func__);

diff --git a/drivers/mailbox/zynqmp-ipi.c b/drivers/mailbox/zynqmp-ipi.c
index e76561f310278cb0b9bde013749a2fab15221cd8..eb86847bbe2354e0bfda3d4551e64066ec9c3f38 100644 (file)
--- a/drivers/mailbox/zynqmp-ipi.c
+++ b/drivers/mailbox/zynqmp-ipi.c
@@ -12,6 +12,7 @@
 #include <dm.h>
 #include <mailbox-uclass.h>
 #include <dm/device_compat.h>
+#include <dm/lists.h>
 #include <dm/of_access.h>
 #include <linux/arm-smccc.h>
 #include <linux/ioport.h>
@@ -157,7 +158,7 @@ static int zynqmp_ipi_recv(struct mbox_chan *chan, void *data)
        return ret;
 };
 
-static int zynqmp_ipi_probe(struct udevice *dev)
+static int zynqmp_ipi_dest_probe(struct udevice *dev)
 {
        struct zynqmp_ipi *zynqmp = dev_get_priv(dev);
        struct resource res;
@@ -166,14 +167,12 @@ static int zynqmp_ipi_probe(struct udevice *dev)
 
        debug("%s(dev=%p)\n", __func__, dev);
 
+       node = dev_ofnode(dev);
+
        if (IS_ENABLED(CONFIG_SPL_BUILD) || of_machine_is_compatible("xlnx,zynqmp"))
                zynqmp->el3_supported = true;
 
-       /* Get subnode where the regs are defined */
-       /* Note IPI mailbox node needs to be the first one in DT */
-       node = ofnode_first_subnode(dev_ofnode(dev));
-
-       ret = dev_read_u32(dev, "xlnx,ipi-id", &zynqmp->local_id);
+       ret = dev_read_u32(dev->parent, "xlnx,ipi-id", &zynqmp->local_id);
        if (ret) {
                dev_err(dev, "can't get local ipi id\n");
                return ret;
@@ -191,6 +190,8 @@ static int zynqmp_ipi_probe(struct udevice *dev)
        };
        zynqmp->local_req_regs = devm_ioremap(dev, res.start,
                                              (res.start - res.end));
+       if (!zynqmp->local_req_regs)
+               return -EINVAL;
 
        if (ofnode_read_resource_byname(node, "local_response_region", &res)) {
                dev_err(dev, "No reg property for local_response_region\n");
@@ -198,6 +199,8 @@ static int zynqmp_ipi_probe(struct udevice *dev)
        };
        zynqmp->local_res_regs = devm_ioremap(dev, res.start,
                                              (res.start - res.end));
+       if (!zynqmp->local_res_regs)
+               return -EINVAL;
 
        if (ofnode_read_resource_byname(node, "remote_request_region", &res)) {
                dev_err(dev, "No reg property for remote_request_region\n");
@@ -205,6 +208,8 @@ static int zynqmp_ipi_probe(struct udevice *dev)
        };
        zynqmp->remote_req_regs = devm_ioremap(dev, res.start,
                                               (res.start - res.end));
+       if (!zynqmp->remote_req_regs)
+               return -EINVAL;
 
        if (ofnode_read_resource_byname(node, "remote_response_region", &res)) {
                dev_err(dev, "No reg property for remote_response_region\n");
@@ -212,25 +217,59 @@ static int zynqmp_ipi_probe(struct udevice *dev)
        };
        zynqmp->remote_res_regs = devm_ioremap(dev, res.start,
                                               (res.start - res.end));
+       if (!zynqmp->remote_res_regs)
+               return -EINVAL;
 
        return 0;
 };
 
-static const struct udevice_id zynqmp_ipi_ids[] = {
-       { .compatible = "xlnx,zynqmp-ipi-mailbox" },
-       { }
+static int zynqmp_ipi_probe(struct udevice *dev)
+{
+       struct udevice *cdev;
+       ofnode cnode;
+       int ret;
+
+       debug("%s(dev=%p)\n", __func__, dev);
+
+       dev_for_each_subnode(cnode, dev) {
+               ret = device_bind_driver_to_node(dev, "zynqmp_ipi_dest",
+                                                ofnode_get_name(cnode),
+                                                cnode, &cdev);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
 };
 
-struct mbox_ops zynqmp_ipi_mbox_ops = {
+struct mbox_ops zynqmp_ipi_dest_mbox_ops = {
        .send = zynqmp_ipi_send,
        .recv = zynqmp_ipi_recv,
 };
 
+static const struct udevice_id zynqmp_ipi_dest_ids[] = {
+       { .compatible = "xlnx,zynqmp-ipi-dest-mailbox" },
+       { }
+};
+
+U_BOOT_DRIVER(zynqmp_ipi_dest) = {
+       .name = "zynqmp_ipi_dest",
+       .id = UCLASS_MAILBOX,
+       .of_match = zynqmp_ipi_dest_ids,
+       .probe = zynqmp_ipi_dest_probe,
+       .priv_auto = sizeof(struct zynqmp_ipi),
+       .ops = &zynqmp_ipi_dest_mbox_ops,
+};
+
+static const struct udevice_id zynqmp_ipi_ids[] = {
+       { .compatible = "xlnx,zynqmp-ipi-mailbox" },
+       { }
+};
+
 U_BOOT_DRIVER(zynqmp_ipi) = {
        .name = "zynqmp_ipi",
-       .id = UCLASS_MAILBOX,
+       .id = UCLASS_NOP,
        .of_match = zynqmp_ipi_ids,
        .probe = zynqmp_ipi_probe,
-       .priv_auto      = sizeof(struct zynqmp_ipi),
-       .ops = &zynqmp_ipi_mbox_ops,
+       .flags = DM_FLAG_PROBE_AFTER_BIND,
 };