@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
# Core functionality
-peci-y := core.o
+peci-y := core.o request.o device.o
obj-$(CONFIG_PECI) += peci.o
# Hardware specific bus drivers
@@ -29,6 +29,20 @@ struct device_type peci_controller_type = {
.release = peci_controller_dev_release,
};
+static int peci_controller_scan_devices(struct peci_controller *controller)
+{
+ int ret;
+ u8 addr;
+
+ for (addr = PECI_BASE_ADDR; addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX; addr++) {
+ ret = peci_device_create(controller, addr);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static struct peci_controller *peci_controller_alloc(struct device *dev,
struct peci_controller_ops *ops)
{
@@ -64,10 +78,23 @@ static struct peci_controller *peci_controller_alloc(struct device *dev,
return ERR_PTR(ret);
}
+static int unregister_child(struct device *dev, void *dummy)
+{
+ peci_device_destroy(to_peci_device(dev));
+
+ return 0;
+}
+
static void unregister_controller(void *_controller)
{
struct peci_controller *controller = _controller;
+ /*
+ * Detach any active PECI devices. This can't fail, thus we do not
+ * check the returned value.
+ */
+ device_for_each_child_reverse(&controller->dev, NULL, unregister_child);
+
device_unregister(&controller->dev);
fwnode_handle_put(controller->dev.fwnode);
@@ -113,6 +140,12 @@ struct peci_controller *devm_peci_controller_add(struct device *dev,
if (ret)
return ERR_PTR(ret);
+ /*
+ * Ignoring retval since failures during scan are non-critical for
+ * controller itself.
+ */
+ peci_controller_scan_devices(controller);
+
return controller;
err_fwnode:
new file mode 100644
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/peci.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static int peci_detect(struct peci_controller *controller, u8 addr)
+{
+ /*
+ * PECI Ping is a command encoded by tx_len = 0, rx_len = 0.
+ * We expect correct Write FCS if the device at the target address
+ * is able to respond.
+ */
+ struct peci_request req = { 0 };
+ int ret;
+
+ mutex_lock(&controller->bus_lock);
+ ret = controller->ops->xfer(controller, addr, &req);
+ mutex_unlock(&controller->bus_lock);
+
+ return ret;
+}
+
+static bool peci_addr_valid(u8 addr)
+{
+ return addr >= PECI_BASE_ADDR && addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX;
+}
+
+static int peci_dev_exists(struct device *dev, void *data)
+{
+ struct peci_device *device = to_peci_device(dev);
+ u8 *addr = data;
+
+ if (device->addr == *addr)
+ return -EBUSY;
+
+ return 0;
+}
+
+int peci_device_create(struct peci_controller *controller, u8 addr)
+{
+ struct peci_device *device;
+ int ret;
+
+ if (!peci_addr_valid(addr))
+ return -EINVAL;
+
+ /* Check if we have already detected this device before. */
+ ret = device_for_each_child(&controller->dev, &addr, peci_dev_exists);
+ if (ret)
+ return 0;
+
+ ret = peci_detect(controller, addr);
+ if (ret) {
+ /*
+ * Device not present or host state doesn't allow successful
+ * detection at this time.
+ */
+ if (ret == -EIO || ret == -ETIMEDOUT)
+ return 0;
+
+ return ret;
+ }
+
+ device = kzalloc(sizeof(*device), GFP_KERNEL);
+ if (!device)
+ return -ENOMEM;
+
+ device_initialize(&device->dev);
+
+ device->addr = addr;
+ device->dev.parent = &controller->dev;
+ device->dev.bus = &peci_bus_type;
+ device->dev.type = &peci_device_type;
+
+ ret = dev_set_name(&device->dev, "%d-%02x", controller->id, device->addr);
+ if (ret)
+ goto err_put;
+
+ ret = device_add(&device->dev);
+ if (ret)
+ goto err_put;
+
+ return 0;
+
+err_put:
+ put_device(&device->dev);
+
+ return ret;
+}
+
+void peci_device_destroy(struct peci_device *device)
+{
+ bool killed;
+
+ device_lock(&device->dev);
+ killed = kill_device(&device->dev);
+ device_unlock(&device->dev);
+
+ if (!killed)
+ return;
+
+ device_unregister(&device->dev);
+}
+
+static void peci_device_release(struct device *dev)
+{
+ struct peci_device *device = to_peci_device(dev);
+
+ kfree(device);
+}
+
+struct device_type peci_device_type = {
+ .release = peci_device_release,
+};
@@ -8,6 +8,20 @@
#include <linux/types.h>
struct peci_controller;
+struct peci_device;
+struct peci_request;
+
+/* PECI CPU address range 0x30-0x37 */
+#define PECI_BASE_ADDR 0x30
+#define PECI_DEVICE_NUM_MAX 8
+
+struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len);
+void peci_request_free(struct peci_request *req);
+
+extern struct device_type peci_device_type;
+
+int peci_device_create(struct peci_controller *controller, u8 addr);
+void peci_device_destroy(struct peci_device *device);
extern struct bus_type peci_bus_type;
new file mode 100644
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Intel Corporation
+
+#include <linux/export.h>
+#include <linux/peci.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "internal.h"
+
+/**
+ * peci_request_alloc() - allocate &struct peci_requests
+ * @device: PECI device to which request is going to be sent
+ * @tx_len: TX length
+ * @rx_len: RX length
+ *
+ * Return: A pointer to a newly allocated &struct peci_request on success or NULL otherwise.
+ */
+struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len)
+{
+ struct peci_request *req;
+
+ /*
+ * TX and RX buffers are fixed length members of peci_request, this is
+ * just a warn for developers to make sure to expand the buffers (or
+ * change the allocation method) if we go over the current limit.
+ */
+ if (WARN_ON_ONCE(tx_len > PECI_REQUEST_MAX_BUF_SIZE || rx_len > PECI_REQUEST_MAX_BUF_SIZE))
+ return NULL;
+ /*
+ * PECI controllers that we are using now don't support DMA, this
+ * should be converted to DMA API once support for controllers that do
+ * allow it is added to avoid an extra copy.
+ */
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return NULL;
+
+ req->device = device;
+ req->tx.len = tx_len;
+ req->rx.len = rx_len;
+
+ return req;
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_alloc, PECI);
+
+/**
+ * peci_request_free() - free peci_request
+ * @req: the PECI request to be freed
+ */
+void peci_request_free(struct peci_request *req)
+{
+ kfree(req);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_free, PECI);