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authorSagar Dharia <sdharia@codeaurora.org>2017-12-11 23:42:58 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-19 11:01:02 +0100
commit46a2bb5a7f7ea2728be50f8f5b29a20267f700fe (patch)
tree593f156be08b9ac363e5f10d9db6e12cae8a7ea3 /drivers/slimbus/core.c
parent3648e78ec701843ff8fab461071ba05067274f26 (diff)
slimbus: core: Add slim controllers support
This patch adds support to slim controllers in the slim core, including some utility functions invoked by the controller and slim device drivers. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviwed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/slimbus/core.c')
-rw-r--r--drivers/slimbus/core.c306
1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/slimbus/core.c b/drivers/slimbus/core.c
index 02f5075a9309..ed53ae6bd1cc 100644
--- a/drivers/slimbus/core.c
+++ b/drivers/slimbus/core.c
@@ -7,7 +7,11 @@
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
+#include <linux/idr.h>
#include <linux/slimbus.h>
+#include "slimbus.h"
+
+static DEFINE_IDA(ctrl_ida);
static const struct slim_device_id *slim_match(const struct slim_device_id *id,
const struct slim_device *sbdev)
@@ -92,6 +96,308 @@ void slim_driver_unregister(struct slim_driver *drv)
}
EXPORT_SYMBOL_GPL(slim_driver_unregister);
+static void slim_dev_release(struct device *dev)
+{
+ struct slim_device *sbdev = to_slim_device(dev);
+
+ kfree(sbdev);
+}
+
+static int slim_add_device(struct slim_controller *ctrl,
+ struct slim_device *sbdev,
+ struct device_node *node)
+{
+ sbdev->dev.bus = &slimbus_bus;
+ sbdev->dev.parent = ctrl->dev;
+ sbdev->dev.release = slim_dev_release;
+ sbdev->dev.driver = NULL;
+ sbdev->ctrl = ctrl;
+
+ dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
+ sbdev->e_addr.manf_id,
+ sbdev->e_addr.prod_code,
+ sbdev->e_addr.dev_index,
+ sbdev->e_addr.instance);
+
+ return device_register(&sbdev->dev);
+}
+
+static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
+ struct slim_eaddr *eaddr,
+ struct device_node *node)
+{
+ struct slim_device *sbdev;
+ int ret;
+
+ sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
+ if (!sbdev)
+ return NULL;
+
+ sbdev->e_addr = *eaddr;
+ ret = slim_add_device(ctrl, sbdev, node);
+ if (ret) {
+ kfree(sbdev);
+ return NULL;
+ }
+
+ return sbdev;
+}
+
+/*
+ * slim_register_controller() - Controller bring-up and registration.
+ *
+ * @ctrl: Controller to be registered.
+ *
+ * A controller is registered with the framework using this API.
+ * If devices on a controller were registered before controller,
+ * this will make sure that they get probed when controller is up
+ */
+int slim_register_controller(struct slim_controller *ctrl)
+{
+ int id;
+
+ id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ ctrl->id = id;
+
+ if (!ctrl->min_cg)
+ ctrl->min_cg = SLIM_MIN_CLK_GEAR;
+ if (!ctrl->max_cg)
+ ctrl->max_cg = SLIM_MAX_CLK_GEAR;
+
+ ida_init(&ctrl->laddr_ida);
+ idr_init(&ctrl->tid_idr);
+ mutex_init(&ctrl->lock);
+
+ dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
+ ctrl->name, ctrl->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(slim_register_controller);
+
+/* slim_remove_device: Remove the effect of slim_add_device() */
+static void slim_remove_device(struct slim_device *sbdev)
+{
+ device_unregister(&sbdev->dev);
+}
+
+static int slim_ctrl_remove_device(struct device *dev, void *null)
+{
+ slim_remove_device(to_slim_device(dev));
+ return 0;
+}
+
+/**
+ * slim_unregister_controller() - Controller tear-down.
+ *
+ * @ctrl: Controller to tear-down.
+ */
+int slim_unregister_controller(struct slim_controller *ctrl)
+{
+ /* Remove all clients */
+ device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
+ ida_simple_remove(&ctrl_ida, ctrl->id);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(slim_unregister_controller);
+
+static void slim_device_update_status(struct slim_device *sbdev,
+ enum slim_device_status status)
+{
+ struct slim_driver *sbdrv;
+
+ if (sbdev->status == status)
+ return;
+
+ sbdev->status = status;
+ if (!sbdev->dev.driver)
+ return;
+
+ sbdrv = to_slim_driver(sbdev->dev.driver);
+ if (sbdrv->device_status)
+ sbdrv->device_status(sbdev, sbdev->status);
+}
+
+/**
+ * slim_report_absent() - Controller calls this function when a device
+ * reports absent, OR when the device cannot be communicated with
+ *
+ * @sbdev: Device that cannot be reached, or sent report absent
+ */
+void slim_report_absent(struct slim_device *sbdev)
+{
+ struct slim_controller *ctrl = sbdev->ctrl;
+
+ if (!ctrl)
+ return;
+
+ /* invalidate logical addresses */
+ mutex_lock(&ctrl->lock);
+ sbdev->is_laddr_valid = false;
+ mutex_unlock(&ctrl->lock);
+
+ ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
+ slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
+}
+EXPORT_SYMBOL_GPL(slim_report_absent);
+
+static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
+{
+ return (a->manf_id == b->manf_id &&
+ a->prod_code == b->prod_code &&
+ a->dev_index == b->dev_index &&
+ a->instance == b->instance);
+}
+
+static int slim_match_dev(struct device *dev, void *data)
+{
+ struct slim_eaddr *e_addr = data;
+ struct slim_device *sbdev = to_slim_device(dev);
+
+ return slim_eaddr_equal(&sbdev->e_addr, e_addr);
+}
+
+static struct slim_device *find_slim_device(struct slim_controller *ctrl,
+ struct slim_eaddr *eaddr)
+{
+ struct slim_device *sbdev;
+ struct device *dev;
+
+ dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
+ if (dev) {
+ sbdev = to_slim_device(dev);
+ return sbdev;
+ }
+
+ return NULL;
+}
+
+/**
+ * slim_get_device() - get handle to a device.
+ *
+ * @ctrl: Controller on which this device will be added/queried
+ * @e_addr: Enumeration address of the device to be queried
+ *
+ * Return: pointer to a device if it has already reported. Creates a new
+ * device and returns pointer to it if the device has not yet enumerated.
+ */
+struct slim_device *slim_get_device(struct slim_controller *ctrl,
+ struct slim_eaddr *e_addr)
+{
+ struct slim_device *sbdev;
+
+ sbdev = find_slim_device(ctrl, e_addr);
+ if (!sbdev) {
+ sbdev = slim_alloc_device(ctrl, e_addr, NULL);
+ if (!sbdev)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return sbdev;
+}
+EXPORT_SYMBOL_GPL(slim_get_device);
+
+static int slim_device_alloc_laddr(struct slim_device *sbdev,
+ bool report_present)
+{
+ struct slim_controller *ctrl = sbdev->ctrl;
+ u8 laddr;
+ int ret;
+
+ mutex_lock(&ctrl->lock);
+ if (ctrl->get_laddr) {
+ ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
+ if (ret < 0)
+ goto err;
+ } else if (report_present) {
+ ret = ida_simple_get(&ctrl->laddr_ida,
+ 0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
+ if (ret < 0)
+ goto err;
+
+ laddr = ret;
+ } else {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (ctrl->set_laddr) {
+ ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
+ if (ret) {
+ ret = -EINVAL;
+ goto err;
+ }
+ }
+
+ sbdev->laddr = laddr;
+ sbdev->is_laddr_valid = true;
+
+ slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
+
+ dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
+ laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
+ sbdev->e_addr.dev_index, sbdev->e_addr.instance);
+
+err:
+ mutex_unlock(&ctrl->lock);
+ return ret;
+
+}
+
+/**
+ * slim_device_report_present() - Report enumerated device.
+ *
+ * @ctrl: Controller with which device is enumerated.
+ * @e_addr: Enumeration address of the device.
+ * @laddr: Return logical address (if valid flag is false)
+ *
+ * Called by controller in response to REPORT_PRESENT. Framework will assign
+ * a logical address to this enumeration address.
+ * Function returns -EXFULL to indicate that all logical addresses are already
+ * taken.
+ */
+int slim_device_report_present(struct slim_controller *ctrl,
+ struct slim_eaddr *e_addr, u8 *laddr)
+{
+ struct slim_device *sbdev;
+ int ret;
+
+ sbdev = slim_get_device(ctrl, e_addr);
+ if (IS_ERR(sbdev))
+ return -ENODEV;
+
+ if (sbdev->is_laddr_valid) {
+ *laddr = sbdev->laddr;
+ return 0;
+ }
+
+ ret = slim_device_alloc_laddr(sbdev, true);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(slim_device_report_present);
+
+/**
+ * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
+ *
+ * @sbdev: client handle requesting the address.
+ *
+ * Return: zero if a logical address is valid or a new logical address
+ * has been assigned. error code in case of error.
+ */
+int slim_get_logical_addr(struct slim_device *sbdev)
+{
+ if (!sbdev->is_laddr_valid)
+ return slim_device_alloc_laddr(sbdev, false);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(slim_get_logical_addr);
+
static void __exit slimbus_exit(void)
{
bus_unregister(&slimbus_bus);