[PATCH v7 5/7] i3c: master: add defslvs processing

Parshuram Thombare
2020-05-11T13:15:40Z

Added defslvs processing code to the I3C master subsystem.

Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
---
drivers/i3c/master.c | 142 ++++++++++++++++++++++++++++++++++++-
include/linux/i3c/master.h | 7 ++
2 files changed, 147 insertions(+), 2 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 9c8250a6a2b0..ea53fadeed99 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2639,7 +2639,8 @@ static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops)
return -EINVAL;

if (ops->request_mastership &&
- (!ops->enable_mr_events || !ops->check_event_set))
+ (!ops->enable_mr_events || !ops->check_event_set ||
+ !ops->sec_mst_dyn_addr))
return -EINVAL;

return 0;
@@ -2818,12 +2819,20 @@ int i3c_secondary_master_register(struct i3c_master_controller *master,
struct device *parent,
const struct i3c_master_controller_ops *ops)
{
- int ret;
+ int ret, sz;

ret = i3c_master_init(master, parent, ops, true);
if (ret)
return ret;

+ sz = sizeof(struct i3c_ccc_dev_desc) * I3C_BUS_MAX_DEVS;
+ master->defslvs_data.devs = devm_kzalloc(&master->dev, sz,
+ GFP_KERNEL);
+ if (!master->defslvs_data.devs) {
+ ret = -ENOMEM;
+ goto err_cleanup_bus;
+ }
+
ret = device_add(&master->dev);
if (ret)
goto err_cleanup_bus;
@@ -2856,6 +2865,135 @@ int i3c_secondary_master_register(struct i3c_master_controller *master,
}
EXPORT_SYMBOL_GPL(i3c_secondary_master_register);

+static int i3c_master_populate_bus(struct i3c_master_controller *master)
+{
+ struct i3c_dev_desc *i3cdev, *olddev, *tmp;
+ struct i3c_ccc_dev_desc *desc;
+ struct list_head i3c_old;
+ struct i3c_bus *i3cbus;
+ int slot, dyn_addr, ret;
+
+ i3cbus = i3c_master_get_bus(master);
+
+ INIT_LIST_HEAD(&i3c_old);
+ list_for_each_entry_safe(olddev, tmp, &i3cbus->devs.i3c, common.node) {
+ i3c_master_put_i3c_addrs(olddev);
+ list_del(&olddev->common.node);
+ list_add(&olddev->common.node, &i3c_old);
+ }
+
+ dyn_addr = master->ops->sec_mst_dyn_addr(master);
+ master->this->info.dyn_addr = dyn_addr;
+ i3c_master_get_i3c_addrs(master->this);
+ list_del(&master->this->common.node);
+ list_add(&master->this->common.node, &i3cbus->devs.i3c);
+
+ desc = master->defslvs_data.devs;
+ for (slot = 0; slot < master->defslvs_data.ndevs; slot++, desc++) {
+ struct i3c_device_info info = {
+ .dyn_addr = desc->dyn_addr
+ };
+
+ if (dyn_addr == info.dyn_addr)
+ continue;
+
+ i3cdev = i3c_master_alloc_i3c_dev(master, &info);
+ if (IS_ERR(i3cdev)) {
+ ret = PTR_ERR(i3cdev);
+ goto populate_bus_fail;
+ }
+
+ i3c_master_get_i3c_addrs(i3cdev);
+ ret = i3c_master_retrieve_dev_info(i3cdev);
+ i3c_master_put_i3c_addrs(i3cdev);
+ if (ret) {
+ i3c_master_free_i3c_dev(i3cdev);
+ goto populate_bus_fail;
+ }
+
+ list_for_each_entry_safe(olddev, tmp, &i3c_old, common.node) {
+ if (olddev->info.pid == i3cdev->info.pid) {
+ olddev->info.dyn_addr = info.dyn_addr;
+ i3c_master_get_i3c_addrs(olddev);
+ list_del(&olddev->common.node);
+ list_add(&olddev->common.node,
+ &i3cbus->devs.i3c);
+ i3c_master_free_i3c_dev(i3cdev);
+ i3cdev = NULL;
+ break;
+ }
+ }
+
+ if (i3cdev) {
+ ret = i3c_master_attach_i3c_dev(master, i3cdev);
+ if (ret) {
+ i3c_master_free_i3c_dev(i3cdev);
+ goto populate_bus_fail;
+ }
+ }
+ }
+
+ list_for_each_entry_safe(olddev, tmp, &i3c_old, common.node) {
+ if (olddev->dev) {
+ olddev->dev->desc = NULL;
+ if (device_is_registered(&olddev->dev->dev))
+ device_unregister(&olddev->dev->dev);
+ else
+ put_device(&olddev->dev->dev);
+ kfree(olddev->dev);
+ }
+ list_del(&olddev->common.node);
+ i3c_master_free_i3c_dev(olddev);
+ }
+
+ return 0;
+
+populate_bus_fail:
+ /*
+ * Try to restore i3cbus->devs.i3c list, so far no i3c
+ * device is deleted, only moved or added to the original
+ * i3c list. Move rest of the i3c devices from old list,
+ * to correctly process defslvs in rety.
+ */
+ list_for_each_entry_safe(olddev, tmp, &i3c_old, common.node) {
+ list_del(&olddev->common.node);
+ list_add(&olddev->common.node, &i3cbus->devs.i3c);
+ }
+
+ return ret;
+}
+
+/**
+ * i3c_master_process_defslvs() - process I3C device list received in
+ * DEFSLVS for device plug/unplug and address change.
+ * @m: I3C master object
+ *
+ * This function may sleep, so should not be called in the atomic context.
+ */
+int i3c_master_process_defslvs(struct i3c_master_controller *m)
+{
+ int ret;
+
+ i3c_bus_normaluse_lock(&m->bus);
+ ret = i3c_master_acquire_bus(m);
+ i3c_bus_normaluse_unlock(&m->bus);
+ if (ret)
+ return ret;
+
+ i3c_bus_maintenance_lock(&m->bus);
+ ret = i3c_master_populate_bus(m);
+ i3c_bus_maintenance_unlock(&m->bus);
+ if (!ret) {
+ i3c_bus_normaluse_lock(&m->bus);
+ i3c_master_register_new_i3c_devs(m);
+ i3c_bus_normaluse_unlock(&m->bus);
+ }
+ i3c_master_enable_mr_events(m);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_master_process_defslvs);
+
/**
* i3c_master_unregister() - unregister an I3C master
* @master: master used to send frames on the bus
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index dd67497ad8b1..688487c4a62a 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -488,6 +488,8 @@ struct i3c_master_controller_ops {
* in a thread context. Typical examples are Hot Join processing which
* requires taking the bus lock in maintenance, which in turn, can only
* be done from a sleep-able context
+ * @defslvs_data: list used to pass i3c device list received in DEFSLVS message,
+ * from DEFSLVS controller driver to I3C core
*
* A &struct i3c_master_controller has to be registered to the I3C subsystem
* through i3c_master_register(). None of &struct i3c_master_controller fields
@@ -507,6 +509,10 @@ struct i3c_master_controller {
} boardinfo;
struct i3c_bus bus;
struct workqueue_struct *wq;
+ struct {
+ u32 ndevs;
+ struct i3c_ccc_dev_desc *devs;
+ } defslvs_data;
};

/**
@@ -533,6 +539,7 @@ struct i3c_master_controller {

void i3c_master_yield_bus(struct i3c_master_controller *m,
u8 sec_mst_dyn_addr);
+int i3c_master_process_defslvs(struct i3c_master_controller *m);
int i3c_master_do_i2c_xfers(struct i3c_master_controller *master,
const struct i2c_msg *xfers,
int nxfers);
--
2.17.1