[PATCH v10 1/7] i3c: master: master initialization flow document

Parshuram Thombare
2020-11-30T06:18:06Z

Document describing master initialization, mastership handover
and DEFSLVS handling processes.

Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
---
Documentation/driver-api/i3c/index.rst | 1 +
.../driver-api/i3c/master-initialization-flow.rst | 187 ++++++++++++++++++++
2 files changed, 188 insertions(+), 0 deletions(-)
create mode 100644 Documentation/driver-api/i3c/master-initialization-flow.rst

diff --git a/Documentation/driver-api/i3c/index.rst b/Documentation/driver-api/i3c/index.rst
index 783d6da..604f1c5 100644
--- a/Documentation/driver-api/i3c/index.rst
+++ b/Documentation/driver-api/i3c/index.rst
@@ -9,3 +9,4 @@ I3C subsystem
protocol
device-driver-api
master-driver-api
+ master-initialization-flow
diff --git a/Documentation/driver-api/i3c/master-initialization-flow.rst b/Documentation/driver-api/i3c/master-initialization-flow.rst
new file mode 100644
index 0000000..e02b90d
--- /dev/null
+++ b/Documentation/driver-api/i3c/master-initialization-flow.rst
@@ -0,0 +1,187 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+I3C Master Initialization Flow
+==============================
+
+.. kernel-render:: DOT
+ :alt: I3C Master Initialization digraph
+ :caption: I3C Master Initialization Flow
+
+ digraph master_init {
+ ranksep=.25; size="35,35";
+ subgraph cluster_0 {
+ style=dashed
+ x0[shape=ellipse, label="I3C driver probe", style="filled"]
+ x1[shape=diamond, label="Secondary Master ?"]
+ a1[shape=box, label="Do I3C master controller specific initialization"]
+ b1[shape=box, label="Do I3C master controller specific initialization,\n
+ except enabling the DEFSLVS interrupt."]
+ a2[shape=box, label="Call i3c_primary_master_register"]
+ b2[shape=box, label="Call i3c_secondary_master_register"]
+ x0->x1;
+ x1->a1[label="No"];
+ x1->b1[label="Yes"];
+ a1->a2; b1->b2;
+ }
+
+ subgraph cluster_1 {
+ style=dashed
+ label="Current Master";
+ a3[shape=ellipse, label="i3c_primary_master_register", style="filled"]
+ a4[shape=box, label="Initialize I3C master controller object."]
+ a5[shape=box, label="Create I2C objects for devices in DTS and add to I2C list."]
+ a6[shape=box, label="Set appropriate bus mode based on I2C devices information."]
+ a7[shape=box, label="Create a work queue."]
+ a8[shape=box, label="Call i3c_primary_master_bus_init"]
+ a19[shape=box, label="Add I3C object representing this master to the system."]
+ a20[shape=box, label="Expose our I3C bus as an I2C adapter so that I2C devices\n
+ are exposed through the I2C subsystem."]
+ a21[shape=box, label="Register all I3C devices."]
+ a22[shape=box, label="Broadcast ENEC MR, HJ message."]
+ a3->a4->a5->a6->a7->a8; a19->a20->a21->a22;
+ a8->a19[style="invisible"];
+ }
+
+ subgraph cluster_2 {
+ style=dashed
+ label="Current Master";
+ a9[shape=ellipse, label="i3c_primary_master_bus_init", style="filled"]
+ a10[shape=box, label="Call bus_init to do controller specific bus initialization\n
+ and enabling the controller."]
+ a11[shape=box, label="Create I3C object representing the master and add it to\n
+ the I3C device list."]
+ a12[shape=box, label="Set current master to the object created to represent I3C\n
+ master device."]
+ a13[shape=box, label="Reset all dynamic address that may have been assigned before."]
+ a14[shape=box, label="Disable all slave events before starting DAA."]
+ a15[shape=box, label="Pre-assign dynamic address and retrieve device information."]
+ a16[shape=box, label="Do dynamic address assignment to all I3C devices currenly\n
+ present on the bus."]
+ a17[shape=box, label="Create I3C objects representing devices found during DAA."]
+ a18[shape=box, label="Send DEFSVLS message containing information about all\n
+ known I3C and I2C devices."]
+ a9->a10->a11->a12->a13->a14->a15->a16->a17->a18;
+ }
+
+ subgraph cluster_3 {
+ style=dashed
+ label="Current Master";
+ h1[shape=ellipse, label="MR request interrupt", style="filled"]
+ h2[shape=box, label="Bottom half i3c_master_yield_bus"]
+ h1->h2;
+ }
+
+ subgraph cluster_4 {
+ style=dashed
+ label="Current Master";
+ i1[shape=ellipse, label="i3c_master_yield_bus", style="filled"]
+ i2[shape=box, label="Check if this device is still a master to handle a case of\n
+ multiple MR requests from different devices at a same time."]
+ i3[shape=box, label="Broadcast DISEC MR, HJ message.\n
+ New master should broadcast ENEC MR, HJ once its usage of bus is done."]
+ i4[shape=box, label="Get accept mastership acknowldege from requesting master."]
+ i5[shape=box, label="In case of failure reenable MR requests by broadcasting ENEC MR, HJ."]
+ i6[shape=box, label="Mastership hand over is done."]
+ i1->i2->i3->i4->i5->i6;
+ }
+
+ subgraph cluster_5 {
+ style=dashed
+ b3[shape=ellipse, label="i3c_secondary_master_register", style="filled"]
+ b4[shape=box, label="Initialize I3C master controller object."]
+ b5[shape=box, label="Create I2C objects for devices in DTS and add to I2C list."]
+ b6[shape=box, label="Set appropriate bus mode based on I2C devices information."]
+ b7[shape=box, label="Create a work queue."]
+ b8[shape=box, label="Call i3c_secondary_master_bus_init."]
+ b12[shape=box, label="Allocate memory for defslvs_data, that will be used to pass I3C\n
+ device list received in DEFSLVS to the I3C core DEFSLVS processing."]
+ b13[shape=box, label="Add I3C object representing this master to the system."]
+ b14[shape=box, label="Expose our I3C bus as an I2C adapter so that I2C devices are\n
+ exposed through the I2C subsystem."]
+ b3->b4->b5->b6->b7->b8; b12->b13->b14;
+ b8->b12[style="invisible"]
+ }
+
+ subgraph cluster_6 {
+ style=dashed
+ b9[shape=ellipse, label="i3c_secondary_master_bus_init", style="filled"]
+ b10[shape=box, label="Call bus_init to do controller specific bus initialization\n
+ and enabling the controller."]
+ b11[shape=box, label="Create I3C object representing the master and add it to\n
+ the I3C device list."]
+ b9->b10->b11;
+ }
+
+ subgraph cluster_7 {
+ style=dashed
+ d1[shape=ellipse, label="DEFSLVS interrupt", style="filled"]
+ d2[shape=box, label="Controller driver can chose how to handle I2C devices received\n
+ in DEFSLVS."]
+ d3[shape=box, label="Read all I3C devices information from DEFSLVS message\n
+ to defslvs_data structure in the master object."]
+ d4[shape=box, label="Call i3c_master_process_defslvs."]
+ d1->d2->d3->d4;
+ }
+
+ subgraph cluster_8 {
+ style=dashed
+ d5[shape=ellipse, label="i3c_master_process_defslvs", style="filled"]
+ d6[shape=box, label="Acquire I3C bus mastership."]
+ d7[shape=diamond, label="Bus acquired ?"]
+ d8[shape=box, label="Handle I3C device list from DEFSLVS."]
+ d9[shape=box, label="Call i3c_master_populate_bus"]
+ d10[shape=box, label="Queue defslvs processing task for retry."]
+ d5->d6;
+ d7->d8[label="Yes"];
+ d8->d9;
+ d7->d10[label="No"];
+ d6->d7[style="invisible"];
+ d10->d5[style="dotted", constraint=false];
+ }
+
+ subgraph cluster_9 {
+ style=dashed
+ e1[shape=ellipse, label="i3c_master_acquire_bus", style="filled"]
+ e2[shape=box, label="If device is already holding the mastership,\n
+ just broadcast DISEC MR, HJ message and return success."]
+ e3[shape=box, label="Call request_mastership method"]
+ e1->e2->e3;
+ }
+
+ subgraph cluster_10 {
+ style=dashed
+ f1[shape=ellipse, label="request_mastership", style="filled"]
+ f2[shape=box, label="Return success if device is already in master mode."]
+ f3[shape=box, label="Return error if device don't have dyn_addr."]
+ f4[shape=box, label="Return error if MR requests are disabled by current master."]
+ f5[shape=box, label="Send MR request"]
+ f6[shape=box, label="Wait with timeout until MR_DONE interrupt is received."]
+ f1->f2->f3->f4->f5->f6;
+ }
+
+ subgraph cluster_11 {
+ style=dashed
+ g1[shape=ellipse, label="i3c_master_populate_bus", style="filled"]
+ g2[shape=box, label="Free up all I3C addresses to handle address\n
+ re assignment by main master."]
+ g3[shape=box, label="Master acquire dyn_addr received from the driver."]
+ g4[shape=box, label="For every I3C device in the defslvs_data\n
+ call i3c_master_add_i3c_dev_locked."]
+ g1->g2->g3->g4;
+ }
+
+ a2->a3; a8->a9; a18->a19;
+ b2->b3; b8->b9; b11->b12;
+ b14->d1[style=invisible];
+ a22->h1[style=invisible];
+ d4->d5;
+ d6->e1;
+ e3->f1;
+ f6->d7[constraint=false];
+ h2->i1;
+ d9->g1;
+ a18->d1[style="dotted", constraint=false];
+ f5->h1[style="dotted", constraint=false];
+ i4->f6[style="dotted", constraint=false];
+ }
--
1.7.1