1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Serial base bus layer for controllers |
4 | * |
5 | * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/ |
6 | * Author: Tony Lindgren <tony@atomide.com> |
7 | * |
8 | * The serial core bus manages the serial core controller instances. |
9 | */ |
10 | |
11 | #include <linux/container_of.h> |
12 | #include <linux/device.h> |
13 | #include <linux/idr.h> |
14 | #include <linux/module.h> |
15 | #include <linux/serial_core.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/spinlock.h> |
18 | |
19 | #include "serial_base.h" |
20 | |
21 | static bool serial_base_initialized; |
22 | |
23 | static const struct device_type serial_ctrl_type = { |
24 | .name = "ctrl" , |
25 | }; |
26 | |
27 | static const struct device_type serial_port_type = { |
28 | .name = "port" , |
29 | }; |
30 | |
31 | static int serial_base_match(struct device *dev, struct device_driver *drv) |
32 | { |
33 | if (dev->type == &serial_ctrl_type && |
34 | str_has_prefix(str: drv->name, prefix: serial_ctrl_type.name)) |
35 | return 1; |
36 | |
37 | if (dev->type == &serial_port_type && |
38 | str_has_prefix(str: drv->name, prefix: serial_port_type.name)) |
39 | return 1; |
40 | |
41 | return 0; |
42 | } |
43 | |
44 | static const struct bus_type serial_base_bus_type = { |
45 | .name = "serial-base" , |
46 | .match = serial_base_match, |
47 | }; |
48 | |
49 | int serial_base_driver_register(struct device_driver *driver) |
50 | { |
51 | driver->bus = &serial_base_bus_type; |
52 | |
53 | return driver_register(drv: driver); |
54 | } |
55 | |
56 | void serial_base_driver_unregister(struct device_driver *driver) |
57 | { |
58 | driver_unregister(drv: driver); |
59 | } |
60 | |
61 | static int serial_base_device_init(struct uart_port *port, |
62 | struct device *dev, |
63 | struct device *parent_dev, |
64 | const struct device_type *type, |
65 | void (*release)(struct device *dev), |
66 | unsigned int ctrl_id, |
67 | unsigned int port_id) |
68 | { |
69 | device_initialize(dev); |
70 | dev->type = type; |
71 | dev->parent = parent_dev; |
72 | dev->bus = &serial_base_bus_type; |
73 | dev->release = release; |
74 | |
75 | if (!serial_base_initialized) { |
76 | dev_dbg(port->dev, "uart_add_one_port() called before arch_initcall()?\n" ); |
77 | return -EPROBE_DEFER; |
78 | } |
79 | |
80 | if (type == &serial_ctrl_type) |
81 | return dev_set_name(dev, name: "%s:%d" , dev_name(dev: port->dev), ctrl_id); |
82 | |
83 | if (type == &serial_port_type) |
84 | return dev_set_name(dev, name: "%s:%d.%d" , dev_name(dev: port->dev), |
85 | ctrl_id, port_id); |
86 | |
87 | return -EINVAL; |
88 | } |
89 | |
90 | static void serial_base_ctrl_release(struct device *dev) |
91 | { |
92 | struct serial_ctrl_device *ctrl_dev = to_serial_base_ctrl_device(dev); |
93 | |
94 | kfree(objp: ctrl_dev); |
95 | } |
96 | |
97 | void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev) |
98 | { |
99 | if (!ctrl_dev) |
100 | return; |
101 | |
102 | device_del(dev: &ctrl_dev->dev); |
103 | put_device(dev: &ctrl_dev->dev); |
104 | } |
105 | |
106 | struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port, |
107 | struct device *parent) |
108 | { |
109 | struct serial_ctrl_device *ctrl_dev; |
110 | int err; |
111 | |
112 | ctrl_dev = kzalloc(size: sizeof(*ctrl_dev), GFP_KERNEL); |
113 | if (!ctrl_dev) |
114 | return ERR_PTR(error: -ENOMEM); |
115 | |
116 | ida_init(ida: &ctrl_dev->port_ida); |
117 | |
118 | err = serial_base_device_init(port, dev: &ctrl_dev->dev, |
119 | parent_dev: parent, type: &serial_ctrl_type, |
120 | release: serial_base_ctrl_release, |
121 | ctrl_id: port->ctrl_id, port_id: 0); |
122 | if (err) |
123 | goto err_put_device; |
124 | |
125 | err = device_add(dev: &ctrl_dev->dev); |
126 | if (err) |
127 | goto err_put_device; |
128 | |
129 | return ctrl_dev; |
130 | |
131 | err_put_device: |
132 | put_device(dev: &ctrl_dev->dev); |
133 | |
134 | return ERR_PTR(error: err); |
135 | } |
136 | |
137 | static void serial_base_port_release(struct device *dev) |
138 | { |
139 | struct serial_port_device *port_dev = to_serial_base_port_device(dev); |
140 | |
141 | kfree(objp: port_dev); |
142 | } |
143 | |
144 | struct serial_port_device *serial_base_port_add(struct uart_port *port, |
145 | struct serial_ctrl_device *ctrl_dev) |
146 | { |
147 | struct serial_port_device *port_dev; |
148 | int min = 0, max = -1; /* Use -1 for max to apply IDA defaults */ |
149 | int err; |
150 | |
151 | port_dev = kzalloc(size: sizeof(*port_dev), GFP_KERNEL); |
152 | if (!port_dev) |
153 | return ERR_PTR(error: -ENOMEM); |
154 | |
155 | /* Device driver specified port_id vs automatic assignment? */ |
156 | if (port->port_id) { |
157 | min = port->port_id; |
158 | max = port->port_id; |
159 | } |
160 | |
161 | err = ida_alloc_range(&ctrl_dev->port_ida, min, max, GFP_KERNEL); |
162 | if (err < 0) { |
163 | kfree(objp: port_dev); |
164 | return ERR_PTR(error: err); |
165 | } |
166 | |
167 | port->port_id = err; |
168 | |
169 | err = serial_base_device_init(port, dev: &port_dev->dev, |
170 | parent_dev: &ctrl_dev->dev, type: &serial_port_type, |
171 | release: serial_base_port_release, |
172 | ctrl_id: port->ctrl_id, port_id: port->port_id); |
173 | if (err) |
174 | goto err_put_device; |
175 | |
176 | port_dev->port = port; |
177 | |
178 | err = device_add(dev: &port_dev->dev); |
179 | if (err) |
180 | goto err_put_device; |
181 | |
182 | return port_dev; |
183 | |
184 | err_put_device: |
185 | put_device(dev: &port_dev->dev); |
186 | ida_free(&ctrl_dev->port_ida, id: port->port_id); |
187 | |
188 | return ERR_PTR(error: err); |
189 | } |
190 | |
191 | void serial_base_port_device_remove(struct serial_port_device *port_dev) |
192 | { |
193 | struct serial_ctrl_device *ctrl_dev; |
194 | struct device *parent; |
195 | |
196 | if (!port_dev) |
197 | return; |
198 | |
199 | parent = port_dev->dev.parent; |
200 | ctrl_dev = to_serial_base_ctrl_device(parent); |
201 | |
202 | device_del(dev: &port_dev->dev); |
203 | ida_free(&ctrl_dev->port_ida, id: port_dev->port->port_id); |
204 | put_device(dev: &port_dev->dev); |
205 | } |
206 | |
207 | static int serial_base_init(void) |
208 | { |
209 | int ret; |
210 | |
211 | ret = bus_register(bus: &serial_base_bus_type); |
212 | if (ret) |
213 | return ret; |
214 | |
215 | ret = serial_base_ctrl_init(); |
216 | if (ret) |
217 | goto err_bus_unregister; |
218 | |
219 | ret = serial_base_port_init(); |
220 | if (ret) |
221 | goto err_ctrl_exit; |
222 | |
223 | serial_base_initialized = true; |
224 | |
225 | return 0; |
226 | |
227 | err_ctrl_exit: |
228 | serial_base_ctrl_exit(); |
229 | |
230 | err_bus_unregister: |
231 | bus_unregister(bus: &serial_base_bus_type); |
232 | |
233 | return ret; |
234 | } |
235 | arch_initcall(serial_base_init); |
236 | |
237 | static void serial_base_exit(void) |
238 | { |
239 | serial_base_port_exit(); |
240 | serial_base_ctrl_exit(); |
241 | bus_unregister(bus: &serial_base_bus_type); |
242 | } |
243 | module_exit(serial_base_exit); |
244 | |
245 | MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>" ); |
246 | MODULE_DESCRIPTION("Serial core bus" ); |
247 | MODULE_LICENSE("GPL" ); |
248 | |