xref: /openbmc/linux/include/net/dsa.h (revision db181ce0)
1 /*
2  * include/net/dsa.h - Driver for Distributed Switch Architecture switch chips
3  * Copyright (c) 2008-2009 Marvell Semiconductor
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  */
10 
11 #ifndef __LINUX_NET_DSA_H
12 #define __LINUX_NET_DSA_H
13 
14 #include <linux/if_ether.h>
15 #include <linux/list.h>
16 #include <linux/timer.h>
17 #include <linux/workqueue.h>
18 
19 #define DSA_MAX_SWITCHES	4
20 #define DSA_MAX_PORTS		12
21 
22 struct dsa_chip_data {
23 	/*
24 	 * How to access the switch configuration registers.
25 	 */
26 	struct device	*mii_bus;
27 	int		sw_addr;
28 
29 	/*
30 	 * The names of the switch's ports.  Use "cpu" to
31 	 * designate the switch port that the cpu is connected to,
32 	 * "dsa" to indicate that this port is a DSA link to
33 	 * another switch, NULL to indicate the port is unused,
34 	 * or any other string to indicate this is a physical port.
35 	 */
36 	char		*port_names[DSA_MAX_PORTS];
37 
38 	/*
39 	 * An array (with nr_chips elements) of which element [a]
40 	 * indicates which port on this switch should be used to
41 	 * send packets to that are destined for switch a.  Can be
42 	 * NULL if there is only one switch chip.
43 	 */
44 	s8		*rtable;
45 };
46 
47 struct dsa_platform_data {
48 	/*
49 	 * Reference to a Linux network interface that connects
50 	 * to the root switch chip of the tree.
51 	 */
52 	struct device	*netdev;
53 
54 	/*
55 	 * Info structs describing each of the switch chips
56 	 * connected via this network interface.
57 	 */
58 	int		nr_chips;
59 	struct dsa_chip_data	*chip;
60 };
61 
62 struct dsa_switch_tree {
63 	/*
64 	 * Configuration data for the platform device that owns
65 	 * this dsa switch tree instance.
66 	 */
67 	struct dsa_platform_data	*pd;
68 
69 	/*
70 	 * Reference to network device to use, and which tagging
71 	 * protocol to use.
72 	 */
73 	struct net_device	*master_netdev;
74 	__be16			tag_protocol;
75 
76 	/*
77 	 * The switch and port to which the CPU is attached.
78 	 */
79 	s8			cpu_switch;
80 	s8			cpu_port;
81 
82 	/*
83 	 * Link state polling.
84 	 */
85 	int			link_poll_needed;
86 	struct work_struct	link_poll_work;
87 	struct timer_list	link_poll_timer;
88 
89 	/*
90 	 * Data for the individual switch chips.
91 	 */
92 	struct dsa_switch	*ds[DSA_MAX_SWITCHES];
93 };
94 
95 struct dsa_switch {
96 	/*
97 	 * Parent switch tree, and switch index.
98 	 */
99 	struct dsa_switch_tree	*dst;
100 	int			index;
101 
102 	/*
103 	 * Configuration data for this switch.
104 	 */
105 	struct dsa_chip_data	*pd;
106 
107 	/*
108 	 * The used switch driver.
109 	 */
110 	struct dsa_switch_driver	*drv;
111 
112 	/*
113 	 * Reference to mii bus to use.
114 	 */
115 	struct mii_bus		*master_mii_bus;
116 
117 	/*
118 	 * Slave mii_bus and devices for the individual ports.
119 	 */
120 	u32			dsa_port_mask;
121 	u32			phys_port_mask;
122 	struct mii_bus		*slave_mii_bus;
123 	struct net_device	*ports[DSA_MAX_PORTS];
124 };
125 
126 static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
127 {
128 	return !!(ds->index == ds->dst->cpu_switch && p == ds->dst->cpu_port);
129 }
130 
131 static inline u8 dsa_upstream_port(struct dsa_switch *ds)
132 {
133 	struct dsa_switch_tree *dst = ds->dst;
134 
135 	/*
136 	 * If this is the root switch (i.e. the switch that connects
137 	 * to the CPU), return the cpu port number on this switch.
138 	 * Else return the (DSA) port number that connects to the
139 	 * switch that is one hop closer to the cpu.
140 	 */
141 	if (dst->cpu_switch == ds->index)
142 		return dst->cpu_port;
143 	else
144 		return ds->pd->rtable[dst->cpu_switch];
145 }
146 
147 struct dsa_switch_driver {
148 	struct list_head	list;
149 
150 	__be16			tag_protocol;
151 	int			priv_size;
152 
153 	/*
154 	 * Probing and setup.
155 	 */
156 	char	*(*probe)(struct mii_bus *bus, int sw_addr);
157 	int	(*setup)(struct dsa_switch *ds);
158 	int	(*set_addr)(struct dsa_switch *ds, u8 *addr);
159 
160 	/*
161 	 * Access to the switch's PHY registers.
162 	 */
163 	int	(*phy_read)(struct dsa_switch *ds, int port, int regnum);
164 	int	(*phy_write)(struct dsa_switch *ds, int port,
165 			     int regnum, u16 val);
166 
167 	/*
168 	 * Link state polling and IRQ handling.
169 	 */
170 	void	(*poll_link)(struct dsa_switch *ds);
171 
172 	/*
173 	 * ethtool hardware statistics.
174 	 */
175 	void	(*get_strings)(struct dsa_switch *ds, int port, uint8_t *data);
176 	void	(*get_ethtool_stats)(struct dsa_switch *ds,
177 				     int port, uint64_t *data);
178 	int	(*get_sset_count)(struct dsa_switch *ds);
179 };
180 
181 void register_switch_driver(struct dsa_switch_driver *type);
182 void unregister_switch_driver(struct dsa_switch_driver *type);
183 
184 static inline void *ds_to_priv(struct dsa_switch *ds)
185 {
186 	return (void *)(ds + 1);
187 }
188 
189 /*
190  * The original DSA tag format and some other tag formats have no
191  * ethertype, which means that we need to add a little hack to the
192  * networking receive path to make sure that received frames get
193  * the right ->protocol assigned to them when one of those tag
194  * formats is in use.
195  */
196 static inline bool dsa_uses_dsa_tags(struct dsa_switch_tree *dst)
197 {
198 	return !!(dst->tag_protocol == htons(ETH_P_DSA));
199 }
200 
201 static inline bool dsa_uses_trailer_tags(struct dsa_switch_tree *dst)
202 {
203 	return !!(dst->tag_protocol == htons(ETH_P_TRAILER));
204 }
205 
206 #endif
207