1 /*
2 * HP Human Interface Loop Master Link Controller driver.
3 *
4 * Copyright (c) 2001 Brian S. Julin
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer,
12 * without modification.
13 * 2. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * Alternatively, this software may be distributed under the terms of the
17 * GNU General Public License ("GPL").
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 *
29 * References:
30 * HP-HIL Technical Reference Manual. Hewlett Packard Product No. 45918A
31 *
32 */
33
34 #include <linux/hil.h>
35 #include <linux/time.h>
36 #include <linux/interrupt.h>
37 #include <linux/semaphore.h>
38 #include <linux/serio.h>
39 #include <linux/list.h>
40
41 typedef struct hil_mlc hil_mlc;
42
43 /* The HIL has a complicated state engine.
44 * We define the structure of nodes in the state engine here.
45 */
46 enum hilse_act {
47 /* HILSE_OUT prepares to receive input if the next node
48 * is an IN or EXPECT, and then sends the given packet.
49 */
50 HILSE_OUT = 0,
51
52 /* HILSE_CTS checks if the loop is busy. */
53 HILSE_CTS,
54
55 /* HILSE_OUT_LAST sends the given command packet to
56 * the last configured/running device on the loop.
57 */
58 HILSE_OUT_LAST,
59
60 /* HILSE_OUT_DISC sends the given command packet to
61 * the next device past the last configured/running one.
62 */
63 HILSE_OUT_DISC,
64
65 /* HILSE_FUNC runs a callback function with given arguments.
66 * a positive return value causes the "ugly" branch to be taken.
67 */
68 HILSE_FUNC,
69
70 /* HILSE_IN simply expects any non-errored packet to arrive
71 * within arg usecs.
72 */
73 HILSE_IN = 0x100,
74
75 /* HILSE_EXPECT expects a particular packet to arrive
76 * within arg usecs, any other packet is considered an error.
77 */
78 HILSE_EXPECT,
79
80 /* HILSE_EXPECT_LAST as above but dev field should be last
81 * discovered/operational device.
82 */
83 HILSE_EXPECT_LAST,
84
85 /* HILSE_EXPECT_LAST as above but dev field should be first
86 * undiscovered/inoperational device.
87 */
88 HILSE_EXPECT_DISC
89 };
90
91 typedef int (hilse_func) (hil_mlc *mlc, int arg);
92 struct hilse_node {
93 enum hilse_act act; /* How to process this node */
94 union {
95 hilse_func *func; /* Function to call if HILSE_FUNC */
96 hil_packet packet; /* Packet to send or to compare */
97 } object;
98 int arg; /* Timeout in usec or parm for func */
99 int good; /* Node to jump to on success */
100 int bad; /* Node to jump to on error */
101 int ugly; /* Node to jump to on timeout */
102 };
103
104 /* Methods for back-end drivers, e.g. hp_sdc_mlc */
105 typedef int (hil_mlc_cts) (hil_mlc *mlc);
106 typedef void (hil_mlc_out) (hil_mlc *mlc);
107 typedef int (hil_mlc_in) (hil_mlc *mlc, suseconds_t timeout);
108
109 struct hil_mlc_devinfo {
110 uint8_t idd[16]; /* Device ID Byte and Describe Record */
111 uint8_t rsc[16]; /* Security Code Header and Record */
112 uint8_t exd[16]; /* Extended Describe Record */
113 uint8_t rnm[16]; /* Device name as returned by RNM command */
114 };
115
116 struct hil_mlc_serio_map {
117 hil_mlc *mlc;
118 int di_revmap;
119 int didx;
120 };
121
122 /* How many (possibly old/detached) devices the we try to keep track of */
123 #define HIL_MLC_DEVMEM 16
124
125 struct hil_mlc {
126 struct list_head list; /* hil_mlc is organized as linked list */
127
128 rwlock_t lock;
129
130 void *priv; /* Data specific to a particular type of MLC */
131
132 int seidx; /* Current node in state engine */
133 int istarted, ostarted;
134
135 hil_mlc_cts *cts;
136 struct semaphore csem; /* Raised when loop idle */
137
138 hil_mlc_out *out;
139 struct semaphore osem; /* Raised when outpacket dispatched */
140 hil_packet opacket;
141
142 hil_mlc_in *in;
143 struct semaphore isem; /* Raised when a packet arrives */
144 hil_packet ipacket[16];
145 hil_packet imatch;
146 int icount;
147 unsigned long instart;
148 unsigned long intimeout;
149
150 int ddi; /* Last operational device id */
151 int lcv; /* LCV to throttle loops */
152 time64_t lcv_time; /* Time loop was started */
153
154 int di_map[7]; /* Maps below items to live devs */
155 struct hil_mlc_devinfo di[HIL_MLC_DEVMEM];
156 struct serio *serio[HIL_MLC_DEVMEM];
157 struct hil_mlc_serio_map serio_map[HIL_MLC_DEVMEM];
158 hil_packet serio_opacket[HIL_MLC_DEVMEM];
159 int serio_oidx[HIL_MLC_DEVMEM];
160 struct hil_mlc_devinfo di_scratch; /* Temporary area */
161
162 int opercnt;
163
164 struct tasklet_struct *tasklet;
165 };
166
167 int hil_mlc_register(hil_mlc *mlc);
168 int hil_mlc_unregister(hil_mlc *mlc);