1 /*
2 * Sets up interrupt handlers for various hardware switches which are
3 * connected to interrupt lines.
4 *
5 * Copyright 2005-2207 PMC-Sierra, Inc.
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 *
12 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
13 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
15 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
16 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
17 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
18 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
19 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
20 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
21 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22 *
23 * You should have received a copy of the GNU General Public License along
24 * with this program; if not, write to the Free Software Foundation, Inc.,
25 * 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31
32 #include <msp_int.h>
33 #include <msp_regs.h>
34 #include <msp_regops.h>
35
36 /* For hwbutton_interrupt->initial_state */
37 #define HWBUTTON_HI 0x1
38 #define HWBUTTON_LO 0x2
39
40 /*
41 * This struct describes a hardware button
42 */
43 struct hwbutton_interrupt {
44 char *name; /* Name of button */
45 int irq; /* Actual LINUX IRQ */
46 int eirq; /* Extended IRQ number (0-7) */
47 int initial_state; /* The "normal" state of the switch */
48 void (*handle_hi)(void *); /* Handler: switch input has gone HI */
49 void (*handle_lo)(void *); /* Handler: switch input has gone LO */
50 void *data; /* Optional data to pass to handler */
51 };
52
53 #ifdef CONFIG_PMC_MSP7120_GW
54 extern void msp_restart(char *);
55
56 static void softreset_push(void *data)
57 {
58 printk(KERN_WARNING "SOFTRESET switch was pushed\n");
59
60 /*
61 * In the future you could move this to the release handler,
62 * timing the difference between the 'push' and 'release', and only
63 * doing this ungraceful restart if the button has been down for
64 * a certain amount of time; otherwise doing a graceful restart.
65 */
66
67 msp_restart(NULL);
68 }
69
70 static void softreset_release(void *data)
71 {
72 printk(KERN_WARNING "SOFTRESET switch was released\n");
73
74 /* Do nothing */
75 }
76
77 static void standby_on(void *data)
78 {
79 printk(KERN_WARNING "STANDBY switch was set to ON (not implemented)\n");
80
81 /* TODO: Put board in standby mode */
82 }
83
84 static void standby_off(void *data)
85 {
86 printk(KERN_WARNING
87 "STANDBY switch was set to OFF (not implemented)\n");
88
89 /* TODO: Take out of standby mode */
90 }
91
92 static struct hwbutton_interrupt softreset_sw = {
93 .name = "Softreset button",
94 .irq = MSP_INT_EXT0,
95 .eirq = 0,
96 .initial_state = HWBUTTON_HI,
97 .handle_hi = softreset_release,
98 .handle_lo = softreset_push,
99 .data = NULL,
100 };
101
102 static struct hwbutton_interrupt standby_sw = {
103 .name = "Standby switch",
104 .irq = MSP_INT_EXT1,
105 .eirq = 1,
106 .initial_state = HWBUTTON_HI,
107 .handle_hi = standby_off,
108 .handle_lo = standby_on,
109 .data = NULL,
110 };
111 #endif /* CONFIG_PMC_MSP7120_GW */
112
113 static irqreturn_t hwbutton_handler(int irq, void *data)
114 {
115 struct hwbutton_interrupt *hirq = data;
116 unsigned long cic_ext = *CIC_EXT_CFG_REG;
117
118 if (CIC_EXT_IS_ACTIVE_HI(cic_ext, hirq->eirq)) {
119 /* Interrupt: pin is now HI */
120 CIC_EXT_SET_ACTIVE_LO(cic_ext, hirq->eirq);
121 hirq->handle_hi(hirq->data);
122 } else {
123 /* Interrupt: pin is now LO */
124 CIC_EXT_SET_ACTIVE_HI(cic_ext, hirq->eirq);
125 hirq->handle_lo(hirq->data);
126 }
127
128 /*
129 * Invert the POLARITY of this level interrupt to ack the interrupt
130 * Thus next state change will invoke the opposite message
131 */
132 *CIC_EXT_CFG_REG = cic_ext;
133
134 return IRQ_HANDLED;
135 }
136
137 static int msp_hwbutton_register(struct hwbutton_interrupt *hirq)
138 {
139 unsigned long cic_ext;
140
141 if (hirq->handle_hi == NULL || hirq->handle_lo == NULL)
142 return -EINVAL;
143
144 cic_ext = *CIC_EXT_CFG_REG;
145 CIC_EXT_SET_TRIGGER_LEVEL(cic_ext, hirq->eirq);
146 if (hirq->initial_state == HWBUTTON_HI)
147 CIC_EXT_SET_ACTIVE_LO(cic_ext, hirq->eirq);
148 else
149 CIC_EXT_SET_ACTIVE_HI(cic_ext, hirq->eirq);
150 *CIC_EXT_CFG_REG = cic_ext;
151
152 return request_irq(hirq->irq, hwbutton_handler, 0,
153 hirq->name, hirq);
154 }
155
156 static int __init msp_hwbutton_setup(void)
157 {
158 #ifdef CONFIG_PMC_MSP7120_GW
159 msp_hwbutton_register(&softreset_sw);
160 msp_hwbutton_register(&standby_sw);
161 #endif
162 return 0;
163 }
164
165 subsys_initcall(msp_hwbutton_setup);