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 */
 43struct 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
 54extern void msp_restart(char *);
 55
 56static 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
 70static void softreset_release(void *data)
 71{
 72	printk(KERN_WARNING "SOFTRESET switch was released\n");
 73
 74	/* Do nothing */
 75}
 76
 77static 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
 84static 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
 92static 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
102static 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
113static 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
137static 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
156static 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
165subsys_initcall(msp_hwbutton_setup);