2 * Servergy CTS-1000 Setup
4 * Maintained by Ben Collins <ben.c@servergy.com>
6 * Copyright 2012 by Servergy, Inc.
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
14 #include <linux/platform_device.h>
15 #include <linux/device.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/of_gpio.h>
19 #include <linux/of_irq.h>
20 #include <linux/workqueue.h>
21 #include <linux/reboot.h>
22 #include <linux/interrupt.h>
24 #include <asm/machdep.h>
26 static struct device_node *halt_node;
28 static struct of_device_id child_match[] = {
30 .compatible = "sgy,gpio-halt",
35 static void gpio_halt_wfn(struct work_struct *work)
37 /* Likely wont return */
38 orderly_poweroff(true);
40 static DECLARE_WORK(gpio_halt_wq, gpio_halt_wfn);
42 static void gpio_halt_cb(void)
44 enum of_gpio_flags flags;
50 gpio = of_get_gpio_flags(halt_node, 0, &flags);
52 if (!gpio_is_valid(gpio))
55 trigger = (flags == OF_GPIO_ACTIVE_LOW);
57 printk(KERN_INFO "gpio-halt: triggering GPIO.\n");
59 /* Probably wont return */
60 gpio_set_value(gpio, trigger);
63 /* This IRQ means someone pressed the power button and it is waiting for us
64 * to handle the shutdown/poweroff. */
65 static irqreturn_t gpio_halt_irq(int irq, void *__data)
67 printk(KERN_INFO "gpio-halt: shutdown due to power button IRQ.\n");
68 schedule_work(&gpio_halt_wq);
73 static int gpio_halt_probe(struct platform_device *pdev)
75 enum of_gpio_flags flags;
76 struct device_node *node = pdev->dev.of_node;
83 /* If there's no matching child, this isn't really an error */
84 halt_node = of_find_matching_node(node, child_match);
88 /* Technically we could just read the first one, but punish
89 * DT writers for invalid form. */
90 if (of_gpio_count(halt_node) != 1)
93 /* Get the gpio number relative to the dynamic base. */
94 gpio = of_get_gpio_flags(halt_node, 0, &flags);
95 if (!gpio_is_valid(gpio))
98 err = gpio_request(gpio, "gpio-halt");
100 printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n",
106 trigger = (flags == OF_GPIO_ACTIVE_LOW);
108 gpio_direction_output(gpio, !trigger);
110 /* Now get the IRQ which tells us when the power button is hit */
111 irq = irq_of_parse_and_map(halt_node, 0);
112 err = request_irq(irq, gpio_halt_irq, IRQF_TRIGGER_RISING |
113 IRQF_TRIGGER_FALLING, "gpio-halt", halt_node);
115 printk(KERN_ERR "gpio-halt: error requesting IRQ %d for "
116 "GPIO %d.\n", irq, gpio);
122 /* Register our halt function */
123 ppc_md.halt = gpio_halt_cb;
124 ppc_md.power_off = gpio_halt_cb;
126 printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d"
127 " irq).\n", gpio, trigger, irq);
132 static int gpio_halt_remove(struct platform_device *pdev)
135 int gpio = of_get_gpio(halt_node, 0);
136 int irq = irq_of_parse_and_map(halt_node, 0);
138 free_irq(irq, halt_node);
141 ppc_md.power_off = NULL;
151 static struct of_device_id gpio_halt_match[] = {
152 /* We match on the gpio bus itself and scan the children since they
153 * wont be matched against us. We know the bus wont match until it
154 * has been registered too. */
156 .compatible = "fsl,qoriq-gpio",
160 MODULE_DEVICE_TABLE(of, gpio_halt_match);
162 static struct platform_driver gpio_halt_driver = {
165 .owner = THIS_MODULE,
166 .of_match_table = gpio_halt_match,
168 .probe = gpio_halt_probe,
169 .remove = gpio_halt_remove,
172 module_platform_driver(gpio_halt_driver);
174 MODULE_DESCRIPTION("Driver to support GPIO triggered system halt for Servergy CTS-1000 Systems.");
175 MODULE_VERSION("1.0");
176 MODULE_AUTHOR("Ben Collins <ben.c@servergy.com>");
177 MODULE_LICENSE("GPL");