projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 5611fe48 BC |
1 | /* |
| 2 | * Servergy CTS-1000 Setup | |
| 3 | * | |
| 4 | * Maintained by Ben Collins <ben.c@servergy.com> | |
| 5 | * | |
| 6 | * Copyright 2012 by Servergy, Inc. | |
| 7 | * | |
| 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. | |
| 12 | */ | |
| 13 | ||
| 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> | |
| c11eede6 | 19 | #include <linux/of_irq.h> |
| 5611fe48 BC |
20 | #include <linux/workqueue.h> |
| 21 | #include <linux/reboot.h> | |
| 22 | #include <linux/interrupt.h> | |
| 23 | ||
| 24 | #include <asm/machdep.h> | |
| 25 | ||
| 26 | static struct device_node *halt_node; | |
| 27 | ||
| 28 | static struct of_device_id child_match[] = { | |
| 29 | { | |
| 30 | .compatible = "sgy,gpio-halt", | |
| 31 | }, | |
| 32 | {}, | |
| 33 | }; | |
| 34 | ||
| 35 | static void gpio_halt_wfn(struct work_struct *work) | |
| 36 | { | |
| 37 | /* Likely wont return */ | |
| 38 | orderly_poweroff(true); | |
| 39 | } | |
| 40 | static DECLARE_WORK(gpio_halt_wq, gpio_halt_wfn); | |
| 41 | ||
| 42 | static void gpio_halt_cb(void) | |
| 43 | { | |
| 44 | enum of_gpio_flags flags; | |
| 45 | int trigger, gpio; | |
| 46 | ||
| 47 | if (!halt_node) | |
| 48 | return; | |
| 49 | ||
| 50 | gpio = of_get_gpio_flags(halt_node, 0, &flags); | |
| 51 | ||
| 52 | if (!gpio_is_valid(gpio)) | |
| 53 | return; | |
| 54 | ||
| 55 | trigger = (flags == OF_GPIO_ACTIVE_LOW); | |
| 56 | ||
| 57 | printk(KERN_INFO "gpio-halt: triggering GPIO.\n"); | |
| 58 | ||
| 59 | /* Probably wont return */ | |
| 60 | gpio_set_value(gpio, trigger); | |
| 61 | } | |
| 62 | ||
| 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) | |
| 66 | { | |
| 67 | printk(KERN_INFO "gpio-halt: shutdown due to power button IRQ.\n"); | |
| 68 | schedule_work(&gpio_halt_wq); | |
| 69 | ||
| 70 | return IRQ_HANDLED; | |
| 71 | }; | |
| 72 | ||
| 9997d088 | 73 | static int gpio_halt_probe(struct platform_device *pdev) |
| 5611fe48 BC |
74 | { |
| 75 | enum of_gpio_flags flags; | |
| 76 | struct device_node *node = pdev->dev.of_node; | |
| 77 | int gpio, err, irq; | |
| 78 | int trigger; | |
| 79 | ||
| 80 | if (!node) | |
| 81 | return -ENODEV; | |
| 82 | ||
| 83 | /* If there's no matching child, this isn't really an error */ | |
| 84 | halt_node = of_find_matching_node(node, child_match); | |
| 85 | if (!halt_node) | |
| 86 | return 0; | |
| 87 | ||
| 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) | |
| 91 | return -EINVAL; | |
| 92 | ||
| 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)) | |
| 96 | return -EINVAL; | |
| 97 | ||
| 98 | err = gpio_request(gpio, "gpio-halt"); | |
| 99 | if (err) { | |
| 100 | printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n", | |
| 101 | gpio); | |
| 102 | halt_node = NULL; | |
| 103 | return err; | |
| 104 | } | |
| 105 | ||
| 106 | trigger = (flags == OF_GPIO_ACTIVE_LOW); | |
| 107 | ||
| 108 | gpio_direction_output(gpio, !trigger); | |
| 109 | ||
| 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); | |
| 114 | if (err) { | |
| 115 | printk(KERN_ERR "gpio-halt: error requesting IRQ %d for " | |
| 116 | "GPIO %d.\n", irq, gpio); | |
| 117 | gpio_free(gpio); | |
| 118 | halt_node = NULL; | |
| 119 | return err; | |
| 120 | } | |
| 121 | ||
| 122 | /* Register our halt function */ | |
| 123 | ppc_md.halt = gpio_halt_cb; | |
| 124 | ppc_md.power_off = gpio_halt_cb; | |
| 125 | ||
| 126 | printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" | |
| 127 | " irq).\n", gpio, trigger, irq); | |
| 128 | ||
| 129 | return 0; | |
| 130 | } | |
| 131 | ||
| 9997d088 | 132 | static int gpio_halt_remove(struct platform_device *pdev) |
| 5611fe48 BC |
133 | { |
| 134 | if (halt_node) { | |
| 135 | int gpio = of_get_gpio(halt_node, 0); | |
| 136 | int irq = irq_of_parse_and_map(halt_node, 0); | |
| 137 | ||
| 138 | free_irq(irq, halt_node); | |
| 139 | ||
| 140 | ppc_md.halt = NULL; | |
| 141 | ppc_md.power_off = NULL; | |
| 142 | ||
| 143 | gpio_free(gpio); | |
| 144 | ||
| 145 | halt_node = NULL; | |
| 146 | } | |
| 147 | ||
| 148 | return 0; | |
| 149 | } | |
| 150 | ||
| 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. */ | |
| 155 | { | |
| 156 | .compatible = "fsl,qoriq-gpio", | |
| 157 | }, | |
| 158 | {}, | |
| 159 | }; | |
| 160 | MODULE_DEVICE_TABLE(of, gpio_halt_match); | |
| 161 | ||
| 162 | static struct platform_driver gpio_halt_driver = { | |
| 163 | .driver = { | |
| 164 | .name = "gpio-halt", | |
| 165 | .owner = THIS_MODULE, | |
| 166 | .of_match_table = gpio_halt_match, | |
| 167 | }, | |
| 168 | .probe = gpio_halt_probe, | |
| 9997d088 | 169 | .remove = gpio_halt_remove, |
| 5611fe48 BC |
170 | }; |
| 171 | ||
| 172 | module_platform_driver(gpio_halt_driver); | |
| 173 | ||
| 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"); |