diff options
Diffstat (limited to 'arch/powerpc/platforms/85xx/sgy_cts1000.c')
| -rw-r--r-- | arch/powerpc/platforms/85xx/sgy_cts1000.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c new file mode 100644 index 000000000..21d6aaa5c --- /dev/null +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c @@ -0,0 +1,177 @@ +/* + * Servergy CTS-1000 Setup + * + * Maintained by Ben Collins <ben.c@servergy.com> + * + * Copyright 2012 by Servergy, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/platform_device.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/of_gpio.h> +#include <linux/of_irq.h> +#include <linux/workqueue.h> +#include <linux/reboot.h> +#include <linux/interrupt.h> + +#include <asm/machdep.h> + +static struct device_node *halt_node; + +static const struct of_device_id child_match[] = { + { + .compatible = "sgy,gpio-halt", + }, + {}, +}; + +static void gpio_halt_wfn(struct work_struct *work) +{ + /* Likely wont return */ + orderly_poweroff(true); +} +static DECLARE_WORK(gpio_halt_wq, gpio_halt_wfn); + +static void __noreturn gpio_halt_cb(void) +{ + enum of_gpio_flags flags; + int trigger, gpio; + + if (!halt_node) + panic("No reset GPIO information was provided in DT\n"); + + gpio = of_get_gpio_flags(halt_node, 0, &flags); + + if (!gpio_is_valid(gpio)) + panic("Provided GPIO is invalid\n"); + + trigger = (flags == OF_GPIO_ACTIVE_LOW); + + printk(KERN_INFO "gpio-halt: triggering GPIO.\n"); + + /* Probably wont return */ + gpio_set_value(gpio, trigger); + + panic("Halt failed\n"); +} + +/* This IRQ means someone pressed the power button and it is waiting for us + * to handle the shutdown/poweroff. */ +static irqreturn_t gpio_halt_irq(int irq, void *__data) +{ + printk(KERN_INFO "gpio-halt: shutdown due to power button IRQ.\n"); + schedule_work(&gpio_halt_wq); + + return IRQ_HANDLED; +}; + +static int gpio_halt_probe(struct platform_device *pdev) +{ + enum of_gpio_flags flags; + struct device_node *node = pdev->dev.of_node; + int gpio, err, irq; + int trigger; + + if (!node) + return -ENODEV; + + /* If there's no matching child, this isn't really an error */ + halt_node = of_find_matching_node(node, child_match); + if (!halt_node) + return 0; + + /* Technically we could just read the first one, but punish + * DT writers for invalid form. */ + if (of_gpio_count(halt_node) != 1) + return -EINVAL; + + /* Get the gpio number relative to the dynamic base. */ + gpio = of_get_gpio_flags(halt_node, 0, &flags); + if (!gpio_is_valid(gpio)) + return -EINVAL; + + err = gpio_request(gpio, "gpio-halt"); + if (err) { + printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n", + gpio); + halt_node = NULL; + return err; + } + + trigger = (flags == OF_GPIO_ACTIVE_LOW); + + gpio_direction_output(gpio, !trigger); + + /* Now get the IRQ which tells us when the power button is hit */ + irq = irq_of_parse_and_map(halt_node, 0); + err = request_irq(irq, gpio_halt_irq, IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING, "gpio-halt", halt_node); + if (err) { + printk(KERN_ERR "gpio-halt: error requesting IRQ %d for " + "GPIO %d.\n", irq, gpio); + gpio_free(gpio); + halt_node = NULL; + return err; + } + + /* Register our halt function */ + ppc_md.halt = gpio_halt_cb; + pm_power_off = gpio_halt_cb; + + printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" + " irq).\n", gpio, trigger, irq); + + return 0; +} + +static int gpio_halt_remove(struct platform_device *pdev) +{ + if (halt_node) { + int gpio = of_get_gpio(halt_node, 0); + int irq = irq_of_parse_and_map(halt_node, 0); + + free_irq(irq, halt_node); + + ppc_md.halt = NULL; + pm_power_off = NULL; + + gpio_free(gpio); + + halt_node = NULL; + } + + return 0; +} + +static const struct of_device_id gpio_halt_match[] = { + /* We match on the gpio bus itself and scan the children since they + * wont be matched against us. We know the bus wont match until it + * has been registered too. */ + { + .compatible = "fsl,qoriq-gpio", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, gpio_halt_match); + +static struct platform_driver gpio_halt_driver = { + .driver = { + .name = "gpio-halt", + .of_match_table = gpio_halt_match, + }, + .probe = gpio_halt_probe, + .remove = gpio_halt_remove, +}; + +module_platform_driver(gpio_halt_driver); + +MODULE_DESCRIPTION("Driver to support GPIO triggered system halt for Servergy CTS-1000 Systems."); +MODULE_VERSION("1.0"); +MODULE_AUTHOR("Ben Collins <ben.c@servergy.com>"); +MODULE_LICENSE("GPL"); |