diff options
author | Benjamin Collins <ben.c@servergy.com> | 2012-12-17 04:19:28 +0000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-01-29 11:35:05 +1100 |
commit | 5611fe48c545a22e62273428ed74c9bfae4a9406 (patch) | |
tree | 79514228d518fe3adb823290879190157d299c1c | |
parent | 34f364fef475f5d960b74bf074d65392ece50235 (diff) | |
download | linux-5611fe48c545a22e62273428ed74c9bfae4a9406.tar.bz2 |
powerpc: Add support for CTS-1000 GPIO controlled system poweroff
CTS-1000 is based on P4080. GPIO 27 is used to signal the FPGA to
switch off power, and also associates IRQ 8 with front-panel button
press (which we use to call orderly_poweroff()).
The relevant device-tree looks like this:
gpio0: gpio@130000 {
compatible = "fsl,qoriq-gpio";
reg = <0x130000 0x1000>;
interrupts = <55 2 0 0>;
#gpio-cells = <2>;
gpio-controller;
/* Allows powering off the system via GPIO signal. */
gpio-halt@27 {
compatible = "sgy,gpio-halt";
gpios = <&gpio0 27 0>;
interrupts = <8 1 0 0>;
};
};
Because the driver cannot match on sgy,gpio-halt (because the node is never
processed through of_platform), it matches on fsl,qoriq-gpio and then
checks child nodes for the matching sgy,gpio-halt. This also ensures that
the GPIO controller is detected prior to sgy_cts1000's probe callback,
since that node wont match via of_platform until the controller is
registered.
Also, because the GPIO handler for triggering system poweroff might sleep,
the IRQ uses a workqueue to call orderly_poweroff().
As a final note, this driver may be expanded for other features specific to
the CTS-1000.
Signed-off-by: Ben Collins <ben.c@servergy.com>
Cc: Jack Smith <jack.s@servergy.com>
Cc: Vihar Rai <vihar.r@servergy.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r-- | arch/powerpc/platforms/85xx/Kconfig | 8 | ||||
-rw-r--r-- | arch/powerpc/platforms/85xx/Makefile | 1 | ||||
-rw-r--r-- | arch/powerpc/platforms/85xx/sgy_cts1000.c | 176 |
3 files changed, 185 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/85xx/Kconfig b/arch/powerpc/platforms/85xx/Kconfig index 02d02a09942d..651788cbc6e6 100644 --- a/arch/powerpc/platforms/85xx/Kconfig +++ b/arch/powerpc/platforms/85xx/Kconfig @@ -245,6 +245,14 @@ config P4080_DS help This option enables support for the P4080 DS board +config SGY_CTS1000 + tristate "Servergy CTS-1000 support" + select GPIOLIB + select OF_GPIO + depends on P4080_DS + help + Enable this to support functionality in Servergy's CTS-1000 systems. + endif # PPC32 config P5020_DS diff --git a/arch/powerpc/platforms/85xx/Makefile b/arch/powerpc/platforms/85xx/Makefile index 76f679cb04a0..9db31dcbd320 100644 --- a/arch/powerpc/platforms/85xx/Makefile +++ b/arch/powerpc/platforms/85xx/Makefile @@ -30,3 +30,4 @@ obj-$(CONFIG_KSI8560) += ksi8560.o obj-$(CONFIG_XES_MPC85xx) += xes_mpc85xx.o obj-$(CONFIG_GE_IMP3A) += ge_imp3a.o obj-$(CONFIG_PPC_QEMU_E500) += qemu_e500.o +obj-$(CONFIG_SGY_CTS1000) += sgy_cts1000.o diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c new file mode 100644 index 000000000000..611e92f291c4 --- /dev/null +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c @@ -0,0 +1,176 @@ +/* + * 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/init.h> +#include <linux/of_gpio.h> +#include <linux/workqueue.h> +#include <linux/reboot.h> +#include <linux/interrupt.h> + +#include <asm/machdep.h> + +static struct device_node *halt_node; + +static 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 gpio_halt_cb(void) +{ + enum of_gpio_flags flags; + int trigger, gpio; + + if (!halt_node) + return; + + gpio = of_get_gpio_flags(halt_node, 0, &flags); + + if (!gpio_is_valid(gpio)) + return; + + trigger = (flags == OF_GPIO_ACTIVE_LOW); + + printk(KERN_INFO "gpio-halt: triggering GPIO.\n"); + + /* Probably wont return */ + gpio_set_value(gpio, trigger); +} + +/* 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 __devinit 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; + ppc_md.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 __devexit 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; + ppc_md.power_off = NULL; + + gpio_free(gpio); + + halt_node = NULL; + } + + return 0; +} + +static 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", + .owner = THIS_MODULE, + .of_match_table = gpio_halt_match, + }, + .probe = gpio_halt_probe, + .remove = __devexit_p(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"); |