diff options
Diffstat (limited to 'arch/sparc/kernel/apc.c')
| -rw-r--r-- | arch/sparc/kernel/apc.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/arch/sparc/kernel/apc.c b/arch/sparc/kernel/apc.c new file mode 100644 index 000000000..d44725d37 --- /dev/null +++ b/arch/sparc/kernel/apc.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0 +/* apc - Driver implementation for power management functions + * of Aurora Personality Chip (APC) on SPARCstation-4/5 and + * derivatives. + * + * Copyright (c) 2002 Eric Brower (ebrower@usa.net) + */ + +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/miscdevice.h> +#include <linux/pm.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/module.h> + +#include <asm/io.h> +#include <asm/oplib.h> +#include <linux/uaccess.h> +#include <asm/auxio.h> +#include <asm/apc.h> +#include <asm/processor.h> + +/* Debugging + * + * #define APC_DEBUG_LED + */ + +#define APC_MINOR MISC_DYNAMIC_MINOR +#define APC_OBPNAME "power-management" +#define APC_DEVNAME "apc" + +static u8 __iomem *regs; +static int apc_no_idle = 0; + +#define apc_readb(offs) (sbus_readb(regs+offs)) +#define apc_writeb(val, offs) (sbus_writeb(val, regs+offs)) + +/* Specify "apc=noidle" on the kernel command line to + * disable APC CPU standby support. Certain prototype + * systems (SPARCstation-Fox) do not play well with APC + * CPU idle, so disable this if your system has APC and + * crashes randomly. + */ +static int __init apc_setup(char *str) +{ + if(!strncmp(str, "noidle", strlen("noidle"))) { + apc_no_idle = 1; + return 1; + } + return 0; +} +__setup("apc=", apc_setup); + +/* + * CPU idle callback function + * See .../arch/sparc/kernel/process.c + */ +static void apc_swift_idle(void) +{ +#ifdef APC_DEBUG_LED + set_auxio(0x00, AUXIO_LED); +#endif + + apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG); + +#ifdef APC_DEBUG_LED + set_auxio(AUXIO_LED, 0x00); +#endif +} + +static inline void apc_free(struct platform_device *op) +{ + of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0])); +} + +static int apc_open(struct inode *inode, struct file *f) +{ + return 0; +} + +static int apc_release(struct inode *inode, struct file *f) +{ + return 0; +} + +static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg) +{ + __u8 inarg, __user *arg = (__u8 __user *) __arg; + + switch (cmd) { + case APCIOCGFANCTL: + if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) + return -EFAULT; + break; + + case APCIOCGCPWR: + if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) + return -EFAULT; + break; + + case APCIOCGBPORT: + if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) + return -EFAULT; + break; + + case APCIOCSFANCTL: + if (get_user(inarg, arg)) + return -EFAULT; + apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG); + break; + + case APCIOCSCPWR: + if (get_user(inarg, arg)) + return -EFAULT; + apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG); + break; + + case APCIOCSBPORT: + if (get_user(inarg, arg)) + return -EFAULT; + apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG); + break; + + default: + return -EINVAL; + } + + return 0; +} + +static const struct file_operations apc_fops = { + .unlocked_ioctl = apc_ioctl, + .open = apc_open, + .release = apc_release, + .llseek = noop_llseek, +}; + +static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops }; + +static int apc_probe(struct platform_device *op) +{ + int err; + + regs = of_ioremap(&op->resource[0], 0, + resource_size(&op->resource[0]), APC_OBPNAME); + if (!regs) { + printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); + return -ENODEV; + } + + err = misc_register(&apc_miscdev); + if (err) { + printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); + apc_free(op); + return -ENODEV; + } + + /* Assign power management IDLE handler */ + if (!apc_no_idle) + sparc_idle = apc_swift_idle; + + printk(KERN_INFO "%s: power management initialized%s\n", + APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); + + return 0; +} + +static const struct of_device_id apc_match[] = { + { + .name = APC_OBPNAME, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, apc_match); + +static struct platform_driver apc_driver = { + .driver = { + .name = "apc", + .of_match_table = apc_match, + }, + .probe = apc_probe, +}; + +static int __init apc_init(void) +{ + return platform_driver_register(&apc_driver); +} + +/* This driver is not critical to the boot process + * and is easiest to ioremap when SBus is already + * initialized, so we install ourselves thusly: + */ +__initcall(apc_init); |