1/* apc - Driver implementation for power management functions 2 * of Aurora Personality Chip (APC) on SPARCstation-4/5 and 3 * derivatives. 4 * 5 * Copyright (c) 2002 Eric Brower (ebrower@usa.net) 6 */ 7 8#include <linux/kernel.h> 9#include <linux/fs.h> 10#include <linux/errno.h> 11#include <linux/init.h> 12#include <linux/miscdevice.h> 13#include <linux/pm.h> 14#include <linux/of.h> 15#include <linux/of_device.h> 16 17#include <asm/io.h> 18#include <asm/oplib.h> 19#include <asm/uaccess.h> 20#include <asm/auxio.h> 21#include <asm/apc.h> 22 23/* Debugging 24 * 25 * #define APC_DEBUG_LED 26 */ 27 28#define APC_MINOR MISC_DYNAMIC_MINOR 29#define APC_OBPNAME "power-management" 30#define APC_DEVNAME "apc" 31 32static u8 __iomem *regs; 33static int apc_no_idle __devinitdata = 0; 34 35#define apc_readb(offs) (sbus_readb(regs+offs)) 36#define apc_writeb(val, offs) (sbus_writeb(val, regs+offs)) 37 38/* Specify "apc=noidle" on the kernel command line to 39 * disable APC CPU standby support. Certain prototype 40 * systems (SPARCstation-Fox) do not play well with APC 41 * CPU idle, so disable this if your system has APC and 42 * crashes randomly. 43 */ 44static int __init apc_setup(char *str) 45{ 46 if(!strncmp(str, "noidle", strlen("noidle"))) { 47 apc_no_idle = 1; 48 return 1; 49 } 50 return 0; 51} 52__setup("apc=", apc_setup); 53 54/* 55 * CPU idle callback function 56 * See .../arch/sparc/kernel/process.c 57 */ 58static void apc_swift_idle(void) 59{ 60#ifdef APC_DEBUG_LED 61 set_auxio(0x00, AUXIO_LED); 62#endif 63 64 apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG); 65 66#ifdef APC_DEBUG_LED 67 set_auxio(AUXIO_LED, 0x00); 68#endif 69} 70 71static inline void apc_free(struct platform_device *op) 72{ 73 of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0])); 74} 75 76static int apc_open(struct inode *inode, struct file *f) 77{ 78 return 0; 79} 80 81static int apc_release(struct inode *inode, struct file *f) 82{ 83 return 0; 84} 85 86static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg) 87{ 88 __u8 inarg, __user *arg = (__u8 __user *) __arg; 89 90 switch (cmd) { 91 case APCIOCGFANCTL: 92 if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) 93 return -EFAULT; 94 break; 95 96 case APCIOCGCPWR: 97 if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) 98 return -EFAULT; 99 break; 100 101 case APCIOCGBPORT: 102 if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) 103 return -EFAULT; 104 break; 105 106 case APCIOCSFANCTL: 107 if (get_user(inarg, arg)) 108 return -EFAULT; 109 apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG); 110 break; 111 112 case APCIOCSCPWR: 113 if (get_user(inarg, arg)) 114 return -EFAULT; 115 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG); 116 break; 117 118 case APCIOCSBPORT: 119 if (get_user(inarg, arg)) 120 return -EFAULT; 121 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG); 122 break; 123 124 default: 125 return -EINVAL; 126 }; 127 128 return 0; 129} 130 131static const struct file_operations apc_fops = { 132 .unlocked_ioctl = apc_ioctl, 133 .open = apc_open, 134 .release = apc_release, 135}; 136 137static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops }; 138 139static int __devinit apc_probe(struct platform_device *op, 140 const struct of_device_id *match) 141{ 142 int err; 143 144 regs = of_ioremap(&op->resource[0], 0, 145 resource_size(&op->resource[0]), APC_OBPNAME); 146 if (!regs) { 147 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); 148 return -ENODEV; 149 } 150 151 err = misc_register(&apc_miscdev); 152 if (err) { 153 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); 154 apc_free(op); 155 return -ENODEV; 156 } 157 158 /* Assign power management IDLE handler */ 159 if (!apc_no_idle) 160 pm_idle = apc_swift_idle; 161 162 printk(KERN_INFO "%s: power management initialized%s\n", 163 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); 164 165 return 0; 166} 167 168static struct of_device_id __initdata apc_match[] = { 169 { 170 .name = APC_OBPNAME, 171 }, 172 {}, 173}; 174MODULE_DEVICE_TABLE(of, apc_match); 175 176static struct of_platform_driver apc_driver = { 177 .driver = { 178 .name = "apc", 179 .owner = THIS_MODULE, 180 .of_match_table = apc_match, 181 }, 182 .probe = apc_probe, 183}; 184 185static int __init apc_init(void) 186{ 187 return of_register_platform_driver(&apc_driver); 188} 189 190/* This driver is not critical to the boot process 191 * and is easiest to ioremap when SBus is already 192 * initialized, so we install ourselves thusly: 193 */ 194__initcall(apc_init); 195