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 15 #include <asm/io.h> 16 #include <asm/sbus.h> 17 #include <asm/oplib.h> 18 #include <asm/uaccess.h> 19 #include <asm/auxio.h> 20 #include <asm/apc.h> 21 22 /* Debugging 23 * 24 * #define APC_DEBUG_LED 25 */ 26 27 #define APC_MINOR MISC_DYNAMIC_MINOR 28 #define APC_OBPNAME "power-management" 29 #define APC_DEVNAME "apc" 30 31 volatile static u8 __iomem *regs; 32 static int apc_regsize; 33 static int apc_no_idle __initdata = 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 */ 44 static 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 */ 58 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 71 static inline void apc_free(void) 72 { 73 sbus_iounmap(regs, apc_regsize); 74 } 75 76 static int apc_open(struct inode *inode, struct file *f) 77 { 78 return 0; 79 } 80 81 static int apc_release(struct inode *inode, struct file *f) 82 { 83 return 0; 84 } 85 86 static int apc_ioctl(struct inode *inode, struct file *f, 87 unsigned int cmd, unsigned long __arg) 88 { 89 __u8 inarg, __user *arg; 90 91 arg = (__u8 __user *) __arg; 92 switch (cmd) { 93 case APCIOCGFANCTL: 94 if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) 95 return -EFAULT; 96 break; 97 98 case APCIOCGCPWR: 99 if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) 100 return -EFAULT; 101 break; 102 103 case APCIOCGBPORT: 104 if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) 105 return -EFAULT; 106 break; 107 108 case APCIOCSFANCTL: 109 if (get_user(inarg, arg)) 110 return -EFAULT; 111 apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG); 112 break; 113 case APCIOCSCPWR: 114 if (get_user(inarg, arg)) 115 return -EFAULT; 116 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG); 117 break; 118 case APCIOCSBPORT: 119 if (get_user(inarg, arg)) 120 return -EFAULT; 121 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG); 122 break; 123 default: 124 return -EINVAL; 125 }; 126 127 return 0; 128 } 129 130 static struct file_operations apc_fops = { 131 .ioctl = apc_ioctl, 132 .open = apc_open, 133 .release = apc_release, 134 }; 135 136 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops }; 137 138 static int __init apc_probe(void) 139 { 140 struct sbus_bus *sbus = NULL; 141 struct sbus_dev *sdev = NULL; 142 int iTmp = 0; 143 144 for_each_sbus(sbus) { 145 for_each_sbusdev(sdev, sbus) { 146 if (!strcmp(sdev->prom_name, APC_OBPNAME)) { 147 goto sbus_done; 148 } 149 } 150 } 151 152 sbus_done: 153 if (!sdev) { 154 return -ENODEV; 155 } 156 157 apc_regsize = sdev->reg_addrs[0].reg_size; 158 regs = sbus_ioremap(&sdev->resource[0], 0, 159 apc_regsize, APC_OBPNAME); 160 if(!regs) { 161 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); 162 return -ENODEV; 163 } 164 165 iTmp = misc_register(&apc_miscdev); 166 if (iTmp != 0) { 167 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); 168 apc_free(); 169 return -ENODEV; 170 } 171 172 /* Assign power management IDLE handler */ 173 if(!apc_no_idle) 174 pm_idle = apc_swift_idle; 175 176 printk(KERN_INFO "%s: power management initialized%s\n", 177 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); 178 return 0; 179 } 180 181 /* This driver is not critical to the boot process 182 * and is easiest to ioremap when SBus is already 183 * initialized, so we install ourselves thusly: 184 */ 185 __initcall(apc_probe); 186 187