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/smp_lock.h> 14 #include <linux/pm.h> 15 16 #include <asm/io.h> 17 #include <asm/sbus.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 32 volatile static u8 __iomem *regs; 33 static int apc_regsize; 34 static int apc_no_idle __initdata = 0; 35 36 #define apc_readb(offs) (sbus_readb(regs+offs)) 37 #define apc_writeb(val, offs) (sbus_writeb(val, regs+offs)) 38 39 /* Specify "apc=noidle" on the kernel command line to 40 * disable APC CPU standby support. Certain prototype 41 * systems (SPARCstation-Fox) do not play well with APC 42 * CPU idle, so disable this if your system has APC and 43 * crashes randomly. 44 */ 45 static int __init apc_setup(char *str) 46 { 47 if(!strncmp(str, "noidle", strlen("noidle"))) { 48 apc_no_idle = 1; 49 return 1; 50 } 51 return 0; 52 } 53 __setup("apc=", apc_setup); 54 55 /* 56 * CPU idle callback function 57 * See .../arch/sparc/kernel/process.c 58 */ 59 static void apc_swift_idle(void) 60 { 61 #ifdef APC_DEBUG_LED 62 set_auxio(0x00, AUXIO_LED); 63 #endif 64 65 apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG); 66 67 #ifdef APC_DEBUG_LED 68 set_auxio(AUXIO_LED, 0x00); 69 #endif 70 } 71 72 static inline void apc_free(void) 73 { 74 sbus_iounmap(regs, apc_regsize); 75 } 76 77 static int apc_open(struct inode *inode, struct file *f) 78 { 79 cycle_kernel_lock(); 80 return 0; 81 } 82 83 static int apc_release(struct inode *inode, struct file *f) 84 { 85 return 0; 86 } 87 88 static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg) 89 { 90 __u8 inarg, __user *arg; 91 92 arg = (__u8 __user *) __arg; 93 94 lock_kernel(); 95 96 switch (cmd) { 97 case APCIOCGFANCTL: 98 if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) { 99 unlock_kernel(); 100 return -EFAULT; 101 } 102 break; 103 104 case APCIOCGCPWR: 105 if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) { 106 unlock_kernel(); 107 return -EFAULT; 108 } 109 break; 110 111 case APCIOCGBPORT: 112 if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) { 113 unlock_kernel(); 114 return -EFAULT; 115 } 116 break; 117 118 case APCIOCSFANCTL: 119 if (get_user(inarg, arg)) { 120 unlock_kernel(); 121 return -EFAULT; 122 } 123 apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG); 124 break; 125 case APCIOCSCPWR: 126 if (get_user(inarg, arg)) { 127 unlock_kernel(); 128 return -EFAULT; 129 } 130 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG); 131 break; 132 case APCIOCSBPORT: 133 if (get_user(inarg, arg)) { 134 unlock_kernel(); 135 return -EFAULT; 136 } 137 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG); 138 break; 139 default: 140 unlock_kernel(); 141 return -EINVAL; 142 }; 143 144 unlock_kernel(); 145 return 0; 146 } 147 148 static const struct file_operations apc_fops = { 149 .unlocked_ioctl = apc_ioctl, 150 .open = apc_open, 151 .release = apc_release, 152 }; 153 154 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops }; 155 156 static int __init apc_probe(void) 157 { 158 struct sbus_bus *sbus = NULL; 159 struct sbus_dev *sdev = NULL; 160 int iTmp = 0; 161 162 for_each_sbus(sbus) { 163 for_each_sbusdev(sdev, sbus) { 164 if (!strcmp(sdev->prom_name, APC_OBPNAME)) { 165 goto sbus_done; 166 } 167 } 168 } 169 170 sbus_done: 171 if (!sdev) { 172 return -ENODEV; 173 } 174 175 apc_regsize = sdev->reg_addrs[0].reg_size; 176 regs = sbus_ioremap(&sdev->resource[0], 0, 177 apc_regsize, APC_OBPNAME); 178 if(!regs) { 179 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); 180 return -ENODEV; 181 } 182 183 iTmp = misc_register(&apc_miscdev); 184 if (iTmp != 0) { 185 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); 186 apc_free(); 187 return -ENODEV; 188 } 189 190 /* Assign power management IDLE handler */ 191 if(!apc_no_idle) 192 pm_idle = apc_swift_idle; 193 194 printk(KERN_INFO "%s: power management initialized%s\n", 195 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); 196 return 0; 197 } 198 199 /* This driver is not critical to the boot process 200 * and is easiest to ioremap when SBus is already 201 * initialized, so we install ourselves thusly: 202 */ 203 __initcall(apc_probe); 204 205