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 #include <linux/module.h> 17 18 #include <asm/io.h> 19 #include <asm/oplib.h> 20 #include <asm/uaccess.h> 21 #include <asm/auxio.h> 22 #include <asm/apc.h> 23 24 /* Debugging 25 * 26 * #define APC_DEBUG_LED 27 */ 28 29 #define APC_MINOR MISC_DYNAMIC_MINOR 30 #define APC_OBPNAME "power-management" 31 #define APC_DEVNAME "apc" 32 33 static u8 __iomem *regs; 34 static int apc_no_idle __devinitdata = 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(struct platform_device *op) 73 { 74 of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0])); 75 } 76 77 static int apc_open(struct inode *inode, struct file *f) 78 { 79 return 0; 80 } 81 82 static int apc_release(struct inode *inode, struct file *f) 83 { 84 return 0; 85 } 86 87 static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg) 88 { 89 __u8 inarg, __user *arg = (__u8 __user *) __arg; 90 91 switch (cmd) { 92 case APCIOCGFANCTL: 93 if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) 94 return -EFAULT; 95 break; 96 97 case APCIOCGCPWR: 98 if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) 99 return -EFAULT; 100 break; 101 102 case APCIOCGBPORT: 103 if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) 104 return -EFAULT; 105 break; 106 107 case APCIOCSFANCTL: 108 if (get_user(inarg, arg)) 109 return -EFAULT; 110 apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG); 111 break; 112 113 case APCIOCSCPWR: 114 if (get_user(inarg, arg)) 115 return -EFAULT; 116 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG); 117 break; 118 119 case APCIOCSBPORT: 120 if (get_user(inarg, arg)) 121 return -EFAULT; 122 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG); 123 break; 124 125 default: 126 return -EINVAL; 127 } 128 129 return 0; 130 } 131 132 static const struct file_operations apc_fops = { 133 .unlocked_ioctl = apc_ioctl, 134 .open = apc_open, 135 .release = apc_release, 136 .llseek = noop_llseek, 137 }; 138 139 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops }; 140 141 static int __devinit apc_probe(struct platform_device *op) 142 { 143 int err; 144 145 regs = of_ioremap(&op->resource[0], 0, 146 resource_size(&op->resource[0]), APC_OBPNAME); 147 if (!regs) { 148 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); 149 return -ENODEV; 150 } 151 152 err = misc_register(&apc_miscdev); 153 if (err) { 154 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); 155 apc_free(op); 156 return -ENODEV; 157 } 158 159 /* Assign power management IDLE handler */ 160 if (!apc_no_idle) 161 pm_idle = apc_swift_idle; 162 163 printk(KERN_INFO "%s: power management initialized%s\n", 164 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); 165 166 return 0; 167 } 168 169 static struct of_device_id apc_match[] = { 170 { 171 .name = APC_OBPNAME, 172 }, 173 {}, 174 }; 175 MODULE_DEVICE_TABLE(of, apc_match); 176 177 static struct platform_driver apc_driver = { 178 .driver = { 179 .name = "apc", 180 .owner = THIS_MODULE, 181 .of_match_table = apc_match, 182 }, 183 .probe = apc_probe, 184 }; 185 186 static int __init apc_init(void) 187 { 188 return platform_driver_register(&apc_driver); 189 } 190 191 /* This driver is not critical to the boot process 192 * and is easiest to ioremap when SBus is already 193 * initialized, so we install ourselves thusly: 194 */ 195 __initcall(apc_init); 196