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 #include <linux/of.h> 16 #include <linux/of_device.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 of_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 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 __devinit apc_probe(struct of_device *op, 157 const struct of_device_id *match) 158 { 159 int err; 160 161 regs = of_ioremap(&op->resource[0], 0, 162 resource_size(&op->resource[0]), APC_OBPNAME); 163 if (!regs) { 164 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); 165 return -ENODEV; 166 } 167 168 err = misc_register(&apc_miscdev); 169 if (err) { 170 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); 171 apc_free(op); 172 return -ENODEV; 173 } 174 175 /* Assign power management IDLE handler */ 176 if (!apc_no_idle) 177 pm_idle = apc_swift_idle; 178 179 printk(KERN_INFO "%s: power management initialized%s\n", 180 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); 181 182 return 0; 183 } 184 185 static struct of_device_id __initdata apc_match[] = { 186 { 187 .name = APC_OBPNAME, 188 }, 189 {}, 190 }; 191 MODULE_DEVICE_TABLE(of, apc_match); 192 193 static struct of_platform_driver apc_driver = { 194 .name = "apc", 195 .match_table = apc_match, 196 .probe = apc_probe, 197 }; 198 199 static int __init apc_init(void) 200 { 201 return of_register_driver(&apc_driver, &of_bus_type); 202 } 203 204 /* This driver is not critical to the boot process 205 * and is easiest to ioremap when SBus is already 206 * initialized, so we install ourselves thusly: 207 */ 208 __initcall(apc_init); 209