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 <linux/uaccess.h> 21 #include <asm/auxio.h> 22 #include <asm/apc.h> 23 #include <asm/processor.h> 24 25 /* Debugging 26 * 27 * #define APC_DEBUG_LED 28 */ 29 30 #define APC_MINOR MISC_DYNAMIC_MINOR 31 #define APC_OBPNAME "power-management" 32 #define APC_DEVNAME "apc" 33 34 static u8 __iomem *regs; 35 static int apc_no_idle = 0; 36 37 #define apc_readb(offs) (sbus_readb(regs+offs)) 38 #define apc_writeb(val, offs) (sbus_writeb(val, regs+offs)) 39 40 /* Specify "apc=noidle" on the kernel command line to 41 * disable APC CPU standby support. Certain prototype 42 * systems (SPARCstation-Fox) do not play well with APC 43 * CPU idle, so disable this if your system has APC and 44 * crashes randomly. 45 */ 46 static int __init apc_setup(char *str) 47 { 48 if(!strncmp(str, "noidle", strlen("noidle"))) { 49 apc_no_idle = 1; 50 return 1; 51 } 52 return 0; 53 } 54 __setup("apc=", apc_setup); 55 56 /* 57 * CPU idle callback function 58 * See .../arch/sparc/kernel/process.c 59 */ 60 static void apc_swift_idle(void) 61 { 62 #ifdef APC_DEBUG_LED 63 set_auxio(0x00, AUXIO_LED); 64 #endif 65 66 apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG); 67 68 #ifdef APC_DEBUG_LED 69 set_auxio(AUXIO_LED, 0x00); 70 #endif 71 } 72 73 static inline void apc_free(struct platform_device *op) 74 { 75 of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0])); 76 } 77 78 static int apc_open(struct inode *inode, struct file *f) 79 { 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 = (__u8 __user *) __arg; 91 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; 113 114 case APCIOCSCPWR: 115 if (get_user(inarg, arg)) 116 return -EFAULT; 117 apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG); 118 break; 119 120 case APCIOCSBPORT: 121 if (get_user(inarg, arg)) 122 return -EFAULT; 123 apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG); 124 break; 125 126 default: 127 return -EINVAL; 128 } 129 130 return 0; 131 } 132 133 static const struct file_operations apc_fops = { 134 .unlocked_ioctl = apc_ioctl, 135 .open = apc_open, 136 .release = apc_release, 137 .llseek = noop_llseek, 138 }; 139 140 static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops }; 141 142 static int apc_probe(struct platform_device *op) 143 { 144 int err; 145 146 regs = of_ioremap(&op->resource[0], 0, 147 resource_size(&op->resource[0]), APC_OBPNAME); 148 if (!regs) { 149 printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME); 150 return -ENODEV; 151 } 152 153 err = misc_register(&apc_miscdev); 154 if (err) { 155 printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME); 156 apc_free(op); 157 return -ENODEV; 158 } 159 160 /* Assign power management IDLE handler */ 161 if (!apc_no_idle) 162 sparc_idle = apc_swift_idle; 163 164 printk(KERN_INFO "%s: power management initialized%s\n", 165 APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : ""); 166 167 return 0; 168 } 169 170 static struct of_device_id apc_match[] = { 171 { 172 .name = APC_OBPNAME, 173 }, 174 {}, 175 }; 176 MODULE_DEVICE_TABLE(of, apc_match); 177 178 static struct platform_driver apc_driver = { 179 .driver = { 180 .name = "apc", 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