1 // SPDX-License-Identifier: GPL-2.0 2 /* pmc - Driver implementation for power management functions 3 * of Power Management Controller (PMC) on SPARCstation-Voyager. 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/pm.h> 13 #include <linux/of.h> 14 #include <linux/of_device.h> 15 #include <linux/module.h> 16 17 #include <asm/io.h> 18 #include <asm/oplib.h> 19 #include <linux/uaccess.h> 20 #include <asm/auxio.h> 21 #include <asm/processor.h> 22 23 /* Debug 24 * 25 * #define PMC_DEBUG_LED 26 * #define PMC_NO_IDLE 27 */ 28 29 #define PMC_OBPNAME "SUNW,pmc" 30 #define PMC_DEVNAME "pmc" 31 32 #define PMC_IDLE_REG 0x00 33 #define PMC_IDLE_ON 0x01 34 35 static u8 __iomem *regs; 36 37 #define pmc_readb(offs) (sbus_readb(regs+offs)) 38 #define pmc_writeb(val, offs) (sbus_writeb(val, regs+offs)) 39 40 /* 41 * CPU idle callback function 42 * See .../arch/sparc/kernel/process.c 43 */ 44 static void pmc_swift_idle(void) 45 { 46 #ifdef PMC_DEBUG_LED 47 set_auxio(0x00, AUXIO_LED); 48 #endif 49 50 pmc_writeb(pmc_readb(PMC_IDLE_REG) | PMC_IDLE_ON, PMC_IDLE_REG); 51 52 #ifdef PMC_DEBUG_LED 53 set_auxio(AUXIO_LED, 0x00); 54 #endif 55 } 56 57 static int pmc_probe(struct platform_device *op) 58 { 59 regs = of_ioremap(&op->resource[0], 0, 60 resource_size(&op->resource[0]), PMC_OBPNAME); 61 if (!regs) { 62 printk(KERN_ERR "%s: unable to map registers\n", PMC_DEVNAME); 63 return -ENODEV; 64 } 65 66 #ifndef PMC_NO_IDLE 67 /* Assign power management IDLE handler */ 68 sparc_idle = pmc_swift_idle; 69 #endif 70 71 printk(KERN_INFO "%s: power management initialized\n", PMC_DEVNAME); 72 return 0; 73 } 74 75 static const struct of_device_id pmc_match[] = { 76 { 77 .name = PMC_OBPNAME, 78 }, 79 {}, 80 }; 81 MODULE_DEVICE_TABLE(of, pmc_match); 82 83 static struct platform_driver pmc_driver = { 84 .driver = { 85 .name = "pmc", 86 .of_match_table = pmc_match, 87 }, 88 .probe = pmc_probe, 89 }; 90 91 static int __init pmc_init(void) 92 { 93 return platform_driver_register(&pmc_driver); 94 } 95 96 /* This driver is not critical to the boot process 97 * and is easiest to ioremap when SBus is already 98 * initialized, so we install ourselves thusly: 99 */ 100 __initcall(pmc_init); 101