1 // SPDX-License-Identifier: GPL-2.0 2 /* power.c: Power management driver. 3 * 4 * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net) 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/export.h> 9 #include <linux/init.h> 10 #include <linux/interrupt.h> 11 #include <linux/reboot.h> 12 #include <linux/of_device.h> 13 14 #include <asm/prom.h> 15 #include <asm/io.h> 16 17 static void __iomem *power_reg; 18 19 static irqreturn_t power_handler(int irq, void *dev_id) 20 { 21 orderly_poweroff(true); 22 23 /* FIXME: Check registers for status... */ 24 return IRQ_HANDLED; 25 } 26 27 static int has_button_interrupt(unsigned int irq, struct device_node *dp) 28 { 29 if (irq == 0xffffffff) 30 return 0; 31 if (!of_property_read_bool(dp, "button")) 32 return 0; 33 34 return 1; 35 } 36 37 static int power_probe(struct platform_device *op) 38 { 39 struct resource *res = &op->resource[0]; 40 unsigned int irq = op->archdata.irqs[0]; 41 42 power_reg = of_ioremap(res, 0, 0x4, "power"); 43 44 printk(KERN_INFO "%pOFn: Control reg at %llx\n", 45 op->dev.of_node, res->start); 46 47 if (has_button_interrupt(irq, op->dev.of_node)) { 48 if (request_irq(irq, 49 power_handler, 0, "power", NULL) < 0) 50 printk(KERN_ERR "power: Cannot setup IRQ handler.\n"); 51 } 52 53 return 0; 54 } 55 56 static const struct of_device_id power_match[] = { 57 { 58 .name = "power", 59 }, 60 {}, 61 }; 62 63 static struct platform_driver power_driver = { 64 .probe = power_probe, 65 .driver = { 66 .name = "power", 67 .of_match_table = power_match, 68 }, 69 }; 70 71 builtin_platform_driver(power_driver); 72