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.h> 13 #include <linux/platform_device.h> 14 15 #include <asm/prom.h> 16 #include <asm/io.h> 17 18 static void __iomem *power_reg; 19 20 static irqreturn_t power_handler(int irq, void *dev_id) 21 { 22 orderly_poweroff(true); 23 24 /* FIXME: Check registers for status... */ 25 return IRQ_HANDLED; 26 } 27 28 static int has_button_interrupt(unsigned int irq, struct device_node *dp) 29 { 30 if (irq == 0xffffffff) 31 return 0; 32 if (!of_property_read_bool(dp, "button")) 33 return 0; 34 35 return 1; 36 } 37 38 static int power_probe(struct platform_device *op) 39 { 40 struct resource *res = &op->resource[0]; 41 unsigned int irq = op->archdata.irqs[0]; 42 43 power_reg = of_ioremap(res, 0, 0x4, "power"); 44 45 printk(KERN_INFO "%pOFn: Control reg at %llx\n", 46 op->dev.of_node, res->start); 47 48 if (has_button_interrupt(irq, op->dev.of_node)) { 49 if (request_irq(irq, 50 power_handler, 0, "power", NULL) < 0) 51 printk(KERN_ERR "power: Cannot setup IRQ handler.\n"); 52 } 53 54 return 0; 55 } 56 57 static const struct of_device_id power_match[] = { 58 { 59 .name = "power", 60 }, 61 {}, 62 }; 63 64 static struct platform_driver power_driver = { 65 .probe = power_probe, 66 .driver = { 67 .name = "power", 68 .of_match_table = power_match, 69 }, 70 }; 71 72 builtin_platform_driver(power_driver); 73