1 /* 2 * Power off driver for ams AS3722 device. 3 * 4 * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved. 5 * 6 * Author: Laxman Dewangan <ldewangan@nvidia.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms and conditions of the GNU General Public License, 10 * version 2, as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 */ 17 18 #include <linux/mfd/as3722.h> 19 #include <linux/module.h> 20 #include <linux/of.h> 21 #include <linux/of_device.h> 22 #include <linux/platform_device.h> 23 #include <linux/slab.h> 24 25 struct as3722_poweroff { 26 struct device *dev; 27 struct as3722 *as3722; 28 }; 29 30 static struct as3722_poweroff *as3722_pm_poweroff; 31 32 static void as3722_pm_power_off(void) 33 { 34 int ret; 35 36 if (!as3722_pm_poweroff) { 37 pr_err("AS3722 poweroff is not initialised\n"); 38 return; 39 } 40 41 ret = as3722_update_bits(as3722_pm_poweroff->as3722, 42 AS3722_RESET_CONTROL_REG, AS3722_POWER_OFF, AS3722_POWER_OFF); 43 if (ret < 0) 44 dev_err(as3722_pm_poweroff->dev, 45 "RESET_CONTROL_REG update failed, %d\n", ret); 46 } 47 48 static int as3722_poweroff_probe(struct platform_device *pdev) 49 { 50 struct as3722_poweroff *as3722_poweroff; 51 struct device_node *np = pdev->dev.parent->of_node; 52 53 if (!np) 54 return -EINVAL; 55 56 if (!of_property_read_bool(np, "ams,system-power-controller")) 57 return 0; 58 59 as3722_poweroff = devm_kzalloc(&pdev->dev, sizeof(*as3722_poweroff), 60 GFP_KERNEL); 61 if (!as3722_poweroff) 62 return -ENOMEM; 63 64 as3722_poweroff->as3722 = dev_get_drvdata(pdev->dev.parent); 65 as3722_poweroff->dev = &pdev->dev; 66 as3722_pm_poweroff = as3722_poweroff; 67 if (!pm_power_off) 68 pm_power_off = as3722_pm_power_off; 69 70 return 0; 71 } 72 73 static int as3722_poweroff_remove(struct platform_device *pdev) 74 { 75 if (pm_power_off == as3722_pm_power_off) 76 pm_power_off = NULL; 77 as3722_pm_poweroff = NULL; 78 79 return 0; 80 } 81 82 static struct platform_driver as3722_poweroff_driver = { 83 .driver = { 84 .name = "as3722-power-off", 85 .owner = THIS_MODULE, 86 }, 87 .probe = as3722_poweroff_probe, 88 .remove = as3722_poweroff_remove, 89 }; 90 91 module_platform_driver(as3722_poweroff_driver); 92 93 MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device"); 94 MODULE_ALIAS("platform:as3722-power-off"); 95 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); 96 MODULE_LICENSE("GPL v2"); 97