1 /* 2 * Copyright (C) 2017 Synopsys. 3 * 4 * Synopsys AXS10x reset driver. 5 * 6 * This file is licensed under the terms of the GNU General Public 7 * License version 2. This program is licensed "as is" without any 8 * warranty of any kind, whether express or implied. 9 */ 10 11 #include <linux/io.h> 12 #include <linux/module.h> 13 #include <linux/mod_devicetable.h> 14 #include <linux/platform_device.h> 15 #include <linux/reset-controller.h> 16 17 #define to_axs10x_rst(p) container_of((p), struct axs10x_rst, rcdev) 18 19 #define AXS10X_MAX_RESETS 32 20 21 struct axs10x_rst { 22 void __iomem *regs_rst; 23 spinlock_t lock; 24 struct reset_controller_dev rcdev; 25 }; 26 27 static int axs10x_reset_reset(struct reset_controller_dev *rcdev, 28 unsigned long id) 29 { 30 struct axs10x_rst *rst = to_axs10x_rst(rcdev); 31 unsigned long flags; 32 33 spin_lock_irqsave(&rst->lock, flags); 34 writel(BIT(id), rst->regs_rst); 35 spin_unlock_irqrestore(&rst->lock, flags); 36 37 return 0; 38 } 39 40 static const struct reset_control_ops axs10x_reset_ops = { 41 .reset = axs10x_reset_reset, 42 }; 43 44 static int axs10x_reset_probe(struct platform_device *pdev) 45 { 46 struct axs10x_rst *rst; 47 struct resource *mem; 48 49 rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL); 50 if (!rst) 51 return -ENOMEM; 52 53 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 54 rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem); 55 if (IS_ERR(rst->regs_rst)) 56 return PTR_ERR(rst->regs_rst); 57 58 spin_lock_init(&rst->lock); 59 60 rst->rcdev.owner = THIS_MODULE; 61 rst->rcdev.ops = &axs10x_reset_ops; 62 rst->rcdev.of_node = pdev->dev.of_node; 63 rst->rcdev.nr_resets = AXS10X_MAX_RESETS; 64 65 return devm_reset_controller_register(&pdev->dev, &rst->rcdev); 66 } 67 68 static const struct of_device_id axs10x_reset_dt_match[] = { 69 { .compatible = "snps,axs10x-reset" }, 70 { }, 71 }; 72 73 static struct platform_driver axs10x_reset_driver = { 74 .probe = axs10x_reset_probe, 75 .driver = { 76 .name = "axs10x-reset", 77 .of_match_table = axs10x_reset_dt_match, 78 }, 79 }; 80 builtin_platform_driver(axs10x_reset_driver); 81 82 MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>"); 83 MODULE_DESCRIPTION("Synopsys AXS10x reset driver"); 84 MODULE_LICENSE("GPL v2"); 85