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/platform_device.h> 14 #include <linux/reset-controller.h> 15 16 #define to_axs10x_rst(p) container_of((p), struct axs10x_rst, rcdev) 17 18 #define AXS10X_MAX_RESETS 32 19 20 struct axs10x_rst { 21 void __iomem *regs_rst; 22 spinlock_t lock; 23 struct reset_controller_dev rcdev; 24 }; 25 26 static int axs10x_reset_reset(struct reset_controller_dev *rcdev, 27 unsigned long id) 28 { 29 struct axs10x_rst *rst = to_axs10x_rst(rcdev); 30 unsigned long flags; 31 32 spin_lock_irqsave(&rst->lock, flags); 33 writel(BIT(id), rst->regs_rst); 34 spin_unlock_irqrestore(&rst->lock, flags); 35 36 return 0; 37 } 38 39 static const struct reset_control_ops axs10x_reset_ops = { 40 .reset = axs10x_reset_reset, 41 }; 42 43 static int axs10x_reset_probe(struct platform_device *pdev) 44 { 45 struct axs10x_rst *rst; 46 struct resource *mem; 47 48 rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL); 49 if (!rst) 50 return -ENOMEM; 51 52 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 53 rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem); 54 if (IS_ERR(rst->regs_rst)) 55 return PTR_ERR(rst->regs_rst); 56 57 spin_lock_init(&rst->lock); 58 59 rst->rcdev.owner = THIS_MODULE; 60 rst->rcdev.ops = &axs10x_reset_ops; 61 rst->rcdev.of_node = pdev->dev.of_node; 62 rst->rcdev.nr_resets = AXS10X_MAX_RESETS; 63 64 return devm_reset_controller_register(&pdev->dev, &rst->rcdev); 65 } 66 67 static const struct of_device_id axs10x_reset_dt_match[] = { 68 { .compatible = "snps,axs10x-reset" }, 69 { }, 70 }; 71 72 static struct platform_driver axs10x_reset_driver = { 73 .probe = axs10x_reset_probe, 74 .driver = { 75 .name = "axs10x-reset", 76 .of_match_table = axs10x_reset_dt_match, 77 }, 78 }; 79 builtin_platform_driver(axs10x_reset_driver); 80 81 MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>"); 82 MODULE_DESCRIPTION("Synopsys AXS10x reset driver"); 83 MODULE_LICENSE("GPL v2"); 84