drivers/reset/reset-axs10x.c

0001 /*
0002  * Copyright (C) 2017 Synopsys.
0003  *
0004  * Synopsys AXS10x reset driver.
0005  *
0006  * This file is licensed under the terms of the GNU General Public
0007  * License version 2. This program is licensed "as is" without any
0008  * warranty of any kind, whether express or implied.
0009  */
0010
0011 #include <linux/io.h>
0012 #include <linux/module.h>
0013 #include <linux/mod_devicetable.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/reset-controller.h>
0016
0017 #define to_axs10x_rst(p)    container_of((p), struct axs10x_rst, rcdev)
0018
0019 #define AXS10X_MAX_RESETS   32
0020
0021 struct axs10x_rst {
0022     void __iomem            *regs_rst;
0023     spinlock_t          lock;
0024     struct reset_controller_dev rcdev;
0025 };
0026
0027 static int axs10x_reset_reset(struct reset_controller_dev *rcdev,
0028                   unsigned long id)
0029 {
0030     struct axs10x_rst *rst = to_axs10x_rst(rcdev);
0031     unsigned long flags;
0032
0033     spin_lock_irqsave(&rst->lock, flags);
0034     writel(BIT(id), rst->regs_rst);
0035     spin_unlock_irqrestore(&rst->lock, flags);
0036
0037     return 0;
0038 }
0039
0040 static const struct reset_control_ops axs10x_reset_ops = {
0041     .reset  = axs10x_reset_reset,
0042 };
0043
0044 static int axs10x_reset_probe(struct platform_device *pdev)
0045 {
0046     struct axs10x_rst *rst;
0047     struct resource *mem;
0048
0049     rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL);
0050     if (!rst)
0051         return -ENOMEM;
0052
0053     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0054     rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem);
0055     if (IS_ERR(rst->regs_rst))
0056         return PTR_ERR(rst->regs_rst);
0057
0058     spin_lock_init(&rst->lock);
0059
0060     rst->rcdev.owner = THIS_MODULE;
0061     rst->rcdev.ops = &axs10x_reset_ops;
0062     rst->rcdev.of_node = pdev->dev.of_node;
0063     rst->rcdev.nr_resets = AXS10X_MAX_RESETS;
0064
0065     return devm_reset_controller_register(&pdev->dev, &rst->rcdev);
0066 }
0067
0068 static const struct of_device_id axs10x_reset_dt_match[] = {
0069     { .compatible = "snps,axs10x-reset" },
0070     { },
0071 };
0072
0073 static struct platform_driver axs10x_reset_driver = {
0074     .probe  = axs10x_reset_probe,
0075     .driver = {
0076         .name = "axs10x-reset",
0077         .of_match_table = axs10x_reset_dt_match,
0078     },
0079 };
0080 builtin_platform_driver(axs10x_reset_driver);
0081
0082 MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>");
0083 MODULE_DESCRIPTION("Synopsys AXS10x reset driver");
0084 MODULE_LICENSE("GPL v2");