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On BCM7216 there is a special purpose reset controller named RESCAL (reset calibration) which is necessary for SATA and PCIe0/1 to operate correctly. This commit adds support for such a reset controller to be available. Signed-off-by: Jim Quinlan <jim2101024@gmail.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (C) 2018-2020 Broadcom */
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#include <linux/device.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/reset-controller.h>
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#define BRCM_RESCAL_START 0x0
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#define BRCM_RESCAL_START_BIT BIT(0)
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#define BRCM_RESCAL_CTRL 0x4
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#define BRCM_RESCAL_STATUS 0x8
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#define BRCM_RESCAL_STATUS_BIT BIT(0)
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struct brcm_rescal_reset {
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void __iomem *base;
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struct device *dev;
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struct reset_controller_dev rcdev;
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};
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static int brcm_rescal_reset_set(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct brcm_rescal_reset *data =
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container_of(rcdev, struct brcm_rescal_reset, rcdev);
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void __iomem *base = data->base;
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u32 reg;
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int ret;
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reg = readl(base + BRCM_RESCAL_START);
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writel(reg | BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);
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reg = readl(base + BRCM_RESCAL_START);
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if (!(reg & BRCM_RESCAL_START_BIT)) {
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dev_err(data->dev, "failed to start SATA/PCIe rescal\n");
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return -EIO;
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}
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ret = readl_poll_timeout(base + BRCM_RESCAL_STATUS, reg,
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!(reg & BRCM_RESCAL_STATUS_BIT), 100, 1000);
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if (ret) {
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dev_err(data->dev, "time out on SATA/PCIe rescal\n");
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return ret;
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}
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reg = readl(base + BRCM_RESCAL_START);
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writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);
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dev_dbg(data->dev, "SATA/PCIe rescal success\n");
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return 0;
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}
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static int brcm_rescal_reset_xlate(struct reset_controller_dev *rcdev,
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const struct of_phandle_args *reset_spec)
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{
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/* This is needed if #reset-cells == 0. */
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return 0;
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}
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static const struct reset_control_ops brcm_rescal_reset_ops = {
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.reset = brcm_rescal_reset_set,
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};
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static int brcm_rescal_reset_probe(struct platform_device *pdev)
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{
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struct brcm_rescal_reset *data;
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struct resource *res;
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data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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data->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(data->base))
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return PTR_ERR(data->base);
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data->rcdev.owner = THIS_MODULE;
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data->rcdev.nr_resets = 1;
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data->rcdev.ops = &brcm_rescal_reset_ops;
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data->rcdev.of_node = pdev->dev.of_node;
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data->rcdev.of_xlate = brcm_rescal_reset_xlate;
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data->dev = &pdev->dev;
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return devm_reset_controller_register(&pdev->dev, &data->rcdev);
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}
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static const struct of_device_id brcm_rescal_reset_of_match[] = {
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{ .compatible = "brcm,bcm7216-pcie-sata-rescal" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, brcm_rescal_reset_of_match);
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static struct platform_driver brcm_rescal_reset_driver = {
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.probe = brcm_rescal_reset_probe,
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.driver = {
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.name = "brcm-rescal-reset",
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.of_match_table = brcm_rescal_reset_of_match,
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}
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};
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module_platform_driver(brcm_rescal_reset_driver);
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MODULE_AUTHOR("Broadcom");
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MODULE_DESCRIPTION("Broadcom SATA/PCIe rescal reset controller");
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MODULE_LICENSE("GPL v2");
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