169bfec75SEmil Renner Berthing // SPDX-License-Identifier: GPL-2.0-or-later
269bfec75SEmil Renner Berthing /*
369bfec75SEmil Renner Berthing * Reset driver for the StarFive JH7100 SoC
469bfec75SEmil Renner Berthing *
569bfec75SEmil Renner Berthing * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
669bfec75SEmil Renner Berthing */
769bfec75SEmil Renner Berthing
869bfec75SEmil Renner Berthing #include <linux/mod_devicetable.h>
969bfec75SEmil Renner Berthing #include <linux/platform_device.h>
1069bfec75SEmil Renner Berthing
111ec3d20eSEmil Renner Berthing #include "reset-starfive-jh71x0.h"
1269bfec75SEmil Renner Berthing
13ed36fcd1SEmil Renner Berthing #include <dt-bindings/reset/starfive-jh7100.h>
14ed36fcd1SEmil Renner Berthing
15ed36fcd1SEmil Renner Berthing /* register offsets */
16ed36fcd1SEmil Renner Berthing #define JH7100_RESET_ASSERT0 0x00
17ed36fcd1SEmil Renner Berthing #define JH7100_RESET_ASSERT1 0x04
18ed36fcd1SEmil Renner Berthing #define JH7100_RESET_ASSERT2 0x08
19ed36fcd1SEmil Renner Berthing #define JH7100_RESET_ASSERT3 0x0c
20ed36fcd1SEmil Renner Berthing #define JH7100_RESET_STATUS0 0x10
21ed36fcd1SEmil Renner Berthing #define JH7100_RESET_STATUS1 0x14
22ed36fcd1SEmil Renner Berthing #define JH7100_RESET_STATUS2 0x18
23ed36fcd1SEmil Renner Berthing #define JH7100_RESET_STATUS3 0x1c
24ed36fcd1SEmil Renner Berthing
25ed36fcd1SEmil Renner Berthing /*
26ed36fcd1SEmil Renner Berthing * Writing a 1 to the n'th bit of the m'th ASSERT register asserts
27ed36fcd1SEmil Renner Berthing * line 32m + n, and writing a 0 deasserts the same line.
28ed36fcd1SEmil Renner Berthing * Most reset lines have their status inverted so a 0 bit in the STATUS
29ed36fcd1SEmil Renner Berthing * register means the line is asserted and a 1 means it's deasserted. A few
30ed36fcd1SEmil Renner Berthing * lines don't though, so store the expected value of the status registers when
31ed36fcd1SEmil Renner Berthing * all lines are asserted.
32ed36fcd1SEmil Renner Berthing */
33*b6d7406cSEmil Renner Berthing static const u32 jh7100_reset_asserted[4] = {
34ed36fcd1SEmil Renner Berthing /* STATUS0 */
35*b6d7406cSEmil Renner Berthing BIT(JH7100_RST_U74 % 32) |
36*b6d7406cSEmil Renner Berthing BIT(JH7100_RST_VP6_DRESET % 32) |
37*b6d7406cSEmil Renner Berthing BIT(JH7100_RST_VP6_BRESET % 32),
38ed36fcd1SEmil Renner Berthing /* STATUS1 */
39*b6d7406cSEmil Renner Berthing BIT(JH7100_RST_HIFI4_DRESET % 32) |
40*b6d7406cSEmil Renner Berthing BIT(JH7100_RST_HIFI4_BRESET % 32),
41ed36fcd1SEmil Renner Berthing /* STATUS2 */
42*b6d7406cSEmil Renner Berthing BIT(JH7100_RST_E24 % 32),
43ed36fcd1SEmil Renner Berthing /* STATUS3 */
44ed36fcd1SEmil Renner Berthing 0,
45ed36fcd1SEmil Renner Berthing };
46ed36fcd1SEmil Renner Berthing
jh7100_reset_probe(struct platform_device * pdev)47ed36fcd1SEmil Renner Berthing static int __init jh7100_reset_probe(struct platform_device *pdev)
48ed36fcd1SEmil Renner Berthing {
49ed36fcd1SEmil Renner Berthing void __iomem *base = devm_platform_ioremap_resource(pdev, 0);
50ed36fcd1SEmil Renner Berthing
51ed36fcd1SEmil Renner Berthing if (IS_ERR(base))
52ed36fcd1SEmil Renner Berthing return PTR_ERR(base);
53ed36fcd1SEmil Renner Berthing
540333103eSEmil Renner Berthing return reset_starfive_jh71x0_register(&pdev->dev, pdev->dev.of_node,
55ed36fcd1SEmil Renner Berthing base + JH7100_RESET_ASSERT0,
56ed36fcd1SEmil Renner Berthing base + JH7100_RESET_STATUS0,
57ed36fcd1SEmil Renner Berthing jh7100_reset_asserted,
58ed36fcd1SEmil Renner Berthing JH7100_RSTN_END,
59ed36fcd1SEmil Renner Berthing THIS_MODULE);
60ed36fcd1SEmil Renner Berthing }
61ed36fcd1SEmil Renner Berthing
6269bfec75SEmil Renner Berthing static const struct of_device_id jh7100_reset_dt_ids[] = {
6369bfec75SEmil Renner Berthing { .compatible = "starfive,jh7100-reset" },
6469bfec75SEmil Renner Berthing { /* sentinel */ }
6569bfec75SEmil Renner Berthing };
6669bfec75SEmil Renner Berthing
6769bfec75SEmil Renner Berthing static struct platform_driver jh7100_reset_driver = {
6869bfec75SEmil Renner Berthing .driver = {
6969bfec75SEmil Renner Berthing .name = "jh7100-reset",
7069bfec75SEmil Renner Berthing .of_match_table = jh7100_reset_dt_ids,
7169bfec75SEmil Renner Berthing .suppress_bind_attrs = true,
7269bfec75SEmil Renner Berthing },
7369bfec75SEmil Renner Berthing };
7469bfec75SEmil Renner Berthing builtin_platform_driver_probe(jh7100_reset_driver, jh7100_reset_probe);
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