--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0)
+/*
+ * oxnas SoC reset driver
+ * based on:
+ * Microsemi MIPS SoC reset driver
+ * and ox820_assert_system_reset() written by Ma Hajun <mahaijuns@gmail.com>
+ *
+ * Copyright (c) 2013 Ma Hajun <mahaijuns@gmail.com>
+ * Copyright (c) 2017 Microsemi Corporation
+ * Copyright (c) 2020 Daniel Golle <daniel@makrotopia.org>
+ */
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+/* bit numbers of reset control register */
+#define OX820_SYS_CTRL_RST_SCU 0
+#define OX820_SYS_CTRL_RST_COPRO 1
+#define OX820_SYS_CTRL_RST_ARM0 2
+#define OX820_SYS_CTRL_RST_ARM1 3
+#define OX820_SYS_CTRL_RST_USBHS 4
+#define OX820_SYS_CTRL_RST_USBHSPHYA 5
+#define OX820_SYS_CTRL_RST_MACA 6
+#define OX820_SYS_CTRL_RST_MAC OX820_SYS_CTRL_RST_MACA
+#define OX820_SYS_CTRL_RST_PCIEA 7
+#define OX820_SYS_CTRL_RST_SGDMA 8
+#define OX820_SYS_CTRL_RST_CIPHER 9
+#define OX820_SYS_CTRL_RST_DDR 10
+#define OX820_SYS_CTRL_RST_SATA 11
+#define OX820_SYS_CTRL_RST_SATA_LINK 12
+#define OX820_SYS_CTRL_RST_SATA_PHY 13
+#define OX820_SYS_CTRL_RST_PCIEPHY 14
+#define OX820_SYS_CTRL_RST_STATIC 15
+#define OX820_SYS_CTRL_RST_GPIO 16
+#define OX820_SYS_CTRL_RST_UART1 17
+#define OX820_SYS_CTRL_RST_UART2 18
+#define OX820_SYS_CTRL_RST_MISC 19
+#define OX820_SYS_CTRL_RST_I2S 20
+#define OX820_SYS_CTRL_RST_SD 21
+#define OX820_SYS_CTRL_RST_MACB 22
+#define OX820_SYS_CTRL_RST_PCIEB 23
+#define OX820_SYS_CTRL_RST_VIDEO 24
+#define OX820_SYS_CTRL_RST_DDR_PHY 25
+#define OX820_SYS_CTRL_RST_USBHSPHYB 26
+#define OX820_SYS_CTRL_RST_USBDEV 27
+#define OX820_SYS_CTRL_RST_ARMDBG 29
+#define OX820_SYS_CTRL_RST_PLLA 30
+#define OX820_SYS_CTRL_RST_PLLB 31
+
+/* bit numbers of clock control register */
+#define OX820_SYS_CTRL_CLK_COPRO 0
+#define OX820_SYS_CTRL_CLK_DMA 1
+#define OX820_SYS_CTRL_CLK_CIPHER 2
+#define OX820_SYS_CTRL_CLK_SD 3
+#define OX820_SYS_CTRL_CLK_SATA 4
+#define OX820_SYS_CTRL_CLK_I2S 5
+#define OX820_SYS_CTRL_CLK_USBHS 6
+#define OX820_SYS_CTRL_CLK_MACA 7
+#define OX820_SYS_CTRL_CLK_MAC OX820_SYS_CTRL_CLK_MACA
+#define OX820_SYS_CTRL_CLK_PCIEA 8
+#define OX820_SYS_CTRL_CLK_STATIC 9
+#define OX820_SYS_CTRL_CLK_MACB 10
+#define OX820_SYS_CTRL_CLK_PCIEB 11
+#define OX820_SYS_CTRL_CLK_REF600 12
+#define OX820_SYS_CTRL_CLK_USBDEV 13
+#define OX820_SYS_CTRL_CLK_DDR 14
+#define OX820_SYS_CTRL_CLK_DDRPHY 15
+#define OX820_SYS_CTRL_CLK_DDRCK 16
+
+/* Regmap offsets */
+#define OX820_CLK_SET_REGOFFSET 0x2c
+#define OX820_CLK_CLR_REGOFFSET 0x30
+#define OX820_RST_SET_REGOFFSET 0x34
+#define OX820_RST_CLR_REGOFFSET 0x38
+#define OX820_SECONDARY_SEL_REGOFFSET 0x14
+#define OX820_TERTIARY_SEL_REGOFFSET 0x8c
+#define OX820_QUATERNARY_SEL_REGOFFSET 0x94
+#define OX820_DEBUG_SEL_REGOFFSET 0x9c
+#define OX820_ALTERNATIVE_SEL_REGOFFSET 0xa4
+#define OX820_PULLUP_SEL_REGOFFSET 0xac
+#define OX820_SEC_SECONDARY_SEL_REGOFFSET 0x100014
+#define OX820_SEC_TERTIARY_SEL_REGOFFSET 0x10008c
+#define OX820_SEC_QUATERNARY_SEL_REGOFFSET 0x100094
+#define OX820_SEC_DEBUG_SEL_REGOFFSET 0x10009c
+#define OX820_SEC_ALTERNATIVE_SEL_REGOFFSET 0x1000a4
+#define OX820_SEC_PULLUP_SEL_REGOFFSET 0x1000ac
+
+struct oxnas_restart_context {
+ struct regmap *sys_ctrl;
+ struct notifier_block restart_handler;
+};
+
+static int ox820_restart_handle(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct oxnas_restart_context *ctx = container_of(this, struct
+ oxnas_restart_context,
+ restart_handler);
+ u32 value;
+
+ /*
+ * Assert reset to cores as per power on defaults
+ * Don't touch the DDR interface as things will come to an impromptu
+ * stop NB Possibly should be asserting reset for PLLB, but there are
+ * timing concerns here according to the docs
+ */
+ value = BIT(OX820_SYS_CTRL_RST_COPRO) |
+ BIT(OX820_SYS_CTRL_RST_USBHS) |
+ BIT(OX820_SYS_CTRL_RST_USBHSPHYA) |
+ BIT(OX820_SYS_CTRL_RST_MACA) |
+ BIT(OX820_SYS_CTRL_RST_PCIEA) |
+ BIT(OX820_SYS_CTRL_RST_SGDMA) |
+ BIT(OX820_SYS_CTRL_RST_CIPHER) |
+ BIT(OX820_SYS_CTRL_RST_SATA) |
+ BIT(OX820_SYS_CTRL_RST_SATA_LINK) |
+ BIT(OX820_SYS_CTRL_RST_SATA_PHY) |
+ BIT(OX820_SYS_CTRL_RST_PCIEPHY) |
+ BIT(OX820_SYS_CTRL_RST_STATIC) |
+ BIT(OX820_SYS_CTRL_RST_UART1) |
+ BIT(OX820_SYS_CTRL_RST_UART2) |
+ BIT(OX820_SYS_CTRL_RST_MISC) |
+ BIT(OX820_SYS_CTRL_RST_I2S) |
+ BIT(OX820_SYS_CTRL_RST_SD) |
+ BIT(OX820_SYS_CTRL_RST_MACB) |
+ BIT(OX820_SYS_CTRL_RST_PCIEB) |
+ BIT(OX820_SYS_CTRL_RST_VIDEO) |
+ BIT(OX820_SYS_CTRL_RST_USBHSPHYB) |
+ BIT(OX820_SYS_CTRL_RST_USBDEV);
+
+ regmap_write(ctx->sys_ctrl, OX820_RST_SET_REGOFFSET, value);
+
+ /* Release reset to cores as per power on defaults */
+ regmap_write(ctx->sys_ctrl, OX820_RST_CLR_REGOFFSET,
+ BIT(OX820_SYS_CTRL_RST_GPIO));
+
+ /*
+ * Disable clocks to cores as per power-on defaults - must leave DDR
+ * related clocks enabled otherwise we'll stop rather abruptly.
+ */
+ value = BIT(OX820_SYS_CTRL_CLK_COPRO) |
+ BIT(OX820_SYS_CTRL_CLK_DMA) |
+ BIT(OX820_SYS_CTRL_CLK_CIPHER) |
+ BIT(OX820_SYS_CTRL_CLK_SD) |
+ BIT(OX820_SYS_CTRL_CLK_SATA) |
+ BIT(OX820_SYS_CTRL_CLK_I2S) |
+ BIT(OX820_SYS_CTRL_CLK_USBHS) |
+ BIT(OX820_SYS_CTRL_CLK_MAC) |
+ BIT(OX820_SYS_CTRL_CLK_PCIEA) |
+ BIT(OX820_SYS_CTRL_CLK_STATIC) |
+ BIT(OX820_SYS_CTRL_CLK_MACB) |
+ BIT(OX820_SYS_CTRL_CLK_PCIEB) |
+ BIT(OX820_SYS_CTRL_CLK_REF600) |
+ BIT(OX820_SYS_CTRL_CLK_USBDEV);
+
+ regmap_write(ctx->sys_ctrl, OX820_CLK_CLR_REGOFFSET, value);
+
+ /* Enable clocks to cores as per power-on defaults */
+
+ /* Set sys-control pin mux'ing as per power-on defaults */
+ regmap_write(ctx->sys_ctrl, OX820_SECONDARY_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_TERTIARY_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_QUATERNARY_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_DEBUG_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_ALTERNATIVE_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_PULLUP_SEL_REGOFFSET, 0);
+
+ regmap_write(ctx->sys_ctrl, OX820_SEC_SECONDARY_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_SEC_TERTIARY_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_SEC_QUATERNARY_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_SEC_DEBUG_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_SEC_ALTERNATIVE_SEL_REGOFFSET, 0);
+ regmap_write(ctx->sys_ctrl, OX820_SEC_PULLUP_SEL_REGOFFSET, 0);
+
+ /*
+ * No need to save any state, as the ROM loader can determine whether
+ * reset is due to power cycling or programatic action, just hit the
+ * (self-clearing) CPU reset bit of the block reset register
+ */
+ value =
+ BIT(OX820_SYS_CTRL_RST_SCU) |
+ BIT(OX820_SYS_CTRL_RST_ARM0) |
+ BIT(OX820_SYS_CTRL_RST_ARM1);
+
+ regmap_write(ctx->sys_ctrl, OX820_RST_SET_REGOFFSET, value);
+
+ pr_emerg("Unable to restart system\n");
+ return NOTIFY_DONE;
+}
+
+static int ox820_restart_probe(struct platform_device *pdev)
+{
+ struct oxnas_restart_context *ctx;
+ struct regmap *sys_ctrl;
+ struct device *dev = &pdev->dev;
+ int err = 0;
+
+ sys_ctrl = syscon_node_to_regmap(pdev->dev.of_node);
+ if (IS_ERR(sys_ctrl))
+ return PTR_ERR(sys_ctrl);
+
+ ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->sys_ctrl = sys_ctrl;
+ ctx->restart_handler.notifier_call = ox820_restart_handle;
+ ctx->restart_handler.priority = 192;
+ err = register_restart_handler(&ctx->restart_handler);
+ if (err)
+ dev_err(dev, "can't register restart notifier (err=%d)\n", err);
+
+ return err;
+}
+
+static const struct of_device_id ox820_restart_of_match[] = {
+ { .compatible = "oxsemi,ox820-sys-ctrl" },
+ {}
+};
+
+static struct platform_driver ox820_restart_driver = {
+ .probe = ox820_restart_probe,
+ .driver = {
+ .name = "ox820-chip-reset",
+ .of_match_table = ox820_restart_of_match,
+ },
+};
+builtin_platform_driver(ox820_restart_driver);
projects / platform / kernel / linux-starfive.git / commitdiff