diff options
Diffstat (limited to 'drivers/power/reset/oxnas-restart.c')
| -rw-r--r-- | drivers/power/reset/oxnas-restart.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/power/reset/oxnas-restart.c b/drivers/power/reset/oxnas-restart.c new file mode 100644 index 000000000..13090bec0 --- /dev/null +++ b/drivers/power/reset/oxnas-restart.c @@ -0,0 +1,233 @@ +// 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); |