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linux-next/drivers/power/reset/oxnas-restart.c
Daniel Golle 0edb259c98 power: reset: introduce oxnas-restart
Add reboot handler for Oxford OX820 chips as reboot currenly hangs on
those boards. Code is based on ox820_assert_system_reset() found in
https://github.com/kref/linux-oxnas.git in
arch/arm/mach-oxnas/mach-ox820.c line 181.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2020-04-30 23:24:33 +02:00

234 lines
8.4 KiB
C

// 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);