Files
android/lib/stmp_device.c
threeeye bc1d038eac REVVL 6 Pro kernel bring-up: full working tree snapshot (2026-09-12)
Squashed backup commit (no shallow-clone history issues) of
xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream
commit 9eece662e) plus all fixes applied to get everpal_defconfig building
clean against a modern (GCC 15.2.0) toolchain -- see the previous commit
message on the lineage-23.2 branch (also in this repo history is not
available here since this is a squashed snapshot; full incremental history
lives in the local DL380 checkout and the upstream GitHub remote).

Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
2026-09-12 13:36:46 +00:00

82 lines
2.1 KiB
C

/*
* Copyright (C) 1999 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
* Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
* Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
* Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/compiler.h>
#include <linux/export.h>
#include <linux/stmp_device.h>
#define STMP_MODULE_CLKGATE (1 << 30)
#define STMP_MODULE_SFTRST (1 << 31)
/*
* Clear the bit and poll it cleared. This is usually called with
* a reset address and mask being either SFTRST(bit 31) or CLKGATE
* (bit 30).
*/
static int stmp_clear_poll_bit(void __iomem *addr, u32 mask)
{
int timeout = 0x400;
writel(mask, addr + STMP_OFFSET_REG_CLR);
udelay(1);
while ((readl(addr) & mask) && --timeout)
/* nothing */;
return !timeout;
}
int stmp_reset_block(void __iomem *reset_addr)
{
int ret;
int timeout = 0x400;
/* clear and poll SFTRST */
ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
if (unlikely(ret))
goto error;
/* clear CLKGATE */
writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR);
/* set SFTRST to reset the block */
writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);
udelay(1);
/* poll CLKGATE becoming set */
while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)
/* nothing */;
if (unlikely(!timeout))
goto error;
/* clear and poll SFTRST */
ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
if (unlikely(ret))
goto error;
/* clear and poll CLKGATE */
ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);
if (unlikely(ret))
goto error;
return 0;
error:
pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
return -ETIMEDOUT;
}
EXPORT_SYMBOL(stmp_reset_block);