diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 16:50:35 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 16:50:35 -0800 |
commit | 3c0cb7c31c206aaedb967e44b98442bbeb17a6c4 (patch) | |
tree | 3ecba45d7ffae4fba4a5aafaef4af5b0b1105bde /arch/arm/mach-mxs/system.c | |
parent | f70f5b9dc74ca7d0a64c4ead3fb28da09dc1b234 (diff) | |
parent | 404a02cbd2ae8bf256a2fa1169bdfe86bb5ebb34 (diff) |
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
Diffstat (limited to 'arch/arm/mach-mxs/system.c')
-rw-r--r-- | arch/arm/mach-mxs/system.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/arm/mach-mxs/system.c b/arch/arm/mach-mxs/system.c new file mode 100644 index 00000000000..9343d7edd4f --- /dev/null +++ b/arch/arm/mach-mxs/system.c @@ -0,0 +1,137 @@ +/* + * 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 + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/init.h> + +#include <asm/proc-fns.h> +#include <asm/system.h> + +#include <mach/mxs.h> +#include <mach/common.h> + +#define MX23_CLKCTRL_RESET_OFFSET 0x120 +#define MX28_CLKCTRL_RESET_OFFSET 0x1e0 +#define MXS_CLKCTRL_RESET_CHIP (1 << 1) + +#define MXS_MODULE_CLKGATE (1 << 30) +#define MXS_MODULE_SFTRST (1 << 31) + +static void __iomem *mxs_clkctrl_reset_addr; + +/* + * Reset the system. It is called by machine_restart(). + */ +void arch_reset(char mode, const char *cmd) +{ + /* reset the chip */ + __mxs_setl(MXS_CLKCTRL_RESET_CHIP, mxs_clkctrl_reset_addr); + + pr_err("Failed to assert the chip reset\n"); + + /* Delay to allow the serial port to show the message */ + mdelay(50); + + /* We'll take a jump through zero as a poor second */ + cpu_reset(0); +} + +static int __init mxs_arch_reset_init(void) +{ + struct clk *clk; + + mxs_clkctrl_reset_addr = MXS_IO_ADDRESS(MXS_CLKCTRL_BASE_ADDR) + + (cpu_is_mx23() ? MX23_CLKCTRL_RESET_OFFSET : + MX28_CLKCTRL_RESET_OFFSET); + + clk = clk_get_sys("rtc", NULL); + if (!IS_ERR(clk)) + clk_enable(clk); + + return 0; +} +core_initcall(mxs_arch_reset_init); + +/* + * 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 clear_poll_bit(void __iomem *addr, u32 mask) +{ + int timeout = 0x400; + + /* clear the bit */ + __mxs_clrl(mask, addr); + + /* + * SFTRST needs 3 GPMI clocks to settle, the reference manual + * recommends to wait 1us. + */ + udelay(1); + + /* poll the bit becoming clear */ + while ((__raw_readl(addr) & mask) && --timeout) + /* nothing */; + + return !timeout; +} + +int mxs_reset_block(void __iomem *reset_addr) +{ + int ret; + int timeout = 0x400; + + /* clear and poll SFTRST */ + ret = clear_poll_bit(reset_addr, MXS_MODULE_SFTRST); + if (unlikely(ret)) + goto error; + + /* clear CLKGATE */ + __mxs_clrl(MXS_MODULE_CLKGATE, reset_addr); + + /* set SFTRST to reset the block */ + __mxs_setl(MXS_MODULE_SFTRST, reset_addr); + udelay(1); + + /* poll CLKGATE becoming set */ + while ((!(__raw_readl(reset_addr) & MXS_MODULE_CLKGATE)) && --timeout) + /* nothing */; + if (unlikely(!timeout)) + goto error; + + /* clear and poll SFTRST */ + ret = clear_poll_bit(reset_addr, MXS_MODULE_SFTRST); + if (unlikely(ret)) + goto error; + + /* clear and poll CLKGATE */ + ret = clear_poll_bit(reset_addr, MXS_MODULE_CLKGATE); + if (unlikely(ret)) + goto error; + + return 0; + +error: + pr_err("%s(%p): module reset timeout\n", __func__, reset_addr); + return -ETIMEDOUT; +} |