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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 16:50:35 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 16:50:35 -0800
commit3c0cb7c31c206aaedb967e44b98442bbeb17a6c4 (patch)
tree3ecba45d7ffae4fba4a5aafaef4af5b0b1105bde /arch/arm/mach-mxs/system.c
parentf70f5b9dc74ca7d0a64c4ead3fb28da09dc1b234 (diff)
parent404a02cbd2ae8bf256a2fa1169bdfe86bb5ebb34 (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.c137
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;
+}