- 根目录:
- arch
- arm
- mach-kirkwood
- common.c
/*
* arch/arm/mach-kirkwood/common.c
*
* Core functions for Marvell Kirkwood SoCs
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/serial_8250.h>
#include <linux/ata_platform.h>
#include <linux/mtd/nand.h>
#include <linux/dma-mapping.h>
#include <linux/clk-provider.h>
#include <linux/spinlock.h>
#include <linux/mv643xx_i2c.h>
#include <linux/timex.h>
#include <linux/kexec.h>
#include <net/dsa.h>
#include <asm/page.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#include <mach/kirkwood.h>
#include <mach/bridge-regs.h>
#include <linux/platform_data/asoc-kirkwood.h>
#include <plat/cache-feroceon-l2.h>
#include <linux/platform_data/mmc-mvsdio.h>
#include <linux/platform_data/mtd-orion_nand.h>
#include <linux/platform_data/usb-ehci-orion.h>
#include <plat/common.h>
#include <plat/time.h>
#include <linux/platform_data/dma-mv_xor.h>
#include "common.h"
/*****************************************************************************
* I/O Address Mapping
****************************************************************************/
static struct map_desc kirkwood_io_desc[] __initdata = {
{
.virtual = (unsigned long) KIRKWOOD_REGS_VIRT_BASE,
.pfn = __phys_to_pfn(KIRKWOOD_REGS_PHYS_BASE),
.length = KIRKWOOD_REGS_SIZE,
.type = MT_DEVICE,
},
};
void __init kirkwood_map_io(void)
{
iotable_init(kirkwood_io_desc, ARRAY_SIZE(kirkwood_io_desc));
}
/*****************************************************************************
* CLK tree
****************************************************************************/
static void enable_sata0(void)
{
/* Enable PLL and IVREF */
writel(readl(SATA0_PHY_MODE_2) | 0xf, SATA0_PHY_MODE_2);
/* Enable PHY */
writel(readl(SATA0_IF_CTRL) & ~0x200, SATA0_IF_CTRL);
}
static void disable_sata0(void)
{
/* Disable PLL and IVREF */
writel(readl(SATA0_PHY_MODE_2) & ~0xf, SATA0_PHY_MODE_2);
/* Disable PHY */
writel(readl(SATA0_IF_CTRL) | 0x200, SATA0_IF_CTRL);
}
static void enable_sata1(void)
{
/* Enable PLL and IVREF */
writel(readl(SATA1_PHY_MODE_2) | 0xf, SATA1_PHY_MODE_2);
/* Enable PHY */
writel(readl(SATA1_IF_CTRL) & ~0x200, SATA1_IF_CTRL);
}
static void disable_sata1(void)
{
/* Disable PLL and IVREF */
writel(readl(SATA1_PHY_MODE_2) & ~0xf, SATA1_PHY_MODE_2);
/* Disable PHY */
writel(readl(SATA1_IF_CTRL) | 0x200, SATA1_IF_CTRL);
}
static void disable_pcie0(void)
{
writel(readl(PCIE_LINK_CTRL) | 0x10, PCIE_LINK_CTRL);
while (1)
if (readl(PCIE_STATUS) & 0x1)
break;
writel(readl(PCIE_LINK_CTRL) & ~0x10, PCIE_LINK_CTRL);
}
static void disable_pcie1(void)
{
u32 dev, rev;
kirkwood_pcie_id(&dev, &rev);
if (dev == MV88F6282_DEV_ID) {
writel(readl(PCIE1_LINK_CTRL) | 0x10, PCIE1_LINK_CTRL);
while (1)
if (readl(PCIE1_STATUS) & 0x1)
break;
writel(readl(PCIE1_LINK_CTRL) & ~0x10, PCIE1_LINK_CTRL);
}
}
/* An extended version of the gated clk. This calls fn_en()/fn_dis
* before enabling/disabling the clock. We use this to turn on/off
* PHYs etc. */
struct clk_gate_fn {
struct clk_gate gate;
void (*fn_en)(void);
void (*fn_dis)(void);
};
#define to_clk_gate_fn(_gate) container_of(_gate, struct clk_gate_fn, gate)
#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
static int clk_gate_fn_enable(struct clk_hw *hw)
{
struct clk_gate *gate = to_clk_gate(hw);
struct clk_gate_fn *gate_fn = to_clk_gate_fn(gate);
int ret;
ret = clk_gate_ops.enable(hw);
if (!ret && gate_fn->fn_en)
gate_fn->fn_en();
return ret;
}
static void clk_gate_fn_disable(struct clk_hw *hw)
{
struct clk_gate *gate = to_clk_gate(hw);
struct clk_gate_fn *gate_fn = to_clk_gate_fn(gate);
if (gate_fn->fn_dis)
gate_fn->fn_dis();
clk_gate_ops.disable(hw);
}
static struct clk_ops clk_gate_fn_ops;
static struct clk __init *clk_register_gate_fn(struct device *dev,
const char *name,
const char *parent_name, unsigned long flags,
void __iomem *reg, u8 bit_idx,
u8 clk_gate_flags, spinlock_t *lock,
void (*fn_en)(void), void (*fn_dis)(void))
{
struct clk_gate_fn *gate_fn;
struct clk *clk;
struct clk_init_data init;
gate_fn = kzalloc(sizeof(struct clk_gate_fn), GFP_KERNEL);
if (!gate_fn) {
pr_err("%s: could not allocate gated clk\n", __func__);
return ERR_PTR(-ENOMEM);
}
init.name = name;
init.ops = &clk_gate_fn_ops;
init.flags = flags;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
/* struct clk_gate assignments */
gate_fn->gate.reg = reg;
gate_fn->gate.bit_idx = bit_idx;
gate_fn->gate.flags = clk_gate_flags;
gate_fn->gate.lock = lock;
gate_fn->gate.hw.init = &init;
gate_fn->fn_en = fn_en;
gate_fn->fn_dis = fn_dis;
/* ops is the gate ops, but with our enable/disable functions */
if (clk_gate_fn_ops.enable != clk_gate_fn_enable ||
clk_gate_fn_ops.disable != clk_gate_fn_disable) {
clk_gate_fn_ops = clk_gate_ops;
clk_gate_fn_ops.enable = clk_gate_fn_enable;
clk_gate_fn_ops.disable = clk_gate_fn_disable;
}
clk = clk_register(dev, &gate_fn->gate.hw);
if (IS_ERR(clk))
kfree(gate_fn);
return clk;
}
static DEFINE_SPINLOCK(gating_lock);
static struct clk *tclk;
static struct clk __init *kirkwood_register_gate(const char *name, u8 bit_idx)
{
return clk_register_gate(NULL, name, "tclk", 0, CLOCK_GATING_CTRL,
bit_idx, 0, &gating_lock);
}
static struct clk __init *kirkwood_register_gate_fn(const char *name,
u8 bit_idx,
void (*fn_en)(void),
void (*fn_dis)(void))
{
return clk_register_gate_fn(NULL, name, "tclk", 0, CLOCK_GATING_CTRL,
bit_idx, 0, &gating_lock, fn_en, fn_dis);
}
static struct clk *ge0, *ge1;
void __init kirkwood_clk_init(void)
{
struct clk *runit, *sata0, *sata1, *usb0, *sdio;
struct clk *crypto, *xor0, *xor1, *pex0, *pex1, *audio;
tclk = clk_register_fixed_rate(NULL, "tclk", NULL,
CLK_IS_ROOT, kirkwood_tclk);
runit = kirkwood_register_gate("runit", CGC_BIT_RUNIT);
ge0 = kirkwood_register_gate("ge0", CGC_BIT_GE0);
ge1 = kirkwood_register_gate("ge1", CGC_BIT_GE1);
sata0 = kirkwood_register_gate_fn("sata0", CGC_BIT_SATA0,
enable_sata0, disable_sata0);
sata1 = kirkwood_register_gate_fn("sata1", CGC_BIT_SATA1,
enable_sata1, disable_sata1);
usb0 = kirkwood_register_gate("usb0", CGC_BIT_USB0);
sdio = kirkwood_register_gate("sdio", CGC_BIT_SDIO);
crypto = kirkwood_register_gate("crypto", CGC_BIT_CRYPTO);
xor0 = kirkwood_register_gate("xor0", CGC_BIT_XOR0);
xor1 = kirkwood_register_gate("xor1", CGC_BIT_XOR1);
pex0 = kirkwood_register_gate_fn("pex0", CGC_BIT_PEX0,
NULL, disable_pcie0);
pex1 = kirkwood_register_gate_fn("pex1", CGC_BIT_PEX1,
NULL, disable_pcie1);
audio = kirkwood_register_gate("audio", CGC_BIT_AUDIO);
kirkwood_register_gate("tdm", CGC_BIT_TDM);
kirkwood_register_gate("tsu", CGC_BIT_TSU);
/* clkdev entries, mapping clks to devices */
orion_clkdev_add(NULL, "orion_spi.0", runit);
orion_clkdev_add(NULL, "orion_spi.1", runit);
orion_clkdev_add(NULL, MV643XX_ETH_NAME ".0", ge0);
orion_clkdev_add(NULL, MV643XX_ETH_NAME ".1", ge1);
orion_clkdev_add(NULL, "orion_wdt", tclk);
orion_clkdev_add("0", "sata_mv.0", sata0);
orion_clkdev_add("1", "sata_mv.0", sata1);
orion_clkdev_add(NULL, "orion-ehci.0", usb0);
orion_clkdev_add(NULL, "orion_nand", runit);
orion_clkdev_add(NULL, "mvsdio", sdio);
orion_clkdev_add(NULL, "mv_crypto", crypto);
orion_clkdev_add(NULL, MV_XOR_NAME ".0", xor0);
orion_clkdev_add(NULL, MV_XOR_NAME ".1", xor1);
orion_clkdev_add("0", "pcie", pex0);
orion_clkdev_add("1", "pcie", pex1);
orion_clkdev_add(NULL, "kirkwood-i2s", audio);
orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".0", runit);
orion_clkdev_add(NULL, MV64XXX_I2C_CTLR_NAME ".1", runit);
/* Marvell says runit is used by SPI, UART, NAND, TWSI, ...,
* so should never be gated.
*/
clk_prepare_enable(runit);
}
/*****************************************************************************
* EHCI0
****************************************************************************/
void __init kirkwood_ehci_init(void)
{
orion_ehci_init(USB_PHYS_BASE, IRQ_KIRKWOOD_USB, EHCI_PHY_NA);
}
/*****************************************************************************
* GE00
****************************************************************************/
void __init kirkwood_ge00_init(struct mv643xx_eth_platform_data *eth_data)
{
orion_ge00_init(eth_data,
GE00_PHYS_BASE, IRQ_KIRKWOOD_GE00_SUM,
IRQ_KIRKWOOD_GE00_ERR, 1600);
/* The interface forgets the MAC address assigned by u-boot if
the clock is turned off, so claim the clk now. */
clk_prepare_enable(ge0);
}
/*****************************************************************************
* GE01
****************************************************************************/
void __init kirkwood_ge01_init(struct mv643xx_eth_platform_data *eth_data)
{
orion_ge01_init(eth_data,
GE01_PHYS_BASE, IRQ_KIRKWOOD_GE01_SUM,
IRQ_KIRKWOOD_GE01_ERR, 1600);
clk_prepare_enable(ge1);
}
/*****************************************************************************
* Ethernet switch
****************************************************************************/
void __init kirkwood_ge00_switch_init(struct dsa_platform_data *d, int irq)
{
orion_ge00_switch_init(d, irq);
}
/*****************************************************************************
* NAND flash
****************************************************************************/
static struct resource kirkwood_nand_resource = {
.flags = IORESOURCE_MEM,
.start = KIRKWOOD_NAND_MEM_PHYS_BASE,
.end = KIRKWOOD_NAND_MEM_PHYS_BASE +
KIRKWOOD_NAND_MEM_SIZE - 1,
};
static struct orion_nand_data kirkwood_nand_data = {
.cle = 0,
.ale = 1,
.width = 8,
};
static struct platform_device kirkwood_nand_flash = {
.name = "orion_nand",
.id = -1,
.dev = {
.platform_data = &kirkwood_nand_data,
},
.resource = &kirkwood_nand_resource,
.num_resources = 1,
};
void __init kirkwood_nand_init(struct mtd_partition *parts, int nr_parts,
int chip_delay)
{
kirkwood_nand_data.parts = parts;
kirkwood_nand_data.nr_parts = nr_parts;
kirkwood_nand_data.chip_delay = chip_delay;
platform_device_register(&kirkwood_nand_flash);
}
void __init kirkwood_nand_init_rnb(struct mtd_partition *parts, int nr_parts,
int (*dev_ready)(struct mtd_info *))
{
kirkwood_nand_data.parts = parts;
kirkwood_nand_data.nr_parts = nr_parts;
kirkwood_nand_data.dev_ready = dev_ready;
platform_device_register(&kirkwood_nand_flash);
}
/*****************************************************************************
* SoC RTC
****************************************************************************/
static void __init kirkwood_rtc_init(void)
{
orion_rtc_init(RTC_PHYS_BASE, IRQ_KIRKWOOD_RTC);
}
/*****************************************************************************
* SATA
****************************************************************************/
void __init kirkwood_sata_init(struct mv_sata_platform_data *sata_data)
{
orion_sata_init(sata_data, SATA_PHYS_BASE, IRQ_KIRKWOOD_SATA);
}
/*****************************************************************************
* SD/SDIO/MMC
****************************************************************************/
static struct resource mvsdio_resources[] = {
[0] = {
.start = SDIO_PHYS_BASE,
.end = SDIO_PHYS_BASE + SZ_1K - 1,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_KIRKWOOD_SDIO,
.end = IRQ_KIRKWOOD_SDIO,
.flags = IORESOURCE_IRQ,
},
};
static u64 mvsdio_dmamask = DMA_BIT_MASK(32);
static struct platform_device kirkwood_sdio = {
.name = "mvsdio",
.id = -1,
.dev = {
.dma_mask = &mvsdio_dmamask,
.coherent_dma_mask = DMA_BIT_MASK(32),
},
.num_resources = ARRAY_SIZE(mvsdio_resources),
.resource = mvsdio_resources,
};
void __init kirkwood_sdio_init(struct mvsdio_platform_data *mvsdio_data)
{
u32 dev, rev;
kirkwood_pcie_id(&dev, &rev);
if (rev == 0 && dev != MV88F6282_DEV_ID) /* catch all Kirkwood Z0's */
mvsdio_data->clock = 100000000;
else
mvsdio_data->clock = 200000000;
kirkwood_sdio.dev.platform_data = mvsdio_data;
platform_device_register(&kirkwood_sdio);
}
/*****************************************************************************
* SPI
****************************************************************************/
void __init kirkwood_spi_init(void)
{
orion_spi_init(SPI_PHYS_BASE);
}
/*****************************************************************************
* I2C
****************************************************************************/
void __init kirkwood_i2c_init(void)
{
orion_i2c_init(I2C_PHYS_BASE, IRQ_KIRKWOOD_TWSI, 8);
}
/*****************************************************************************
* UART0
****************************************************************************/
void __init kirkwood_uart0_init(void)
{
orion_uart0_init(UART0_VIRT_BASE, UART0_PHYS_BASE,
IRQ_KIRKWOOD_UART_0, tclk);
}
/*****************************************************************************
* UART1
****************************************************************************/
void __init kirkwood_uart1_init(void)
{
orion_uart1_init(UART1_VIRT_BASE, UART1_PHYS_BASE,
IRQ_KIRKWOOD_UART_1, tclk);
}
/*****************************************************************************
* Cryptographic Engines and Security Accelerator (CESA)
****************************************************************************/
void __init kirkwood_crypto_init(void)
{
orion_crypto_init(CRYPTO_PHYS_BASE, KIRKWOOD_SRAM_PHYS_BASE,
KIRKWOOD_SRAM_SIZE, IRQ_KIRKWOOD_CRYPTO);
}
/*****************************************************************************
* XOR0
****************************************************************************/
void __init kirkwood_xor0_init(void)
{
orion_xor0_init(XOR0_PHYS_BASE, XOR0_HIGH_PHYS_BASE,
IRQ_KIRKWOOD_XOR_00, IRQ_KIRKWOOD_XOR_01);
}
/*****************************************************************************
* XOR1
****************************************************************************/
void __init kirkwood_xor1_init(void)
{
orion_xor1_init(XOR1_PHYS_BASE, XOR1_HIGH_PHYS_BASE,
IRQ_KIRKWOOD_XOR_10, IRQ_KIRKWOOD_XOR_11);
}
/*****************************************************************************
* Watchdog
****************************************************************************/
void __init kirkwood_wdt_init(void)
{
orion_wdt_init();
}
/*****************************************************************************
* CPU idle
****************************************************************************/
static struct resource kirkwood_cpuidle_resource[] = {
{
.flags = IORESOURCE_MEM,
.start = DDR_OPERATION_BASE,
.end = DDR_OPERATION_BASE + 3,
},
};
static struct platform_device kirkwood_cpuidle = {
.name = "kirkwood_cpuidle",
.id = -1,
.resource = kirkwood_cpuidle_resource,
.num_resources = 1,
};
void __init kirkwood_cpuidle_init(void)
{
platform_device_register(&kirkwood_cpuidle);
}
/*****************************************************************************
* Time handling
****************************************************************************/
void __init kirkwood_init_early(void)
{
orion_time_set_base(TIMER_VIRT_BASE);
mvebu_mbus_init("marvell,kirkwood-mbus",
BRIDGE_WINS_BASE, BRIDGE_WINS_SZ,
DDR_WINDOW_CPU_BASE, DDR_WINDOW_CPU_SZ);
}
int kirkwood_tclk;
static int __init kirkwood_find_tclk(void)
{
u32 dev, rev;
kirkwood_pcie_id(&dev, &rev);
if (dev == MV88F6281_DEV_ID || dev == MV88F6282_DEV_ID)
if (((readl(SAMPLE_AT_RESET) >> 21) & 1) == 0)
return 200000000;
return 166666667;
}
void __init kirkwood_timer_init(void)
{
kirkwood_tclk = kirkwood_find_tclk();
orion_time_init(BRIDGE_VIRT_BASE, BRIDGE_INT_TIMER1_CLR,
IRQ_KIRKWOOD_BRIDGE, kirkwood_tclk);
}
/*****************************************************************************
* Audio
****************************************************************************/
static struct resource kirkwood_i2s_resources[] = {
[0] = {
.start = AUDIO_PHYS_BASE,
.end = AUDIO_PHYS_BASE + SZ_16K - 1,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_KIRKWOOD_I2S,
.end = IRQ_KIRKWOOD_I2S,
.flags = IORESOURCE_IRQ,
},
};
static struct kirkwood_asoc_platform_data kirkwood_i2s_data = {
.burst = 128,
};
static struct platform_device kirkwood_i2s_device = {
.name = "kirkwood-i2s",
.id = -1,
.num_resources = ARRAY_SIZE(kirkwood_i2s_resources),
.resource = kirkwood_i2s_resources,
.dev = {
.platform_data = &kirkwood_i2s_data,
},
};
static struct platform_device kirkwood_pcm_device = {
.name = "kirkwood-pcm-audio",
.id = -1,
};
void __init kirkwood_audio_init(void)
{
platform_device_register(&kirkwood_i2s_device);
platform_device_register(&kirkwood_pcm_device);
}
/*****************************************************************************
* General
****************************************************************************/
/*
* Identify device ID and revision.
*/
char * __init kirkwood_id(void)
{
u32 dev, rev;
kirkwood_pcie_id(&dev, &rev);
if (dev == MV88F6281_DEV_ID) {
if (rev == MV88F6281_REV_Z0)
return "MV88F6281-Z0";
else if (rev == MV88F6281_REV_A0)
return "MV88F6281-A0";
else if (rev == MV88F6281_REV_A1)
return "MV88F6281-A1";
else
return "MV88F6281-Rev-Unsupported";
} else if (dev == MV88F6192_DEV_ID) {
if (rev == MV88F6192_REV_Z0)
return "MV88F6192-Z0";
else if (rev == MV88F6192_REV_A0)
return "MV88F6192-A0";
else if (rev == MV88F6192_REV_A1)
return "MV88F6192-A1";
else
return "MV88F6192-Rev-Unsupported";
} else if (dev == MV88F6180_DEV_ID) {
if (rev == MV88F6180_REV_A0)
return "MV88F6180-Rev-A0";
else if (rev == MV88F6180_REV_A1)
return "MV88F6180-Rev-A1";
else
return "MV88F6180-Rev-Unsupported";
} else if (dev == MV88F6282_DEV_ID) {
if (rev == MV88F6282_REV_A0)
return "MV88F6282-Rev-A0";
else if (rev == MV88F6282_REV_A1)
return "MV88F6282-Rev-A1";
else
return "MV88F6282-Rev-Unsupported";
} else {
return "Device-Unknown";
}
}
void __init kirkwood_setup_wins(void)
{
/*
* The PCIe windows will no longer be statically allocated
* here once Kirkwood is migrated to the pci-mvebu driver.
*/
mvebu_mbus_add_window_remap_flags("pcie0.0",
KIRKWOOD_PCIE_IO_PHYS_BASE,
KIRKWOOD_PCIE_IO_SIZE,
KIRKWOOD_PCIE_IO_BUS_BASE,
MVEBU_MBUS_PCI_IO);
mvebu_mbus_add_window_remap_flags("pcie0.0",
KIRKWOOD_PCIE_MEM_PHYS_BASE,
KIRKWOOD_PCIE_MEM_SIZE,
MVEBU_MBUS_NO_REMAP,
MVEBU_MBUS_PCI_MEM);
mvebu_mbus_add_window_remap_flags("pcie1.0",
KIRKWOOD_PCIE1_IO_PHYS_BASE,
KIRKWOOD_PCIE1_IO_SIZE,
KIRKWOOD_PCIE1_IO_BUS_BASE,
MVEBU_MBUS_PCI_IO);
mvebu_mbus_add_window_remap_flags("pcie1.0",
KIRKWOOD_PCIE1_MEM_PHYS_BASE,
KIRKWOOD_PCIE1_MEM_SIZE,
MVEBU_MBUS_NO_REMAP,
MVEBU_MBUS_PCI_MEM);
mvebu_mbus_add_window("nand", KIRKWOOD_NAND_MEM_PHYS_BASE,
KIRKWOOD_NAND_MEM_SIZE);
mvebu_mbus_add_window("sram", KIRKWOOD_SRAM_PHYS_BASE,
KIRKWOOD_SRAM_SIZE);
}
void __init kirkwood_l2_init(void)
{
#ifdef CONFIG_CACHE_FEROCEON_L2
#ifdef CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH
writel(readl(L2_CONFIG_REG) | L2_WRITETHROUGH, L2_CONFIG_REG);
feroceon_l2_init(1);
#else
writel(readl(L2_CONFIG_REG) & ~L2_WRITETHROUGH, L2_CONFIG_REG);
feroceon_l2_init(0);
#endif
#endif
}
void __init kirkwood_init(void)
{
pr_info("Kirkwood: %s, TCLK=%d.\n", kirkwood_id(), kirkwood_tclk);
/*
* Disable propagation of mbus errors to the CPU local bus,
* as this causes mbus errors (which can occur for example
* for PCI aborts) to throw CPU aborts, which we're not set
* up to deal with.
*/
writel(readl(CPU_CONFIG) & ~CPU_CONFIG_ERROR_PROP, CPU_CONFIG);
kirkwood_setup_wins();
kirkwood_l2_init();
/* Setup root of clk tree */
kirkwood_clk_init();
/* internal devices that every board has */
kirkwood_rtc_init();
kirkwood_wdt_init();
kirkwood_xor0_init();
kirkwood_xor1_init();
kirkwood_crypto_init();
kirkwood_cpuidle_init();
#ifdef CONFIG_KEXEC
kexec_reinit = kirkwood_enable_pcie;
#endif
}
void kirkwood_restart(char mode, const char *cmd)
{
/*
* Enable soft reset to assert RSTOUTn.
*/
writel(SOFT_RESET_OUT_EN, RSTOUTn_MASK);
/*
* Assert soft reset.
*/
writel(SOFT_RESET, SYSTEM_SOFT_RESET);
while (1)
;
}