410 строки
11 KiB
C
410 строки
11 KiB
C
/*
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* arch/arm/mach-ep93xx/clock.c
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* Clock control for Cirrus EP93xx chips.
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*
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* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/io.h>
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#include <asm/clkdev.h>
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#include <asm/div64.h>
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#include <mach/hardware.h>
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struct clk {
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unsigned long rate;
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int users;
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int sw_locked;
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void __iomem *enable_reg;
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u32 enable_mask;
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unsigned long (*get_rate)(struct clk *clk);
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int (*set_rate)(struct clk *clk, unsigned long rate);
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};
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static unsigned long get_uart_rate(struct clk *clk);
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static int set_keytchclk_rate(struct clk *clk, unsigned long rate);
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static int set_div_rate(struct clk *clk, unsigned long rate);
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static struct clk clk_uart1 = {
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.sw_locked = 1,
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.enable_reg = EP93XX_SYSCON_DEVCFG,
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.enable_mask = EP93XX_SYSCON_DEVCFG_U1EN,
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.get_rate = get_uart_rate,
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};
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static struct clk clk_uart2 = {
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.sw_locked = 1,
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.enable_reg = EP93XX_SYSCON_DEVCFG,
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.enable_mask = EP93XX_SYSCON_DEVCFG_U2EN,
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.get_rate = get_uart_rate,
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};
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static struct clk clk_uart3 = {
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.sw_locked = 1,
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.enable_reg = EP93XX_SYSCON_DEVCFG,
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.enable_mask = EP93XX_SYSCON_DEVCFG_U3EN,
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.get_rate = get_uart_rate,
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};
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static struct clk clk_pll1;
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static struct clk clk_f;
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static struct clk clk_h;
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static struct clk clk_p;
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static struct clk clk_pll2;
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static struct clk clk_usb_host = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN,
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};
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static struct clk clk_keypad = {
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.sw_locked = 1,
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.enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV,
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.enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
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.set_rate = set_keytchclk_rate,
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};
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static struct clk clk_pwm = {
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.rate = EP93XX_EXT_CLK_RATE,
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};
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static struct clk clk_video = {
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.sw_locked = 1,
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.enable_reg = EP93XX_SYSCON_VIDCLKDIV,
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.enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
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.set_rate = set_div_rate,
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};
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/* DMA Clocks */
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static struct clk clk_m2p0 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P0,
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};
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static struct clk clk_m2p1 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P1,
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};
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static struct clk clk_m2p2 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P2,
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};
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static struct clk clk_m2p3 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P3,
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};
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static struct clk clk_m2p4 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P4,
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};
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static struct clk clk_m2p5 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P5,
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};
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static struct clk clk_m2p6 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P6,
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};
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static struct clk clk_m2p7 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P7,
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};
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static struct clk clk_m2p8 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P8,
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};
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static struct clk clk_m2p9 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P9,
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};
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static struct clk clk_m2m0 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M0,
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};
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static struct clk clk_m2m1 = {
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.enable_reg = EP93XX_SYSCON_PWRCNT,
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.enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M1,
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};
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#define INIT_CK(dev,con,ck) \
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{ .dev_id = dev, .con_id = con, .clk = ck }
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static struct clk_lookup clocks[] = {
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INIT_CK("apb:uart1", NULL, &clk_uart1),
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INIT_CK("apb:uart2", NULL, &clk_uart2),
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INIT_CK("apb:uart3", NULL, &clk_uart3),
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INIT_CK(NULL, "pll1", &clk_pll1),
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INIT_CK(NULL, "fclk", &clk_f),
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INIT_CK(NULL, "hclk", &clk_h),
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INIT_CK(NULL, "pclk", &clk_p),
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INIT_CK(NULL, "pll2", &clk_pll2),
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INIT_CK("ep93xx-ohci", NULL, &clk_usb_host),
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INIT_CK("ep93xx-keypad", NULL, &clk_keypad),
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INIT_CK("ep93xx-fb", NULL, &clk_video),
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INIT_CK(NULL, "pwm_clk", &clk_pwm),
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INIT_CK(NULL, "m2p0", &clk_m2p0),
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INIT_CK(NULL, "m2p1", &clk_m2p1),
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INIT_CK(NULL, "m2p2", &clk_m2p2),
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INIT_CK(NULL, "m2p3", &clk_m2p3),
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INIT_CK(NULL, "m2p4", &clk_m2p4),
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INIT_CK(NULL, "m2p5", &clk_m2p5),
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INIT_CK(NULL, "m2p6", &clk_m2p6),
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INIT_CK(NULL, "m2p7", &clk_m2p7),
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INIT_CK(NULL, "m2p8", &clk_m2p8),
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INIT_CK(NULL, "m2p9", &clk_m2p9),
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INIT_CK(NULL, "m2m0", &clk_m2m0),
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INIT_CK(NULL, "m2m1", &clk_m2m1),
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};
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int clk_enable(struct clk *clk)
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{
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if (!clk->users++ && clk->enable_reg) {
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u32 value;
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value = __raw_readl(clk->enable_reg);
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value |= clk->enable_mask;
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if (clk->sw_locked)
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ep93xx_syscon_swlocked_write(value, clk->enable_reg);
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else
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__raw_writel(value, clk->enable_reg);
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}
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return 0;
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}
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EXPORT_SYMBOL(clk_enable);
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void clk_disable(struct clk *clk)
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{
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if (!--clk->users && clk->enable_reg) {
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u32 value;
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value = __raw_readl(clk->enable_reg);
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value &= ~clk->enable_mask;
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if (clk->sw_locked)
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ep93xx_syscon_swlocked_write(value, clk->enable_reg);
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else
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__raw_writel(value, clk->enable_reg);
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}
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}
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EXPORT_SYMBOL(clk_disable);
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static unsigned long get_uart_rate(struct clk *clk)
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{
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u32 value;
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value = __raw_readl(EP93XX_SYSCON_PWRCNT);
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if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD)
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return EP93XX_EXT_CLK_RATE;
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else
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return EP93XX_EXT_CLK_RATE / 2;
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}
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unsigned long clk_get_rate(struct clk *clk)
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{
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if (clk->get_rate)
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return clk->get_rate(clk);
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return clk->rate;
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}
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EXPORT_SYMBOL(clk_get_rate);
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static int set_keytchclk_rate(struct clk *clk, unsigned long rate)
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{
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u32 val;
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u32 div_bit;
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val = __raw_readl(clk->enable_reg);
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/*
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* The Key Matrix and ADC clocks are configured using the same
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* System Controller register. The clock used will be either
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* 1/4 or 1/16 the external clock rate depending on the
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* EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV
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* bit being set or cleared.
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*/
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div_bit = clk->enable_mask >> 15;
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if (rate == EP93XX_KEYTCHCLK_DIV4)
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val |= div_bit;
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else if (rate == EP93XX_KEYTCHCLK_DIV16)
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val &= ~div_bit;
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else
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return -EINVAL;
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ep93xx_syscon_swlocked_write(val, clk->enable_reg);
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clk->rate = rate;
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return 0;
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}
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static unsigned long calc_clk_div(unsigned long rate, int *psel, int *esel,
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int *pdiv, int *div)
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{
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unsigned long max_rate, best_rate = 0,
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actual_rate = 0, mclk_rate = 0, rate_err = -1;
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int i, found = 0, __div = 0, __pdiv = 0;
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/* Don't exceed the maximum rate */
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max_rate = max(max(clk_pll1.rate / 4, clk_pll2.rate / 4),
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(unsigned long)EP93XX_EXT_CLK_RATE / 4);
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rate = min(rate, max_rate);
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/*
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* Try the two pll's and the external clock
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* Because the valid predividers are 2, 2.5 and 3, we multiply
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* all the clocks by 2 to avoid floating point math.
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*
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* This is based on the algorithm in the ep93xx raster guide:
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* http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
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*
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*/
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for (i = 0; i < 3; i++) {
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if (i == 0)
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mclk_rate = EP93XX_EXT_CLK_RATE * 2;
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else if (i == 1)
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mclk_rate = clk_pll1.rate * 2;
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else if (i == 2)
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mclk_rate = clk_pll2.rate * 2;
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/* Try each predivider value */
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for (__pdiv = 4; __pdiv <= 6; __pdiv++) {
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__div = mclk_rate / (rate * __pdiv);
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if (__div < 2 || __div > 127)
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continue;
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actual_rate = mclk_rate / (__pdiv * __div);
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if (!found || abs(actual_rate - rate) < rate_err) {
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*pdiv = __pdiv - 3;
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*div = __div;
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*psel = (i == 2);
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*esel = (i != 0);
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best_rate = actual_rate;
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rate_err = abs(actual_rate - rate);
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found = 1;
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}
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}
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}
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if (!found)
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return 0;
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return best_rate;
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}
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static int set_div_rate(struct clk *clk, unsigned long rate)
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{
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unsigned long actual_rate;
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int psel = 0, esel = 0, pdiv = 0, div = 0;
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u32 val;
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actual_rate = calc_clk_div(rate, &psel, &esel, &pdiv, &div);
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if (actual_rate == 0)
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return -EINVAL;
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clk->rate = actual_rate;
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/* Clear the esel, psel, pdiv and div bits */
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val = __raw_readl(clk->enable_reg);
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val &= ~0x7fff;
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/* Set the new esel, psel, pdiv and div bits for the new clock rate */
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val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) |
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(psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) |
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(pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div;
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ep93xx_syscon_swlocked_write(val, clk->enable_reg);
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return 0;
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}
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int clk_set_rate(struct clk *clk, unsigned long rate)
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{
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if (clk->set_rate)
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return clk->set_rate(clk, rate);
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return -EINVAL;
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}
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EXPORT_SYMBOL(clk_set_rate);
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static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
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static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
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static char pclk_divisors[] = { 1, 2, 4, 8 };
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/*
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* PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
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*/
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static unsigned long calc_pll_rate(u32 config_word)
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{
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unsigned long long rate;
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int i;
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rate = EP93XX_EXT_CLK_RATE;
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rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */
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rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */
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do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */
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for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */
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rate >>= 1;
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return (unsigned long)rate;
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}
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static void __init ep93xx_dma_clock_init(void)
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{
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clk_m2p0.rate = clk_h.rate;
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clk_m2p1.rate = clk_h.rate;
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clk_m2p2.rate = clk_h.rate;
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clk_m2p3.rate = clk_h.rate;
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clk_m2p4.rate = clk_h.rate;
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clk_m2p5.rate = clk_h.rate;
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clk_m2p6.rate = clk_h.rate;
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clk_m2p7.rate = clk_h.rate;
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clk_m2p8.rate = clk_h.rate;
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clk_m2p9.rate = clk_h.rate;
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clk_m2m0.rate = clk_h.rate;
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clk_m2m1.rate = clk_h.rate;
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}
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static int __init ep93xx_clock_init(void)
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{
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u32 value;
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int i;
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value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1);
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if (!(value & 0x00800000)) { /* PLL1 bypassed? */
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clk_pll1.rate = EP93XX_EXT_CLK_RATE;
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} else {
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clk_pll1.rate = calc_pll_rate(value);
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}
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clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
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clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
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clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
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ep93xx_dma_clock_init();
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value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2);
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if (!(value & 0x00080000)) { /* PLL2 bypassed? */
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clk_pll2.rate = EP93XX_EXT_CLK_RATE;
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} else if (value & 0x00040000) { /* PLL2 enabled? */
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clk_pll2.rate = calc_pll_rate(value);
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} else {
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clk_pll2.rate = 0;
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}
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clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
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printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
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clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
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printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
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clk_f.rate / 1000000, clk_h.rate / 1000000,
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clk_p.rate / 1000000);
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for (i = 0; i < ARRAY_SIZE(clocks); i++)
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clkdev_add(&clocks[i]);
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return 0;
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}
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arch_initcall(ep93xx_clock_init);
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