475 lines
10 KiB
C
475 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* drivers/clk/at91/sckc.c
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*
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* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
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*/
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#include <linux/clk-provider.h>
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#include <linux/clkdev.h>
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#include <linux/delay.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/io.h>
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#define SLOW_CLOCK_FREQ 32768
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#define SLOWCK_SW_CYCLES 5
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#define SLOWCK_SW_TIME_USEC ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
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SLOW_CLOCK_FREQ)
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#define AT91_SCKC_CR 0x00
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#define AT91_SCKC_RCEN (1 << 0)
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#define AT91_SCKC_OSC32EN (1 << 1)
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#define AT91_SCKC_OSC32BYP (1 << 2)
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#define AT91_SCKC_OSCSEL (1 << 3)
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struct clk_slow_osc {
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struct clk_hw hw;
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void __iomem *sckcr;
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unsigned long startup_usec;
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};
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#define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
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struct clk_sama5d4_slow_osc {
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struct clk_hw hw;
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void __iomem *sckcr;
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unsigned long startup_usec;
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bool prepared;
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};
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#define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)
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struct clk_slow_rc_osc {
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struct clk_hw hw;
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void __iomem *sckcr;
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unsigned long frequency;
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unsigned long accuracy;
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unsigned long startup_usec;
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};
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#define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
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struct clk_sam9x5_slow {
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struct clk_hw hw;
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void __iomem *sckcr;
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u8 parent;
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};
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#define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
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static int clk_slow_osc_prepare(struct clk_hw *hw)
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{
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struct clk_slow_osc *osc = to_clk_slow_osc(hw);
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void __iomem *sckcr = osc->sckcr;
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u32 tmp = readl(sckcr);
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if (tmp & (AT91_SCKC_OSC32BYP | AT91_SCKC_OSC32EN))
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return 0;
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writel(tmp | AT91_SCKC_OSC32EN, sckcr);
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usleep_range(osc->startup_usec, osc->startup_usec + 1);
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return 0;
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}
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static void clk_slow_osc_unprepare(struct clk_hw *hw)
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{
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struct clk_slow_osc *osc = to_clk_slow_osc(hw);
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void __iomem *sckcr = osc->sckcr;
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u32 tmp = readl(sckcr);
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if (tmp & AT91_SCKC_OSC32BYP)
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return;
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writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
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}
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static int clk_slow_osc_is_prepared(struct clk_hw *hw)
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{
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struct clk_slow_osc *osc = to_clk_slow_osc(hw);
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void __iomem *sckcr = osc->sckcr;
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u32 tmp = readl(sckcr);
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if (tmp & AT91_SCKC_OSC32BYP)
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return 1;
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return !!(tmp & AT91_SCKC_OSC32EN);
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}
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static const struct clk_ops slow_osc_ops = {
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.prepare = clk_slow_osc_prepare,
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.unprepare = clk_slow_osc_unprepare,
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.is_prepared = clk_slow_osc_is_prepared,
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};
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static struct clk_hw * __init
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at91_clk_register_slow_osc(void __iomem *sckcr,
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const char *name,
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const char *parent_name,
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unsigned long startup,
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bool bypass)
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{
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struct clk_slow_osc *osc;
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struct clk_hw *hw;
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struct clk_init_data init;
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int ret;
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if (!sckcr || !name || !parent_name)
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return ERR_PTR(-EINVAL);
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osc = kzalloc(sizeof(*osc), GFP_KERNEL);
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if (!osc)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &slow_osc_ops;
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init.parent_names = &parent_name;
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init.num_parents = 1;
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init.flags = CLK_IGNORE_UNUSED;
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osc->hw.init = &init;
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osc->sckcr = sckcr;
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osc->startup_usec = startup;
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if (bypass)
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writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
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sckcr);
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hw = &osc->hw;
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ret = clk_hw_register(NULL, &osc->hw);
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if (ret) {
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kfree(osc);
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hw = ERR_PTR(ret);
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}
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return hw;
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}
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static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
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return osc->frequency;
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}
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static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
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unsigned long parent_acc)
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{
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struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
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return osc->accuracy;
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}
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static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
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{
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struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
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void __iomem *sckcr = osc->sckcr;
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writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
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usleep_range(osc->startup_usec, osc->startup_usec + 1);
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return 0;
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}
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static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
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{
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struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
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void __iomem *sckcr = osc->sckcr;
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writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
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}
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static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
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{
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struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
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return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
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}
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static const struct clk_ops slow_rc_osc_ops = {
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.prepare = clk_slow_rc_osc_prepare,
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.unprepare = clk_slow_rc_osc_unprepare,
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.is_prepared = clk_slow_rc_osc_is_prepared,
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.recalc_rate = clk_slow_rc_osc_recalc_rate,
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.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
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};
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static struct clk_hw * __init
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at91_clk_register_slow_rc_osc(void __iomem *sckcr,
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const char *name,
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unsigned long frequency,
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unsigned long accuracy,
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unsigned long startup)
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{
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struct clk_slow_rc_osc *osc;
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struct clk_hw *hw;
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struct clk_init_data init;
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int ret;
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if (!sckcr || !name)
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return ERR_PTR(-EINVAL);
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osc = kzalloc(sizeof(*osc), GFP_KERNEL);
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if (!osc)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &slow_rc_osc_ops;
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init.parent_names = NULL;
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init.num_parents = 0;
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init.flags = CLK_IGNORE_UNUSED;
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osc->hw.init = &init;
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osc->sckcr = sckcr;
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osc->frequency = frequency;
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osc->accuracy = accuracy;
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osc->startup_usec = startup;
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hw = &osc->hw;
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ret = clk_hw_register(NULL, &osc->hw);
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if (ret) {
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kfree(osc);
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hw = ERR_PTR(ret);
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}
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return hw;
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}
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static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
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{
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struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
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void __iomem *sckcr = slowck->sckcr;
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u32 tmp;
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if (index > 1)
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return -EINVAL;
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tmp = readl(sckcr);
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if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
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(index && (tmp & AT91_SCKC_OSCSEL)))
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return 0;
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if (index)
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tmp |= AT91_SCKC_OSCSEL;
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else
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tmp &= ~AT91_SCKC_OSCSEL;
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writel(tmp, sckcr);
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usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
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return 0;
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}
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static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
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{
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struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
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return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
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}
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static const struct clk_ops sam9x5_slow_ops = {
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.set_parent = clk_sam9x5_slow_set_parent,
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.get_parent = clk_sam9x5_slow_get_parent,
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};
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static struct clk_hw * __init
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at91_clk_register_sam9x5_slow(void __iomem *sckcr,
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const char *name,
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const char **parent_names,
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int num_parents)
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{
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struct clk_sam9x5_slow *slowck;
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struct clk_hw *hw;
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struct clk_init_data init;
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int ret;
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if (!sckcr || !name || !parent_names || !num_parents)
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return ERR_PTR(-EINVAL);
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slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
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if (!slowck)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &sam9x5_slow_ops;
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init.parent_names = parent_names;
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init.num_parents = num_parents;
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init.flags = 0;
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slowck->hw.init = &init;
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slowck->sckcr = sckcr;
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slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
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hw = &slowck->hw;
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ret = clk_hw_register(NULL, &slowck->hw);
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if (ret) {
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kfree(slowck);
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hw = ERR_PTR(ret);
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}
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return hw;
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}
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static void __init at91sam9x5_sckc_register(struct device_node *np,
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unsigned int rc_osc_startup_us)
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{
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const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
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void __iomem *regbase = of_iomap(np, 0);
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struct device_node *child = NULL;
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const char *xtal_name;
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struct clk_hw *hw;
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bool bypass;
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if (!regbase)
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return;
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hw = at91_clk_register_slow_rc_osc(regbase, parent_names[0], 32768,
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50000000, rc_osc_startup_us);
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if (IS_ERR(hw))
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return;
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xtal_name = of_clk_get_parent_name(np, 0);
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if (!xtal_name) {
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/* DT backward compatibility */
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child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow-osc");
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if (!child)
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return;
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xtal_name = of_clk_get_parent_name(child, 0);
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bypass = of_property_read_bool(child, "atmel,osc-bypass");
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child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow");
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} else {
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bypass = of_property_read_bool(np, "atmel,osc-bypass");
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}
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if (!xtal_name)
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return;
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hw = at91_clk_register_slow_osc(regbase, parent_names[1], xtal_name,
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1200000, bypass);
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if (IS_ERR(hw))
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return;
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hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
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if (IS_ERR(hw))
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return;
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of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
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/* DT backward compatibility */
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if (child)
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of_clk_add_hw_provider(child, of_clk_hw_simple_get, hw);
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}
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static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
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{
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at91sam9x5_sckc_register(np, 75);
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}
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CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
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of_at91sam9x5_sckc_setup);
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static void __init of_sama5d3_sckc_setup(struct device_node *np)
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{
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at91sam9x5_sckc_register(np, 500);
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}
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CLK_OF_DECLARE(sama5d3_clk_sckc, "atmel,sama5d3-sckc",
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of_sama5d3_sckc_setup);
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static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
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{
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struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
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if (osc->prepared)
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return 0;
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/*
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* Assume that if it has already been selected (for example by the
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* bootloader), enough time has aready passed.
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*/
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if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) {
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osc->prepared = true;
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return 0;
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}
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usleep_range(osc->startup_usec, osc->startup_usec + 1);
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osc->prepared = true;
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return 0;
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}
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static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
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{
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struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
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return osc->prepared;
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}
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static const struct clk_ops sama5d4_slow_osc_ops = {
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.prepare = clk_sama5d4_slow_osc_prepare,
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.is_prepared = clk_sama5d4_slow_osc_is_prepared,
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};
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static void __init of_sama5d4_sckc_setup(struct device_node *np)
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{
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void __iomem *regbase = of_iomap(np, 0);
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struct clk_hw *hw;
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struct clk_sama5d4_slow_osc *osc;
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struct clk_init_data init;
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const char *xtal_name;
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const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
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bool bypass;
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int ret;
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if (!regbase)
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return;
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hw = clk_hw_register_fixed_rate_with_accuracy(NULL, parent_names[0],
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NULL, 0, 32768,
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250000000);
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if (IS_ERR(hw))
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return;
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xtal_name = of_clk_get_parent_name(np, 0);
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bypass = of_property_read_bool(np, "atmel,osc-bypass");
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osc = kzalloc(sizeof(*osc), GFP_KERNEL);
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if (!osc)
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return;
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init.name = parent_names[1];
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init.ops = &sama5d4_slow_osc_ops;
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init.parent_names = &xtal_name;
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init.num_parents = 1;
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init.flags = CLK_IGNORE_UNUSED;
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osc->hw.init = &init;
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osc->sckcr = regbase;
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osc->startup_usec = 1200000;
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if (bypass)
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writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase);
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hw = &osc->hw;
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ret = clk_hw_register(NULL, &osc->hw);
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if (ret) {
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kfree(osc);
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return;
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}
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hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
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if (IS_ERR(hw))
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return;
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of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
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}
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CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
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of_sama5d4_sckc_setup);
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