![Matthias Wieloch](/assets/img/avatar_default.png)
The prescaler formula of the programmable clock has changed for sama5d2.
Update the driver accordingly.
Fixes: a2038077de
("clk: at91: add sama5d2 PMC driver")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[nicolas.ferre@microchip.com: adapt the prescaler range,
fix clk_programmable_recalc_rate, split patch]
Signed-off-by: Matthias Wieloch <matthias.wieloch@few-bauer.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
250 lines
5.8 KiB
C
250 lines
5.8 KiB
C
/*
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* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
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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
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* (at your option) any later version.
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*
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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/clk/at91_pmc.h>
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#include <linux/of.h>
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#include <linux/mfd/syscon.h>
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#include <linux/regmap.h>
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#include "pmc.h"
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#define PROG_ID_MAX 7
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#define PROG_STATUS_MASK(id) (1 << ((id) + 8))
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#define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & layout->pres_mask)
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#define PROG_MAX_RM9200_CSS 3
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struct clk_programmable {
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struct clk_hw hw;
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struct regmap *regmap;
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u8 id;
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const struct clk_programmable_layout *layout;
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};
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#define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw)
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static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct clk_programmable *prog = to_clk_programmable(hw);
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const struct clk_programmable_layout *layout = prog->layout;
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unsigned int pckr;
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unsigned long rate;
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regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
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if (layout->is_pres_direct)
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rate = parent_rate / (PROG_PRES(layout, pckr) + 1);
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else
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rate = parent_rate >> PROG_PRES(layout, pckr);
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return rate;
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}
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static int clk_programmable_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct clk_programmable *prog = to_clk_programmable(hw);
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const struct clk_programmable_layout *layout = prog->layout;
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struct clk_hw *parent;
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long best_rate = -EINVAL;
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unsigned long parent_rate;
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unsigned long tmp_rate = 0;
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int shift;
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int i;
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for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
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parent = clk_hw_get_parent_by_index(hw, i);
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if (!parent)
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continue;
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parent_rate = clk_hw_get_rate(parent);
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if (layout->is_pres_direct) {
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for (shift = 0; shift <= layout->pres_mask; shift++) {
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tmp_rate = parent_rate / (shift + 1);
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if (tmp_rate <= req->rate)
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break;
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}
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} else {
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for (shift = 0; shift < layout->pres_mask; shift++) {
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tmp_rate = parent_rate >> shift;
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if (tmp_rate <= req->rate)
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break;
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}
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}
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if (tmp_rate > req->rate)
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continue;
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if (best_rate < 0 ||
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(req->rate - tmp_rate) < (req->rate - best_rate)) {
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best_rate = tmp_rate;
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req->best_parent_rate = parent_rate;
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req->best_parent_hw = parent;
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}
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if (!best_rate)
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break;
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}
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if (best_rate < 0)
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return best_rate;
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req->rate = best_rate;
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return 0;
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}
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static int clk_programmable_set_parent(struct clk_hw *hw, u8 index)
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{
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struct clk_programmable *prog = to_clk_programmable(hw);
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const struct clk_programmable_layout *layout = prog->layout;
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unsigned int mask = layout->css_mask;
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unsigned int pckr = index;
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if (layout->have_slck_mck)
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mask |= AT91_PMC_CSSMCK_MCK;
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if (index > layout->css_mask) {
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if (index > PROG_MAX_RM9200_CSS && !layout->have_slck_mck)
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return -EINVAL;
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pckr |= AT91_PMC_CSSMCK_MCK;
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}
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regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id), mask, pckr);
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return 0;
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}
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static u8 clk_programmable_get_parent(struct clk_hw *hw)
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{
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struct clk_programmable *prog = to_clk_programmable(hw);
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const struct clk_programmable_layout *layout = prog->layout;
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unsigned int pckr;
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u8 ret;
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regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
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ret = pckr & layout->css_mask;
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if (layout->have_slck_mck && (pckr & AT91_PMC_CSSMCK_MCK) && !ret)
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ret = PROG_MAX_RM9200_CSS + 1;
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return ret;
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}
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static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct clk_programmable *prog = to_clk_programmable(hw);
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const struct clk_programmable_layout *layout = prog->layout;
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unsigned long div = parent_rate / rate;
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int shift = 0;
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if (!div)
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return -EINVAL;
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if (layout->is_pres_direct) {
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shift = div - 1;
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if (shift > layout->pres_mask)
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return -EINVAL;
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} else {
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shift = fls(div) - 1;
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if (div != (1 << shift))
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return -EINVAL;
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if (shift >= layout->pres_mask)
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return -EINVAL;
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}
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regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id),
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layout->pres_mask << layout->pres_shift,
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shift << layout->pres_shift);
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return 0;
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}
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static const struct clk_ops programmable_ops = {
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.recalc_rate = clk_programmable_recalc_rate,
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.determine_rate = clk_programmable_determine_rate,
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.get_parent = clk_programmable_get_parent,
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.set_parent = clk_programmable_set_parent,
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.set_rate = clk_programmable_set_rate,
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};
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struct clk_hw * __init
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at91_clk_register_programmable(struct regmap *regmap,
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const char *name, const char **parent_names,
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u8 num_parents, u8 id,
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const struct clk_programmable_layout *layout)
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{
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struct clk_programmable *prog;
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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 (id > PROG_ID_MAX)
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return ERR_PTR(-EINVAL);
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prog = kzalloc(sizeof(*prog), GFP_KERNEL);
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if (!prog)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &programmable_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 = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
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prog->id = id;
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prog->layout = layout;
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prog->hw.init = &init;
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prog->regmap = regmap;
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hw = &prog->hw;
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ret = clk_hw_register(NULL, &prog->hw);
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if (ret) {
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kfree(prog);
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hw = ERR_PTR(ret);
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} else {
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pmc_register_pck(id);
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}
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return hw;
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}
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const struct clk_programmable_layout at91rm9200_programmable_layout = {
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.pres_mask = 0x7,
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.pres_shift = 2,
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.css_mask = 0x3,
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.have_slck_mck = 0,
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.is_pres_direct = 0,
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};
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const struct clk_programmable_layout at91sam9g45_programmable_layout = {
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.pres_mask = 0x7,
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.pres_shift = 2,
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.css_mask = 0x3,
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.have_slck_mck = 1,
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.is_pres_direct = 0,
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};
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const struct clk_programmable_layout at91sam9x5_programmable_layout = {
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.pres_mask = 0x7,
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.pres_shift = 4,
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.css_mask = 0x7,
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.have_slck_mck = 0,
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.is_pres_direct = 0,
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};
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