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![Wenyou Yang](/assets/img/avatar_default.png)
As said in the SAMA5D2 datasheet, the PLLA clock must be divided by 2 by writing the PLLADIV2 bit in PMC_MCKR, if the ratio between PCK and MCK is 3 (MDIV = 3). This is the purpose of the driver. Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
89 lines
1.9 KiB
C
89 lines
1.9 KiB
C
/*
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* Copyright (C) 2018 Microhip / Atmel Corporation
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* Wenyou.Yang <wenyou.yang@microchip.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <clk-uclass.h>
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#include <dm/device.h>
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#include <linux/io.h>
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#include <mach/at91_pmc.h>
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#include "pmc.h"
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DECLARE_GLOBAL_DATA_PTR;
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static int at91_plladiv_clk_enable(struct clk *clk)
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{
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return 0;
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}
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static ulong at91_plladiv_clk_get_rate(struct clk *clk)
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{
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struct pmc_platdata *plat = dev_get_platdata(clk->dev);
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struct at91_pmc *pmc = plat->reg_base;
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struct clk source;
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ulong clk_rate;
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int ret;
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ret = clk_get_by_index(clk->dev, 0, &source);
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if (ret)
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return -EINVAL;
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clk_rate = clk_get_rate(&source);
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if (readl(&pmc->mckr) & AT91_PMC_MCKR_PLLADIV_2)
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clk_rate /= 2;
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return clk_rate;
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}
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static ulong at91_plladiv_clk_set_rate(struct clk *clk, ulong rate)
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{
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struct pmc_platdata *plat = dev_get_platdata(clk->dev);
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struct at91_pmc *pmc = plat->reg_base;
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struct clk source;
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ulong parent_rate;
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int ret;
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ret = clk_get_by_index(clk->dev, 0, &source);
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if (ret)
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return -EINVAL;
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parent_rate = clk_get_rate(&source);
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if ((parent_rate != rate) && ((parent_rate) / 2 != rate))
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return -EINVAL;
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if (parent_rate != rate) {
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writel((readl(&pmc->mckr) | AT91_PMC_MCKR_PLLADIV_2),
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&pmc->mckr);
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}
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return 0;
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}
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static struct clk_ops at91_plladiv_clk_ops = {
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.enable = at91_plladiv_clk_enable,
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.get_rate = at91_plladiv_clk_get_rate,
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.set_rate = at91_plladiv_clk_set_rate,
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};
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static int at91_plladiv_clk_probe(struct udevice *dev)
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{
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return at91_pmc_core_probe(dev);
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}
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static const struct udevice_id at91_plladiv_clk_match[] = {
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{ .compatible = "atmel,at91sam9x5-clk-plldiv" },
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{}
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};
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U_BOOT_DRIVER(at91_plladiv_clk) = {
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.name = "at91-plladiv-clk",
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.id = UCLASS_CLK,
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.of_match = at91_plladiv_clk_match,
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.probe = at91_plladiv_clk_probe,
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.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
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.ops = &at91_plladiv_clk_ops,
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};
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