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https://github.com/brain-hackers/u-boot-brain
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e7c831543a
By default, it is assumed that the UTMI clock is generated from a 12 MHz reference clock (MAINCK). If it's not the case, the FREQ field of the SFR_UTMICKTRIM has to be updated to generate the UTMI clock in the proper way. The UTMI clock has a fixed rate of 480 MHz. In fact, there is no multiplier we can configure. The multiplier is managed internally, depending on the reference clock frequency, to achieve the target of 480 MHz. The patch is cloned from the patch of mailing-list: [PATCH v2] clk: at91: utmi: set the mainck rate Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com> [trini: Depend on SPL_DM] Signed-off-by: Tom Rini <trini@konsulko.com>
141 lines
2.9 KiB
C
141 lines
2.9 KiB
C
/*
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* Copyright (C) 2016 Atmel Corporation
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* Wenyou.Yang <wenyou.yang@atmel.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.h>
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#include <syscon.h>
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#include <linux/io.h>
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#include <mach/at91_pmc.h>
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#include <mach/sama5_sfr.h>
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#include "pmc.h"
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DECLARE_GLOBAL_DATA_PTR;
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/*
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* The purpose of this clock is to generate a 480 MHz signal. A different
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* rate can't be configured.
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*/
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#define UTMI_RATE 480000000
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static int utmi_clk_enable(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 clk_dev;
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ulong clk_rate;
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u32 utmi_ref_clk_freq;
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u32 tmp;
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int err;
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if (readl(&pmc->sr) & AT91_PMC_LOCKU)
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return 0;
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/*
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* If mainck rate is different from 12 MHz, we have to configure the
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* FREQ field of the SFR_UTMICKTRIM register to generate properly
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* the utmi clock.
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*/
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err = clk_get_by_index(clk->dev, 0, &clk_dev);
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if (err)
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return -EINVAL;
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clk_rate = clk_get_rate(&clk_dev);
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switch (clk_rate) {
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case 12000000:
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utmi_ref_clk_freq = 0;
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break;
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case 16000000:
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utmi_ref_clk_freq = 1;
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break;
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case 24000000:
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utmi_ref_clk_freq = 2;
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break;
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/*
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* Not supported on SAMA5D2 but it's not an issue since MAINCK
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* maximum value is 24 MHz.
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*/
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case 48000000:
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utmi_ref_clk_freq = 3;
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break;
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default:
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printf("UTMICK: unsupported mainck rate\n");
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return -EINVAL;
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}
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if (plat->regmap_sfr) {
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err = regmap_read(plat->regmap_sfr, AT91_SFR_UTMICKTRIM, &tmp);
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if (err)
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return -EINVAL;
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tmp &= ~AT91_UTMICKTRIM_FREQ;
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tmp |= utmi_ref_clk_freq;
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err = regmap_write(plat->regmap_sfr, AT91_SFR_UTMICKTRIM, tmp);
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if (err)
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return -EINVAL;
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} else if (utmi_ref_clk_freq) {
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printf("UTMICK: sfr node required\n");
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return -EINVAL;
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}
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tmp = readl(&pmc->uckr);
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tmp |= AT91_PMC_UPLLEN |
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AT91_PMC_UPLLCOUNT |
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AT91_PMC_BIASEN;
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writel(tmp, &pmc->uckr);
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while (!(readl(&pmc->sr) & AT91_PMC_LOCKU))
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;
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return 0;
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}
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static ulong utmi_clk_get_rate(struct clk *clk)
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{
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/* UTMI clk rate is fixed. */
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return UTMI_RATE;
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}
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static struct clk_ops utmi_clk_ops = {
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.enable = utmi_clk_enable,
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.get_rate = utmi_clk_get_rate,
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};
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static int utmi_clk_ofdata_to_platdata(struct udevice *dev)
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{
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struct pmc_platdata *plat = dev_get_platdata(dev);
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struct udevice *syscon;
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uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
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"regmap-sfr", &syscon);
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if (syscon)
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plat->regmap_sfr = syscon_get_regmap(syscon);
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return 0;
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}
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static int utmi_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 utmi_clk_match[] = {
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{ .compatible = "atmel,at91sam9x5-clk-utmi" },
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{}
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};
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U_BOOT_DRIVER(at91sam9x5_utmi_clk) = {
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.name = "at91sam9x5-utmi-clk",
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.id = UCLASS_CLK,
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.of_match = utmi_clk_match,
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.probe = utmi_clk_probe,
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.ofdata_to_platdata = utmi_clk_ofdata_to_platdata,
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.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
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.ops = &utmi_clk_ops,
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};
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