mirror of
https://github.com/AsahiLinux/u-boot
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e9cd3d7024
In case the slow clock is not properly configured, the UTMI clock cannot lock the PLL, because UPLLCOUNT will "wait X slow clock cycles". In this case U-boot will loop indefinitely. Added a timeout in this case, to start U-boot even if UTMI clock is not enabled, so the user can use different media if needed, or investigate. Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
142 lines
3 KiB
C
142 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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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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#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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/*
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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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int timeout = 2000000;
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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 ((--timeout) && !(readl(&pmc->sr) & AT91_PMC_LOCKU))
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;
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if (!timeout) {
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printf("UTMICK: timeout waiting for UPLL lock\n");
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return -ETIMEDOUT;
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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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