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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * UTMI clock support for AT91 architectures.
- *
- * Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
- *
- * Author: Claudiu Beznea <claudiu.beznea@microchip.com>
- *
- * Based on drivers/clk/at91/clk-utmi.c from Linux.
- */
- #include <asm/processor.h>
- #include <common.h>
- #include <clk-uclass.h>
- #include <dm.h>
- #include <linux/clk-provider.h>
- #include <linux/clk/at91_pmc.h>
- #include <mach/at91_sfr.h>
- #include <regmap.h>
- #include <syscon.h>
- #include "pmc.h"
- #define UBOOT_DM_CLK_AT91_UTMI "at91-utmi-clk"
- #define UBOOT_DM_CLK_AT91_SAMA7G5_UTMI "at91-sama7g5-utmi-clk"
- /*
- * The purpose of this clock is to generate a 480 MHz signal. A different
- * rate can't be configured.
- */
- #define UTMI_RATE 480000000
- struct clk_utmi {
- void __iomem *base;
- struct regmap *regmap_sfr;
- struct clk clk;
- };
- #define to_clk_utmi(_clk) container_of(_clk, struct clk_utmi, clk)
- static inline bool clk_utmi_ready(struct regmap *regmap)
- {
- unsigned int status;
- pmc_read(regmap, AT91_PMC_SR, &status);
- return !!(status & AT91_PMC_LOCKU);
- }
- static int clk_utmi_enable(struct clk *clk)
- {
- struct clk_utmi *utmi = to_clk_utmi(clk);
- unsigned int uckr = AT91_PMC_UPLLEN | AT91_PMC_UPLLCOUNT |
- AT91_PMC_BIASEN;
- unsigned int utmi_ref_clk_freq;
- ulong parent_rate = clk_get_parent_rate(clk);
- /*
- * If mainck rate is different from 12 MHz, we have to configure the
- * FREQ field of the SFR_UTMICKTRIM register to generate properly
- * the utmi clock.
- */
- switch (parent_rate) {
- case 12000000:
- utmi_ref_clk_freq = 0;
- break;
- case 16000000:
- utmi_ref_clk_freq = 1;
- break;
- case 24000000:
- utmi_ref_clk_freq = 2;
- break;
- /*
- * Not supported on SAMA5D2 but it's not an issue since MAINCK
- * maximum value is 24 MHz.
- */
- case 48000000:
- utmi_ref_clk_freq = 3;
- break;
- default:
- debug("UTMICK: unsupported mainck rate\n");
- return -EINVAL;
- }
- if (utmi->regmap_sfr) {
- regmap_update_bits(utmi->regmap_sfr, AT91_SFR_UTMICKTRIM,
- AT91_UTMICKTRIM_FREQ, utmi_ref_clk_freq);
- } else if (utmi_ref_clk_freq) {
- debug("UTMICK: sfr node required\n");
- return -EINVAL;
- }
- pmc_update_bits(utmi->base, AT91_CKGR_UCKR, uckr, uckr);
- while (!clk_utmi_ready(utmi->base)) {
- debug("waiting for utmi...\n");
- cpu_relax();
- }
- return 0;
- }
- static int clk_utmi_disable(struct clk *clk)
- {
- struct clk_utmi *utmi = to_clk_utmi(clk);
- pmc_update_bits(utmi->base, AT91_CKGR_UCKR, AT91_PMC_UPLLEN, 0);
- return 0;
- }
- static ulong clk_utmi_get_rate(struct clk *clk)
- {
- /* UTMI clk rate is fixed. */
- return UTMI_RATE;
- }
- static const struct clk_ops utmi_ops = {
- .enable = clk_utmi_enable,
- .disable = clk_utmi_disable,
- .get_rate = clk_utmi_get_rate,
- };
- struct clk *at91_clk_register_utmi(void __iomem *base, struct udevice *dev,
- const char *name, const char *parent_name)
- {
- struct udevice *syscon;
- struct clk_utmi *utmi;
- struct clk *clk;
- int ret;
- if (!base || !dev || !name || !parent_name)
- return ERR_PTR(-EINVAL);
- ret = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
- "regmap-sfr", &syscon);
- if (ret)
- return ERR_PTR(ret);
- utmi = kzalloc(sizeof(*utmi), GFP_KERNEL);
- if (!utmi)
- return ERR_PTR(-ENOMEM);
- utmi->base = base;
- utmi->regmap_sfr = syscon_get_regmap(syscon);
- if (!utmi->regmap_sfr) {
- kfree(utmi);
- return ERR_PTR(-ENODEV);
- }
- clk = &utmi->clk;
- clk->flags = CLK_GET_RATE_NOCACHE;
- ret = clk_register(clk, UBOOT_DM_CLK_AT91_UTMI, name, parent_name);
- if (ret) {
- kfree(utmi);
- clk = ERR_PTR(ret);
- }
- return clk;
- }
- U_BOOT_DRIVER(at91_utmi_clk) = {
- .name = UBOOT_DM_CLK_AT91_UTMI,
- .id = UCLASS_CLK,
- .ops = &utmi_ops,
- .flags = DM_FLAG_PRE_RELOC,
- };
- static int clk_utmi_sama7g5_enable(struct clk *clk)
- {
- struct clk_utmi *utmi = to_clk_utmi(clk);
- ulong parent_rate = clk_get_parent_rate(clk);
- unsigned int val;
- switch (parent_rate) {
- case 16000000:
- val = 0;
- break;
- case 20000000:
- val = 2;
- break;
- case 24000000:
- val = 3;
- break;
- case 32000000:
- val = 5;
- break;
- default:
- debug("UTMICK: unsupported main_xtal rate\n");
- return -EINVAL;
- }
- pmc_write(utmi->base, AT91_PMC_XTALF, val);
- return 0;
- }
- static const struct clk_ops sama7g5_utmi_ops = {
- .enable = clk_utmi_sama7g5_enable,
- .get_rate = clk_utmi_get_rate,
- };
- struct clk *at91_clk_sama7g5_register_utmi(void __iomem *base,
- const char *name, const char *parent_name)
- {
- struct clk_utmi *utmi;
- struct clk *clk;
- int ret;
- if (!base || !name || !parent_name)
- return ERR_PTR(-EINVAL);
- utmi = kzalloc(sizeof(*utmi), GFP_KERNEL);
- if (!utmi)
- return ERR_PTR(-ENOMEM);
- utmi->base = base;
- clk = &utmi->clk;
- ret = clk_register(clk, UBOOT_DM_CLK_AT91_SAMA7G5_UTMI, name,
- parent_name);
- if (ret) {
- kfree(utmi);
- clk = ERR_PTR(ret);
- }
- return clk;
- }
- U_BOOT_DRIVER(at91_sama7g5_utmi_clk) = {
- .name = UBOOT_DM_CLK_AT91_SAMA7G5_UTMI,
- .id = UCLASS_CLK,
- .ops = &sama7g5_utmi_ops,
- .flags = DM_FLAG_PRE_RELOC,
- };
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