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Release 4.16 drivers/clk/at91/clk-utmi.c

Directory: drivers/clk/at91
/*
 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <soc/at91/atmel-sfr.h>

#include "pmc.h"

/*
 * 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 {
	
struct clk_hw hw;
	
struct regmap *regmap_pmc;
	
struct regmap *regmap_sfr;
};


#define to_clk_utmi(hw) container_of(hw, struct clk_utmi, hw)


static inline bool clk_utmi_ready(struct regmap *regmap) { unsigned int status; regmap_read(regmap, AT91_PMC_SR, &status); return status & AT91_PMC_LOCKU; }

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static int clk_utmi_prepare(struct clk_hw *hw) { struct clk_hw *hw_parent; struct clk_utmi *utmi = to_clk_utmi(hw); unsigned int uckr = AT91_PMC_UPLLEN | AT91_PMC_UPLLCOUNT | AT91_PMC_BIASEN; unsigned int utmi_ref_clk_freq; unsigned long parent_rate; /* * 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. */ hw_parent = clk_hw_get_parent(hw); parent_rate = clk_hw_get_rate(hw_parent); 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: pr_err("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) { pr_err("UTMICK: sfr node required\n"); return -EINVAL; } regmap_update_bits(utmi->regmap_pmc, AT91_CKGR_UCKR, uckr, uckr); while (!clk_utmi_ready(utmi->regmap_pmc)) cpu_relax(); return 0; }

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Ludovic Desroches11666.67%125.00%
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Alexandre Belloni21.15%125.00%
Total174100.00%4100.00%


static int clk_utmi_is_prepared(struct clk_hw *hw) { struct clk_utmi *utmi = to_clk_utmi(hw); return clk_utmi_ready(utmi->regmap_pmc); }

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static void clk_utmi_unprepare(struct clk_hw *hw) { struct clk_utmi *utmi = to_clk_utmi(hw); regmap_update_bits(utmi->regmap_pmc, AT91_CKGR_UCKR, AT91_PMC_UPLLEN, 0); }

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Boris Brezillon3294.12%250.00%
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Ludovic Desroches12.94%125.00%
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static unsigned long clk_utmi_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { /* UTMI clk rate is fixed. */ return UTMI_RATE; }

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static const struct clk_ops utmi_ops = { .prepare = clk_utmi_prepare, .unprepare = clk_utmi_unprepare, .is_prepared = clk_utmi_is_prepared, .recalc_rate = clk_utmi_recalc_rate, };
static struct clk_hw * __init at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr, const char *name, const char *parent_name) { struct clk_utmi *utmi; struct clk_hw *hw; struct clk_init_data init; int ret; utmi = kzalloc(sizeof(*utmi), GFP_KERNEL); if (!utmi) return ERR_PTR(-ENOMEM); init.name = name; init.ops = &utmi_ops; init.parent_names = parent_name ? &parent_name : NULL; init.num_parents = parent_name ? 1 : 0; init.flags = CLK_SET_RATE_GATE; utmi->hw.init = &init; utmi->regmap_pmc = regmap_pmc; utmi->regmap_sfr = regmap_sfr; hw = &utmi->hw; ret = clk_hw_register(NULL, &utmi->hw); if (ret) { kfree(utmi); hw = ERR_PTR(ret); } return hw; }

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Boris Brezillon13377.33%250.00%
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static void __init of_at91sam9x5_clk_utmi_setup(struct device_node *np) { struct clk_hw *hw; const char *parent_name; const char *name = np->name; struct regmap *regmap_pmc, *regmap_sfr; parent_name = of_clk_get_parent_name(np, 0); of_property_read_string(np, "clock-output-names", &name); regmap_pmc = syscon_node_to_regmap(of_get_parent(np)); if (IS_ERR(regmap_pmc)) return; /* * If the device supports different mainck rates, this value has to be * set in the UTMI Clock Trimming register. * - 9x5: mainck supports several rates but it is indicated that a * 12 MHz is needed in case of USB. * - sama5d3 and sama5d2: mainck supports several rates. Configuring * the FREQ field of the UTMI Clock Trimming register is mandatory. * - sama5d4: mainck is at 12 MHz. * * We only need to retrieve sama5d3 or sama5d2 sfr regmap. */ regmap_sfr = syscon_regmap_lookup_by_compatible("atmel,sama5d3-sfr"); if (IS_ERR(regmap_sfr)) { regmap_sfr = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); if (IS_ERR(regmap_sfr)) regmap_sfr = NULL; } hw = at91_clk_register_utmi(regmap_pmc, regmap_sfr, name, parent_name); if (IS_ERR(hw)) return; of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); return; }

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Boris Brezillon9164.08%250.00%
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Stephen Boyd74.93%125.00%
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CLK_OF_DECLARE(at91sam9x5_clk_utmi, "atmel,at91sam9x5-clk-utmi", of_at91sam9x5_clk_utmi_setup);

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Boris Brezillon47167.77%233.33%
Ludovic Desroches18827.05%116.67%
Stephen Boyd334.75%116.67%
Alexandre Belloni30.43%233.33%
Total695100.00%6100.00%
Directory: drivers/clk/at91
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