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Release 4.11 drivers/clk/tegra/clk-periph-gate.c

/*
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/err.h>

#include <soc/tegra/fuse.h>

#include "clk.h"

static DEFINE_SPINLOCK(periph_ref_lock);

/* Macros to assist peripheral gate clock */

#define read_enb(gate) \
	readl_relaxed(gate->clk_base + (gate->regs->enb_reg))

#define write_enb_set(val, gate) \
	writel_relaxed(val, gate->clk_base + (gate->regs->enb_set_reg))

#define write_enb_clr(val, gate) \
	writel_relaxed(val, gate->clk_base + (gate->regs->enb_clr_reg))


#define read_rst(gate) \
	readl_relaxed(gate->clk_base + (gate->regs->rst_reg))

#define write_rst_clr(val, gate) \
	writel_relaxed(val, gate->clk_base + (gate->regs->rst_clr_reg))


#define periph_clk_to_bit(gate) (1 << (gate->clk_num % 32))


#define LVL2_CLK_GATE_OVRE 0x554

/* Peripheral gate clock ops */

static int clk_periph_is_enabled(struct clk_hw *hw) { struct tegra_clk_periph_gate *gate = to_clk_periph_gate(hw); int state = 1; if (!(read_enb(gate) & periph_clk_to_bit(gate))) state = 0; if (!(gate->flags & TEGRA_PERIPH_NO_RESET)) if (read_rst(gate) & periph_clk_to_bit(gate)) state = 0; return state; }

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Prashant Gaikwad75100.00%1100.00%
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static int clk_periph_enable(struct clk_hw *hw) { struct tegra_clk_periph_gate *gate = to_clk_periph_gate(hw); unsigned long flags = 0; spin_lock_irqsave(&periph_ref_lock, flags); gate->enable_refcnt[gate->clk_num]++; if (gate->enable_refcnt[gate->clk_num] > 1) { spin_unlock_irqrestore(&periph_ref_lock, flags); return 0; } write_enb_set(periph_clk_to_bit(gate), gate); udelay(2); if (!(gate->flags & TEGRA_PERIPH_NO_RESET) && !(gate->flags & TEGRA_PERIPH_MANUAL_RESET)) { if (read_rst(gate) & periph_clk_to_bit(gate)) { udelay(5); /* reset propogation delay */ write_rst_clr(periph_clk_to_bit(gate), gate); } } if (gate->flags & TEGRA_PERIPH_WAR_1005168) { writel_relaxed(0, gate->clk_base + LVL2_CLK_GATE_OVRE); writel_relaxed(BIT(22), gate->clk_base + LVL2_CLK_GATE_OVRE); udelay(1); writel_relaxed(0, gate->clk_base + LVL2_CLK_GATE_OVRE); } spin_unlock_irqrestore(&periph_ref_lock, flags); return 0; }

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Prashant Gaikwad14974.50%150.00%
Peter 'p2' De Schrijver5125.50%150.00%
Total200100.00%2100.00%


static void clk_periph_disable(struct clk_hw *hw) { struct tegra_clk_periph_gate *gate = to_clk_periph_gate(hw); unsigned long flags = 0; spin_lock_irqsave(&periph_ref_lock, flags); gate->enable_refcnt[gate->clk_num]--; if (gate->enable_refcnt[gate->clk_num] > 0) { spin_unlock_irqrestore(&periph_ref_lock, flags); return; } /* * If peripheral is in the APB bus then read the APB bus to * flush the write operation in apb bus. This will avoid the * peripheral access after disabling clock */ if (gate->flags & TEGRA_PERIPH_ON_APB) tegra_read_chipid(); write_enb_clr(periph_clk_to_bit(gate), gate); spin_unlock_irqrestore(&periph_ref_lock, flags); }

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Prashant Gaikwad99100.00%1100.00%
Total99100.00%1100.00%

const struct clk_ops tegra_clk_periph_gate_ops = { .is_enabled = clk_periph_is_enabled, .enable = clk_periph_enable, .disable = clk_periph_disable, };
struct clk *tegra_clk_register_periph_gate(const char *name, const char *parent_name, u8 gate_flags, void __iomem *clk_base, unsigned long flags, int clk_num, int *enable_refcnt) { struct tegra_clk_periph_gate *gate; struct clk *clk; struct clk_init_data init; const struct tegra_clk_periph_regs *pregs; pregs = get_reg_bank(clk_num); if (!pregs) return ERR_PTR(-EINVAL); gate = kzalloc(sizeof(*gate), GFP_KERNEL); if (!gate) { pr_err("%s: could not allocate periph gate clk\n", __func__); return ERR_PTR(-ENOMEM); } init.name = name; init.flags = flags; init.parent_names = parent_name ? &parent_name : NULL; init.num_parents = parent_name ? 1 : 0; init.ops = &tegra_clk_periph_gate_ops; gate->magic = TEGRA_CLK_PERIPH_GATE_MAGIC; gate->clk_base = clk_base; gate->clk_num = clk_num; gate->flags = gate_flags; gate->enable_refcnt = enable_refcnt; gate->regs = pregs; /* Data in .init is copied by clk_register(), so stack variable OK */ gate->hw.init = &init; clk = clk_register(NULL, &gate->hw); if (IS_ERR(clk)) kfree(gate); return clk; }

Contributors

PersonTokensPropCommitsCommitProp
Prashant Gaikwad19788.74%133.33%
Peter 'p2' De Schrijver2410.81%133.33%
Thierry Reding10.45%133.33%
Total222100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Prashant Gaikwad62388.37%116.67%
Peter 'p2' De Schrijver7911.21%233.33%
Thierry Reding20.28%233.33%
Yen Lin10.14%116.67%
Total705100.00%6100.00%
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