LXR linux/drivers/clk/tegra/clk-pll-out.c

   1/*
   2 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope it will be useful, but WITHOUT
   9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11 * more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17#include <linux/kernel.h>
  18#include <linux/io.h>
  19#include <linux/err.h>
  20#include <linux/delay.h>
  21#include <linux/slab.h>
  22#include <linux/clk-provider.h>
  23#include <linux/clk.h>
  24
  25#include "clk.h"
  26
  27#define pll_out_enb(p) (BIT(p->enb_bit_idx))
  28#define pll_out_rst(p) (BIT(p->rst_bit_idx))
  29
  30static int clk_pll_out_is_enabled(struct clk_hw *hw)
  31{
  32        struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
  33        u32 val = readl_relaxed(pll_out->reg);
  34        int state;
  35
  36        state = (val & pll_out_enb(pll_out)) ? 1 : 0;
  37        if (!(val & (pll_out_rst(pll_out))))
  38                state = 0;
  39        return state;
  40}
  41
  42static int clk_pll_out_enable(struct clk_hw *hw)
  43{
  44        struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
  45        unsigned long flags = 0;
  46        u32 val;
  47
  48        if (pll_out->lock)
  49                spin_lock_irqsave(pll_out->lock, flags);
  50
  51        val = readl_relaxed(pll_out->reg);
  52
  53        val |= (pll_out_enb(pll_out) | pll_out_rst(pll_out));
  54
  55        writel_relaxed(val, pll_out->reg);
  56        udelay(2);
  57
  58        if (pll_out->lock)
  59                spin_unlock_irqrestore(pll_out->lock, flags);
  60
  61        return 0;
  62}
  63
  64static void clk_pll_out_disable(struct clk_hw *hw)
  65{
  66        struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
  67        unsigned long flags = 0;
  68        u32 val;
  69
  70        if (pll_out->lock)
  71                spin_lock_irqsave(pll_out->lock, flags);
  72
  73        val = readl_relaxed(pll_out->reg);
  74
  75        val &= ~(pll_out_enb(pll_out) | pll_out_rst(pll_out));
  76
  77        writel_relaxed(val, pll_out->reg);
  78        udelay(2);
  79
  80        if (pll_out->lock)
  81                spin_unlock_irqrestore(pll_out->lock, flags);
  82}
  83
  84const struct clk_ops tegra_clk_pll_out_ops = {
  85        .is_enabled = clk_pll_out_is_enabled,
  86        .enable = clk_pll_out_enable,
  87        .disable = clk_pll_out_disable,
  88};
  89
  90struct clk *tegra_clk_register_pll_out(const char *name,
  91                const char *parent_name, void __iomem *reg, u8 enb_bit_idx,
  92                u8 rst_bit_idx, unsigned long flags, u8 pll_out_flags,
  93                spinlock_t *lock)
  94{
  95        struct tegra_clk_pll_out *pll_out;
  96        struct clk *clk;
  97        struct clk_init_data init;
  98
  99        pll_out = kzalloc(sizeof(*pll_out), GFP_KERNEL);
 100        if (!pll_out)
 101                return ERR_PTR(-ENOMEM);
 102
 103        init.name = name;
 104        init.ops = &tegra_clk_pll_out_ops;
 105        init.parent_names = (parent_name ? &parent_name : NULL);
 106        init.num_parents = (parent_name ? 1 : 0);
 107        init.flags = flags;
 108
 109        pll_out->reg = reg;
 110        pll_out->enb_bit_idx = enb_bit_idx;
 111        pll_out->rst_bit_idx = rst_bit_idx;
 112        pll_out->flags = pll_out_flags;
 113        pll_out->lock = lock;
 114
 115        /* Data in .init is copied by clk_register(), so stack variable OK */
 116        pll_out->hw.init = &init;
 117
 118        clk = clk_register(NULL, &pll_out->hw);
 119        if (IS_ERR(clk))
 120                kfree(pll_out);
 121
 122        return clk;
 123}
 124