kernel/drivers/clk/hisilicon/clkgate-separated.c

   1 /*
   2  * Hisilicon clock separated gate driver
   3  *
   4  * Copyright (c) 2012-2013 Hisilicon Limited.
   5  * Copyright (c) 2012-2013 Linaro Limited.
   6  *
   7  * Author: Haojian Zhuang <haojian.zhuang@linaro.org>
   8  *         Xin Li <li.xin@linaro.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  *
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/clk-provider.h>
  28 #include <linux/io.h>
  29 #include <linux/slab.h>
  30
  31 #include "clk.h"
  32
  33 /* clock separated gate register offset */
  34 #define CLKGATE_SEPERATED_ENABLE                0x0
  35 #define CLKGATE_SEPERATED_DISABLE               0x4
  36 #define CLKGATE_SEPERATED_STATUS                0x8
  37
  38 struct clkgate_separated {
  39         struct clk_hw   hw;
  40         void __iomem    *enable;        /* enable register */
  41         u8              bit_idx;        /* bits in enable/disable register */
  42         u8              flags;
  43         spinlock_t      *lock;
  44 };
  45
  46 static int clkgate_separated_enable(struct clk_hw *hw)
  47 {
  48         struct clkgate_separated *sclk;
  49         unsigned long flags = 0;
  50         u32 reg;
  51
  52         sclk = container_of(hw, struct clkgate_separated, hw);
  53         if (sclk->lock)
  54                 spin_lock_irqsave(sclk->lock, flags);
  55         reg = BIT(sclk->bit_idx);
  56         writel_relaxed(reg, sclk->enable);
  57         readl_relaxed(sclk->enable + CLKGATE_SEPERATED_STATUS);
  58         if (sclk->lock)
  59                 spin_unlock_irqrestore(sclk->lock, flags);
  60         return 0;
  61 }
  62
  63 static void clkgate_separated_disable(struct clk_hw *hw)
  64 {
  65         struct clkgate_separated *sclk;
  66         unsigned long flags = 0;
  67         u32 reg;
  68
  69         sclk = container_of(hw, struct clkgate_separated, hw);
  70         if (sclk->lock)
  71                 spin_lock_irqsave(sclk->lock, flags);
  72         reg = BIT(sclk->bit_idx);
  73         writel_relaxed(reg, sclk->enable + CLKGATE_SEPERATED_DISABLE);
  74         readl_relaxed(sclk->enable + CLKGATE_SEPERATED_STATUS);
  75         if (sclk->lock)
  76                 spin_unlock_irqrestore(sclk->lock, flags);
  77 }
  78
  79 static int clkgate_separated_is_enabled(struct clk_hw *hw)
  80 {
  81         struct clkgate_separated *sclk;
  82         u32 reg;
  83
  84         sclk = container_of(hw, struct clkgate_separated, hw);
  85         reg = readl_relaxed(sclk->enable + CLKGATE_SEPERATED_STATUS);
  86         reg &= BIT(sclk->bit_idx);
  87
  88         return reg ? 1 : 0;
  89 }
  90
  91 static struct clk_ops clkgate_separated_ops = {
  92         .enable         = clkgate_separated_enable,
  93         .disable        = clkgate_separated_disable,
  94         .is_enabled     = clkgate_separated_is_enabled,
  95 };
  96
  97 struct clk *hisi_register_clkgate_sep(struct device *dev, const char *name,
  98                                       const char *parent_name,
  99                                       unsigned long flags,
 100                                       void __iomem *reg, u8 bit_idx,
 101                                       u8 clk_gate_flags, spinlock_t *lock)
 102 {
 103         struct clkgate_separated *sclk;
 104         struct clk *clk;
 105         struct clk_init_data init;
 106
 107         sclk = kzalloc(sizeof(*sclk), GFP_KERNEL);
 108         if (!sclk) {
 109                 pr_err("%s: fail to allocate separated gated clk\n", __func__);
 110                 return ERR_PTR(-ENOMEM);
 111         }
 112
 113         init.name = name;
 114         init.ops = &clkgate_separated_ops;
 115         init.flags = flags | CLK_IS_BASIC;
 116         init.parent_names = (parent_name ? &parent_name : NULL);
 117         init.num_parents = (parent_name ? 1 : 0);
 118
 119         sclk->enable = reg + CLKGATE_SEPERATED_ENABLE;
 120         sclk->bit_idx = bit_idx;
 121         sclk->flags = clk_gate_flags;
 122         sclk->hw.init = &init;
 123
 124         clk = clk_register(dev, &sclk->hw);
 125         if (IS_ERR(clk))
 126                 kfree(sclk);
 127         return clk;
 128 }