drivers/clk/rockchip/clk-ddr.c

   1 /*
   2  * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
   3  * Author: Lin Huang <hl@rock-chips.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/arm-smccc.h>
  17 #include <linux/clk.h>
  18 #include <linux/clk-provider.h>
  19 #include <linux/io.h>
  20 #include <linux/slab.h>
  21 #include <soc/rockchip/rockchip_sip.h>
  22 #include "clk.h"
  23
  24 struct rockchip_ddrclk {
  25         struct clk_hw   hw;
  26         void __iomem    *reg_base;
  27         int             mux_offset;
  28         int             mux_shift;
  29         int             mux_width;
  30         int             div_shift;
  31         int             div_width;
  32         int             ddr_flag;
  33         spinlock_t      *lock;
  34 };
  35
  36 #define to_rockchip_ddrclk_hw(hw) container_of(hw, struct rockchip_ddrclk, hw)
  37
  38 static int rockchip_ddrclk_sip_set_rate(struct clk_hw *hw, unsigned long drate,
  39                                         unsigned long prate)
  40 {
  41         struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
  42         unsigned long flags;
  43         struct arm_smccc_res res;
  44
  45         spin_lock_irqsave(ddrclk->lock, flags);
  46         arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, drate, 0,
  47                       ROCKCHIP_SIP_CONFIG_DRAM_SET_RATE,
  48                       0, 0, 0, 0, &res);
  49         spin_unlock_irqrestore(ddrclk->lock, flags);
  50
  51         return res.a0;
  52 }
  53
  54 static unsigned long
  55 rockchip_ddrclk_sip_recalc_rate(struct clk_hw *hw,
  56                                 unsigned long parent_rate)
  57 {
  58         struct arm_smccc_res res;
  59
  60         arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
  61                       ROCKCHIP_SIP_CONFIG_DRAM_GET_RATE,
  62                       0, 0, 0, 0, &res);
  63
  64         return res.a0;
  65 }
  66
  67 static long rockchip_ddrclk_sip_round_rate(struct clk_hw *hw,
  68                                            unsigned long rate,
  69                                            unsigned long *prate)
  70 {
  71         struct arm_smccc_res res;
  72
  73         arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, rate, 0,
  74                       ROCKCHIP_SIP_CONFIG_DRAM_ROUND_RATE,
  75                       0, 0, 0, 0, &res);
  76
  77         return res.a0;
  78 }
  79
  80 static u8 rockchip_ddrclk_get_parent(struct clk_hw *hw)
  81 {
  82         struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
  83         int num_parents = clk_hw_get_num_parents(hw);
  84         u32 val;
  85
  86         val = clk_readl(ddrclk->reg_base +
  87                         ddrclk->mux_offset) >> ddrclk->mux_shift;
  88         val &= GENMASK(ddrclk->mux_width - 1, 0);
  89
  90         if (val >= num_parents)
  91                 return -EINVAL;
  92
  93         return val;
  94 }
  95
  96 static const struct clk_ops rockchip_ddrclk_sip_ops = {
  97         .recalc_rate = rockchip_ddrclk_sip_recalc_rate,
  98         .set_rate = rockchip_ddrclk_sip_set_rate,
  99         .round_rate = rockchip_ddrclk_sip_round_rate,
 100         .get_parent = rockchip_ddrclk_get_parent,
 101 };
 102
 103 struct clk *rockchip_clk_register_ddrclk(const char *name, int flags,
 104                                          const char *const *parent_names,
 105                                          u8 num_parents, int mux_offset,
 106                                          int mux_shift, int mux_width,
 107                                          int div_shift, int div_width,
 108                                          int ddr_flag, void __iomem *reg_base,
 109                                          spinlock_t *lock)
 110 {
 111         struct rockchip_ddrclk *ddrclk;
 112         struct clk_init_data init;
 113         struct clk *clk;
 114
 115         ddrclk = kzalloc(sizeof(*ddrclk), GFP_KERNEL);
 116         if (!ddrclk)
 117                 return ERR_PTR(-ENOMEM);
 118
 119         init.name = name;
 120         init.parent_names = parent_names;
 121         init.num_parents = num_parents;
 122
 123         init.flags = flags;
 124         init.flags |= CLK_SET_RATE_NO_REPARENT;
 125
 126         switch (ddr_flag) {
 127         case ROCKCHIP_DDRCLK_SIP:
 128                 init.ops = &rockchip_ddrclk_sip_ops;
 129                 break;
 130         default:
 131                 pr_err("%s: unsupported ddrclk type %d\n", __func__, ddr_flag);
 132                 kfree(ddrclk);
 133                 return ERR_PTR(-EINVAL);
 134         }
 135
 136         ddrclk->reg_base = reg_base;
 137         ddrclk->lock = lock;
 138         ddrclk->hw.init = &init;
 139         ddrclk->mux_offset = mux_offset;
 140         ddrclk->mux_shift = mux_shift;
 141         ddrclk->mux_width = mux_width;
 142         ddrclk->div_shift = div_shift;
 143         ddrclk->div_width = div_width;
 144         ddrclk->ddr_flag = ddr_flag;
 145
 146         clk = clk_register(NULL, &ddrclk->hw);
 147         if (IS_ERR(clk))
 148                 kfree(ddrclk);
 149
 150         return clk;
 151 }