drivers/clk/hisilicon/clkdivider-hi6220.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Hisilicon hi6220 SoC divider clock driver
   4  *
   5  * Copyright (c) 2015 Hisilicon Limited.
   6  *
   7  * Author: Bintian Wang <bintian.wang@huawei.com>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/clk-provider.h>
  12 #include <linux/slab.h>
  13 #include <linux/io.h>
  14 #include <linux/err.h>
  15 #include <linux/spinlock.h>
  16
  17 #include "clk.h"
  18
  19 #define div_mask(width) ((1 << (width)) - 1)
  20
  21 /**
  22  * struct hi6220_clk_divider - divider clock for hi6220
  23  *
  24  * @hw:         handle between common and hardware-specific interfaces
  25  * @reg:        register containing divider
  26  * @shift:      shift to the divider bit field
  27  * @width:      width of the divider bit field
  28  * @mask:       mask for setting divider rate
  29  * @table:      the div table that the divider supports
  30  * @lock:       register lock
  31  */
  32 struct hi6220_clk_divider {
  33         struct clk_hw   hw;
  34         void __iomem    *reg;
  35         u8              shift;
  36         u8              width;
  37         u32             mask;
  38         const struct clk_div_table *table;
  39         spinlock_t      *lock;
  40 };
  41
  42 #define to_hi6220_clk_divider(_hw)      \
  43         container_of(_hw, struct hi6220_clk_divider, hw)
  44
  45 static unsigned long hi6220_clkdiv_recalc_rate(struct clk_hw *hw,
  46                                         unsigned long parent_rate)
  47 {
  48         unsigned int val;
  49         struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
  50
  51         val = readl_relaxed(dclk->reg) >> dclk->shift;
  52         val &= div_mask(dclk->width);
  53
  54         return divider_recalc_rate(hw, parent_rate, val, dclk->table,
  55                                    CLK_DIVIDER_ROUND_CLOSEST, dclk->width);
  56 }
  57
  58 static long hi6220_clkdiv_round_rate(struct clk_hw *hw, unsigned long rate,
  59                                         unsigned long *prate)
  60 {
  61         struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
  62
  63         return divider_round_rate(hw, rate, prate, dclk->table,
  64                                   dclk->width, CLK_DIVIDER_ROUND_CLOSEST);
  65 }
  66
  67 static int hi6220_clkdiv_set_rate(struct clk_hw *hw, unsigned long rate,
  68                                         unsigned long parent_rate)
  69 {
  70         int value;
  71         unsigned long flags = 0;
  72         u32 data;
  73         struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
  74
  75         value = divider_get_val(rate, parent_rate, dclk->table,
  76                                 dclk->width, CLK_DIVIDER_ROUND_CLOSEST);
  77
  78         if (dclk->lock)
  79                 spin_lock_irqsave(dclk->lock, flags);
  80
  81         data = readl_relaxed(dclk->reg);
  82         data &= ~(div_mask(dclk->width) << dclk->shift);
  83         data |= value << dclk->shift;
  84         data |= dclk->mask;
  85
  86         writel_relaxed(data, dclk->reg);
  87
  88         if (dclk->lock)
  89                 spin_unlock_irqrestore(dclk->lock, flags);
  90
  91         return 0;
  92 }
  93
  94 static const struct clk_ops hi6220_clkdiv_ops = {
  95         .recalc_rate = hi6220_clkdiv_recalc_rate,
  96         .round_rate = hi6220_clkdiv_round_rate,
  97         .set_rate = hi6220_clkdiv_set_rate,
  98 };
  99
 100 struct clk *hi6220_register_clkdiv(struct device *dev, const char *name,
 101         const char *parent_name, unsigned long flags, void __iomem *reg,
 102         u8 shift, u8 width, u32 mask_bit, spinlock_t *lock)
 103 {
 104         struct hi6220_clk_divider *div;
 105         struct clk *clk;
 106         struct clk_init_data init;
 107         struct clk_div_table *table;
 108         u32 max_div, min_div;
 109         int i;
 110
 111         /* allocate the divider */
 112         div = kzalloc(sizeof(*div), GFP_KERNEL);
 113         if (!div)
 114                 return ERR_PTR(-ENOMEM);
 115
 116         /* Init the divider table */
 117         max_div = div_mask(width) + 1;
 118         min_div = 1;
 119
 120         table = kcalloc(max_div + 1, sizeof(*table), GFP_KERNEL);
 121         if (!table) {
 122                 kfree(div);
 123                 return ERR_PTR(-ENOMEM);
 124         }
 125
 126         for (i = 0; i < max_div; i++) {
 127                 table[i].div = min_div + i;
 128                 table[i].val = table[i].div - 1;
 129         }
 130
 131         init.name = name;
 132         init.ops = &hi6220_clkdiv_ops;
 133         init.flags = flags;
 134         init.parent_names = parent_name ? &parent_name : NULL;
 135         init.num_parents = parent_name ? 1 : 0;
 136
 137         /* struct hi6220_clk_divider assignments */
 138         div->reg = reg;
 139         div->shift = shift;
 140         div->width = width;
 141         div->mask = mask_bit ? BIT(mask_bit) : 0;
 142         div->lock = lock;
 143         div->hw.init = &init;
 144         div->table = table;
 145
 146         /* register the clock */
 147         clk = clk_register(dev, &div->hw);
 148         if (IS_ERR(clk)) {
 149                 kfree(table);
 150                 kfree(div);
 151         }
 152
 153         return clk;
 154 }