drivers/clk/socfpga/clk-pll-a10.c

   1 /*
   2  * Copyright (C) 2015 Altera Corporation. All rights reserved
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it 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 along with
  14  * this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #include <linux/slab.h>
  17 #include <linux/clk-provider.h>
  18 #include <linux/io.h>
  19 #include <linux/of.h>
  20 #include <linux/of_address.h>
  21
  22 #include "clk.h"
  23
  24 /* Clock Manager offsets */
  25 #define CLK_MGR_PLL_CLK_SRC_SHIFT       8
  26 #define CLK_MGR_PLL_CLK_SRC_MASK        0x3
  27
  28 /* Clock bypass bits */
  29 #define SOCFPGA_PLL_BG_PWRDWN           0
  30 #define SOCFPGA_PLL_PWR_DOWN            1
  31 #define SOCFPGA_PLL_EXT_ENA             2
  32 #define SOCFPGA_PLL_DIVF_MASK           0x00001FFF
  33 #define SOCFPGA_PLL_DIVF_SHIFT  0
  34 #define SOCFPGA_PLL_DIVQ_MASK           0x003F0000
  35 #define SOCFPGA_PLL_DIVQ_SHIFT  16
  36 #define SOCFGPA_MAX_PARENTS     5
  37
  38 #define SOCFPGA_MAIN_PLL_CLK            "main_pll"
  39 #define SOCFPGA_PERIP_PLL_CLK           "periph_pll"
  40
  41 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
  42
  43 void __iomem *clk_mgr_a10_base_addr;
  44
  45 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
  46                                          unsigned long parent_rate)
  47 {
  48         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  49         unsigned long divf, divq, reg;
  50         unsigned long long vco_freq;
  51
  52         /* read VCO1 reg for numerator and denominator */
  53         reg = readl(socfpgaclk->hw.reg + 0x4);
  54         divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
  55         divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
  56         vco_freq = (unsigned long long)parent_rate * (divf + 1);
  57         do_div(vco_freq, (1 + divq));
  58         return (unsigned long)vco_freq;
  59 }
  60
  61 static u8 clk_pll_get_parent(struct clk_hw *hwclk)
  62 {
  63         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  64         u32 pll_src;
  65
  66         pll_src = readl(socfpgaclk->hw.reg);
  67
  68         return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
  69                 CLK_MGR_PLL_CLK_SRC_MASK;
  70 }
  71
  72 static struct clk_ops clk_pll_ops = {
  73         .recalc_rate = clk_pll_recalc_rate,
  74         .get_parent = clk_pll_get_parent,
  75 };
  76
  77 static struct clk * __init __socfpga_pll_init(struct device_node *node,
  78         const struct clk_ops *ops)
  79 {
  80         u32 reg;
  81         struct clk *clk;
  82         struct socfpga_pll *pll_clk;
  83         const char *clk_name = node->name;
  84         const char *parent_name[SOCFGPA_MAX_PARENTS];
  85         struct clk_init_data init;
  86         struct device_node *clkmgr_np;
  87         int rc;
  88         int i = 0;
  89
  90         of_property_read_u32(node, "reg", &reg);
  91
  92         pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
  93         if (WARN_ON(!pll_clk))
  94                 return NULL;
  95
  96         clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
  97         clk_mgr_a10_base_addr = of_iomap(clkmgr_np, 0);
  98         BUG_ON(!clk_mgr_a10_base_addr);
  99         pll_clk->hw.reg = clk_mgr_a10_base_addr + reg;
 100
 101         of_property_read_string(node, "clock-output-names", &clk_name);
 102
 103         init.name = clk_name;
 104         init.ops = ops;
 105         init.flags = 0;
 106
 107         while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] =
 108                         of_clk_get_parent_name(node, i)) != NULL)
 109                 i++;
 110         init.num_parents = i;
 111         init.parent_names = parent_name;
 112         pll_clk->hw.hw.init = &init;
 113
 114         pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
 115         clk_pll_ops.enable = clk_gate_ops.enable;
 116         clk_pll_ops.disable = clk_gate_ops.disable;
 117
 118         clk = clk_register(NULL, &pll_clk->hw.hw);
 119         if (WARN_ON(IS_ERR(clk))) {
 120                 kfree(pll_clk);
 121                 return NULL;
 122         }
 123         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 124         return clk;
 125 }
 126
 127 void __init socfpga_a10_pll_init(struct device_node *node)
 128 {
 129         __socfpga_pll_init(node, &clk_pll_ops);
 130 }