drivers/clk/socfpga/clk-gate-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/mfd/syscon.h>
  20 #include <linux/of.h>
  21 #include <linux/regmap.h>
  22
  23 #include "clk.h"
  24
  25 #define streq(a, b) (strcmp((a), (b)) == 0)
  26
  27 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  28
  29 /* SDMMC Group for System Manager defines */
  30 #define SYSMGR_SDMMCGRP_CTRL_OFFSET     0x28
  31
  32 static unsigned long socfpga_gate_clk_recalc_rate(struct clk_hw *hwclk,
  33         unsigned long parent_rate)
  34 {
  35         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  36         u32 div = 1, val;
  37
  38         if (socfpgaclk->fixed_div)
  39                 div = socfpgaclk->fixed_div;
  40         else if (socfpgaclk->div_reg) {
  41                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  42                 val &= GENMASK(socfpgaclk->width - 1, 0);
  43                 div = (1 << val);
  44         }
  45
  46         return parent_rate / div;
  47 }
  48
  49 static int socfpga_clk_prepare(struct clk_hw *hwclk)
  50 {
  51         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  52         int i;
  53         u32 hs_timing;
  54         u32 clk_phase[2];
  55
  56         if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
  57                 for (i = 0; i < ARRAY_SIZE(clk_phase); i++) {
  58                         switch (socfpgaclk->clk_phase[i]) {
  59                         case 0:
  60                                 clk_phase[i] = 0;
  61                                 break;
  62                         case 45:
  63                                 clk_phase[i] = 1;
  64                                 break;
  65                         case 90:
  66                                 clk_phase[i] = 2;
  67                                 break;
  68                         case 135:
  69                                 clk_phase[i] = 3;
  70                                 break;
  71                         case 180:
  72                                 clk_phase[i] = 4;
  73                                 break;
  74                         case 225:
  75                                 clk_phase[i] = 5;
  76                                 break;
  77                         case 270:
  78                                 clk_phase[i] = 6;
  79                                 break;
  80                         case 315:
  81                                 clk_phase[i] = 7;
  82                                 break;
  83                         default:
  84                                 clk_phase[i] = 0;
  85                                 break;
  86                         }
  87                 }
  88
  89                 hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
  90                 if (!IS_ERR(socfpgaclk->sys_mgr_base_addr))
  91                         regmap_write(socfpgaclk->sys_mgr_base_addr,
  92                                      SYSMGR_SDMMCGRP_CTRL_OFFSET, hs_timing);
  93                 else
  94                         pr_err("%s: cannot set clk_phase because sys_mgr_base_addr is not available!\n",
  95                                         __func__);
  96         }
  97         return 0;
  98 }
  99
 100 static struct clk_ops gateclk_ops = {
 101         .prepare = socfpga_clk_prepare,
 102         .recalc_rate = socfpga_gate_clk_recalc_rate,
 103 };
 104
 105 static void __init __socfpga_gate_init(struct device_node *node,
 106         const struct clk_ops *ops)
 107 {
 108         u32 clk_gate[2];
 109         u32 div_reg[3];
 110         u32 clk_phase[2];
 111         u32 fixed_div;
 112         struct clk *clk;
 113         struct socfpga_gate_clk *socfpga_clk;
 114         const char *clk_name = node->name;
 115         const char *parent_name[SOCFPGA_MAX_PARENTS];
 116         struct clk_init_data init;
 117         int rc;
 118
 119         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 120         if (WARN_ON(!socfpga_clk))
 121                 return;
 122
 123         rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 124         if (rc)
 125                 clk_gate[0] = 0;
 126
 127         if (clk_gate[0]) {
 128                 socfpga_clk->hw.reg = clk_mgr_a10_base_addr + clk_gate[0];
 129                 socfpga_clk->hw.bit_idx = clk_gate[1];
 130
 131                 gateclk_ops.enable = clk_gate_ops.enable;
 132                 gateclk_ops.disable = clk_gate_ops.disable;
 133         }
 134
 135         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 136         if (rc)
 137                 socfpga_clk->fixed_div = 0;
 138         else
 139                 socfpga_clk->fixed_div = fixed_div;
 140
 141         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 142         if (!rc) {
 143                 socfpga_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
 144                 socfpga_clk->shift = div_reg[1];
 145                 socfpga_clk->width = div_reg[2];
 146         } else {
 147                 socfpga_clk->div_reg = NULL;
 148         }
 149
 150         rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
 151         if (!rc) {
 152                 socfpga_clk->clk_phase[0] = clk_phase[0];
 153                 socfpga_clk->clk_phase[1] = clk_phase[1];
 154
 155                 socfpga_clk->sys_mgr_base_addr =
 156                         syscon_regmap_lookup_by_compatible("altr,sys-mgr");
 157                 if (IS_ERR(socfpga_clk->sys_mgr_base_addr)) {
 158                         pr_err("%s: failed to find altr,sys-mgr regmap!\n",
 159                                         __func__);
 160                         return;
 161                 }
 162         }
 163
 164         of_property_read_string(node, "clock-output-names", &clk_name);
 165
 166         init.name = clk_name;
 167         init.ops = ops;
 168         init.flags = 0;
 169
 170         init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 171         init.parent_names = parent_name;
 172         socfpga_clk->hw.hw.init = &init;
 173
 174         clk = clk_register(NULL, &socfpga_clk->hw.hw);
 175         if (WARN_ON(IS_ERR(clk))) {
 176                 kfree(socfpga_clk);
 177                 return;
 178         }
 179         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 180         if (WARN_ON(rc))
 181                 return;
 182 }
 183
 184 void __init socfpga_a10_gate_init(struct device_node *node)
 185 {
 186         __socfpga_gate_init(node, &gateclk_ops);
 187 }