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/clk-provider.h>
  17 #include <linux/io.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/of.h>
  20 #include <linux/regmap.h>
  21
  22 #include "clk.h"
  23
  24 #define streq(a, b) (strcmp((a), (b)) == 0)
  25
  26 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  27
  28 /* SDMMC Group for System Manager defines */
  29 #define SYSMGR_SDMMCGRP_CTRL_OFFSET     0x28
  30
  31 static unsigned long socfpga_gate_clk_recalc_rate(struct clk_hw *hwclk,
  32         unsigned long parent_rate)
  33 {
  34         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  35         u32 div = 1, val;
  36
  37         if (socfpgaclk->fixed_div)
  38                 div = socfpgaclk->fixed_div;
  39         else if (socfpgaclk->div_reg) {
  40                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  41                 val &= div_mask(socfpgaclk->width);
  42                 div = (1 << val);
  43         }
  44
  45         return parent_rate / div;
  46 }
  47
  48 static int socfpga_clk_prepare(struct clk_hw *hwclk)
  49 {
  50         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  51         int i;
  52         u32 hs_timing;
  53         u32 clk_phase[2];
  54
  55         if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
  56                 for (i = 0; i < ARRAY_SIZE(clk_phase); i++) {
  57                         switch (socfpgaclk->clk_phase[i]) {
  58                         case 0:
  59                                 clk_phase[i] = 0;
  60                                 break;
  61                         case 45:
  62                                 clk_phase[i] = 1;
  63                                 break;
  64                         case 90:
  65                                 clk_phase[i] = 2;
  66                                 break;
  67                         case 135:
  68                                 clk_phase[i] = 3;
  69                                 break;
  70                         case 180:
  71                                 clk_phase[i] = 4;
  72                                 break;
  73                         case 225:
  74                                 clk_phase[i] = 5;
  75                                 break;
  76                         case 270:
  77                                 clk_phase[i] = 6;
  78                                 break;
  79                         case 315:
  80                                 clk_phase[i] = 7;
  81                                 break;
  82                         default:
  83                                 clk_phase[i] = 0;
  84                                 break;
  85                         }
  86                 }
  87
  88                 hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
  89                 if (!IS_ERR(socfpgaclk->sys_mgr_base_addr))
  90                         regmap_write(socfpgaclk->sys_mgr_base_addr,
  91                                      SYSMGR_SDMMCGRP_CTRL_OFFSET, hs_timing);
  92                 else
  93                         pr_err("%s: cannot set clk_phase because sys_mgr_base_addr is not available!\n",
  94                                         __func__);
  95         }
  96         return 0;
  97 }
  98
  99 static struct clk_ops gateclk_ops = {
 100         .prepare = socfpga_clk_prepare,
 101         .recalc_rate = socfpga_gate_clk_recalc_rate,
 102 };
 103
 104 static void __init __socfpga_gate_init(struct device_node *node,
 105         const struct clk_ops *ops)
 106 {
 107         u32 clk_gate[2];
 108         u32 div_reg[3];
 109         u32 clk_phase[2];
 110         u32 fixed_div;
 111         struct clk *clk;
 112         struct socfpga_gate_clk *socfpga_clk;
 113         const char *clk_name = node->name;
 114         const char *parent_name[SOCFPGA_MAX_PARENTS];
 115         struct clk_init_data init;
 116         int rc;
 117         int i = 0;
 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         while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] =
 170                         of_clk_get_parent_name(node, i)) != NULL)
 171                 i++;
 172
 173         init.parent_names = parent_name;
 174         init.num_parents = i;
 175         socfpga_clk->hw.hw.init = &init;
 176
 177         clk = clk_register(NULL, &socfpga_clk->hw.hw);
 178         if (WARN_ON(IS_ERR(clk))) {
 179                 kfree(socfpga_clk);
 180                 return;
 181         }
 182         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 183         if (WARN_ON(rc))
 184                 return;
 185 }
 186
 187 void __init socfpga_a10_gate_init(struct device_node *node)
 188 {
 189         __socfpga_gate_init(node, &gateclk_ops);
 190 }