drivers/clk/socfpga/clk-gate.c

   1 /*
   2  *  Copyright 2011-2012 Calxeda, Inc.
   3  *  Copyright (C) 2012-2013 Altera Corporation <www.altera.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  * Based from clk-highbank.c
  16  *
  17  */
  18 #include <linux/slab.h>
  19 #include <linux/clk-provider.h>
  20 #include <linux/io.h>
  21 #include <linux/mfd/syscon.h>
  22 #include <linux/of.h>
  23 #include <linux/regmap.h>
  24
  25 #include "clk.h"
  26
  27 #define SOCFPGA_L4_MP_CLK               "l4_mp_clk"
  28 #define SOCFPGA_L4_SP_CLK               "l4_sp_clk"
  29 #define SOCFPGA_NAND_CLK                "nand_clk"
  30 #define SOCFPGA_NAND_X_CLK              "nand_x_clk"
  31 #define SOCFPGA_MMC_CLK                 "sdmmc_clk"
  32 #define SOCFPGA_GPIO_DB_CLK_OFFSET      0xA8
  33
  34 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  35
  36 /* SDMMC Group for System Manager defines */
  37 #define SYSMGR_SDMMCGRP_CTRL_OFFSET    0x108
  38
  39 static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
  40 {
  41         u32 l4_src;
  42         u32 perpll_src;
  43
  44         if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
  45                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  46                 return l4_src &= 0x1;
  47         }
  48         if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
  49                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  50                 return !!(l4_src & 2);
  51         }
  52
  53         perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  54         if (streq(hwclk->init->name, SOCFPGA_MMC_CLK))
  55                 return perpll_src &= 0x3;
  56         if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
  57                         streq(hwclk->init->name, SOCFPGA_NAND_X_CLK))
  58                         return (perpll_src >> 2) & 3;
  59
  60         /* QSPI clock */
  61         return (perpll_src >> 4) & 3;
  62
  63 }
  64
  65 static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
  66 {
  67         u32 src_reg;
  68
  69         if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
  70                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  71                 src_reg &= ~0x1;
  72                 src_reg |= parent;
  73                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  74         } else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
  75                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  76                 src_reg &= ~0x2;
  77                 src_reg |= (parent << 1);
  78                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  79         } else {
  80                 src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  81                 if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) {
  82                         src_reg &= ~0x3;
  83                         src_reg |= parent;
  84                 } else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
  85                         streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) {
  86                         src_reg &= ~0xC;
  87                         src_reg |= (parent << 2);
  88                 } else {/* QSPI clock */
  89                         src_reg &= ~0x30;
  90                         src_reg |= (parent << 4);
  91                 }
  92                 writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  93         }
  94
  95         return 0;
  96 }
  97
  98 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
  99         unsigned long parent_rate)
 100 {
 101         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 102         u32 div = 1, val;
 103
 104         if (socfpgaclk->fixed_div)
 105                 div = socfpgaclk->fixed_div;
 106         else if (socfpgaclk->div_reg) {
 107                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
 108                 val &= GENMASK(socfpgaclk->width - 1, 0);
 109                 /* Check for GPIO_DB_CLK by its offset */
 110                 if ((int) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
 111                         div = val + 1;
 112                 else
 113                         div = (1 << val);
 114         }
 115
 116         return parent_rate / div;
 117 }
 118
 119 static int socfpga_clk_prepare(struct clk_hw *hwclk)
 120 {
 121         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 122         struct regmap *sys_mgr_base_addr;
 123         int i;
 124         u32 hs_timing;
 125         u32 clk_phase[2];
 126
 127         if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
 128                 sys_mgr_base_addr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
 129                 if (IS_ERR(sys_mgr_base_addr)) {
 130                         pr_err("%s: failed to find altr,sys-mgr regmap!\n", __func__);
 131                         return -EINVAL;
 132                 }
 133
 134                 for (i = 0; i < 2; i++) {
 135                         switch (socfpgaclk->clk_phase[i]) {
 136                         case 0:
 137                                 clk_phase[i] = 0;
 138                                 break;
 139                         case 45:
 140                                 clk_phase[i] = 1;
 141                                 break;
 142                         case 90:
 143                                 clk_phase[i] = 2;
 144                                 break;
 145                         case 135:
 146                                 clk_phase[i] = 3;
 147                                 break;
 148                         case 180:
 149                                 clk_phase[i] = 4;
 150                                 break;
 151                         case 225:
 152                                 clk_phase[i] = 5;
 153                                 break;
 154                         case 270:
 155                                 clk_phase[i] = 6;
 156                                 break;
 157                         case 315:
 158                                 clk_phase[i] = 7;
 159                                 break;
 160                         default:
 161                                 clk_phase[i] = 0;
 162                                 break;
 163                         }
 164                 }
 165                 hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
 166                 regmap_write(sys_mgr_base_addr, SYSMGR_SDMMCGRP_CTRL_OFFSET,
 167                         hs_timing);
 168         }
 169         return 0;
 170 }
 171
 172 static struct clk_ops gateclk_ops = {
 173         .prepare = socfpga_clk_prepare,
 174         .recalc_rate = socfpga_clk_recalc_rate,
 175         .get_parent = socfpga_clk_get_parent,
 176         .set_parent = socfpga_clk_set_parent,
 177 };
 178
 179 static void __init __socfpga_gate_init(struct device_node *node,
 180         const struct clk_ops *ops)
 181 {
 182         u32 clk_gate[2];
 183         u32 div_reg[3];
 184         u32 clk_phase[2];
 185         u32 fixed_div;
 186         struct clk *clk;
 187         struct socfpga_gate_clk *socfpga_clk;
 188         const char *clk_name = node->name;
 189         const char *parent_name[SOCFPGA_MAX_PARENTS];
 190         struct clk_init_data init;
 191         int rc;
 192
 193         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 194         if (WARN_ON(!socfpga_clk))
 195                 return;
 196
 197         rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 198         if (rc)
 199                 clk_gate[0] = 0;
 200
 201         if (clk_gate[0]) {
 202                 socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
 203                 socfpga_clk->hw.bit_idx = clk_gate[1];
 204
 205                 gateclk_ops.enable = clk_gate_ops.enable;
 206                 gateclk_ops.disable = clk_gate_ops.disable;
 207         }
 208
 209         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 210         if (rc)
 211                 socfpga_clk->fixed_div = 0;
 212         else
 213                 socfpga_clk->fixed_div = fixed_div;
 214
 215         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 216         if (!rc) {
 217                 socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
 218                 socfpga_clk->shift = div_reg[1];
 219                 socfpga_clk->width = div_reg[2];
 220         } else {
 221                 socfpga_clk->div_reg = NULL;
 222         }
 223
 224         rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
 225         if (!rc) {
 226                 socfpga_clk->clk_phase[0] = clk_phase[0];
 227                 socfpga_clk->clk_phase[1] = clk_phase[1];
 228         }
 229
 230         of_property_read_string(node, "clock-output-names", &clk_name);
 231
 232         init.name = clk_name;
 233         init.ops = ops;
 234         init.flags = 0;
 235
 236         init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 237         init.parent_names = parent_name;
 238         socfpga_clk->hw.hw.init = &init;
 239
 240         clk = clk_register(NULL, &socfpga_clk->hw.hw);
 241         if (WARN_ON(IS_ERR(clk))) {
 242                 kfree(socfpga_clk);
 243                 return;
 244         }
 245         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 246         if (WARN_ON(rc))
 247                 return;
 248 }
 249
 250 void __init socfpga_gate_init(struct device_node *node)
 251 {
 252         __socfpga_gate_init(node, &gateclk_ops);
 253 }