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/clk.h>
  19 #include <linux/clkdev.h>
  20 #include <linux/clk-provider.h>
  21 #include <linux/io.h>
  22 #include <linux/mfd/syscon.h>
  23 #include <linux/of.h>
  24 #include <linux/regmap.h>
  25
  26 #include "clk.h"
  27
  28 #define SOCFPGA_L4_MP_CLK               "l4_mp_clk"
  29 #define SOCFPGA_L4_SP_CLK               "l4_sp_clk"
  30 #define SOCFPGA_NAND_CLK                "nand_clk"
  31 #define SOCFPGA_NAND_X_CLK              "nand_x_clk"
  32 #define SOCFPGA_MMC_CLK                 "sdmmc_clk"
  33 #define SOCFPGA_GPIO_DB_CLK_OFFSET      0xA8
  34
  35 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  36
  37 /* SDMMC Group for System Manager defines */
  38 #define SYSMGR_SDMMCGRP_CTRL_OFFSET    0x108
  39
  40 static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
  41 {
  42         u32 l4_src;
  43         u32 perpll_src;
  44
  45         if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
  46                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  47                 return l4_src &= 0x1;
  48         }
  49         if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
  50                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  51                 return !!(l4_src & 2);
  52         }
  53
  54         perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  55         if (streq(hwclk->init->name, SOCFPGA_MMC_CLK))
  56                 return perpll_src &= 0x3;
  57         if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
  58                         streq(hwclk->init->name, SOCFPGA_NAND_X_CLK))
  59                         return (perpll_src >> 2) & 3;
  60
  61         /* QSPI clock */
  62         return (perpll_src >> 4) & 3;
  63
  64 }
  65
  66 static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
  67 {
  68         u32 src_reg;
  69
  70         if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
  71                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  72                 src_reg &= ~0x1;
  73                 src_reg |= parent;
  74                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  75         } else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
  76                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  77                 src_reg &= ~0x2;
  78                 src_reg |= (parent << 1);
  79                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  80         } else {
  81                 src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  82                 if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) {
  83                         src_reg &= ~0x3;
  84                         src_reg |= parent;
  85                 } else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
  86                         streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) {
  87                         src_reg &= ~0xC;
  88                         src_reg |= (parent << 2);
  89                 } else {/* QSPI clock */
  90                         src_reg &= ~0x30;
  91                         src_reg |= (parent << 4);
  92                 }
  93                 writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  94         }
  95
  96         return 0;
  97 }
  98
  99 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
 100         unsigned long parent_rate)
 101 {
 102         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 103         u32 div = 1, val;
 104
 105         if (socfpgaclk->fixed_div)
 106                 div = socfpgaclk->fixed_div;
 107         else if (socfpgaclk->div_reg) {
 108                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
 109                 val &= div_mask(socfpgaclk->width);
 110                 /* Check for GPIO_DB_CLK by its offset */
 111                 if ((int) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
 112                         div = val + 1;
 113                 else
 114                         div = (1 << val);
 115         }
 116
 117         return parent_rate / div;
 118 }
 119
 120 static int socfpga_clk_prepare(struct clk_hw *hwclk)
 121 {
 122         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 123         struct regmap *sys_mgr_base_addr;
 124         int i;
 125         u32 hs_timing;
 126         u32 clk_phase[2];
 127
 128         if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
 129                 sys_mgr_base_addr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
 130                 if (IS_ERR(sys_mgr_base_addr)) {
 131                         pr_err("%s: failed to find altr,sys-mgr regmap!\n", __func__);
 132                         return -EINVAL;
 133                 }
 134
 135                 for (i = 0; i < 2; i++) {
 136                         switch (socfpgaclk->clk_phase[i]) {
 137                         case 0:
 138                                 clk_phase[i] = 0;
 139                                 break;
 140                         case 45:
 141                                 clk_phase[i] = 1;
 142                                 break;
 143                         case 90:
 144                                 clk_phase[i] = 2;
 145                                 break;
 146                         case 135:
 147                                 clk_phase[i] = 3;
 148                                 break;
 149                         case 180:
 150                                 clk_phase[i] = 4;
 151                                 break;
 152                         case 225:
 153                                 clk_phase[i] = 5;
 154                                 break;
 155                         case 270:
 156                                 clk_phase[i] = 6;
 157                                 break;
 158                         case 315:
 159                                 clk_phase[i] = 7;
 160                                 break;
 161                         default:
 162                                 clk_phase[i] = 0;
 163                                 break;
 164                         }
 165                 }
 166                 hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
 167                 regmap_write(sys_mgr_base_addr, SYSMGR_SDMMCGRP_CTRL_OFFSET,
 168                         hs_timing);
 169         }
 170         return 0;
 171 }
 172
 173 static struct clk_ops gateclk_ops = {
 174         .prepare = socfpga_clk_prepare,
 175         .recalc_rate = socfpga_clk_recalc_rate,
 176         .get_parent = socfpga_clk_get_parent,
 177         .set_parent = socfpga_clk_set_parent,
 178 };
 179
 180 static void __init __socfpga_gate_init(struct device_node *node,
 181         const struct clk_ops *ops)
 182 {
 183         u32 clk_gate[2];
 184         u32 div_reg[3];
 185         u32 clk_phase[2];
 186         u32 fixed_div;
 187         struct clk *clk;
 188         struct socfpga_gate_clk *socfpga_clk;
 189         const char *clk_name = node->name;
 190         const char *parent_name[SOCFPGA_MAX_PARENTS];
 191         struct clk_init_data init;
 192         int rc;
 193
 194         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 195         if (WARN_ON(!socfpga_clk))
 196                 return;
 197
 198         rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 199         if (rc)
 200                 clk_gate[0] = 0;
 201
 202         if (clk_gate[0]) {
 203                 socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
 204                 socfpga_clk->hw.bit_idx = clk_gate[1];
 205
 206                 gateclk_ops.enable = clk_gate_ops.enable;
 207                 gateclk_ops.disable = clk_gate_ops.disable;
 208         }
 209
 210         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 211         if (rc)
 212                 socfpga_clk->fixed_div = 0;
 213         else
 214                 socfpga_clk->fixed_div = fixed_div;
 215
 216         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 217         if (!rc) {
 218                 socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
 219                 socfpga_clk->shift = div_reg[1];
 220                 socfpga_clk->width = div_reg[2];
 221         } else {
 222                 socfpga_clk->div_reg = NULL;
 223         }
 224
 225         rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
 226         if (!rc) {
 227                 socfpga_clk->clk_phase[0] = clk_phase[0];
 228                 socfpga_clk->clk_phase[1] = clk_phase[1];
 229         }
 230
 231         of_property_read_string(node, "clock-output-names", &clk_name);
 232
 233         init.name = clk_name;
 234         init.ops = ops;
 235         init.flags = 0;
 236
 237         init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 238         init.parent_names = parent_name;
 239         socfpga_clk->hw.hw.init = &init;
 240
 241         clk = clk_register(NULL, &socfpga_clk->hw.hw);
 242         if (WARN_ON(IS_ERR(clk))) {
 243                 kfree(socfpga_clk);
 244                 return;
 245         }
 246         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 247         if (WARN_ON(rc))
 248                 return;
 249 }
 250
 251 void __init socfpga_gate_init(struct device_node *node)
 252 {
 253         __socfpga_gate_init(node, &gateclk_ops);
 254 }