kernel/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 streq(a, b) (strcmp((a), (b)) == 0)
  36
  37 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  38
  39 /* SDMMC Group for System Manager defines */
  40 #define SYSMGR_SDMMCGRP_CTRL_OFFSET    0x108
  41 #define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel) \
  42         ((((smplsel) & 0x7) << 3) | (((drvsel) & 0x7) << 0))
  43
  44 static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
  45 {
  46         u32 l4_src;
  47         u32 perpll_src;
  48
  49         if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
  50                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  51                 return l4_src &= 0x1;
  52         }
  53         if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
  54                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  55                 return !!(l4_src & 2);
  56         }
  57
  58         perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  59         if (streq(hwclk->init->name, SOCFPGA_MMC_CLK))
  60                 return perpll_src &= 0x3;
  61         if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
  62                         streq(hwclk->init->name, SOCFPGA_NAND_X_CLK))
  63                         return (perpll_src >> 2) & 3;
  64
  65         /* QSPI clock */
  66         return (perpll_src >> 4) & 3;
  67
  68 }
  69
  70 static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
  71 {
  72         u32 src_reg;
  73
  74         if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
  75                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  76                 src_reg &= ~0x1;
  77                 src_reg |= parent;
  78                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  79         } else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
  80                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  81                 src_reg &= ~0x2;
  82                 src_reg |= (parent << 1);
  83                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  84         } else {
  85                 src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  86                 if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) {
  87                         src_reg &= ~0x3;
  88                         src_reg |= parent;
  89                 } else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
  90                         streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) {
  91                         src_reg &= ~0xC;
  92                         src_reg |= (parent << 2);
  93                 } else {/* QSPI clock */
  94                         src_reg &= ~0x30;
  95                         src_reg |= (parent << 4);
  96                 }
  97                 writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  98         }
  99
 100         return 0;
 101 }
 102
 103 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
 104         unsigned long parent_rate)
 105 {
 106         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 107         u32 div = 1, val;
 108
 109         if (socfpgaclk->fixed_div)
 110                 div = socfpgaclk->fixed_div;
 111         else if (socfpgaclk->div_reg) {
 112                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
 113                 val &= div_mask(socfpgaclk->width);
 114                 /* Check for GPIO_DB_CLK by its offset */
 115                 if ((int) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
 116                         div = val + 1;
 117                 else
 118                         div = (1 << val);
 119         }
 120
 121         return parent_rate / div;
 122 }
 123
 124 static int socfpga_clk_prepare(struct clk_hw *hwclk)
 125 {
 126         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 127         struct regmap *sys_mgr_base_addr;
 128         int i;
 129         u32 hs_timing;
 130         u32 clk_phase[2];
 131
 132         if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
 133                 sys_mgr_base_addr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
 134                 if (IS_ERR(sys_mgr_base_addr)) {
 135                         pr_err("%s: failed to find altr,sys-mgr regmap!\n", __func__);
 136                         return -EINVAL;
 137                 }
 138
 139                 for (i = 0; i < 2; i++) {
 140                         switch (socfpgaclk->clk_phase[i]) {
 141                         case 0:
 142                                 clk_phase[i] = 0;
 143                                 break;
 144                         case 45:
 145                                 clk_phase[i] = 1;
 146                                 break;
 147                         case 90:
 148                                 clk_phase[i] = 2;
 149                                 break;
 150                         case 135:
 151                                 clk_phase[i] = 3;
 152                                 break;
 153                         case 180:
 154                                 clk_phase[i] = 4;
 155                                 break;
 156                         case 225:
 157                                 clk_phase[i] = 5;
 158                                 break;
 159                         case 270:
 160                                 clk_phase[i] = 6;
 161                                 break;
 162                         case 315:
 163                                 clk_phase[i] = 7;
 164                                 break;
 165                         default:
 166                                 clk_phase[i] = 0;
 167                                 break;
 168                         }
 169                 }
 170                 hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
 171                 regmap_write(sys_mgr_base_addr, SYSMGR_SDMMCGRP_CTRL_OFFSET,
 172                         hs_timing);
 173         }
 174         return 0;
 175 }
 176
 177 static struct clk_ops gateclk_ops = {
 178         .prepare = socfpga_clk_prepare,
 179         .recalc_rate = socfpga_clk_recalc_rate,
 180         .get_parent = socfpga_clk_get_parent,
 181         .set_parent = socfpga_clk_set_parent,
 182 };
 183
 184 static void __init __socfpga_gate_init(struct device_node *node,
 185         const struct clk_ops *ops)
 186 {
 187         u32 clk_gate[2];
 188         u32 div_reg[3];
 189         u32 clk_phase[2];
 190         u32 fixed_div;
 191         struct clk *clk;
 192         struct socfpga_gate_clk *socfpga_clk;
 193         const char *clk_name = node->name;
 194         const char *parent_name[SOCFPGA_MAX_PARENTS];
 195         struct clk_init_data init;
 196         int rc;
 197         int i = 0;
 198
 199         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 200         if (WARN_ON(!socfpga_clk))
 201                 return;
 202
 203         rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 204         if (rc)
 205                 clk_gate[0] = 0;
 206
 207         if (clk_gate[0]) {
 208                 socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
 209                 socfpga_clk->hw.bit_idx = clk_gate[1];
 210
 211                 gateclk_ops.enable = clk_gate_ops.enable;
 212                 gateclk_ops.disable = clk_gate_ops.disable;
 213         }
 214
 215         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 216         if (rc)
 217                 socfpga_clk->fixed_div = 0;
 218         else
 219                 socfpga_clk->fixed_div = fixed_div;
 220
 221         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 222         if (!rc) {
 223                 socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
 224                 socfpga_clk->shift = div_reg[1];
 225                 socfpga_clk->width = div_reg[2];
 226         } else {
 227                 socfpga_clk->div_reg = 0;
 228         }
 229
 230         rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
 231         if (!rc) {
 232                 socfpga_clk->clk_phase[0] = clk_phase[0];
 233                 socfpga_clk->clk_phase[1] = clk_phase[1];
 234         }
 235
 236         of_property_read_string(node, "clock-output-names", &clk_name);
 237
 238         init.name = clk_name;
 239         init.ops = ops;
 240         init.flags = 0;
 241         while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] =
 242                         of_clk_get_parent_name(node, i)) != NULL)
 243                 i++;
 244
 245         init.parent_names = parent_name;
 246         init.num_parents = i;
 247         socfpga_clk->hw.hw.init = &init;
 248
 249         clk = clk_register(NULL, &socfpga_clk->hw.hw);
 250         if (WARN_ON(IS_ERR(clk))) {
 251                 kfree(socfpga_clk);
 252                 return;
 253         }
 254         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 255         if (WARN_ON(rc))
 256                 return;
 257 }
 258
 259 void __init socfpga_gate_init(struct device_node *node)
 260 {
 261         __socfpga_gate_init(node, &gateclk_ops);
 262 }