linux/drivers/clk/socfpga/clk-gate.c
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   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
  39static 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
  65static 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
  98static 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
 119static 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
 172static 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
 179static 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
 250void __init socfpga_gate_init(struct device_node *node)
 251{
 252        __socfpga_gate_init(node, &gateclk_ops);
 253}
 254