linux/drivers/clk/socfpga/clk-gate-a10.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2015 Altera Corporation. All rights reserved
   4 */
   5#include <linux/slab.h>
   6#include <linux/clk-provider.h>
   7#include <linux/io.h>
   8#include <linux/mfd/syscon.h>
   9#include <linux/of.h>
  10#include <linux/regmap.h>
  11
  12#include "clk.h"
  13
  14#define streq(a, b) (strcmp((a), (b)) == 0)
  15
  16#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  17
  18/* SDMMC Group for System Manager defines */
  19#define SYSMGR_SDMMCGRP_CTRL_OFFSET     0x28
  20
  21static unsigned long socfpga_gate_clk_recalc_rate(struct clk_hw *hwclk,
  22        unsigned long parent_rate)
  23{
  24        struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  25        u32 div = 1, val;
  26
  27        if (socfpgaclk->fixed_div)
  28                div = socfpgaclk->fixed_div;
  29        else if (socfpgaclk->div_reg) {
  30                val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  31                val &= GENMASK(socfpgaclk->width - 1, 0);
  32                div = (1 << val);
  33        }
  34
  35        return parent_rate / div;
  36}
  37
  38static int socfpga_clk_prepare(struct clk_hw *hwclk)
  39{
  40        struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  41        int i;
  42        u32 hs_timing;
  43        u32 clk_phase[2];
  44
  45        if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
  46                for (i = 0; i < ARRAY_SIZE(clk_phase); i++) {
  47                        switch (socfpgaclk->clk_phase[i]) {
  48                        case 0:
  49                                clk_phase[i] = 0;
  50                                break;
  51                        case 45:
  52                                clk_phase[i] = 1;
  53                                break;
  54                        case 90:
  55                                clk_phase[i] = 2;
  56                                break;
  57                        case 135:
  58                                clk_phase[i] = 3;
  59                                break;
  60                        case 180:
  61                                clk_phase[i] = 4;
  62                                break;
  63                        case 225:
  64                                clk_phase[i] = 5;
  65                                break;
  66                        case 270:
  67                                clk_phase[i] = 6;
  68                                break;
  69                        case 315:
  70                                clk_phase[i] = 7;
  71                                break;
  72                        default:
  73                                clk_phase[i] = 0;
  74                                break;
  75                        }
  76                }
  77
  78                hs_timing = SYSMGR_SDMMC_CTRL_SET_AS10(clk_phase[0], clk_phase[1]);
  79                if (!IS_ERR(socfpgaclk->sys_mgr_base_addr))
  80                        regmap_write(socfpgaclk->sys_mgr_base_addr,
  81                                     SYSMGR_SDMMCGRP_CTRL_OFFSET, hs_timing);
  82                else
  83                        pr_err("%s: cannot set clk_phase because sys_mgr_base_addr is not available!\n",
  84                                        __func__);
  85        }
  86        return 0;
  87}
  88
  89static struct clk_ops gateclk_ops = {
  90        .prepare = socfpga_clk_prepare,
  91        .recalc_rate = socfpga_gate_clk_recalc_rate,
  92};
  93
  94static void __init __socfpga_gate_init(struct device_node *node,
  95        const struct clk_ops *ops)
  96{
  97        u32 clk_gate[2];
  98        u32 div_reg[3];
  99        u32 clk_phase[2];
 100        u32 fixed_div;
 101        struct clk_hw *hw_clk;
 102        struct socfpga_gate_clk *socfpga_clk;
 103        const char *clk_name = node->name;
 104        const char *parent_name[SOCFPGA_MAX_PARENTS];
 105        struct clk_init_data init;
 106        int rc;
 107
 108        socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 109        if (WARN_ON(!socfpga_clk))
 110                return;
 111
 112        rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 113        if (rc)
 114                clk_gate[0] = 0;
 115
 116        if (clk_gate[0]) {
 117                socfpga_clk->hw.reg = clk_mgr_a10_base_addr + clk_gate[0];
 118                socfpga_clk->hw.bit_idx = clk_gate[1];
 119
 120                gateclk_ops.enable = clk_gate_ops.enable;
 121                gateclk_ops.disable = clk_gate_ops.disable;
 122        }
 123
 124        rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 125        if (rc)
 126                socfpga_clk->fixed_div = 0;
 127        else
 128                socfpga_clk->fixed_div = fixed_div;
 129
 130        rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 131        if (!rc) {
 132                socfpga_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
 133                socfpga_clk->shift = div_reg[1];
 134                socfpga_clk->width = div_reg[2];
 135        } else {
 136                socfpga_clk->div_reg = NULL;
 137        }
 138
 139        rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
 140        if (!rc) {
 141                socfpga_clk->clk_phase[0] = clk_phase[0];
 142                socfpga_clk->clk_phase[1] = clk_phase[1];
 143
 144                socfpga_clk->sys_mgr_base_addr =
 145                        syscon_regmap_lookup_by_compatible("altr,sys-mgr");
 146                if (IS_ERR(socfpga_clk->sys_mgr_base_addr)) {
 147                        pr_err("%s: failed to find altr,sys-mgr regmap!\n",
 148                                        __func__);
 149                        kfree(socfpga_clk);
 150                        return;
 151                }
 152        }
 153
 154        of_property_read_string(node, "clock-output-names", &clk_name);
 155
 156        init.name = clk_name;
 157        init.ops = ops;
 158        init.flags = 0;
 159
 160        init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 161        init.parent_names = parent_name;
 162        socfpga_clk->hw.hw.init = &init;
 163        hw_clk = &socfpga_clk->hw.hw;
 164
 165        if (clk_hw_register(NULL, hw_clk)) {
 166                kfree(socfpga_clk);
 167                return;
 168        }
 169        rc = of_clk_add_provider(node, of_clk_src_simple_get, hw_clk);
 170        if (WARN_ON(rc))
 171                return;
 172}
 173
 174void __init socfpga_a10_gate_init(struct device_node *node)
 175{
 176        __socfpga_gate_init(node, &gateclk_ops);
 177}
 178