drivers/clk/socfpga/clk-gate.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright 2011-2012 Calxeda, Inc.
   4  *  Copyright (C) 2012-2013 Altera Corporation <www.altera.com>
   5  *
   6  * Based from clk-highbank.c
   7  */
   8 #include <linux/slab.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/io.h>
  11 #include <linux/mfd/syscon.h>
  12 #include <linux/of.h>
  13 #include <linux/regmap.h>
  14
  15 #include "clk.h"
  16
  17 #define SOCFPGA_L4_MP_CLK               "l4_mp_clk"
  18 #define SOCFPGA_L4_SP_CLK               "l4_sp_clk"
  19 #define SOCFPGA_NAND_CLK                "nand_clk"
  20 #define SOCFPGA_NAND_X_CLK              "nand_x_clk"
  21 #define SOCFPGA_MMC_CLK                 "sdmmc_clk"
  22 #define SOCFPGA_GPIO_DB_CLK_OFFSET      0xA8
  23
  24 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  25
  26 /* SDMMC Group for System Manager defines */
  27 #define SYSMGR_SDMMCGRP_CTRL_OFFSET    0x108
  28
  29 static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
  30 {
  31         u32 l4_src;
  32         u32 perpll_src;
  33         const char *name = clk_hw_get_name(hwclk);
  34
  35         if (streq(name, SOCFPGA_L4_MP_CLK)) {
  36                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  37                 return l4_src & 0x1;
  38         }
  39         if (streq(name, SOCFPGA_L4_SP_CLK)) {
  40                 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  41                 return !!(l4_src & 2);
  42         }
  43
  44         perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  45         if (streq(name, SOCFPGA_MMC_CLK))
  46                 return perpll_src & 0x3;
  47         if (streq(name, SOCFPGA_NAND_CLK) ||
  48             streq(name, SOCFPGA_NAND_X_CLK))
  49                 return (perpll_src >> 2) & 3;
  50
  51         /* QSPI clock */
  52         return (perpll_src >> 4) & 3;
  53
  54 }
  55
  56 static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
  57 {
  58         u32 src_reg;
  59         const char *name = clk_hw_get_name(hwclk);
  60
  61         if (streq(name, SOCFPGA_L4_MP_CLK)) {
  62                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  63                 src_reg &= ~0x1;
  64                 src_reg |= parent;
  65                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  66         } else if (streq(name, SOCFPGA_L4_SP_CLK)) {
  67                 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
  68                 src_reg &= ~0x2;
  69                 src_reg |= (parent << 1);
  70                 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
  71         } else {
  72                 src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  73                 if (streq(name, SOCFPGA_MMC_CLK)) {
  74                         src_reg &= ~0x3;
  75                         src_reg |= parent;
  76                 } else if (streq(name, SOCFPGA_NAND_CLK) ||
  77                         streq(name, SOCFPGA_NAND_X_CLK)) {
  78                         src_reg &= ~0xC;
  79                         src_reg |= (parent << 2);
  80                 } else {/* QSPI clock */
  81                         src_reg &= ~0x30;
  82                         src_reg |= (parent << 4);
  83                 }
  84                 writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
  85         }
  86
  87         return 0;
  88 }
  89
  90 static u32 socfpga_clk_get_div(struct socfpga_gate_clk *socfpgaclk)
  91 {
  92         u32 div = 1, val;
  93
  94         if (socfpgaclk->fixed_div)
  95                 div = socfpgaclk->fixed_div;
  96         else if (socfpgaclk->div_reg) {
  97                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  98                 val &= GENMASK(socfpgaclk->width - 1, 0);
  99                 /* Check for GPIO_DB_CLK by its offset */
 100                 if ((uintptr_t) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
 101                         div = val + 1;
 102                 else
 103                         div = (1 << val);
 104         }
 105
 106         return div;
 107 }
 108
 109 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
 110                                              unsigned long parent_rate)
 111 {
 112         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 113         u32 div = socfpga_clk_get_div(socfpgaclk);
 114
 115         return parent_rate / div;
 116 }
 117
 118
 119 static int socfpga_clk_determine_rate(struct clk_hw *hwclk,
 120                                       struct clk_rate_request *req)
 121 {
 122         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
 123         u32 div = socfpga_clk_get_div(socfpgaclk);
 124
 125         req->rate = req->best_parent_rate / div;
 126
 127         return 0;
 128 }
 129
 130 static struct clk_ops gateclk_ops = {
 131         .recalc_rate = socfpga_clk_recalc_rate,
 132         .determine_rate = socfpga_clk_determine_rate,
 133         .get_parent = socfpga_clk_get_parent,
 134         .set_parent = socfpga_clk_set_parent,
 135 };
 136
 137 void __init socfpga_gate_init(struct device_node *node)
 138 {
 139         u32 clk_gate[2];
 140         u32 div_reg[3];
 141         u32 fixed_div;
 142         struct clk_hw *hw_clk;
 143         struct socfpga_gate_clk *socfpga_clk;
 144         const char *clk_name = node->name;
 145         const char *parent_name[SOCFPGA_MAX_PARENTS];
 146         struct clk_init_data init;
 147         struct clk_ops *ops;
 148         int rc;
 149
 150         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 151         if (WARN_ON(!socfpga_clk))
 152                 return;
 153
 154         ops = kmemdup(&gateclk_ops, sizeof(gateclk_ops), GFP_KERNEL);
 155         if (WARN_ON(!ops))
 156                 goto err_kmemdup;
 157
 158         rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 159         if (rc)
 160                 clk_gate[0] = 0;
 161
 162         if (clk_gate[0]) {
 163                 socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
 164                 socfpga_clk->hw.bit_idx = clk_gate[1];
 165
 166                 ops->enable = clk_gate_ops.enable;
 167                 ops->disable = clk_gate_ops.disable;
 168         }
 169
 170         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 171         if (rc)
 172                 socfpga_clk->fixed_div = 0;
 173         else
 174                 socfpga_clk->fixed_div = fixed_div;
 175
 176         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 177         if (!rc) {
 178                 socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
 179                 socfpga_clk->shift = div_reg[1];
 180                 socfpga_clk->width = div_reg[2];
 181         } else {
 182                 socfpga_clk->div_reg = NULL;
 183         }
 184
 185         of_property_read_string(node, "clock-output-names", &clk_name);
 186
 187         init.name = clk_name;
 188         init.ops = ops;
 189         init.flags = 0;
 190
 191         init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 192         if (init.num_parents < 2) {
 193                 ops->get_parent = NULL;
 194                 ops->set_parent = NULL;
 195         }
 196
 197         init.parent_names = parent_name;
 198         socfpga_clk->hw.hw.init = &init;
 199
 200         hw_clk = &socfpga_clk->hw.hw;
 201
 202         rc = clk_hw_register(NULL, hw_clk);
 203         if (rc) {
 204                 pr_err("Could not register clock:%s\n", clk_name);
 205                 goto err_clk_hw_register;
 206         }
 207
 208         rc = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw_clk);
 209         if (rc) {
 210                 pr_err("Could not register clock provider for node:%s\n",
 211                        clk_name);
 212                 goto err_of_clk_add_hw_provider;
 213         }
 214
 215         return;
 216
 217 err_of_clk_add_hw_provider:
 218         clk_hw_unregister(hw_clk);
 219 err_clk_hw_register:
 220         kfree(ops);
 221 err_kmemdup:
 222         kfree(socfpga_clk);
 223 }