drivers/clk/socfpga/clk-periph-a10.c

   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/of.h>
   9
  10 #include "clk.h"
  11
  12 #define CLK_MGR_FREE_SHIFT              16
  13 #define CLK_MGR_FREE_MASK               0x7
  14
  15 #define SOCFPGA_MPU_FREE_CLK            "mpu_free_clk"
  16 #define SOCFPGA_NOC_FREE_CLK            "noc_free_clk"
  17 #define SOCFPGA_SDMMC_FREE_CLK          "sdmmc_free_clk"
  18 #define to_socfpga_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw)
  19
  20 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
  21                                              unsigned long parent_rate)
  22 {
  23         struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
  24         u32 div;
  25
  26         if (socfpgaclk->fixed_div) {
  27                 div = socfpgaclk->fixed_div;
  28         } else if (socfpgaclk->div_reg) {
  29                 div = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  30                 div &= GENMASK(socfpgaclk->width - 1, 0);
  31                 div += 1;
  32         } else {
  33                 div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1);
  34         }
  35
  36         return parent_rate / div;
  37 }
  38
  39 static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
  40 {
  41         struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
  42         u32 clk_src;
  43         const char *name = clk_hw_get_name(hwclk);
  44
  45         clk_src = readl(socfpgaclk->hw.reg);
  46         if (streq(name, SOCFPGA_MPU_FREE_CLK) ||
  47             streq(name, SOCFPGA_NOC_FREE_CLK) ||
  48             streq(name, SOCFPGA_SDMMC_FREE_CLK))
  49                 return (clk_src >> CLK_MGR_FREE_SHIFT) &
  50                         CLK_MGR_FREE_MASK;
  51         else
  52                 return 0;
  53 }
  54
  55 static const struct clk_ops periclk_ops = {
  56         .recalc_rate = clk_periclk_recalc_rate,
  57         .get_parent = clk_periclk_get_parent,
  58 };
  59
  60 static __init void __socfpga_periph_init(struct device_node *node,
  61         const struct clk_ops *ops)
  62 {
  63         u32 reg;
  64         struct clk *clk;
  65         struct socfpga_periph_clk *periph_clk;
  66         const char *clk_name = node->name;
  67         const char *parent_name[SOCFPGA_MAX_PARENTS];
  68         struct clk_init_data init;
  69         int rc;
  70         u32 fixed_div;
  71         u32 div_reg[3];
  72
  73         of_property_read_u32(node, "reg", &reg);
  74
  75         periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
  76         if (WARN_ON(!periph_clk))
  77                 return;
  78
  79         periph_clk->hw.reg = clk_mgr_a10_base_addr + reg;
  80
  81         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
  82         if (!rc) {
  83                 periph_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
  84                 periph_clk->shift = div_reg[1];
  85                 periph_clk->width = div_reg[2];
  86         } else {
  87                 periph_clk->div_reg = NULL;
  88         }
  89
  90         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
  91         if (rc)
  92                 periph_clk->fixed_div = 0;
  93         else
  94                 periph_clk->fixed_div = fixed_div;
  95
  96         of_property_read_string(node, "clock-output-names", &clk_name);
  97
  98         init.name = clk_name;
  99         init.ops = ops;
 100         init.flags = 0;
 101
 102         init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 103         init.parent_names = parent_name;
 104
 105         periph_clk->hw.hw.init = &init;
 106
 107         clk = clk_register(NULL, &periph_clk->hw.hw);
 108         if (WARN_ON(IS_ERR(clk))) {
 109                 kfree(periph_clk);
 110                 return;
 111         }
 112         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 113         if (rc < 0) {
 114                 pr_err("Could not register clock provider for node:%s\n",
 115                        clk_name);
 116                 goto err_clk;
 117         }
 118
 119         return;
 120
 121 err_clk:
 122         clk_unregister(clk);
 123 }
 124
 125 void __init socfpga_a10_periph_init(struct device_node *node)
 126 {
 127         __socfpga_periph_init(node, &periclk_ops);
 128 }