linux/drivers/clk/socfpga/clk-periph-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/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
  20static 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
  39static 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
  55static const struct clk_ops periclk_ops = {
  56        .recalc_rate = clk_periclk_recalc_rate,
  57        .get_parent = clk_periclk_get_parent,
  58};
  59
  60static __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
 121err_clk:
 122        clk_unregister(clk);
 123}
 124
 125void __init socfpga_a10_periph_init(struct device_node *node)
 126{
 127        __socfpga_periph_init(node, &periclk_ops);
 128}
 129