drivers/clk/mvebu/common.c

   1 /*
   2  * Marvell EBU SoC common clock handling
   3  *
   4  * Copyright (C) 2012 Marvell
   5  *
   6  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   7  * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
   8  * Andrew Lunn <andrew@lunn.ch>
   9  *
  10  * This file is licensed under the terms of the GNU General Public
  11  * License version 2.  This program is licensed "as is" without any
  12  * warranty of any kind, whether express or implied.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/clk.h>
  17 #include <linux/clkdev.h>
  18 #include <linux/clk-provider.h>
  19 #include <linux/io.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22
  23 #include "common.h"
  24
  25 /*
  26  * Core Clocks
  27  */
  28
  29 static struct clk_onecell_data clk_data;
  30
  31 void __init mvebu_coreclk_setup(struct device_node *np,
  32                                 const struct coreclk_soc_desc *desc)
  33 {
  34         const char *tclk_name = "tclk";
  35         const char *cpuclk_name = "cpuclk";
  36         void __iomem *base;
  37         unsigned long rate;
  38         int n;
  39
  40         base = of_iomap(np, 0);
  41         if (WARN_ON(!base))
  42                 return;
  43
  44         /* Allocate struct for TCLK, cpu clk, and core ratio clocks */
  45         clk_data.clk_num = 2 + desc->num_ratios;
  46         clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *),
  47                                 GFP_KERNEL);
  48         if (WARN_ON(!clk_data.clks)) {
  49                 iounmap(base);
  50                 return;
  51         }
  52
  53         /* Register TCLK */
  54         of_property_read_string_index(np, "clock-output-names", 0,
  55                                       &tclk_name);
  56         rate = desc->get_tclk_freq(base);
  57         clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL,
  58                                                    CLK_IS_ROOT, rate);
  59         WARN_ON(IS_ERR(clk_data.clks[0]));
  60
  61         /* Register CPU clock */
  62         of_property_read_string_index(np, "clock-output-names", 1,
  63                                       &cpuclk_name);
  64         rate = desc->get_cpu_freq(base);
  65         clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL,
  66                                                    CLK_IS_ROOT, rate);
  67         WARN_ON(IS_ERR(clk_data.clks[1]));
  68
  69         /* Register fixed-factor clocks derived from CPU clock */
  70         for (n = 0; n < desc->num_ratios; n++) {
  71                 const char *rclk_name = desc->ratios[n].name;
  72                 int mult, div;
  73
  74                 of_property_read_string_index(np, "clock-output-names",
  75                                               2+n, &rclk_name);
  76                 desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div);
  77                 clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name,
  78                                        cpuclk_name, 0, mult, div);
  79                 WARN_ON(IS_ERR(clk_data.clks[2+n]));
  80         };
  81
  82         /* SAR register isn't needed anymore */
  83         iounmap(base);
  84
  85         of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
  86 }
  87
  88 /*
  89  * Clock Gating Control
  90  */
  91
  92 DEFINE_SPINLOCK(ctrl_gating_lock);
  93
  94 struct clk_gating_ctrl {
  95         spinlock_t *lock;
  96         struct clk **gates;
  97         int num_gates;
  98 };
  99
 100 #define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
 101
 102 static struct clk *clk_gating_get_src(
 103         struct of_phandle_args *clkspec, void *data)
 104 {
 105         struct clk_gating_ctrl *ctrl = (struct clk_gating_ctrl *)data;
 106         int n;
 107
 108         if (clkspec->args_count < 1)
 109                 return ERR_PTR(-EINVAL);
 110
 111         for (n = 0; n < ctrl->num_gates; n++) {
 112                 struct clk_gate *gate =
 113                         to_clk_gate(__clk_get_hw(ctrl->gates[n]));
 114                 if (clkspec->args[0] == gate->bit_idx)
 115                         return ctrl->gates[n];
 116         }
 117         return ERR_PTR(-ENODEV);
 118 }
 119
 120 void __init mvebu_clk_gating_setup(struct device_node *np,
 121                                    const struct clk_gating_soc_desc *desc)
 122 {
 123         struct clk_gating_ctrl *ctrl;
 124         struct clk *clk;
 125         void __iomem *base;
 126         const char *default_parent = NULL;
 127         int n;
 128
 129         base = of_iomap(np, 0);
 130         if (WARN_ON(!base))
 131                 return;
 132
 133         clk = of_clk_get(np, 0);
 134         if (!IS_ERR(clk)) {
 135                 default_parent = __clk_get_name(clk);
 136                 clk_put(clk);
 137         }
 138
 139         ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 140         if (WARN_ON(!ctrl))
 141                 goto ctrl_out;
 142
 143         /* lock must already be initialized */
 144         ctrl->lock = &ctrl_gating_lock;
 145
 146         /* Count, allocate, and register clock gates */
 147         for (n = 0; desc[n].name;)
 148                 n++;
 149
 150         ctrl->num_gates = n;
 151         ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *),
 152                               GFP_KERNEL);
 153         if (WARN_ON(!ctrl->gates))
 154                 goto gates_out;
 155
 156         for (n = 0; n < ctrl->num_gates; n++) {
 157                 const char *parent =
 158                         (desc[n].parent) ? desc[n].parent : default_parent;
 159                 ctrl->gates[n] = clk_register_gate(NULL, desc[n].name, parent,
 160                                         desc[n].flags, base, desc[n].bit_idx,
 161                                         0, ctrl->lock);
 162                 WARN_ON(IS_ERR(ctrl->gates[n]));
 163         }
 164
 165         of_clk_add_provider(np, clk_gating_get_src, ctrl);
 166
 167         return;
 168 gates_out:
 169         kfree(ctrl);
 170 ctrl_out:
 171         iounmap(base);
 172 }