drivers/clk/clk-lan966x.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Microchip LAN966x SoC Clock driver.
   4  *
   5  * Copyright (C) 2021 Microchip Technology, Inc. and its subsidiaries
   6  *
   7  * Author: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
   8  */
   9
  10 #include <linux/bitfield.h>
  11 #include <linux/clk-provider.h>
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18
  19 #include <dt-bindings/clock/microchip,lan966x.h>
  20
  21 #define GCK_ENA         BIT(0)
  22 #define GCK_SRC_SEL     GENMASK(9, 8)
  23 #define GCK_PRESCALER   GENMASK(23, 16)
  24
  25 #define DIV_MAX         255
  26
  27 static const char *clk_names[N_CLOCKS] = {
  28         "qspi0", "qspi1", "qspi2", "sdmmc0",
  29         "pi", "mcan0", "mcan1", "flexcom0",
  30         "flexcom1", "flexcom2", "flexcom3",
  31         "flexcom4", "timer1", "usb_refclk",
  32 };
  33
  34 struct lan966x_gck {
  35         struct clk_hw hw;
  36         void __iomem *reg;
  37 };
  38 #define to_lan966x_gck(hw) container_of(hw, struct lan966x_gck, hw)
  39
  40 static const struct clk_parent_data lan966x_gck_pdata[] = {
  41         { .fw_name = "cpu", },
  42         { .fw_name = "ddr", },
  43         { .fw_name = "sys", },
  44 };
  45
  46 static struct clk_init_data init = {
  47         .parent_data = lan966x_gck_pdata,
  48         .num_parents = ARRAY_SIZE(lan966x_gck_pdata),
  49 };
  50
  51 struct clk_gate_soc_desc {
  52         const char *name;
  53         int bit_idx;
  54 };
  55
  56 static const struct clk_gate_soc_desc clk_gate_desc[] = {
  57         { "uhphs", 11 },
  58         { "udphs", 10 },
  59         { "mcramc", 9 },
  60         { "hmatrix", 8 },
  61         { }
  62 };
  63
  64 static DEFINE_SPINLOCK(clk_gate_lock);
  65 static void __iomem *base;
  66
  67 static int lan966x_gck_enable(struct clk_hw *hw)
  68 {
  69         struct lan966x_gck *gck = to_lan966x_gck(hw);
  70         u32 val = readl(gck->reg);
  71
  72         val |= GCK_ENA;
  73         writel(val, gck->reg);
  74
  75         return 0;
  76 }
  77
  78 static void lan966x_gck_disable(struct clk_hw *hw)
  79 {
  80         struct lan966x_gck *gck = to_lan966x_gck(hw);
  81         u32 val = readl(gck->reg);
  82
  83         val &= ~GCK_ENA;
  84         writel(val, gck->reg);
  85 }
  86
  87 static int lan966x_gck_set_rate(struct clk_hw *hw,
  88                                 unsigned long rate,
  89                                 unsigned long parent_rate)
  90 {
  91         struct lan966x_gck *gck = to_lan966x_gck(hw);
  92         u32 div, val = readl(gck->reg);
  93
  94         if (rate == 0 || parent_rate == 0)
  95                 return -EINVAL;
  96
  97         /* Set Prescalar */
  98         div = parent_rate / rate;
  99         val &= ~GCK_PRESCALER;
 100         val |= FIELD_PREP(GCK_PRESCALER, (div - 1));
 101         writel(val, gck->reg);
 102
 103         return 0;
 104 }
 105
 106 static unsigned long lan966x_gck_recalc_rate(struct clk_hw *hw,
 107                                              unsigned long parent_rate)
 108 {
 109         struct lan966x_gck *gck = to_lan966x_gck(hw);
 110         u32 div, val = readl(gck->reg);
 111
 112         div = FIELD_GET(GCK_PRESCALER, val);
 113
 114         return parent_rate / (div + 1);
 115 }
 116
 117 static int lan966x_gck_determine_rate(struct clk_hw *hw,
 118                                       struct clk_rate_request *req)
 119 {
 120         struct clk_hw *parent;
 121         int i;
 122
 123         for (i = 0; i < clk_hw_get_num_parents(hw); ++i) {
 124                 parent = clk_hw_get_parent_by_index(hw, i);
 125                 if (!parent)
 126                         continue;
 127
 128                 /* Allowed prescaler divider range is 0-255 */
 129                 if (clk_hw_get_rate(parent) / req->rate <= DIV_MAX) {
 130                         req->best_parent_hw = parent;
 131                         req->best_parent_rate = clk_hw_get_rate(parent);
 132
 133                         return 0;
 134                 }
 135         }
 136
 137         return -EINVAL;
 138 }
 139
 140 static u8 lan966x_gck_get_parent(struct clk_hw *hw)
 141 {
 142         struct lan966x_gck *gck = to_lan966x_gck(hw);
 143         u32 val = readl(gck->reg);
 144
 145         return FIELD_GET(GCK_SRC_SEL, val);
 146 }
 147
 148 static int lan966x_gck_set_parent(struct clk_hw *hw, u8 index)
 149 {
 150         struct lan966x_gck *gck = to_lan966x_gck(hw);
 151         u32 val = readl(gck->reg);
 152
 153         val &= ~GCK_SRC_SEL;
 154         val |= FIELD_PREP(GCK_SRC_SEL, index);
 155         writel(val, gck->reg);
 156
 157         return 0;
 158 }
 159
 160 static const struct clk_ops lan966x_gck_ops = {
 161         .enable         = lan966x_gck_enable,
 162         .disable        = lan966x_gck_disable,
 163         .set_rate       = lan966x_gck_set_rate,
 164         .recalc_rate    = lan966x_gck_recalc_rate,
 165         .determine_rate = lan966x_gck_determine_rate,
 166         .set_parent     = lan966x_gck_set_parent,
 167         .get_parent     = lan966x_gck_get_parent,
 168 };
 169
 170 static struct clk_hw *lan966x_gck_clk_register(struct device *dev, int i)
 171 {
 172         struct lan966x_gck *priv;
 173         int ret;
 174
 175         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 176         if (!priv)
 177                 return ERR_PTR(-ENOMEM);
 178
 179         priv->reg = base + (i * 4);
 180         priv->hw.init = &init;
 181         ret = devm_clk_hw_register(dev, &priv->hw);
 182         if (ret)
 183                 return ERR_PTR(ret);
 184
 185         return &priv->hw;
 186 };
 187
 188 static int lan966x_gate_clk_register(struct device *dev,
 189                                      struct clk_hw_onecell_data *hw_data,
 190                                      void __iomem *gate_base)
 191 {
 192         int i;
 193
 194         for (i = GCK_GATE_UHPHS; i < N_CLOCKS; ++i) {
 195                 int idx = i - GCK_GATE_UHPHS;
 196
 197                 hw_data->hws[i] =
 198                         devm_clk_hw_register_gate(dev, clk_gate_desc[idx].name,
 199                                                   "lan966x", 0, gate_base,
 200                                                   clk_gate_desc[idx].bit_idx,
 201                                                   0, &clk_gate_lock);
 202
 203                 if (IS_ERR(hw_data->hws[i]))
 204                         return dev_err_probe(dev, PTR_ERR(hw_data->hws[i]),
 205                                              "failed to register %s clock\n",
 206                                              clk_gate_desc[idx].name);
 207         }
 208
 209         return 0;
 210 }
 211
 212 static int lan966x_clk_probe(struct platform_device *pdev)
 213 {
 214         struct clk_hw_onecell_data *hw_data;
 215         struct device *dev = &pdev->dev;
 216         void __iomem *gate_base;
 217         struct resource *res;
 218         int i, ret;
 219
 220         hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, N_CLOCKS),
 221                                GFP_KERNEL);
 222         if (!hw_data)
 223                 return -ENOMEM;
 224
 225         base = devm_platform_ioremap_resource(pdev, 0);
 226         if (IS_ERR(base))
 227                 return PTR_ERR(base);
 228
 229         init.ops = &lan966x_gck_ops;
 230
 231         hw_data->num = GCK_GATE_UHPHS;
 232
 233         for (i = 0; i < GCK_GATE_UHPHS; i++) {
 234                 init.name = clk_names[i];
 235                 hw_data->hws[i] = lan966x_gck_clk_register(dev, i);
 236                 if (IS_ERR(hw_data->hws[i])) {
 237                         dev_err(dev, "failed to register %s clock\n",
 238                                 init.name);
 239                         return PTR_ERR(hw_data->hws[i]);
 240                 }
 241         }
 242
 243         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 244         if (res) {
 245                 gate_base = devm_ioremap_resource(&pdev->dev, res);
 246                 if (IS_ERR(gate_base))
 247                         return PTR_ERR(gate_base);
 248
 249                 hw_data->num = N_CLOCKS;
 250
 251                 ret = lan966x_gate_clk_register(dev, hw_data, gate_base);
 252                 if (ret)
 253                         return ret;
 254         }
 255
 256         return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data);
 257 }
 258
 259 static const struct of_device_id lan966x_clk_dt_ids[] = {
 260         { .compatible = "microchip,lan966x-gck", },
 261         { }
 262 };
 263 MODULE_DEVICE_TABLE(of, lan966x_clk_dt_ids);
 264
 265 static struct platform_driver lan966x_clk_driver = {
 266         .probe  = lan966x_clk_probe,
 267         .driver = {
 268                 .name = "lan966x-clk",
 269                 .of_match_table = lan966x_clk_dt_ids,
 270         },
 271 };
 272 module_platform_driver(lan966x_clk_driver);
 273
 274 MODULE_AUTHOR("Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>");
 275 MODULE_DESCRIPTION("LAN966X clock driver");
 276 MODULE_LICENSE("GPL v2");