drivers/clk/mvebu/ap-cpu-clk.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Marvell Armada AP CPU Clock Controller
   4  *
   5  * Copyright (C) 2018 Marvell
   6  *
   7  * Omri Itach <omrii@marvell.com>
   8  * Gregory Clement <gregory.clement@bootlin.com>
   9  */
  10
  11 #define pr_fmt(fmt) "ap-cpu-clk: " fmt
  12
  13 #include <linux/clk-provider.h>
  14 #include <linux/clk.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/regmap.h>
  21 #include "armada_ap_cp_helper.h"
  22
  23 #define AP806_CPU_CLUSTER0              0
  24 #define AP806_CPU_CLUSTER1              1
  25 #define AP806_CPUS_PER_CLUSTER          2
  26 #define APN806_CPU1_MASK                0x1
  27
  28 #define APN806_CLUSTER_NUM_OFFSET       8
  29 #define APN806_CLUSTER_NUM_MASK         BIT(APN806_CLUSTER_NUM_OFFSET)
  30
  31 #define APN806_MAX_DIVIDER              32
  32
  33 /*
  34  * struct cpu_dfs_regs: CPU DFS register mapping
  35  * @divider_reg: full integer ratio from PLL frequency to CPU clock frequency
  36  * @force_reg: request to force new ratio regardless of relation to other clocks
  37  * @ratio_reg: central request to switch ratios
  38  */
  39 struct cpu_dfs_regs {
  40         unsigned int divider_reg;
  41         unsigned int force_reg;
  42         unsigned int ratio_reg;
  43         unsigned int ratio_state_reg;
  44         unsigned int divider_mask;
  45         unsigned int cluster_offset;
  46         unsigned int force_mask;
  47         int divider_offset;
  48         int divider_ratio;
  49         int ratio_offset;
  50         int ratio_state_offset;
  51         int ratio_state_cluster_offset;
  52 };
  53
  54 /* AP806 CPU DFS register mapping*/
  55 #define AP806_CA72MP2_0_PLL_CR_0_REG_OFFSET             0x278
  56 #define AP806_CA72MP2_0_PLL_CR_1_REG_OFFSET             0x280
  57 #define AP806_CA72MP2_0_PLL_CR_2_REG_OFFSET             0x284
  58 #define AP806_CA72MP2_0_PLL_SR_REG_OFFSET               0xC94
  59
  60 #define AP806_CA72MP2_0_PLL_CR_CLUSTER_OFFSET           0x14
  61 #define AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET         0
  62 #define AP806_PLL_CR_CPU_CLK_DIV_RATIO                  0
  63 #define AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK \
  64                         (0x3f << AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET)
  65 #define AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET      24
  66 #define AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK \
  67                         (0x1 << AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET)
  68 #define AP806_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET      16
  69 #define AP806_CA72MP2_0_PLL_RATIO_STABLE_OFFSET 0
  70 #define AP806_CA72MP2_0_PLL_RATIO_STATE                 11
  71
  72 #define STATUS_POLL_PERIOD_US           1
  73 #define STATUS_POLL_TIMEOUT_US          1000000
  74
  75 #define to_ap_cpu_clk(_hw) container_of(_hw, struct ap_cpu_clk, hw)
  76
  77 static const struct cpu_dfs_regs ap806_dfs_regs = {
  78         .divider_reg = AP806_CA72MP2_0_PLL_CR_0_REG_OFFSET,
  79         .force_reg = AP806_CA72MP2_0_PLL_CR_1_REG_OFFSET,
  80         .ratio_reg = AP806_CA72MP2_0_PLL_CR_2_REG_OFFSET,
  81         .ratio_state_reg = AP806_CA72MP2_0_PLL_SR_REG_OFFSET,
  82         .divider_mask = AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK,
  83         .cluster_offset = AP806_CA72MP2_0_PLL_CR_CLUSTER_OFFSET,
  84         .force_mask = AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK,
  85         .divider_offset = AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET,
  86         .divider_ratio = AP806_PLL_CR_CPU_CLK_DIV_RATIO,
  87         .ratio_offset = AP806_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET,
  88         .ratio_state_offset = AP806_CA72MP2_0_PLL_RATIO_STABLE_OFFSET,
  89         .ratio_state_cluster_offset = AP806_CA72MP2_0_PLL_RATIO_STABLE_OFFSET,
  90 };
  91
  92 /* AP807 CPU DFS register mapping */
  93 #define AP807_DEVICE_GENERAL_CONTROL_10_REG_OFFSET              0x278
  94 #define AP807_DEVICE_GENERAL_CONTROL_11_REG_OFFSET              0x27c
  95 #define AP807_DEVICE_GENERAL_STATUS_6_REG_OFFSET                0xc98
  96 #define AP807_CA72MP2_0_PLL_CR_CLUSTER_OFFSET                   0x8
  97 #define AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET                 18
  98 #define AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK \
  99                 (0x3f << AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET)
 100 #define AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_OFFSET                 12
 101 #define AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_MASK \
 102                 (0x3f << AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_OFFSET)
 103 #define AP807_PLL_CR_CPU_CLK_DIV_RATIO                          3
 104 #define AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET              0
 105 #define AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK \
 106                 (0x3 << AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET)
 107 #define AP807_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET              6
 108 #define AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_OFFSET          20
 109 #define AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_CLUSTER_OFFSET  3
 110
 111 static const struct cpu_dfs_regs ap807_dfs_regs = {
 112         .divider_reg = AP807_DEVICE_GENERAL_CONTROL_10_REG_OFFSET,
 113         .force_reg = AP807_DEVICE_GENERAL_CONTROL_11_REG_OFFSET,
 114         .ratio_reg = AP807_DEVICE_GENERAL_CONTROL_11_REG_OFFSET,
 115         .ratio_state_reg = AP807_DEVICE_GENERAL_STATUS_6_REG_OFFSET,
 116         .divider_mask = AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK,
 117         .cluster_offset = AP807_CA72MP2_0_PLL_CR_CLUSTER_OFFSET,
 118         .force_mask = AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK,
 119         .divider_offset = AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET,
 120         .divider_ratio = AP807_PLL_CR_CPU_CLK_DIV_RATIO,
 121         .ratio_offset = AP807_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET,
 122         .ratio_state_offset = AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_OFFSET,
 123         .ratio_state_cluster_offset =
 124                 AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_CLUSTER_OFFSET
 125 };
 126
 127 /*
 128  * struct ap806_clk: CPU cluster clock controller instance
 129  * @cluster: Cluster clock controller index
 130  * @clk_name: Cluster clock controller name
 131  * @dev : Cluster clock device
 132  * @hw: HW specific structure of Cluster clock controller
 133  * @pll_cr_base: CA72MP2 Register base (Device Sample at Reset register)
 134  */
 135 struct ap_cpu_clk {
 136         unsigned int cluster;
 137         const char *clk_name;
 138         struct device *dev;
 139         struct clk_hw hw;
 140         struct regmap *pll_cr_base;
 141         const struct cpu_dfs_regs *pll_regs;
 142 };
 143
 144 static unsigned long ap_cpu_clk_recalc_rate(struct clk_hw *hw,
 145                                             unsigned long parent_rate)
 146 {
 147         struct ap_cpu_clk *clk = to_ap_cpu_clk(hw);
 148         unsigned int cpu_clkdiv_reg;
 149         int cpu_clkdiv_ratio;
 150
 151         cpu_clkdiv_reg = clk->pll_regs->divider_reg +
 152                 (clk->cluster * clk->pll_regs->cluster_offset);
 153         regmap_read(clk->pll_cr_base, cpu_clkdiv_reg, &cpu_clkdiv_ratio);
 154         cpu_clkdiv_ratio &= clk->pll_regs->divider_mask;
 155         cpu_clkdiv_ratio >>= clk->pll_regs->divider_offset;
 156
 157         return parent_rate / cpu_clkdiv_ratio;
 158 }
 159
 160 static int ap_cpu_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 161                                unsigned long parent_rate)
 162 {
 163         struct ap_cpu_clk *clk = to_ap_cpu_clk(hw);
 164         int ret, reg, divider = parent_rate / rate;
 165         unsigned int cpu_clkdiv_reg, cpu_force_reg, cpu_ratio_reg, stable_bit;
 166
 167         cpu_clkdiv_reg = clk->pll_regs->divider_reg +
 168                 (clk->cluster * clk->pll_regs->cluster_offset);
 169         cpu_force_reg = clk->pll_regs->force_reg +
 170                 (clk->cluster * clk->pll_regs->cluster_offset);
 171         cpu_ratio_reg = clk->pll_regs->ratio_reg +
 172                 (clk->cluster * clk->pll_regs->cluster_offset);
 173
 174         regmap_read(clk->pll_cr_base, cpu_clkdiv_reg, &reg);
 175         reg &= ~(clk->pll_regs->divider_mask);
 176         reg |= (divider << clk->pll_regs->divider_offset);
 177
 178         /*
 179          * AP807 CPU divider has two channels with ratio 1:3 and divider_ratio
 180          * is 1. Otherwise, in the case of the AP806, divider_ratio is 0.
 181          */
 182         if (clk->pll_regs->divider_ratio) {
 183                 reg &= ~(AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_MASK);
 184                 reg |= ((divider * clk->pll_regs->divider_ratio) <<
 185                                 AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_OFFSET);
 186         }
 187         regmap_write(clk->pll_cr_base, cpu_clkdiv_reg, reg);
 188
 189
 190         regmap_update_bits(clk->pll_cr_base, cpu_force_reg,
 191                            clk->pll_regs->force_mask,
 192                            clk->pll_regs->force_mask);
 193
 194         regmap_update_bits(clk->pll_cr_base, cpu_ratio_reg,
 195                            BIT(clk->pll_regs->ratio_offset),
 196                            BIT(clk->pll_regs->ratio_offset));
 197
 198         stable_bit = BIT(clk->pll_regs->ratio_state_offset +
 199                          clk->cluster *
 200                          clk->pll_regs->ratio_state_cluster_offset);
 201         ret = regmap_read_poll_timeout(clk->pll_cr_base,
 202                                        clk->pll_regs->ratio_state_reg, reg,
 203                                        reg & stable_bit, STATUS_POLL_PERIOD_US,
 204                                        STATUS_POLL_TIMEOUT_US);
 205         if (ret)
 206                 return ret;
 207
 208         regmap_update_bits(clk->pll_cr_base, cpu_ratio_reg,
 209                            BIT(clk->pll_regs->ratio_offset), 0);
 210
 211         return 0;
 212 }
 213
 214 static long ap_cpu_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 215                                   unsigned long *parent_rate)
 216 {
 217         int divider = *parent_rate / rate;
 218
 219         divider = min(divider, APN806_MAX_DIVIDER);
 220
 221         return *parent_rate / divider;
 222 }
 223
 224 static const struct clk_ops ap_cpu_clk_ops = {
 225         .recalc_rate    = ap_cpu_clk_recalc_rate,
 226         .round_rate     = ap_cpu_clk_round_rate,
 227         .set_rate       = ap_cpu_clk_set_rate,
 228 };
 229
 230 static int ap_cpu_clock_probe(struct platform_device *pdev)
 231 {
 232         int ret, nclusters = 0, cluster_index = 0;
 233         struct device *dev = &pdev->dev;
 234         struct device_node *dn, *np = dev->of_node;
 235         struct clk_hw_onecell_data *ap_cpu_data;
 236         struct ap_cpu_clk *ap_cpu_clk;
 237         struct regmap *regmap;
 238
 239         regmap = syscon_node_to_regmap(np->parent);
 240         if (IS_ERR(regmap)) {
 241                 pr_err("cannot get pll_cr_base regmap\n");
 242                 return PTR_ERR(regmap);
 243         }
 244
 245         /*
 246          * AP806 has 4 cpus and DFS for AP806 is controlled per
 247          * cluster (2 CPUs per cluster), cpu0 and cpu1 are fixed to
 248          * cluster0 while cpu2 and cpu3 are fixed to cluster1 whether
 249          * they are enabled or not.  Since cpu0 is the boot cpu, then
 250          * cluster0 must exist.  If cpu2 or cpu3 is enabled, cluster1
 251          * will exist and the cluster number is 2; otherwise the
 252          * cluster number is 1.
 253          */
 254         nclusters = 1;
 255         for_each_of_cpu_node(dn) {
 256                 int cpu, err;
 257
 258                 err = of_property_read_u32(dn, "reg", &cpu);
 259                 if (WARN_ON(err))
 260                         return err;
 261
 262                 /* If cpu2 or cpu3 is enabled */
 263                 if (cpu & APN806_CLUSTER_NUM_MASK) {
 264                         nclusters = 2;
 265                         break;
 266                 }
 267         }
 268         /*
 269          * DFS for AP806 is controlled per cluster (2 CPUs per cluster),
 270          * so allocate structs per cluster
 271          */
 272         ap_cpu_clk = devm_kcalloc(dev, nclusters, sizeof(*ap_cpu_clk),
 273                                   GFP_KERNEL);
 274         if (!ap_cpu_clk)
 275                 return -ENOMEM;
 276
 277         ap_cpu_data = devm_kzalloc(dev, struct_size(ap_cpu_data, hws,
 278                                                     nclusters),
 279                                 GFP_KERNEL);
 280         if (!ap_cpu_data)
 281                 return -ENOMEM;
 282
 283         for_each_of_cpu_node(dn) {
 284                 char *clk_name = "cpu-cluster-0";
 285                 struct clk_init_data init;
 286                 const char *parent_name;
 287                 struct clk *parent;
 288                 int cpu, err;
 289
 290                 err = of_property_read_u32(dn, "reg", &cpu);
 291                 if (WARN_ON(err))
 292                         return err;
 293
 294                 cluster_index = cpu & APN806_CLUSTER_NUM_MASK;
 295                 cluster_index >>= APN806_CLUSTER_NUM_OFFSET;
 296
 297                 /* Initialize once for one cluster */
 298                 if (ap_cpu_data->hws[cluster_index])
 299                         continue;
 300
 301                 parent = of_clk_get(np, cluster_index);
 302                 if (IS_ERR(parent)) {
 303                         dev_err(dev, "Could not get the clock parent\n");
 304                         return -EINVAL;
 305                 }
 306                 parent_name =  __clk_get_name(parent);
 307                 clk_name[12] += cluster_index;
 308                 ap_cpu_clk[cluster_index].clk_name =
 309                         ap_cp_unique_name(dev, np->parent, clk_name);
 310                 ap_cpu_clk[cluster_index].cluster = cluster_index;
 311                 ap_cpu_clk[cluster_index].pll_cr_base = regmap;
 312                 ap_cpu_clk[cluster_index].hw.init = &init;
 313                 ap_cpu_clk[cluster_index].dev = dev;
 314                 ap_cpu_clk[cluster_index].pll_regs = of_device_get_match_data(&pdev->dev);
 315
 316                 init.name = ap_cpu_clk[cluster_index].clk_name;
 317                 init.ops = &ap_cpu_clk_ops;
 318                 init.num_parents = 1;
 319                 init.parent_names = &parent_name;
 320
 321                 ret = devm_clk_hw_register(dev, &ap_cpu_clk[cluster_index].hw);
 322                 if (ret)
 323                         return ret;
 324                 ap_cpu_data->hws[cluster_index] = &ap_cpu_clk[cluster_index].hw;
 325         }
 326
 327         ap_cpu_data->num = cluster_index + 1;
 328
 329         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, ap_cpu_data);
 330         if (ret)
 331                 dev_err(dev, "failed to register OF clock provider\n");
 332
 333         return ret;
 334 }
 335
 336 static const struct of_device_id ap_cpu_clock_of_match[] = {
 337         {
 338                 .compatible = "marvell,ap806-cpu-clock",
 339                 .data = &ap806_dfs_regs,
 340         },
 341         {
 342                 .compatible = "marvell,ap807-cpu-clock",
 343                 .data = &ap807_dfs_regs,
 344         },
 345         { }
 346 };
 347
 348 static struct platform_driver ap_cpu_clock_driver = {
 349         .probe = ap_cpu_clock_probe,
 350         .driver         = {
 351                 .name   = "marvell-ap-cpu-clock",
 352                 .of_match_table = ap_cpu_clock_of_match,
 353                 .suppress_bind_attrs = true,
 354         },
 355 };
 356 builtin_platform_driver(ap_cpu_clock_driver);