drivers/clk/clk-en7523.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <linux/delay.h>
   4 #include <linux/clk-provider.h>
   5 #include <linux/of.h>
   6 #include <linux/of_address.h>
   7 #include <linux/of_device.h>
   8 #include <linux/platform_device.h>
   9 #include <dt-bindings/clock/en7523-clk.h>
  10
  11 #define REG_PCI_CONTROL                 0x88
  12 #define   REG_PCI_CONTROL_PERSTOUT      BIT(29)
  13 #define   REG_PCI_CONTROL_PERSTOUT1     BIT(26)
  14 #define   REG_PCI_CONTROL_REFCLK_EN1    BIT(22)
  15 #define REG_GSW_CLK_DIV_SEL             0x1b4
  16 #define REG_EMI_CLK_DIV_SEL             0x1b8
  17 #define REG_BUS_CLK_DIV_SEL             0x1bc
  18 #define REG_SPI_CLK_DIV_SEL             0x1c4
  19 #define REG_SPI_CLK_FREQ_SEL            0x1c8
  20 #define REG_NPU_CLK_DIV_SEL             0x1fc
  21 #define REG_CRYPTO_CLKSRC               0x200
  22 #define REG_RESET_CONTROL               0x834
  23 #define   REG_RESET_CONTROL_PCIEHB      BIT(29)
  24 #define   REG_RESET_CONTROL_PCIE1       BIT(27)
  25 #define   REG_RESET_CONTROL_PCIE2       BIT(26)
  26
  27 struct en_clk_desc {
  28         int id;
  29         const char *name;
  30         u32 base_reg;
  31         u8 base_bits;
  32         u8 base_shift;
  33         union {
  34                 const unsigned int *base_values;
  35                 unsigned int base_value;
  36         };
  37         size_t n_base_values;
  38
  39         u16 div_reg;
  40         u8 div_bits;
  41         u8 div_shift;
  42         u16 div_val0;
  43         u8 div_step;
  44 };
  45
  46 struct en_clk_gate {
  47         void __iomem *base;
  48         struct clk_hw hw;
  49 };
  50
  51 static const u32 gsw_base[] = { 400000000, 500000000 };
  52 static const u32 emi_base[] = { 333000000, 400000000 };
  53 static const u32 bus_base[] = { 500000000, 540000000 };
  54 static const u32 slic_base[] = { 100000000, 3125000 };
  55 static const u32 npu_base[] = { 333000000, 400000000, 500000000 };
  56
  57 static const struct en_clk_desc en7523_base_clks[] = {
  58         {
  59                 .id = EN7523_CLK_GSW,
  60                 .name = "gsw",
  61
  62                 .base_reg = REG_GSW_CLK_DIV_SEL,
  63                 .base_bits = 1,
  64                 .base_shift = 8,
  65                 .base_values = gsw_base,
  66                 .n_base_values = ARRAY_SIZE(gsw_base),
  67
  68                 .div_bits = 3,
  69                 .div_shift = 0,
  70                 .div_step = 1,
  71         }, {
  72                 .id = EN7523_CLK_EMI,
  73                 .name = "emi",
  74
  75                 .base_reg = REG_EMI_CLK_DIV_SEL,
  76                 .base_bits = 1,
  77                 .base_shift = 8,
  78                 .base_values = emi_base,
  79                 .n_base_values = ARRAY_SIZE(emi_base),
  80
  81                 .div_bits = 3,
  82                 .div_shift = 0,
  83                 .div_step = 1,
  84         }, {
  85                 .id = EN7523_CLK_BUS,
  86                 .name = "bus",
  87
  88                 .base_reg = REG_BUS_CLK_DIV_SEL,
  89                 .base_bits = 1,
  90                 .base_shift = 8,
  91                 .base_values = bus_base,
  92                 .n_base_values = ARRAY_SIZE(bus_base),
  93
  94                 .div_bits = 3,
  95                 .div_shift = 0,
  96                 .div_step = 1,
  97         }, {
  98                 .id = EN7523_CLK_SLIC,
  99                 .name = "slic",
 100
 101                 .base_reg = REG_SPI_CLK_FREQ_SEL,
 102                 .base_bits = 1,
 103                 .base_shift = 0,
 104                 .base_values = slic_base,
 105                 .n_base_values = ARRAY_SIZE(slic_base),
 106
 107                 .div_reg = REG_SPI_CLK_DIV_SEL,
 108                 .div_bits = 5,
 109                 .div_shift = 24,
 110                 .div_val0 = 20,
 111                 .div_step = 2,
 112         }, {
 113                 .id = EN7523_CLK_SPI,
 114                 .name = "spi",
 115
 116                 .base_reg = REG_SPI_CLK_DIV_SEL,
 117
 118                 .base_value = 400000000,
 119
 120                 .div_bits = 5,
 121                 .div_shift = 8,
 122                 .div_val0 = 40,
 123                 .div_step = 2,
 124         }, {
 125                 .id = EN7523_CLK_NPU,
 126                 .name = "npu",
 127
 128                 .base_reg = REG_NPU_CLK_DIV_SEL,
 129                 .base_bits = 2,
 130                 .base_shift = 8,
 131                 .base_values = npu_base,
 132                 .n_base_values = ARRAY_SIZE(npu_base),
 133
 134                 .div_bits = 3,
 135                 .div_shift = 0,
 136                 .div_step = 1,
 137         }, {
 138                 .id = EN7523_CLK_CRYPTO,
 139                 .name = "crypto",
 140
 141                 .base_reg = REG_CRYPTO_CLKSRC,
 142                 .base_bits = 1,
 143                 .base_shift = 8,
 144                 .base_values = emi_base,
 145                 .n_base_values = ARRAY_SIZE(emi_base),
 146         }
 147 };
 148
 149 static const struct of_device_id of_match_clk_en7523[] = {
 150         { .compatible = "airoha,en7523-scu", },
 151         { /* sentinel */ }
 152 };
 153
 154 static unsigned int en7523_get_base_rate(void __iomem *base, unsigned int i)
 155 {
 156         const struct en_clk_desc *desc = &en7523_base_clks[i];
 157         u32 val;
 158
 159         if (!desc->base_bits)
 160                 return desc->base_value;
 161
 162         val = readl(base + desc->base_reg);
 163         val >>= desc->base_shift;
 164         val &= (1 << desc->base_bits) - 1;
 165
 166         if (val >= desc->n_base_values)
 167                 return 0;
 168
 169         return desc->base_values[val];
 170 }
 171
 172 static u32 en7523_get_div(void __iomem *base, int i)
 173 {
 174         const struct en_clk_desc *desc = &en7523_base_clks[i];
 175         u32 reg, val;
 176
 177         if (!desc->div_bits)
 178                 return 1;
 179
 180         reg = desc->div_reg ? desc->div_reg : desc->base_reg;
 181         val = readl(base + reg);
 182         val >>= desc->div_shift;
 183         val &= (1 << desc->div_bits) - 1;
 184
 185         if (!val && desc->div_val0)
 186                 return desc->div_val0;
 187
 188         return (val + 1) * desc->div_step;
 189 }
 190
 191 static int en7523_pci_is_enabled(struct clk_hw *hw)
 192 {
 193         struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
 194
 195         return !!(readl(cg->base + REG_PCI_CONTROL) & REG_PCI_CONTROL_REFCLK_EN1);
 196 }
 197
 198 static int en7523_pci_prepare(struct clk_hw *hw)
 199 {
 200         struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
 201         void __iomem *np_base = cg->base;
 202         u32 val, mask;
 203
 204         /* Need to pull device low before reset */
 205         val = readl(np_base + REG_PCI_CONTROL);
 206         val &= ~(REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT);
 207         writel(val, np_base + REG_PCI_CONTROL);
 208         usleep_range(1000, 2000);
 209
 210         /* Enable PCIe port 1 */
 211         val |= REG_PCI_CONTROL_REFCLK_EN1;
 212         writel(val, np_base + REG_PCI_CONTROL);
 213         usleep_range(1000, 2000);
 214
 215         /* Reset to default */
 216         val = readl(np_base + REG_RESET_CONTROL);
 217         mask = REG_RESET_CONTROL_PCIE1 | REG_RESET_CONTROL_PCIE2 |
 218                REG_RESET_CONTROL_PCIEHB;
 219         writel(val & ~mask, np_base + REG_RESET_CONTROL);
 220         usleep_range(1000, 2000);
 221         writel(val | mask, np_base + REG_RESET_CONTROL);
 222         msleep(100);
 223         writel(val & ~mask, np_base + REG_RESET_CONTROL);
 224         usleep_range(5000, 10000);
 225
 226         /* Release device */
 227         mask = REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT;
 228         val = readl(np_base + REG_PCI_CONTROL);
 229         writel(val & ~mask, np_base + REG_PCI_CONTROL);
 230         usleep_range(1000, 2000);
 231         writel(val | mask, np_base + REG_PCI_CONTROL);
 232         msleep(250);
 233
 234         return 0;
 235 }
 236
 237 static void en7523_pci_unprepare(struct clk_hw *hw)
 238 {
 239         struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
 240         void __iomem *np_base = cg->base;
 241         u32 val;
 242
 243         val = readl(np_base + REG_PCI_CONTROL);
 244         val &= ~REG_PCI_CONTROL_REFCLK_EN1;
 245         writel(val, np_base + REG_PCI_CONTROL);
 246 }
 247
 248 static struct clk_hw *en7523_register_pcie_clk(struct device *dev,
 249                                                void __iomem *np_base)
 250 {
 251         static const struct clk_ops pcie_gate_ops = {
 252                 .is_enabled = en7523_pci_is_enabled,
 253                 .prepare = en7523_pci_prepare,
 254                 .unprepare = en7523_pci_unprepare,
 255         };
 256         struct clk_init_data init = {
 257                 .name = "pcie",
 258                 .ops = &pcie_gate_ops,
 259         };
 260         struct en_clk_gate *cg;
 261
 262         cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
 263         if (!cg)
 264                 return NULL;
 265
 266         cg->base = np_base;
 267         cg->hw.init = &init;
 268         en7523_pci_unprepare(&cg->hw);
 269
 270         if (clk_hw_register(dev, &cg->hw))
 271                 return NULL;
 272
 273         return &cg->hw;
 274 }
 275
 276 static void en7523_register_clocks(struct device *dev, struct clk_hw_onecell_data *clk_data,
 277                                    void __iomem *base, void __iomem *np_base)
 278 {
 279         struct clk_hw *hw;
 280         u32 rate;
 281         int i;
 282
 283         for (i = 0; i < ARRAY_SIZE(en7523_base_clks); i++) {
 284                 const struct en_clk_desc *desc = &en7523_base_clks[i];
 285
 286                 rate = en7523_get_base_rate(base, i);
 287                 rate /= en7523_get_div(base, i);
 288
 289                 hw = clk_hw_register_fixed_rate(dev, desc->name, NULL, 0, rate);
 290                 if (IS_ERR(hw)) {
 291                         pr_err("Failed to register clk %s: %ld\n",
 292                                desc->name, PTR_ERR(hw));
 293                         continue;
 294                 }
 295
 296                 clk_data->hws[desc->id] = hw;
 297         }
 298
 299         hw = en7523_register_pcie_clk(dev, np_base);
 300         clk_data->hws[EN7523_CLK_PCIE] = hw;
 301
 302         clk_data->num = EN7523_NUM_CLOCKS;
 303 }
 304
 305 static int en7523_clk_probe(struct platform_device *pdev)
 306 {
 307         struct device_node *node = pdev->dev.of_node;
 308         struct clk_hw_onecell_data *clk_data;
 309         void __iomem *base, *np_base;
 310         int r;
 311
 312         base = devm_platform_ioremap_resource(pdev, 0);
 313         if (IS_ERR(base))
 314                 return PTR_ERR(base);
 315
 316         np_base = devm_platform_ioremap_resource(pdev, 1);
 317         if (IS_ERR(base))
 318                 return PTR_ERR(np_base);
 319
 320         clk_data = devm_kzalloc(&pdev->dev,
 321                                 struct_size(clk_data, hws, EN7523_NUM_CLOCKS),
 322                                 GFP_KERNEL);
 323         if (!clk_data)
 324                 return -ENOMEM;
 325
 326         en7523_register_clocks(&pdev->dev, clk_data, base, np_base);
 327
 328         r = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
 329         if (r)
 330                 dev_err(&pdev->dev,
 331                         "could not register clock provider: %s: %d\n",
 332                         pdev->name, r);
 333
 334         return r;
 335 }
 336
 337 static struct platform_driver clk_en7523_drv = {
 338         .probe = en7523_clk_probe,
 339         .driver = {
 340                 .name = "clk-en7523",
 341                 .of_match_table = of_match_clk_en7523,
 342                 .suppress_bind_attrs = true,
 343         },
 344 };
 345
 346 static int __init clk_en7523_init(void)
 347 {
 348         return platform_driver_register(&clk_en7523_drv);
 349 }
 350
 351 arch_initcall(clk_en7523_init);