1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Memory-mapped interface driver for DW SPI Core 4 * 5 * Copyright (c) 2010, Octasic semiconductor. 6 */ 7 8 #include <linux/clk.h> 9 #include <linux/err.h> 10 #include <linux/platform_device.h> 11 #include <linux/pm_runtime.h> 12 #include <linux/slab.h> 13 #include <linux/spi/spi.h> 14 #include <linux/scatterlist.h> 15 #include <linux/mfd/syscon.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/of_platform.h> 19 #include <linux/acpi.h> 20 #include <linux/property.h> 21 #include <linux/regmap.h> 22 #include <linux/reset.h> 23 24 #include "spi-dw.h" 25 26 #define DRIVER_NAME "dw_spi_mmio" 27 28 struct dw_spi_mmio { 29 struct dw_spi dws; 30 struct clk *clk; 31 struct clk *pclk; 32 void *priv; 33 struct reset_control *rstc; 34 }; 35 36 #define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24 37 #define OCELOT_IF_SI_OWNER_OFFSET 4 38 #define JAGUAR2_IF_SI_OWNER_OFFSET 6 39 #define MSCC_IF_SI_OWNER_MASK GENMASK(1, 0) 40 #define MSCC_IF_SI_OWNER_SISL 0 41 #define MSCC_IF_SI_OWNER_SIBM 1 42 #define MSCC_IF_SI_OWNER_SIMC 2 43 44 #define MSCC_SPI_MST_SW_MODE 0x14 45 #define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE BIT(13) 46 #define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x) (x << 5) 47 48 #define SPARX5_FORCE_ENA 0xa4 49 #define SPARX5_FORCE_VAL 0xa8 50 51 struct dw_spi_mscc { 52 struct regmap *syscon; 53 void __iomem *spi_mst; /* Not sparx5 */ 54 }; 55 56 /* 57 * Elba SoC does not use ssi, pin override is used for cs 0,1 and 58 * gpios for cs 2,3 as defined in the device tree. 59 * 60 * cs: | 1 0 61 * bit: |---3-------2-------1-------0 62 * | cs1 cs1_ovr cs0 cs0_ovr 63 */ 64 #define ELBA_SPICS_REG 0x2468 65 #define ELBA_SPICS_OFFSET(cs) ((cs) << 1) 66 #define ELBA_SPICS_MASK(cs) (GENMASK(1, 0) << ELBA_SPICS_OFFSET(cs)) 67 #define ELBA_SPICS_SET(cs, val) \ 68 ((((val) << 1) | BIT(0)) << ELBA_SPICS_OFFSET(cs)) 69 70 /* 71 * The Designware SPI controller (referred to as master in the documentation) 72 * automatically deasserts chip select when the tx fifo is empty. The chip 73 * selects then needs to be either driven as GPIOs or, for the first 4 using 74 * the SPI boot controller registers. the final chip select is an OR gate 75 * between the Designware SPI controller and the SPI boot controller. 76 */ 77 static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable) 78 { 79 struct dw_spi *dws = spi_controller_get_devdata(spi->controller); 80 struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws); 81 struct dw_spi_mscc *dwsmscc = dwsmmio->priv; 82 u32 cs = spi_get_chipselect(spi, 0); 83 84 if (cs < 4) { 85 u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE; 86 87 if (!enable) 88 sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs)); 89 90 writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE); 91 } 92 93 dw_spi_set_cs(spi, enable); 94 } 95 96 static int dw_spi_mscc_init(struct platform_device *pdev, 97 struct dw_spi_mmio *dwsmmio, 98 const char *cpu_syscon, u32 if_si_owner_offset) 99 { 100 struct dw_spi_mscc *dwsmscc; 101 102 dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL); 103 if (!dwsmscc) 104 return -ENOMEM; 105 106 dwsmscc->spi_mst = devm_platform_ioremap_resource(pdev, 1); 107 if (IS_ERR(dwsmscc->spi_mst)) { 108 dev_err(&pdev->dev, "SPI_MST region map failed\n"); 109 return PTR_ERR(dwsmscc->spi_mst); 110 } 111 112 dwsmscc->syscon = syscon_regmap_lookup_by_compatible(cpu_syscon); 113 if (IS_ERR(dwsmscc->syscon)) 114 return PTR_ERR(dwsmscc->syscon); 115 116 /* Deassert all CS */ 117 writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE); 118 119 /* Select the owner of the SI interface */ 120 regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL, 121 MSCC_IF_SI_OWNER_MASK << if_si_owner_offset, 122 MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset); 123 124 dwsmmio->dws.set_cs = dw_spi_mscc_set_cs; 125 dwsmmio->priv = dwsmscc; 126 127 return 0; 128 } 129 130 static int dw_spi_mscc_ocelot_init(struct platform_device *pdev, 131 struct dw_spi_mmio *dwsmmio) 132 { 133 return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon", 134 OCELOT_IF_SI_OWNER_OFFSET); 135 } 136 137 static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev, 138 struct dw_spi_mmio *dwsmmio) 139 { 140 return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon", 141 JAGUAR2_IF_SI_OWNER_OFFSET); 142 } 143 144 /* 145 * The Designware SPI controller (referred to as master in the 146 * documentation) automatically deasserts chip select when the tx fifo 147 * is empty. The chip selects then needs to be driven by a CS override 148 * register. enable is an active low signal. 149 */ 150 static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable) 151 { 152 struct dw_spi *dws = spi_controller_get_devdata(spi->controller); 153 struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws); 154 struct dw_spi_mscc *dwsmscc = dwsmmio->priv; 155 u8 cs = spi_get_chipselect(spi, 0); 156 157 if (!enable) { 158 /* CS override drive enable */ 159 regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1); 160 /* Now set CSx enabled */ 161 regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs)); 162 /* Allow settle */ 163 usleep_range(1, 5); 164 } else { 165 /* CS value */ 166 regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0); 167 /* Allow settle */ 168 usleep_range(1, 5); 169 /* CS override drive disable */ 170 regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0); 171 } 172 173 dw_spi_set_cs(spi, enable); 174 } 175 176 static int dw_spi_mscc_sparx5_init(struct platform_device *pdev, 177 struct dw_spi_mmio *dwsmmio) 178 { 179 const char *syscon_name = "microchip,sparx5-cpu-syscon"; 180 struct device *dev = &pdev->dev; 181 struct dw_spi_mscc *dwsmscc; 182 183 if (!IS_ENABLED(CONFIG_SPI_MUX)) { 184 dev_err(dev, "This driver needs CONFIG_SPI_MUX\n"); 185 return -EOPNOTSUPP; 186 } 187 188 dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL); 189 if (!dwsmscc) 190 return -ENOMEM; 191 192 dwsmscc->syscon = 193 syscon_regmap_lookup_by_compatible(syscon_name); 194 if (IS_ERR(dwsmscc->syscon)) { 195 dev_err(dev, "No syscon map %s\n", syscon_name); 196 return PTR_ERR(dwsmscc->syscon); 197 } 198 199 dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs; 200 dwsmmio->priv = dwsmscc; 201 202 return 0; 203 } 204 205 static int dw_spi_alpine_init(struct platform_device *pdev, 206 struct dw_spi_mmio *dwsmmio) 207 { 208 dwsmmio->dws.caps = DW_SPI_CAP_CS_OVERRIDE; 209 210 return 0; 211 } 212 213 static int dw_spi_pssi_init(struct platform_device *pdev, 214 struct dw_spi_mmio *dwsmmio) 215 { 216 dw_spi_dma_setup_generic(&dwsmmio->dws); 217 218 return 0; 219 } 220 221 static int dw_spi_hssi_init(struct platform_device *pdev, 222 struct dw_spi_mmio *dwsmmio) 223 { 224 dwsmmio->dws.ip = DW_HSSI_ID; 225 226 dw_spi_dma_setup_generic(&dwsmmio->dws); 227 228 return 0; 229 } 230 231 static int dw_spi_intel_init(struct platform_device *pdev, 232 struct dw_spi_mmio *dwsmmio) 233 { 234 dwsmmio->dws.ip = DW_HSSI_ID; 235 236 return 0; 237 } 238 239 /* 240 * DMA-based mem ops are not configured for this device and are not tested. 241 */ 242 static int dw_spi_mountevans_imc_init(struct platform_device *pdev, 243 struct dw_spi_mmio *dwsmmio) 244 { 245 /* 246 * The Intel Mount Evans SoC's Integrated Management Complex DW 247 * apb_ssi_v4.02a controller has an errata where a full TX FIFO can 248 * result in data corruption. The suggested workaround is to never 249 * completely fill the FIFO. The TX FIFO has a size of 32 so the 250 * fifo_len is set to 31. 251 */ 252 dwsmmio->dws.fifo_len = 31; 253 254 return 0; 255 } 256 257 static int dw_spi_canaan_k210_init(struct platform_device *pdev, 258 struct dw_spi_mmio *dwsmmio) 259 { 260 /* 261 * The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is 262 * documented to have a 32 word deep TX and RX FIFO, which 263 * spi_hw_init() detects. However, when the RX FIFO is filled up to 264 * 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this 265 * problem by force setting fifo_len to 31. 266 */ 267 dwsmmio->dws.fifo_len = 31; 268 269 return 0; 270 } 271 272 static void dw_spi_elba_override_cs(struct regmap *syscon, int cs, int enable) 273 { 274 regmap_update_bits(syscon, ELBA_SPICS_REG, ELBA_SPICS_MASK(cs), 275 ELBA_SPICS_SET(cs, enable)); 276 } 277 278 static void dw_spi_elba_set_cs(struct spi_device *spi, bool enable) 279 { 280 struct dw_spi *dws = spi_controller_get_devdata(spi->controller); 281 struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws); 282 struct regmap *syscon = dwsmmio->priv; 283 u8 cs; 284 285 cs = spi_get_chipselect(spi, 0); 286 if (cs < 2) 287 dw_spi_elba_override_cs(syscon, spi_get_chipselect(spi, 0), enable); 288 289 /* 290 * The DW SPI controller needs a native CS bit selected to start 291 * the serial engine. 292 */ 293 spi_set_chipselect(spi, 0, 0); 294 dw_spi_set_cs(spi, enable); 295 spi_set_chipselect(spi, 0, cs); 296 } 297 298 static int dw_spi_elba_init(struct platform_device *pdev, 299 struct dw_spi_mmio *dwsmmio) 300 { 301 struct regmap *syscon; 302 303 syscon = syscon_regmap_lookup_by_phandle(dev_of_node(&pdev->dev), 304 "amd,pensando-elba-syscon"); 305 if (IS_ERR(syscon)) 306 return dev_err_probe(&pdev->dev, PTR_ERR(syscon), 307 "syscon regmap lookup failed\n"); 308 309 dwsmmio->priv = syscon; 310 dwsmmio->dws.set_cs = dw_spi_elba_set_cs; 311 312 return 0; 313 } 314 315 static int dw_spi_mmio_probe(struct platform_device *pdev) 316 { 317 int (*init_func)(struct platform_device *pdev, 318 struct dw_spi_mmio *dwsmmio); 319 struct dw_spi_mmio *dwsmmio; 320 struct resource *mem; 321 struct dw_spi *dws; 322 int ret; 323 int num_cs; 324 325 dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), 326 GFP_KERNEL); 327 if (!dwsmmio) 328 return -ENOMEM; 329 330 dws = &dwsmmio->dws; 331 332 /* Get basic io resource and map it */ 333 dws->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem); 334 if (IS_ERR(dws->regs)) 335 return PTR_ERR(dws->regs); 336 337 dws->paddr = mem->start; 338 339 dws->irq = platform_get_irq(pdev, 0); 340 if (dws->irq < 0) 341 return dws->irq; /* -ENXIO */ 342 343 dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); 344 if (IS_ERR(dwsmmio->clk)) 345 return PTR_ERR(dwsmmio->clk); 346 ret = clk_prepare_enable(dwsmmio->clk); 347 if (ret) 348 return ret; 349 350 /* Optional clock needed to access the registers */ 351 dwsmmio->pclk = devm_clk_get_optional(&pdev->dev, "pclk"); 352 if (IS_ERR(dwsmmio->pclk)) { 353 ret = PTR_ERR(dwsmmio->pclk); 354 goto out_clk; 355 } 356 ret = clk_prepare_enable(dwsmmio->pclk); 357 if (ret) 358 goto out_clk; 359 360 /* find an optional reset controller */ 361 dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi"); 362 if (IS_ERR(dwsmmio->rstc)) { 363 ret = PTR_ERR(dwsmmio->rstc); 364 goto out_clk; 365 } 366 reset_control_deassert(dwsmmio->rstc); 367 368 dws->bus_num = pdev->id; 369 370 dws->max_freq = clk_get_rate(dwsmmio->clk); 371 372 if (device_property_read_u32(&pdev->dev, "reg-io-width", 373 &dws->reg_io_width)) 374 dws->reg_io_width = 4; 375 376 num_cs = 4; 377 378 device_property_read_u32(&pdev->dev, "num-cs", &num_cs); 379 380 dws->num_cs = num_cs; 381 382 init_func = device_get_match_data(&pdev->dev); 383 if (init_func) { 384 ret = init_func(pdev, dwsmmio); 385 if (ret) 386 goto out; 387 } 388 389 pm_runtime_enable(&pdev->dev); 390 391 ret = dw_spi_add_host(&pdev->dev, dws); 392 if (ret) 393 goto out; 394 395 platform_set_drvdata(pdev, dwsmmio); 396 return 0; 397 398 out: 399 pm_runtime_disable(&pdev->dev); 400 clk_disable_unprepare(dwsmmio->pclk); 401 out_clk: 402 clk_disable_unprepare(dwsmmio->clk); 403 reset_control_assert(dwsmmio->rstc); 404 405 return ret; 406 } 407 408 static void dw_spi_mmio_remove(struct platform_device *pdev) 409 { 410 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 411 412 dw_spi_remove_host(&dwsmmio->dws); 413 pm_runtime_disable(&pdev->dev); 414 clk_disable_unprepare(dwsmmio->pclk); 415 clk_disable_unprepare(dwsmmio->clk); 416 reset_control_assert(dwsmmio->rstc); 417 } 418 419 static const struct of_device_id dw_spi_mmio_of_match[] = { 420 { .compatible = "snps,dw-apb-ssi", .data = dw_spi_pssi_init}, 421 { .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init}, 422 { .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init}, 423 { .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init}, 424 { .compatible = "renesas,rzn1-spi", .data = dw_spi_pssi_init}, 425 { .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_hssi_init}, 426 { .compatible = "intel,keembay-ssi", .data = dw_spi_intel_init}, 427 { .compatible = "intel,thunderbay-ssi", .data = dw_spi_intel_init}, 428 { 429 .compatible = "intel,mountevans-imc-ssi", 430 .data = dw_spi_mountevans_imc_init, 431 }, 432 { .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init}, 433 { .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init}, 434 { .compatible = "amd,pensando-elba-spi", .data = dw_spi_elba_init}, 435 { /* end of table */} 436 }; 437 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); 438 439 #ifdef CONFIG_ACPI 440 static const struct acpi_device_id dw_spi_mmio_acpi_match[] = { 441 {"HISI0173", (kernel_ulong_t)dw_spi_pssi_init}, 442 {}, 443 }; 444 MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match); 445 #endif 446 447 static struct platform_driver dw_spi_mmio_driver = { 448 .probe = dw_spi_mmio_probe, 449 .remove_new = dw_spi_mmio_remove, 450 .driver = { 451 .name = DRIVER_NAME, 452 .of_match_table = dw_spi_mmio_of_match, 453 .acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match), 454 }, 455 }; 456 module_platform_driver(dw_spi_mmio_driver); 457 458 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 459 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 460 MODULE_LICENSE("GPL v2"); 461 MODULE_IMPORT_NS(SPI_DW_CORE); 462