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_master_get_devdata(spi->master); 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_master_get_devdata(spi->master); 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 static int dw_spi_canaan_k210_init(struct platform_device *pdev, 240 struct dw_spi_mmio *dwsmmio) 241 { 242 /* 243 * The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is 244 * documented to have a 32 word deep TX and RX FIFO, which 245 * spi_hw_init() detects. However, when the RX FIFO is filled up to 246 * 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this 247 * problem by force setting fifo_len to 31. 248 */ 249 dwsmmio->dws.fifo_len = 31; 250 251 return 0; 252 } 253 254 static void dw_spi_elba_override_cs(struct regmap *syscon, int cs, int enable) 255 { 256 regmap_update_bits(syscon, ELBA_SPICS_REG, ELBA_SPICS_MASK(cs), 257 ELBA_SPICS_SET(cs, enable)); 258 } 259 260 static void dw_spi_elba_set_cs(struct spi_device *spi, bool enable) 261 { 262 struct dw_spi *dws = spi_master_get_devdata(spi->master); 263 struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws); 264 struct regmap *syscon = dwsmmio->priv; 265 u8 cs; 266 267 cs = spi->chip_select; 268 if (cs < 2) 269 dw_spi_elba_override_cs(syscon, spi->chip_select, enable); 270 271 /* 272 * The DW SPI controller needs a native CS bit selected to start 273 * the serial engine. 274 */ 275 spi->chip_select = 0; 276 dw_spi_set_cs(spi, enable); 277 spi->chip_select = cs; 278 } 279 280 static int dw_spi_elba_init(struct platform_device *pdev, 281 struct dw_spi_mmio *dwsmmio) 282 { 283 struct regmap *syscon; 284 285 syscon = syscon_regmap_lookup_by_phandle(dev_of_node(&pdev->dev), 286 "amd,pensando-elba-syscon"); 287 if (IS_ERR(syscon)) 288 return dev_err_probe(&pdev->dev, PTR_ERR(syscon), 289 "syscon regmap lookup failed\n"); 290 291 dwsmmio->priv = syscon; 292 dwsmmio->dws.set_cs = dw_spi_elba_set_cs; 293 294 return 0; 295 } 296 297 static int dw_spi_mmio_probe(struct platform_device *pdev) 298 { 299 int (*init_func)(struct platform_device *pdev, 300 struct dw_spi_mmio *dwsmmio); 301 struct dw_spi_mmio *dwsmmio; 302 struct resource *mem; 303 struct dw_spi *dws; 304 int ret; 305 int num_cs; 306 307 dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), 308 GFP_KERNEL); 309 if (!dwsmmio) 310 return -ENOMEM; 311 312 dws = &dwsmmio->dws; 313 314 /* Get basic io resource and map it */ 315 dws->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem); 316 if (IS_ERR(dws->regs)) 317 return PTR_ERR(dws->regs); 318 319 dws->paddr = mem->start; 320 321 dws->irq = platform_get_irq(pdev, 0); 322 if (dws->irq < 0) 323 return dws->irq; /* -ENXIO */ 324 325 dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); 326 if (IS_ERR(dwsmmio->clk)) 327 return PTR_ERR(dwsmmio->clk); 328 ret = clk_prepare_enable(dwsmmio->clk); 329 if (ret) 330 return ret; 331 332 /* Optional clock needed to access the registers */ 333 dwsmmio->pclk = devm_clk_get_optional(&pdev->dev, "pclk"); 334 if (IS_ERR(dwsmmio->pclk)) { 335 ret = PTR_ERR(dwsmmio->pclk); 336 goto out_clk; 337 } 338 ret = clk_prepare_enable(dwsmmio->pclk); 339 if (ret) 340 goto out_clk; 341 342 /* find an optional reset controller */ 343 dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi"); 344 if (IS_ERR(dwsmmio->rstc)) { 345 ret = PTR_ERR(dwsmmio->rstc); 346 goto out_clk; 347 } 348 reset_control_deassert(dwsmmio->rstc); 349 350 dws->bus_num = pdev->id; 351 352 dws->max_freq = clk_get_rate(dwsmmio->clk); 353 354 device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width); 355 356 num_cs = 4; 357 358 device_property_read_u32(&pdev->dev, "num-cs", &num_cs); 359 360 dws->num_cs = num_cs; 361 362 init_func = device_get_match_data(&pdev->dev); 363 if (init_func) { 364 ret = init_func(pdev, dwsmmio); 365 if (ret) 366 goto out; 367 } 368 369 pm_runtime_enable(&pdev->dev); 370 371 ret = dw_spi_add_host(&pdev->dev, dws); 372 if (ret) 373 goto out; 374 375 platform_set_drvdata(pdev, dwsmmio); 376 return 0; 377 378 out: 379 pm_runtime_disable(&pdev->dev); 380 clk_disable_unprepare(dwsmmio->pclk); 381 out_clk: 382 clk_disable_unprepare(dwsmmio->clk); 383 reset_control_assert(dwsmmio->rstc); 384 385 return ret; 386 } 387 388 static void dw_spi_mmio_remove(struct platform_device *pdev) 389 { 390 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 391 392 dw_spi_remove_host(&dwsmmio->dws); 393 pm_runtime_disable(&pdev->dev); 394 clk_disable_unprepare(dwsmmio->pclk); 395 clk_disable_unprepare(dwsmmio->clk); 396 reset_control_assert(dwsmmio->rstc); 397 } 398 399 static const struct of_device_id dw_spi_mmio_of_match[] = { 400 { .compatible = "snps,dw-apb-ssi", .data = dw_spi_pssi_init}, 401 { .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init}, 402 { .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init}, 403 { .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init}, 404 { .compatible = "renesas,rzn1-spi", .data = dw_spi_pssi_init}, 405 { .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_hssi_init}, 406 { .compatible = "intel,keembay-ssi", .data = dw_spi_intel_init}, 407 { .compatible = "intel,thunderbay-ssi", .data = dw_spi_intel_init}, 408 { .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init}, 409 { .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init}, 410 { .compatible = "amd,pensando-elba-spi", .data = dw_spi_elba_init}, 411 { /* end of table */} 412 }; 413 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); 414 415 #ifdef CONFIG_ACPI 416 static const struct acpi_device_id dw_spi_mmio_acpi_match[] = { 417 {"HISI0173", (kernel_ulong_t)dw_spi_pssi_init}, 418 {}, 419 }; 420 MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match); 421 #endif 422 423 static struct platform_driver dw_spi_mmio_driver = { 424 .probe = dw_spi_mmio_probe, 425 .remove_new = dw_spi_mmio_remove, 426 .driver = { 427 .name = DRIVER_NAME, 428 .of_match_table = dw_spi_mmio_of_match, 429 .acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match), 430 }, 431 }; 432 module_platform_driver(dw_spi_mmio_driver); 433 434 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 435 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 436 MODULE_LICENSE("GPL v2"); 437 MODULE_IMPORT_NS(SPI_DW_CORE); 438