| 1 | /* |
| 2 | * Copyright (C) 2009 Texas Instruments. |
| 3 | * Copyright (C) 2010 EF Johnson Technologies |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/io.h> |
| 18 | #include <linux/gpio.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/delay.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <linux/err.h> |
| 23 | #include <linux/clk.h> |
| 24 | #include <linux/dmaengine.h> |
| 25 | #include <linux/dma-mapping.h> |
| 26 | #include <linux/edma.h> |
| 27 | #include <linux/of.h> |
| 28 | #include <linux/of_device.h> |
| 29 | #include <linux/of_gpio.h> |
| 30 | #include <linux/spi/spi.h> |
| 31 | #include <linux/spi/spi_bitbang.h> |
| 32 | #include <linux/slab.h> |
| 33 | |
| 34 | #include <linux/platform_data/spi-davinci.h> |
| 35 | |
| 36 | #define SPI_NO_RESOURCE ((resource_size_t)-1) |
| 37 | |
| 38 | #define CS_DEFAULT 0xFF |
| 39 | |
| 40 | #define SPIFMT_PHASE_MASK BIT(16) |
| 41 | #define SPIFMT_POLARITY_MASK BIT(17) |
| 42 | #define SPIFMT_DISTIMER_MASK BIT(18) |
| 43 | #define SPIFMT_SHIFTDIR_MASK BIT(20) |
| 44 | #define SPIFMT_WAITENA_MASK BIT(21) |
| 45 | #define SPIFMT_PARITYENA_MASK BIT(22) |
| 46 | #define SPIFMT_ODD_PARITY_MASK BIT(23) |
| 47 | #define SPIFMT_WDELAY_MASK 0x3f000000u |
| 48 | #define SPIFMT_WDELAY_SHIFT 24 |
| 49 | #define SPIFMT_PRESCALE_SHIFT 8 |
| 50 | |
| 51 | /* SPIPC0 */ |
| 52 | #define SPIPC0_DIFUN_MASK BIT(11) /* MISO */ |
| 53 | #define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */ |
| 54 | #define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */ |
| 55 | #define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */ |
| 56 | |
| 57 | #define SPIINT_MASKALL 0x0101035F |
| 58 | #define SPIINT_MASKINT 0x0000015F |
| 59 | #define SPI_INTLVL_1 0x000001FF |
| 60 | #define SPI_INTLVL_0 0x00000000 |
| 61 | |
| 62 | /* SPIDAT1 (upper 16 bit defines) */ |
| 63 | #define SPIDAT1_CSHOLD_MASK BIT(12) |
| 64 | #define SPIDAT1_WDEL BIT(10) |
| 65 | |
| 66 | /* SPIGCR1 */ |
| 67 | #define SPIGCR1_CLKMOD_MASK BIT(1) |
| 68 | #define SPIGCR1_MASTER_MASK BIT(0) |
| 69 | #define SPIGCR1_POWERDOWN_MASK BIT(8) |
| 70 | #define SPIGCR1_LOOPBACK_MASK BIT(16) |
| 71 | #define SPIGCR1_SPIENA_MASK BIT(24) |
| 72 | |
| 73 | /* SPIBUF */ |
| 74 | #define SPIBUF_TXFULL_MASK BIT(29) |
| 75 | #define SPIBUF_RXEMPTY_MASK BIT(31) |
| 76 | |
| 77 | /* SPIDELAY */ |
| 78 | #define SPIDELAY_C2TDELAY_SHIFT 24 |
| 79 | #define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT) |
| 80 | #define SPIDELAY_T2CDELAY_SHIFT 16 |
| 81 | #define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT) |
| 82 | #define SPIDELAY_T2EDELAY_SHIFT 8 |
| 83 | #define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT) |
| 84 | #define SPIDELAY_C2EDELAY_SHIFT 0 |
| 85 | #define SPIDELAY_C2EDELAY_MASK 0xFF |
| 86 | |
| 87 | /* Error Masks */ |
| 88 | #define SPIFLG_DLEN_ERR_MASK BIT(0) |
| 89 | #define SPIFLG_TIMEOUT_MASK BIT(1) |
| 90 | #define SPIFLG_PARERR_MASK BIT(2) |
| 91 | #define SPIFLG_DESYNC_MASK BIT(3) |
| 92 | #define SPIFLG_BITERR_MASK BIT(4) |
| 93 | #define SPIFLG_OVRRUN_MASK BIT(6) |
| 94 | #define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24) |
| 95 | #define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \ |
| 96 | | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \ |
| 97 | | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \ |
| 98 | | SPIFLG_OVRRUN_MASK) |
| 99 | |
| 100 | #define SPIINT_DMA_REQ_EN BIT(16) |
| 101 | |
| 102 | /* SPI Controller registers */ |
| 103 | #define SPIGCR0 0x00 |
| 104 | #define SPIGCR1 0x04 |
| 105 | #define SPIINT 0x08 |
| 106 | #define SPILVL 0x0c |
| 107 | #define SPIFLG 0x10 |
| 108 | #define SPIPC0 0x14 |
| 109 | #define SPIDAT1 0x3c |
| 110 | #define SPIBUF 0x40 |
| 111 | #define SPIDELAY 0x48 |
| 112 | #define SPIDEF 0x4c |
| 113 | #define SPIFMT0 0x50 |
| 114 | |
| 115 | /* SPI Controller driver's private data. */ |
| 116 | struct davinci_spi { |
| 117 | struct spi_bitbang bitbang; |
| 118 | struct clk *clk; |
| 119 | |
| 120 | u8 version; |
| 121 | resource_size_t pbase; |
| 122 | void __iomem *base; |
| 123 | u32 irq; |
| 124 | struct completion done; |
| 125 | |
| 126 | const void *tx; |
| 127 | void *rx; |
| 128 | int rcount; |
| 129 | int wcount; |
| 130 | |
| 131 | struct dma_chan *dma_rx; |
| 132 | struct dma_chan *dma_tx; |
| 133 | int dma_rx_chnum; |
| 134 | int dma_tx_chnum; |
| 135 | |
| 136 | struct davinci_spi_platform_data pdata; |
| 137 | |
| 138 | void (*get_rx)(u32 rx_data, struct davinci_spi *); |
| 139 | u32 (*get_tx)(struct davinci_spi *); |
| 140 | |
| 141 | u8 *bytes_per_word; |
| 142 | |
| 143 | u8 prescaler_limit; |
| 144 | }; |
| 145 | |
| 146 | static struct davinci_spi_config davinci_spi_default_cfg; |
| 147 | |
| 148 | static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi) |
| 149 | { |
| 150 | if (dspi->rx) { |
| 151 | u8 *rx = dspi->rx; |
| 152 | *rx++ = (u8)data; |
| 153 | dspi->rx = rx; |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi) |
| 158 | { |
| 159 | if (dspi->rx) { |
| 160 | u16 *rx = dspi->rx; |
| 161 | *rx++ = (u16)data; |
| 162 | dspi->rx = rx; |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi) |
| 167 | { |
| 168 | u32 data = 0; |
| 169 | |
| 170 | if (dspi->tx) { |
| 171 | const u8 *tx = dspi->tx; |
| 172 | |
| 173 | data = *tx++; |
| 174 | dspi->tx = tx; |
| 175 | } |
| 176 | return data; |
| 177 | } |
| 178 | |
| 179 | static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi) |
| 180 | { |
| 181 | u32 data = 0; |
| 182 | |
| 183 | if (dspi->tx) { |
| 184 | const u16 *tx = dspi->tx; |
| 185 | |
| 186 | data = *tx++; |
| 187 | dspi->tx = tx; |
| 188 | } |
| 189 | return data; |
| 190 | } |
| 191 | |
| 192 | static inline void set_io_bits(void __iomem *addr, u32 bits) |
| 193 | { |
| 194 | u32 v = ioread32(addr); |
| 195 | |
| 196 | v |= bits; |
| 197 | iowrite32(v, addr); |
| 198 | } |
| 199 | |
| 200 | static inline void clear_io_bits(void __iomem *addr, u32 bits) |
| 201 | { |
| 202 | u32 v = ioread32(addr); |
| 203 | |
| 204 | v &= ~bits; |
| 205 | iowrite32(v, addr); |
| 206 | } |
| 207 | |
| 208 | /* |
| 209 | * Interface to control the chip select signal |
| 210 | */ |
| 211 | static void davinci_spi_chipselect(struct spi_device *spi, int value) |
| 212 | { |
| 213 | struct davinci_spi *dspi; |
| 214 | struct davinci_spi_platform_data *pdata; |
| 215 | struct davinci_spi_config *spicfg = spi->controller_data; |
| 216 | u8 chip_sel = spi->chip_select; |
| 217 | u16 spidat1 = CS_DEFAULT; |
| 218 | bool gpio_chipsel = false; |
| 219 | int gpio; |
| 220 | |
| 221 | dspi = spi_master_get_devdata(spi->master); |
| 222 | pdata = &dspi->pdata; |
| 223 | |
| 224 | if (spi->cs_gpio >= 0) { |
| 225 | /* SPI core parse and update master->cs_gpio */ |
| 226 | gpio_chipsel = true; |
| 227 | gpio = spi->cs_gpio; |
| 228 | } |
| 229 | |
| 230 | /* program delay transfers if tx_delay is non zero */ |
| 231 | if (spicfg->wdelay) |
| 232 | spidat1 |= SPIDAT1_WDEL; |
| 233 | |
| 234 | /* |
| 235 | * Board specific chip select logic decides the polarity and cs |
| 236 | * line for the controller |
| 237 | */ |
| 238 | if (gpio_chipsel) { |
| 239 | if (value == BITBANG_CS_ACTIVE) |
| 240 | gpio_set_value(gpio, spi->mode & SPI_CS_HIGH); |
| 241 | else |
| 242 | gpio_set_value(gpio, !(spi->mode & SPI_CS_HIGH)); |
| 243 | } else { |
| 244 | if (value == BITBANG_CS_ACTIVE) { |
| 245 | spidat1 |= SPIDAT1_CSHOLD_MASK; |
| 246 | spidat1 &= ~(0x1 << chip_sel); |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | iowrite16(spidat1, dspi->base + SPIDAT1 + 2); |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * davinci_spi_get_prescale - Calculates the correct prescale value |
| 255 | * @maxspeed_hz: the maximum rate the SPI clock can run at |
| 256 | * |
| 257 | * This function calculates the prescale value that generates a clock rate |
| 258 | * less than or equal to the specified maximum. |
| 259 | * |
| 260 | * Returns: calculated prescale value for easy programming into SPI registers |
| 261 | * or negative error number if valid prescalar cannot be updated. |
| 262 | */ |
| 263 | static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, |
| 264 | u32 max_speed_hz) |
| 265 | { |
| 266 | int ret; |
| 267 | |
| 268 | /* Subtract 1 to match what will be programmed into SPI register. */ |
| 269 | ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1; |
| 270 | |
| 271 | if (ret < dspi->prescaler_limit || ret > 255) |
| 272 | return -EINVAL; |
| 273 | |
| 274 | return ret; |
| 275 | } |
| 276 | |
| 277 | /** |
| 278 | * davinci_spi_setup_transfer - This functions will determine transfer method |
| 279 | * @spi: spi device on which data transfer to be done |
| 280 | * @t: spi transfer in which transfer info is filled |
| 281 | * |
| 282 | * This function determines data transfer method (8/16/32 bit transfer). |
| 283 | * It will also set the SPI Clock Control register according to |
| 284 | * SPI slave device freq. |
| 285 | */ |
| 286 | static int davinci_spi_setup_transfer(struct spi_device *spi, |
| 287 | struct spi_transfer *t) |
| 288 | { |
| 289 | |
| 290 | struct davinci_spi *dspi; |
| 291 | struct davinci_spi_config *spicfg; |
| 292 | u8 bits_per_word = 0; |
| 293 | u32 hz = 0, spifmt = 0; |
| 294 | int prescale; |
| 295 | |
| 296 | dspi = spi_master_get_devdata(spi->master); |
| 297 | spicfg = spi->controller_data; |
| 298 | if (!spicfg) |
| 299 | spicfg = &davinci_spi_default_cfg; |
| 300 | |
| 301 | if (t) { |
| 302 | bits_per_word = t->bits_per_word; |
| 303 | hz = t->speed_hz; |
| 304 | } |
| 305 | |
| 306 | /* if bits_per_word is not set then set it default */ |
| 307 | if (!bits_per_word) |
| 308 | bits_per_word = spi->bits_per_word; |
| 309 | |
| 310 | /* |
| 311 | * Assign function pointer to appropriate transfer method |
| 312 | * 8bit, 16bit or 32bit transfer |
| 313 | */ |
| 314 | if (bits_per_word <= 8) { |
| 315 | dspi->get_rx = davinci_spi_rx_buf_u8; |
| 316 | dspi->get_tx = davinci_spi_tx_buf_u8; |
| 317 | dspi->bytes_per_word[spi->chip_select] = 1; |
| 318 | } else { |
| 319 | dspi->get_rx = davinci_spi_rx_buf_u16; |
| 320 | dspi->get_tx = davinci_spi_tx_buf_u16; |
| 321 | dspi->bytes_per_word[spi->chip_select] = 2; |
| 322 | } |
| 323 | |
| 324 | if (!hz) |
| 325 | hz = spi->max_speed_hz; |
| 326 | |
| 327 | /* Set up SPIFMTn register, unique to this chipselect. */ |
| 328 | |
| 329 | prescale = davinci_spi_get_prescale(dspi, hz); |
| 330 | if (prescale < 0) |
| 331 | return prescale; |
| 332 | |
| 333 | spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f); |
| 334 | |
| 335 | if (spi->mode & SPI_LSB_FIRST) |
| 336 | spifmt |= SPIFMT_SHIFTDIR_MASK; |
| 337 | |
| 338 | if (spi->mode & SPI_CPOL) |
| 339 | spifmt |= SPIFMT_POLARITY_MASK; |
| 340 | |
| 341 | if (!(spi->mode & SPI_CPHA)) |
| 342 | spifmt |= SPIFMT_PHASE_MASK; |
| 343 | |
| 344 | /* |
| 345 | * Assume wdelay is used only on SPI peripherals that has this field |
| 346 | * in SPIFMTn register and when it's configured from board file or DT. |
| 347 | */ |
| 348 | if (spicfg->wdelay) |
| 349 | spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT) |
| 350 | & SPIFMT_WDELAY_MASK); |
| 351 | |
| 352 | /* |
| 353 | * Version 1 hardware supports two basic SPI modes: |
| 354 | * - Standard SPI mode uses 4 pins, with chipselect |
| 355 | * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS) |
| 356 | * (distinct from SPI_3WIRE, with just one data wire; |
| 357 | * or similar variants without MOSI or without MISO) |
| 358 | * |
| 359 | * Version 2 hardware supports an optional handshaking signal, |
| 360 | * so it can support two more modes: |
| 361 | * - 5 pin SPI variant is standard SPI plus SPI_READY |
| 362 | * - 4 pin with enable is (SPI_READY | SPI_NO_CS) |
| 363 | */ |
| 364 | |
| 365 | if (dspi->version == SPI_VERSION_2) { |
| 366 | |
| 367 | u32 delay = 0; |
| 368 | |
| 369 | if (spicfg->odd_parity) |
| 370 | spifmt |= SPIFMT_ODD_PARITY_MASK; |
| 371 | |
| 372 | if (spicfg->parity_enable) |
| 373 | spifmt |= SPIFMT_PARITYENA_MASK; |
| 374 | |
| 375 | if (spicfg->timer_disable) { |
| 376 | spifmt |= SPIFMT_DISTIMER_MASK; |
| 377 | } else { |
| 378 | delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT) |
| 379 | & SPIDELAY_C2TDELAY_MASK; |
| 380 | delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT) |
| 381 | & SPIDELAY_T2CDELAY_MASK; |
| 382 | } |
| 383 | |
| 384 | if (spi->mode & SPI_READY) { |
| 385 | spifmt |= SPIFMT_WAITENA_MASK; |
| 386 | delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT) |
| 387 | & SPIDELAY_T2EDELAY_MASK; |
| 388 | delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT) |
| 389 | & SPIDELAY_C2EDELAY_MASK; |
| 390 | } |
| 391 | |
| 392 | iowrite32(delay, dspi->base + SPIDELAY); |
| 393 | } |
| 394 | |
| 395 | iowrite32(spifmt, dspi->base + SPIFMT0); |
| 396 | |
| 397 | return 0; |
| 398 | } |
| 399 | |
| 400 | static int davinci_spi_of_setup(struct spi_device *spi) |
| 401 | { |
| 402 | struct davinci_spi_config *spicfg = spi->controller_data; |
| 403 | struct device_node *np = spi->dev.of_node; |
| 404 | u32 prop; |
| 405 | |
| 406 | if (spicfg == NULL && np) { |
| 407 | spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL); |
| 408 | if (!spicfg) |
| 409 | return -ENOMEM; |
| 410 | *spicfg = davinci_spi_default_cfg; |
| 411 | /* override with dt configured values */ |
| 412 | if (!of_property_read_u32(np, "ti,spi-wdelay", &prop)) |
| 413 | spicfg->wdelay = (u8)prop; |
| 414 | spi->controller_data = spicfg; |
| 415 | } |
| 416 | |
| 417 | return 0; |
| 418 | } |
| 419 | |
| 420 | /** |
| 421 | * davinci_spi_setup - This functions will set default transfer method |
| 422 | * @spi: spi device on which data transfer to be done |
| 423 | * |
| 424 | * This functions sets the default transfer method. |
| 425 | */ |
| 426 | static int davinci_spi_setup(struct spi_device *spi) |
| 427 | { |
| 428 | int retval = 0; |
| 429 | struct davinci_spi *dspi; |
| 430 | struct davinci_spi_platform_data *pdata; |
| 431 | struct spi_master *master = spi->master; |
| 432 | struct device_node *np = spi->dev.of_node; |
| 433 | bool internal_cs = true; |
| 434 | |
| 435 | dspi = spi_master_get_devdata(spi->master); |
| 436 | pdata = &dspi->pdata; |
| 437 | |
| 438 | if (!(spi->mode & SPI_NO_CS)) { |
| 439 | if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) { |
| 440 | retval = gpio_direction_output( |
| 441 | spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); |
| 442 | internal_cs = false; |
| 443 | } else if (pdata->chip_sel && |
| 444 | spi->chip_select < pdata->num_chipselect && |
| 445 | pdata->chip_sel[spi->chip_select] != SPI_INTERN_CS) { |
| 446 | spi->cs_gpio = pdata->chip_sel[spi->chip_select]; |
| 447 | retval = gpio_direction_output( |
| 448 | spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); |
| 449 | internal_cs = false; |
| 450 | } |
| 451 | |
| 452 | if (retval) { |
| 453 | dev_err(&spi->dev, "GPIO %d setup failed (%d)\n", |
| 454 | spi->cs_gpio, retval); |
| 455 | return retval; |
| 456 | } |
| 457 | |
| 458 | if (internal_cs) |
| 459 | set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); |
| 460 | } |
| 461 | |
| 462 | if (spi->mode & SPI_READY) |
| 463 | set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK); |
| 464 | |
| 465 | if (spi->mode & SPI_LOOP) |
| 466 | set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); |
| 467 | else |
| 468 | clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); |
| 469 | |
| 470 | return davinci_spi_of_setup(spi); |
| 471 | } |
| 472 | |
| 473 | static void davinci_spi_cleanup(struct spi_device *spi) |
| 474 | { |
| 475 | struct davinci_spi_config *spicfg = spi->controller_data; |
| 476 | |
| 477 | spi->controller_data = NULL; |
| 478 | if (spi->dev.of_node) |
| 479 | kfree(spicfg); |
| 480 | } |
| 481 | |
| 482 | static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) |
| 483 | { |
| 484 | struct device *sdev = dspi->bitbang.master->dev.parent; |
| 485 | |
| 486 | if (int_status & SPIFLG_TIMEOUT_MASK) { |
| 487 | dev_dbg(sdev, "SPI Time-out Error\n"); |
| 488 | return -ETIMEDOUT; |
| 489 | } |
| 490 | if (int_status & SPIFLG_DESYNC_MASK) { |
| 491 | dev_dbg(sdev, "SPI Desynchronization Error\n"); |
| 492 | return -EIO; |
| 493 | } |
| 494 | if (int_status & SPIFLG_BITERR_MASK) { |
| 495 | dev_dbg(sdev, "SPI Bit error\n"); |
| 496 | return -EIO; |
| 497 | } |
| 498 | |
| 499 | if (dspi->version == SPI_VERSION_2) { |
| 500 | if (int_status & SPIFLG_DLEN_ERR_MASK) { |
| 501 | dev_dbg(sdev, "SPI Data Length Error\n"); |
| 502 | return -EIO; |
| 503 | } |
| 504 | if (int_status & SPIFLG_PARERR_MASK) { |
| 505 | dev_dbg(sdev, "SPI Parity Error\n"); |
| 506 | return -EIO; |
| 507 | } |
| 508 | if (int_status & SPIFLG_OVRRUN_MASK) { |
| 509 | dev_dbg(sdev, "SPI Data Overrun error\n"); |
| 510 | return -EIO; |
| 511 | } |
| 512 | if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) { |
| 513 | dev_dbg(sdev, "SPI Buffer Init Active\n"); |
| 514 | return -EBUSY; |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | return 0; |
| 519 | } |
| 520 | |
| 521 | /** |
| 522 | * davinci_spi_process_events - check for and handle any SPI controller events |
| 523 | * @dspi: the controller data |
| 524 | * |
| 525 | * This function will check the SPIFLG register and handle any events that are |
| 526 | * detected there |
| 527 | */ |
| 528 | static int davinci_spi_process_events(struct davinci_spi *dspi) |
| 529 | { |
| 530 | u32 buf, status, errors = 0, spidat1; |
| 531 | |
| 532 | buf = ioread32(dspi->base + SPIBUF); |
| 533 | |
| 534 | if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) { |
| 535 | dspi->get_rx(buf & 0xFFFF, dspi); |
| 536 | dspi->rcount--; |
| 537 | } |
| 538 | |
| 539 | status = ioread32(dspi->base + SPIFLG); |
| 540 | |
| 541 | if (unlikely(status & SPIFLG_ERROR_MASK)) { |
| 542 | errors = status & SPIFLG_ERROR_MASK; |
| 543 | goto out; |
| 544 | } |
| 545 | |
| 546 | if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) { |
| 547 | spidat1 = ioread32(dspi->base + SPIDAT1); |
| 548 | dspi->wcount--; |
| 549 | spidat1 &= ~0xFFFF; |
| 550 | spidat1 |= 0xFFFF & dspi->get_tx(dspi); |
| 551 | iowrite32(spidat1, dspi->base + SPIDAT1); |
| 552 | } |
| 553 | |
| 554 | out: |
| 555 | return errors; |
| 556 | } |
| 557 | |
| 558 | static void davinci_spi_dma_rx_callback(void *data) |
| 559 | { |
| 560 | struct davinci_spi *dspi = (struct davinci_spi *)data; |
| 561 | |
| 562 | dspi->rcount = 0; |
| 563 | |
| 564 | if (!dspi->wcount && !dspi->rcount) |
| 565 | complete(&dspi->done); |
| 566 | } |
| 567 | |
| 568 | static void davinci_spi_dma_tx_callback(void *data) |
| 569 | { |
| 570 | struct davinci_spi *dspi = (struct davinci_spi *)data; |
| 571 | |
| 572 | dspi->wcount = 0; |
| 573 | |
| 574 | if (!dspi->wcount && !dspi->rcount) |
| 575 | complete(&dspi->done); |
| 576 | } |
| 577 | |
| 578 | /** |
| 579 | * davinci_spi_bufs - functions which will handle transfer data |
| 580 | * @spi: spi device on which data transfer to be done |
| 581 | * @t: spi transfer in which transfer info is filled |
| 582 | * |
| 583 | * This function will put data to be transferred into data register |
| 584 | * of SPI controller and then wait until the completion will be marked |
| 585 | * by the IRQ Handler. |
| 586 | */ |
| 587 | static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) |
| 588 | { |
| 589 | struct davinci_spi *dspi; |
| 590 | int data_type, ret = -ENOMEM; |
| 591 | u32 tx_data, spidat1; |
| 592 | u32 errors = 0; |
| 593 | struct davinci_spi_config *spicfg; |
| 594 | struct davinci_spi_platform_data *pdata; |
| 595 | unsigned uninitialized_var(rx_buf_count); |
| 596 | void *dummy_buf = NULL; |
| 597 | struct scatterlist sg_rx, sg_tx; |
| 598 | |
| 599 | dspi = spi_master_get_devdata(spi->master); |
| 600 | pdata = &dspi->pdata; |
| 601 | spicfg = (struct davinci_spi_config *)spi->controller_data; |
| 602 | if (!spicfg) |
| 603 | spicfg = &davinci_spi_default_cfg; |
| 604 | |
| 605 | /* convert len to words based on bits_per_word */ |
| 606 | data_type = dspi->bytes_per_word[spi->chip_select]; |
| 607 | |
| 608 | dspi->tx = t->tx_buf; |
| 609 | dspi->rx = t->rx_buf; |
| 610 | dspi->wcount = t->len / data_type; |
| 611 | dspi->rcount = dspi->wcount; |
| 612 | |
| 613 | spidat1 = ioread32(dspi->base + SPIDAT1); |
| 614 | |
| 615 | clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); |
| 616 | set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); |
| 617 | |
| 618 | reinit_completion(&dspi->done); |
| 619 | |
| 620 | if (spicfg->io_type == SPI_IO_TYPE_INTR) |
| 621 | set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); |
| 622 | |
| 623 | if (spicfg->io_type != SPI_IO_TYPE_DMA) { |
| 624 | /* start the transfer */ |
| 625 | dspi->wcount--; |
| 626 | tx_data = dspi->get_tx(dspi); |
| 627 | spidat1 &= 0xFFFF0000; |
| 628 | spidat1 |= tx_data & 0xFFFF; |
| 629 | iowrite32(spidat1, dspi->base + SPIDAT1); |
| 630 | } else { |
| 631 | struct dma_slave_config dma_rx_conf = { |
| 632 | .direction = DMA_DEV_TO_MEM, |
| 633 | .src_addr = (unsigned long)dspi->pbase + SPIBUF, |
| 634 | .src_addr_width = data_type, |
| 635 | .src_maxburst = 1, |
| 636 | }; |
| 637 | struct dma_slave_config dma_tx_conf = { |
| 638 | .direction = DMA_MEM_TO_DEV, |
| 639 | .dst_addr = (unsigned long)dspi->pbase + SPIDAT1, |
| 640 | .dst_addr_width = data_type, |
| 641 | .dst_maxburst = 1, |
| 642 | }; |
| 643 | struct dma_async_tx_descriptor *rxdesc; |
| 644 | struct dma_async_tx_descriptor *txdesc; |
| 645 | void *buf; |
| 646 | |
| 647 | dummy_buf = kzalloc(t->len, GFP_KERNEL); |
| 648 | if (!dummy_buf) |
| 649 | goto err_alloc_dummy_buf; |
| 650 | |
| 651 | dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf); |
| 652 | dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf); |
| 653 | |
| 654 | sg_init_table(&sg_rx, 1); |
| 655 | if (!t->rx_buf) |
| 656 | buf = dummy_buf; |
| 657 | else |
| 658 | buf = t->rx_buf; |
| 659 | t->rx_dma = dma_map_single(&spi->dev, buf, |
| 660 | t->len, DMA_FROM_DEVICE); |
| 661 | if (!t->rx_dma) { |
| 662 | ret = -EFAULT; |
| 663 | goto err_rx_map; |
| 664 | } |
| 665 | sg_dma_address(&sg_rx) = t->rx_dma; |
| 666 | sg_dma_len(&sg_rx) = t->len; |
| 667 | |
| 668 | sg_init_table(&sg_tx, 1); |
| 669 | if (!t->tx_buf) |
| 670 | buf = dummy_buf; |
| 671 | else |
| 672 | buf = (void *)t->tx_buf; |
| 673 | t->tx_dma = dma_map_single(&spi->dev, buf, |
| 674 | t->len, DMA_TO_DEVICE); |
| 675 | if (!t->tx_dma) { |
| 676 | ret = -EFAULT; |
| 677 | goto err_tx_map; |
| 678 | } |
| 679 | sg_dma_address(&sg_tx) = t->tx_dma; |
| 680 | sg_dma_len(&sg_tx) = t->len; |
| 681 | |
| 682 | rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx, |
| 683 | &sg_rx, 1, DMA_DEV_TO_MEM, |
| 684 | DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
| 685 | if (!rxdesc) |
| 686 | goto err_desc; |
| 687 | |
| 688 | txdesc = dmaengine_prep_slave_sg(dspi->dma_tx, |
| 689 | &sg_tx, 1, DMA_MEM_TO_DEV, |
| 690 | DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
| 691 | if (!txdesc) |
| 692 | goto err_desc; |
| 693 | |
| 694 | rxdesc->callback = davinci_spi_dma_rx_callback; |
| 695 | rxdesc->callback_param = (void *)dspi; |
| 696 | txdesc->callback = davinci_spi_dma_tx_callback; |
| 697 | txdesc->callback_param = (void *)dspi; |
| 698 | |
| 699 | if (pdata->cshold_bug) |
| 700 | iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2); |
| 701 | |
| 702 | dmaengine_submit(rxdesc); |
| 703 | dmaengine_submit(txdesc); |
| 704 | |
| 705 | dma_async_issue_pending(dspi->dma_rx); |
| 706 | dma_async_issue_pending(dspi->dma_tx); |
| 707 | |
| 708 | set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); |
| 709 | } |
| 710 | |
| 711 | /* Wait for the transfer to complete */ |
| 712 | if (spicfg->io_type != SPI_IO_TYPE_POLL) { |
| 713 | wait_for_completion_interruptible(&(dspi->done)); |
| 714 | } else { |
| 715 | while (dspi->rcount > 0 || dspi->wcount > 0) { |
| 716 | errors = davinci_spi_process_events(dspi); |
| 717 | if (errors) |
| 718 | break; |
| 719 | cpu_relax(); |
| 720 | } |
| 721 | } |
| 722 | |
| 723 | clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL); |
| 724 | if (spicfg->io_type == SPI_IO_TYPE_DMA) { |
| 725 | clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); |
| 726 | |
| 727 | dma_unmap_single(&spi->dev, t->rx_dma, |
| 728 | t->len, DMA_FROM_DEVICE); |
| 729 | dma_unmap_single(&spi->dev, t->tx_dma, |
| 730 | t->len, DMA_TO_DEVICE); |
| 731 | kfree(dummy_buf); |
| 732 | } |
| 733 | |
| 734 | clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); |
| 735 | set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); |
| 736 | |
| 737 | /* |
| 738 | * Check for bit error, desync error,parity error,timeout error and |
| 739 | * receive overflow errors |
| 740 | */ |
| 741 | if (errors) { |
| 742 | ret = davinci_spi_check_error(dspi, errors); |
| 743 | WARN(!ret, "%s: error reported but no error found!\n", |
| 744 | dev_name(&spi->dev)); |
| 745 | return ret; |
| 746 | } |
| 747 | |
| 748 | if (dspi->rcount != 0 || dspi->wcount != 0) { |
| 749 | dev_err(&spi->dev, "SPI data transfer error\n"); |
| 750 | return -EIO; |
| 751 | } |
| 752 | |
| 753 | return t->len; |
| 754 | |
| 755 | err_desc: |
| 756 | dma_unmap_single(&spi->dev, t->tx_dma, t->len, DMA_TO_DEVICE); |
| 757 | err_tx_map: |
| 758 | dma_unmap_single(&spi->dev, t->rx_dma, t->len, DMA_FROM_DEVICE); |
| 759 | err_rx_map: |
| 760 | kfree(dummy_buf); |
| 761 | err_alloc_dummy_buf: |
| 762 | return ret; |
| 763 | } |
| 764 | |
| 765 | /** |
| 766 | * dummy_thread_fn - dummy thread function |
| 767 | * @irq: IRQ number for this SPI Master |
| 768 | * @context_data: structure for SPI Master controller davinci_spi |
| 769 | * |
| 770 | * This is to satisfy the request_threaded_irq() API so that the irq |
| 771 | * handler is called in interrupt context. |
| 772 | */ |
| 773 | static irqreturn_t dummy_thread_fn(s32 irq, void *data) |
| 774 | { |
| 775 | return IRQ_HANDLED; |
| 776 | } |
| 777 | |
| 778 | /** |
| 779 | * davinci_spi_irq - Interrupt handler for SPI Master Controller |
| 780 | * @irq: IRQ number for this SPI Master |
| 781 | * @context_data: structure for SPI Master controller davinci_spi |
| 782 | * |
| 783 | * ISR will determine that interrupt arrives either for READ or WRITE command. |
| 784 | * According to command it will do the appropriate action. It will check |
| 785 | * transfer length and if it is not zero then dispatch transfer command again. |
| 786 | * If transfer length is zero then it will indicate the COMPLETION so that |
| 787 | * davinci_spi_bufs function can go ahead. |
| 788 | */ |
| 789 | static irqreturn_t davinci_spi_irq(s32 irq, void *data) |
| 790 | { |
| 791 | struct davinci_spi *dspi = data; |
| 792 | int status; |
| 793 | |
| 794 | status = davinci_spi_process_events(dspi); |
| 795 | if (unlikely(status != 0)) |
| 796 | clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); |
| 797 | |
| 798 | if ((!dspi->rcount && !dspi->wcount) || status) |
| 799 | complete(&dspi->done); |
| 800 | |
| 801 | return IRQ_HANDLED; |
| 802 | } |
| 803 | |
| 804 | static int davinci_spi_request_dma(struct davinci_spi *dspi) |
| 805 | { |
| 806 | dma_cap_mask_t mask; |
| 807 | struct device *sdev = dspi->bitbang.master->dev.parent; |
| 808 | int r; |
| 809 | |
| 810 | dma_cap_zero(mask); |
| 811 | dma_cap_set(DMA_SLAVE, mask); |
| 812 | |
| 813 | dspi->dma_rx = dma_request_channel(mask, edma_filter_fn, |
| 814 | &dspi->dma_rx_chnum); |
| 815 | if (!dspi->dma_rx) { |
| 816 | dev_err(sdev, "request RX DMA channel failed\n"); |
| 817 | r = -ENODEV; |
| 818 | goto rx_dma_failed; |
| 819 | } |
| 820 | |
| 821 | dspi->dma_tx = dma_request_channel(mask, edma_filter_fn, |
| 822 | &dspi->dma_tx_chnum); |
| 823 | if (!dspi->dma_tx) { |
| 824 | dev_err(sdev, "request TX DMA channel failed\n"); |
| 825 | r = -ENODEV; |
| 826 | goto tx_dma_failed; |
| 827 | } |
| 828 | |
| 829 | return 0; |
| 830 | |
| 831 | tx_dma_failed: |
| 832 | dma_release_channel(dspi->dma_rx); |
| 833 | rx_dma_failed: |
| 834 | return r; |
| 835 | } |
| 836 | |
| 837 | #if defined(CONFIG_OF) |
| 838 | |
| 839 | /* OF SPI data structure */ |
| 840 | struct davinci_spi_of_data { |
| 841 | u8 version; |
| 842 | u8 prescaler_limit; |
| 843 | }; |
| 844 | |
| 845 | static const struct davinci_spi_of_data dm6441_spi_data = { |
| 846 | .version = SPI_VERSION_1, |
| 847 | .prescaler_limit = 2, |
| 848 | }; |
| 849 | |
| 850 | static const struct davinci_spi_of_data da830_spi_data = { |
| 851 | .version = SPI_VERSION_2, |
| 852 | .prescaler_limit = 2, |
| 853 | }; |
| 854 | |
| 855 | static const struct davinci_spi_of_data keystone_spi_data = { |
| 856 | .version = SPI_VERSION_1, |
| 857 | .prescaler_limit = 0, |
| 858 | }; |
| 859 | |
| 860 | static const struct of_device_id davinci_spi_of_match[] = { |
| 861 | { |
| 862 | .compatible = "ti,dm6441-spi", |
| 863 | .data = &dm6441_spi_data, |
| 864 | }, |
| 865 | { |
| 866 | .compatible = "ti,da830-spi", |
| 867 | .data = &da830_spi_data, |
| 868 | }, |
| 869 | { |
| 870 | .compatible = "ti,keystone-spi", |
| 871 | .data = &keystone_spi_data, |
| 872 | }, |
| 873 | { }, |
| 874 | }; |
| 875 | MODULE_DEVICE_TABLE(of, davinci_spi_of_match); |
| 876 | |
| 877 | /** |
| 878 | * spi_davinci_get_pdata - Get platform data from DTS binding |
| 879 | * @pdev: ptr to platform data |
| 880 | * @dspi: ptr to driver data |
| 881 | * |
| 882 | * Parses and populates pdata in dspi from device tree bindings. |
| 883 | * |
| 884 | * NOTE: Not all platform data params are supported currently. |
| 885 | */ |
| 886 | static int spi_davinci_get_pdata(struct platform_device *pdev, |
| 887 | struct davinci_spi *dspi) |
| 888 | { |
| 889 | struct device_node *node = pdev->dev.of_node; |
| 890 | struct davinci_spi_of_data *spi_data; |
| 891 | struct davinci_spi_platform_data *pdata; |
| 892 | unsigned int num_cs, intr_line = 0; |
| 893 | const struct of_device_id *match; |
| 894 | |
| 895 | pdata = &dspi->pdata; |
| 896 | |
| 897 | match = of_match_device(davinci_spi_of_match, &pdev->dev); |
| 898 | if (!match) |
| 899 | return -ENODEV; |
| 900 | |
| 901 | spi_data = (struct davinci_spi_of_data *)match->data; |
| 902 | |
| 903 | pdata->version = spi_data->version; |
| 904 | pdata->prescaler_limit = spi_data->prescaler_limit; |
| 905 | /* |
| 906 | * default num_cs is 1 and all chipsel are internal to the chip |
| 907 | * indicated by chip_sel being NULL or cs_gpios being NULL or |
| 908 | * set to -ENOENT. num-cs includes internal as well as gpios. |
| 909 | * indicated by chip_sel being NULL. GPIO based CS is not |
| 910 | * supported yet in DT bindings. |
| 911 | */ |
| 912 | num_cs = 1; |
| 913 | of_property_read_u32(node, "num-cs", &num_cs); |
| 914 | pdata->num_chipselect = num_cs; |
| 915 | of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line); |
| 916 | pdata->intr_line = intr_line; |
| 917 | return 0; |
| 918 | } |
| 919 | #else |
| 920 | static struct davinci_spi_platform_data |
| 921 | *spi_davinci_get_pdata(struct platform_device *pdev, |
| 922 | struct davinci_spi *dspi) |
| 923 | { |
| 924 | return -ENODEV; |
| 925 | } |
| 926 | #endif |
| 927 | |
| 928 | /** |
| 929 | * davinci_spi_probe - probe function for SPI Master Controller |
| 930 | * @pdev: platform_device structure which contains plateform specific data |
| 931 | * |
| 932 | * According to Linux Device Model this function will be invoked by Linux |
| 933 | * with platform_device struct which contains the device specific info. |
| 934 | * This function will map the SPI controller's memory, register IRQ, |
| 935 | * Reset SPI controller and setting its registers to default value. |
| 936 | * It will invoke spi_bitbang_start to create work queue so that client driver |
| 937 | * can register transfer method to work queue. |
| 938 | */ |
| 939 | static int davinci_spi_probe(struct platform_device *pdev) |
| 940 | { |
| 941 | struct spi_master *master; |
| 942 | struct davinci_spi *dspi; |
| 943 | struct davinci_spi_platform_data *pdata; |
| 944 | struct resource *r; |
| 945 | resource_size_t dma_rx_chan = SPI_NO_RESOURCE; |
| 946 | resource_size_t dma_tx_chan = SPI_NO_RESOURCE; |
| 947 | int ret = 0; |
| 948 | u32 spipc0; |
| 949 | |
| 950 | master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi)); |
| 951 | if (master == NULL) { |
| 952 | ret = -ENOMEM; |
| 953 | goto err; |
| 954 | } |
| 955 | |
| 956 | platform_set_drvdata(pdev, master); |
| 957 | |
| 958 | dspi = spi_master_get_devdata(master); |
| 959 | |
| 960 | if (dev_get_platdata(&pdev->dev)) { |
| 961 | pdata = dev_get_platdata(&pdev->dev); |
| 962 | dspi->pdata = *pdata; |
| 963 | } else { |
| 964 | /* update dspi pdata with that from the DT */ |
| 965 | ret = spi_davinci_get_pdata(pdev, dspi); |
| 966 | if (ret < 0) |
| 967 | goto free_master; |
| 968 | } |
| 969 | |
| 970 | /* pdata in dspi is now updated and point pdata to that */ |
| 971 | pdata = &dspi->pdata; |
| 972 | |
| 973 | dspi->bytes_per_word = devm_kzalloc(&pdev->dev, |
| 974 | sizeof(*dspi->bytes_per_word) * |
| 975 | pdata->num_chipselect, GFP_KERNEL); |
| 976 | if (dspi->bytes_per_word == NULL) { |
| 977 | ret = -ENOMEM; |
| 978 | goto free_master; |
| 979 | } |
| 980 | |
| 981 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 982 | if (r == NULL) { |
| 983 | ret = -ENOENT; |
| 984 | goto free_master; |
| 985 | } |
| 986 | |
| 987 | dspi->pbase = r->start; |
| 988 | |
| 989 | dspi->base = devm_ioremap_resource(&pdev->dev, r); |
| 990 | if (IS_ERR(dspi->base)) { |
| 991 | ret = PTR_ERR(dspi->base); |
| 992 | goto free_master; |
| 993 | } |
| 994 | |
| 995 | dspi->irq = platform_get_irq(pdev, 0); |
| 996 | if (dspi->irq <= 0) { |
| 997 | ret = -EINVAL; |
| 998 | goto free_master; |
| 999 | } |
| 1000 | |
| 1001 | ret = devm_request_threaded_irq(&pdev->dev, dspi->irq, davinci_spi_irq, |
| 1002 | dummy_thread_fn, 0, dev_name(&pdev->dev), dspi); |
| 1003 | if (ret) |
| 1004 | goto free_master; |
| 1005 | |
| 1006 | dspi->bitbang.master = master; |
| 1007 | |
| 1008 | dspi->clk = devm_clk_get(&pdev->dev, NULL); |
| 1009 | if (IS_ERR(dspi->clk)) { |
| 1010 | ret = -ENODEV; |
| 1011 | goto free_master; |
| 1012 | } |
| 1013 | clk_prepare_enable(dspi->clk); |
| 1014 | |
| 1015 | master->dev.of_node = pdev->dev.of_node; |
| 1016 | master->bus_num = pdev->id; |
| 1017 | master->num_chipselect = pdata->num_chipselect; |
| 1018 | master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16); |
| 1019 | master->setup = davinci_spi_setup; |
| 1020 | master->cleanup = davinci_spi_cleanup; |
| 1021 | |
| 1022 | dspi->bitbang.chipselect = davinci_spi_chipselect; |
| 1023 | dspi->bitbang.setup_transfer = davinci_spi_setup_transfer; |
| 1024 | dspi->prescaler_limit = pdata->prescaler_limit; |
| 1025 | dspi->version = pdata->version; |
| 1026 | |
| 1027 | dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP; |
| 1028 | if (dspi->version == SPI_VERSION_2) |
| 1029 | dspi->bitbang.flags |= SPI_READY; |
| 1030 | |
| 1031 | if (pdev->dev.of_node) { |
| 1032 | int i; |
| 1033 | |
| 1034 | for (i = 0; i < pdata->num_chipselect; i++) { |
| 1035 | int cs_gpio = of_get_named_gpio(pdev->dev.of_node, |
| 1036 | "cs-gpios", i); |
| 1037 | |
| 1038 | if (cs_gpio == -EPROBE_DEFER) { |
| 1039 | ret = cs_gpio; |
| 1040 | goto free_clk; |
| 1041 | } |
| 1042 | |
| 1043 | if (gpio_is_valid(cs_gpio)) { |
| 1044 | ret = devm_gpio_request(&pdev->dev, cs_gpio, |
| 1045 | dev_name(&pdev->dev)); |
| 1046 | if (ret) |
| 1047 | goto free_clk; |
| 1048 | } |
| 1049 | } |
| 1050 | } |
| 1051 | |
| 1052 | r = platform_get_resource(pdev, IORESOURCE_DMA, 0); |
| 1053 | if (r) |
| 1054 | dma_rx_chan = r->start; |
| 1055 | r = platform_get_resource(pdev, IORESOURCE_DMA, 1); |
| 1056 | if (r) |
| 1057 | dma_tx_chan = r->start; |
| 1058 | |
| 1059 | dspi->bitbang.txrx_bufs = davinci_spi_bufs; |
| 1060 | if (dma_rx_chan != SPI_NO_RESOURCE && |
| 1061 | dma_tx_chan != SPI_NO_RESOURCE) { |
| 1062 | dspi->dma_rx_chnum = dma_rx_chan; |
| 1063 | dspi->dma_tx_chnum = dma_tx_chan; |
| 1064 | |
| 1065 | ret = davinci_spi_request_dma(dspi); |
| 1066 | if (ret) |
| 1067 | goto free_clk; |
| 1068 | |
| 1069 | dev_info(&pdev->dev, "DMA: supported\n"); |
| 1070 | dev_info(&pdev->dev, "DMA: RX channel: %pa, TX channel: %pa, event queue: %d\n", |
| 1071 | &dma_rx_chan, &dma_tx_chan, |
| 1072 | pdata->dma_event_q); |
| 1073 | } |
| 1074 | |
| 1075 | dspi->get_rx = davinci_spi_rx_buf_u8; |
| 1076 | dspi->get_tx = davinci_spi_tx_buf_u8; |
| 1077 | |
| 1078 | init_completion(&dspi->done); |
| 1079 | |
| 1080 | /* Reset In/OUT SPI module */ |
| 1081 | iowrite32(0, dspi->base + SPIGCR0); |
| 1082 | udelay(100); |
| 1083 | iowrite32(1, dspi->base + SPIGCR0); |
| 1084 | |
| 1085 | /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */ |
| 1086 | spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK; |
| 1087 | iowrite32(spipc0, dspi->base + SPIPC0); |
| 1088 | |
| 1089 | if (pdata->intr_line) |
| 1090 | iowrite32(SPI_INTLVL_1, dspi->base + SPILVL); |
| 1091 | else |
| 1092 | iowrite32(SPI_INTLVL_0, dspi->base + SPILVL); |
| 1093 | |
| 1094 | iowrite32(CS_DEFAULT, dspi->base + SPIDEF); |
| 1095 | |
| 1096 | /* master mode default */ |
| 1097 | set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK); |
| 1098 | set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK); |
| 1099 | set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); |
| 1100 | |
| 1101 | ret = spi_bitbang_start(&dspi->bitbang); |
| 1102 | if (ret) |
| 1103 | goto free_dma; |
| 1104 | |
| 1105 | dev_info(&pdev->dev, "Controller at 0x%p\n", dspi->base); |
| 1106 | |
| 1107 | return ret; |
| 1108 | |
| 1109 | free_dma: |
| 1110 | dma_release_channel(dspi->dma_rx); |
| 1111 | dma_release_channel(dspi->dma_tx); |
| 1112 | free_clk: |
| 1113 | clk_disable_unprepare(dspi->clk); |
| 1114 | free_master: |
| 1115 | spi_master_put(master); |
| 1116 | err: |
| 1117 | return ret; |
| 1118 | } |
| 1119 | |
| 1120 | /** |
| 1121 | * davinci_spi_remove - remove function for SPI Master Controller |
| 1122 | * @pdev: platform_device structure which contains plateform specific data |
| 1123 | * |
| 1124 | * This function will do the reverse action of davinci_spi_probe function |
| 1125 | * It will free the IRQ and SPI controller's memory region. |
| 1126 | * It will also call spi_bitbang_stop to destroy the work queue which was |
| 1127 | * created by spi_bitbang_start. |
| 1128 | */ |
| 1129 | static int davinci_spi_remove(struct platform_device *pdev) |
| 1130 | { |
| 1131 | struct davinci_spi *dspi; |
| 1132 | struct spi_master *master; |
| 1133 | |
| 1134 | master = platform_get_drvdata(pdev); |
| 1135 | dspi = spi_master_get_devdata(master); |
| 1136 | |
| 1137 | spi_bitbang_stop(&dspi->bitbang); |
| 1138 | |
| 1139 | clk_disable_unprepare(dspi->clk); |
| 1140 | spi_master_put(master); |
| 1141 | |
| 1142 | return 0; |
| 1143 | } |
| 1144 | |
| 1145 | static struct platform_driver davinci_spi_driver = { |
| 1146 | .driver = { |
| 1147 | .name = "spi_davinci", |
| 1148 | .of_match_table = of_match_ptr(davinci_spi_of_match), |
| 1149 | }, |
| 1150 | .probe = davinci_spi_probe, |
| 1151 | .remove = davinci_spi_remove, |
| 1152 | }; |
| 1153 | module_platform_driver(davinci_spi_driver); |
| 1154 | |
| 1155 | MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver"); |
| 1156 | MODULE_LICENSE("GPL"); |