Grant Likely | ca632f5 | 2011-06-06 01:16:30 -0600 | [diff] [blame] | 1 | /* |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 2 | * Copyright (c) 2009 Nuvoton technology. |
| 3 | * Wan ZongShun <mcuos.com@gmail.com> |
| 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 version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
Grant Likely | ca632f5 | 2011-06-06 01:16:30 -0600 | [diff] [blame] | 9 | */ |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/spinlock.h> |
| 13 | #include <linux/workqueue.h> |
| 14 | #include <linux/interrupt.h> |
| 15 | #include <linux/delay.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/err.h> |
| 18 | #include <linux/clk.h> |
| 19 | #include <linux/device.h> |
| 20 | #include <linux/platform_device.h> |
| 21 | #include <linux/gpio.h> |
| 22 | #include <linux/io.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 24 | |
| 25 | #include <linux/spi/spi.h> |
| 26 | #include <linux/spi/spi_bitbang.h> |
| 27 | |
| 28 | #include <mach/nuc900_spi.h> |
| 29 | |
| 30 | /* usi registers offset */ |
| 31 | #define USI_CNT 0x00 |
| 32 | #define USI_DIV 0x04 |
| 33 | #define USI_SSR 0x08 |
| 34 | #define USI_RX0 0x10 |
| 35 | #define USI_TX0 0x10 |
| 36 | |
| 37 | /* usi register bit */ |
| 38 | #define ENINT (0x01 << 17) |
| 39 | #define ENFLG (0x01 << 16) |
| 40 | #define TXNUM (0x03 << 8) |
| 41 | #define TXNEG (0x01 << 2) |
| 42 | #define RXNEG (0x01 << 1) |
| 43 | #define LSB (0x01 << 10) |
| 44 | #define SELECTLEV (0x01 << 2) |
| 45 | #define SELECTPOL (0x01 << 31) |
| 46 | #define SELECTSLAVE 0x01 |
| 47 | #define GOBUSY 0x01 |
| 48 | |
| 49 | struct nuc900_spi { |
| 50 | struct spi_bitbang bitbang; |
| 51 | struct completion done; |
| 52 | void __iomem *regs; |
| 53 | int irq; |
| 54 | int len; |
| 55 | int count; |
| 56 | const unsigned char *tx; |
| 57 | unsigned char *rx; |
| 58 | struct clk *clk; |
| 59 | struct resource *ioarea; |
| 60 | struct spi_master *master; |
| 61 | struct spi_device *curdev; |
| 62 | struct device *dev; |
| 63 | struct nuc900_spi_info *pdata; |
| 64 | spinlock_t lock; |
| 65 | struct resource *res; |
| 66 | }; |
| 67 | |
| 68 | static inline struct nuc900_spi *to_hw(struct spi_device *sdev) |
| 69 | { |
| 70 | return spi_master_get_devdata(sdev->master); |
| 71 | } |
| 72 | |
| 73 | static void nuc900_slave_select(struct spi_device *spi, unsigned int ssr) |
| 74 | { |
| 75 | struct nuc900_spi *hw = to_hw(spi); |
| 76 | unsigned int val; |
| 77 | unsigned int cs = spi->mode & SPI_CS_HIGH ? 1 : 0; |
| 78 | unsigned int cpol = spi->mode & SPI_CPOL ? 1 : 0; |
| 79 | unsigned long flags; |
| 80 | |
| 81 | spin_lock_irqsave(&hw->lock, flags); |
| 82 | |
| 83 | val = __raw_readl(hw->regs + USI_SSR); |
| 84 | |
| 85 | if (!cs) |
| 86 | val &= ~SELECTLEV; |
| 87 | else |
| 88 | val |= SELECTLEV; |
| 89 | |
| 90 | if (!ssr) |
| 91 | val &= ~SELECTSLAVE; |
| 92 | else |
| 93 | val |= SELECTSLAVE; |
| 94 | |
| 95 | __raw_writel(val, hw->regs + USI_SSR); |
| 96 | |
| 97 | val = __raw_readl(hw->regs + USI_CNT); |
| 98 | |
| 99 | if (!cpol) |
| 100 | val &= ~SELECTPOL; |
| 101 | else |
| 102 | val |= SELECTPOL; |
| 103 | |
| 104 | __raw_writel(val, hw->regs + USI_CNT); |
| 105 | |
| 106 | spin_unlock_irqrestore(&hw->lock, flags); |
| 107 | } |
| 108 | |
| 109 | static void nuc900_spi_chipsel(struct spi_device *spi, int value) |
| 110 | { |
| 111 | switch (value) { |
| 112 | case BITBANG_CS_INACTIVE: |
| 113 | nuc900_slave_select(spi, 0); |
| 114 | break; |
| 115 | |
| 116 | case BITBANG_CS_ACTIVE: |
| 117 | nuc900_slave_select(spi, 1); |
| 118 | break; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | static void nuc900_spi_setup_txnum(struct nuc900_spi *hw, |
| 123 | unsigned int txnum) |
| 124 | { |
| 125 | unsigned int val; |
| 126 | unsigned long flags; |
| 127 | |
| 128 | spin_lock_irqsave(&hw->lock, flags); |
| 129 | |
| 130 | val = __raw_readl(hw->regs + USI_CNT); |
| 131 | |
| 132 | if (!txnum) |
| 133 | val &= ~TXNUM; |
| 134 | else |
| 135 | val |= txnum << 0x08; |
| 136 | |
| 137 | __raw_writel(val, hw->regs + USI_CNT); |
| 138 | |
| 139 | spin_unlock_irqrestore(&hw->lock, flags); |
| 140 | |
| 141 | } |
| 142 | |
| 143 | static void nuc900_spi_setup_txbitlen(struct nuc900_spi *hw, |
| 144 | unsigned int txbitlen) |
| 145 | { |
| 146 | unsigned int val; |
| 147 | unsigned long flags; |
| 148 | |
| 149 | spin_lock_irqsave(&hw->lock, flags); |
| 150 | |
| 151 | val = __raw_readl(hw->regs + USI_CNT); |
| 152 | |
| 153 | val |= (txbitlen << 0x03); |
| 154 | |
| 155 | __raw_writel(val, hw->regs + USI_CNT); |
| 156 | |
| 157 | spin_unlock_irqrestore(&hw->lock, flags); |
| 158 | } |
| 159 | |
| 160 | static void nuc900_spi_gobusy(struct nuc900_spi *hw) |
| 161 | { |
| 162 | unsigned int val; |
| 163 | unsigned long flags; |
| 164 | |
| 165 | spin_lock_irqsave(&hw->lock, flags); |
| 166 | |
| 167 | val = __raw_readl(hw->regs + USI_CNT); |
| 168 | |
| 169 | val |= GOBUSY; |
| 170 | |
| 171 | __raw_writel(val, hw->regs + USI_CNT); |
| 172 | |
| 173 | spin_unlock_irqrestore(&hw->lock, flags); |
| 174 | } |
| 175 | |
| 176 | static int nuc900_spi_setupxfer(struct spi_device *spi, |
| 177 | struct spi_transfer *t) |
| 178 | { |
| 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | static int nuc900_spi_setup(struct spi_device *spi) |
| 183 | { |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | static inline unsigned int hw_txbyte(struct nuc900_spi *hw, int count) |
| 188 | { |
| 189 | return hw->tx ? hw->tx[count] : 0; |
| 190 | } |
| 191 | |
| 192 | static int nuc900_spi_txrx(struct spi_device *spi, struct spi_transfer *t) |
| 193 | { |
| 194 | struct nuc900_spi *hw = to_hw(spi); |
| 195 | |
| 196 | hw->tx = t->tx_buf; |
| 197 | hw->rx = t->rx_buf; |
| 198 | hw->len = t->len; |
| 199 | hw->count = 0; |
| 200 | |
| 201 | __raw_writel(hw_txbyte(hw, 0x0), hw->regs + USI_TX0); |
| 202 | |
| 203 | nuc900_spi_gobusy(hw); |
| 204 | |
| 205 | wait_for_completion(&hw->done); |
| 206 | |
| 207 | return hw->count; |
| 208 | } |
| 209 | |
| 210 | static irqreturn_t nuc900_spi_irq(int irq, void *dev) |
| 211 | { |
| 212 | struct nuc900_spi *hw = dev; |
| 213 | unsigned int status; |
| 214 | unsigned int count = hw->count; |
| 215 | |
| 216 | status = __raw_readl(hw->regs + USI_CNT); |
| 217 | __raw_writel(status, hw->regs + USI_CNT); |
| 218 | |
| 219 | if (status & ENFLG) { |
| 220 | hw->count++; |
| 221 | |
| 222 | if (hw->rx) |
| 223 | hw->rx[count] = __raw_readl(hw->regs + USI_RX0); |
| 224 | count++; |
| 225 | |
| 226 | if (count < hw->len) { |
| 227 | __raw_writel(hw_txbyte(hw, count), hw->regs + USI_TX0); |
| 228 | nuc900_spi_gobusy(hw); |
| 229 | } else { |
| 230 | complete(&hw->done); |
| 231 | } |
| 232 | |
| 233 | return IRQ_HANDLED; |
| 234 | } |
| 235 | |
| 236 | complete(&hw->done); |
| 237 | return IRQ_HANDLED; |
| 238 | } |
| 239 | |
| 240 | static void nuc900_tx_edge(struct nuc900_spi *hw, unsigned int edge) |
| 241 | { |
| 242 | unsigned int val; |
| 243 | unsigned long flags; |
| 244 | |
| 245 | spin_lock_irqsave(&hw->lock, flags); |
| 246 | |
| 247 | val = __raw_readl(hw->regs + USI_CNT); |
| 248 | |
| 249 | if (edge) |
| 250 | val |= TXNEG; |
| 251 | else |
| 252 | val &= ~TXNEG; |
| 253 | __raw_writel(val, hw->regs + USI_CNT); |
| 254 | |
| 255 | spin_unlock_irqrestore(&hw->lock, flags); |
| 256 | } |
| 257 | |
| 258 | static void nuc900_rx_edge(struct nuc900_spi *hw, unsigned int edge) |
| 259 | { |
| 260 | unsigned int val; |
| 261 | unsigned long flags; |
| 262 | |
| 263 | spin_lock_irqsave(&hw->lock, flags); |
| 264 | |
| 265 | val = __raw_readl(hw->regs + USI_CNT); |
| 266 | |
| 267 | if (edge) |
| 268 | val |= RXNEG; |
| 269 | else |
| 270 | val &= ~RXNEG; |
| 271 | __raw_writel(val, hw->regs + USI_CNT); |
| 272 | |
| 273 | spin_unlock_irqrestore(&hw->lock, flags); |
| 274 | } |
| 275 | |
| 276 | static void nuc900_send_first(struct nuc900_spi *hw, unsigned int lsb) |
| 277 | { |
| 278 | unsigned int val; |
| 279 | unsigned long flags; |
| 280 | |
| 281 | spin_lock_irqsave(&hw->lock, flags); |
| 282 | |
| 283 | val = __raw_readl(hw->regs + USI_CNT); |
| 284 | |
| 285 | if (lsb) |
| 286 | val |= LSB; |
| 287 | else |
| 288 | val &= ~LSB; |
| 289 | __raw_writel(val, hw->regs + USI_CNT); |
| 290 | |
| 291 | spin_unlock_irqrestore(&hw->lock, flags); |
| 292 | } |
| 293 | |
| 294 | static void nuc900_set_sleep(struct nuc900_spi *hw, unsigned int sleep) |
| 295 | { |
| 296 | unsigned int val; |
| 297 | unsigned long flags; |
| 298 | |
| 299 | spin_lock_irqsave(&hw->lock, flags); |
| 300 | |
| 301 | val = __raw_readl(hw->regs + USI_CNT); |
| 302 | |
| 303 | if (sleep) |
| 304 | val |= (sleep << 12); |
| 305 | else |
| 306 | val &= ~(0x0f << 12); |
| 307 | __raw_writel(val, hw->regs + USI_CNT); |
| 308 | |
| 309 | spin_unlock_irqrestore(&hw->lock, flags); |
| 310 | } |
| 311 | |
| 312 | static void nuc900_enable_int(struct nuc900_spi *hw) |
| 313 | { |
| 314 | unsigned int val; |
| 315 | unsigned long flags; |
| 316 | |
| 317 | spin_lock_irqsave(&hw->lock, flags); |
| 318 | |
| 319 | val = __raw_readl(hw->regs + USI_CNT); |
| 320 | |
| 321 | val |= ENINT; |
| 322 | |
| 323 | __raw_writel(val, hw->regs + USI_CNT); |
| 324 | |
| 325 | spin_unlock_irqrestore(&hw->lock, flags); |
| 326 | } |
| 327 | |
| 328 | static void nuc900_set_divider(struct nuc900_spi *hw) |
| 329 | { |
| 330 | __raw_writel(hw->pdata->divider, hw->regs + USI_DIV); |
| 331 | } |
| 332 | |
| 333 | static void nuc900_init_spi(struct nuc900_spi *hw) |
| 334 | { |
| 335 | clk_enable(hw->clk); |
| 336 | spin_lock_init(&hw->lock); |
| 337 | |
| 338 | nuc900_tx_edge(hw, hw->pdata->txneg); |
| 339 | nuc900_rx_edge(hw, hw->pdata->rxneg); |
| 340 | nuc900_send_first(hw, hw->pdata->lsb); |
| 341 | nuc900_set_sleep(hw, hw->pdata->sleep); |
| 342 | nuc900_spi_setup_txbitlen(hw, hw->pdata->txbitlen); |
| 343 | nuc900_spi_setup_txnum(hw, hw->pdata->txnum); |
| 344 | nuc900_set_divider(hw); |
| 345 | nuc900_enable_int(hw); |
| 346 | } |
| 347 | |
| 348 | static int __devinit nuc900_spi_probe(struct platform_device *pdev) |
| 349 | { |
| 350 | struct nuc900_spi *hw; |
| 351 | struct spi_master *master; |
| 352 | int err = 0; |
| 353 | |
| 354 | master = spi_alloc_master(&pdev->dev, sizeof(struct nuc900_spi)); |
| 355 | if (master == NULL) { |
| 356 | dev_err(&pdev->dev, "No memory for spi_master\n"); |
| 357 | err = -ENOMEM; |
| 358 | goto err_nomem; |
| 359 | } |
| 360 | |
| 361 | hw = spi_master_get_devdata(master); |
| 362 | memset(hw, 0, sizeof(struct nuc900_spi)); |
| 363 | |
| 364 | hw->master = spi_master_get(master); |
| 365 | hw->pdata = pdev->dev.platform_data; |
| 366 | hw->dev = &pdev->dev; |
| 367 | |
| 368 | if (hw->pdata == NULL) { |
| 369 | dev_err(&pdev->dev, "No platform data supplied\n"); |
| 370 | err = -ENOENT; |
| 371 | goto err_pdata; |
| 372 | } |
| 373 | |
| 374 | platform_set_drvdata(pdev, hw); |
| 375 | init_completion(&hw->done); |
| 376 | |
| 377 | master->mode_bits = SPI_MODE_0; |
| 378 | master->num_chipselect = hw->pdata->num_cs; |
| 379 | master->bus_num = hw->pdata->bus_num; |
| 380 | hw->bitbang.master = hw->master; |
| 381 | hw->bitbang.setup_transfer = nuc900_spi_setupxfer; |
| 382 | hw->bitbang.chipselect = nuc900_spi_chipsel; |
| 383 | hw->bitbang.txrx_bufs = nuc900_spi_txrx; |
| 384 | hw->bitbang.master->setup = nuc900_spi_setup; |
| 385 | |
| 386 | hw->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 387 | if (hw->res == NULL) { |
| 388 | dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); |
| 389 | err = -ENOENT; |
| 390 | goto err_pdata; |
| 391 | } |
| 392 | |
| 393 | hw->ioarea = request_mem_region(hw->res->start, |
| 394 | resource_size(hw->res), pdev->name); |
| 395 | |
| 396 | if (hw->ioarea == NULL) { |
| 397 | dev_err(&pdev->dev, "Cannot reserve region\n"); |
| 398 | err = -ENXIO; |
| 399 | goto err_pdata; |
| 400 | } |
| 401 | |
| 402 | hw->regs = ioremap(hw->res->start, resource_size(hw->res)); |
| 403 | if (hw->regs == NULL) { |
| 404 | dev_err(&pdev->dev, "Cannot map IO\n"); |
| 405 | err = -ENXIO; |
| 406 | goto err_iomap; |
| 407 | } |
| 408 | |
| 409 | hw->irq = platform_get_irq(pdev, 0); |
| 410 | if (hw->irq < 0) { |
| 411 | dev_err(&pdev->dev, "No IRQ specified\n"); |
| 412 | err = -ENOENT; |
| 413 | goto err_irq; |
| 414 | } |
| 415 | |
| 416 | err = request_irq(hw->irq, nuc900_spi_irq, 0, pdev->name, hw); |
| 417 | if (err) { |
| 418 | dev_err(&pdev->dev, "Cannot claim IRQ\n"); |
| 419 | goto err_irq; |
| 420 | } |
| 421 | |
| 422 | hw->clk = clk_get(&pdev->dev, "spi"); |
| 423 | if (IS_ERR(hw->clk)) { |
| 424 | dev_err(&pdev->dev, "No clock for device\n"); |
| 425 | err = PTR_ERR(hw->clk); |
| 426 | goto err_clk; |
| 427 | } |
| 428 | |
Axel Lin | 97371fa | 2011-11-25 00:23:28 +0100 | [diff] [blame] | 429 | mfp_set_groupg(&pdev->dev, NULL); |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 430 | nuc900_init_spi(hw); |
| 431 | |
| 432 | err = spi_bitbang_start(&hw->bitbang); |
| 433 | if (err) { |
| 434 | dev_err(&pdev->dev, "Failed to register SPI master\n"); |
| 435 | goto err_register; |
| 436 | } |
| 437 | |
| 438 | return 0; |
| 439 | |
| 440 | err_register: |
| 441 | clk_disable(hw->clk); |
| 442 | clk_put(hw->clk); |
| 443 | err_clk: |
| 444 | free_irq(hw->irq, hw); |
| 445 | err_irq: |
| 446 | iounmap(hw->regs); |
| 447 | err_iomap: |
| 448 | release_mem_region(hw->res->start, resource_size(hw->res)); |
| 449 | kfree(hw->ioarea); |
| 450 | err_pdata: |
Joe Perches | bc3f67a | 2010-11-14 19:04:47 -0800 | [diff] [blame] | 451 | spi_master_put(hw->master); |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 452 | |
| 453 | err_nomem: |
| 454 | return err; |
| 455 | } |
| 456 | |
| 457 | static int __devexit nuc900_spi_remove(struct platform_device *dev) |
| 458 | { |
| 459 | struct nuc900_spi *hw = platform_get_drvdata(dev); |
| 460 | |
| 461 | free_irq(hw->irq, hw); |
| 462 | |
| 463 | platform_set_drvdata(dev, NULL); |
| 464 | |
Axel Lin | 708a7e4 | 2011-05-15 07:33:28 +0800 | [diff] [blame] | 465 | spi_bitbang_stop(&hw->bitbang); |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 466 | |
| 467 | clk_disable(hw->clk); |
| 468 | clk_put(hw->clk); |
| 469 | |
| 470 | iounmap(hw->regs); |
| 471 | |
| 472 | release_mem_region(hw->res->start, resource_size(hw->res)); |
| 473 | kfree(hw->ioarea); |
| 474 | |
| 475 | spi_master_put(hw->master); |
| 476 | return 0; |
| 477 | } |
| 478 | |
| 479 | static struct platform_driver nuc900_spi_driver = { |
| 480 | .probe = nuc900_spi_probe, |
| 481 | .remove = __devexit_p(nuc900_spi_remove), |
| 482 | .driver = { |
| 483 | .name = "nuc900-spi", |
| 484 | .owner = THIS_MODULE, |
| 485 | }, |
| 486 | }; |
Grant Likely | 940ab88 | 2011-10-05 11:29:49 -0600 | [diff] [blame] | 487 | module_platform_driver(nuc900_spi_driver); |
Wan ZongShun | 30eaed0 | 2009-12-01 14:29:20 +0000 | [diff] [blame] | 488 | |
| 489 | MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>"); |
| 490 | MODULE_DESCRIPTION("nuc900 spi driver!"); |
| 491 | MODULE_LICENSE("GPL"); |
| 492 | MODULE_ALIAS("platform:nuc900-spi"); |