Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Specific bus support for PMC-TWI compliant implementation on MSP71xx. |
| 3 | * |
| 4 | * Copyright 2005-2007 PMC-Sierra, Inc. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License as published by the |
| 8 | * Free Software Foundation; either version 2 of the License, or (at your |
| 9 | * option) any later version. |
| 10 | * |
| 11 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 12 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 13 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN |
| 14 | * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 15 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 16 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| 17 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
| 18 | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 19 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 20 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License along |
| 23 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 24 | * 675 Mass Ave, Cambridge, MA 02139, USA. |
| 25 | */ |
| 26 | |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/init.h> |
| 30 | #include <linux/platform_device.h> |
| 31 | #include <linux/i2c.h> |
| 32 | #include <linux/interrupt.h> |
| 33 | #include <linux/completion.h> |
| 34 | #include <linux/mutex.h> |
| 35 | #include <linux/delay.h> |
| 36 | #include <asm/io.h> |
| 37 | |
| 38 | #define DRV_NAME "pmcmsptwi" |
| 39 | |
| 40 | #define MSP_TWI_SF_CLK_REG_OFFSET 0x00 |
| 41 | #define MSP_TWI_HS_CLK_REG_OFFSET 0x04 |
| 42 | #define MSP_TWI_CFG_REG_OFFSET 0x08 |
| 43 | #define MSP_TWI_CMD_REG_OFFSET 0x0c |
| 44 | #define MSP_TWI_ADD_REG_OFFSET 0x10 |
| 45 | #define MSP_TWI_DAT_0_REG_OFFSET 0x14 |
| 46 | #define MSP_TWI_DAT_1_REG_OFFSET 0x18 |
| 47 | #define MSP_TWI_INT_STS_REG_OFFSET 0x1c |
| 48 | #define MSP_TWI_INT_MSK_REG_OFFSET 0x20 |
| 49 | #define MSP_TWI_BUSY_REG_OFFSET 0x24 |
| 50 | |
| 51 | #define MSP_TWI_INT_STS_DONE (1 << 0) |
| 52 | #define MSP_TWI_INT_STS_LOST_ARBITRATION (1 << 1) |
| 53 | #define MSP_TWI_INT_STS_NO_RESPONSE (1 << 2) |
| 54 | #define MSP_TWI_INT_STS_DATA_COLLISION (1 << 3) |
| 55 | #define MSP_TWI_INT_STS_BUSY (1 << 4) |
| 56 | #define MSP_TWI_INT_STS_ALL 0x1f |
| 57 | |
| 58 | #define MSP_MAX_BYTES_PER_RW 8 |
| 59 | #define MSP_MAX_POLL 5 |
| 60 | #define MSP_POLL_DELAY 10 |
| 61 | #define MSP_IRQ_TIMEOUT (MSP_MAX_POLL * MSP_POLL_DELAY) |
| 62 | |
| 63 | /* IO Operation macros */ |
| 64 | #define pmcmsptwi_readl __raw_readl |
| 65 | #define pmcmsptwi_writel __raw_writel |
| 66 | |
| 67 | /* TWI command type */ |
| 68 | enum pmcmsptwi_cmd_type { |
| 69 | MSP_TWI_CMD_WRITE = 0, /* Write only */ |
| 70 | MSP_TWI_CMD_READ = 1, /* Read only */ |
| 71 | MSP_TWI_CMD_WRITE_READ = 2, /* Write then Read */ |
| 72 | }; |
| 73 | |
| 74 | /* The possible results of the xferCmd */ |
| 75 | enum pmcmsptwi_xfer_result { |
| 76 | MSP_TWI_XFER_OK = 0, |
| 77 | MSP_TWI_XFER_TIMEOUT, |
| 78 | MSP_TWI_XFER_BUSY, |
| 79 | MSP_TWI_XFER_DATA_COLLISION, |
| 80 | MSP_TWI_XFER_NO_RESPONSE, |
| 81 | MSP_TWI_XFER_LOST_ARBITRATION, |
| 82 | }; |
| 83 | |
| 84 | /* Corresponds to a PMCTWI clock configuration register */ |
| 85 | struct pmcmsptwi_clock { |
| 86 | u8 filter; /* Bits 15:12, default = 0x03 */ |
| 87 | u16 clock; /* Bits 9:0, default = 0x001f */ |
| 88 | }; |
| 89 | |
| 90 | struct pmcmsptwi_clockcfg { |
| 91 | struct pmcmsptwi_clock standard; /* The standard/fast clock config */ |
| 92 | struct pmcmsptwi_clock highspeed; /* The highspeed clock config */ |
| 93 | }; |
| 94 | |
| 95 | /* Corresponds to the main TWI configuration register */ |
| 96 | struct pmcmsptwi_cfg { |
| 97 | u8 arbf; /* Bits 15:12, default=0x03 */ |
| 98 | u8 nak; /* Bits 11:8, default=0x03 */ |
| 99 | u8 add10; /* Bit 7, default=0x00 */ |
| 100 | u8 mst_code; /* Bits 6:4, default=0x00 */ |
| 101 | u8 arb; /* Bit 1, default=0x01 */ |
| 102 | u8 highspeed; /* Bit 0, default=0x00 */ |
| 103 | }; |
| 104 | |
| 105 | /* A single pmctwi command to issue */ |
| 106 | struct pmcmsptwi_cmd { |
| 107 | u16 addr; /* The slave address (7 or 10 bits) */ |
| 108 | enum pmcmsptwi_cmd_type type; /* The command type */ |
| 109 | u8 write_len; /* Number of bytes in the write buffer */ |
| 110 | u8 read_len; /* Number of bytes in the read buffer */ |
| 111 | u8 *write_data; /* Buffer of characters to send */ |
| 112 | u8 *read_data; /* Buffer to fill with incoming data */ |
| 113 | }; |
| 114 | |
| 115 | /* The private data */ |
| 116 | struct pmcmsptwi_data { |
| 117 | void __iomem *iobase; /* iomapped base for IO */ |
| 118 | int irq; /* IRQ to use (0 disables) */ |
| 119 | struct completion wait; /* Completion for xfer */ |
| 120 | struct mutex lock; /* Used for threadsafeness */ |
| 121 | enum pmcmsptwi_xfer_result last_result; /* result of last xfer */ |
| 122 | }; |
| 123 | |
| 124 | /* The default settings */ |
Tobias Klauser | 305183f | 2008-02-24 20:03:42 +0100 | [diff] [blame] | 125 | static const struct pmcmsptwi_clockcfg pmcmsptwi_defclockcfg = { |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 126 | .standard = { |
| 127 | .filter = 0x3, |
| 128 | .clock = 0x1f, |
| 129 | }, |
| 130 | .highspeed = { |
| 131 | .filter = 0x3, |
| 132 | .clock = 0x1f, |
| 133 | }, |
| 134 | }; |
| 135 | |
Tobias Klauser | 305183f | 2008-02-24 20:03:42 +0100 | [diff] [blame] | 136 | static const struct pmcmsptwi_cfg pmcmsptwi_defcfg = { |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 137 | .arbf = 0x03, |
| 138 | .nak = 0x03, |
| 139 | .add10 = 0x00, |
| 140 | .mst_code = 0x00, |
| 141 | .arb = 0x01, |
| 142 | .highspeed = 0x00, |
| 143 | }; |
| 144 | |
| 145 | static struct pmcmsptwi_data pmcmsptwi_data; |
| 146 | |
| 147 | static struct i2c_adapter pmcmsptwi_adapter; |
| 148 | |
| 149 | /* inline helper functions */ |
| 150 | static inline u32 pmcmsptwi_clock_to_reg( |
| 151 | const struct pmcmsptwi_clock *clock) |
| 152 | { |
| 153 | return ((clock->filter & 0xf) << 12) | (clock->clock & 0x03ff); |
| 154 | } |
| 155 | |
| 156 | static inline void pmcmsptwi_reg_to_clock( |
| 157 | u32 reg, struct pmcmsptwi_clock *clock) |
| 158 | { |
| 159 | clock->filter = (reg >> 12) & 0xf; |
| 160 | clock->clock = reg & 0x03ff; |
| 161 | } |
| 162 | |
| 163 | static inline u32 pmcmsptwi_cfg_to_reg(const struct pmcmsptwi_cfg *cfg) |
| 164 | { |
| 165 | return ((cfg->arbf & 0xf) << 12) | |
| 166 | ((cfg->nak & 0xf) << 8) | |
| 167 | ((cfg->add10 & 0x1) << 7) | |
| 168 | ((cfg->mst_code & 0x7) << 4) | |
| 169 | ((cfg->arb & 0x1) << 1) | |
| 170 | (cfg->highspeed & 0x1); |
| 171 | } |
| 172 | |
| 173 | static inline void pmcmsptwi_reg_to_cfg(u32 reg, struct pmcmsptwi_cfg *cfg) |
| 174 | { |
| 175 | cfg->arbf = (reg >> 12) & 0xf; |
| 176 | cfg->nak = (reg >> 8) & 0xf; |
| 177 | cfg->add10 = (reg >> 7) & 0x1; |
| 178 | cfg->mst_code = (reg >> 4) & 0x7; |
| 179 | cfg->arb = (reg >> 1) & 0x1; |
| 180 | cfg->highspeed = reg & 0x1; |
| 181 | } |
| 182 | |
| 183 | /* |
| 184 | * Sets the current clock configuration |
| 185 | */ |
| 186 | static void pmcmsptwi_set_clock_config(const struct pmcmsptwi_clockcfg *cfg, |
| 187 | struct pmcmsptwi_data *data) |
| 188 | { |
| 189 | mutex_lock(&data->lock); |
| 190 | pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->standard), |
| 191 | data->iobase + MSP_TWI_SF_CLK_REG_OFFSET); |
| 192 | pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->highspeed), |
| 193 | data->iobase + MSP_TWI_HS_CLK_REG_OFFSET); |
| 194 | mutex_unlock(&data->lock); |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * Gets the current TWI bus configuration |
| 199 | */ |
| 200 | static void pmcmsptwi_get_twi_config(struct pmcmsptwi_cfg *cfg, |
| 201 | struct pmcmsptwi_data *data) |
| 202 | { |
| 203 | mutex_lock(&data->lock); |
| 204 | pmcmsptwi_reg_to_cfg(pmcmsptwi_readl( |
| 205 | data->iobase + MSP_TWI_CFG_REG_OFFSET), cfg); |
| 206 | mutex_unlock(&data->lock); |
| 207 | } |
| 208 | |
| 209 | /* |
| 210 | * Sets the current TWI bus configuration |
| 211 | */ |
| 212 | static void pmcmsptwi_set_twi_config(const struct pmcmsptwi_cfg *cfg, |
| 213 | struct pmcmsptwi_data *data) |
| 214 | { |
| 215 | mutex_lock(&data->lock); |
| 216 | pmcmsptwi_writel(pmcmsptwi_cfg_to_reg(cfg), |
| 217 | data->iobase + MSP_TWI_CFG_REG_OFFSET); |
| 218 | mutex_unlock(&data->lock); |
| 219 | } |
| 220 | |
| 221 | /* |
| 222 | * Parses the 'int_sts' register and returns a well-defined error code |
| 223 | */ |
| 224 | static enum pmcmsptwi_xfer_result pmcmsptwi_get_result(u32 reg) |
| 225 | { |
| 226 | if (reg & MSP_TWI_INT_STS_LOST_ARBITRATION) { |
| 227 | dev_dbg(&pmcmsptwi_adapter.dev, |
| 228 | "Result: Lost arbitration\n"); |
| 229 | return MSP_TWI_XFER_LOST_ARBITRATION; |
| 230 | } else if (reg & MSP_TWI_INT_STS_NO_RESPONSE) { |
| 231 | dev_dbg(&pmcmsptwi_adapter.dev, |
| 232 | "Result: No response\n"); |
| 233 | return MSP_TWI_XFER_NO_RESPONSE; |
| 234 | } else if (reg & MSP_TWI_INT_STS_DATA_COLLISION) { |
| 235 | dev_dbg(&pmcmsptwi_adapter.dev, |
| 236 | "Result: Data collision\n"); |
| 237 | return MSP_TWI_XFER_DATA_COLLISION; |
| 238 | } else if (reg & MSP_TWI_INT_STS_BUSY) { |
| 239 | dev_dbg(&pmcmsptwi_adapter.dev, |
| 240 | "Result: Bus busy\n"); |
| 241 | return MSP_TWI_XFER_BUSY; |
| 242 | } |
| 243 | |
| 244 | dev_dbg(&pmcmsptwi_adapter.dev, "Result: Operation succeeded\n"); |
| 245 | return MSP_TWI_XFER_OK; |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * In interrupt mode, handle the interrupt. |
| 250 | * NOTE: Assumes data->lock is held. |
| 251 | */ |
| 252 | static irqreturn_t pmcmsptwi_interrupt(int irq, void *ptr) |
| 253 | { |
| 254 | struct pmcmsptwi_data *data = ptr; |
| 255 | |
| 256 | u32 reason = pmcmsptwi_readl(data->iobase + |
| 257 | MSP_TWI_INT_STS_REG_OFFSET); |
| 258 | pmcmsptwi_writel(reason, data->iobase + MSP_TWI_INT_STS_REG_OFFSET); |
| 259 | |
| 260 | dev_dbg(&pmcmsptwi_adapter.dev, "Got interrupt 0x%08x\n", reason); |
| 261 | if (!(reason & MSP_TWI_INT_STS_DONE)) |
| 262 | return IRQ_NONE; |
| 263 | |
| 264 | data->last_result = pmcmsptwi_get_result(reason); |
| 265 | complete(&data->wait); |
| 266 | |
| 267 | return IRQ_HANDLED; |
| 268 | } |
| 269 | |
| 270 | /* |
| 271 | * Probe for and register the device and return 0 if there is one. |
| 272 | */ |
| 273 | static int __devinit pmcmsptwi_probe(struct platform_device *pldev) |
| 274 | { |
| 275 | struct resource *res; |
| 276 | int rc = -ENODEV; |
| 277 | |
| 278 | /* get the static platform resources */ |
| 279 | res = platform_get_resource(pldev, IORESOURCE_MEM, 0); |
| 280 | if (!res) { |
| 281 | dev_err(&pldev->dev, "IOMEM resource not found\n"); |
| 282 | goto ret_err; |
| 283 | } |
| 284 | |
| 285 | /* reserve the memory region */ |
Linus Walleij | c6ffdde | 2009-06-14 00:20:36 +0200 | [diff] [blame] | 286 | if (!request_mem_region(res->start, resource_size(res), |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 287 | pldev->name)) { |
| 288 | dev_err(&pldev->dev, |
| 289 | "Unable to get memory/io address region 0x%08x\n", |
| 290 | res->start); |
| 291 | rc = -EBUSY; |
| 292 | goto ret_err; |
| 293 | } |
| 294 | |
| 295 | /* remap the memory */ |
| 296 | pmcmsptwi_data.iobase = ioremap_nocache(res->start, |
Linus Walleij | c6ffdde | 2009-06-14 00:20:36 +0200 | [diff] [blame] | 297 | resource_size(res)); |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 298 | if (!pmcmsptwi_data.iobase) { |
| 299 | dev_err(&pldev->dev, |
| 300 | "Unable to ioremap address 0x%08x\n", res->start); |
| 301 | rc = -EIO; |
| 302 | goto ret_unreserve; |
| 303 | } |
| 304 | |
| 305 | /* request the irq */ |
| 306 | pmcmsptwi_data.irq = platform_get_irq(pldev, 0); |
| 307 | if (pmcmsptwi_data.irq) { |
| 308 | rc = request_irq(pmcmsptwi_data.irq, &pmcmsptwi_interrupt, |
| 309 | IRQF_SHARED | IRQF_DISABLED | IRQF_SAMPLE_RANDOM, |
| 310 | pldev->name, &pmcmsptwi_data); |
| 311 | if (rc == 0) { |
| 312 | /* |
| 313 | * Enable 'DONE' interrupt only. |
| 314 | * |
| 315 | * If you enable all interrupts, you will get one on |
| 316 | * error and another when the operation completes. |
| 317 | * This way you only have to handle one interrupt, |
| 318 | * but you can still check all result flags. |
| 319 | */ |
| 320 | pmcmsptwi_writel(MSP_TWI_INT_STS_DONE, |
| 321 | pmcmsptwi_data.iobase + |
| 322 | MSP_TWI_INT_MSK_REG_OFFSET); |
| 323 | } else { |
| 324 | dev_warn(&pldev->dev, |
| 325 | "Could not assign TWI IRQ handler " |
| 326 | "to irq %d (continuing with poll)\n", |
| 327 | pmcmsptwi_data.irq); |
| 328 | pmcmsptwi_data.irq = 0; |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | init_completion(&pmcmsptwi_data.wait); |
| 333 | mutex_init(&pmcmsptwi_data.lock); |
| 334 | |
| 335 | pmcmsptwi_set_clock_config(&pmcmsptwi_defclockcfg, &pmcmsptwi_data); |
| 336 | pmcmsptwi_set_twi_config(&pmcmsptwi_defcfg, &pmcmsptwi_data); |
| 337 | |
| 338 | printk(KERN_INFO DRV_NAME ": Registering MSP71xx I2C adapter\n"); |
| 339 | |
| 340 | pmcmsptwi_adapter.dev.parent = &pldev->dev; |
| 341 | platform_set_drvdata(pldev, &pmcmsptwi_adapter); |
| 342 | i2c_set_adapdata(&pmcmsptwi_adapter, &pmcmsptwi_data); |
| 343 | |
| 344 | rc = i2c_add_adapter(&pmcmsptwi_adapter); |
| 345 | if (rc) { |
| 346 | dev_err(&pldev->dev, "Unable to register I2C adapter\n"); |
| 347 | goto ret_unmap; |
| 348 | } |
| 349 | |
| 350 | return 0; |
| 351 | |
| 352 | ret_unmap: |
| 353 | platform_set_drvdata(pldev, NULL); |
| 354 | if (pmcmsptwi_data.irq) { |
| 355 | pmcmsptwi_writel(0, |
| 356 | pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET); |
| 357 | free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data); |
| 358 | } |
| 359 | |
| 360 | iounmap(pmcmsptwi_data.iobase); |
| 361 | |
| 362 | ret_unreserve: |
Linus Walleij | c6ffdde | 2009-06-14 00:20:36 +0200 | [diff] [blame] | 363 | release_mem_region(res->start, resource_size(res)); |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 364 | |
| 365 | ret_err: |
| 366 | return rc; |
| 367 | } |
| 368 | |
| 369 | /* |
| 370 | * Release the device and return 0 if there is one. |
| 371 | */ |
| 372 | static int __devexit pmcmsptwi_remove(struct platform_device *pldev) |
| 373 | { |
| 374 | struct resource *res; |
| 375 | |
| 376 | i2c_del_adapter(&pmcmsptwi_adapter); |
| 377 | |
| 378 | platform_set_drvdata(pldev, NULL); |
| 379 | if (pmcmsptwi_data.irq) { |
| 380 | pmcmsptwi_writel(0, |
| 381 | pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET); |
| 382 | free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data); |
| 383 | } |
| 384 | |
| 385 | iounmap(pmcmsptwi_data.iobase); |
| 386 | |
| 387 | res = platform_get_resource(pldev, IORESOURCE_MEM, 0); |
Linus Walleij | c6ffdde | 2009-06-14 00:20:36 +0200 | [diff] [blame] | 388 | release_mem_region(res->start, resource_size(res)); |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 389 | |
| 390 | return 0; |
| 391 | } |
| 392 | |
| 393 | /* |
| 394 | * Polls the 'busy' register until the command is complete. |
| 395 | * NOTE: Assumes data->lock is held. |
| 396 | */ |
| 397 | static void pmcmsptwi_poll_complete(struct pmcmsptwi_data *data) |
| 398 | { |
| 399 | int i; |
| 400 | |
| 401 | for (i = 0; i < MSP_MAX_POLL; i++) { |
| 402 | u32 val = pmcmsptwi_readl(data->iobase + |
| 403 | MSP_TWI_BUSY_REG_OFFSET); |
| 404 | if (val == 0) { |
| 405 | u32 reason = pmcmsptwi_readl(data->iobase + |
| 406 | MSP_TWI_INT_STS_REG_OFFSET); |
| 407 | pmcmsptwi_writel(reason, data->iobase + |
| 408 | MSP_TWI_INT_STS_REG_OFFSET); |
| 409 | data->last_result = pmcmsptwi_get_result(reason); |
| 410 | return; |
| 411 | } |
| 412 | udelay(MSP_POLL_DELAY); |
| 413 | } |
| 414 | |
| 415 | dev_dbg(&pmcmsptwi_adapter.dev, "Result: Poll timeout\n"); |
| 416 | data->last_result = MSP_TWI_XFER_TIMEOUT; |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * Do the transfer (low level): |
| 421 | * May use interrupt-driven or polling, depending on if an IRQ is |
| 422 | * presently registered. |
| 423 | * NOTE: Assumes data->lock is held. |
| 424 | */ |
| 425 | static enum pmcmsptwi_xfer_result pmcmsptwi_do_xfer( |
| 426 | u32 reg, struct pmcmsptwi_data *data) |
| 427 | { |
| 428 | dev_dbg(&pmcmsptwi_adapter.dev, "Writing cmd reg 0x%08x\n", reg); |
| 429 | pmcmsptwi_writel(reg, data->iobase + MSP_TWI_CMD_REG_OFFSET); |
| 430 | if (data->irq) { |
| 431 | unsigned long timeleft = wait_for_completion_timeout( |
| 432 | &data->wait, MSP_IRQ_TIMEOUT); |
| 433 | if (timeleft == 0) { |
| 434 | dev_dbg(&pmcmsptwi_adapter.dev, |
| 435 | "Result: IRQ timeout\n"); |
| 436 | complete(&data->wait); |
| 437 | data->last_result = MSP_TWI_XFER_TIMEOUT; |
| 438 | } |
| 439 | } else |
| 440 | pmcmsptwi_poll_complete(data); |
| 441 | |
| 442 | return data->last_result; |
| 443 | } |
| 444 | |
| 445 | /* |
| 446 | * Helper routine, converts 'pmctwi_cmd' struct to register format |
| 447 | */ |
| 448 | static inline u32 pmcmsptwi_cmd_to_reg(const struct pmcmsptwi_cmd *cmd) |
| 449 | { |
| 450 | return ((cmd->type & 0x3) << 8) | |
| 451 | (((cmd->write_len - 1) & 0x7) << 4) | |
| 452 | ((cmd->read_len - 1) & 0x7); |
| 453 | } |
| 454 | |
| 455 | /* |
| 456 | * Do the transfer (high level) |
| 457 | */ |
| 458 | static enum pmcmsptwi_xfer_result pmcmsptwi_xfer_cmd( |
| 459 | struct pmcmsptwi_cmd *cmd, |
| 460 | struct pmcmsptwi_data *data) |
| 461 | { |
| 462 | enum pmcmsptwi_xfer_result retval; |
| 463 | |
| 464 | if ((cmd->type == MSP_TWI_CMD_WRITE && cmd->write_len == 0) || |
| 465 | (cmd->type == MSP_TWI_CMD_READ && cmd->read_len == 0) || |
| 466 | (cmd->type == MSP_TWI_CMD_WRITE_READ && |
| 467 | (cmd->read_len == 0 || cmd->write_len == 0))) { |
| 468 | dev_err(&pmcmsptwi_adapter.dev, |
| 469 | "%s: Cannot transfer less than 1 byte\n", |
Harvey Harrison | 08882d2 | 2008-04-22 22:16:47 +0200 | [diff] [blame] | 470 | __func__); |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 471 | return -EINVAL; |
| 472 | } |
| 473 | |
| 474 | if (cmd->read_len > MSP_MAX_BYTES_PER_RW || |
| 475 | cmd->write_len > MSP_MAX_BYTES_PER_RW) { |
| 476 | dev_err(&pmcmsptwi_adapter.dev, |
| 477 | "%s: Cannot transfer more than %d bytes\n", |
Harvey Harrison | 08882d2 | 2008-04-22 22:16:47 +0200 | [diff] [blame] | 478 | __func__, MSP_MAX_BYTES_PER_RW); |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 479 | return -EINVAL; |
| 480 | } |
| 481 | |
| 482 | mutex_lock(&data->lock); |
| 483 | dev_dbg(&pmcmsptwi_adapter.dev, |
| 484 | "Setting address to 0x%04x\n", cmd->addr); |
| 485 | pmcmsptwi_writel(cmd->addr, data->iobase + MSP_TWI_ADD_REG_OFFSET); |
| 486 | |
| 487 | if (cmd->type == MSP_TWI_CMD_WRITE || |
| 488 | cmd->type == MSP_TWI_CMD_WRITE_READ) { |
Harvey Harrison | d9d38ca | 2008-12-11 12:11:20 +0100 | [diff] [blame] | 489 | u64 tmp = be64_to_cpup((__be64 *)cmd->write_data); |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 490 | tmp >>= (MSP_MAX_BYTES_PER_RW - cmd->write_len) * 8; |
| 491 | dev_dbg(&pmcmsptwi_adapter.dev, "Writing 0x%016llx\n", tmp); |
| 492 | pmcmsptwi_writel(tmp & 0x00000000ffffffffLL, |
| 493 | data->iobase + MSP_TWI_DAT_0_REG_OFFSET); |
| 494 | if (cmd->write_len > 4) |
| 495 | pmcmsptwi_writel(tmp >> 32, |
| 496 | data->iobase + MSP_TWI_DAT_1_REG_OFFSET); |
| 497 | } |
| 498 | |
| 499 | retval = pmcmsptwi_do_xfer(pmcmsptwi_cmd_to_reg(cmd), data); |
| 500 | if (retval != MSP_TWI_XFER_OK) |
| 501 | goto xfer_err; |
| 502 | |
| 503 | if (cmd->type == MSP_TWI_CMD_READ || |
| 504 | cmd->type == MSP_TWI_CMD_WRITE_READ) { |
| 505 | int i; |
| 506 | u64 rmsk = ~(0xffffffffffffffffLL << (cmd->read_len * 8)); |
| 507 | u64 tmp = (u64)pmcmsptwi_readl(data->iobase + |
| 508 | MSP_TWI_DAT_0_REG_OFFSET); |
| 509 | if (cmd->read_len > 4) |
| 510 | tmp |= (u64)pmcmsptwi_readl(data->iobase + |
| 511 | MSP_TWI_DAT_1_REG_OFFSET) << 32; |
| 512 | tmp &= rmsk; |
| 513 | dev_dbg(&pmcmsptwi_adapter.dev, "Read 0x%016llx\n", tmp); |
| 514 | |
| 515 | for (i = 0; i < cmd->read_len; i++) |
| 516 | cmd->read_data[i] = tmp >> i; |
| 517 | } |
| 518 | |
| 519 | xfer_err: |
| 520 | mutex_unlock(&data->lock); |
| 521 | |
| 522 | return retval; |
| 523 | } |
| 524 | |
| 525 | /* -- Algorithm functions -- */ |
| 526 | |
| 527 | /* |
| 528 | * Sends an i2c command out on the adapter |
| 529 | */ |
| 530 | static int pmcmsptwi_master_xfer(struct i2c_adapter *adap, |
| 531 | struct i2c_msg *msg, int num) |
| 532 | { |
| 533 | struct pmcmsptwi_data *data = i2c_get_adapdata(adap); |
| 534 | struct pmcmsptwi_cmd cmd; |
| 535 | struct pmcmsptwi_cfg oldcfg, newcfg; |
| 536 | int ret; |
| 537 | |
| 538 | if (num > 2) { |
| 539 | dev_dbg(&adap->dev, "%d messages unsupported\n", num); |
| 540 | return -EINVAL; |
| 541 | } else if (num == 2) { |
| 542 | /* Check for a dual write-then-read command */ |
| 543 | struct i2c_msg *nextmsg = msg + 1; |
| 544 | if (!(msg->flags & I2C_M_RD) && |
| 545 | (nextmsg->flags & I2C_M_RD) && |
| 546 | msg->addr == nextmsg->addr) { |
| 547 | cmd.type = MSP_TWI_CMD_WRITE_READ; |
| 548 | cmd.write_len = msg->len; |
| 549 | cmd.write_data = msg->buf; |
| 550 | cmd.read_len = nextmsg->len; |
| 551 | cmd.read_data = nextmsg->buf; |
| 552 | } else { |
| 553 | dev_dbg(&adap->dev, |
| 554 | "Non write-read dual messages unsupported\n"); |
| 555 | return -EINVAL; |
| 556 | } |
| 557 | } else if (msg->flags & I2C_M_RD) { |
| 558 | cmd.type = MSP_TWI_CMD_READ; |
| 559 | cmd.read_len = msg->len; |
| 560 | cmd.read_data = msg->buf; |
| 561 | cmd.write_len = 0; |
| 562 | cmd.write_data = NULL; |
| 563 | } else { |
| 564 | cmd.type = MSP_TWI_CMD_WRITE; |
| 565 | cmd.read_len = 0; |
| 566 | cmd.read_data = NULL; |
| 567 | cmd.write_len = msg->len; |
| 568 | cmd.write_data = msg->buf; |
| 569 | } |
| 570 | |
| 571 | if (msg->len == 0) { |
| 572 | dev_err(&adap->dev, "Zero-byte messages unsupported\n"); |
| 573 | return -EINVAL; |
| 574 | } |
| 575 | |
| 576 | cmd.addr = msg->addr; |
| 577 | |
| 578 | if (msg->flags & I2C_M_TEN) { |
| 579 | pmcmsptwi_get_twi_config(&newcfg, data); |
| 580 | memcpy(&oldcfg, &newcfg, sizeof(oldcfg)); |
| 581 | |
| 582 | /* Set the special 10-bit address flag */ |
| 583 | newcfg.add10 = 1; |
| 584 | |
| 585 | pmcmsptwi_set_twi_config(&newcfg, data); |
| 586 | } |
| 587 | |
| 588 | /* Execute the command */ |
| 589 | ret = pmcmsptwi_xfer_cmd(&cmd, data); |
| 590 | |
| 591 | if (msg->flags & I2C_M_TEN) |
| 592 | pmcmsptwi_set_twi_config(&oldcfg, data); |
| 593 | |
Joe Perches | 898eb71 | 2007-10-18 03:06:30 -0700 | [diff] [blame] | 594 | dev_dbg(&adap->dev, "I2C %s of %d bytes %s\n", |
| 595 | (msg->flags & I2C_M_RD) ? "read" : "write", msg->len, |
| 596 | (ret == MSP_TWI_XFER_OK) ? "succeeded" : "failed"); |
| 597 | |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 598 | if (ret != MSP_TWI_XFER_OK) { |
| 599 | /* |
| 600 | * TODO: We could potentially loop and retry in the case |
| 601 | * of MSP_TWI_XFER_TIMEOUT. |
| 602 | */ |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 603 | return -1; |
| 604 | } |
| 605 | |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 606 | return 0; |
| 607 | } |
| 608 | |
| 609 | static u32 pmcmsptwi_i2c_func(struct i2c_adapter *adapter) |
| 610 | { |
| 611 | return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | |
| 612 | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | |
| 613 | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL; |
| 614 | } |
| 615 | |
| 616 | /* -- Initialization -- */ |
| 617 | |
| 618 | static struct i2c_algorithm pmcmsptwi_algo = { |
| 619 | .master_xfer = pmcmsptwi_master_xfer, |
| 620 | .functionality = pmcmsptwi_i2c_func, |
| 621 | }; |
| 622 | |
| 623 | static struct i2c_adapter pmcmsptwi_adapter = { |
| 624 | .owner = THIS_MODULE, |
Jean Delvare | 3401b2f | 2008-07-14 22:38:29 +0200 | [diff] [blame] | 625 | .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 626 | .algo = &pmcmsptwi_algo, |
| 627 | .name = DRV_NAME, |
| 628 | }; |
| 629 | |
Kay Sievers | add8eda | 2008-04-22 22:16:49 +0200 | [diff] [blame] | 630 | /* work with hotplug and coldplug */ |
| 631 | MODULE_ALIAS("platform:" DRV_NAME); |
| 632 | |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 633 | static struct platform_driver pmcmsptwi_driver = { |
| 634 | .probe = pmcmsptwi_probe, |
| 635 | .remove = __devexit_p(pmcmsptwi_remove), |
Yoann Padioleau | 5ee403f | 2007-07-17 04:03:01 -0700 | [diff] [blame] | 636 | .driver = { |
Marc St-Jean | 1b144df | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 637 | .name = DRV_NAME, |
| 638 | .owner = THIS_MODULE, |
| 639 | }, |
| 640 | }; |
| 641 | |
| 642 | static int __init pmcmsptwi_init(void) |
| 643 | { |
| 644 | return platform_driver_register(&pmcmsptwi_driver); |
| 645 | } |
| 646 | |
| 647 | static void __exit pmcmsptwi_exit(void) |
| 648 | { |
| 649 | platform_driver_unregister(&pmcmsptwi_driver); |
| 650 | } |
| 651 | |
| 652 | MODULE_DESCRIPTION("PMC MSP TWI/SMBus/I2C driver"); |
| 653 | MODULE_LICENSE("GPL"); |
| 654 | |
| 655 | module_init(pmcmsptwi_init); |
| 656 | module_exit(pmcmsptwi_exit); |