| 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 */ | 
|  | 286 | if (!request_mem_region(res->start, res->end - res->start + 1, | 
|  | 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, | 
|  | 297 | res->end - res->start + 1); | 
|  | 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: | 
|  | 363 | release_mem_region(res->start, res->end - res->start + 1); | 
|  | 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); | 
|  | 388 | release_mem_region(res->start, res->end - res->start + 1); | 
|  | 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) { | 
|  | 489 | __be64 tmp = cpu_to_be64p((u64 *)cmd->write_data); | 
|  | 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); |