| 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); |