i2c-pmcmsp.c

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			pmcmsptwi_data.irq = 0;
		}
	}

	init_completion(&pmcmsptwi_data.wait);
	mutex_init(&pmcmsptwi_data.lock);

	pmcmsptwi_set_clock_config(&pmcmsptwi_defclockcfg, &pmcmsptwi_data);
	pmcmsptwi_set_twi_config(&pmcmsptwi_defcfg, &pmcmsptwi_data);

	printk(KERN_INFO DRV_NAME ": Registering MSP71xx I2C adapter\n");

	pmcmsptwi_adapter.dev.parent = &pldev->dev;
	platform_set_drvdata(pldev, &pmcmsptwi_adapter);
	i2c_set_adapdata(&pmcmsptwi_adapter, &pmcmsptwi_data);

	rc = i2c_add_adapter(&pmcmsptwi_adapter);
	if (rc) {
		dev_err(&pldev->dev, "Unable to register I2C adapter\n");
		goto ret_unmap;
	}

	return 0;

ret_unmap:
	platform_set_drvdata(pldev, NULL);
	if (pmcmsptwi_data.irq) {
		pmcmsptwi_writel(0,
			pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET);
		free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data);
	}

	iounmap(pmcmsptwi_data.iobase);

ret_unreserve:
	release_mem_region(res->start, res->end - res->start + 1);

ret_err:
	return rc;
}

/*
 * Release the device and return 0 if there is one.
 */
static int __devexit pmcmsptwi_remove(struct platform_device *pldev)
{
	struct resource *res;

	i2c_del_adapter(&pmcmsptwi_adapter);

	platform_set_drvdata(pldev, NULL);
	if (pmcmsptwi_data.irq) {
		pmcmsptwi_writel(0,
			pmcmsptwi_data.iobase + MSP_TWI_INT_MSK_REG_OFFSET);
		free_irq(pmcmsptwi_data.irq, &pmcmsptwi_data);
	}

	iounmap(pmcmsptwi_data.iobase);

	res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
	release_mem_region(res->start, res->end - res->start + 1);

	return 0;
}

/*
 * Polls the 'busy' register until the command is complete.
 * NOTE: Assumes data->lock is held.
 */
static void pmcmsptwi_poll_complete(struct pmcmsptwi_data *data)
{
	int i;

	for (i = 0; i < MSP_MAX_POLL; i++) {
		u32 val = pmcmsptwi_readl(data->iobase +
						MSP_TWI_BUSY_REG_OFFSET);
		if (val == 0) {
			u32 reason = pmcmsptwi_readl(data->iobase +
						MSP_TWI_INT_STS_REG_OFFSET);
			pmcmsptwi_writel(reason, data->iobase +
						MSP_TWI_INT_STS_REG_OFFSET);
			data->last_result = pmcmsptwi_get_result(reason);
			return;
		}
		udelay(MSP_POLL_DELAY);
	}

	dev_dbg(&pmcmsptwi_adapter.dev, "Result: Poll timeout\n");
	data->last_result = MSP_TWI_XFER_TIMEOUT;
}

/*
 * Do the transfer (low level):
 *   May use interrupt-driven or polling, depending on if an IRQ is
 *   presently registered.
 * NOTE: Assumes data->lock is held.
 */
static enum pmcmsptwi_xfer_result pmcmsptwi_do_xfer(
			u32 reg, struct pmcmsptwi_data *data)
{
	dev_dbg(&pmcmsptwi_adapter.dev, "Writing cmd reg 0x%08x\n", reg);
	pmcmsptwi_writel(reg, data->iobase + MSP_TWI_CMD_REG_OFFSET);
	if (data->irq) {
		unsigned long timeleft = wait_for_completion_timeout(
						&data->wait, MSP_IRQ_TIMEOUT);
		if (timeleft == 0) {
			dev_dbg(&pmcmsptwi_adapter.dev,
				"Result: IRQ timeout\n");
			complete(&data->wait);
			data->last_result = MSP_TWI_XFER_TIMEOUT;
		}
	} else
		pmcmsptwi_poll_complete(data);

	return data->last_result;
}

/*
 * Helper routine, converts 'pmctwi_cmd' struct to register format
 */
static inline u32 pmcmsptwi_cmd_to_reg(const struct pmcmsptwi_cmd *cmd)
{
	return ((cmd->type & 0x3) << 8) |
		(((cmd->write_len - 1) & 0x7) << 4) |
		((cmd->read_len - 1) & 0x7);
}

/*
 * Do the transfer (high level)
 */
static enum pmcmsptwi_xfer_result pmcmsptwi_xfer_cmd(
			struct pmcmsptwi_cmd *cmd,
			struct pmcmsptwi_data *data)
{
	enum pmcmsptwi_xfer_result retval;

	if ((cmd->type == MSP_TWI_CMD_WRITE && cmd->write_len == 0) ||
	    (cmd->type == MSP_TWI_CMD_READ && cmd->read_len == 0) ||
	    (cmd->type == MSP_TWI_CMD_WRITE_READ &&
	    (cmd->read_len == 0 || cmd->write_len == 0))) {
		dev_err(&pmcmsptwi_adapter.dev,
			"%s: Cannot transfer less than 1 byte\n",
			__FUNCTION__);
		return -EINVAL;
	}

	if (cmd->read_len > MSP_MAX_BYTES_PER_RW ||
	    cmd->write_len > MSP_MAX_BYTES_PER_RW) {
		dev_err(&pmcmsptwi_adapter.dev,
			"%s: Cannot transfer more than %d bytes\n",
			__FUNCTION__, MSP_MAX_BYTES_PER_RW);
		return -EINVAL;
	}

	mutex_lock(&data->lock);
	dev_dbg(&pmcmsptwi_adapter.dev,
		"Setting address to 0x%04x\n", cmd->addr);
	pmcmsptwi_writel(cmd->addr, data->iobase + MSP_TWI_ADD_REG_OFFSET);

	if (cmd->type == MSP_TWI_CMD_WRITE ||
	    cmd->type == MSP_TWI_CMD_WRITE_READ) {
		__be64 tmp = cpu_to_be64p((u64 *)cmd->write_data);
		tmp >>= (MSP_MAX_BYTES_PER_RW - cmd->write_len) * 8;
		dev_dbg(&pmcmsptwi_adapter.dev, "Writing 0x%016llx\n", tmp);
		pmcmsptwi_writel(tmp & 0x00000000ffffffffLL,
				data->iobase + MSP_TWI_DAT_0_REG_OFFSET);
		if (cmd->write_len > 4)
			pmcmsptwi_writel(tmp >> 32,
				data->iobase + MSP_TWI_DAT_1_REG_OFFSET);
	}

	retval = pmcmsptwi_do_xfer(pmcmsptwi_cmd_to_reg(cmd), data);
	if (retval != MSP_TWI_XFER_OK)
		goto xfer_err;

	if (cmd->type == MSP_TWI_CMD_READ ||
	    cmd->type == MSP_TWI_CMD_WRITE_READ) {
		int i;
		u64 rmsk = ~(0xffffffffffffffffLL << (cmd->read_len * 8));
		u64 tmp = (u64)pmcmsptwi_readl(data->iobase +
					MSP_TWI_DAT_0_REG_OFFSET);
		if (cmd->read_len > 4)
			tmp |= (u64)pmcmsptwi_readl(data->iobase +
					MSP_TWI_DAT_1_REG_OFFSET) << 32;
		tmp &= rmsk;
		dev_dbg(&pmcmsptwi_adapter.dev, "Read 0x%016llx\n", tmp);

		for (i = 0; i < cmd->read_len; i++)
			cmd->read_data[i] = tmp >> i;
	}

xfer_err:
	mutex_unlock(&data->lock);

	return retval;
}

/* -- Algorithm functions -- */

/*
 * Sends an i2c command out on the adapter
 */
static int pmcmsptwi_master_xfer(struct i2c_adapter *adap,
				struct i2c_msg *msg, int num)
{
	struct pmcmsptwi_data *data = i2c_get_adapdata(adap);
	struct pmcmsptwi_cmd cmd;
	struct pmcmsptwi_cfg oldcfg, newcfg;
	int ret;

	if (num > 2) {
		dev_dbg(&adap->dev, "%d messages unsupported\n", num);
		return -EINVAL;
	} else if (num == 2) {
		/* Check for a dual write-then-read command */
		struct i2c_msg *nextmsg = msg + 1;
		if (!(msg->flags & I2C_M_RD) &&
		    (nextmsg->flags & I2C_M_RD) &&
		    msg->addr == nextmsg->addr) {
			cmd.type = MSP_TWI_CMD_WRITE_READ;
			cmd.write_len = msg->len;
			cmd.write_data = msg->buf;
			cmd.read_len = nextmsg->len;
			cmd.read_data = nextmsg->buf;
		} else {
			dev_dbg(&adap->dev,
				"Non write-read dual messages unsupported\n");
			return -EINVAL;
		}
	} else if (msg->flags & I2C_M_RD) {
		cmd.type = MSP_TWI_CMD_READ;
		cmd.read_len = msg->len;
		cmd.read_data = msg->buf;
		cmd.write_len = 0;
		cmd.write_data = NULL;
	} else {
		cmd.type = MSP_TWI_CMD_WRITE;
		cmd.read_len = 0;
		cmd.read_data = NULL;
		cmd.write_len = msg->len;
		cmd.write_data = msg->buf;
	}

	if (msg->len == 0) {
		dev_err(&adap->dev, "Zero-byte messages unsupported\n");
		return -EINVAL;
	}

	cmd.addr = msg->addr;

	if (msg->flags & I2C_M_TEN) {
		pmcmsptwi_get_twi_config(&newcfg, data);
		memcpy(&oldcfg, &newcfg, sizeof(oldcfg));

		/* Set the special 10-bit address flag */
		newcfg.add10 = 1;

		pmcmsptwi_set_twi_config(&newcfg, data);
	}

	/* Execute the command */
	ret = pmcmsptwi_xfer_cmd(&cmd, data);

	if (msg->flags & I2C_M_TEN)
		pmcmsptwi_set_twi_config(&oldcfg, data);

	dev_dbg(&adap->dev, "I2C %s of %d bytes %s\n",
		(msg->flags & I2C_M_RD) ? "read" : "write", msg->len,
		(ret == MSP_TWI_XFER_OK) ? "succeeded" : "failed");

	if (ret != MSP_TWI_XFER_OK) {
		/*
		 * TODO: We could potentially loop and retry in the case
		 * of MSP_TWI_XFER_TIMEOUT.
		 */
		return -1;
	}

	return 0;
}

static u32 pmcmsptwi_i2c_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
		I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL;
}

/* -- Initialization -- */

static struct i2c_algorithm pmcmsptwi_algo = {
	.master_xfer	= pmcmsptwi_master_xfer,
	.functionality	= pmcmsptwi_i2c_func,
};

static struct i2c_adapter pmcmsptwi_adapter = {
	.owner		= THIS_MODULE,
	.class		= I2C_CLASS_HWMON,
	.algo		= &pmcmsptwi_algo,
	.name		= DRV_NAME,
};

static struct platform_driver pmcmsptwi_driver = {
	.probe  = pmcmsptwi_probe,
	.remove	= __devexit_p(pmcmsptwi_remove),
	.driver = {
		.name	= DRV_NAME,
		.owner	= THIS_MODULE,
	},
};

static int __init pmcmsptwi_init(void)
{
	return platform_driver_register(&pmcmsptwi_driver);
}

static void __exit pmcmsptwi_exit(void)
{
	platform_driver_unregister(&pmcmsptwi_driver);
}

MODULE_DESCRIPTION("PMC MSP TWI/SMBus/I2C driver");
MODULE_LICENSE("GPL");

module_init(pmcmsptwi_init);
module_exit(pmcmsptwi_exit);