|  | /* | 
|  | * Specific bus support for PMC-TWI compliant implementation on MSP71xx. | 
|  | * | 
|  | * Copyright 2005-2007 PMC-Sierra, Inc. | 
|  | * | 
|  | *  This program is free software; you can redistribute  it and/or modify it | 
|  | *  under  the terms of  the GNU General  Public License as published by the | 
|  | *  Free Software Foundation;  either version 2 of the  License, or (at your | 
|  | *  option) any later version. | 
|  | * | 
|  | *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED | 
|  | *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF | 
|  | *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN | 
|  | *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT, | 
|  | *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | 
|  | *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF | 
|  | *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON | 
|  | *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT | 
|  | *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 
|  | *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
|  | */ | 
|  |  | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/completion.h> | 
|  | #include <linux/mutex.h> | 
|  | #include <linux/delay.h> | 
|  | #include <linux/io.h> | 
|  |  | 
|  | #define DRV_NAME	"pmcmsptwi" | 
|  |  | 
|  | #define MSP_TWI_SF_CLK_REG_OFFSET	0x00 | 
|  | #define MSP_TWI_HS_CLK_REG_OFFSET	0x04 | 
|  | #define MSP_TWI_CFG_REG_OFFSET		0x08 | 
|  | #define MSP_TWI_CMD_REG_OFFSET		0x0c | 
|  | #define MSP_TWI_ADD_REG_OFFSET		0x10 | 
|  | #define MSP_TWI_DAT_0_REG_OFFSET	0x14 | 
|  | #define MSP_TWI_DAT_1_REG_OFFSET	0x18 | 
|  | #define MSP_TWI_INT_STS_REG_OFFSET	0x1c | 
|  | #define MSP_TWI_INT_MSK_REG_OFFSET	0x20 | 
|  | #define MSP_TWI_BUSY_REG_OFFSET		0x24 | 
|  |  | 
|  | #define MSP_TWI_INT_STS_DONE			(1 << 0) | 
|  | #define MSP_TWI_INT_STS_LOST_ARBITRATION	(1 << 1) | 
|  | #define MSP_TWI_INT_STS_NO_RESPONSE		(1 << 2) | 
|  | #define MSP_TWI_INT_STS_DATA_COLLISION		(1 << 3) | 
|  | #define MSP_TWI_INT_STS_BUSY			(1 << 4) | 
|  | #define MSP_TWI_INT_STS_ALL			0x1f | 
|  |  | 
|  | #define MSP_MAX_BYTES_PER_RW		8 | 
|  | #define MSP_MAX_POLL			5 | 
|  | #define MSP_POLL_DELAY			10 | 
|  | #define MSP_IRQ_TIMEOUT			(MSP_MAX_POLL * MSP_POLL_DELAY) | 
|  |  | 
|  | /* IO Operation macros */ | 
|  | #define pmcmsptwi_readl		__raw_readl | 
|  | #define pmcmsptwi_writel	__raw_writel | 
|  |  | 
|  | /* TWI command type */ | 
|  | enum pmcmsptwi_cmd_type { | 
|  | MSP_TWI_CMD_WRITE	= 0,	/* Write only */ | 
|  | MSP_TWI_CMD_READ	= 1,	/* Read only */ | 
|  | MSP_TWI_CMD_WRITE_READ	= 2,	/* Write then Read */ | 
|  | }; | 
|  |  | 
|  | /* The possible results of the xferCmd */ | 
|  | enum pmcmsptwi_xfer_result { | 
|  | MSP_TWI_XFER_OK	= 0, | 
|  | MSP_TWI_XFER_TIMEOUT, | 
|  | MSP_TWI_XFER_BUSY, | 
|  | MSP_TWI_XFER_DATA_COLLISION, | 
|  | MSP_TWI_XFER_NO_RESPONSE, | 
|  | MSP_TWI_XFER_LOST_ARBITRATION, | 
|  | }; | 
|  |  | 
|  | /* Corresponds to a PMCTWI clock configuration register */ | 
|  | struct pmcmsptwi_clock { | 
|  | u8 filter;	/* Bits 15:12,	default = 0x03 */ | 
|  | u16 clock;	/* Bits 9:0,	default = 0x001f */ | 
|  | }; | 
|  |  | 
|  | struct pmcmsptwi_clockcfg { | 
|  | struct pmcmsptwi_clock standard;  /* The standard/fast clock config */ | 
|  | struct pmcmsptwi_clock highspeed; /* The highspeed clock config */ | 
|  | }; | 
|  |  | 
|  | /* Corresponds to the main TWI configuration register */ | 
|  | struct pmcmsptwi_cfg { | 
|  | u8 arbf;	/* Bits 15:12,	default=0x03 */ | 
|  | u8 nak;		/* Bits 11:8,	default=0x03 */ | 
|  | u8 add10;	/* Bit 7,	default=0x00 */ | 
|  | u8 mst_code;	/* Bits 6:4,	default=0x00 */ | 
|  | u8 arb;		/* Bit 1,	default=0x01 */ | 
|  | u8 highspeed;	/* Bit 0,	default=0x00 */ | 
|  | }; | 
|  |  | 
|  | /* A single pmctwi command to issue */ | 
|  | struct pmcmsptwi_cmd { | 
|  | u16 addr;	/* The slave address (7 or 10 bits) */ | 
|  | enum pmcmsptwi_cmd_type type;	/* The command type */ | 
|  | u8 write_len;	/* Number of bytes in the write buffer */ | 
|  | u8 read_len;	/* Number of bytes in the read buffer */ | 
|  | u8 *write_data;	/* Buffer of characters to send */ | 
|  | u8 *read_data;	/* Buffer to fill with incoming data */ | 
|  | }; | 
|  |  | 
|  | /* The private data */ | 
|  | struct pmcmsptwi_data { | 
|  | void __iomem *iobase;			/* iomapped base for IO */ | 
|  | int irq;				/* IRQ to use (0 disables) */ | 
|  | struct completion wait;			/* Completion for xfer */ | 
|  | struct mutex lock;			/* Used for threadsafeness */ | 
|  | enum pmcmsptwi_xfer_result last_result;	/* result of last xfer */ | 
|  | }; | 
|  |  | 
|  | /* The default settings */ | 
|  | static const struct pmcmsptwi_clockcfg pmcmsptwi_defclockcfg = { | 
|  | .standard = { | 
|  | .filter	= 0x3, | 
|  | .clock	= 0x1f, | 
|  | }, | 
|  | .highspeed = { | 
|  | .filter	= 0x3, | 
|  | .clock	= 0x1f, | 
|  | }, | 
|  | }; | 
|  |  | 
|  | static const struct pmcmsptwi_cfg pmcmsptwi_defcfg = { | 
|  | .arbf		= 0x03, | 
|  | .nak		= 0x03, | 
|  | .add10		= 0x00, | 
|  | .mst_code	= 0x00, | 
|  | .arb		= 0x01, | 
|  | .highspeed	= 0x00, | 
|  | }; | 
|  |  | 
|  | static struct pmcmsptwi_data pmcmsptwi_data; | 
|  |  | 
|  | static struct i2c_adapter pmcmsptwi_adapter; | 
|  |  | 
|  | /* inline helper functions */ | 
|  | static inline u32 pmcmsptwi_clock_to_reg( | 
|  | const struct pmcmsptwi_clock *clock) | 
|  | { | 
|  | return ((clock->filter & 0xf) << 12) | (clock->clock & 0x03ff); | 
|  | } | 
|  |  | 
|  | static inline void pmcmsptwi_reg_to_clock( | 
|  | u32 reg, struct pmcmsptwi_clock *clock) | 
|  | { | 
|  | clock->filter = (reg >> 12) & 0xf; | 
|  | clock->clock = reg & 0x03ff; | 
|  | } | 
|  |  | 
|  | static inline u32 pmcmsptwi_cfg_to_reg(const struct pmcmsptwi_cfg *cfg) | 
|  | { | 
|  | return ((cfg->arbf & 0xf) << 12) | | 
|  | ((cfg->nak & 0xf) << 8) | | 
|  | ((cfg->add10 & 0x1) << 7) | | 
|  | ((cfg->mst_code & 0x7) << 4) | | 
|  | ((cfg->arb & 0x1) << 1) | | 
|  | (cfg->highspeed & 0x1); | 
|  | } | 
|  |  | 
|  | static inline void pmcmsptwi_reg_to_cfg(u32 reg, struct pmcmsptwi_cfg *cfg) | 
|  | { | 
|  | cfg->arbf = (reg >> 12) & 0xf; | 
|  | cfg->nak = (reg >> 8) & 0xf; | 
|  | cfg->add10 = (reg >> 7) & 0x1; | 
|  | cfg->mst_code = (reg >> 4) & 0x7; | 
|  | cfg->arb = (reg >> 1) & 0x1; | 
|  | cfg->highspeed = reg & 0x1; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Sets the current clock configuration | 
|  | */ | 
|  | static void pmcmsptwi_set_clock_config(const struct pmcmsptwi_clockcfg *cfg, | 
|  | struct pmcmsptwi_data *data) | 
|  | { | 
|  | mutex_lock(&data->lock); | 
|  | pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->standard), | 
|  | data->iobase + MSP_TWI_SF_CLK_REG_OFFSET); | 
|  | pmcmsptwi_writel(pmcmsptwi_clock_to_reg(&cfg->highspeed), | 
|  | data->iobase + MSP_TWI_HS_CLK_REG_OFFSET); | 
|  | mutex_unlock(&data->lock); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Gets the current TWI bus configuration | 
|  | */ | 
|  | static void pmcmsptwi_get_twi_config(struct pmcmsptwi_cfg *cfg, | 
|  | struct pmcmsptwi_data *data) | 
|  | { | 
|  | mutex_lock(&data->lock); | 
|  | pmcmsptwi_reg_to_cfg(pmcmsptwi_readl( | 
|  | data->iobase + MSP_TWI_CFG_REG_OFFSET), cfg); | 
|  | mutex_unlock(&data->lock); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Sets the current TWI bus configuration | 
|  | */ | 
|  | static void pmcmsptwi_set_twi_config(const struct pmcmsptwi_cfg *cfg, | 
|  | struct pmcmsptwi_data *data) | 
|  | { | 
|  | mutex_lock(&data->lock); | 
|  | pmcmsptwi_writel(pmcmsptwi_cfg_to_reg(cfg), | 
|  | data->iobase + MSP_TWI_CFG_REG_OFFSET); | 
|  | mutex_unlock(&data->lock); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Parses the 'int_sts' register and returns a well-defined error code | 
|  | */ | 
|  | static enum pmcmsptwi_xfer_result pmcmsptwi_get_result(u32 reg) | 
|  | { | 
|  | if (reg & MSP_TWI_INT_STS_LOST_ARBITRATION) { | 
|  | dev_dbg(&pmcmsptwi_adapter.dev, | 
|  | "Result: Lost arbitration\n"); | 
|  | return MSP_TWI_XFER_LOST_ARBITRATION; | 
|  | } else if (reg & MSP_TWI_INT_STS_NO_RESPONSE) { | 
|  | dev_dbg(&pmcmsptwi_adapter.dev, | 
|  | "Result: No response\n"); | 
|  | return MSP_TWI_XFER_NO_RESPONSE; | 
|  | } else if (reg & MSP_TWI_INT_STS_DATA_COLLISION) { | 
|  | dev_dbg(&pmcmsptwi_adapter.dev, | 
|  | "Result: Data collision\n"); | 
|  | return MSP_TWI_XFER_DATA_COLLISION; | 
|  | } else if (reg & MSP_TWI_INT_STS_BUSY) { | 
|  | dev_dbg(&pmcmsptwi_adapter.dev, | 
|  | "Result: Bus busy\n"); | 
|  | return MSP_TWI_XFER_BUSY; | 
|  | } | 
|  |  | 
|  | dev_dbg(&pmcmsptwi_adapter.dev, "Result: Operation succeeded\n"); | 
|  | return MSP_TWI_XFER_OK; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * In interrupt mode, handle the interrupt. | 
|  | * NOTE: Assumes data->lock is held. | 
|  | */ | 
|  | static irqreturn_t pmcmsptwi_interrupt(int irq, void *ptr) | 
|  | { | 
|  | struct pmcmsptwi_data *data = ptr; | 
|  |  | 
|  | u32 reason = pmcmsptwi_readl(data->iobase + | 
|  | MSP_TWI_INT_STS_REG_OFFSET); | 
|  | pmcmsptwi_writel(reason, data->iobase + MSP_TWI_INT_STS_REG_OFFSET); | 
|  |  | 
|  | dev_dbg(&pmcmsptwi_adapter.dev, "Got interrupt 0x%08x\n", reason); | 
|  | if (!(reason & MSP_TWI_INT_STS_DONE)) | 
|  | return IRQ_NONE; | 
|  |  | 
|  | data->last_result = pmcmsptwi_get_result(reason); | 
|  | complete(&data->wait); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Probe for and register the device and return 0 if there is one. | 
|  | */ | 
|  | static int pmcmsptwi_probe(struct platform_device *pldev) | 
|  | { | 
|  | struct resource *res; | 
|  | int rc = -ENODEV; | 
|  |  | 
|  | /* get the static platform resources */ | 
|  | res = platform_get_resource(pldev, IORESOURCE_MEM, 0); | 
|  | if (!res) { | 
|  | dev_err(&pldev->dev, "IOMEM resource not found\n"); | 
|  | goto ret_err; | 
|  | } | 
|  |  | 
|  | /* reserve the memory region */ | 
|  | if (!request_mem_region(res->start, resource_size(res), | 
|  | pldev->name)) { | 
|  | dev_err(&pldev->dev, | 
|  | "Unable to get memory/io address region 0x%08x\n", | 
|  | res->start); | 
|  | rc = -EBUSY; | 
|  | goto ret_err; | 
|  | } | 
|  |  | 
|  | /* remap the memory */ | 
|  | pmcmsptwi_data.iobase = ioremap_nocache(res->start, | 
|  | resource_size(res)); | 
|  | if (!pmcmsptwi_data.iobase) { | 
|  | dev_err(&pldev->dev, | 
|  | "Unable to ioremap address 0x%08x\n", res->start); | 
|  | rc = -EIO; | 
|  | goto ret_unreserve; | 
|  | } | 
|  |  | 
|  | /* request the irq */ | 
|  | pmcmsptwi_data.irq = platform_get_irq(pldev, 0); | 
|  | if (pmcmsptwi_data.irq) { | 
|  | rc = request_irq(pmcmsptwi_data.irq, &pmcmsptwi_interrupt, | 
|  | IRQF_SHARED, pldev->name, &pmcmsptwi_data); | 
|  | if (rc == 0) { | 
|  | /* | 
|  | * Enable 'DONE' interrupt only. | 
|  | * | 
|  | * If you enable all interrupts, you will get one on | 
|  | * error and another when the operation completes. | 
|  | * This way you only have to handle one interrupt, | 
|  | * but you can still check all result flags. | 
|  | */ | 
|  | pmcmsptwi_writel(MSP_TWI_INT_STS_DONE, | 
|  | pmcmsptwi_data.iobase + | 
|  | MSP_TWI_INT_MSK_REG_OFFSET); | 
|  | } else { | 
|  | dev_warn(&pldev->dev, | 
|  | "Could not assign TWI IRQ handler " | 
|  | "to irq %d (continuing with poll)\n", | 
|  | pmcmsptwi_data.irq); | 
|  | 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: | 
|  | 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, resource_size(res)); | 
|  |  | 
|  | ret_err: | 
|  | return rc; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Release the device and return 0 if there is one. | 
|  | */ | 
|  | static int pmcmsptwi_remove(struct platform_device *pldev) | 
|  | { | 
|  | struct resource *res; | 
|  |  | 
|  | i2c_del_adapter(&pmcmsptwi_adapter); | 
|  |  | 
|  | 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, resource_size(res)); | 
|  |  | 
|  | 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", | 
|  | __func__); | 
|  | 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", | 
|  | __func__, 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) { | 
|  | u64 tmp = be64_to_cpup((__be64 *)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 | I2C_CLASS_SPD, | 
|  | .algo		= &pmcmsptwi_algo, | 
|  | .name		= DRV_NAME, | 
|  | }; | 
|  |  | 
|  | static struct platform_driver pmcmsptwi_driver = { | 
|  | .probe  = pmcmsptwi_probe, | 
|  | .remove	= pmcmsptwi_remove, | 
|  | .driver = { | 
|  | .name	= DRV_NAME, | 
|  | .owner	= THIS_MODULE, | 
|  | }, | 
|  | }; | 
|  |  | 
|  | module_platform_driver(pmcmsptwi_driver); | 
|  |  | 
|  | MODULE_DESCRIPTION("PMC MSP TWI/SMBus/I2C driver"); | 
|  | MODULE_LICENSE("GPL"); | 
|  | MODULE_ALIAS("platform:" DRV_NAME); |