+++ /dev/null
-/*
- * 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 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 %pap\n",
- &res->start);
- rc = -EBUSY;
- goto ret_err;
- }
-
- /* remap the memory */
- pmcmsptwi_data.iobase = ioremap(res->start,
- resource_size(res));
- if (!pmcmsptwi_data.iobase) {
- dev_err(&pldev->dev,
- "Unable to ioremap address %pap\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)
- 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;
-
- 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) {
- struct i2c_msg *nextmsg = msg + 1;
-
- 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 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;
- }
-
- 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 -EIO;
- }
-
- return num;
-}
-
-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;
-}
-
-static const struct i2c_adapter_quirks pmcmsptwi_i2c_quirks = {
- .flags = I2C_AQ_COMB_WRITE_THEN_READ | I2C_AQ_NO_ZERO_LEN,
- .max_write_len = MSP_MAX_BYTES_PER_RW,
- .max_read_len = MSP_MAX_BYTES_PER_RW,
- .max_comb_1st_msg_len = MSP_MAX_BYTES_PER_RW,
- .max_comb_2nd_msg_len = MSP_MAX_BYTES_PER_RW,
-};
-
-/* -- Initialization -- */
-
-static const 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,
- .quirks = &pmcmsptwi_i2c_quirks,
- .name = DRV_NAME,
-};
-
-static struct platform_driver pmcmsptwi_driver = {
- .probe = pmcmsptwi_probe,
- .remove = pmcmsptwi_remove,
- .driver = {
- .name = DRV_NAME,
- },
-};
-
-module_platform_driver(pmcmsptwi_driver);
-
-MODULE_DESCRIPTION("PMC MSP TWI/SMBus/I2C driver");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:" DRV_NAME);
projects / platform / kernel / linux-starfive.git / commitdiff