diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-mv64xxx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mv64xxx.c | 598 |
1 files changed, 598 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c new file mode 100644 index 00000000000..5b852782d2f --- /dev/null +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -0,0 +1,598 @@ +/* + * drivers/i2c/busses/i2c-mv64xxx.c + * + * Driver for the i2c controller on the Marvell line of host bridges for MIPS + * and PPC (e.g, gt642[46]0, mv643[46]0, mv644[46]0). + * + * Author: Mark A. Greer <mgreer@mvista.com> + * + * 2005 (c) MontaVista, Software, Inc. This file is licensed under + * the terms of the GNU General Public License version 2. This program + * is licensed "as is" without any warranty of any kind, whether express + * or implied. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/mv643xx.h> +#include <asm/io.h> + +/* Register defines */ +#define MV64XXX_I2C_REG_SLAVE_ADDR 0x00 +#define MV64XXX_I2C_REG_DATA 0x04 +#define MV64XXX_I2C_REG_CONTROL 0x08 +#define MV64XXX_I2C_REG_STATUS 0x0c +#define MV64XXX_I2C_REG_BAUD 0x0c +#define MV64XXX_I2C_REG_EXT_SLAVE_ADDR 0x10 +#define MV64XXX_I2C_REG_SOFT_RESET 0x1c + +#define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004 +#define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008 +#define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010 +#define MV64XXX_I2C_REG_CONTROL_START 0x00000020 +#define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040 +#define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080 + +/* Ctlr status values */ +#define MV64XXX_I2C_STATUS_BUS_ERR 0x00 +#define MV64XXX_I2C_STATUS_MAST_START 0x08 +#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 +#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28 +#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30 +#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 +#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50 +#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 +#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8 + +/* Driver states */ +enum { + MV64XXX_I2C_STATE_INVALID, + MV64XXX_I2C_STATE_IDLE, + MV64XXX_I2C_STATE_WAITING_FOR_START_COND, + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA, + MV64XXX_I2C_STATE_ABORTING, +}; + +/* Driver actions */ +enum { + MV64XXX_I2C_ACTION_INVALID, + MV64XXX_I2C_ACTION_CONTINUE, + MV64XXX_I2C_ACTION_SEND_START, + MV64XXX_I2C_ACTION_SEND_ADDR_1, + MV64XXX_I2C_ACTION_SEND_ADDR_2, + MV64XXX_I2C_ACTION_SEND_DATA, + MV64XXX_I2C_ACTION_RCV_DATA, + MV64XXX_I2C_ACTION_RCV_DATA_STOP, + MV64XXX_I2C_ACTION_SEND_STOP, +}; + +struct mv64xxx_i2c_data { + int irq; + u32 state; + u32 action; + u32 cntl_bits; + void __iomem *reg_base; + u32 reg_base_p; + u32 addr1; + u32 addr2; + u32 bytes_left; + u32 byte_posn; + u32 block; + int rc; + u32 freq_m; + u32 freq_n; + wait_queue_head_t waitq; + spinlock_t lock; + struct i2c_msg *msg; + struct i2c_adapter adapter; +}; + +/* + ***************************************************************************** + * + * Finite State Machine & Interrupt Routines + * + ***************************************************************************** + */ +static void +mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) +{ + /* + * If state is idle, then this is likely the remnants of an old + * operation that driver has given up on or the user has killed. + * If so, issue the stop condition and go to idle. + */ + if (drv_data->state == MV64XXX_I2C_STATE_IDLE) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + return; + } + + if (drv_data->state == MV64XXX_I2C_STATE_ABORTING) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + return; + } + + /* The status from the ctlr [mostly] tells us what to do next */ + switch (status) { + /* Start condition interrupt */ + case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */ + case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */ + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1; + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK; + break; + + /* Performing a write */ + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */ + case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */ + if (drv_data->bytes_left > 0) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK; + drv_data->bytes_left--; + } else { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + } + break; + + /* Performing a read */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */ + if (drv_data->bytes_left == 0) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */ + if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK) + drv_data->action = MV64XXX_I2C_ACTION_CONTINUE; + else { + drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA; + drv_data->bytes_left--; + } + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA; + + if (drv_data->bytes_left == 1) + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK; + break; + + case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ + drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ + case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ + /* Doesn't seem to be a device at other end */ + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + drv_data->rc = -ENODEV; + break; + + default: + dev_err(&drv_data->adapter.dev, + "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, " + "status: 0x%x, addr: 0x%x, flags: 0x%x\n", + drv_data->state, status, drv_data->msg->addr, + drv_data->msg->flags); + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + drv_data->rc = -EIO; + } +} + +static void +mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) +{ + switch(drv_data->action) { + case MV64XXX_I2C_ACTION_CONTINUE: + writel(drv_data->cntl_bits, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + break; + + case MV64XXX_I2C_ACTION_SEND_START: + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + break; + + case MV64XXX_I2C_ACTION_SEND_ADDR_1: + writel(drv_data->addr1, + drv_data->reg_base + MV64XXX_I2C_REG_DATA); + writel(drv_data->cntl_bits, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + break; + + case MV64XXX_I2C_ACTION_SEND_ADDR_2: + writel(drv_data->addr2, + drv_data->reg_base + MV64XXX_I2C_REG_DATA); + writel(drv_data->cntl_bits, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + break; + + case MV64XXX_I2C_ACTION_SEND_DATA: + writel(drv_data->msg->buf[drv_data->byte_posn++], + drv_data->reg_base + MV64XXX_I2C_REG_DATA); + writel(drv_data->cntl_bits, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + break; + + case MV64XXX_I2C_ACTION_RCV_DATA: + drv_data->msg->buf[drv_data->byte_posn++] = + readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA); + writel(drv_data->cntl_bits, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + break; + + case MV64XXX_I2C_ACTION_RCV_DATA_STOP: + drv_data->msg->buf[drv_data->byte_posn++] = + readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA); + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + drv_data->block = 0; + wake_up_interruptible(&drv_data->waitq); + break; + + case MV64XXX_I2C_ACTION_INVALID: + default: + dev_err(&drv_data->adapter.dev, + "mv64xxx_i2c_do_action: Invalid action: %d\n", + drv_data->action); + drv_data->rc = -EIO; + /* FALLTHRU */ + case MV64XXX_I2C_ACTION_SEND_STOP: + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + drv_data->block = 0; + wake_up_interruptible(&drv_data->waitq); + break; + } +} + +static int +mv64xxx_i2c_intr(int irq, void *dev_id, struct pt_regs *regs) +{ + struct mv64xxx_i2c_data *drv_data = dev_id; + unsigned long flags; + u32 status; + int rc = IRQ_NONE; + + spin_lock_irqsave(&drv_data->lock, flags); + while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) & + MV64XXX_I2C_REG_CONTROL_IFLG) { + status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS); + mv64xxx_i2c_fsm(drv_data, status); + mv64xxx_i2c_do_action(drv_data); + rc = IRQ_HANDLED; + } + spin_unlock_irqrestore(&drv_data->lock, flags); + + return rc; +} + +/* + ***************************************************************************** + * + * I2C Msg Execution Routines + * + ***************************************************************************** + */ +static void +mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data, + struct i2c_msg *msg) +{ + u32 dir = 0; + + drv_data->msg = msg; + drv_data->byte_posn = 0; + drv_data->bytes_left = msg->len; + drv_data->rc = 0; + drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK | + MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN; + + if (msg->flags & I2C_M_RD) + dir = 1; + + if (msg->flags & I2C_M_REV_DIR_ADDR) + dir ^= 1; + + if (msg->flags & I2C_M_TEN) { + drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir; + drv_data->addr2 = (u32)msg->addr & 0xff; + } else { + drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir; + drv_data->addr2 = 0; + } +} + +static void +mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) +{ + long time_left; + unsigned long flags; + char abort = 0; + + time_left = wait_event_interruptible_timeout(drv_data->waitq, + !drv_data->block, msecs_to_jiffies(drv_data->adapter.timeout)); + + spin_lock_irqsave(&drv_data->lock, flags); + if (!time_left) { /* Timed out */ + drv_data->rc = -ETIMEDOUT; + abort = 1; + } else if (time_left < 0) { /* Interrupted/Error */ + drv_data->rc = time_left; /* errno value */ + abort = 1; + } + + if (abort && drv_data->block) { + drv_data->state = MV64XXX_I2C_STATE_ABORTING; + spin_unlock_irqrestore(&drv_data->lock, flags); + + time_left = wait_event_timeout(drv_data->waitq, + !drv_data->block, + msecs_to_jiffies(drv_data->adapter.timeout)); + + if (time_left <= 0) { + drv_data->state = MV64XXX_I2C_STATE_IDLE; + dev_err(&drv_data->adapter.dev, + "mv64xxx: I2C bus locked\n"); + } + } else + spin_unlock_irqrestore(&drv_data->lock, flags); +} + +static int +mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg) +{ + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + mv64xxx_i2c_prepare_for_io(drv_data, msg); + + if (unlikely(msg->flags & I2C_M_NOSTART)) { /* Skip start/addr phases */ + if (drv_data->msg->flags & I2C_M_RD) { + /* No action to do, wait for slave to send a byte */ + drv_data->action = MV64XXX_I2C_ACTION_CONTINUE; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA; + } else { + drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK; + drv_data->bytes_left--; + } + } else { + drv_data->action = MV64XXX_I2C_ACTION_SEND_START; + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND; + } + + drv_data->block = 1; + mv64xxx_i2c_do_action(drv_data); + spin_unlock_irqrestore(&drv_data->lock, flags); + + mv64xxx_i2c_wait_for_completion(drv_data); + return drv_data->rc; +} + +/* + ***************************************************************************** + * + * I2C Core Support Routines (Interface to higher level I2C code) + * + ***************************************************************************** + */ +static u32 +mv64xxx_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL; +} + +static int +mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); + int i, rc = 0; + + for (i=0; i<num; i++) + if ((rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i])) != 0) + break; + + return rc; +} + +static struct i2c_algorithm mv64xxx_i2c_algo = { + .name = MV64XXX_I2C_CTLR_NAME " algorithm", + .id = I2C_ALGO_MV64XXX, + .master_xfer = mv64xxx_i2c_xfer, + .functionality = mv64xxx_i2c_functionality, +}; + +/* + ***************************************************************************** + * + * Driver Interface & Early Init Routines + * + ***************************************************************************** + */ +static void __devinit +mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data) +{ + writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET); + writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)), + drv_data->reg_base + MV64XXX_I2C_REG_BAUD); + writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR); + writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR); + writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); + drv_data->state = MV64XXX_I2C_STATE_IDLE; +} + +static int __devinit +mv64xxx_i2c_map_regs(struct platform_device *pd, + struct mv64xxx_i2c_data *drv_data) +{ + struct resource *r; + + if ((r = platform_get_resource(pd, IORESOURCE_MEM, 0)) && + request_mem_region(r->start, MV64XXX_I2C_REG_BLOCK_SIZE, + drv_data->adapter.name)) { + + drv_data->reg_base = ioremap(r->start, + MV64XXX_I2C_REG_BLOCK_SIZE); + drv_data->reg_base_p = r->start; + } else + return -ENOMEM; + + return 0; +} + +static void __devexit +mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data) +{ + if (drv_data->reg_base) { + iounmap(drv_data->reg_base); + release_mem_region(drv_data->reg_base_p, + MV64XXX_I2C_REG_BLOCK_SIZE); + } + + drv_data->reg_base = NULL; + drv_data->reg_base_p = 0; +} + +static int __devinit +mv64xxx_i2c_probe(struct device *dev) +{ + struct platform_device *pd = to_platform_device(dev); + struct mv64xxx_i2c_data *drv_data; + struct mv64xxx_i2c_pdata *pdata = dev->platform_data; + int rc; + + if ((pd->id != 0) || !pdata) + return -ENODEV; + + drv_data = kmalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL); + + if (!drv_data) + return -ENOMEM; + + memset(drv_data, 0, sizeof(struct mv64xxx_i2c_data)); + + if (mv64xxx_i2c_map_regs(pd, drv_data)) { + rc = -ENODEV; + goto exit_kfree; + } + + strncpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter", + I2C_NAME_SIZE); + + init_waitqueue_head(&drv_data->waitq); + spin_lock_init(&drv_data->lock); + + drv_data->freq_m = pdata->freq_m; + drv_data->freq_n = pdata->freq_n; + drv_data->irq = platform_get_irq(pd, 0); + drv_data->adapter.id = I2C_ALGO_MV64XXX | I2C_HW_MV64XXX; + drv_data->adapter.algo = &mv64xxx_i2c_algo; + drv_data->adapter.owner = THIS_MODULE; + drv_data->adapter.class = I2C_CLASS_HWMON; + drv_data->adapter.timeout = pdata->timeout; + drv_data->adapter.retries = pdata->retries; + dev_set_drvdata(dev, drv_data); + i2c_set_adapdata(&drv_data->adapter, drv_data); + + if (request_irq(drv_data->irq, mv64xxx_i2c_intr, 0, + MV64XXX_I2C_CTLR_NAME, drv_data)) { + + dev_err(dev, "mv64xxx: Can't register intr handler " + "irq: %d\n", drv_data->irq); + rc = -EINVAL; + goto exit_unmap_regs; + } else if ((rc = i2c_add_adapter(&drv_data->adapter)) != 0) { + dev_err(dev, "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc); + goto exit_free_irq; + } + + mv64xxx_i2c_hw_init(drv_data); + + return 0; + + exit_free_irq: + free_irq(drv_data->irq, drv_data); + exit_unmap_regs: + mv64xxx_i2c_unmap_regs(drv_data); + exit_kfree: + kfree(drv_data); + return rc; +} + +static int __devexit +mv64xxx_i2c_remove(struct device *dev) +{ + struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev); + int rc; + + rc = i2c_del_adapter(&drv_data->adapter); + free_irq(drv_data->irq, drv_data); + mv64xxx_i2c_unmap_regs(drv_data); + kfree(drv_data); + + return rc; +} + +static struct device_driver mv64xxx_i2c_driver = { + .name = MV64XXX_I2C_CTLR_NAME, + .bus = &platform_bus_type, + .probe = mv64xxx_i2c_probe, + .remove = mv64xxx_i2c_remove, +}; + +static int __init +mv64xxx_i2c_init(void) +{ + return driver_register(&mv64xxx_i2c_driver); +} + +static void __exit +mv64xxx_i2c_exit(void) +{ + driver_unregister(&mv64xxx_i2c_driver); +} + +module_init(mv64xxx_i2c_init); +module_exit(mv64xxx_i2c_exit); + +MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>"); +MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver"); +MODULE_LICENSE("GPL"); |