diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-bfin-twi.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-bfin-twi.c | 797 |
1 files changed, 797 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c new file mode 100644 index 00000000..cbc98aea --- /dev/null +++ b/drivers/i2c/busses/i2c-bfin-twi.c @@ -0,0 +1,797 @@ +/* + * Blackfin On-Chip Two Wire Interface Driver + * + * Copyright 2005-2007 Analog Devices Inc. + * + * Enter bugs at http://blackfin.uclinux.org/ + * + * Licensed under the GPL-2 or later. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/timer.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/delay.h> + +#include <asm/blackfin.h> +#include <asm/portmux.h> +#include <asm/irq.h> + +/* SMBus mode*/ +#define TWI_I2C_MODE_STANDARD 1 +#define TWI_I2C_MODE_STANDARDSUB 2 +#define TWI_I2C_MODE_COMBINED 3 +#define TWI_I2C_MODE_REPEAT 4 + +struct bfin_twi_iface { + int irq; + spinlock_t lock; + char read_write; + u8 command; + u8 *transPtr; + int readNum; + int writeNum; + int cur_mode; + int manual_stop; + int result; + struct i2c_adapter adap; + struct completion complete; + struct i2c_msg *pmsg; + int msg_num; + int cur_msg; + u16 saved_clkdiv; + u16 saved_control; + void __iomem *regs_base; +}; + + +#define DEFINE_TWI_REG(reg, off) \ +static inline u16 read_##reg(struct bfin_twi_iface *iface) \ + { return bfin_read16(iface->regs_base + (off)); } \ +static inline void write_##reg(struct bfin_twi_iface *iface, u16 v) \ + { bfin_write16(iface->regs_base + (off), v); } + +DEFINE_TWI_REG(CLKDIV, 0x00) +DEFINE_TWI_REG(CONTROL, 0x04) +DEFINE_TWI_REG(SLAVE_CTL, 0x08) +DEFINE_TWI_REG(SLAVE_STAT, 0x0C) +DEFINE_TWI_REG(SLAVE_ADDR, 0x10) +DEFINE_TWI_REG(MASTER_CTL, 0x14) +DEFINE_TWI_REG(MASTER_STAT, 0x18) +DEFINE_TWI_REG(MASTER_ADDR, 0x1C) +DEFINE_TWI_REG(INT_STAT, 0x20) +DEFINE_TWI_REG(INT_MASK, 0x24) +DEFINE_TWI_REG(FIFO_CTL, 0x28) +DEFINE_TWI_REG(FIFO_STAT, 0x2C) +DEFINE_TWI_REG(XMT_DATA8, 0x80) +DEFINE_TWI_REG(XMT_DATA16, 0x84) +DEFINE_TWI_REG(RCV_DATA8, 0x88) +DEFINE_TWI_REG(RCV_DATA16, 0x8C) + +static const u16 pin_req[2][3] = { + {P_TWI0_SCL, P_TWI0_SDA, 0}, + {P_TWI1_SCL, P_TWI1_SDA, 0}, +}; + +static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface, + unsigned short twi_int_status) +{ + unsigned short mast_stat = read_MASTER_STAT(iface); + + if (twi_int_status & XMTSERV) { + /* Transmit next data */ + if (iface->writeNum > 0) { + SSYNC(); + write_XMT_DATA8(iface, *(iface->transPtr++)); + iface->writeNum--; + } + /* start receive immediately after complete sending in + * combine mode. + */ + else if (iface->cur_mode == TWI_I2C_MODE_COMBINED) + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) | MDIR | RSTART); + else if (iface->manual_stop) + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) | STOP); + else if (iface->cur_mode == TWI_I2C_MODE_REPEAT && + iface->cur_msg + 1 < iface->msg_num) { + if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD) + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) | RSTART | MDIR); + else + write_MASTER_CTL(iface, + (read_MASTER_CTL(iface) | RSTART) & ~MDIR); + } + } + if (twi_int_status & RCVSERV) { + if (iface->readNum > 0) { + /* Receive next data */ + *(iface->transPtr) = read_RCV_DATA8(iface); + if (iface->cur_mode == TWI_I2C_MODE_COMBINED) { + /* Change combine mode into sub mode after + * read first data. + */ + iface->cur_mode = TWI_I2C_MODE_STANDARDSUB; + /* Get read number from first byte in block + * combine mode. + */ + if (iface->readNum == 1 && iface->manual_stop) + iface->readNum = *iface->transPtr + 1; + } + iface->transPtr++; + iface->readNum--; + } else if (iface->manual_stop) { + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) | STOP); + } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT && + iface->cur_msg + 1 < iface->msg_num) { + if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD) + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) | RSTART | MDIR); + else + write_MASTER_CTL(iface, + (read_MASTER_CTL(iface) | RSTART) & ~MDIR); + } + } + if (twi_int_status & MERR) { + write_INT_MASK(iface, 0); + write_MASTER_STAT(iface, 0x3e); + write_MASTER_CTL(iface, 0); + iface->result = -EIO; + + if (mast_stat & LOSTARB) + dev_dbg(&iface->adap.dev, "Lost Arbitration\n"); + if (mast_stat & ANAK) + dev_dbg(&iface->adap.dev, "Address Not Acknowledged\n"); + if (mast_stat & DNAK) + dev_dbg(&iface->adap.dev, "Data Not Acknowledged\n"); + if (mast_stat & BUFRDERR) + dev_dbg(&iface->adap.dev, "Buffer Read Error\n"); + if (mast_stat & BUFWRERR) + dev_dbg(&iface->adap.dev, "Buffer Write Error\n"); + + /* Faulty slave devices, may drive SDA low after a transfer + * finishes. To release the bus this code generates up to 9 + * extra clocks until SDA is released. + */ + + if (read_MASTER_STAT(iface) & SDASEN) { + int cnt = 9; + do { + write_MASTER_CTL(iface, SCLOVR); + udelay(6); + write_MASTER_CTL(iface, 0); + udelay(6); + } while ((read_MASTER_STAT(iface) & SDASEN) && cnt--); + + write_MASTER_CTL(iface, SDAOVR | SCLOVR); + udelay(6); + write_MASTER_CTL(iface, SDAOVR); + udelay(6); + write_MASTER_CTL(iface, 0); + } + + /* If it is a quick transfer, only address without data, + * not an err, return 1. + */ + if (iface->cur_mode == TWI_I2C_MODE_STANDARD && + iface->transPtr == NULL && + (twi_int_status & MCOMP) && (mast_stat & DNAK)) + iface->result = 1; + + complete(&iface->complete); + return; + } + if (twi_int_status & MCOMP) { + if ((read_MASTER_CTL(iface) & MEN) == 0 && + (iface->cur_mode == TWI_I2C_MODE_REPEAT || + iface->cur_mode == TWI_I2C_MODE_COMBINED)) { + iface->result = -1; + write_INT_MASK(iface, 0); + write_MASTER_CTL(iface, 0); + } else if (iface->cur_mode == TWI_I2C_MODE_COMBINED) { + if (iface->readNum == 0) { + /* set the read number to 1 and ask for manual + * stop in block combine mode + */ + iface->readNum = 1; + iface->manual_stop = 1; + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) | (0xff << 6)); + } else { + /* set the readd number in other + * combine mode. + */ + write_MASTER_CTL(iface, + (read_MASTER_CTL(iface) & + (~(0xff << 6))) | + (iface->readNum << 6)); + } + /* remove restart bit and enable master receive */ + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) & ~RSTART); + } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT && + iface->cur_msg+1 < iface->msg_num) { + iface->cur_msg++; + iface->transPtr = iface->pmsg[iface->cur_msg].buf; + iface->writeNum = iface->readNum = + iface->pmsg[iface->cur_msg].len; + /* Set Transmit device address */ + write_MASTER_ADDR(iface, + iface->pmsg[iface->cur_msg].addr); + if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD) + iface->read_write = I2C_SMBUS_READ; + else { + iface->read_write = I2C_SMBUS_WRITE; + /* Transmit first data */ + if (iface->writeNum > 0) { + write_XMT_DATA8(iface, + *(iface->transPtr++)); + iface->writeNum--; + } + } + + if (iface->pmsg[iface->cur_msg].len <= 255) + write_MASTER_CTL(iface, + (read_MASTER_CTL(iface) & + (~(0xff << 6))) | + (iface->pmsg[iface->cur_msg].len << 6)); + else { + write_MASTER_CTL(iface, + (read_MASTER_CTL(iface) | + (0xff << 6))); + iface->manual_stop = 1; + } + /* remove restart bit and enable master receive */ + write_MASTER_CTL(iface, + read_MASTER_CTL(iface) & ~RSTART); + } else { + iface->result = 1; + write_INT_MASK(iface, 0); + write_MASTER_CTL(iface, 0); + } + } + complete(&iface->complete); +} + +/* Interrupt handler */ +static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id) +{ + struct bfin_twi_iface *iface = dev_id; + unsigned long flags; + unsigned short twi_int_status; + + spin_lock_irqsave(&iface->lock, flags); + while (1) { + twi_int_status = read_INT_STAT(iface); + if (!twi_int_status) + break; + /* Clear interrupt status */ + write_INT_STAT(iface, twi_int_status); + bfin_twi_handle_interrupt(iface, twi_int_status); + SSYNC(); + } + spin_unlock_irqrestore(&iface->lock, flags); + return IRQ_HANDLED; +} + +/* + * One i2c master transfer + */ +static int bfin_twi_do_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct bfin_twi_iface *iface = adap->algo_data; + struct i2c_msg *pmsg; + int rc = 0; + + if (!(read_CONTROL(iface) & TWI_ENA)) + return -ENXIO; + + while (read_MASTER_STAT(iface) & BUSBUSY) + yield(); + + iface->pmsg = msgs; + iface->msg_num = num; + iface->cur_msg = 0; + + pmsg = &msgs[0]; + if (pmsg->flags & I2C_M_TEN) { + dev_err(&adap->dev, "10 bits addr not supported!\n"); + return -EINVAL; + } + + iface->cur_mode = TWI_I2C_MODE_REPEAT; + iface->manual_stop = 0; + iface->transPtr = pmsg->buf; + iface->writeNum = iface->readNum = pmsg->len; + iface->result = 0; + init_completion(&(iface->complete)); + /* Set Transmit device address */ + write_MASTER_ADDR(iface, pmsg->addr); + + /* FIFO Initiation. Data in FIFO should be + * discarded before start a new operation. + */ + write_FIFO_CTL(iface, 0x3); + SSYNC(); + write_FIFO_CTL(iface, 0); + SSYNC(); + + if (pmsg->flags & I2C_M_RD) + iface->read_write = I2C_SMBUS_READ; + else { + iface->read_write = I2C_SMBUS_WRITE; + /* Transmit first data */ + if (iface->writeNum > 0) { + write_XMT_DATA8(iface, *(iface->transPtr++)); + iface->writeNum--; + SSYNC(); + } + } + + /* clear int stat */ + write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV); + + /* Interrupt mask . Enable XMT, RCV interrupt */ + write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV); + SSYNC(); + + if (pmsg->len <= 255) + write_MASTER_CTL(iface, pmsg->len << 6); + else { + write_MASTER_CTL(iface, 0xff << 6); + iface->manual_stop = 1; + } + + /* Master enable */ + write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN | + ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) | + ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0)); + SSYNC(); + + while (!iface->result) { + if (!wait_for_completion_timeout(&iface->complete, + adap->timeout)) { + iface->result = -1; + dev_err(&adap->dev, "master transfer timeout\n"); + } + } + + if (iface->result == 1) + rc = iface->cur_msg + 1; + else + rc = iface->result; + + return rc; +} + +/* + * Generic i2c master transfer entrypoint + */ +static int bfin_twi_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + return bfin_twi_do_master_xfer(adap, msgs, num); +} + +/* + * One I2C SMBus transfer + */ +int bfin_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data *data) +{ + struct bfin_twi_iface *iface = adap->algo_data; + int rc = 0; + + if (!(read_CONTROL(iface) & TWI_ENA)) + return -ENXIO; + + while (read_MASTER_STAT(iface) & BUSBUSY) + yield(); + + iface->writeNum = 0; + iface->readNum = 0; + + /* Prepare datas & select mode */ + switch (size) { + case I2C_SMBUS_QUICK: + iface->transPtr = NULL; + iface->cur_mode = TWI_I2C_MODE_STANDARD; + break; + case I2C_SMBUS_BYTE: + if (data == NULL) + iface->transPtr = NULL; + else { + if (read_write == I2C_SMBUS_READ) + iface->readNum = 1; + else + iface->writeNum = 1; + iface->transPtr = &data->byte; + } + iface->cur_mode = TWI_I2C_MODE_STANDARD; + break; + case I2C_SMBUS_BYTE_DATA: + if (read_write == I2C_SMBUS_READ) { + iface->readNum = 1; + iface->cur_mode = TWI_I2C_MODE_COMBINED; + } else { + iface->writeNum = 1; + iface->cur_mode = TWI_I2C_MODE_STANDARDSUB; + } + iface->transPtr = &data->byte; + break; + case I2C_SMBUS_WORD_DATA: + if (read_write == I2C_SMBUS_READ) { + iface->readNum = 2; + iface->cur_mode = TWI_I2C_MODE_COMBINED; + } else { + iface->writeNum = 2; + iface->cur_mode = TWI_I2C_MODE_STANDARDSUB; + } + iface->transPtr = (u8 *)&data->word; + break; + case I2C_SMBUS_PROC_CALL: + iface->writeNum = 2; + iface->readNum = 2; + iface->cur_mode = TWI_I2C_MODE_COMBINED; + iface->transPtr = (u8 *)&data->word; + break; + case I2C_SMBUS_BLOCK_DATA: + if (read_write == I2C_SMBUS_READ) { + iface->readNum = 0; + iface->cur_mode = TWI_I2C_MODE_COMBINED; + } else { + iface->writeNum = data->block[0] + 1; + iface->cur_mode = TWI_I2C_MODE_STANDARDSUB; + } + iface->transPtr = data->block; + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + if (read_write == I2C_SMBUS_READ) { + iface->readNum = data->block[0]; + iface->cur_mode = TWI_I2C_MODE_COMBINED; + } else { + iface->writeNum = data->block[0]; + iface->cur_mode = TWI_I2C_MODE_STANDARDSUB; + } + iface->transPtr = (u8 *)&data->block[1]; + break; + default: + return -1; + } + + iface->result = 0; + iface->manual_stop = 0; + iface->read_write = read_write; + iface->command = command; + init_completion(&(iface->complete)); + + /* FIFO Initiation. Data in FIFO should be discarded before + * start a new operation. + */ + write_FIFO_CTL(iface, 0x3); + SSYNC(); + write_FIFO_CTL(iface, 0); + + /* clear int stat */ + write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV); + + /* Set Transmit device address */ + write_MASTER_ADDR(iface, addr); + SSYNC(); + + switch (iface->cur_mode) { + case TWI_I2C_MODE_STANDARDSUB: + write_XMT_DATA8(iface, iface->command); + write_INT_MASK(iface, MCOMP | MERR | + ((iface->read_write == I2C_SMBUS_READ) ? + RCVSERV : XMTSERV)); + SSYNC(); + + if (iface->writeNum + 1 <= 255) + write_MASTER_CTL(iface, (iface->writeNum + 1) << 6); + else { + write_MASTER_CTL(iface, 0xff << 6); + iface->manual_stop = 1; + } + /* Master enable */ + write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN | + ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0)); + break; + case TWI_I2C_MODE_COMBINED: + write_XMT_DATA8(iface, iface->command); + write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV); + SSYNC(); + + if (iface->writeNum > 0) + write_MASTER_CTL(iface, (iface->writeNum + 1) << 6); + else + write_MASTER_CTL(iface, 0x1 << 6); + /* Master enable */ + write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN | + ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0)); + break; + default: + write_MASTER_CTL(iface, 0); + if (size != I2C_SMBUS_QUICK) { + /* Don't access xmit data register when this is a + * read operation. + */ + if (iface->read_write != I2C_SMBUS_READ) { + if (iface->writeNum > 0) { + write_XMT_DATA8(iface, + *(iface->transPtr++)); + if (iface->writeNum <= 255) + write_MASTER_CTL(iface, + iface->writeNum << 6); + else { + write_MASTER_CTL(iface, + 0xff << 6); + iface->manual_stop = 1; + } + iface->writeNum--; + } else { + write_XMT_DATA8(iface, iface->command); + write_MASTER_CTL(iface, 1 << 6); + } + } else { + if (iface->readNum > 0 && iface->readNum <= 255) + write_MASTER_CTL(iface, + iface->readNum << 6); + else if (iface->readNum > 255) { + write_MASTER_CTL(iface, 0xff << 6); + iface->manual_stop = 1; + } else + break; + } + } + write_INT_MASK(iface, MCOMP | MERR | + ((iface->read_write == I2C_SMBUS_READ) ? + RCVSERV : XMTSERV)); + SSYNC(); + + /* Master enable */ + write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN | + ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) | + ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0)); + break; + } + SSYNC(); + + while (!iface->result) { + if (!wait_for_completion_timeout(&iface->complete, + adap->timeout)) { + iface->result = -1; + dev_err(&adap->dev, "smbus transfer timeout\n"); + } + } + + rc = (iface->result >= 0) ? 0 : -1; + + return rc; +} + +/* + * Generic I2C SMBus transfer entrypoint + */ +int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data *data) +{ + return bfin_twi_do_smbus_xfer(adap, addr, flags, + read_write, command, size, data); +} + +/* + * Return what the adapter supports + */ +static u32 bfin_twi_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL | + I2C_FUNC_I2C | I2C_FUNC_SMBUS_I2C_BLOCK; +} + +static struct i2c_algorithm bfin_twi_algorithm = { + .master_xfer = bfin_twi_master_xfer, + .smbus_xfer = bfin_twi_smbus_xfer, + .functionality = bfin_twi_functionality, +}; + +static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct bfin_twi_iface *iface = platform_get_drvdata(pdev); + + iface->saved_clkdiv = read_CLKDIV(iface); + iface->saved_control = read_CONTROL(iface); + + free_irq(iface->irq, iface); + + /* Disable TWI */ + write_CONTROL(iface, iface->saved_control & ~TWI_ENA); + + return 0; +} + +static int i2c_bfin_twi_resume(struct platform_device *pdev) +{ + struct bfin_twi_iface *iface = platform_get_drvdata(pdev); + + int rc = request_irq(iface->irq, bfin_twi_interrupt_entry, + IRQF_DISABLED, pdev->name, iface); + if (rc) { + dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq); + return -ENODEV; + } + + /* Resume TWI interface clock as specified */ + write_CLKDIV(iface, iface->saved_clkdiv); + + /* Resume TWI */ + write_CONTROL(iface, iface->saved_control); + + return 0; +} + +static int i2c_bfin_twi_probe(struct platform_device *pdev) +{ + struct bfin_twi_iface *iface; + struct i2c_adapter *p_adap; + struct resource *res; + int rc; + unsigned int clkhilow; + + iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL); + if (!iface) { + dev_err(&pdev->dev, "Cannot allocate memory\n"); + rc = -ENOMEM; + goto out_error_nomem; + } + + spin_lock_init(&(iface->lock)); + + /* Find and map our resources */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); + rc = -ENOENT; + goto out_error_get_res; + } + + iface->regs_base = ioremap(res->start, resource_size(res)); + if (iface->regs_base == NULL) { + dev_err(&pdev->dev, "Cannot map IO\n"); + rc = -ENXIO; + goto out_error_ioremap; + } + + iface->irq = platform_get_irq(pdev, 0); + if (iface->irq < 0) { + dev_err(&pdev->dev, "No IRQ specified\n"); + rc = -ENOENT; + goto out_error_no_irq; + } + + p_adap = &iface->adap; + p_adap->nr = pdev->id; + strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name)); + p_adap->algo = &bfin_twi_algorithm; + p_adap->algo_data = iface; + p_adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + p_adap->dev.parent = &pdev->dev; + p_adap->timeout = 5 * HZ; + p_adap->retries = 3; + + rc = peripheral_request_list(pin_req[pdev->id], "i2c-bfin-twi"); + if (rc) { + dev_err(&pdev->dev, "Can't setup pin mux!\n"); + goto out_error_pin_mux; + } + + rc = request_irq(iface->irq, bfin_twi_interrupt_entry, + IRQF_DISABLED, pdev->name, iface); + if (rc) { + dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq); + rc = -ENODEV; + goto out_error_req_irq; + } + + /* Set TWI internal clock as 10MHz */ + write_CONTROL(iface, ((get_sclk() / 1000 / 1000 + 5) / 10) & 0x7F); + + /* + * We will not end up with a CLKDIV=0 because no one will specify + * 20kHz SCL or less in Kconfig now. (5 * 1000 / 20 = 250) + */ + clkhilow = ((10 * 1000 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) + 1) / 2; + + /* Set Twi interface clock as specified */ + write_CLKDIV(iface, (clkhilow << 8) | clkhilow); + + /* Enable TWI */ + write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA); + SSYNC(); + + rc = i2c_add_numbered_adapter(p_adap); + if (rc < 0) { + dev_err(&pdev->dev, "Can't add i2c adapter!\n"); + goto out_error_add_adapter; + } + + platform_set_drvdata(pdev, iface); + + dev_info(&pdev->dev, "Blackfin BF5xx on-chip I2C TWI Contoller, " + "regs_base@%p\n", iface->regs_base); + + return 0; + +out_error_add_adapter: + free_irq(iface->irq, iface); +out_error_req_irq: +out_error_no_irq: + peripheral_free_list(pin_req[pdev->id]); +out_error_pin_mux: + iounmap(iface->regs_base); +out_error_ioremap: +out_error_get_res: + kfree(iface); +out_error_nomem: + return rc; +} + +static int i2c_bfin_twi_remove(struct platform_device *pdev) +{ + struct bfin_twi_iface *iface = platform_get_drvdata(pdev); + + platform_set_drvdata(pdev, NULL); + + i2c_del_adapter(&(iface->adap)); + free_irq(iface->irq, iface); + peripheral_free_list(pin_req[pdev->id]); + iounmap(iface->regs_base); + kfree(iface); + + return 0; +} + +static struct platform_driver i2c_bfin_twi_driver = { + .probe = i2c_bfin_twi_probe, + .remove = i2c_bfin_twi_remove, + .suspend = i2c_bfin_twi_suspend, + .resume = i2c_bfin_twi_resume, + .driver = { + .name = "i2c-bfin-twi", + .owner = THIS_MODULE, + }, +}; + +static int __init i2c_bfin_twi_init(void) +{ + return platform_driver_register(&i2c_bfin_twi_driver); +} + +static void __exit i2c_bfin_twi_exit(void) +{ + platform_driver_unregister(&i2c_bfin_twi_driver); +} + +subsys_initcall(i2c_bfin_twi_init); +module_exit(i2c_bfin_twi_exit); + +MODULE_AUTHOR("Bryan Wu, Sonic Zhang"); +MODULE_DESCRIPTION("Blackfin BF5xx on-chip I2C TWI Contoller Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:i2c-bfin-twi"); |