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path: root/drivers/i2c/busses/i2c-bfin-twi.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-bfin-twi.c')
-rw-r--r--drivers/i2c/busses/i2c-bfin-twi.c168
1 files changed, 78 insertions, 90 deletions
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index f1e14dd..fb26e5c 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -25,8 +25,6 @@
#include <asm/portmux.h>
#include <asm/irq.h>
-#define POLL_TIMEOUT (2 * HZ)
-
/* SMBus mode*/
#define TWI_I2C_MODE_STANDARD 1
#define TWI_I2C_MODE_STANDARDSUB 2
@@ -44,8 +42,6 @@ struct bfin_twi_iface {
int cur_mode;
int manual_stop;
int result;
- int timeout_count;
- struct timer_list timeout_timer;
struct i2c_adapter adap;
struct completion complete;
struct i2c_msg *pmsg;
@@ -85,14 +81,15 @@ static const u16 pin_req[2][3] = {
{P_TWI1_SCL, P_TWI1_SDA, 0},
};
-static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
+static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface,
+ unsigned short twi_int_status)
{
- unsigned short twi_int_status = read_INT_STAT(iface);
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--;
}
@@ -114,10 +111,6 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
write_MASTER_CTL(iface,
(read_MASTER_CTL(iface) | RSTART) & ~MDIR);
}
- SSYNC();
- /* Clear status */
- write_INT_STAT(iface, XMTSERV);
- SSYNC();
}
if (twi_int_status & RCVSERV) {
if (iface->readNum > 0) {
@@ -139,7 +132,6 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
} else if (iface->manual_stop) {
write_MASTER_CTL(iface,
read_MASTER_CTL(iface) | STOP);
- SSYNC();
} 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)
@@ -148,44 +140,37 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
else
write_MASTER_CTL(iface,
(read_MASTER_CTL(iface) | RSTART) & ~MDIR);
- SSYNC();
}
- /* Clear interrupt source */
- write_INT_STAT(iface, RCVSERV);
- SSYNC();
}
if (twi_int_status & MERR) {
- write_INT_STAT(iface, MERR);
write_INT_MASK(iface, 0);
write_MASTER_STAT(iface, 0x3e);
write_MASTER_CTL(iface, 0);
- SSYNC();
iface->result = -EIO;
- /* if both err and complete int stats are set, return proper
- * results.
+
+ 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");
+
+ /* If it is a quick transfer, only address without data,
+ * not an err, return 1.
*/
- if (twi_int_status & MCOMP) {
- write_INT_STAT(iface, MCOMP);
- write_INT_MASK(iface, 0);
- write_MASTER_CTL(iface, 0);
- SSYNC();
- /* If it is a quick transfer, only address bug no data,
- * not an err, return 1.
- */
- if (iface->writeNum == 0 && (mast_stat & BUFRDERR))
- iface->result = 1;
- /* If address not acknowledged return -1,
- * else return 0.
- */
- else if (!(mast_stat & ANAK))
- iface->result = 0;
- }
+ 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) {
- write_INT_STAT(iface, MCOMP);
- SSYNC();
if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
if (iface->readNum == 0) {
/* set the read number to 1 and ask for manual
@@ -207,7 +192,6 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
/* remove restart bit and enable master receive */
write_MASTER_CTL(iface,
read_MASTER_CTL(iface) & ~RSTART);
- SSYNC();
} else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
iface->cur_msg+1 < iface->msg_num) {
iface->cur_msg++;
@@ -226,7 +210,6 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
write_XMT_DATA8(iface,
*(iface->transPtr++));
iface->writeNum--;
- SSYNC();
}
}
@@ -244,15 +227,13 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
/* remove restart bit and enable master receive */
write_MASTER_CTL(iface,
read_MASTER_CTL(iface) & ~RSTART);
- SSYNC();
} else {
iface->result = 1;
write_INT_MASK(iface, 0);
write_MASTER_CTL(iface, 0);
- SSYNC();
- complete(&iface->complete);
}
}
+ complete(&iface->complete);
}
/* Interrupt handler */
@@ -260,38 +241,26 @@ 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);
- del_timer(&iface->timeout_timer);
- bfin_twi_handle_interrupt(iface);
- spin_unlock_irqrestore(&iface->lock, flags);
- return IRQ_HANDLED;
-}
-
-static void bfin_twi_timeout(unsigned long data)
-{
- struct bfin_twi_iface *iface = (struct bfin_twi_iface *)data;
- unsigned long flags;
-
- spin_lock_irqsave(&iface->lock, flags);
- bfin_twi_handle_interrupt(iface);
- if (iface->result == 0) {
- iface->timeout_count--;
- if (iface->timeout_count > 0) {
- iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
- add_timer(&iface->timeout_timer);
- } else {
- iface->result = -1;
- complete(&iface->complete);
- }
+ 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;
}
/*
- * Generic i2c master transfer entrypoint
+ * One i2c master transfer
*/
-static int bfin_twi_master_xfer(struct i2c_adapter *adap,
+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;
@@ -319,7 +288,6 @@ static int bfin_twi_master_xfer(struct i2c_adapter *adap,
iface->transPtr = pmsg->buf;
iface->writeNum = iface->readNum = pmsg->len;
iface->result = 0;
- iface->timeout_count = 10;
init_completion(&(iface->complete));
/* Set Transmit device address */
write_MASTER_ADDR(iface, pmsg->addr);
@@ -358,30 +326,41 @@ static int bfin_twi_master_xfer(struct i2c_adapter *adap,
iface->manual_stop = 1;
}
- iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
- add_timer(&iface->timeout_timer);
-
/* 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();
- wait_for_completion(&iface->complete);
-
- rc = iface->result;
+ while (!iface->result) {
+ if (!wait_for_completion_timeout(&iface->complete,
+ adap->timeout)) {
+ iface->result = -1;
+ dev_err(&adap->dev, "master transfer timeout\n");
+ }
+ }
- if (rc == 1)
- return num;
+ if (iface->result == 1)
+ rc = iface->cur_msg + 1;
else
- return rc;
+ rc = iface->result;
+
+ return rc;
}
/*
- * SMBus type transfer entrypoint
+ * 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);
+}
-int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
+/*
+ * 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)
{
@@ -469,7 +448,6 @@ int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
iface->manual_stop = 0;
iface->read_write = read_write;
iface->command = command;
- iface->timeout_count = 10;
init_completion(&(iface->complete));
/* FIFO Initiation. Data in FIFO should be discarded before
@@ -486,9 +464,6 @@ int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
write_MASTER_ADDR(iface, addr);
SSYNC();
- iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
- add_timer(&iface->timeout_timer);
-
switch (iface->cur_mode) {
case TWI_I2C_MODE_STANDARDSUB:
write_XMT_DATA8(iface, iface->command);
@@ -550,10 +525,8 @@ int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
else if (iface->readNum > 255) {
write_MASTER_CTL(iface, 0xff << 6);
iface->manual_stop = 1;
- } else {
- del_timer(&iface->timeout_timer);
+ } else
break;
- }
}
}
write_INT_MASK(iface, MCOMP | MERR |
@@ -569,7 +542,13 @@ int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
}
SSYNC();
- wait_for_completion(&iface->complete);
+ 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;
@@ -577,6 +556,17 @@ int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
}
/*
+ * 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)
@@ -667,10 +657,6 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
goto out_error_no_irq;
}
- init_timer(&(iface->timeout_timer));
- iface->timeout_timer.function = bfin_twi_timeout;
- iface->timeout_timer.data = (unsigned long)iface;
-
p_adap = &iface->adap;
p_adap->nr = pdev->id;
strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name));
@@ -678,6 +664,8 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
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) {