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authorSonic Zhang <sonic.zhang@analog.com>2010-03-22 03:23:16 -0400
committerBen Dooks <ben-linux@fluff.org>2010-05-20 00:18:58 +0100
commitdd7319a5289deb4e17beb8851d343e7930b32c3b (patch)
tree6d6d7ba0727debac654901402fdcbeaad5f931f2 /drivers/i2c
parent1bc2962e530527de829bf4b1eb99f24dc25d1828 (diff)
i2c-bfin-twi: integrate timeout timer with completion interface
There isn't much point in managing our own custom timeout timer when the completion interface already includes support for it. This makes the resulting code much simpler and robust. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-bfin-twi.c125
1 files changed, 66 insertions, 59 deletions
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index f1e14dd590c..441134a1df9 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;
@@ -169,16 +165,13 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
write_INT_MASK(iface, 0);
write_MASTER_CTL(iface, 0);
SSYNC();
- /* If it is a quick transfer, only address bug no data,
+ /* If it is a quick transfer, only address without data,
* not an err, return 1.
+ * If address is acknowledged return 1.
*/
- if (iface->writeNum == 0 && (mast_stat & BUFRDERR))
+ if ((iface->writeNum == 0 && (mast_stat & BUFRDERR))
+ || !(mast_stat & ANAK))
iface->result = 1;
- /* If address not acknowledged return -1,
- * else return 0.
- */
- else if (!(mast_stat & ANAK))
- iface->result = 0;
}
complete(&iface->complete);
return;
@@ -250,9 +243,9 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
write_INT_MASK(iface, 0);
write_MASTER_CTL(iface, 0);
SSYNC();
- complete(&iface->complete);
}
}
+ complete(&iface->complete);
}
/* Interrupt handler */
@@ -262,36 +255,15 @@ static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
unsigned long flags;
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);
- }
- }
- spin_unlock_irqrestore(&iface->lock, flags);
-}
-
/*
- * 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 +291,6 @@ 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 +329,49 @@ 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)
+{
+ int i, ret = 0;
-int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
+ for (i = 0; i < adap->retries; i++) {
+ ret = bfin_twi_do_master_xfer(adap, msgs, num);
+ if (ret > 0)
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * 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 +459,6 @@ 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 +475,6 @@ 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 +536,8 @@ 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 +553,13 @@ 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 +567,25 @@ 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)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < adap->retries; i++) {
+ ret = bfin_twi_do_smbus_xfer(adap, addr, flags,
+ read_write, command, size, data);
+ if (ret == 0)
+ break;
+ }
+
+ return ret;
+}
+
+/*
* Return what the adapter supports
*/
static u32 bfin_twi_functionality(struct i2c_adapter *adap)
@@ -667,10 +676,6 @@ 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 +683,8 @@ 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) {