On Tue, 24 Feb 2009 17:22:15 +0100, Wolfram Sang wrote:
> We now timeout also if the state machine does not change within the
> given time. For that, the driver-specific completion-functions are
> extended to return true or false depending on the timeout. This then
> gets checked in the algorithm.
>
> Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
> ---
> drivers/i2c/algos/i2c-algo-pca.c | 39 +++++++++++++++++---------------
> drivers/i2c/busses/i2c-pca-isa.c | 18 +++++++++++----
> drivers/i2c/busses/i2c-pca-platform.c | 20 ++++++++--------
> 3 files changed, 44 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
> index 59ee88a..4153aff 100644
> --- a/drivers/i2c/algos/i2c-algo-pca.c
> +++ b/drivers/i2c/algos/i2c-algo-pca.c
> @@ -60,14 +60,14 @@ static void pca9665_reset(void *pd)
> *
> * returns after the start condition has occurred
> */
> -static void pca_start(struct i2c_algo_pca_data *adap)
> +static int pca_start(struct i2c_algo_pca_data *adap)
> {
> int sta = pca_get_con(adap);
> DEB2("=== START\n");
> sta |= I2C_PCA_CON_STA;
> sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
> pca_set_con(adap, sta);
> - pca_wait(adap);
> + return pca_wait(adap);
> }
>
> /*
> @@ -75,14 +75,14 @@ static void pca_start(struct i2c_algo_pca_data *adap)
> *
> * return after the repeated start condition has occurred
> */
> -static void pca_repeated_start(struct i2c_algo_pca_data *adap)
> +static int pca_repeated_start(struct i2c_algo_pca_data *adap)
> {
> int sta = pca_get_con(adap);
> DEB2("=== REPEATED START\n");
> sta |= I2C_PCA_CON_STA;
> sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
> pca_set_con(adap, sta);
> - pca_wait(adap);
> + return pca_wait(adap);
> }
>
> /*
> @@ -108,7 +108,7 @@ static void pca_stop(struct i2c_algo_pca_data *adap)
> *
> * returns after the address has been sent
> */
> -static void pca_address(struct i2c_algo_pca_data *adap,
> +static int pca_address(struct i2c_algo_pca_data *adap,
> struct i2c_msg *msg)
> {
> int sta = pca_get_con(adap);
> @@ -125,7 +125,7 @@ static void pca_address(struct i2c_algo_pca_data *adap,
> sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
> pca_set_con(adap, sta);
>
> - pca_wait(adap);
> + return pca_wait(adap);
> }
>
> /*
> @@ -133,7 +133,7 @@ static void pca_address(struct i2c_algo_pca_data *adap,
> *
> * Returns after the byte has been transmitted
> */
> -static void pca_tx_byte(struct i2c_algo_pca_data *adap,
> +static int pca_tx_byte(struct i2c_algo_pca_data *adap,
> __u8 b)
> {
> int sta = pca_get_con(adap);
> @@ -143,7 +143,7 @@ static void pca_tx_byte(struct i2c_algo_pca_data *adap,
> sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
> pca_set_con(adap, sta);
>
> - pca_wait(adap);
> + return pca_wait(adap);
> }
>
> /*
> @@ -163,7 +163,7 @@ static void pca_rx_byte(struct i2c_algo_pca_data *adap,
> *
> * Returns after next byte has arrived.
> */
> -static void pca_rx_ack(struct i2c_algo_pca_data *adap,
> +static int pca_rx_ack(struct i2c_algo_pca_data *adap,
> int ack)
> {
> int sta = pca_get_con(adap);
> @@ -174,7 +174,7 @@ static void pca_rx_ack(struct i2c_algo_pca_data *adap,
> sta |= I2C_PCA_CON_AA;
>
> pca_set_con(adap, sta);
> - pca_wait(adap);
> + return pca_wait(adap);
> }
>
> static int pca_xfer(struct i2c_adapter *i2c_adap,
> @@ -187,6 +187,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
> int numbytes = 0;
> int state;
> int ret;
> + int completed = 1;
> unsigned long timeout = jiffies + i2c_adap->timeout;
>
> while (pca_status(adap) != 0xf8) {
> @@ -231,18 +232,18 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
>
> switch (state) {
> case 0xf8: /* On reset or stop the bus is idle */
> - pca_start(adap);
> + completed = pca_start(adap);
> break;
>
> case 0x08: /* A START condition has been transmitted */
> case 0x10: /* A repeated start condition has been transmitted */
> - pca_address(adap, msg);
> + completed = pca_address(adap, msg);
> break;
>
> case 0x18: /* SLA+W has been transmitted; ACK has been received */
> case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
> if (numbytes < msg->len) {
> - pca_tx_byte(adap, msg->buf[numbytes]);
> + completed = pca_tx_byte(adap, msg->buf[numbytes]);
> numbytes++;
> break;
> }
> @@ -250,7 +251,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
> if (curmsg == num)
> pca_stop(adap);
> else
> - pca_repeated_start(adap);
> + completed = pca_repeated_start(adap);
> break;
>
> case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
> @@ -259,21 +260,21 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
> goto out;
>
> case 0x40: /* SLA+R has been transmitted; ACK has been received */
> - pca_rx_ack(adap, msg->len > 1);
> + completed = pca_rx_ack(adap, msg->len > 1);
> break;
>
> case 0x50: /* Data bytes has been received; ACK has been returned */
> if (numbytes < msg->len) {
> pca_rx_byte(adap, &msg->buf[numbytes], 1);
> numbytes++;
> - pca_rx_ack(adap, numbytes < msg->len - 1);
> + completed = pca_rx_ack(adap, numbytes < msg->len - 1);
> break;
> }
> curmsg++; numbytes = 0;
> if (curmsg == num)
> pca_stop(adap);
> else
> - pca_repeated_start(adap);
> + completed = pca_repeated_start(adap);
> break;
>
> case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
> @@ -296,7 +297,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
> if (curmsg == num)
> pca_stop(adap);
> else
> - pca_repeated_start(adap);
> + completed = pca_repeated_start(adap);
> } else {
> DEB2("NOT ACK sent after data byte received. "
> "Not final byte. numbytes %d. len %d\n",
> @@ -322,6 +323,8 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
> break;
> }
>
> + if (!completed)
> + goto out;
> }
>
> ret = curmsg;
> diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
> index 84d035c..a523be8 100644
> --- a/drivers/i2c/busses/i2c-pca-isa.c
> +++ b/drivers/i2c/busses/i2c-pca-isa.c
> @@ -23,6 +23,7 @@
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> #include <linux/delay.h>
> +#include <linux/jiffies.h>
> #include <linux/init.h>
> #include <linux/interrupt.h>
> #include <linux/wait.h>
> @@ -43,6 +44,7 @@ static int irq = -1;
> * in the actual clock rate */
> static int clock = 59000;
>
> +static struct i2c_adapter pca_isa_ops;
> static wait_queue_head_t pca_wait;
>
> static void pca_isa_writebyte(void *pd, int reg, int val)
> @@ -68,16 +70,22 @@ static int pca_isa_readbyte(void *pd, int reg)
>
> static int pca_isa_waitforcompletion(void *pd)
> {
> - int ret = 0;
> + long ret = ~0;
> + unsigned long timeout;
>
> if (irq > -1) {
> - ret = wait_event_interruptible(pca_wait,
> - pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI);
> + ret = wait_event_interruptible_timeout(pca_wait,
> + pca_isa_readbyte(pd, I2C_PCA_CON)
> + & I2C_PCA_CON_SI, pca_isa_ops.timeout);
> } else {
> - while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
> + /* Do polling */
> + timeout = jiffies + pca_isa_ops.timeout;
> + while (((pca_isa_readbyte(pd, I2C_PCA_CON)
> + & I2C_PCA_CON_SI) == 0)
> + && (ret = time_before(jiffies, timeout)))
> udelay(100);
> }
> - return ret;
> + return ret > 0;
> }
>
> static void pca_isa_resetchip(void *pd)
> diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c
> index 51d179b..df5e593 100644
> --- a/drivers/i2c/busses/i2c-pca-platform.c
> +++ b/drivers/i2c/busses/i2c-pca-platform.c
> @@ -15,6 +15,7 @@
> #include <linux/init.h>
> #include <linux/slab.h>
> #include <linux/delay.h>
> +#include <linux/jiffies.h>
> #include <linux/errno.h>
> #include <linux/i2c.h>
> #include <linux/interrupt.h>
> @@ -81,24 +82,23 @@ static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
> static int i2c_pca_pf_waitforcompletion(void *pd)
> {
> struct i2c_pca_pf_data *i2c = pd;
> - int ret = 0;
> + long ret = ~0;
> + unsigned long timeout;
>
> if (i2c->irq) {
> - ret = wait_event_interruptible(i2c->wait,
> + ret = wait_event_interruptible_timeout(i2c->wait,
> i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
> - & I2C_PCA_CON_SI);
> + & I2C_PCA_CON_SI, i2c->adap.timeout);
> } else {
> - /*
> - * Do polling...
> - * XXX: Could get stuck in extreme cases!
> - * Maybe add timeout, but using irqs is preferred anyhow.
> - */
> - while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
> + /* Do polling */
> + timeout = jiffies + i2c->adap.timeout;
> + while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
> & I2C_PCA_CON_SI) == 0)
> + && (ret = time_before(jiffies, timeout)))
> udelay(100);
> }
>
> - return ret;
> + return ret > 0;
> }
>
> static void i2c_pca_pf_dummyreset(void *pd)
Looks good. Applied, thanks.
--
Jean Delvare
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
