| Message ID | 1306452353-11611-1-git-send-email-yorksun@freescale.com |
|---|---|
| State | Not Applicable |
| Delegated to: | Kumar Gala |
| Headers | show |
York Sun wrote:
> From: york <yorksun@freescale.com>
You should fix this so that it includes your full name.
On Thu, 2011-05-26 at 17:20 -0700, Tabi Timur-B04825 wrote: > York Sun wrote: > > From: york <yorksun@freescale.com> > > You should fix this so that it includes your full name. > > -- Sure. I can fix it along with other feedback. York
Hello York, York Sun wrote: > From: york <yorksun@freescale.com> > > EEPROM requires tWR for write cycle time. Since there is no other way to > poll if the internal programming ends, wait for 5ms which is the max timing > for AT24C01/02/04/08/16 by default. It can be overridden by defining > CONFIG_I2C_TWR in configuration file if the slowest device has different write > cycle time. > > Signed-off-by: York Sun <yorksun@freescale.com> > --- > README | 7 +++++++ > drivers/i2c/fsl_i2c.c | 9 +++++++++ > 2 files changed, 16 insertions(+), 0 deletions(-) > > diff --git a/README b/README > index 8bb9c8d..83a316c 100644 > --- a/README > +++ b/README > @@ -1717,6 +1717,13 @@ The following options need to be configured: > devices can use either method, but some require one or > the other. > > + CONFIG_I2C_TWR Maybe CONFIG_SYS_I2C_EEPROM_TWR is better? > + > + defining this will override the default write cycle time the default eeprom write cycle time ... > + 5ms which is the default for AT24C01/02/4/08/16. If the > + slowest I2C device has different write cycle time, this > + option should be defined. The unit is microsecond. > + > - SPI Support: CONFIG_SPI > > Enables SPI driver (so far only tested with > diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c > index cb13dee..d192b2a 100644 > --- a/drivers/i2c/fsl_i2c.c > +++ b/drivers/i2c/fsl_i2c.c > @@ -42,6 +42,14 @@ > #define CONFIG_I2C_TIMEOUT 10000 > #endif > > +/* > + * tWR is the write cycle time for EEPROM device > + * in microseconds > + */ > +#ifndef CONFIG_I2C_TWR > +#define CONFIG_I2C_TWR 5000 > +#endif > + > #define I2C_READ_BIT 1 > #define I2C_WRITE_BIT 0 > > @@ -416,6 +424,7 @@ i2c_write(u8 dev, uint addr, int alen, u8 *data, int length) > if (i2c_wait4bus()) /* Wait until STOP */ > debug("i2c_write: wait4bus timed out\n"); > > + udelay(CONFIG_I2C_TWR); > if (i == length) > return 0; > Hmm.. you add this timeout in the i2c driver, which will result in adding this default 5 ms delay for *all* i2c writes, not only for eeprom devices ... why you didn;t add this timeout in cmd_eeprom, where it seems to me is the better place for it? Looking in this common/cmd_eeprom.c there is a CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS define ... is this not adequate? bye, Heiko
On Fri, 2011-05-27 at 08:04 +0200, Heiko Schocher wrote: > Hmm.. you add this timeout in the i2c driver, which will result in > adding this default 5 ms delay for *all* i2c writes, not only for > eeprom devices ... why you didn;t add this timeout in cmd_eeprom, > where it seems to me is the better place for it? Looking in this > common/cmd_eeprom.c there is a CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS > define ... is this not adequate? > You are right. I overlooked CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS and should use this instead. Drop this patch, please. York
diff --git a/README b/README index 8bb9c8d..83a316c 100644 --- a/README +++ b/README @@ -1717,6 +1717,13 @@ The following options need to be configured: devices can use either method, but some require one or the other. + CONFIG_I2C_TWR + + defining this will override the default write cycle time + 5ms which is the default for AT24C01/02/4/08/16. If the + slowest I2C device has different write cycle time, this + option should be defined. The unit is microsecond. + - SPI Support: CONFIG_SPI Enables SPI driver (so far only tested with diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c index cb13dee..d192b2a 100644 --- a/drivers/i2c/fsl_i2c.c +++ b/drivers/i2c/fsl_i2c.c @@ -42,6 +42,14 @@ #define CONFIG_I2C_TIMEOUT 10000 #endif +/* + * tWR is the write cycle time for EEPROM device + * in microseconds + */ +#ifndef CONFIG_I2C_TWR +#define CONFIG_I2C_TWR 5000 +#endif + #define I2C_READ_BIT 1 #define I2C_WRITE_BIT 0 @@ -416,6 +424,7 @@ i2c_write(u8 dev, uint addr, int alen, u8 *data, int length) if (i2c_wait4bus()) /* Wait until STOP */ debug("i2c_write: wait4bus timed out\n"); + udelay(CONFIG_I2C_TWR); if (i == length) return 0;