| Message ID | 20180418123410.72090-2-heikki.krogerus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Apr 18, 2018 at 03:34:09PM +0300, Heikki Krogerus wrote: > If the I2C adapter that the PD controller is attached to > does not support SMBus protocol, the driver needs to handle > block reads separately. The first byte returned in block > read protocol will show the total number of bytes. It needs > to be stripped away. > > This is handled separately in the driver only because right > now we have no way of requesting the used protocol with > regmap-i2c. This is in practice a workaround for what is > really a problem in regmap-i2c. The other option would have > been to register custom regmap, or not use regmap at all, > however, since the solution is very simple, I choose to use > it in this case for convenience. It is easy to remove once > we figure out how to handle this kind of cases in > regmap-i2c. > > Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ > 1 file changed, 35 insertions(+), 7 deletions(-) > > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c > index 8b8406867c02..82f09cd9792d 100644 > --- a/drivers/usb/typec/tps6598x.c > +++ b/drivers/usb/typec/tps6598x.c > @@ -73,6 +73,7 @@ struct tps6598x { > struct device *dev; > struct regmap *regmap; > struct mutex lock; /* device lock */ > + u8 i2c_protocol:1; > > struct typec_port *port; > struct typec_partner *partner; > @@ -80,6 +81,23 @@ struct tps6598x { > struct typec_capability typec_cap; > }; > > +static int > +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) > +{ > + u8 data[len + 1]; > + int ret; > + > + if (!tps->i2c_protocol) > + return regmap_raw_read(tps->regmap, reg, val, len); > + > + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); > + if (ret) > + return ret; > + Sanity check ? if (data[0] != len) return -Esomething; Other than that, Reviewed-by: Guenter Roeck <linux@roeck-us.net> > + memcpy(val, &data[1], len); > + return 0; > +} > + > static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val) > { > return regmap_raw_read(tps->regmap, reg, val, sizeof(u16)); > @@ -87,12 +105,12 @@ static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val) > > static inline int tps6598x_read32(struct tps6598x *tps, u8 reg, u32 *val) > { > - return regmap_raw_read(tps->regmap, reg, val, sizeof(u32)); > + return tps6598x_block_read(tps, reg, val, sizeof(u32)); > } > > static inline int tps6598x_read64(struct tps6598x *tps, u8 reg, u64 *val) > { > - return regmap_raw_read(tps->regmap, reg, val, sizeof(u64)); > + return tps6598x_block_read(tps, reg, val, sizeof(u64)); > } > > static inline int tps6598x_write16(struct tps6598x *tps, u8 reg, u16 val) > @@ -121,8 +139,8 @@ static int tps6598x_read_partner_identity(struct tps6598x *tps) > struct tps6598x_rx_identity_reg id; > int ret; > > - ret = regmap_raw_read(tps->regmap, TPS_REG_RX_IDENTITY_SOP, > - &id, sizeof(id)); > + ret = tps6598x_block_read(tps, TPS_REG_RX_IDENTITY_SOP, > + &id, sizeof(id)); > if (ret) > return ret; > > @@ -224,13 +242,13 @@ static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd, > } while (val); > > if (out_len) { > - ret = regmap_raw_read(tps->regmap, TPS_REG_DATA1, > - out_data, out_len); > + ret = tps6598x_block_read(tps, TPS_REG_DATA1, > + out_data, out_len); > if (ret) > return ret; > val = out_data[0]; > } else { > - ret = regmap_read(tps->regmap, TPS_REG_DATA1, &val); > + ret = tps6598x_block_read(tps, TPS_REG_DATA1, &val, sizeof(u8)); > if (ret) > return ret; > } > @@ -385,6 +403,16 @@ static int tps6598x_probe(struct i2c_client *client) > if (!vid) > return -ENODEV; > > + /* > + * Checking can the adapter handle SMBus protocol. If if can not, the > + * driver needs to take care of block reads separately. > + * > + * FIXME: Testing with I2C_FUNC_I2C. regmap-i2c uses I2C protocol > + * unconditionally if the adapter has I2C_FUNC_I2C set. > + */ > + if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) > + tps->i2c_protocol = true; > + > ret = tps6598x_read32(tps, TPS_REG_STATUS, &status); > if (ret < 0) > return ret; > -- > 2.17.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Apr 20, 2018 at 10:26:08AM -0700, Guenter Roeck wrote: > On Wed, Apr 18, 2018 at 03:34:09PM +0300, Heikki Krogerus wrote: > > If the I2C adapter that the PD controller is attached to > > does not support SMBus protocol, the driver needs to handle > > block reads separately. The first byte returned in block > > read protocol will show the total number of bytes. It needs > > to be stripped away. > > > > This is handled separately in the driver only because right > > now we have no way of requesting the used protocol with > > regmap-i2c. This is in practice a workaround for what is > > really a problem in regmap-i2c. The other option would have > > been to register custom regmap, or not use regmap at all, > > however, since the solution is very simple, I choose to use > > it in this case for convenience. It is easy to remove once > > we figure out how to handle this kind of cases in > > regmap-i2c. > > > > Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > > --- > > drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ > > 1 file changed, 35 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c > > index 8b8406867c02..82f09cd9792d 100644 > > --- a/drivers/usb/typec/tps6598x.c > > +++ b/drivers/usb/typec/tps6598x.c > > @@ -73,6 +73,7 @@ struct tps6598x { > > struct device *dev; > > struct regmap *regmap; > > struct mutex lock; /* device lock */ > > + u8 i2c_protocol:1; > > > > struct typec_port *port; > > struct typec_partner *partner; > > @@ -80,6 +81,23 @@ struct tps6598x { > > struct typec_capability typec_cap; > > }; > > > > +static int > > +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) > > +{ > > + u8 data[len + 1]; > > + int ret; > > + > > + if (!tps->i2c_protocol) > > + return regmap_raw_read(tps->regmap, reg, val, len); > > + > > + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); > > + if (ret) > > + return ret; > > + > > Sanity check ? > if (data[0] != len) > return -Esomething; > > Other than that, > > Reviewed-by: Guenter Roeck <linux@roeck-us.net> I'll wait for a v2 of this to apply it. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Apr 20, 2018 at 10:26:08AM -0700, Guenter Roeck wrote: > On Wed, Apr 18, 2018 at 03:34:09PM +0300, Heikki Krogerus wrote: > > If the I2C adapter that the PD controller is attached to > > does not support SMBus protocol, the driver needs to handle > > block reads separately. The first byte returned in block > > read protocol will show the total number of bytes. It needs > > to be stripped away. > > > > This is handled separately in the driver only because right > > now we have no way of requesting the used protocol with > > regmap-i2c. This is in practice a workaround for what is > > really a problem in regmap-i2c. The other option would have > > been to register custom regmap, or not use regmap at all, > > however, since the solution is very simple, I choose to use > > it in this case for convenience. It is easy to remove once > > we figure out how to handle this kind of cases in > > regmap-i2c. > > > > Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > > --- > > drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ > > 1 file changed, 35 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c > > index 8b8406867c02..82f09cd9792d 100644 > > --- a/drivers/usb/typec/tps6598x.c > > +++ b/drivers/usb/typec/tps6598x.c > > @@ -73,6 +73,7 @@ struct tps6598x { > > struct device *dev; > > struct regmap *regmap; > > struct mutex lock; /* device lock */ > > + u8 i2c_protocol:1; > > > > struct typec_port *port; > > struct typec_partner *partner; > > @@ -80,6 +81,23 @@ struct tps6598x { > > struct typec_capability typec_cap; > > }; > > > > +static int > > +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) > > +{ > > + u8 data[len + 1]; > > + int ret; > > + > > + if (!tps->i2c_protocol) > > + return regmap_raw_read(tps->regmap, reg, val, len); > > + > > + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); > > + if (ret) > > + return ret; > > + > > Sanity check ? > if (data[0] != len) > return -Esomething; No. Then we would not even need the len parameter. The idea is to allow reading a number of bytes specified by caller, regardless of the maximum size of the block. Thanks,
On Mon, Apr 23, 2018 at 11:03:09AM +0300, Heikki Krogerus wrote: > On Fri, Apr 20, 2018 at 10:26:08AM -0700, Guenter Roeck wrote: > > On Wed, Apr 18, 2018 at 03:34:09PM +0300, Heikki Krogerus wrote: > > > If the I2C adapter that the PD controller is attached to > > > does not support SMBus protocol, the driver needs to handle > > > block reads separately. The first byte returned in block > > > read protocol will show the total number of bytes. It needs > > > to be stripped away. > > > > > > This is handled separately in the driver only because right > > > now we have no way of requesting the used protocol with > > > regmap-i2c. This is in practice a workaround for what is > > > really a problem in regmap-i2c. The other option would have > > > been to register custom regmap, or not use regmap at all, > > > however, since the solution is very simple, I choose to use > > > it in this case for convenience. It is easy to remove once > > > we figure out how to handle this kind of cases in > > > regmap-i2c. > > > > > > Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") > > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > > > --- > > > drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ > > > 1 file changed, 35 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c > > > index 8b8406867c02..82f09cd9792d 100644 > > > --- a/drivers/usb/typec/tps6598x.c > > > +++ b/drivers/usb/typec/tps6598x.c > > > @@ -73,6 +73,7 @@ struct tps6598x { > > > struct device *dev; > > > struct regmap *regmap; > > > struct mutex lock; /* device lock */ > > > + u8 i2c_protocol:1; > > > > > > struct typec_port *port; > > > struct typec_partner *partner; > > > @@ -80,6 +81,23 @@ struct tps6598x { > > > struct typec_capability typec_cap; > > > }; > > > > > > +static int > > > +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) > > > +{ > > > + u8 data[len + 1]; > > > + int ret; > > > + > > > + if (!tps->i2c_protocol) > > > + return regmap_raw_read(tps->regmap, reg, val, len); > > > + > > > + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); > > > + if (ret) > > > + return ret; > > > + > > > > Sanity check ? > > if (data[0] != len) > > return -Esomething; > > No. Then we would not even need the len parameter. The idea is to > allow reading a number of bytes specified by caller, regardless of the > maximum size of the block. > If I2C_FUNC_I2C is not supported but I2C_FUNC_SMBUS_I2C_BLOCK is, the regmap core will use i2c_smbus_read_i2c_block_data() and validate the return length. It will return -EIO if it does not match. That seems inconsistent. Also, I am not sure how you know that at least the minimum required number of bytes is returned if the number of bytes requested is larger than the number of bytes returned by the chip. Am I missing something ? Also, I notice that your patch does not touch tps6598x_read16(). Yet, according to "TPS65981, TPS65982, and TPS65986 Host Interface Technical Reference Manual", it appears that the 2-byte command used (0x3f) does support/use block commands. Is that an oversight or on purpose ? Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Apr 23, 2018 at 09:43:57AM -0700, Guenter Roeck wrote: > On Mon, Apr 23, 2018 at 11:03:09AM +0300, Heikki Krogerus wrote: > > On Fri, Apr 20, 2018 at 10:26:08AM -0700, Guenter Roeck wrote: > > > On Wed, Apr 18, 2018 at 03:34:09PM +0300, Heikki Krogerus wrote: > > > > If the I2C adapter that the PD controller is attached to > > > > does not support SMBus protocol, the driver needs to handle > > > > block reads separately. The first byte returned in block > > > > read protocol will show the total number of bytes. It needs > > > > to be stripped away. > > > > > > > > This is handled separately in the driver only because right > > > > now we have no way of requesting the used protocol with > > > > regmap-i2c. This is in practice a workaround for what is > > > > really a problem in regmap-i2c. The other option would have > > > > been to register custom regmap, or not use regmap at all, > > > > however, since the solution is very simple, I choose to use > > > > it in this case for convenience. It is easy to remove once > > > > we figure out how to handle this kind of cases in > > > > regmap-i2c. > > > > > > > > Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") > > > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > > > > --- > > > > drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ > > > > 1 file changed, 35 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c > > > > index 8b8406867c02..82f09cd9792d 100644 > > > > --- a/drivers/usb/typec/tps6598x.c > > > > +++ b/drivers/usb/typec/tps6598x.c > > > > @@ -73,6 +73,7 @@ struct tps6598x { > > > > struct device *dev; > > > > struct regmap *regmap; > > > > struct mutex lock; /* device lock */ > > > > + u8 i2c_protocol:1; > > > > > > > > struct typec_port *port; > > > > struct typec_partner *partner; > > > > @@ -80,6 +81,23 @@ struct tps6598x { > > > > struct typec_capability typec_cap; > > > > }; > > > > > > > > +static int > > > > +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) > > > > +{ > > > > + u8 data[len + 1]; > > > > + int ret; > > > > + > > > > + if (!tps->i2c_protocol) > > > > + return regmap_raw_read(tps->regmap, reg, val, len); > > > > + > > > > + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); > > > > + if (ret) > > > > + return ret; > > > > + > > > > > > Sanity check ? > > > if (data[0] != len) > > > return -Esomething; > > > > No. Then we would not even need the len parameter. The idea is to > > allow reading a number of bytes specified by caller, regardless of the > > maximum size of the block. > > > If I2C_FUNC_I2C is not supported but I2C_FUNC_SMBUS_I2C_BLOCK is, the > regmap core will use i2c_smbus_read_i2c_block_data() and validate the > return length. It will return -EIO if it does not match. That seems > inconsistent. For some reason I though that regmap-i2c supports I2C_FUNC_SMBUS_BLOCK_DATA functionality instead of I2C_FUNC_SMBUS_I2C_BLOCK_DATA. I stand corrected. > Also, I am not sure how you know that at least the minimum > required number of bytes is returned if the number of bytes requested > is larger than the number of bytes returned by the chip. Am I missing > something ? If the slave chip returns less bytes then what we are asking from it, the adapter driver should return an error, timeout most likely, no? Or did I misunderstood the question? In any case, I will add some sanity checks. I just wanted to make sure we don't add useless checks. > Also, I notice that your patch does not touch tps6598x_read16(). Yet, > according to "TPS65981, TPS65982, and TPS65986 Host Interface Technical > Reference Manual", it appears that the 2-byte command used (0x3f) does > support/use block commands. Is that an oversight or on purpose ? I did not change it because in my test I did not see the byte count in the first byte, but I'm questioning myself now... I need to re-check it. I may have done that test with wrong platform. Thanks Guenter,
On 04/24/2018 04:46 AM, Heikki Krogerus wrote: > On Mon, Apr 23, 2018 at 09:43:57AM -0700, Guenter Roeck wrote: >> On Mon, Apr 23, 2018 at 11:03:09AM +0300, Heikki Krogerus wrote: >>> On Fri, Apr 20, 2018 at 10:26:08AM -0700, Guenter Roeck wrote: >>>> On Wed, Apr 18, 2018 at 03:34:09PM +0300, Heikki Krogerus wrote: >>>>> If the I2C adapter that the PD controller is attached to >>>>> does not support SMBus protocol, the driver needs to handle >>>>> block reads separately. The first byte returned in block >>>>> read protocol will show the total number of bytes. It needs >>>>> to be stripped away. >>>>> >>>>> This is handled separately in the driver only because right >>>>> now we have no way of requesting the used protocol with >>>>> regmap-i2c. This is in practice a workaround for what is >>>>> really a problem in regmap-i2c. The other option would have >>>>> been to register custom regmap, or not use regmap at all, >>>>> however, since the solution is very simple, I choose to use >>>>> it in this case for convenience. It is easy to remove once >>>>> we figure out how to handle this kind of cases in >>>>> regmap-i2c. >>>>> >>>>> Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") >>>>> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> >>>>> --- >>>>> drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ >>>>> 1 file changed, 35 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c >>>>> index 8b8406867c02..82f09cd9792d 100644 >>>>> --- a/drivers/usb/typec/tps6598x.c >>>>> +++ b/drivers/usb/typec/tps6598x.c >>>>> @@ -73,6 +73,7 @@ struct tps6598x { >>>>> struct device *dev; >>>>> struct regmap *regmap; >>>>> struct mutex lock; /* device lock */ >>>>> + u8 i2c_protocol:1; >>>>> >>>>> struct typec_port *port; >>>>> struct typec_partner *partner; >>>>> @@ -80,6 +81,23 @@ struct tps6598x { >>>>> struct typec_capability typec_cap; >>>>> }; >>>>> >>>>> +static int >>>>> +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) >>>>> +{ >>>>> + u8 data[len + 1]; >>>>> + int ret; >>>>> + >>>>> + if (!tps->i2c_protocol) >>>>> + return regmap_raw_read(tps->regmap, reg, val, len); >>>>> + >>>>> + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); >>>>> + if (ret) >>>>> + return ret; >>>>> + >>>> >>>> Sanity check ? >>>> if (data[0] != len) >>>> return -Esomething; >>> >>> No. Then we would not even need the len parameter. The idea is to >>> allow reading a number of bytes specified by caller, regardless of the >>> maximum size of the block. >>> >> If I2C_FUNC_I2C is not supported but I2C_FUNC_SMBUS_I2C_BLOCK is, the >> regmap core will use i2c_smbus_read_i2c_block_data() and validate the >> return length. It will return -EIO if it does not match. That seems >> inconsistent. > > For some reason I though that regmap-i2c supports > I2C_FUNC_SMBUS_BLOCK_DATA functionality instead of > I2C_FUNC_SMBUS_I2C_BLOCK_DATA. I stand corrected. > >> Also, I am not sure how you know that at least the minimum >> required number of bytes is returned if the number of bytes requested >> is larger than the number of bytes returned by the chip. Am I missing >> something ? > > If the slave chip returns less bytes then what we are asking from it, > the adapter driver should return an error, timeout most likely, no? Or > did I misunderstood the question? > The chip should return the number of bytes it has available and then NAK the transfer. The chip driver should then report the number of bytes read to its caller. This is why i2c_smbus_read_block_data() and friends return not just 0/-errno, but the number of bytes read. Guenter > In any case, I will add some sanity checks. I just wanted to make sure > we don't add useless checks. > >> Also, I notice that your patch does not touch tps6598x_read16(). Yet, >> according to "TPS65981, TPS65982, and TPS65986 Host Interface Technical >> Reference Manual", it appears that the 2-byte command used (0x3f) does >> support/use block commands. Is that an oversight or on purpose ? > > I did not change it because in my test I did not see the byte count in > the first byte, but I'm questioning myself now... I need to re-check > it. I may have done that test with wrong platform. > > > Thanks Guenter, > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Apr 24, 2018 at 06:02:56AM -0700, Guenter Roeck wrote: > The chip should return the number of bytes it has available and then NAK > the transfer. The chip driver should then report the number of bytes read > to its caller. This is why i2c_smbus_read_block_data() and friends return > not just 0/-errno, but the number of bytes read. Thanks for the info. Br,
diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c index 8b8406867c02..82f09cd9792d 100644 --- a/drivers/usb/typec/tps6598x.c +++ b/drivers/usb/typec/tps6598x.c @@ -73,6 +73,7 @@ struct tps6598x { struct device *dev; struct regmap *regmap; struct mutex lock; /* device lock */ + u8 i2c_protocol:1; struct typec_port *port; struct typec_partner *partner; @@ -80,6 +81,23 @@ struct tps6598x { struct typec_capability typec_cap; }; +static int +tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, ssize_t len) +{ + u8 data[len + 1]; + int ret; + + if (!tps->i2c_protocol) + return regmap_raw_read(tps->regmap, reg, val, len); + + ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data)); + if (ret) + return ret; + + memcpy(val, &data[1], len); + return 0; +} + static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val) { return regmap_raw_read(tps->regmap, reg, val, sizeof(u16)); @@ -87,12 +105,12 @@ static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val) static inline int tps6598x_read32(struct tps6598x *tps, u8 reg, u32 *val) { - return regmap_raw_read(tps->regmap, reg, val, sizeof(u32)); + return tps6598x_block_read(tps, reg, val, sizeof(u32)); } static inline int tps6598x_read64(struct tps6598x *tps, u8 reg, u64 *val) { - return regmap_raw_read(tps->regmap, reg, val, sizeof(u64)); + return tps6598x_block_read(tps, reg, val, sizeof(u64)); } static inline int tps6598x_write16(struct tps6598x *tps, u8 reg, u16 val) @@ -121,8 +139,8 @@ static int tps6598x_read_partner_identity(struct tps6598x *tps) struct tps6598x_rx_identity_reg id; int ret; - ret = regmap_raw_read(tps->regmap, TPS_REG_RX_IDENTITY_SOP, - &id, sizeof(id)); + ret = tps6598x_block_read(tps, TPS_REG_RX_IDENTITY_SOP, + &id, sizeof(id)); if (ret) return ret; @@ -224,13 +242,13 @@ static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd, } while (val); if (out_len) { - ret = regmap_raw_read(tps->regmap, TPS_REG_DATA1, - out_data, out_len); + ret = tps6598x_block_read(tps, TPS_REG_DATA1, + out_data, out_len); if (ret) return ret; val = out_data[0]; } else { - ret = regmap_read(tps->regmap, TPS_REG_DATA1, &val); + ret = tps6598x_block_read(tps, TPS_REG_DATA1, &val, sizeof(u8)); if (ret) return ret; } @@ -385,6 +403,16 @@ static int tps6598x_probe(struct i2c_client *client) if (!vid) return -ENODEV; + /* + * Checking can the adapter handle SMBus protocol. If if can not, the + * driver needs to take care of block reads separately. + * + * FIXME: Testing with I2C_FUNC_I2C. regmap-i2c uses I2C protocol + * unconditionally if the adapter has I2C_FUNC_I2C set. + */ + if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + tps->i2c_protocol = true; + ret = tps6598x_read32(tps, TPS_REG_STATUS, &status); if (ret < 0) return ret;
If the I2C adapter that the PD controller is attached to does not support SMBus protocol, the driver needs to handle block reads separately. The first byte returned in block read protocol will show the total number of bytes. It needs to be stripped away. This is handled separately in the driver only because right now we have no way of requesting the used protocol with regmap-i2c. This is in practice a workaround for what is really a problem in regmap-i2c. The other option would have been to register custom regmap, or not use regmap at all, however, since the solution is very simple, I choose to use it in this case for convenience. It is easy to remove once we figure out how to handle this kind of cases in regmap-i2c. Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers") Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> --- drivers/usb/typec/tps6598x.c | 42 ++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 7 deletions(-)