* [PATCH 0/2] ad5593r fix read protocol
@ 2022-09-13 7:34 Nuno Sá
2022-09-13 7:34 ` [PATCH 1/2] iio: dac: ad5593r: Fix i2c read protocol requirements Nuno Sá
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Nuno Sá @ 2022-09-13 7:34 UTC (permalink / raw)
To: linux-iio; +Cc: Michael Hennerich, Lars-Peter Clausen, Jonathan Cameron
This patchset fixes the read protocol since it needs a STOP condition
between address write and data read.
The second change is trivial and only adds an i2c functionality check.
Michael Hennerich (1):
iio: dac: ad5593r: Fix i2c read protocol requirements
Nuno Sá (1):
iio: dac: ad5593r: add check for i2c functionality
drivers/iio/dac/ad5593r.c | 48 +++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 20 deletions(-)
--
2.37.3
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] iio: dac: ad5593r: Fix i2c read protocol requirements
2022-09-13 7:34 [PATCH 0/2] ad5593r fix read protocol Nuno Sá
@ 2022-09-13 7:34 ` Nuno Sá
2022-09-13 7:34 ` [PATCH 2/2] iio: dac: ad5593r: add check for i2c functionality Nuno Sá
2022-09-15 14:38 ` [PATCH 0/2] ad5593r fix read protocol Jonathan Cameron
2 siblings, 0 replies; 6+ messages in thread
From: Nuno Sá @ 2022-09-13 7:34 UTC (permalink / raw)
To: linux-iio
Cc: Michael Hennerich, Lars-Peter Clausen, Jonathan Cameron,
Michael Hennerich
From: Michael Hennerich <michael.hennerich@analog.com>
For reliable operation across the full range of supported
interface rates, the AD5593R needs a STOP condition between
address write, and data read (like show in the datasheet Figure 40)
so in turn i2c_smbus_read_word_swapped cannot be used.
While at it, a simple helper was added to make the code simpler.
Fixes: 56ca9db862bf ("iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs")
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
drivers/iio/dac/ad5593r.c | 44 +++++++++++++++++++++------------------
1 file changed, 24 insertions(+), 20 deletions(-)
diff --git a/drivers/iio/dac/ad5593r.c b/drivers/iio/dac/ad5593r.c
index 34e1319a9712..43ee4efb250c 100644
--- a/drivers/iio/dac/ad5593r.c
+++ b/drivers/iio/dac/ad5593r.c
@@ -20,6 +20,24 @@
#define AD5593R_MODE_GPIO_READBACK (6 << 4)
#define AD5593R_MODE_REG_READBACK (7 << 4)
+static int ad5593r_read_word(struct i2c_client *i2c, u8 reg, u16 *value)
+{
+ int ret;
+ u8 buf[2];
+
+ ret = i2c_smbus_write_byte(i2c, reg);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_master_recv(i2c, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ *value = get_unaligned_be16(buf);
+
+ return 0;
+}
+
static int ad5593r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
{
struct i2c_client *i2c = to_i2c_client(st->dev);
@@ -38,13 +56,7 @@ static int ad5593r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
if (val < 0)
return (int) val;
- val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK);
- if (val < 0)
- return (int) val;
-
- *value = (u16) val;
-
- return 0;
+ return ad5593r_read_word(i2c, AD5593R_MODE_ADC_READBACK, value);
}
static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
@@ -58,29 +70,21 @@ static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
{
struct i2c_client *i2c = to_i2c_client(st->dev);
- s32 val;
-
- val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_REG_READBACK | reg);
- if (val < 0)
- return (int) val;
-
- *value = (u16) val;
- return 0;
+ return ad5593r_read_word(i2c, AD5593R_MODE_REG_READBACK | reg, value);
}
static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value)
{
struct i2c_client *i2c = to_i2c_client(st->dev);
- s32 val;
+ u16 val;
+ int ret;
- val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_GPIO_READBACK);
- if (val < 0)
- return (int) val;
+ ret = ad5593r_read_word(i2c, AD5593R_MODE_GPIO_READBACK, &val);
*value = (u8) val;
- return 0;
+ return ret;
}
static const struct ad5592r_rw_ops ad5593r_rw_ops = {
--
2.37.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] iio: dac: ad5593r: add check for i2c functionality
2022-09-13 7:34 [PATCH 0/2] ad5593r fix read protocol Nuno Sá
2022-09-13 7:34 ` [PATCH 1/2] iio: dac: ad5593r: Fix i2c read protocol requirements Nuno Sá
@ 2022-09-13 7:34 ` Nuno Sá
2022-09-15 14:38 ` [PATCH 0/2] ad5593r fix read protocol Jonathan Cameron
2 siblings, 0 replies; 6+ messages in thread
From: Nuno Sá @ 2022-09-13 7:34 UTC (permalink / raw)
To: linux-iio
Cc: Michael Hennerich, Lars-Peter Clausen, Jonathan Cameron,
Michael Hennerich
Make sure that the needed i2c functionality is supported during probe.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
---
drivers/iio/dac/ad5593r.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/iio/dac/ad5593r.c b/drivers/iio/dac/ad5593r.c
index 43ee4efb250c..f09433e298db 100644
--- a/drivers/iio/dac/ad5593r.c
+++ b/drivers/iio/dac/ad5593r.c
@@ -98,6 +98,10 @@ static const struct ad5592r_rw_ops ad5593r_rw_ops = {
static int ad5593r_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
+ if (!i2c_check_functionality(i2c->adapter,
+ I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
+ return -EOPNOTSUPP;
+
return ad5592r_probe(&i2c->dev, id->name, &ad5593r_rw_ops);
}
--
2.37.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2] ad5593r fix read protocol
2022-09-13 7:34 [PATCH 0/2] ad5593r fix read protocol Nuno Sá
2022-09-13 7:34 ` [PATCH 1/2] iio: dac: ad5593r: Fix i2c read protocol requirements Nuno Sá
2022-09-13 7:34 ` [PATCH 2/2] iio: dac: ad5593r: add check for i2c functionality Nuno Sá
@ 2022-09-15 14:38 ` Jonathan Cameron
2022-09-16 6:05 ` Nuno Sá
2 siblings, 1 reply; 6+ messages in thread
From: Jonathan Cameron @ 2022-09-15 14:38 UTC (permalink / raw)
To: Nuno Sá; +Cc: linux-iio, Michael Hennerich, Lars-Peter Clausen
On Tue, 13 Sep 2022 09:34:11 +0200
Nuno Sá <nuno.sa@analog.com> wrote:
> This patchset fixes the read protocol since it needs a STOP condition
> between address write and data read.
>
> The second change is trivial and only adds an i2c functionality check.
Given we are late in the cycle, I've queued this up for the next merge
window, with a stable tag for the first paatch so it'll get backported
after the merge window.
Thanks,
Jonathan
>
> Michael Hennerich (1):
> iio: dac: ad5593r: Fix i2c read protocol requirements
>
> Nuno Sá (1):
> iio: dac: ad5593r: add check for i2c functionality
>
> drivers/iio/dac/ad5593r.c | 48 +++++++++++++++++++++++----------------
> 1 file changed, 28 insertions(+), 20 deletions(-)
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2] ad5593r fix read protocol
2022-09-15 14:38 ` [PATCH 0/2] ad5593r fix read protocol Jonathan Cameron
@ 2022-09-16 6:05 ` Nuno Sá
2022-09-16 15:30 ` Jonathan Cameron
0 siblings, 1 reply; 6+ messages in thread
From: Nuno Sá @ 2022-09-16 6:05 UTC (permalink / raw)
To: Jonathan Cameron, Nuno Sá
Cc: linux-iio, Michael Hennerich, Lars-Peter Clausen
On Thu, 2022-09-15 at 15:38 +0100, Jonathan Cameron wrote:
> On Tue, 13 Sep 2022 09:34:11 +0200
> Nuno Sá <nuno.sa@analog.com> wrote:
>
> > This patchset fixes the read protocol since it needs a STOP
> > condition
> > between address write and data read.
> >
> > The second change is trivial and only adds an i2c functionality
> > check.
>
> Given we are late in the cycle, I've queued this up for the next
> merge
> window, with a stable tag for the first paatch so it'll get
> backported
> after the merge window.
>
>
Alright. BTW, not sure If I already asked this but do you have any
preference with regards to CCing stable? Should I have done it when
submitting or do you prefer to handle it yourself?
- Nuno Sá
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2] ad5593r fix read protocol
2022-09-16 6:05 ` Nuno Sá
@ 2022-09-16 15:30 ` Jonathan Cameron
0 siblings, 0 replies; 6+ messages in thread
From: Jonathan Cameron @ 2022-09-16 15:30 UTC (permalink / raw)
To: Nuno Sá
Cc: Jonathan Cameron, Nuno Sá,
linux-iio, Michael Hennerich, Lars-Peter Clausen
On Fri, 16 Sep 2022 08:05:29 +0200
Nuno Sá <noname.nuno@gmail.com> wrote:
> On Thu, 2022-09-15 at 15:38 +0100, Jonathan Cameron wrote:
> > On Tue, 13 Sep 2022 09:34:11 +0200
> > Nuno Sá <nuno.sa@analog.com> wrote:
> >
> > > This patchset fixes the read protocol since it needs a STOP
> > > condition
> > > between address write and data read.
> > >
> > > The second change is trivial and only adds an i2c functionality
> > > check.
> >
> > Given we are late in the cycle, I've queued this up for the next
> > merge
> > window, with a stable tag for the first paatch so it'll get
> > backported
> > after the merge window.
> >
> >
>
> Alright. BTW, not sure If I already asked this but do you have any
> preference with regards to CCing stable? Should I have done it when
> submitting or do you prefer to handle it yourself?
Generally I prefer submitters to not tag for stable and let me make that
decision. Often I'll decide to not tag because I'm a little worried
about a fix and want it to be in mainline a little while before we
backport. I don't mind people sending explicit backport requests
though once it's soaked a bit.
Mind you, these days the scripts that check for possible fixes
often pick these up before I've gotten to sending a backport
request. Sometimes I send a note when that happens to ask for
it to soak longer, but mostly the delay is enough that I'm happy
the patch got enough soaking before that happens.
Occasionally I just forget to tag with stable. If that happens
then I'm fine with a request to pick it up being sent out once
it is upstream!
Jonathan
>
> - Nuno Sá
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-09-16 15:30 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2022-09-13 7:34 [PATCH 0/2] ad5593r fix read protocol Nuno Sá
2022-09-13 7:34 ` [PATCH 1/2] iio: dac: ad5593r: Fix i2c read protocol requirements Nuno Sá
2022-09-13 7:34 ` [PATCH 2/2] iio: dac: ad5593r: add check for i2c functionality Nuno Sá
2022-09-15 14:38 ` [PATCH 0/2] ad5593r fix read protocol Jonathan Cameron
2022-09-16 6:05 ` Nuno Sá
2022-09-16 15:30 ` Jonathan Cameron
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