On Thursday, July 23, 2020 12:24 AM, Jes Sorensen wrote:
> On 7/9/20 3:27 AM, Roy Im wrote:
> > Adds support for the Dialog DA7280 LRA/ERM Haptic Driver with multiple
> > mode and integrated waveform memory and wideband support.
> > It communicates via an I2C bus to the device.
> >
> > Signed-off-by: Roy Im <roy.im.opensource@xxxxxxxxxxx>
> > ---
> > v16:
> > - Corrected some code and updated description in Kconfig.
> > v15:
> > - Removed some defines and updated some comments.
> > v14:
> > - Updated pwm related code, alignments and comments.
> > v13:
> > - Updated some conditions in pwm function and alignments.
> > v12: No changes.
> > v11:
> > - Updated the pwm related code, comments and typo.
> > v10:
> > - Updated the pwm related function and added some comments.
> > v9:
> > - Removed the header file and put the definitions into the c file.
> > - Updated the pwm code and error logs with %pE
> > v8:
> > - Added changes to support FF_PERIODIC/FF_CUSTOM and FF_CONSTANT.
> > - Updated the dt-related code.
> > - Removed memless related functions.
> > v7:
> > - Added more attributes to handle one value per file.
> > - Replaced and updated the dt-related code and functions called.
> > - Fixed error/functions.
> > v6: No changes.
> > v5: Fixed errors in Kconfig file.
> > v4: Updated code as dt-bindings are changed.
> > v3: No changes.
> > v2: Fixed kbuild error/warning
> >
> >
> > drivers/input/misc/Kconfig | 13 +
> > drivers/input/misc/Makefile | 1 +
> > drivers/input/misc/da7280.c | 1840
> > +++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 1854 insertions(+)
> > create mode 100644 drivers/input/misc/da7280.c
>
> Hi Roy,
>
> Overall the driver looks pretty good now. I did find one issue, see below. If you fix that I am happy to add a Reviewed-by line.
>
> Reviewed-By: Jes Sorensen <Jes.Sorensen@xxxxxxxxx>
Thanks a lot and I will fix as you advised below, then I will add a Reviewed-line in the next patch.
>
> > diff --git a/drivers/input/misc/da7280.c b/drivers/input/misc/da7280.c
> > new file mode 100644 index 0000000..c8c42ac
> > --- /dev/null
> > +++ b/drivers/input/misc/da7280.c
>
> [snip]
>
> > +static int da7280_haptic_set_pwm(struct da7280_haptic *haptics, bool enabled)
> > +{
> > + struct pwm_state state;
> > + u64 period_mag_multi;
> > + int error;
> > +
> > + if (!haptics->gain && enabled) {
> > + dev_err(haptics->dev,
> > + "Please set the gain first for the pwm mode\n");
> > + return -EINVAL;
> > + }
> > +
> > + pwm_get_state(haptics->pwm_dev, &state);
> > + state.enabled = enabled;
> > + if (enabled) {
> > + period_mag_multi = state.period * haptics->gain;
>
> You are multiplying an unsigned int to a u16 and storing it in a u64.
> However, C doesn't promote the types, so you'll end up with an
> unexpected result here. You can fix it by promoting state.period to u64, ie:
>
> period_mage_multi = (u64)state.period * haptics->gain;
>
> See the following example code which demonstrates the problem.
>
> #include <stdio.h>
> #include <stdint.h>
>
> uint64_t foo(unsigned int a, uint16_t b)
> {
> uint64_t tmp = a * b;
> return tmp;
> }
>
> uint64_t bar(unsigned int a, uint16_t b)
> {
> uint64_t tmp = (uint64_t)a * b;
> return tmp;
> }
>
> int main()
> {
> uint64_t val;
> unsigned int a = 0xff00ff00;
> uint16_t b = 0x200;
>
> val = foo(a, b);
> printf("result(%0x, %0x) = %0llx\n", a, b, val);
>
> val = bar(a, b);
> printf("result(%0x, %0x) = %0llx\n", a, b, val);
> }
>
> Cheers,
> Jes
Yes, you are right, I see the different result, I will fix this.
Kind regards,
Roy
