| Message ID | 20200806153308.204605-5-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | platform/chrome: cros_ec_proto: Convert EC error codes to Linux error codes | expand |
Hello, On Thu, Aug 06, 2020 at 08:33:05AM -0700, Guenter Roeck wrote: > Since commit c5cd2b47b203 ("platform/chrome: cros_ec_proto: Report command > not supported") we can no longer assume that cros_ec_cmd_xfer_status() > reports -EPROTO for all errors returned by the EC itself. A follow-up > patch will change cros_ec_cmd_xfer_status() to report additional errors > reported by the EC as distinguished Linux error codes. > > Handle this change by no longer assuming that only -EPROTO is used > to report all errors returned by the EC itself. Instead, support both > the old and the new error codes. > > Add a comment describing cros_ec_num_pwms() to explain its functionality. > > Cc: Gwendal Grignou <gwendal@chromium.org> > Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org> > Cc: Prashant Malani <pmalani@chromium.org> > Cc: Brian Norris <briannorris@chromium.org> > Acked-by: Thierry Reding <thierry.reding@gmail.com> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Best regards Uwe
diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c index 09c08dee099e..94d3dff9b0e5 100644 --- a/drivers/pwm/pwm-cros-ec.c +++ b/drivers/pwm/pwm-cros-ec.c @@ -204,6 +204,11 @@ static const struct pwm_ops cros_ec_pwm_ops = { .owner = THIS_MODULE, }; +/* + * Determine the number of supported PWMs. The EC does not return the number + * of PWMs it supports directly, so we have to read the pwm duty cycle for + * subsequent channels until we get an error. + */ static int cros_ec_num_pwms(struct cros_ec_device *ec) { int i, ret; @@ -213,20 +218,30 @@ static int cros_ec_num_pwms(struct cros_ec_device *ec) u32 result = 0; ret = __cros_ec_pwm_get_duty(ec, i, &result); - /* We want to parse EC protocol errors */ - if (ret < 0 && !(ret == -EPROTO && result)) - return ret; - /* * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM * responses; everything else is treated as an error. + * The EC error codes either map to -EOPNOTSUPP / -EINVAL, + * or -EPROTO is returned and the EC error is in the result + * field. Check for both. */ - if (result == EC_RES_INVALID_COMMAND) + switch (ret) { + case -EOPNOTSUPP: /* invalid command */ return -ENODEV; - else if (result == EC_RES_INVALID_PARAM) + case -EINVAL: /* invalid parameter */ return i; - else if (result) + case -EPROTO: + /* Old or new error return code: Handle both */ + if (result == EC_RES_INVALID_COMMAND) + return -ENODEV; + else if (result == EC_RES_INVALID_PARAM) + return i; return -EPROTO; + default: + if (ret < 0) + return ret; + break; + } } return U8_MAX;
Since commit c5cd2b47b203 ("platform/chrome: cros_ec_proto: Report command not supported") we can no longer assume that cros_ec_cmd_xfer_status() reports -EPROTO for all errors returned by the EC itself. A follow-up patch will change cros_ec_cmd_xfer_status() to report additional errors reported by the EC as distinguished Linux error codes. Handle this change by no longer assuming that only -EPROTO is used to report all errors returned by the EC itself. Instead, support both the old and the new error codes. Add a comment describing cros_ec_num_pwms() to explain its functionality. Cc: Gwendal Grignou <gwendal@chromium.org> Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org> Cc: Prashant Malani <pmalani@chromium.org> Cc: Brian Norris <briannorris@chromium.org> Acked-by: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- v4: Added comments describing cros_ec_num_pwms() in more detail Added Thierry's Acked-by: tag v3: Added patch drivers/pwm/pwm-cros-ec.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-)