From: Guenter Roeck <linux@roeck-us.net>
To: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: "Jonathan Cameron" <jic23@kernel.org>,
"Benson Leung" <bleung@chromium.org>,
"Dmitry Torokhov" <dmitry.torokhov@gmail.com>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Lee Jones" <lee.jones@linaro.org>,
"Gwendal Grignou" <gwendal@chromium.org>,
"Brian Norris" <briannorris@chromium.org>,
"Yu-Hsuan Hsu" <yuhsuan@chromium.org>,
"Prashant Malani" <pmalani@chromium.org>,
linux-iio@vger.kernel.org, linux-input@vger.kernel.org,
linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org,
"Guenter Roeck" <linux@roeck-us.net>
Subject: [PATCH v4 4/7] pwm: cros-ec: Accept more error codes from cros_ec_cmd_xfer_status
Date: Thu, 6 Aug 2020 08:33:05 -0700 [thread overview]
Message-ID: <20200806153308.204605-5-linux@roeck-us.net> (raw)
In-Reply-To: <20200806153308.204605-1-linux@roeck-us.net>
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(-)
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;
--
2.17.1
next prev parent reply other threads:[~2020-08-06 16:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-06 15:33 [PATCH v4 0/7] platform/chrome: cros_ec_proto: Convert EC error codes to Linux error codes Guenter Roeck
2020-08-06 15:33 ` [PATCH v4 1/7] iio: cros_ec: Accept -EOPNOTSUPP as 'not supported' error code Guenter Roeck
2020-08-06 15:33 ` [PATCH v4 2/7] cros_ec_lightbar: Accept more error codes from cros_ec_cmd_xfer_status Guenter Roeck
2020-08-06 15:33 ` [PATCH v4 3/7] platform/chrome: cros_ec_sysfs: Report range of error codes from EC Guenter Roeck
2020-08-06 15:33 ` Guenter Roeck [this message]
2020-08-06 18:35 ` [PATCH v4 4/7] pwm: cros-ec: Accept more error codes from cros_ec_cmd_xfer_status Uwe Kleine-König
2020-08-06 15:33 ` [PATCH v4 5/7] platform/input: cros_ec: Replace -ENOTSUPP with -ENOPROTOOPT Guenter Roeck
2020-08-06 15:33 ` [PATCH v4 6/7] platform/chrome: cros_ec_proto: Convert EC error codes to Linux error codes Guenter Roeck
2020-08-06 15:33 ` [PATCH v4 7/7] pwm: cros-ec: Simplify EC error handling Guenter Roeck
2020-08-06 18:34 ` Uwe Kleine-König
2020-08-06 21:33 ` Brian Norris
2020-08-21 8:21 ` [PATCH v4 0/7] platform/chrome: cros_ec_proto: Convert EC error codes to Linux error codes Enric Balletbo i Serra
2020-08-21 15:39 ` Guenter Roeck
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