pwm: cros-ec: Accept more error codes from cros_ec_cmd_xfer_status (d509f8a7) · Commits · 戴 / test

Since commit ("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> Acked-by:

Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:

Guenter Roeck <linux@roeck-us.net> Signed-off-by:

Enric Balletbo i Serra <enric.balletbo@collabora.com>

drivers/pwm/pwm-cros-ec.c

+22 −7

Original line number	Diff line number	Diff line
		@@ -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.
		*/
		switch (ret) {
		case -EOPNOTSUPP: /* invalid command */
		return -ENODEV;
		case -EINVAL: /* invalid parameter */
		return i;
		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;
		else if (result)
		return -EPROTO;
		default:
		if (ret < 0)
		return ret;
		break;
		}
		}

		return U8_MAX;

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