diff options
Diffstat (limited to 'drivers/pwm/pwm-cros-ec.c')
| -rw-r--r-- | drivers/pwm/pwm-cros-ec.c | 37 |
1 files changed, 17 insertions, 20 deletions
diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c index 09c08dee099e..c1c337969e4e 100644 --- a/drivers/pwm/pwm-cros-ec.c +++ b/drivers/pwm/pwm-cros-ec.c @@ -81,8 +81,7 @@ static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty) return cros_ec_cmd_xfer_status(ec, msg); } -static int __cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index, - u32 *result) +static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index) { struct { struct cros_ec_command msg; @@ -107,19 +106,12 @@ static int __cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index, params->index = index; ret = cros_ec_cmd_xfer_status(ec, msg); - if (result) - *result = msg->result; if (ret < 0) return ret; return resp->duty; } -static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index) -{ - return __cros_ec_pwm_get_duty(ec, index, NULL); -} - static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { @@ -204,29 +196,34 @@ 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; /* The index field is only 8 bits */ for (i = 0; i <= U8_MAX; i++) { - 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; - + ret = cros_ec_pwm_get_duty(ec, i); /* * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM * responses; everything else is treated as an error. + * The EC error codes map to -EOPNOTSUPP and -EINVAL, + * so check for those. */ - 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) - return -EPROTO; + default: + if (ret < 0) + return ret; + break; + } } return U8_MAX; |