diff options
Diffstat (limited to 'drivers/pwm/core.c')
| -rw-r--r-- | drivers/pwm/core.c | 68 |
1 files changed, 38 insertions, 30 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index d333e7422f4a..e01147f66e15 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -27,7 +27,10 @@ static DEFINE_MUTEX(pwm_lookup_lock); static LIST_HEAD(pwm_lookup_list); + +/* protects access to pwm_chips, allocated_pwms, and pwm_tree */ static DEFINE_MUTEX(pwm_lock); + static LIST_HEAD(pwm_chips); static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); static RADIX_TREE(pwm_tree, GFP_KERNEL); @@ -37,6 +40,7 @@ static struct pwm_device *pwm_to_device(unsigned int pwm) return radix_tree_lookup(&pwm_tree, pwm); } +/* Called with pwm_lock held */ static int alloc_pwms(unsigned int count) { unsigned int start; @@ -47,9 +51,12 @@ static int alloc_pwms(unsigned int count) if (start + count > MAX_PWMS) return -ENOSPC; + bitmap_set(allocated_pwms, start, count); + return start; } +/* Called with pwm_lock held */ static void free_pwms(struct pwm_chip *chip) { unsigned int i; @@ -108,8 +115,13 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) } if (pwm->chip->ops->get_state) { - pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state); - trace_pwm_get(pwm, &pwm->state); + struct pwm_state state; + + err = pwm->chip->ops->get_state(pwm->chip, pwm, &state); + trace_pwm_get(pwm, &state, err); + + if (!err) + pwm->state = state; if (IS_ENABLED(CONFIG_PWM_DEBUG)) pwm->last = pwm->state; @@ -267,20 +279,21 @@ int pwmchip_add(struct pwm_chip *chip) if (!pwm_ops_check(chip)) return -EINVAL; + chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL); + if (!chip->pwms) + return -ENOMEM; + mutex_lock(&pwm_lock); ret = alloc_pwms(chip->npwm); - if (ret < 0) - goto out; + if (ret < 0) { + mutex_unlock(&pwm_lock); + kfree(chip->pwms); + return ret; + } chip->base = ret; - chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL); - if (!chip->pwms) { - ret = -ENOMEM; - goto out; - } - for (i = 0; i < chip->npwm; i++) { pwm = &chip->pwms[i]; @@ -291,23 +304,16 @@ int pwmchip_add(struct pwm_chip *chip) radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } - bitmap_set(allocated_pwms, chip->base, chip->npwm); - - INIT_LIST_HEAD(&chip->list); list_add(&chip->list, &pwm_chips); - ret = 0; + mutex_unlock(&pwm_lock); if (IS_ENABLED(CONFIG_OF)) of_pwmchip_add(chip); -out: - mutex_unlock(&pwm_lock); - - if (!ret) - pwmchip_sysfs_export(chip); + pwmchip_sysfs_export(chip); - return ret; + return 0; } EXPORT_SYMBOL_GPL(pwmchip_add); @@ -457,8 +463,11 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, * checks. */ - chip->ops->get_state(chip, pwm, &s1); - trace_pwm_get(pwm, &s1); + err = chip->ops->get_state(chip, pwm, &s1); + trace_pwm_get(pwm, &s1, err); + if (err) + /* If that failed there isn't much to debug */ + return; /* * The lowlevel driver either ignored .polarity (which is a bug) or as @@ -514,16 +523,17 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, /* reapply the state that the driver reported being configured. */ err = chip->ops->apply(chip, pwm, &s1); + trace_pwm_apply(pwm, &s1, err); if (err) { *last = s1; dev_err(chip->dev, "failed to reapply current setting\n"); return; } - trace_pwm_apply(pwm, &s1); - - chip->ops->get_state(chip, pwm, last); - trace_pwm_get(pwm, last); + err = chip->ops->get_state(chip, pwm, last); + trace_pwm_get(pwm, last, err); + if (err) + return; /* reapplication of the current state should give an exact match */ if (s1.enabled != last->enabled || @@ -571,11 +581,10 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) return 0; err = chip->ops->apply(chip, pwm, state); + trace_pwm_apply(pwm, state, err); if (err) return err; - trace_pwm_apply(pwm, state); - pwm->state = *state; /* @@ -1179,8 +1188,7 @@ DEFINE_SEQ_ATTRIBUTE(pwm_debugfs); static int __init pwm_debugfs_init(void) { - debugfs_create_file("pwm", S_IFREG | 0444, NULL, NULL, - &pwm_debugfs_fops); + debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops); return 0; } |