summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/sysfs.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-10 11:14:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-10 11:14:56 -0700
commit34ae0a6f05aee9f51fca17001b4a90703d434ae1 (patch)
tree3ccc8bedae647eb37f46e8ff9f39cdcd84a2f2ac /drivers/pwm/sysfs.c
parent7d3107d26b522a0fe92af6279256fa65fe3db771 (diff)
parentb388f15fd14c3ae62deb9a059464aa99b524ea4a (diff)
downloadop-kernel-dev-34ae0a6f05aee9f51fca17001b4a90703d434ae1.zip
op-kernel-dev-34ae0a6f05aee9f51fca17001b4a90703d434ae1.tar.gz
Merge tag 'for-3.11-rc1' of git://gitorious.org/linux-pwm/linux-pwm
Pull pwm changes from Thierry Reding: "A new driver supports driving PWM signals using the TPU unit found on various Renesas SoCs. Furthermore support is added for the NXP PCA9685 LED controller. Another big chunk is the sysfs interface which has been in the works for quite some time. The remaining patches are a random assortment of cleanups and fixes" * tag 'for-3.11-rc1' of git://gitorious.org/linux-pwm/linux-pwm: pwm: pwm-tiehrpwm: Use clk_enable/disable instead clk_prepare/unprepare. pwm: pca9685: Fix wrong argument to set MODE1_SLEEP bit pwm: renesas-tpu: Add MODULE_ALIAS to make module auto loading work pwm: renesas-tpu: fix return value check in tpu_probe() pwm: Add Renesas TPU PWM driver pwm: Add sysfs interface pwm: Fill in missing .owner fields pwm: add pca9685 driver pwm: atmel-tcb: prepare clk before calling enable pwm: devm: alloc correct pointer size pwm: mxs: Let device core handle pinctrl MAINTAINERS: Update PWM subsystem entry
Diffstat (limited to 'drivers/pwm/sysfs.c')
-rw-r--r--drivers/pwm/sysfs.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
new file mode 100644
index 0000000..8ca5de3
--- /dev/null
+++ b/drivers/pwm/sysfs.c
@@ -0,0 +1,352 @@
+/*
+ * A simple sysfs interface for the generic PWM framework
+ *
+ * Copyright (C) 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *
+ * Based on previous work by Lars Poeschel <poeschel@lemonage.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/kdev_t.h>
+#include <linux/pwm.h>
+
+struct pwm_export {
+ struct device child;
+ struct pwm_device *pwm;
+};
+
+static struct pwm_export *child_to_pwm_export(struct device *child)
+{
+ return container_of(child, struct pwm_export, child);
+}
+
+static struct pwm_device *child_to_pwm_device(struct device *child)
+{
+ struct pwm_export *export = child_to_pwm_export(child);
+
+ return export->pwm;
+}
+
+static ssize_t pwm_period_show(struct device *child,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = child_to_pwm_device(child);
+
+ return sprintf(buf, "%u\n", pwm->period);
+}
+
+static ssize_t pwm_period_store(struct device *child,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_device *pwm = child_to_pwm_device(child);
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ ret = pwm_config(pwm, pwm->duty_cycle, val);
+
+ return ret ? : size;
+}
+
+static ssize_t pwm_duty_cycle_show(struct device *child,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = child_to_pwm_device(child);
+
+ return sprintf(buf, "%u\n", pwm->duty_cycle);
+}
+
+static ssize_t pwm_duty_cycle_store(struct device *child,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_device *pwm = child_to_pwm_device(child);
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ ret = pwm_config(pwm, val, pwm->period);
+
+ return ret ? : size;
+}
+
+static ssize_t pwm_enable_show(struct device *child,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = child_to_pwm_device(child);
+ int enabled = test_bit(PWMF_ENABLED, &pwm->flags);
+
+ return sprintf(buf, "%d\n", enabled);
+}
+
+static ssize_t pwm_enable_store(struct device *child,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_device *pwm = child_to_pwm_device(child);
+ int val, ret;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ switch (val) {
+ case 0:
+ pwm_disable(pwm);
+ break;
+ case 1:
+ ret = pwm_enable(pwm);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret ? : size;
+}
+
+static ssize_t pwm_polarity_show(struct device *child,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = child_to_pwm_device(child);
+
+ return sprintf(buf, "%s\n", pwm->polarity ? "inversed" : "normal");
+}
+
+static ssize_t pwm_polarity_store(struct device *child,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_device *pwm = child_to_pwm_device(child);
+ enum pwm_polarity polarity;
+ int ret;
+
+ if (sysfs_streq(buf, "normal"))
+ polarity = PWM_POLARITY_NORMAL;
+ else if (sysfs_streq(buf, "inversed"))
+ polarity = PWM_POLARITY_INVERSED;
+ else
+ return -EINVAL;
+
+ ret = pwm_set_polarity(pwm, polarity);
+
+ return ret ? : size;
+}
+
+static DEVICE_ATTR(period, 0644, pwm_period_show, pwm_period_store);
+static DEVICE_ATTR(duty_cycle, 0644, pwm_duty_cycle_show, pwm_duty_cycle_store);
+static DEVICE_ATTR(enable, 0644, pwm_enable_show, pwm_enable_store);
+static DEVICE_ATTR(polarity, 0644, pwm_polarity_show, pwm_polarity_store);
+
+static struct attribute *pwm_attrs[] = {
+ &dev_attr_period.attr,
+ &dev_attr_duty_cycle.attr,
+ &dev_attr_enable.attr,
+ &dev_attr_polarity.attr,
+ NULL
+};
+
+static const struct attribute_group pwm_attr_group = {
+ .attrs = pwm_attrs,
+};
+
+static const struct attribute_group *pwm_attr_groups[] = {
+ &pwm_attr_group,
+ NULL,
+};
+
+static void pwm_export_release(struct device *child)
+{
+ struct pwm_export *export = child_to_pwm_export(child);
+
+ kfree(export);
+}
+
+static int pwm_export_child(struct device *parent, struct pwm_device *pwm)
+{
+ struct pwm_export *export;
+ int ret;
+
+ if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
+ return -EBUSY;
+
+ export = kzalloc(sizeof(*export), GFP_KERNEL);
+ if (!export) {
+ clear_bit(PWMF_EXPORTED, &pwm->flags);
+ return -ENOMEM;
+ }
+
+ export->pwm = pwm;
+
+ export->child.release = pwm_export_release;
+ export->child.parent = parent;
+ export->child.devt = MKDEV(0, 0);
+ export->child.groups = pwm_attr_groups;
+ dev_set_name(&export->child, "pwm%u", pwm->hwpwm);
+
+ ret = device_register(&export->child);
+ if (ret) {
+ clear_bit(PWMF_EXPORTED, &pwm->flags);
+ kfree(export);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int pwm_unexport_match(struct device *child, void *data)
+{
+ return child_to_pwm_device(child) == data;
+}
+
+static int pwm_unexport_child(struct device *parent, struct pwm_device *pwm)
+{
+ struct device *child;
+
+ if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
+ return -ENODEV;
+
+ child = device_find_child(parent, pwm, pwm_unexport_match);
+ if (!child)
+ return -ENODEV;
+
+ /* for device_find_child() */
+ put_device(child);
+ device_unregister(child);
+ pwm_put(pwm);
+
+ return 0;
+}
+
+static ssize_t pwm_export_store(struct device *parent,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct pwm_chip *chip = dev_get_drvdata(parent);
+ struct pwm_device *pwm;
+ unsigned int hwpwm;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &hwpwm);
+ if (ret < 0)
+ return ret;
+
+ if (hwpwm >= chip->npwm)
+ return -ENODEV;
+
+ pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
+ if (IS_ERR(pwm))
+ return PTR_ERR(pwm);
+
+ ret = pwm_export_child(parent, pwm);
+ if (ret < 0)
+ pwm_put(pwm);
+
+ return ret ? : len;
+}
+
+static ssize_t pwm_unexport_store(struct device *parent,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct pwm_chip *chip = dev_get_drvdata(parent);
+ unsigned int hwpwm;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &hwpwm);
+ if (ret < 0)
+ return ret;
+
+ if (hwpwm >= chip->npwm)
+ return -ENODEV;
+
+ ret = pwm_unexport_child(parent, &chip->pwms[hwpwm]);
+
+ return ret ? : len;
+}
+
+static ssize_t pwm_npwm_show(struct device *parent,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_chip *chip = dev_get_drvdata(parent);
+
+ return sprintf(buf, "%u\n", chip->npwm);
+}
+
+static struct device_attribute pwm_chip_attrs[] = {
+ __ATTR(export, 0200, NULL, pwm_export_store),
+ __ATTR(unexport, 0200, NULL, pwm_unexport_store),
+ __ATTR(npwm, 0444, pwm_npwm_show, NULL),
+ __ATTR_NULL,
+};
+
+static struct class pwm_class = {
+ .name = "pwm",
+ .owner = THIS_MODULE,
+ .dev_attrs = pwm_chip_attrs,
+};
+
+static int pwmchip_sysfs_match(struct device *parent, const void *data)
+{
+ return dev_get_drvdata(parent) == data;
+}
+
+void pwmchip_sysfs_export(struct pwm_chip *chip)
+{
+ struct device *parent;
+
+ /*
+ * If device_create() fails the pwm_chip is still usable by
+ * the kernel its just not exported.
+ */
+ parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip,
+ "pwmchip%d", chip->base);
+ if (IS_ERR(parent)) {
+ dev_warn(chip->dev,
+ "device_create failed for pwm_chip sysfs export\n");
+ }
+}
+
+void pwmchip_sysfs_unexport(struct pwm_chip *chip)
+{
+ struct device *parent;
+
+ parent = class_find_device(&pwm_class, NULL, chip,
+ pwmchip_sysfs_match);
+ if (parent) {
+ /* for class_find_device() */
+ put_device(parent);
+ device_unregister(parent);
+ }
+}
+
+static int __init pwm_sysfs_init(void)
+{
+ return class_register(&pwm_class);
+}
+subsys_initcall(pwm_sysfs_init);
OpenPOWER on IntegriCloud