leds-pwm: add note/frequency support

1 files changed, 234 insertions, 3 deletions

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index 666daf77872e..8607c34036da 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -17,17 +17,56 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/fb.h>
+#include <linux/ctype.h>
 #include <linux/leds.h>
 #include <linux/err.h>
 #include <linux/pwm.h>
 #include <linux/leds_pwm.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
+#include "leds.h"
+
+/* lowercase notes are an octave higher*/
+/* n means move up n octaves */
+/* Note: sharp (#) or flat (_) precedes note that it applies to */
+unsigned base_A_G[] = {
+	36363636,	/* "A",	27.50 hz, 1250 cm */
+	32396317,	/* "B",	30.87 hz, 1110 cm */
+	61156103,	/* "C",	16.35 hz, 2100 cm */
+	54483894,	/* "D",	18.35 hz, 1870 cm */
+	48539631,	/* "E",	20.60 hz, 1670 cm */
+	45815311,	/* "F",	21.83 hz, 1580 cm */
+	40816802,	/* "G",	24.50 hz, 1400 cm */
+};
+unsigned sharp_A_G[] = {
+	34322702,	/* "#A", "_B"	29.14 hz, 1180 cm */
+	0,		/* "B",		30.87 hz, 1110 cm */
+	57723675,	/* "#C", "_D"	17.32 hz, 1990 cm */
+	51425948,	/* "#D", "_E"	19.45 hz, 1770 cm */
+	0,		/* "E",		20.60 hz, 1670 cm */
+	43243895,	/* "#F", "_G"	23.12 hz, 1490 cm */
+	38525931,	/* "#G", "_A"	25.96 hz, 1320 cm */
+};
+unsigned flat_A_G[] = {
+	38525931,	/* "_A"	25.96 hz, 1320 cm */
+	34322702,	/* "_B"	29.14 hz, 1180 cm */
+	0,		/* "C",	16.35 hz, 2100 cm */
+	57723675,	/* "_D" 17.32 hz, 1990 cm */
+	51425948,	/* "_E"	19.45 hz, 1770 cm */
+	0,		/* "F",	21.83 hz, 1580 cm */
+	43243895,	/* "_G"	23.12 hz, 1490 cm */
+};
 
 struct led_pwm_data {
 	struct led_classdev	cdev;
 	struct pwm_device	*pwm;
 	unsigned int 		active_low;
 	unsigned int		period;
+	unsigned char		octave;
+#define NM_NORMAL 0
+#define NM_SHARP 1
+#define NM_FLAT 2
+	unsigned char		note_mode;
 };
 
 static void led_pwm_set(struct led_classdev *led_cdev,
@@ -38,15 +77,187 @@ static void led_pwm_set(struct led_classdev *led_cdev,
 	unsigned int max = led_dat->cdev.max_brightness;
 	unsigned int period =  led_dat->period;
 
-	if (brightness == 0) {
-		pwm_config(led_dat->pwm, 0, period);
+	if (period == 0)
 		pwm_disable(led_dat->pwm);
+	else if (brightness == 0) {
+		pwm_config(led_dat->pwm, 0, period);
+		pwm_enable(led_dat->pwm);
 	} else {
 		pwm_config(led_dat->pwm, brightness * period / max, period);
 		pwm_enable(led_dat->pwm);
 	}
 }
 
+static ssize_t led_frequency_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	unsigned int period =  led_dat->period;
+	unsigned int freq = period ? 1000000000 / period : 0;
+
+	return sprintf(buf, "%u\n", freq);
+}
+
+static ssize_t led_frequency_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	ssize_t ret = -EINVAL;
+	char *after;
+	unsigned long freq = simple_strtoul(buf, &after, 10);
+	size_t count = after - buf;
+
+	if (*after && isspace(*after))
+		count++;
+
+	if (count == size) {
+		ret = count;
+
+		led_dat->period = freq ? 1000000000 / freq : 0;
+		if (!led_cdev->brightness)
+			led_cdev->brightness = led_cdev->max_brightness >> 1;
+		led_set_brightness(led_cdev, led_cdev->brightness);
+	}
+
+	return ret;
+}
+static ssize_t led_period_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	unsigned int period =  led_dat->period;
+
+	return sprintf(buf, "%u\n", period);
+}
+
+static ssize_t led_period_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	ssize_t ret = -EINVAL;
+	char *after;
+	unsigned long period = simple_strtoul(buf, &after, 10);
+	size_t count = after - buf;
+
+	if (*after && isspace(*after))
+		count++;
+
+	if (count == size) {
+		ret = count;
+		led_dat->period = period;
+		led_set_brightness(led_cdev, led_cdev->brightness);
+	}
+
+	return ret;
+}
+
+static ssize_t led_note_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	unsigned int period =  led_dat->period;
+	unsigned i;
+	int octave = 0;
+	unsigned best = 0;
+	unsigned best_err = 0xffffffff;
+	char note_mode = 0;
+
+	if (period == 0)
+		return sprintf(buf, " \n");
+
+	while (period < base_A_G[2]) {
+		octave++;
+		period <<= 1;
+	}
+	while (period > base_A_G[2]) {
+		octave--;
+		period >>= 1;
+	}
+	for (i = 0; i < 7; i++) {
+		unsigned err = (base_A_G[i] > period) ? (base_A_G[i] - period) :
+			(period - base_A_G[i]);
+		if (best_err > err) {
+			best = i;
+			best_err = err;
+			note_mode = 0;
+		}
+		err = (sharp_A_G[i] > period) ? (sharp_A_G[i] - period) :
+			(period - sharp_A_G[i]);
+		if (best_err > err) {
+			best = i;
+			best_err = err;
+			note_mode = '#';
+		}
+	}
+	return sprintf(buf, "%u%s%c\n", octave, &note_mode, 'A' + best);
+}
+
+static ssize_t led_note_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	size_t count = 0;
+	while (count < size) {
+		char octave = led_dat->octave;
+		char note_mode = led_dat->note_mode;
+		char c = *buf++;
+		int period = -1;
+		count++;
+		if (c == ' ')
+			period = 0;
+		else if (c == '_')
+			note_mode = NM_FLAT;
+		else if (c == '#')
+			note_mode = NM_SHARP;
+		else if ((c >= '0') && (c <= '9')) {
+			octave = c - '0';
+			led_dat->octave = octave;
+		} else {
+			if ((c >= 'a') && (c <= 'g')) {
+				octave++;
+				c -= 'a' - 'A';
+			}
+			if ((c >= 'A') && (c <= 'G')) {
+				c -= 'A';
+				if (note_mode == NM_NORMAL)
+					period = base_A_G[(int)c];
+				else if (note_mode == NM_SHARP)
+					period = sharp_A_G[(int)c];
+				else if (note_mode == NM_FLAT)
+					period = flat_A_G[(int)c];
+			}
+		}
+		led_dat->note_mode = note_mode;
+		if (period >= 0) {
+			period >>= octave;
+			led_dat->period = period;
+			if (!led_cdev->brightness)
+				led_cdev->brightness = led_cdev->max_brightness >> 1;
+			led_set_brightness(led_cdev, led_cdev->brightness);
+			led_dat->note_mode = NM_NORMAL;
+			if (count < size)
+				msleep(period ? 1000 : 100);
+		}
+	}
+	return count;
+}
+
+static DEVICE_ATTR(note, 0644, led_note_show, led_note_store);
+static DEVICE_ATTR(frequency, 0644, led_frequency_show, led_frequency_store);
+static DEVICE_ATTR(period, 0644, led_period_show, led_period_store);
+
 static int led_pwm_probe(struct platform_device *pdev)
 {
 	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
@@ -62,7 +273,9 @@ static int led_pwm_probe(struct platform_device *pdev)
 	if (!leds_data)
 		return -ENOMEM;
 
-	for (i = 0; i < pdata->num_leds; i++) {
+	i = 0;
+	while (i < pdata->num_leds) {
+		int rc;
 		cur_led = &pdata->leds[i];
 		led_dat = &leds_data[i];
 
@@ -78,6 +291,7 @@ static int led_pwm_probe(struct platform_device *pdev)
 		led_dat->cdev.name = cur_led->name;
 		led_dat->cdev.default_trigger = cur_led->default_trigger;
 		led_dat->active_low = cur_led->active_low;
+		led_dat->octave = 4;
 		led_dat->period = cur_led->pwm_period_ns;
 		led_dat->cdev.brightness_set = led_pwm_set;
 		led_dat->cdev.brightness = LED_OFF;
@@ -89,6 +303,20 @@ static int led_pwm_probe(struct platform_device *pdev)
 			pwm_free(led_dat->pwm);
 			goto err;
 		}
+
+		i++;
+		/* register the attributes */
+		rc = device_create_file(led_dat->cdev.dev, &dev_attr_frequency);
+		if (rc)
+			goto err;
+		rc = device_create_file(led_dat->cdev.dev, &dev_attr_period);
+		if (rc) {
+			goto err;
+		}
+		rc = device_create_file(led_dat->cdev.dev, &dev_attr_note);
+		if (rc) {
+			goto err;
+		}
 	}
 
 	platform_set_drvdata(pdev, leds_data);
@@ -98,6 +326,9 @@ static int led_pwm_probe(struct platform_device *pdev)
 err:
 	if (i > 0) {
 		for (i = i - 1; i >= 0; i--) {
+			device_remove_file(led_dat->cdev.dev, &dev_attr_note);
+			device_remove_file(led_dat->cdev.dev, &dev_attr_frequency);
+			device_remove_file(led_dat->cdev.dev, &dev_attr_period);
 			led_classdev_unregister(&leds_data[i].cdev);
 			pwm_free(leds_data[i].pwm);
 		}