leds: Add pca9532 led driver

NXP pca9532 is a LED dimmer/controller attached to i2c bus.  It allows
attaching upto 16 leds which can either be on, off or dimmed and/or blinked
with the two PWM modulators available.

This driver is a "new-style" i2c driver that adheres to the driver model and
implements the led framework api.  Since the leds connected to the driver are
platform specific, it is only useful when platform data is passed to the
driver to define what leds are connected to which pins.

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

3 files changed, 346 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 86a369b..1c35dfa 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -103,6 +103,14 @@ config LEDS_HP6XX
 	  This option enables led support for the handheld
 	  HP Jornada 620/660/680/690.
 
+config LEDS_PCA9532
+	tristate "LED driver for PCA9532 dimmer"
+	depends on LEDS_CLASS && I2C && INPUT && EXPERIMENTAL
+	help
+	  This option enables support for NXP pca9532
+	  led controller. It is generally only usefull
+	  as a platform driver
+
 config LEDS_GPIO
 	tristate "LED Support for GPIO connected LEDs"
 	depends on LEDS_CLASS && GENERIC_GPIO
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 973d626..7156f99 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_LEDS_WRAP)			+= leds-wrap.o
 obj-$(CONFIG_LEDS_H1940)		+= leds-h1940.o
 obj-$(CONFIG_LEDS_COBALT_QUBE)		+= leds-cobalt-qube.o
 obj-$(CONFIG_LEDS_COBALT_RAQ)		+= leds-cobalt-raq.o
+obj-$(CONFIG_LEDS_PCA9532)		+= leds-pca9532.o
 obj-$(CONFIG_LEDS_GPIO)			+= leds-gpio.o
 obj-$(CONFIG_LEDS_CM_X270)              += leds-cm-x270.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
new file mode 100644
index 0000000..4064d4f
--- /dev/null
+++ b/drivers/leds/leds-pca9532.c
@@ -0,0 +1,337 @@
+/*
+ * pca9532.c - 16-bit Led dimmer
+ *
+ * Copyright (C) 2008 Riku Voipio <riku.voipio@movial.fi>
+ *
+ * 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; version 2 of the License.
+ *
+ * Datasheet: http://www.nxp.com/acrobat/datasheets/PCA9532_3.pdf
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/input.h>
+#include <linux/mutex.h>
+#include <linux/leds-pca9532.h>
+
+static const unsigned short normal_i2c[] = { /*0x60,*/ I2C_CLIENT_END};
+I2C_CLIENT_INSMOD_1(pca9532);
+
+#define PCA9532_REG_PSC(i) (0x2+(i)*2)
+#define PCA9532_REG_PWM(i) (0x3+(i)*2)
+#define PCA9532_REG_LS0  0x6
+#define LED_REG(led) ((led>>2)+PCA9532_REG_LS0)
+#define LED_NUM(led) (led & 0x3)
+
+#define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)
+
+struct pca9532_data {
+	struct i2c_client *client;
+	struct pca9532_led leds[16];
+	struct mutex update_lock;
+	struct input_dev    *idev;
+	u8 pwm[2];
+	u8 psc[2];
+};
+
+static int pca9532_probe(struct i2c_client *client,
+	const struct i2c_device_id *id);
+static int pca9532_remove(struct i2c_client *client);
+
+static const struct i2c_device_id pca9532_id[] = {
+	{ "pca9532", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, pca9532_id);
+
+static struct i2c_driver pca9532_driver = {
+	.driver = {
+		.name   = "pca9532",
+	},
+	.probe  = pca9532_probe,
+	.remove = pca9532_remove,
+	.id_table = pca9532_id,
+};
+
+/* We have two pwm/blinkers, but 16 possible leds to drive. Additionaly,
+ * the clever Thecus people are using one pwm to drive the beeper. So,
+ * as a compromise we average one pwm to the values requested by all
+ * leds that are not ON/OFF.
+ * */
+static int pca9532_setpwm(struct i2c_client *client, int pwm, int blink,
+	enum led_brightness value)
+{
+	int a = 0, b = 0, i = 0;
+	struct pca9532_data *data = i2c_get_clientdata(client);
+	for (i = 0; i < 16; i++) {
+		if (data->leds[i].type == PCA9532_TYPE_LED &&
+			data->leds[i].state == PCA9532_PWM0+pwm) {
+				a++;
+				b += data->leds[i].ldev.brightness;
+		}
+	}
+	if (a == 0) {
+		dev_err(&client->dev,
+		"fear of division by zero %d/%d, wanted %d\n",
+			b, a, value);
+		return -EINVAL;
+	}
+	b = b/a;
+	if (b > 0xFF)
+		return -EINVAL;
+	mutex_lock(&data->update_lock);
+	data->pwm[pwm] = b;
+	i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(pwm),
+		data->pwm[pwm]);
+	data->psc[pwm] = blink;
+	i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(pwm),
+		data->psc[pwm]);
+	mutex_unlock(&data->update_lock);
+	return 0;
+}
+
+/* Set LED routing */
+static void pca9532_setled(struct pca9532_led *led)
+{
+	struct i2c_client *client = led->client;
+	struct pca9532_data *data = i2c_get_clientdata(client);
+	char reg;
+
+	mutex_lock(&data->update_lock);
+	reg = i2c_smbus_read_byte_data(client, LED_REG(led->id));
+	/* zero led bits */
+	reg = reg & ~(0x3<<LED_NUM(led->id)*2);
+	/* set the new value */
+	reg = reg | (led->state << LED_NUM(led->id)*2);
+	i2c_smbus_write_byte_data(client, LED_REG(led->id), reg);
+	mutex_unlock(&data->update_lock);
+}
+
+static void pca9532_set_brightness(struct led_classdev *led_cdev,
+	enum led_brightness value)
+{
+	int err = 0;
+	struct pca9532_led *led = ldev_to_led(led_cdev);
+
+	if (value == LED_OFF)
+		led->state = PCA9532_OFF;
+	else if (value == LED_FULL)
+		led->state = PCA9532_ON;
+	else {
+		led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
+		err = pca9532_setpwm(led->client, 0, 0, value);
+		if (err)
+			return; /* XXX: led api doesn't allow error code? */
+	}
+	pca9532_setled(led);
+}
+
+static int pca9532_set_blink(struct led_classdev *led_cdev,
+	unsigned long *delay_on, unsigned long *delay_off)
+{
+	struct pca9532_led *led = ldev_to_led(led_cdev);
+	struct i2c_client *client = led->client;
+	int psc;
+
+	if (*delay_on == 0 && *delay_off == 0) {
+	/* led subsystem ask us for a blink rate */
+		*delay_on  = 1000;
+		*delay_off = 1000;
+	}
+	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
+		return -EINVAL;
+
+	/* Thecus specific: only use PSC/PWM 0 */
+	psc = (*delay_on * 152-1)/1000;
+	return pca9532_setpwm(client, 0, psc, led_cdev->brightness);
+}
+
+int pca9532_event(struct input_dev *dev, unsigned int type, unsigned int code,
+	int value)
+{
+	struct pca9532_data *data = input_get_drvdata(dev);
+
+	if (type != EV_SND && (code != SND_BELL || code != SND_TONE))
+		return -1;
+
+	/* XXX: allow different kind of beeps with psc/pwm modifications */
+	if (value > 1 && value < 32767)
+		data->pwm[1] = 127;
+	else
+		data->pwm[1] = 0;
+
+	dev_info(&dev->dev, "setting beep to %d \n", data->pwm[1]);
+	mutex_lock(&data->update_lock);
+	i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(1),
+		data->pwm[1]);
+	mutex_unlock(&data->update_lock);
+
+	return 0;
+}
+
+static int pca9532_configure(struct i2c_client *client,
+	struct pca9532_data *data, struct pca9532_platform_data *pdata)
+{
+	int i, err = 0;
+
+	for (i = 0; i < 2; i++)	{
+		data->pwm[i] = pdata->pwm[i];
+		data->psc[i] = pdata->psc[i];
+		i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(i),
+			data->pwm[i]);
+		i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(i),
+			data->psc[i]);
+	}
+
+	for (i = 0; i < 16; i++) {
+		struct pca9532_led *led = &data->leds[i];
+		struct pca9532_led *pled = &pdata->leds[i];
+		led->client = client;
+		led->id = i;
+		led->type = pled->type;
+		switch (led->type) {
+		case PCA9532_TYPE_NONE:
+			break;
+		case PCA9532_TYPE_LED:
+			led->state = pled->state;
+			led->name =  pled->name;
+			led->ldev.name = led->name;
+			led->ldev.brightness = LED_OFF;
+			led->ldev.brightness_set = pca9532_set_brightness;
+			led->ldev.blink_set = pca9532_set_blink;
+			if (led_classdev_register(&client->dev,
+				&led->ldev) < 0)	{
+				dev_err(&client->dev,
+					"couldn't register LED %s\n",
+					led->name);
+				goto exit;
+			}
+			pca9532_setled(led);
+			break;
+		case PCA9532_TYPE_N2100_BEEP:
+			BUG_ON(data->idev);
+			led->state = PCA9532_PWM1;
+			pca9532_setled(led);
+			data->idev = input_allocate_device();
+			if (data->idev == NULL) {
+				err = -ENOMEM;
+				goto exit;
+			}
+			data->idev->name = pled->name;
+			data->idev->phys = "i2c/pca9532";
+			data->idev->id.bustype = BUS_HOST;
+			data->idev->id.vendor  = 0x001f;
+			data->idev->id.product = 0x0001;
+			data->idev->id.version = 0x0100;
+			data->idev->evbit[0] = BIT_MASK(EV_SND);
+			data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
+						BIT_MASK(SND_TONE);
+			data->idev->event = pca9532_event;
+			input_set_drvdata(data->idev, data);
+			err = input_register_device(data->idev);
+			if (err) {
+				input_free_device(data->idev);
+				data->idev = NULL;
+				goto exit;
+			}
+			break;
+		}
+	}
+	return 0;
+
+exit:
+	if (i > 0)
+		for (i = i - 1; i >= 0; i--)
+			switch (data->leds[i].type) {
+			case PCA9532_TYPE_NONE:
+				break;
+			case PCA9532_TYPE_LED:
+				led_classdev_unregister(&data->leds[i].ldev);
+				break;
+			case PCA9532_TYPE_N2100_BEEP:
+				if (data->idev != NULL) {
+					input_unregister_device(data->idev);
+					input_free_device(data->idev);
+					data->idev = NULL;
+				}
+				break;
+			}
+
+	return err;
+
+}
+
+static int pca9532_probe(struct i2c_client *client,
+	const struct i2c_device_id *id)
+{
+	struct pca9532_data *data = i2c_get_clientdata(client);
+	struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
+
+	if (!i2c_check_functionality(client->adapter,
+		I2C_FUNC_SMBUS_BYTE_DATA))
+		return -EIO;
+
+	data = kzalloc(sizeof(struct pca9532_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	dev_info(&client->dev, "setting platform data\n");
+	i2c_set_clientdata(client, data);
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	if (pca9532_pdata == NULL)
+		return -EIO;
+
+	pca9532_configure(client, data, pca9532_pdata);
+	return 0;
+
+}
+
+static int pca9532_remove(struct i2c_client *client)
+{
+	struct pca9532_data *data = i2c_get_clientdata(client);
+	int i;
+	for (i = 0; i < 16; i++)
+		switch (data->leds[i].type) {
+		case PCA9532_TYPE_NONE:
+			break;
+		case PCA9532_TYPE_LED:
+			led_classdev_unregister(&data->leds[i].ldev);
+			break;
+		case PCA9532_TYPE_N2100_BEEP:
+			if (data->idev != NULL) {
+				input_unregister_device(data->idev);
+				input_free_device(data->idev);
+				data->idev = NULL;
+			}
+			break;
+		}
+
+	kfree(data);
+	i2c_set_clientdata(client, NULL);
+	return 0;
+}
+
+static int __init pca9532_init(void)
+{
+	return i2c_add_driver(&pca9532_driver);
+}
+
+static void __exit pca9532_exit(void)
+{
+	i2c_del_driver(&pca9532_driver);
+}
+
+MODULE_AUTHOR("Riku Voipio <riku.voipio@movial.fi>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("PCA 9532 LED dimmer");
+
+module_init(pca9532_init);
+module_exit(pca9532_exit);
+