[PATCH] leds: Add driver for PCA9622 LED driver chip.

[Martin Fuzzey <mfuzzey@parkeon.com>]

Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
---
 Documentation/devicetree/bindings/leds/pca9622.txt |   35 +++
 drivers/leds/Kconfig                               |    8 +
 drivers/leds/Makefile                              |    1 
 drivers/leds/leds-pca9622.c                        |  268 ++++++++++++++++++++
 4 files changed, 312 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/pca9622.txt
 create mode 100644 drivers/leds/leds-pca9622.c

diff --git a/Documentation/devicetree/bindings/leds/pca9622.txt b/Documentation/devicetree/bindings/leds/pca9622.txt
new file mode 100644
index 0000000..ac4f2f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/pca9622.txt
@@ -0,0 +1,35 @@
+LEDs connected to pca9622
+
+Required properties:
+- compatible : must be : "nxp,pca9622"
+- reg : i2c address
+
+Optional properties:
+- name-prefix : name prepended to label in /sys/class/leds defaults to "pca9622"
+
+Each led is represented as a sub-node of the nxp,pca922 device.
+
+LED sub-node properties:
+- reg : number of LED line (0 - 15)
+- label : (optional) see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger : (optional)
+   see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+leds@60 {
+	compatible = "nxp,pca9622";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	reg = <0x60>;
+	name-prefix = "antenna-board";
+	out0 {
+		label = "blue:target-3";
+		reg = <0>;
+	};
+	out3 {
+		label = "red:target-3";
+		reg = <3>;
+	};
+};
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a1b044e..afbbc7e 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -291,6 +291,14 @@ config LEDS_PCA955X
 	  LED driver chips accessed via the I2C bus.  Supported
 	  devices include PCA9550, PCA9551, PCA9552, and PCA9553.
 
+config LEDS_PCA9622
+	tristate "LED support for PCA9622 I2C chip"
+	depends on LEDS_CLASS
+	depends on I2C
+	help
+	  This option enables support for LEDs connected to the PCA9622
+	  LED driver chip accessed via the I2C bus.
+
 config LEDS_PCA963X
 	tristate "LED support for PCA963x I2C chip"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 79c5155..adbd075 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_LEDS_HP6XX)		+= leds-hp6xx.o
 obj-$(CONFIG_LEDS_OT200)		+= leds-ot200.o
 obj-$(CONFIG_LEDS_FSG)			+= leds-fsg.o
 obj-$(CONFIG_LEDS_PCA955X)		+= leds-pca955x.o
+obj-$(CONFIG_LEDS_PCA9622)		+= leds-pca9622.o
 obj-$(CONFIG_LEDS_PCA963X)		+= leds-pca963x.o
 obj-$(CONFIG_LEDS_DA903X)		+= leds-da903x.o
 obj-$(CONFIG_LEDS_DA9052)		+= leds-da9052.o
diff --git a/drivers/leds/leds-pca9622.c b/drivers/leds/leds-pca9622.c
new file mode 100644
index 0000000..3a19433
--- /dev/null
+++ b/drivers/leds/leds-pca9622.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright 2014 Parkeon
+ *
+ * Author: Martin Fuzzey <mfuzzey@parkeon.com>
+ *
+ * Based on leds-pca9622.c
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/leds.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+
+#define PCA9622_MAX_LEDS	16
+
+/* LED select registers determine the source that drives LED outputs */
+#define PCA9622_LED_OFF		0x0	/* LED driver off */
+#define PCA9622_LED_ON		0x1	/* LED driver on */
+#define PCA9622_LED_PWM		0x2	/* Controlled through PWM */
+#define PCA9622_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */
+
+#define PCA9622_MODE1		0x00
+#define PCA9622_MODE2		0x01
+#define PCA9622_PWM_BASE	0x02
+#define PCA9622_LEDOUT_BASE	0x14
+
+static const struct i2c_device_id pca9622_id[] = {
+	{ "pca9622", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pca9622_id);
+
+struct pca9622_led {
+	struct i2c_client *client;
+	struct work_struct work;
+	enum led_brightness brightness;
+	struct led_classdev led_cdev;
+	int led_num; /* 0 .. 15 potentially */
+	char name[32];
+};
+
+static void pca9622_led_work(struct work_struct *work)
+{
+	struct pca9622_led *pca9622 = container_of(work,
+		struct pca9622_led, work);
+	u8 ledout_reg = PCA9622_LEDOUT_BASE + pca9622->led_num / 4;
+	u8 ledout = i2c_smbus_read_byte_data(pca9622->client, ledout_reg);
+	int shift = 2 * (pca9622->led_num % 4);
+	u8 mask = 0x3 << shift;
+
+	switch (pca9622->brightness) {
+	case LED_FULL:
+		i2c_smbus_write_byte_data(pca9622->client, ledout_reg,
+			(ledout & ~mask) | (PCA9622_LED_ON << shift));
+		break;
+	case LED_OFF:
+		i2c_smbus_write_byte_data(pca9622->client, ledout_reg,
+			ledout & ~mask);
+		break;
+	default:
+		i2c_smbus_write_byte_data(pca9622->client,
+			PCA9622_PWM_BASE + pca9622->led_num,
+			pca9622->brightness);
+		i2c_smbus_write_byte_data(pca9622->client, ledout_reg,
+			(ledout & ~mask) | (PCA9622_LED_PWM << shift));
+		break;
+	}
+}
+
+static void pca9622_led_set(struct led_classdev *led_cdev,
+	enum led_brightness value)
+{
+	struct pca9622_led *pca9622;
+
+	pca9622 = container_of(led_cdev, struct pca9622_led, led_cdev);
+
+	pca9622->brightness = value;
+
+	/*
+	 * Must use workqueue for the actual I/O since I2C operations
+	 * can sleep.
+	 */
+	schedule_work(&pca9622->work);
+}
+
+static struct led_platform_data *pca9622_led_pdata_from_dt(struct device *dev)
+{
+	struct led_platform_data *pdata = NULL;
+#ifdef CONFIG_OF
+	struct device_node *np = dev->of_node;
+	struct device_node *child;
+	struct led_info *leds;
+	int num_leds;
+
+	num_leds = of_get_child_count(np);
+	if (num_leds == 0)
+		return NULL;  /* Optional */
+	if (num_leds > PCA9622_MAX_LEDS) {
+		dev_err(dev, "Too many child nodes max=%d\n", PCA9622_MAX_LEDS);
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	leds = devm_kzalloc(dev, PCA9622_MAX_LEDS * sizeof(*leds), GFP_KERNEL);
+	if (!leds)
+		return ERR_PTR(-ENOMEM);
+
+	for_each_child_of_node(np, child) {
+		int ret;
+		u32 line;
+		struct led_info led;
+
+		memset(&led, 0, sizeof(led));
+
+		ret = of_property_read_u32(child, "reg", &line);
+		if (ret) {
+			dev_err(dev, "Node '%s' missing line number (reg)\n",
+				child->name);
+			return ERR_PTR(ret);
+		}
+
+		led.name = child->name;
+		of_property_read_string(child, "label", &led.name);
+		of_property_read_string(child, "linux,default-trigger",
+							&led.default_trigger);
+
+		leds[line] = led;
+	}
+
+	pdata->leds = leds;
+	pdata->num_leds = PCA9622_MAX_LEDS;
+#endif
+	return pdata;
+}
+
+static int pca9622_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	const char *name_prefix = "pca9622";
+	struct pca9622_led *pca9622;
+	struct led_platform_data *pdata;
+	int i, ret;
+
+	of_property_read_string(client->dev.of_node, "name-prefix",
+							&name_prefix);
+	pdata = pca9622_led_pdata_from_dt(&client->dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+
+	if (!pdata) {
+		pdata = client->dev.platform_data;
+		if (pdata && (
+				pdata->num_leds <= 0 ||
+				pdata->num_leds > PCA9622_MAX_LEDS)
+		) {
+			dev_err(&client->dev,
+				"board data must define 0-%d LEDs",
+				PCA9622_MAX_LEDS);
+			return -EINVAL;
+		}
+	}
+
+	ret = i2c_smbus_read_byte_data(client, 0);
+	if (ret < 0)
+		return ret;
+
+	pca9622 = devm_kzalloc(&client->dev,
+			PCA9622_MAX_LEDS * sizeof(*pca9622), GFP_KERNEL);
+	if (!pca9622)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, pca9622);
+
+	for (i = 0; i < PCA9622_MAX_LEDS; i++) {
+		pca9622[i].client = client;
+		pca9622[i].led_num = i;
+
+		/* Platform data can specify LED names and default triggers */
+		if (pdata && i < pdata->num_leds) {
+			if (pdata->leds[i].name)
+				snprintf(pca9622[i].name,
+					 sizeof(pca9622[i].name), "%s:%s",
+					 name_prefix,
+					 pdata->leds[i].name);
+			if (pdata->leds[i].default_trigger)
+				pca9622[i].led_cdev.default_trigger =
+					pdata->leds[i].default_trigger;
+		}
+
+		if (strlen(pca9622[i].name) == 0)
+			snprintf(pca9622[i].name, sizeof(pca9622[i].name),
+						"%s:%d", name_prefix, i);
+
+		pca9622[i].led_cdev.name = pca9622[i].name;
+		pca9622[i].led_cdev.brightness_set = pca9622_led_set;
+
+		INIT_WORK(&pca9622[i].work, pca9622_led_work);
+
+		ret = led_classdev_register(&client->dev, &pca9622[i].led_cdev);
+		if (ret < 0)
+			goto exit;
+	}
+
+	/* Disable LED all-call address and set normal mode */
+	i2c_smbus_write_byte_data(client, PCA9622_MODE1, 0x00);
+
+	/* Turn off LEDs */
+	for (i = 0; i < PCA9622_MAX_LEDS / 4; i++)
+		i2c_smbus_write_byte_data(client, PCA9622_LEDOUT_BASE + i, 0);
+
+	return 0;
+
+exit:
+	while (i--) {
+		led_classdev_unregister(&pca9622[i].led_cdev);
+		cancel_work_sync(&pca9622[i].work);
+	}
+
+	return ret;
+}
+
+static int pca9622_remove(struct i2c_client *client)
+{
+	struct pca9622_led *pca9622 = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 0; i < PCA9622_MAX_LEDS; i++) {
+		led_classdev_unregister(&pca9622[i].led_cdev);
+		cancel_work_sync(&pca9622[i].work);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_pca9622_leds_match[] = {
+	{ .compatible =  "nxp,pca9622"},
+	{},
+};
+
+static struct i2c_driver pca9622_driver = {
+	.driver = {
+		.name	= "leds-pca9622",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(of_pca9622_leds_match),
+	},
+	.probe	= pca9622_probe,
+	.remove	= pca9622_remove,
+	.id_table = pca9622_id,
+};
+
+module_i2c_driver(pca9622_driver);
+
+MODULE_AUTHOR("Martin Fuzzey <mfuzzey@parkeon.com>");
+MODULE_DESCRIPTION("PCA9622 LED driver");
+MODULE_LICENSE("GPL v2");