drivers/leds: add driver for PCA9633 I2C chip

Driver for the PCA9633 I2C chip supporting four LEDs and 255 brightness
levels.

[akpm@linux-foundation.org: fix kcalloc() call]
[axel.lin@gmail.com: fix kcalloc parameters swapped]
Signed-off-by: Peter Meerwald <p.meerwald@bct-electronic.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 195 insertions, 0 deletions

diff --git a/drivers/leds/leds-pca9633.c b/drivers/leds/leds-pca9633.c
new file mode 100644
index 000000000000..80cb61adc2d6
--- /dev/null
+++ b/drivers/leds/leds-pca9633.c
@@ -0,0 +1,195 @@
+/*
+ * Copyright 2011 bct electronic GmbH
+ *
+ * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
+ *
+ * Based on leds-pca955x.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.
+ *
+ * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
+ *
+ */
+
+#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>
+
+/* LED select registers determine the source that drives LED outputs */
+#define PCA9633_LED_OFF         0x0     /* LED driver off */
+#define PCA9633_LED_ON          0x1     /* LED driver on */
+#define PCA9633_LED_PWM         0x2     /* Controlled through PWM */
+#define PCA9633_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
+
+#define PCA9633_MODE1           0x00
+#define PCA9633_MODE2           0x01
+#define PCA9633_PWM_BASE        0x02
+#define PCA9633_LEDOUT          0x08
+
+static const struct i2c_device_id pca9633_id[] = {
+        { "pca9633", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, pca9633_id);
+
+struct pca9633_led {
+        struct i2c_client *client;
+        struct work_struct work;
+        enum led_brightness brightness;
+        struct led_classdev led_cdev;
+        int led_num; /* 0 .. 3 potentially */
+        char name[32];
+};
+
+static void pca9633_led_work(struct work_struct *work)
+{
+        struct pca9633_led *pca9633 = container_of(work,
+                struct pca9633_led, work);
+        u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
+        int shift = 2 * pca9633->led_num;
+        u8 mask = 0x3 << shift;
+
+        switch (pca9633->brightness) {
+        case LED_FULL:
+                i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
+                        (ledout & ~mask) | (PCA9633_LED_ON << shift));
+                break;
+        case LED_OFF:
+                i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
+                        ledout & ~mask);
+                break;
+        default:
+                i2c_smbus_write_byte_data(pca9633->client,
+                        PCA9633_PWM_BASE + pca9633->led_num,
+                        pca9633->brightness);
+                i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
+                        (ledout & ~mask) | (PCA9633_LED_PWM << shift));
+                break;
+        }
+}
+
+static void pca9633_led_set(struct led_classdev *led_cdev,
+        enum led_brightness value)
+{
+        struct pca9633_led *pca9633;
+
+        pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
+
+        pca9633->brightness = value;
+
+        /*
+         * Must use workqueue for the actual I/O since I2C operations
+         * can sleep.
+         */
+        schedule_work(&pca9633->work);
+}
+
+static int __devinit pca9633_probe(struct i2c_client *client,
+                                        const struct i2c_device_id *id)
+{
+        struct pca9633_led *pca9633;
+        struct i2c_adapter *adapter;
+        struct led_platform_data *pdata;
+        int i, err;
+
+        adapter = to_i2c_adapter(client->dev.parent);
+        pdata = client->dev.platform_data;
+
+        if (pdata) {
+                if (pdata->num_leds <= 0 || pdata->num_leds > 4) {
+                        dev_err(&client->dev, "board info must claim at most 4 LEDs");
+                        return -EINVAL;
+                }
+        }
+
+        pca9633 = kcalloc(4, sizeof(*pca9633), GFP_KERNEL);
+        if (!pca9633)
+                return -ENOMEM;
+
+        i2c_set_clientdata(client, pca9633);
+
+        for (i = 0; i < 4; i++) {
+                pca9633[i].client = client;
+                pca9633[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(pca9633[i].name,
+                                         sizeof(pca9633[i].name), "pca9633:%s",
+                                         pdata->leds[i].name);
+                        if (pdata->leds[i].default_trigger)
+                                pca9633[i].led_cdev.default_trigger =
+                                        pdata->leds[i].default_trigger;
+                } else {
+                        snprintf(pca9633[i].name, sizeof(pca9633[i].name),
+                                 "pca9633:%d", i);
+                }
+
+                pca9633[i].led_cdev.name = pca9633[i].name;
+                pca9633[i].led_cdev.brightness_set = pca9633_led_set;
+
+                INIT_WORK(&pca9633[i].work, pca9633_led_work);
+
+                err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
+                if (err < 0)
+                        goto exit;
+        }
+
+        /* Disable LED all-call address and set normal mode */
+        i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00);
+
+        /* Turn off LEDs */
+        i2c_smbus_write_byte_data(client, PCA9633_LEDOUT, 0x00);
+
+        return 0;
+
+exit:
+        while (i--) {
+                led_classdev_unregister(&pca9633[i].led_cdev);
+                cancel_work_sync(&pca9633[i].work);
+        }
+
+        kfree(pca9633);
+
+        return err;
+}
+
+static int __devexit pca9633_remove(struct i2c_client *client)
+{
+        struct pca9633_led *pca9633 = i2c_get_clientdata(client);
+        int i;
+
+        for (i = 0; i < 4; i++) {
+                led_classdev_unregister(&pca9633[i].led_cdev);
+                cancel_work_sync(&pca9633[i].work);
+        }
+
+        kfree(pca9633);
+
+        return 0;
+}
+
+static struct i2c_driver pca9633_driver = {
+        .driver = {
+                .name   = "leds-pca9633",
+                .owner  = THIS_MODULE,
+        },
+        .probe  = pca9633_probe,
+        .remove = __devexit_p(pca9633_remove),
+        .id_table = pca9633_id,
+};
+
+module_i2c_driver(pca9633_driver);
+
+MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
+MODULE_DESCRIPTION("PCA9633 LED driver");
+MODULE_LICENSE("GPL v2");