--- /dev/null
+/*
+ * ROHM 1780GLI Ambient Light Sensor Driver
+ *
+ * Copyright (C) 2016 Linaro Ltd.
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ * Loosely based on the previous BH1780 ALS misc driver
+ * Copyright (C) 2010 Texas Instruments
+ * Author: Hemanth V <hemanthv@ti.com>
+ */
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/bitops.h>
+
+#define BH1780_CMD_BIT BIT(7)
+#define BH1780_REG_CONTROL 0x00
+#define BH1780_REG_PARTID 0x0A
+#define BH1780_REG_MANFID 0x0B
+#define BH1780_REG_DLOW 0x0C
+#define BH1780_REG_DHIGH 0x0D
+
+#define BH1780_REVMASK GENMASK(3,0)
+#define BH1780_POWMASK GENMASK(1,0)
+#define BH1780_POFF (0x0)
+#define BH1780_PON (0x3)
+
+/* power on settling time in ms */
+#define BH1780_PON_DELAY 2
+/* max time before value available in ms */
+#define BH1780_INTERVAL 250
+
+struct bh1780_data {
+ struct i2c_client *client;
+};
+
+static int bh1780_write(struct bh1780_data *bh1780, u8 reg, u8 val)
+{
+ int ret = i2c_smbus_write_byte_data(bh1780->client,
+ BH1780_CMD_BIT | reg,
+ val);
+ if (ret < 0)
+ dev_err(&bh1780->client->dev,
+ "i2c_smbus_write_byte_data failed error "
+ "%d, register %01x\n",
+ ret, reg);
+ return ret;
+}
+
+static int bh1780_read(struct bh1780_data *bh1780, u8 reg)
+{
+ int ret = i2c_smbus_read_byte_data(bh1780->client,
+ BH1780_CMD_BIT | reg);
+ if (ret < 0)
+ dev_err(&bh1780->client->dev,
+ "i2c_smbus_read_byte_data failed error "
+ "%d, register %01x\n",
+ ret, reg);
+ return ret;
+}
+
+static int bh1780_read_word(struct bh1780_data *bh1780, u8 reg)
+{
+ int ret = i2c_smbus_read_word_data(bh1780->client,
+ BH1780_CMD_BIT | reg);
+ if (ret < 0)
+ dev_err(&bh1780->client->dev,
+ "i2c_smbus_read_word_data failed error "
+ "%d, register %01x\n",
+ ret, reg);
+ return ret;
+}
+
+static int bh1780_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg, unsigned int writeval,
+ unsigned int *readval)
+{
+ struct bh1780_data *bh1780 = iio_priv(indio_dev);
+ int ret;
+
+ if (!readval)
+ bh1780_write(bh1780, (u8)reg, (u8)writeval);
+
+ ret = bh1780_read(bh1780, (u8)reg);
+ if (ret < 0)
+ return ret;
+
+ *readval = ret;
+
+ return 0;
+}
+
+static int bh1780_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct bh1780_data *bh1780 = iio_priv(indio_dev);
+ int value;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_LIGHT:
+ pm_runtime_get_sync(&bh1780->client->dev);
+ value = bh1780_read_word(bh1780, BH1780_REG_DLOW);
+ if (value < 0)
+ return value;
+ pm_runtime_mark_last_busy(&bh1780->client->dev);
+ pm_runtime_put_autosuspend(&bh1780->client->dev);
+ *val = value;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_INT_TIME:
+ *val = 0;
+ *val2 = BH1780_INTERVAL * 1000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info bh1780_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = bh1780_read_raw,
+ .debugfs_reg_access = bh1780_debugfs_reg_access,
+};
+
+static const struct iio_chan_spec bh1780_channels[] = {
+ {
+ .type = IIO_LIGHT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_INT_TIME)
+ }
+};
+
+static int bh1780_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct bh1780_data *bh1780;
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ struct iio_dev *indio_dev;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
+ return -EIO;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*bh1780));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ bh1780 = iio_priv(indio_dev);
+ bh1780->client = client;
+ i2c_set_clientdata(client, indio_dev);
+
+ /* Power up the device */
+ ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
+ if (ret < 0)
+ return ret;
+ msleep(BH1780_PON_DELAY);
+ pm_runtime_get_noresume(&client->dev);
+ pm_runtime_set_active(&client->dev);
+ pm_runtime_enable(&client->dev);
+
+ ret = bh1780_read(bh1780, BH1780_REG_PARTID);
+ if (ret < 0)
+ goto out_disable_pm;
+ dev_info(&client->dev,
+ "Ambient Light Sensor, Rev : %lu\n",
+ (ret & BH1780_REVMASK));
+
+ /*
+ * As the device takes 250 ms to even come up with a fresh
+ * measurement after power-on, do not shut it down unnecessarily.
+ * Set autosuspend to a five seconds.
+ */
+ pm_runtime_set_autosuspend_delay(&client->dev, 5000);
+ pm_runtime_use_autosuspend(&client->dev);
+ pm_runtime_put(&client->dev);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &bh1780_info;
+ indio_dev->name = id->name;
+ indio_dev->channels = bh1780_channels;
+ indio_dev->num_channels = ARRAY_SIZE(bh1780_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto out_disable_pm;
+ return 0;
+
+out_disable_pm:
+ pm_runtime_put_noidle(&client->dev);
+ pm_runtime_disable(&client->dev);
+ return ret;
+}
+
+static int bh1780_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct bh1780_data *bh1780 = iio_priv(indio_dev);
+ int ret;
+
+ iio_device_unregister(indio_dev);
+ pm_runtime_get_sync(&client->dev);
+ pm_runtime_put_noidle(&client->dev);
+ pm_runtime_disable(&client->dev);
+ ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to power off\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int bh1780_runtime_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct bh1780_data *bh1780 = i2c_get_clientdata(client);
+ int ret;
+
+ ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
+ if (ret < 0) {
+ dev_err(dev, "failed to runtime suspend\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int bh1780_runtime_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct bh1780_data *bh1780 = i2c_get_clientdata(client);
+ int ret;
+
+ ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
+ if (ret < 0) {
+ dev_err(dev, "failed to runtime resume\n");
+ return ret;
+ }
+
+ /* Wait for power on, then for a value to be available */
+ msleep(BH1780_PON_DELAY + BH1780_INTERVAL);
+
+ return 0;
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops bh1780_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(bh1780_runtime_suspend,
+ bh1780_runtime_resume, NULL)
+};
+
+static const struct i2c_device_id bh1780_id[] = {
+ { "bh1780", 0 },
+ { },
+};
+
+MODULE_DEVICE_TABLE(i2c, bh1780_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_bh1780_match[] = {
+ { .compatible = "rohm,bh1780gli", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_bh1780_match);
+#endif
+
+static struct i2c_driver bh1780_driver = {
+ .probe = bh1780_probe,
+ .remove = bh1780_remove,
+ .id_table = bh1780_id,
+ .driver = {
+ .name = "bh1780",
+ .pm = &bh1780_dev_pm_ops,
+ .of_match_table = of_match_ptr(of_bh1780_match),
+ },
+};
+
+module_i2c_driver(bh1780_driver);
+
+MODULE_DESCRIPTION("ROHM BH1780GLI Ambient Light Sensor Driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
projects / platform / kernel / linux-exynos.git / commitdiff