Re: [PATCH v2] iio: light: Add support for UPISEMI uS5182d als and proximity sensor

From: Adriana Reus
Date: Wed Aug 05 2015 - 03:47:04 EST



On 04.08.2015 17:40, Peter Meerwald wrote:
On Tue, 4 Aug 2015, Adriana Reus wrote:

Add support for UPISEMI us5182d als and proximity sensor.
Supports raw readings.
Data sheet for this device can be found here:
http://www.upi-semi.com/temp/uS5182D-DS-P0103-temp.pdf

comments below
Thank you for the comments. Added answers inline, I'll address them in a new patch-set.

Signed-off-by: Adriana Reus <adriana.reus@xxxxxxxxx>
---
Changes since v1: added data-sheet link to commit message
drivers/iio/light/Kconfig | 10 +
drivers/iio/light/Makefile | 1 +
drivers/iio/light/us5182d.c | 539 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 550 insertions(+)
create mode 100644 drivers/iio/light/us5182d.c

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index a459341..0aa819d 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -285,6 +285,16 @@ config TSL4531
To compile this driver as a module, choose M here: the
module will be called tsl4531.

+config US5182D
+ tristate "UPISEMI light and proximity sensor"
+ depends on I2C
+ help
+ If you say yes here you get support for the UPISEMI US5182D
+ ambient light and proximity sensor.
+
+ This driver can also be built as a module. If so, the module
+ will be called us5182d.
+
config VCNL4000
tristate "VCNL4000 combined ALS and proximity sensor"
depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 91c74c0..528cc8f 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -27,4 +27,5 @@ obj-$(CONFIG_STK3310) += stk3310.o
obj-$(CONFIG_TCS3414) += tcs3414.o
obj-$(CONFIG_TCS3472) += tcs3472.o
obj-$(CONFIG_TSL4531) += tsl4531.o
+obj-$(CONFIG_US5182D) += us5182d.o
obj-$(CONFIG_VCNL4000) += vcnl4000.o
diff --git a/drivers/iio/light/us5182d.c b/drivers/iio/light/us5182d.c
new file mode 100644
index 0000000..6654bb0
--- /dev/null
+++ b/drivers/iio/light/us5182d.c
@@ -0,0 +1,539 @@
+/*
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * Driver for UPISEMI us5182d Proximity and Ambient Light Sensor.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * To do: Interrupt support.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/mutex.h>
+
+#define US5182D_REG_CFG0 0x00
+#define US5182D_REG_CFG1 0x01
+#define US5182D_REG_CFG2 0x02
+#define US5182D_REG_CFG3 0x03
+#define US5182D_REG_CFG4 0x10
+
+/*
+ * Registers for tuning the auto dark current cancelling feature.
+ * DARK_TH(reg 0x27,0x28) - threshold (counts) for auto dark cancelling.
+ * when ALS > DARK_TH --> ALS_Code = ALS - Upper(0x2A) * Dark
+ * when ALS < DARK_TH --> ALS_Code = ALS - Lower(0x29) * Dark
+ */
+#define US5182D_REG_UDARK_TH 0x27
+#define US5182D_REG_DARK_AUTO_EN 0x2b
+#define US5182D_REG_AUTO_LDARK_TH 0x29
+#define US5182D_REG_AUTO_HDARK_TH 0x2a
+
+/*
+ * power-mode - oneshot, non-interrupt, word mode access for
+ * als code, th registers.
+ */
+#define US5182D_REG_CFG0_DEFAULT 0x81
+
+/*
+ * no als fault queue, 16 bit als resolution (supports 12 and 14 also),
+ * max-range 12354.
+ */
+#define US5182D_REG_CFG1_DEFAULT 0x10
+
+/*
+ * 16 bit resolution for PX, x16 sensing amplifier for px
+ * supports [x1 x2 x4 x8 x16 x32 x64 x128]
+ */
+#define US5182D_REG_CFG2_DEFAULT 0x14
+
+/*
+ * led current : 100mA, supports [12.5 25 50 100] mA,
+ * interrupt source selection "px approach",
+ * [als or ps, als only, ps only, ps approach]
+ */
+#define US5182D_REG_CFG3_DEFAULT 0x3C
+
+/*
+ * led frequency ADC Clock/2 from [ADC Clock/2, /4, /8, /10]
+ * automatic 50/60 Hz ripple rejection disabled.
+ */
+#define US5182D_REG_CFG4_DEFAULT 0x00
+
+#define US5182D_REG_DARK_AUTO_EN_DEFAULT 0x80
+#define US5182D_REG_AUTO_LDARK_TH_DEFAULT 0x16
+#define US5182D_REG_AUTO_HDARK_TH_DEFAULT 0x00
+
+#define US5182D_REG_ADL 0x0c
+#define US5182D_REG_PDL 0x0e
+
+#define US5182D_REG_MODE_STORE 0x21
+#define US5182D_STORE_MODE 0x01
+
+#define US5182D_REG_CHIPID 0xb2
+
+#define US5182D_ONESHOT_EN_MASK BIT(6)
+#define US5182D_SHUTDOWN_EN_MASK BIT(7)
+#define US5182D_OPMODE_MASK GENMASK(5, 4)
+#define US5182D_AGAIN_MASK 0x07
+#define US5182D_OPMODE_ALS 0x01
+#define US5182D_OPMODE_PX 0x02
+#define US5182D_OPMODE_SHIFT 4
+#define US5182D_RESET_CHIP 0x01
+
+#define US5182D_CHIPID 0x26
+#define US5182D_DRV_NAME "us5182d"
+
+#define US5182D_GA_RESOLUTION 1000
+
+#define READ_BYTE 1

US5128D_ prefix?!
will do

+#define READ_WORD 2
+#define OPSTORE_SLEEP_TIME 20 /* ms */
+
+/* available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux*/

space before */

+static const int us5182d_scales[] = {188500, 107800, 61000, 33600, 19600, 7600,
+ 3900, 2100};
+
+/*
+ * experimental th's that work with US5182D sensor on evaluation board
+ * roughly between 12-32 lux
+ */
+static u16 us5182d_dark_ths_vals[] = {170, 200, 512, 512, 800, 2000, 4000,

const int

is 2x 512 correct?
it is intended

+ 8000};
+
+enum mode {
+ ALS_PX,

US5128D_ prefix
noted

+ ALS_ONLY,
+ PX_ONLY
+};
+
+struct us5182d_data {
+ struct i2c_client *client;
+ /* protect opmode */
+ struct mutex lock;
+
+ /* Glass attenuation factor */
+ u32 ga;
+
+ /* Dark gain tuning */
+ u16 lower_dark_th;
+ u16 upper_dark_th;
+ u16 *us5182d_dark_ths;
+
+ u8 opmode;
+};
+
+static IIO_CONST_ATTR(in_illuminance_scale_available,
+ "0.0021 0.0039 0.0076 0.0196 0.0336 0.061 0.1078 0.1885");
+
+static struct attribute *us5182d_attrs[] = {
+ &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group us5182d_attr_group = {
+ .attrs = us5182d_attrs,
+};
+
+static const struct {
+ u8 reg;
+ u8 val;
+} us5182d_regvals[] = {
+ {US5182D_REG_CFG0, US5182D_REG_CFG0_DEFAULT},
+ {US5182D_REG_CFG1, US5182D_REG_CFG1_DEFAULT},
+ {US5182D_REG_CFG2, US5182D_REG_CFG2_DEFAULT},
+ {US5182D_REG_CFG3, US5182D_REG_CFG3_DEFAULT},
+ {US5182D_REG_MODE_STORE, US5182D_STORE_MODE},
+ {US5182D_REG_CFG4, US5182D_REG_CFG4_DEFAULT},
+};
+
+static const struct iio_chan_spec us5182d_channels[] = {
+ {
+ .type = IIO_LIGHT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ },
+ {
+ .type = IIO_PROXIMITY,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ }
+};
+
+static int us5182d_read(struct i2c_client *client, u8 reg, int len, u8 *val)
+{
+ struct i2c_msg msg[2] = {
+ {
+ /* Write - use repeated start */
+ .addr = client->addr,
+ .flags = I2C_M_NOSTART,
+ .len = 1,
+ .buf = &reg
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = val
+ }
+ };
+
+ return i2c_transfer(client->adapter, msg, 2);
+}
+
+static int us5182d_read_byte_data(struct i2c_client *client, u8 reg)
+{
+ u8 val[1];
+ int ret;
+
+ ret = us5182d_read(client, reg, READ_BYTE, val);
+ return (ret < 0) ? ret : val[0];
+}
+
+static int us5182d_read_word_data(struct i2c_client *client, u8 reg)
+{
+ u8 val[2];
+ int ret;
+
+ ret = us5182d_read(client, reg, READ_WORD, val);

use le16_to_cpu()

+ return (ret < 0) ? ret : (val[0] | (val[1] << 8));
+}
+
+static int us5182d_get_als(struct us5182d_data *data)
+{
+ int ret;
+ unsigned long result;
+
+ ret = us5182d_read_word_data(data->client,
+ US5182D_REG_ADL);
+ if (ret < 0)
+ return ret;
+
+ result = ret * data->ga / US5182D_GA_RESOLUTION;
+ if (result > 0xffff)
+ result = 0xffff;
+
+ return result;
+}
+
+static int us5182d_set_opmode(struct us5182d_data *data, u8 mode)
+{
+ int ret;
+
+ ret = us5182d_read_byte_data(data->client, US5182D_REG_CFG0);
+ if (ret < 0)
+ return ret;
+
+ ret = ret | US5182D_ONESHOT_EN_MASK;
+
+ /* update mode */
+ ret = ret & ~US5182D_OPMODE_MASK;
+ ret = ret | (mode << US5182D_OPMODE_SHIFT);
+
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG0, ret);
+ if (ret < 0)
+ return ret;
+
+ if (mode == data->opmode)
+ return 0;
+
+ data->opmode = mode;
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_MODE_STORE,
+ US5182D_STORE_MODE);
+ if (ret < 0)
+ return ret;
+ msleep(OPSTORE_SLEEP_TIME);
+
+ return 0;
+}
+
+static int us5182d_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct us5182d_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_LIGHT:
+ mutex_lock(&data->lock);
+ ret = us5182d_set_opmode(data, US5182D_OPMODE_ALS);
+ if (ret < 0)
+ goto out_err;
+
+ ret = us5182d_get_als(data);
+ if (ret < 0)
+ goto out_err;
+ mutex_unlock(&data->lock);
+ *val = ret;
+ *val2 = 0;

no need to set val2
noted

+ return IIO_VAL_INT;
+ case IIO_PROXIMITY:
+ mutex_lock(&data->lock);
+ ret = us5182d_set_opmode(data, US5182D_OPMODE_PX);
+ if (ret < 0)
+ goto out_err;
+
+ ret = us5182d_read_word_data(data->client,
+ US5182D_REG_PDL);
+ if (ret < 0)
+ goto out_err;
+ mutex_unlock(&data->lock);
+ *val = ret;
+ *val2 = 0;
+ return IIO_VAL_INT;
+ default:
+ break;

return -EINVAL; directly
noted

+ }
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = us5182d_read_byte_data(data->client, US5182D_REG_CFG1);
+ if (ret < 0)
+ return ret;
+ *val = 0;
+ ret = (ret & US5182D_AGAIN_MASK);
+ *val2 = us5182d_scales[ret];
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+
+ return -EINVAL;
+out_err:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static int us5182d_update_dark_th(struct us5182d_data *data, int index)
+{
+ __be16 dark_th = cpu_to_be16(data->us5182d_dark_ths[index]);

really?
in us5182d_read_word_data() it appears that the sensor wants little endian
yes, unlike the others these are big endian.

+ u8 *bytes = (u8 *)&dark_th;
+ int ret;
+
+ /* Registers Dark_Th (0x27 0x28) don't work in word mode accessing */
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH,
+ bytes[0]);
+ if (ret < 0)
+ return ret;
+
+ return i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH + 1,
+ bytes[1]);
+}
+
+static int us5182d_apply_scale(struct us5182d_data *data, int index)
+{
+ int ret;
+
+ ret = us5182d_read_byte_data(data->client, US5182D_REG_CFG1);
+ if (ret < 0)
+ return ret;
+
+ ret = ret & (~US5182D_AGAIN_MASK);
+ ret |= index;
+
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG1, ret);
+ if (ret < 0)
+ return ret;
+
+ return us5182d_update_dark_th(data, index);
+}
+
+static int us5182d_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct us5182d_data *data = iio_priv(indio_dev);
+ int i;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ if (val != 0)
+ return -EINVAL;
+ for (i = 0; i < ARRAY_SIZE(us5182d_scales); i++)
+ if (val2 == us5182d_scales[i])
+ return us5182d_apply_scale(data, i);

I guess we want locking since two i2c operations are involved
good point

+ break;
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info us5182d_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = us5182d_read_raw,
+ .write_raw = us5182d_write_raw,
+ .attrs = &us5182d_attr_group,
+};
+
+static int us5182d_reset(struct iio_dev *indio_dev)
+{
+ struct us5182d_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG3,
+ US5182D_RESET_CHIP);

return i2c_smbus_write_byte_data(..);
directly

+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int us5182d_init(struct iio_dev *indio_dev)
+{
+ struct us5182d_data *data = iio_priv(indio_dev);
+ int i, ret;
+
+ ret = us5182d_reset(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ data->opmode = 0;
+ for (i = 0; i < ARRAY_SIZE(us5182d_regvals); i++) {
+ ret = i2c_smbus_write_byte_data(data->client,
+ us5182d_regvals[i].reg,
+ us5182d_regvals[i].val);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void us5182d_get_platform_data(struct iio_dev *indio_dev)
+{
+ struct us5182d_data *data = iio_priv(indio_dev);
+
+ if (device_property_read_u32(&data->client->dev, "upisemi,glass-coef",
+ &data->ga))
+ data->ga = US5182D_GA_RESOLUTION;
+ if (device_property_read_u16_array(&data->client->dev,
+ "upisemi,dark-ths",
+ data->us5182d_dark_ths,
+ ARRAY_SIZE(us5182d_dark_ths_vals)))
+ data->us5182d_dark_ths = us5182d_dark_ths_vals;
+ if (device_property_read_u16(&data->client->dev,
+ "upisemi,upper-dark-gain",
+ &data->upper_dark_th))
+ data->upper_dark_th = US5182D_REG_AUTO_HDARK_TH_DEFAULT;
+ if (device_property_read_u16(&data->client->dev,
+ "upisemi,lower-dark-gain",
+ &data->lower_dark_th))
+ data->lower_dark_th = US5182D_REG_AUTO_LDARK_TH_DEFAULT;
+}
+
+static int us5182d_dark_gain_config(struct iio_dev *indio_dev)
+{
+ struct us5182d_data *data = iio_priv(indio_dev);
+ u8 index = US5182D_REG_CFG1_DEFAULT & US5182D_AGAIN_MASK;
+ int ret;
+
+ ret = us5182d_update_dark_th(data, index);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_AUTO_LDARK_TH,
+ data->lower_dark_th);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_AUTO_HDARK_TH,
+ data->upper_dark_th);
+ if (ret < 0)
+ return ret;
+
+ return i2c_smbus_write_byte_data(data->client, US5182D_REG_DARK_AUTO_EN,
+ US5182D_REG_DARK_AUTO_EN_DEFAULT);
+}
+
+static int us5182d_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct us5182d_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+
+ mutex_init(&data->lock);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &us5182d_info;
+ indio_dev->name = US5182D_DRV_NAME;
+ indio_dev->channels = us5182d_channels;
+ indio_dev->num_channels = ARRAY_SIZE(us5182d_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = us5182d_read_byte_data(data->client, US5182D_REG_CHIPID);
+ if (ret != US5182D_CHIPID)
+ dev_warn(&data->client->dev,
+ "Failed to detect US5182 light chip\n");
+
+ us5182d_get_platform_data(indio_dev);
+ ret = us5182d_init(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ ret = us5182d_dark_gain_config(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ return iio_device_register(indio_dev);
+}
+
+static int us5182d_remove(struct i2c_client *client)
+{
+ iio_device_unregister(i2c_get_clientdata(client));
+ return i2c_smbus_write_byte_data(client, US5182D_REG_CFG0,
+ US5182D_REG_CFG0_DEFAULT);
+}
+
+static const struct acpi_device_id us5182d_acpi_match[] = {
+ { "USD5182", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, us5182d_acpi_match);
+
+static const struct i2c_device_id us5182d_id[] = {
+ {"usd5182", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, us5182d_id);
+
+static struct i2c_driver us5182d_driver = {
+ .driver = {
+ .name = US5182D_DRV_NAME,
+ .acpi_match_table = ACPI_PTR(us5182d_acpi_match),
+ },
+ .probe = us5182d_probe,
+ .remove = us5182d_remove,
+ .id_table = us5182d_id,
+
+};
+module_i2c_driver(us5182d_driver);
+
+MODULE_AUTHOR("Adriana Reus <adriana.reus@xxxxxxxxx>");
+MODULE_DESCRIPTION("Driver for us5182d Proximity and Light Sensor");
+MODULE_LICENSE("GPL v2");


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