Re: [PATCH v2] iio: light: Add support for UPISEMI uS5182d als and proximity sensor
From: Adriana Reus
Date: Fri Aug 14 2015 - 03:48:34 EST
Hi Jonathan,
Thanks for the review, I'll send out a new version soon.
Replies inline.
On 08.08.2015 17:54, Jonathan Cameron wrote:
On 04/08/15 14:40, 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
Signed-off-by: Adriana Reus <adriana.reus@xxxxxxxxx>
Device tree docs?
Adding soon.
Various other bits and bobs inline.
---
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
I'd prefer to see the elements of this register broken down. Something
like (guessing what is in this reg to a degree).
#define US5182D_REG_CFG0_DEFAULT \
(US5182D_AGAIN_1X | (US5182_OPMODE_ALS << US5182D_OPMODE_SHIFT))
Perhaps even define the inverse cases so that the values themselves act
as documentation. (so SHUTDOWN_DIS and ONESHOT_DIS)
Same is true for any of thes registers that are compound values.
Basically the code should be explicity where it can be rather than requiring
docs that don't make it obvious which parts of the value are the cause
of what.
OK, I'll try to break down the compound registers values.
+
+/*
+ * 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
+
Where these are fields in a particular register I'd
like to see the naming reflect that.
+#define US5182D_ONESHOT_EN_MASK BIT(6)
on this one, is it really a mask? Seems like a single
bit value so I'd drop the mask naming.
ok
#define US5182D_ONESHOT_EN 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
+#define READ_WORD 2
+#define OPSTORE_SLEEP_TIME 20 /* ms */
+
+/* available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux*/
+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,
+ 8000};
+
+enum mode {
+ ALS_PX,
+ 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 = ®
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = val
+ }
+ };
Close to an smbus_read_byte / word call, but that NOSTART is odd..
The docs state:
If you set the I2C_M_NOSTART variable for the first partial message,
we do not generate Addr, but we do generate the startbit S. This will
probably confuse all other clients on your bus, so don't try this.
So what is going on here?
I won't be needing that flag at all after-all. So all that construct
will go away and a straight i2c_smbus_read will do ok. I'm sorry for the
confusion, I was under the impression I need "no start" at direction
change (which would have been on the second partial message anyway) but
it seems there was some confusion in my communication with upi added
with some of my own misunderstanding. Sorry for that.
+
+ 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);
Just pass &val and don't have val as an array?
I wanted it to match the style of the "read_word" version. But it will
go away altogether anyway.
+ 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);
+ return (ret < 0) ? ret : (val[0] | (val[1] << 8));
I'd split this up and avoid the trinary operator as it makes
it harder to read.
+}
+
+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;
Should be no need to set val2 for a VAL_INT type (core won't touch it).
+ 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;
+ }
+
+ 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]);
+ 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);
+ 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);
+ 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;
No problem with these, but the need docs and those docs need a device
tree sign off (or a long period being ignored on their list)
+}
+
+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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