path: root/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/0051-TI-ADS111X-sigma-delta-ADC-driver.patch

From 623921d9a1815cb695b587088ea7909f2996b637 Mon Sep 17 00:00:00 2001
From: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
Date: Fri, 18 Sep 2015 16:19:57 +0300
Subject: [PATCH 51/52] TI ADS111X sigma-delta ADC driver


Signed-off-by: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
---
 drivers/iio/adc/Kconfig      |   10 ++
 drivers/iio/adc/Makefile     |    1 +
 drivers/iio/adc/ti-ads111x.c |  266 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 277 insertions(+)
 create mode 100644 drivers/iio/adc/ti-ads111x.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index ab0767e6..2ad9d87 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -143,6 +143,16 @@ config TI_ADC081C
 	  This driver can also be built as a module. If so, the module will be
 	  called ti-adc081c.

+config TI_ADS111X
+	tristate "Texas Instruments ADS1113/4/5"
+	depends on I2C
+	help
+	  If you say yes here you get support for Texas Instruments ADS1113/4/5
+	  sigma-delta ADC chips.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called ti-ads111x.
+
 config TI_AM335X_ADC
 	tristate "TI's ADC driver"
 	depends on MFD_TI_AM335X_TSCADC
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 0a825be..0a3c03f 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -15,5 +15,6 @@ obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
 obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
+obj-$(CONFIG_TI_ADS111X) += ti-ads111x.o
 obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
 obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o
diff --git a/drivers/iio/adc/ti-ads111x.c b/drivers/iio/adc/ti-ads111x.c
new file mode 100644
index 0000000..98a28e3e
--- /dev/null
+++ b/drivers/iio/adc/ti-ads111x.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright (C) 2015 CogentEmbedded Inc
+ *
+ * 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.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/regulator/consumer.h>
+
+#define REG_CONV_RES		0x00
+#define REG_CONFIG		0x01
+#define REG_LO_THRES		0x02
+#define REG_HI_THRES		0x03
+
+/* CONFIG reg bits */
+/* w: begin sigle conversion; r: operation status */
+#define CONFIG_OS		(1 << 15)
+#define CONFIG_CH(n)		(n << 12)
+/* ADS1114/5 only */
+#define CONFIG_PGA_6144		(0 << 9)
+#define CONFIG_PGA_4096		(1 << 9)
+#define CONFIG_PGA_2048		(2 << 9)	/* def */
+#define CONFIG_PGA_1024		(3 << 9)
+#define CONFIG_PGA_0512		(4 << 9)
+#define CONFIG_PGA_0256		(5 << 9)
+#define CONFIG_MODE_CONT	(0 << 8)
+#define CONFIG_MODE_SINGLE	(1 << 8)
+#define CONFIG_DR_8SPS		(0 << 5)
+#define CONFIG_DR_16SPS		(1 << 5)
+#define CONFIG_DR_32SPS		(2 << 5)
+#define CONFIG_DR_64SPS		(3 << 5)
+#define CONFIG_DR_128SPS	(4 << 5)
+#define CONFIG_DR_250SPS	(5 << 5)
+#define CONFIG_DR_475SPS	(6 << 5)
+#define CONFIG_DR_860SPS	(7 << 5)
+/* ADS1114/5 only */
+#define CONFIG_COMP_HYST	(0 << 4)
+#define CONFIG_COMP_WINDOW	(1 << 4)
+#define CONFIG_COMP_POL_LOW	(0 << 3)
+#define CONFIG_COMP_POL_HIGH	(1 << 3)
+#define CONFIG_COMP_NONLATCH	(0 << 2)
+#define CONFIG_COMP_LATCH	(1 << 2)
+#define CONFIG_COMP_QUE_1	(0 << 0)
+#define CONFIG_COMP_QUE_2	(1 << 0)
+#define CONFIG_COMP_QUE_4	(2 << 0)
+#define CONFIG_COMP_QUE_DIS	(3 << 0)
+
+struct ads111x {
+	struct i2c_client *i2c;
+	int type;
+};
+
+enum ads111x_types {
+	ads1113,
+	ads1114,
+	ads1115,
+};
+
+/* Applies to ads1115 */
+enum ads1115_modes {
+	p0n1, p0n3, p1n3, p2n3,
+	p0, p1, p2, p3
+};
+
+/* unipolar channel */
+#define ADS1115_CHAN_U(num, addr)					\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.indexed = 1,						\
+		.channel = num,						\
+		.address = addr,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.datasheet_name = "AIN"#num,				\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 16,					\
+			.storagebits = 16,				\
+			.endianness = IIO_BE,				\
+		},							\
+	}
+
+/* bipolar channel */
+#define ADS111X_CHAN_B(num, num2, addr)					\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.differential = 1,					\
+		.indexed = 1,						\
+		.channel = num,						\
+		.channel2 = num2,					\
+		.address = addr,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.datasheet_name = "AIN"#num"-AIN"#num2,			\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 16,					\
+			.storagebits = 16,				\
+			.endianness = IIO_BE,				\
+		},							\
+	}
+
+static const struct iio_chan_spec ads111x_channels[] = {
+	/* ADS1113/4/5 */
+	ADS111X_CHAN_B(0, 1, p0n1),
+	/* ADS1115 only */
+	ADS111X_CHAN_B(0, 3, p0n3),
+	ADS111X_CHAN_B(1, 3, p1n3),
+	ADS111X_CHAN_B(2, 3, p2n3),
+	ADS1115_CHAN_U(0, p0),
+	ADS1115_CHAN_U(1, p1),
+	ADS1115_CHAN_U(2, p2),
+	ADS1115_CHAN_U(3, p3),
+};
+
+static int ads111x_read_raw(struct iio_dev *iio,
+			    struct iio_chan_spec const *channel, int *value,
+			    int *shift, long mask)
+{
+	struct ads111x *adc = iio_priv(iio);
+	u16 config_reg;
+	int err;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		config_reg =
+			CONFIG_OS |
+			CONFIG_CH(channel->address) |
+			CONFIG_PGA_2048 |
+			CONFIG_MODE_SINGLE |
+			CONFIG_DR_860SPS |
+			CONFIG_COMP_QUE_DIS;
+		err = i2c_smbus_write_word_swapped(adc->i2c, REG_CONFIG, config_reg);
+		if (err < 0) {
+			dev_err(&iio->dev, "REG_CONFIG write err %d\n", err);
+			return err;
+		}
+		mdelay(1);
+		err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONFIG);
+		if (err < 0) {
+			dev_err(&iio->dev, "REG_CONFIG read err %d\n", err);
+			return err;
+		}
+		if (err & CONFIG_OS) {
+			dev_err(&iio->dev, "ADC not ready 0x%04x\n", err);
+			return -EBUSY;
+		}
+		err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
+		if (err < 0) {
+			dev_err(&iio->dev, "REG_CONV_RES read err %d\n", err);
+			return err;
+		}
+
+		*value = err;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*value =  2048000;
+		*shift = 0;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info ads111x_info = {
+	.read_raw = ads111x_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int ads111x_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct iio_dev *iio;
+	struct ads111x *adc;
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	iio = iio_device_alloc(sizeof(*adc));
+	if (!iio)
+		return -ENOMEM;
+
+	adc = iio_priv(iio);
+	adc->i2c = client;
+	adc->type = id->driver_data;
+
+	iio->dev.parent = &client->dev;
+	iio->name = dev_name(&client->dev);
+	iio->modes = INDIO_DIRECT_MODE;
+	iio->info = &ads111x_info;
+
+	iio->channels = ads111x_channels;
+	if (id->driver_data == ads1115)
+		iio->num_channels = ARRAY_SIZE(ads111x_channels);
+	else
+		iio->num_channels = 1;
+
+	err = iio_device_register(iio);
+	if (err < 0)
+		goto iio_free;
+
+	i2c_set_clientdata(client, iio);
+
+	return 0;
+
+iio_free:
+	iio_device_free(iio);
+
+	return err;
+}
+
+static int ads111x_remove(struct i2c_client *client)
+{
+	struct iio_dev *iio = i2c_get_clientdata(client);
+
+	iio_device_unregister(iio);
+	iio_device_free(iio);
+
+	return 0;
+}
+
+static const struct i2c_device_id ads111x_id[] = {
+	{ "ads1113", ads1113 },
+	{ "ads1114", ads1114 },
+	{ "ads1115", ads1115 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ads111x_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id ads111x_of_match[] = {
+	{ .compatible = "ti,ads1113" },
+	{ .compatible = "ti,ads1114" },
+	{ .compatible = "ti,ads1115" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ads111x_of_match);
+#endif
+
+static struct i2c_driver ads111x_driver = {
+	.driver = {
+		.name = "ads111x",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(ads111x_of_match),
+	},
+	.probe = ads111x_probe,
+	.remove = ads111x_remove,
+	.id_table = ads111x_id,
+};
+module_i2c_driver(ads111x_driver);
+
+MODULE_AUTHOR("Andrey Gusakov <andrey.gusakov@cogentembedded.com");
+MODULE_DESCRIPTION("Texas Instruments ADS1113/4/5 driver");
+MODULE_LICENSE("GPL v2");
--
1.7.10.4