Re: [PATCH v8 3/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature
From: Jonathan Cameron
Date: Thu Nov 24 2016 - 12:38:21 EST
On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@xxxxxxxxxxxxx> wrote:
>The tsc2007 chip not only has a resistive touch screen controller but
>also an external AUX adc imput which can be used for an ambient
>light sensor, battery voltage monitoring or any general purpose.
>
>Additionally it can measure the chip temperature.
>
>This extension provides an iio interface for these adc channels.
>
>Since it is not wasting much resources and is very straightforward,
>we simply provide all other adc channels as optional iio interfaces
>as weel. This can be used for debugging or special applications.
>
>This patch also splits the tsc2007 driver in several source files:
>tsc2007.h -- constants, structs and stubs
>tsc2007_core.c -- functional parts of the original driver
>tsc2007_iio.c -- the optional iio stuff
>
>Makefile magic allows to conditionally link the iio stuff
>if CONFIG_IIO=y or =m in a way that it works with
>CONFIG_TOUCHSCREEN_TSC2007=m.
>
>Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
>Reviewed-by: Jonathan Cameron <jic23@xxxxxxxxxx>
>---
> drivers/input/touchscreen/Makefile | 7 +
>drivers/input/touchscreen/tsc2007.h | 116
>++++++++++++++++
> .../touchscreen/{tsc2007.c => tsc2007_core.c} | 95 +++----------
>drivers/input/touchscreen/tsc2007_iio.c | 150
>+++++++++++++++++++++
> 4 files changed, 294 insertions(+), 74 deletions(-)
> create mode 100644 drivers/input/touchscreen/tsc2007.h
> rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
> create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
>
>diff --git a/drivers/input/touchscreen/Makefile
>b/drivers/input/touchscreen/Makefile
>index 81b8645..3be0d19 100644
>--- a/drivers/input/touchscreen/Makefile
>+++ b/drivers/input/touchscreen/Makefile
>@@ -80,6 +80,13 @@ obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO) += tsc40.o
> obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE) += tsc200x-core.o
> obj-$(CONFIG_TOUCHSCREEN_TSC2004) += tsc2004.o
> obj-$(CONFIG_TOUCHSCREEN_TSC2005) += tsc2005.o
>+tsc2007-y := tsc2007_core.o
>+ifeq ($(CONFIG_IIO),y)
>+tsc2007-y += tsc2007_iio.o
>+endif
>+ifeq ($(CONFIG_IIO),m)
>+tsc2007-y += tsc2007_iio.o
Not tsc2007-m ?
I don't follow how this works!
>+endif
> obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
> obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o
> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001) += wacom_w8001.o
>diff --git a/drivers/input/touchscreen/tsc2007.h
>b/drivers/input/touchscreen/tsc2007.h
>new file mode 100644
>index 0000000..c25932f
>--- /dev/null
>+++ b/drivers/input/touchscreen/tsc2007.h
>@@ -0,0 +1,116 @@
>+/*
>+ * Copyright (c) 2008 MtekVision Co., Ltd.
>+ * Kwangwoo Lee <kwlee@xxxxxxxxxxxxxx>
>+ *
>+ * Using code from:
>+ * - ads7846.c
>+ * Copyright (c) 2005 David Brownell
>+ * Copyright (c) 2006 Nokia Corporation
>+ * - corgi_ts.c
>+ * Copyright (C) 2004-2005 Richard Purdie
>+ * - omap_ts.[hc], ads7846.h, ts_osk.c
>+ * Copyright (C) 2002 MontaVista Software
>+ * Copyright (C) 2004 Texas Instruments
>+ * Copyright (C) 2005 Dirk Behme
>+ *
>+ * 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/input/touchscreen.h>
>+
>+#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
>+#define TSC2007_MEASURE_AUX (0x2 << 4)
>+#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
>+#define TSC2007_ACTIVATE_XN (0x8 << 4)
>+#define TSC2007_ACTIVATE_YN (0x9 << 4)
>+#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
>+#define TSC2007_SETUP (0xb << 4)
>+#define TSC2007_MEASURE_X (0xc << 4)
>+#define TSC2007_MEASURE_Y (0xd << 4)
>+#define TSC2007_MEASURE_Z1 (0xe << 4)
>+#define TSC2007_MEASURE_Z2 (0xf << 4)
>+
>+#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
>+#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
>+#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
>+#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
>+
>+#define TSC2007_12BIT (0x0 << 1)
>+#define TSC2007_8BIT (0x1 << 1)
>+
>+#define MAX_12BIT ((1 << 12) - 1)
>+
>+#define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>+
>+#define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
>+#define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>+#define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>+#define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
>+#define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>+
>+struct ts_event {
>+ u16 x;
>+ u16 y;
>+ u16 z1, z2;
>+};
>+
>+struct tsc2007 {
>+ struct input_dev *input;
>+ char phys[32];
>+
>+ struct i2c_client *client;
>+
>+ u16 model;
>+ u16 x_plate_ohms;
>+
>+ struct touchscreen_properties prop;
>+
>+ bool report_resistance;
>+ u16 min_x;
>+ u16 min_y;
>+ u16 max_x;
>+ u16 max_y;
>+ u16 max_rt;
>+ unsigned long poll_period; /* in jiffies */
>+ int fuzzx;
>+ int fuzzy;
>+ int fuzzz;
>+
>+ unsigned int gpio;
>+ int irq;
>+
>+ wait_queue_head_t wait;
>+ bool stopped;
>+ bool pendown;
>+
>+ int (*get_pendown_state)(struct device *);
>+ void (*clear_penirq)(void);
>+
>+ struct mutex mlock;
>+ struct iio_dev *iio_dev; /* optional */
>+};
>+
>+int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
>+u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>+ struct ts_event *tc);
>+bool tsc2007_is_pen_down(struct tsc2007 *ts);
>+
>+#if IS_ENABLED(CONFIG_IIO)
>+
>+/* defined in tsc2007_iio.c */
>+int tsc2007_iio_configure(struct tsc2007 *ts);
>+void tsc2007_iio_unconfigure(struct tsc2007 *ts);
>+
>+#else /* CONFIG_IIO */
>+
>+static inline int tsc2007_iio_configure(struct tsc2007 *ts)
>+{
>+ return 0;
>+}
>+static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>+{
>+}
>+
>+#endif /* CONFIG_IIO */
>diff --git a/drivers/input/touchscreen/tsc2007.c
>b/drivers/input/touchscreen/tsc2007_core.c
>similarity index 86%
>rename from drivers/input/touchscreen/tsc2007.c
>rename to drivers/input/touchscreen/tsc2007_core.c
>index 76b462b..812ded8 100644
>--- a/drivers/input/touchscreen/tsc2007.c
>+++ b/drivers/input/touchscreen/tsc2007_core.c
>@@ -27,79 +27,11 @@
> #include <linux/i2c.h>
> #include <linux/i2c/tsc2007.h>
> #include <linux/of_device.h>
>-#include <linux/of.h>
> #include <linux/of_gpio.h>
>-#include <linux/input/touchscreen.h>
>-
>-#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
>-#define TSC2007_MEASURE_AUX (0x2 << 4)
>-#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
>-#define TSC2007_ACTIVATE_XN (0x8 << 4)
>-#define TSC2007_ACTIVATE_YN (0x9 << 4)
>-#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
>-#define TSC2007_SETUP (0xb << 4)
>-#define TSC2007_MEASURE_X (0xc << 4)
>-#define TSC2007_MEASURE_Y (0xd << 4)
>-#define TSC2007_MEASURE_Z1 (0xe << 4)
>-#define TSC2007_MEASURE_Z2 (0xf << 4)
>-
>-#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
>-#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
>-#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
>-#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
>-
>-#define TSC2007_12BIT (0x0 << 1)
>-#define TSC2007_8BIT (0x1 << 1)
>-
>-#define MAX_12BIT ((1 << 12) - 1)
>-
>-#define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>-
>-#define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
>-#define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>-#define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>-#define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
>-#define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>-
>-struct ts_event {
>- u16 x;
>- u16 y;
>- u16 z1, z2;
>-};
>-
>-struct tsc2007 {
>- struct input_dev *input;
>- char phys[32];
>-
>- struct i2c_client *client;
>-
>- u16 model;
>- u16 x_plate_ohms;
>-
>- struct touchscreen_properties prop;
>-
>- bool report_resistance;
>- u16 min_x;
>- u16 min_y;
>- u16 max_x;
>- u16 max_y;
>- u16 max_rt;
>- unsigned long poll_period; /* in jiffies */
>- int fuzzx;
>- int fuzzy;
>- int fuzzz;
>-
>- unsigned gpio;
>- int irq;
>-
>- wait_queue_head_t wait;
>- bool stopped;
>+#include "tsc2007.h"
>
>- int (*get_pendown_state)(struct device *);
>- void (*clear_penirq)(void);
>-};
>
>-static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>+int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
> {
> s32 data;
> u16 val;
>@@ -137,7 +69,7 @@ static void tsc2007_read_values(struct tsc2007 *tsc,
>struct ts_event *tc)
> tsc2007_xfer(tsc, PWRDOWN);
> }
>
>-static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>+u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
> struct ts_event *tc)
> {
> u32 rt = 0;
>@@ -158,7 +90,7 @@ static u32 tsc2007_calculate_resistance(struct
>tsc2007 *tsc,
> return rt;
> }
>
>-static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>+bool tsc2007_is_pen_down(struct tsc2007 *ts)
> {
> /*
> * NOTE: We can't rely on the pressure to determine the pen down
>@@ -191,7 +123,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void
>*handle)
> while (!ts->stopped && tsc2007_is_pen_down(ts)) {
>
> /* pen is down, continue with the measurement */
>+
>+ mutex_lock(&ts->mlock);
> tsc2007_read_values(ts, &tc);
>+ mutex_unlock(&ts->mlock);
>
> rt = tsc2007_calculate_resistance(ts, &tc);
>
>@@ -441,7 +376,8 @@ static void tsc2007_call_exit_platform_hw(void
>*data)
> static int tsc2007_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
>- const struct tsc2007_platform_data *pdata =
>dev_get_platdata(&client->dev);
>+ const struct tsc2007_platform_data *pdata =
>+ dev_get_platdata(&client->dev);
> struct tsc2007 *ts;
> struct input_dev *input_dev;
> int err;
>@@ -463,7 +399,9 @@ static int tsc2007_probe(struct i2c_client *client,
> ts->client = client;
> ts->irq = client->irq;
> ts->input = input_dev;
>+
> init_waitqueue_head(&ts->wait);
>+ mutex_init(&ts->mlock);
>
> snprintf(ts->phys, sizeof(ts->phys),
> "%s/input0", dev_name(&client->dev));
>@@ -534,7 +472,7 @@ static int tsc2007_probe(struct i2c_client *client,
> if (err < 0) {
> dev_err(&client->dev,
> "Failed to setup chip: %d\n", err);
>- return err; /* usually, chip does not respond */
>+ return err; /* chip does not respond */
> }
>
> err = input_register_device(input_dev);
>@@ -544,6 +482,14 @@ static int tsc2007_probe(struct i2c_client
>*client,
> return err;
> }
>
>+ return tsc2007_iio_configure(ts);
>+}
>+
>+static int tsc2007_remove(struct i2c_client *client)
>+{
>+ struct tsc2007 *ts = i2c_get_clientdata(client);
>+
>+ tsc2007_iio_unconfigure(ts);
> return 0;
> }
>
>@@ -569,6 +515,7 @@ static struct i2c_driver tsc2007_driver = {
> },
> .id_table = tsc2007_idtable,
> .probe = tsc2007_probe,
>+ .remove = tsc2007_remove,
> };
>
> module_i2c_driver(tsc2007_driver);
>diff --git a/drivers/input/touchscreen/tsc2007_iio.c
>b/drivers/input/touchscreen/tsc2007_iio.c
>new file mode 100644
>index 0000000..ed79944
>--- /dev/null
>+++ b/drivers/input/touchscreen/tsc2007_iio.c
>@@ -0,0 +1,150 @@
>+/*
>+ * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
>+ * Nikolaus Schaller <hns@xxxxxxxxxxxxx>
>+ *
>+ * 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/i2c.h>
>+#include <linux/iio/iio.h>
>+#include "tsc2007.h"
>+
>+struct tsc2007_iio {
>+ struct tsc2007 *ts;
>+};
>+
>+#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
>+{ \
>+ .datasheet_name = _name, \
>+ .type = _type, \
>+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
>+ BIT(_chan_info), \
>+ .indexed = 1, \
>+ .channel = _chan, \
>+}
>+
>+static const struct iio_chan_spec tsc2007_iio_channel[] = {
>+ TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms?
>*/
>+ TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
>+ TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
>+};
>+
>+static int tsc2007_read_raw(struct iio_dev *indio_dev,
>+ struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>+{
>+ struct tsc2007_iio *iio = iio_priv(indio_dev);
>+ struct tsc2007 *tsc = iio->ts;
>+ int adc_chan = chan->channel;
>+ int ret = 0;
>+
>+ if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
>+ return -EINVAL;
>+
>+ if (mask != IIO_CHAN_INFO_RAW)
>+ return -EINVAL;
>+
>+ mutex_lock(&tsc->mlock);
>+
>+ switch (chan->channel) {
>+ case 0:
>+ *val = tsc2007_xfer(tsc, READ_X);
>+ break;
>+ case 1:
>+ *val = tsc2007_xfer(tsc, READ_Y);
>+ break;
>+ case 2:
>+ *val = tsc2007_xfer(tsc, READ_Z1);
>+ break;
>+ case 3:
>+ *val = tsc2007_xfer(tsc, READ_Z2);
>+ break;
>+ case 4:
>+ *val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
>+ break;
>+ case 5: {
>+ struct ts_event tc;
>+
>+ tc.x = tsc2007_xfer(tsc, READ_X);
>+ tc.z1 = tsc2007_xfer(tsc, READ_Z1);
>+ tc.z2 = tsc2007_xfer(tsc, READ_Z2);
>+ *val = tsc2007_calculate_resistance(tsc, &tc);
>+ break;
>+ }
>+ case 6:
>+ *val = tsc2007_is_pen_down(tsc);
>+ break;
>+ case 7:
>+ *val = tsc2007_xfer(tsc,
>+ (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
>+ break;
>+ case 8:
>+ *val = tsc2007_xfer(tsc,
>+ (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
>+ break;
>+ }
>+
>+ /* Prepare for next touch reading - power down ADC, enable PENIRQ */
>+ tsc2007_xfer(tsc, PWRDOWN);
>+
>+ mutex_unlock(&tsc->mlock);
>+
>+ ret = IIO_VAL_INT;
>+
>+ return ret;
>+}
>+
>+static const struct iio_info tsc2007_iio_info = {
>+ .read_raw = tsc2007_read_raw,
>+ .driver_module = THIS_MODULE,
>+};
>+
>+int tsc2007_iio_configure(struct tsc2007 *ts)
>+{
>+ int err;
>+ struct iio_dev *indio_dev;
>+ struct tsc2007_iio *iio;
>+
>+ indio_dev = devm_iio_device_alloc(&ts->client->dev,
>+ sizeof(struct tsc2007_iio));
>+ if (!indio_dev) {
>+ dev_err(&ts->client->dev, "iio_device_alloc failed\n");
>+ return -ENOMEM;
>+ }
>+
>+ iio = iio_priv(indio_dev);
>+ iio->ts = ts;
>+ ts->iio_dev = (void *) indio_dev;
>+
>+ indio_dev->name = "tsc2007";
>+ indio_dev->dev.parent = &ts->client->dev;
>+ indio_dev->info = &tsc2007_iio_info;
>+ indio_dev->modes = INDIO_DIRECT_MODE;
>+ indio_dev->channels = tsc2007_iio_channel;
>+ indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
>+
>+ err = iio_device_register(indio_dev);
>+ if (err < 0) {
>+ dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
>+ err);
>+ return err;
>+ }
>+
>+ return 0;
>+}
>+EXPORT_SYMBOL(tsc2007_iio_configure);
>+
>+void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>+{
>+ struct iio_dev *indio_dev = ts->iio_dev;
>+
>+ iio_device_unregister(indio_dev);
>+}
>+EXPORT_SYMBOL(tsc2007_iio_unconfigure);
--
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