From: Stefan Agner <stefan@xxxxxxxx>
This adds an ADC driver for the STMPE device using the industrial
input/output interface. The driver supports raw reading of values.
The driver depends on the MFD STMPE driver. If the touchscreen
block is enabled too, only four of the 8 ADC channels are available.
Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
Signed-off-by: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>
Signed-off-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
---
drivers/iio/adc/Kconfig | 7 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/stmpe-adc.c | 383 +++++++++++++++++++++++++++
drivers/input/touchscreen/stmpe-ts.c | 11 -
drivers/mfd/Kconfig | 3 +-
drivers/mfd/stmpe.c | 27 ++
include/linux/mfd/stmpe.h | 11 +
7 files changed, 431 insertions(+), 12 deletions(-)
create mode 100644 drivers/iio/adc/stmpe-adc.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index a52fea8749a9..d2845472b6c2 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -734,6 +734,13 @@ config STM32_DFSDM_ADC
This driver can also be built as a module. If so, the module
will be called stm32-dfsdm-adc.
+config STMPE_ADC
+ tristate "STMicroelectronics STMPE ADC driver"
+ depends on (OF || COMPILE_TEST || MFD_STMPE)
+ help
+ Say yes here to build support for ST Microelectronics STMPE
+ built in ADC block (stmpe811).
+
config STX104
tristate "Apex Embedded Systems STX104 driver"
depends on PC104 && X86
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index a6e6a0b659e2..cba889c30bf9 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
obj-$(CONFIG_STM32_ADC) += stm32-adc.o
obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o
obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o
+obj-$(CONFIG_STMPE_ADC) += stmpe-adc.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
new file mode 100644
index 000000000000..891ad838ab3c
--- /dev/null
+++ b/drivers/iio/adc/stmpe-adc.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * STMicroelectronics STMPE811 IIO ADC Driver
+ *
+ * 4 channel, 10/12-bit ADC
+ *
+ * Copyright (C) 2013-2018 Toradex AG <stefan.agner@xxxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/stmpe.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define STMPE_REG_INT_STA 0x0B
+#define STMPE_REG_ADC_INT_EN 0x0E
+#define STMPE_REG_ADC_INT_STA 0x0F
+
+#define STMPE_REG_ADC_CTRL1 0x20
+#define STMPE_REG_ADC_CTRL2 0x21
+#define STMPE_REG_ADC_CAPT 0x22
+#define STMPE_REG_ADC_DATA_CH(channel) (0x30 + 2 * (channel))
+
+#define STMPE_REG_TEMP_CTRL 0x60
+#define STMPE_START_ONE_TEMP_CONV (0x08 + 0x02 + 0x01)
+#define STMPE_REG_TEMP_DATA 0x61
+#define STMPE_REG_TEMP_TH 0x63
+#define STMPE_MAX_ADC_CH 8
+
+#define STMPE_ADC_CH(channel) ((1 << (channel)) & 0xff)
+
+#define STMPE_ADC_TIMEOUT (msecs_to_jiffies(1000))
+
+struct stmpe_adc {
+ struct stmpe *stmpe;
+ struct clk *clk;
+ struct device *dev;
+
+ struct iio_chan_spec stmpe_adc_iio_channels[STMPE_MAX_ADC_CH];
+
+ struct completion completion;
+
+ u8 channel;
+ u32 value;
+ u8 sample_time;
+ u8 mod_12b;
+ u8 ref_sel;
+ u8 adc_freq;
+ u32 norequest_mask;
+};
+
+static int stmpe_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long mask)
+{
+ struct stmpe_adc *info = iio_priv(indio_dev);
+ long ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ case IIO_CHAN_INFO_PROCESSED:
+
+ mutex_lock(&indio_dev->mlock);
+
+ info->channel = (u8)chan->channel;
+
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ if (info->channel > 7)
+ return -ENOENT;
+
+ stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_EN,
+ STMPE_ADC_CH(info->channel));
+
+ stmpe_reg_write(info->stmpe, STMPE_REG_ADC_CAPT,
+ STMPE_ADC_CH(info->channel));
+
+ *val = info->value;
+ break;
+
+ case IIO_TEMP:
+ if (info->channel != 8)
+ return -ENOENT;
+
+ stmpe_reg_write(info->stmpe, STMPE_REG_TEMP_CTRL,
+ STMPE_START_ONE_TEMP_CONV);
+ break;
+ default:
+ mutex_unlock(&indio_dev->mlock);
+ return -EINVAL;
+ }
+
+ ret = wait_for_completion_interruptible_timeout
+ (&info->completion, STMPE_ADC_TIMEOUT);
+
+ if (ret <= 0) {
+ mutex_unlock(&indio_dev->mlock);
+ if (ret == 0)
+ return -ETIMEDOUT;
+ else
+ return ret;
+ }
+
+
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ *val = info->value;
+ break;
+
+ case IIO_TEMP:
+ /*
+ * absolute temp = +V3.3 * value /7.51 [K]
+ * scale to [milli °C]
+ */
+ *val = ((449960l * info->value) / 1024l) - 273150;
+ break;
+ default:
+ break;
+ }
+
+ mutex_unlock(&indio_dev->mlock);
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = 3300;
+ *val2 = info->mod_12b ? 12 : 10;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static irqreturn_t stmpe_adc_isr(int irq, void *dev_id)
+{
+ struct stmpe_adc *info = (struct stmpe_adc *)dev_id;
+ u8 data[2];
+
+ if (info->channel > 8)
+ return IRQ_NONE;
+
+ if (info->channel < 8) {
+ int int_sta;
+
+ int_sta = stmpe_reg_read(info->stmpe, STMPE_REG_ADC_INT_STA);
+
+ /* Is the interrupt relevant */
+ if (!(int_sta & STMPE_ADC_CH(info->channel)))
+ return IRQ_NONE;
+
+ /* Read value */
+ stmpe_block_read(info->stmpe,
+ STMPE_REG_ADC_DATA_CH(info->channel), 2, data);
+
+ stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA, int_sta);
+ } else if (info->channel == 8) {
+ /* Read value */
+ stmpe_block_read(info->stmpe, STMPE_REG_TEMP_DATA, 2, data);
+ }
+
+ info->value = ((u32)data[0] << 8) + data[1];
+ complete(&info->completion);
+
+ return IRQ_HANDLED;
+}
+
+static const struct iio_info stmpe_adc_iio_info = {
+ .read_raw = &stmpe_read_raw,
+};
+
+static void stmpe_adc_voltage_chan(struct iio_chan_spec *ics, int chan)
+{
+ ics->type = IIO_VOLTAGE;
+ ics->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ ics->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
+ ics->indexed = 1;
+ ics->channel = chan;
+}
+
+static void stmpe_adc_temp_chan(struct iio_chan_spec *ics, int chan)
+{
+ ics->type = IIO_TEMP;
+ ics->info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED);
+ ics->indexed = 1;
+ ics->channel = chan;
+}
+
+static int stmpe_adc_init_hw(struct stmpe_adc *adc)
+{
+ int ret;
+ u8 adc_ctrl1, adc_ctrl1_mask;
+ struct stmpe *stmpe = adc->stmpe;
+ struct device *dev = adc->dev;
+
+ ret = stmpe_enable(stmpe, STMPE_BLOCK_ADC);
+ if (ret) {
+ dev_err(dev, "Could not enable clock for ADC\n");
+ goto err_adc;
+ }
+
+ adc_ctrl1 = SAMPLE_TIME(adc->sample_time) | MOD_12B(adc->mod_12b) |
+ REF_SEL(adc->ref_sel);
+ adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
+ adc_ctrl1_mask, adc_ctrl1);
+ if (ret) {
+ dev_err(dev, "Could not setup ADC\n");
+ goto err_adc;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
+ ADC_FREQ(0xff), ADC_FREQ(adc->adc_freq));
+ if (ret) {
+ dev_err(dev, "Could not setup ADC\n");
+ goto err_adc;
+ }
+
+ /* use temp irq for each conversion completion */
+ stmpe_reg_write(stmpe, STMPE_REG_TEMP_TH, 0);
+ stmpe_reg_write(stmpe, STMPE_REG_TEMP_TH + 1, 0);
+
+ return 0;
+err_adc:
+ stmpe_disable(stmpe, STMPE_BLOCK_ADC);
+
+ return ret;
+}
+
+static void stmpe_adc_get_platform_info(struct platform_device *pdev,
+ struct stmpe_adc *adc)
+{
+ struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+ struct device_node *np = pdev->dev.of_node;
+ u32 val;
+
+ adc->stmpe = stmpe;
+
+ if (!np) {
+ dev_err(&pdev->dev, "no device tree node found\n");
+ return;
+ }
+
+ if (!of_property_read_u32(np, "st,sample-time", &val))
+ adc->sample_time = val;
+ if (!of_property_read_u32(np, "st,mod-12b", &val))
+ adc->mod_12b = val;
+ if (!of_property_read_u32(np, "st,ref-sel", &val))
+ adc->ref_sel = val;
+ if (!of_property_read_u32(np, "st,adc-freq", &val))
+ adc->adc_freq = val;
+ if (!of_property_read_u32(np, "st,norequest-mask", &val))
+ adc->norequest_mask = val;
+}
+
+static int stmpe_adc_probe(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = NULL;
+ struct stmpe_adc *info = NULL;
+ int irq_temp, irq_adc;
+ int num_chan = 0;
+ int i = 0;
+ int ret;
+
+ irq_adc = platform_get_irq_byname(pdev, "STMPE_ADC");
+ if (irq_adc < 0)
+ return irq_adc;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct stmpe_adc));
+ if (!indio_dev) {
+ dev_err(&pdev->dev, "failed allocating iio device\n");
+ return -ENOMEM;
+ }
+
+ info = iio_priv(indio_dev);
+
+ init_completion(&info->completion);
+ ret = devm_request_threaded_irq(&pdev->dev, irq_adc, NULL,
+ stmpe_adc_isr, IRQF_ONESHOT,
+ "stmpe-adc", info);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
+ irq_adc);
+ return ret;
+ }
+
+ irq_temp = platform_get_irq_byname(pdev, "STMPE_TEMP_SENS");
+ if (irq_temp >= 0) {
+ ret = devm_request_threaded_irq(&pdev->dev, irq_temp, NULL,
+ stmpe_adc_isr, IRQF_ONESHOT,
+ "stmpe-adc", info);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "failed requesting irq for"
+ " temp sensor, irq = %d\n", irq_temp);
+ }
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ indio_dev->name = dev_name(&pdev->dev);
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->info = &stmpe_adc_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ stmpe_adc_get_platform_info(pdev, info);
+
+ for_each_clear_bit(i, (unsigned long *) &info->norequest_mask,
+ STMPE_MAX_ADC_CH) {
+ stmpe_adc_voltage_chan(&info->stmpe_adc_iio_channels[num_chan], i);
+ num_chan++;
+ }
+ stmpe_adc_temp_chan(&info->stmpe_adc_iio_channels[num_chan], i);
+ num_chan++;
+ indio_dev->channels = info->stmpe_adc_iio_channels;
+ indio_dev->num_channels = num_chan;
+
+ ret = stmpe_adc_init_hw(info);
+ if (ret)
+ return ret;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ return ret;
+
+
+ dev_info(&pdev->dev, "Initialized\n");
+
+ return 0;
+}
+
+static int stmpe_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct stmpe_adc *info = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ stmpe_disable(info->stmpe, STMPE_BLOCK_ADC);
+
+ return 0;
+}
+
+static int __maybe_unused stmpe_adc_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct stmpe_adc *info = iio_priv(indio_dev);
+
+ stmpe_adc_init_hw(info);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(stmpe_adc_pm_ops, NULL, stmpe_adc_resume);
+
+static struct platform_driver stmpe_adc_driver = {
+ .probe = stmpe_adc_probe,
+ .remove = stmpe_adc_remove,
+ .driver = {
+ .name = "stmpe-adc",
+ .pm = &stmpe_adc_pm_ops,
+ },
+};
+
+module_platform_driver(stmpe_adc_driver);
+
+MODULE_AUTHOR("Stefan Agner <stefan.agner@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("STMPEXXX ADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:stmpe-adc");
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
index 2a78e27b4495..05674e0e233f 100644
--- a/drivers/input/touchscreen/stmpe-ts.c
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -49,17 +49,6 @@
#define STMPE_IRQ_TOUCH_DET 0
-#define SAMPLE_TIME(x) ((x & 0xf) << 4)
-#define MOD_12B(x) ((x & 0x1) << 3)
-#define REF_SEL(x) ((x & 0x1) << 1)
-#define ADC_FREQ(x) (x & 0x3)
-#define AVE_CTRL(x) ((x & 0x3) << 6)
-#define DET_DELAY(x) ((x & 0x7) << 3)
-#define SETTLING(x) (x & 0x7)
-#define FRACTION_Z(x) (x & 0x7)
-#define I_DRIVE(x) (x & 0x1)
-#define OP_MODE(x) ((x & 0x7) << 1)
-
#define STMPE_TS_NAME "stmpe-ts"
#define XY_MASK 0xfff
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 8c5dfdce4326..bba159e8eaa4 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1204,7 +1204,7 @@ config MFD_STMPE
Currently supported devices are:
- STMPE811: GPIO, Touchscreen
+ STMPE811: GPIO, Touchscreen, ADC
STMPE1601: GPIO, Keypad
STMPE1801: GPIO, Keypad
STMPE2401: GPIO, Keypad
@@ -1217,6 +1217,7 @@ config MFD_STMPE
GPIO: stmpe-gpio
Keypad: stmpe-keypad
Touchscreen: stmpe-ts
+ ADC: stmpe-adc
menu "STMicroelectronics STMPE Interface Drivers"
depends on MFD_STMPE
diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index 566caca4efd8..00b98f75f7dd 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -463,6 +463,28 @@ static const struct mfd_cell stmpe_ts_cell = {
.num_resources = ARRAY_SIZE(stmpe_ts_resources),
};
+/*
+ * ADC (STMPE811)
+ */
+
+static struct resource stmpe_adc_resources[] = {
+ {
+ .name = "STMPE_TEMP_SENS",
+ .flags = IORESOURCE_IRQ,
+ },
+ {
+ .name = "STMPE_ADC",
+ .flags = IORESOURCE_IRQ,
+ },
+};
+
+static const struct mfd_cell stmpe_adc_cell = {
+ .name = "stmpe-adc",
+ .of_compatible = "st,stmpe-adc",
+ .resources = stmpe_adc_resources,
+ .num_resources = ARRAY_SIZE(stmpe_adc_resources),
+};
+
/*
* STMPE811 or STMPE610
*/
@@ -497,6 +519,11 @@ static struct stmpe_variant_block stmpe811_blocks[] = {
.irq = STMPE811_IRQ_TOUCH_DET,
.block = STMPE_BLOCK_TOUCHSCREEN,
},
+ {
+ .cell = &stmpe_adc_cell,
+ .irq = STMPE811_IRQ_TEMP_SENS,
+ .block = STMPE_BLOCK_ADC,
+ },
};
static int stmpe811_enable(struct stmpe *stmpe, unsigned int blocks,
diff --git a/include/linux/mfd/stmpe.h b/include/linux/mfd/stmpe.h
index 4a827af17e59..90700013f56d 100644
--- a/include/linux/mfd/stmpe.h
+++ b/include/linux/mfd/stmpe.h
@@ -10,6 +10,17 @@
#include <linux/mutex.h>
+#define SAMPLE_TIME(x) ((x & 0xf) << 4)
+#define MOD_12B(x) ((x & 0x1) << 3)
+#define REF_SEL(x) ((x & 0x1) << 1)
+#define ADC_FREQ(x) (x & 0x3)
+#define AVE_CTRL(x) ((x & 0x3) << 6)
+#define DET_DELAY(x) ((x & 0x7) << 3)
+#define SETTLING(x) (x & 0x7)
+#define FRACTION_Z(x) (x & 0x7)
+#define I_DRIVE(x) (x & 0x1)
+#define OP_MODE(x) ((x & 0x7) << 1)
+
struct device;
struct regulator;
--
2.19.1
