[PATCH v10 3/5] input: touchscreen: mxs-lradc: Add support for touchscreen
From: Ksenija Stanojevic
Date: Sun Nov 20 2016 - 05:58:09 EST
Add 4-wire/5-wire touchscreen controller.
Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@xxxxxxxxx>
---
Changes in v10:
- none
Changes in v9:
- none
Changes in v8:
- rebase onto 4.9-rc1
Changes in v7:
- remove touch_ret variable in probe and use ret instead
- make error check on of_property_read_u32 in probe
Changes in v6:
- update copyright
Changes in v5:
- add field void __iomem *base to struct mxs_lradc_adc
- change arguments in all functions for accessing I/O memory
to follow the previous change.
- use devm_ioremap for mapping I/O memory
Changes in v4:
- update copyright
- use platform_get_irq_byname
- use irq_of_parse_and_map
Changes in v3:
- make buffer large enough for timestamps
- remove unnecessary blank lines
Changes in v2:
- improve commit message
- do not change spacing in Kconfig
- impove formating
- remove wrapper show_scale_avail
- use correct syntax for comments
- use devm_iio_trigger_alloc
- do not allocate buffer dynamically
- use iio_device_claim_*_mode helpers
- add spinlock in struct mxs_lradc_ts to enable locking in interrupt handler
- only grab irqs that are relevant to adc
- remove blank line at the end of the file
- change licence to GPL
- add copyright
drivers/input/touchscreen/Kconfig | 10 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/mxs-lradc-ts.c | 743 +++++++++++++++++++++++++++++++
3 files changed, 754 insertions(+)
create mode 100644 drivers/input/touchscreen/mxs-lradc-ts.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index efca013..8ff915e 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -841,6 +841,16 @@ config TOUCHSCREEN_USB_COMPOSITE
To compile this driver as a module, choose M here: the
module will be called usbtouchscreen.
+config TOUCHSCREEN_MXS_LRADC
+ tristate "Freescale i.MX23/i.MX28 LRADC touchscreen"
+ depends on MFD_MXS_LRADC
+ help
+ Say Y here if you have a touchscreen connected to the low-resolution
+ analog-to-digital converter (LRADC) on an i.MX23 or i.MX28 processor.
+
+ To compile this driver as a module, choose M here: the module will be
+ called mxs-lradc-ts.
+
config TOUCHSCREEN_MX25
tristate "Freescale i.MX25 touchscreen input driver"
depends on MFD_MX25_TSADC
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 81b8645..97e1bb7 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_TOUCHSCREEN_INTEL_MID) += intel-mid-touch.o
obj-$(CONFIG_TOUCHSCREEN_IPROC) += bcm_iproc_tsc.o
obj-$(CONFIG_TOUCHSCREEN_LPC32XX) += lpc32xx_ts.o
obj-$(CONFIG_TOUCHSCREEN_MAX11801) += max11801_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MXS_LRADC) += mxs-lradc-ts.o
obj-$(CONFIG_TOUCHSCREEN_MX25) += fsl-imx25-tcq.o
obj-$(CONFIG_TOUCHSCREEN_MC13783) += mc13783_ts.o
obj-$(CONFIG_TOUCHSCREEN_MCS5000) += mcs5000_ts.o
diff --git a/drivers/input/touchscreen/mxs-lradc-ts.c b/drivers/input/touchscreen/mxs-lradc-ts.c
new file mode 100644
index 0000000..a59102b
--- /dev/null
+++ b/drivers/input/touchscreen/mxs-lradc-ts.c
@@ -0,0 +1,743 @@
+/*
+ * Freescale MXS LRADC touchscreen driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ * Copyright (c) 2016 Ksenija Stanojevic <ksenija.stanojevic@xxxxxxxxx>
+ *
+ * Authors:
+ * Marek Vasut <marex@xxxxxxx>
+ * Ksenija Stanojevic <ksenija.stanojevic@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mxs-lradc.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+const char *mxs_lradc_ts_irq_names[] = {
+ "mxs-lradc-touchscreen",
+ "mxs-lradc-channel6",
+ "mxs-lradc-channel7",
+};
+
+/*
+ * Touchscreen handling
+ */
+enum mxs_lradc_ts_plate {
+ LRADC_TOUCH = 0,
+ LRADC_SAMPLE_X,
+ LRADC_SAMPLE_Y,
+ LRADC_SAMPLE_PRESSURE,
+ LRADC_SAMPLE_VALID,
+};
+
+struct mxs_lradc_ts {
+ struct mxs_lradc *lradc;
+ struct device *dev;
+
+ void __iomem *base;
+ /*
+ * When the touchscreen is enabled, we give it two private virtual
+ * channels: #6 and #7. This means that only 6 virtual channels (instead
+ * of 8) will be available for buffered capture.
+ */
+#define TOUCHSCREEN_VCHANNEL1 7
+#define TOUCHSCREEN_VCHANNEL2 6
+
+ struct input_dev *ts_input;
+
+ enum mxs_lradc_ts_plate cur_plate; /* state machine */
+ bool ts_valid;
+ unsigned int ts_x_pos;
+ unsigned int ts_y_pos;
+ unsigned int ts_pressure;
+
+ /* handle touchscreen's physical behaviour */
+ /* samples per coordinate */
+ unsigned int over_sample_cnt;
+ /* time clocks between samples */
+ unsigned int over_sample_delay;
+ /* time in clocks to wait after the plates where switched */
+ unsigned int settling_delay;
+ spinlock_t lock;
+};
+
+static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_PLATE_MASK;
+ return LRADC_CTRL0_MX28_PLATE_MASK;
+}
+
+static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
+ return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
+}
+
+static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
+ return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
+ return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
+}
+
+static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
+{
+ if (lradc->soc == IMX23_LRADC)
+ return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
+ return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static bool mxs_lradc_check_touch_event(struct mxs_lradc_ts *ts)
+{
+ return !!(readl(ts->base + LRADC_STATUS) &
+ LRADC_STATUS_TOUCH_DETECT_RAW);
+}
+
+static void mxs_lradc_map_ts_channel(struct mxs_lradc_ts *ts, unsigned int vch,
+ unsigned int ch)
+{
+ mxs_lradc_reg_clear(ts->base, LRADC_CTRL4_LRADCSELECT_MASK(vch),
+ LRADC_CTRL4);
+ mxs_lradc_reg_set(ts->base, LRADC_CTRL4_LRADCSELECT(vch, ch),
+ LRADC_CTRL4);
+}
+
+static void mxs_lradc_setup_ts_channel(struct mxs_lradc_ts *ts, unsigned int ch)
+{
+ /*
+ * prepare for oversampling conversion
+ *
+ * from the datasheet:
+ * "The ACCUMULATE bit in the appropriate channel register
+ * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+ * otherwise, the IRQs will not fire."
+ */
+ mxs_lradc_reg_wrt(ts->base, LRADC_CH_ACCUMULATE |
+ LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1),
+ LRADC_CH(ch));
+
+ /* from the datasheet:
+ * "Software must clear this register in preparation for a
+ * multi-cycle accumulation.
+ */
+ mxs_lradc_reg_clear(ts->base, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
+
+ /*
+ * prepare the delay/loop unit according to the oversampling count
+ *
+ * from the datasheet:
+ * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
+ * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
+ * the LRADC will not trigger the delay group."
+ */
+ mxs_lradc_reg_wrt(ts->base, LRADC_DELAY_TRIGGER(1 << ch) |
+ LRADC_DELAY_TRIGGER_DELAYS(0) |
+ LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
+ LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
+ LRADC_DELAY(3));
+
+ mxs_lradc_reg_clear(ts->base, LRADC_CTRL1_LRADC_IRQ(ch), LRADC_CTRL1);
+
+ /*
+ * after changing the touchscreen plates setting
+ * the signals need some initial time to settle. Start the
+ * SoC's delay unit and start the conversion later
+ * and automatically.
+ */
+ mxs_lradc_reg_wrt(ts->base,
+ LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
+ LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
+ LRADC_DELAY_KICK |
+ LRADC_DELAY_DELAY(ts->settling_delay),
+ LRADC_DELAY(2));
+}
+
+/*
+ * Pressure detection is special:
+ * We want to do both required measurements for the pressure detection in
+ * one turn. Use the hardware features to chain both conversions and let the
+ * hardware report one interrupt if both conversions are done
+ */
+static void mxs_lradc_setup_ts_pressure(struct mxs_lradc_ts *ts,
+ unsigned int ch1, unsigned int ch2)
+{
+ u32 reg;
+
+ /*
+ * prepare for oversampling conversion
+ *
+ * from the datasheet:
+ * "The ACCUMULATE bit in the appropriate channel register
+ * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+ * otherwise, the IRQs will not fire."
+ */
+ reg = LRADC_CH_ACCUMULATE |
+ LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1);
+ mxs_lradc_reg_wrt(ts->base, reg, LRADC_CH(ch1));
+ mxs_lradc_reg_wrt(ts->base, reg, LRADC_CH(ch2));
+
+ /* from the datasheet:
+ * "Software must clear this register in preparation for a
+ * multi-cycle accumulation.
+ */
+ mxs_lradc_reg_clear(ts->base, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
+ mxs_lradc_reg_clear(ts->base, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
+
+ /* prepare the delay/loop unit according to the oversampling count */
+ mxs_lradc_reg_wrt(ts->base,
+ LRADC_DELAY_TRIGGER(1 << ch1) |
+ LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
+ LRADC_DELAY_TRIGGER_DELAYS(0) |
+ LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
+ LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
+ LRADC_DELAY(3));
+
+ mxs_lradc_reg_clear(ts->base, LRADC_CTRL1_LRADC_IRQ(ch2), LRADC_CTRL1);
+
+ /*
+ * after changing the touchscreen plates setting
+ * the signals need some initial time to settle. Start the
+ * SoC's delay unit and start the conversion later
+ * and automatically.
+ */
+ mxs_lradc_reg_wrt(ts->base,
+ LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
+ LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
+ LRADC_DELAY_KICK |
+ LRADC_DELAY_DELAY(ts->settling_delay), LRADC_DELAY(2));
+}
+
+static unsigned int mxs_lradc_ts_read_raw_channel(struct mxs_lradc_ts *ts,
+ unsigned int channel)
+{
+ u32 reg;
+ unsigned int num_samples, val;
+
+ reg = readl(ts->base + LRADC_CH(channel));
+ if (reg & LRADC_CH_ACCUMULATE)
+ num_samples = ts->over_sample_cnt;
+ else
+ num_samples = 1;
+
+ val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
+ return val / num_samples;
+}
+
+static unsigned int mxs_lradc_read_ts_pressure(struct mxs_lradc_ts *ts,
+ unsigned int ch1, unsigned int ch2)
+{
+ u32 reg, mask;
+ unsigned int pressure, m1, m2;
+
+ mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
+ reg = readl(ts->base + LRADC_CTRL1) & mask;
+
+ while (reg != mask) {
+ reg = readl(ts->base + LRADC_CTRL1) & mask;
+ dev_dbg(ts->dev, "One channel is still busy: %X\n", reg);
+ }
+
+ m1 = mxs_lradc_ts_read_raw_channel(ts, ch1);
+ m2 = mxs_lradc_ts_read_raw_channel(ts, ch2);
+
+ if (m2 == 0) {
+ dev_warn(ts->dev, "Cannot calculate pressure\n");
+ return 1 << (LRADC_RESOLUTION - 1);
+ }
+
+ /* simply scale the value from 0 ... max ADC resolution */
+ pressure = m1;
+ pressure *= (1 << LRADC_RESOLUTION);
+ pressure /= m2;
+
+ dev_dbg(ts->dev, "Pressure = %u\n", pressure);
+ return pressure;
+}
+
+#define TS_CH_XP 2
+#define TS_CH_YP 3
+#define TS_CH_XM 4
+#define TS_CH_YM 5
+
+/*
+ * YP(open)--+-------------+
+ * | |--+
+ * | | |
+ * YM(-)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(weak+) XM(open)
+ *
+ * "weak+" means 200k Ohm VDDIO
+ * (-) means GND
+ */
+static void mxs_lradc_setup_touch_detection(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ /*
+ * In order to detect a touch event the 'touch detect enable' bit
+ * enables:
+ * - a weak pullup to the X+ connector
+ * - a strong ground at the Y- connector
+ */
+ mxs_lradc_reg_clear(ts->base, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(ts->base, mxs_lradc_touch_detect_bit(lradc),
+ LRADC_CTRL0);
+}
+
+/*
+ * YP(meas)--+-------------+
+ * | |--+
+ * | | |
+ * YM(open)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(+) XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_x_pos(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ mxs_lradc_reg_clear(ts->base, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(ts->base, mxs_lradc_drive_x_plate(lradc),
+ LRADC_CTRL0);
+
+ ts->cur_plate = LRADC_SAMPLE_X;
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
+ mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ * YP(+)--+-------------+
+ * | |--+
+ * | | |
+ * YM(-)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(open) XM(meas)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_y_pos(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ mxs_lradc_reg_clear(ts->base, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(ts->base, mxs_lradc_drive_y_plate(lradc),
+ LRADC_CTRL0);
+
+ ts->cur_plate = LRADC_SAMPLE_Y;
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
+ mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ * YP(+)--+-------------+
+ * | |--+
+ * | | |
+ * YM(meas)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(meas) XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_pressure(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ mxs_lradc_reg_clear(ts->base, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+ mxs_lradc_reg_set(ts->base, mxs_lradc_drive_pressure(lradc),
+ LRADC_CTRL0);
+
+ ts->cur_plate = LRADC_SAMPLE_PRESSURE;
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
+ mxs_lradc_setup_ts_pressure(ts, TOUCHSCREEN_VCHANNEL2,
+ TOUCHSCREEN_VCHANNEL1);
+}
+
+static void mxs_lradc_enable_touch_detection(struct mxs_lradc_ts *ts)
+{
+ mxs_lradc_setup_touch_detection(ts);
+
+ ts->cur_plate = LRADC_TOUCH;
+ mxs_lradc_reg_clear(ts->base, LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
+ mxs_lradc_reg_set(ts->base, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ LRADC_CTRL1);
+}
+
+static void mxs_lradc_start_touch_event(struct mxs_lradc_ts *ts)
+{
+ mxs_lradc_reg_clear(ts->base,
+ LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ LRADC_CTRL1);
+ mxs_lradc_reg_set(ts->base,
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1),
+ LRADC_CTRL1);
+ /*
+ * start with the Y-pos, because it uses nearly the same plate
+ * settings like the touch detection
+ */
+ mxs_lradc_prepare_y_pos(ts);
+}
+
+static void mxs_lradc_report_ts_event(struct mxs_lradc_ts *ts)
+{
+ input_report_abs(ts->ts_input, ABS_X, ts->ts_x_pos);
+ input_report_abs(ts->ts_input, ABS_Y, ts->ts_y_pos);
+ input_report_abs(ts->ts_input, ABS_PRESSURE, ts->ts_pressure);
+ input_report_key(ts->ts_input, BTN_TOUCH, 1);
+ input_sync(ts->ts_input);
+}
+
+static void mxs_lradc_complete_touch_event(struct mxs_lradc_ts *ts)
+{
+ mxs_lradc_setup_touch_detection(ts);
+ ts->cur_plate = LRADC_SAMPLE_VALID;
+ /*
+ * start a dummy conversion to burn time to settle the signals
+ * note: we are not interested in the conversion's value
+ */
+ mxs_lradc_reg_wrt(ts->base, 0, LRADC_CH(TOUCHSCREEN_VCHANNEL1));
+ mxs_lradc_reg_clear(ts->base,
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2),
+ LRADC_CTRL1);
+ mxs_lradc_reg_wrt(ts->base,
+ LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
+ LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
+ LRADC_DELAY(2));
+}
+
+/*
+ * in order to avoid false measurements, report only samples where
+ * the surface is still touched after the position measurement
+ */
+static void mxs_lradc_finish_touch_event(struct mxs_lradc_ts *ts, bool valid)
+{
+ /* if it is still touched, report the sample */
+ if (valid && mxs_lradc_check_touch_event(ts)) {
+ ts->ts_valid = true;
+ mxs_lradc_report_ts_event(ts);
+ }
+
+ /* if it is even still touched, continue with the next measurement */
+ if (mxs_lradc_check_touch_event(ts)) {
+ mxs_lradc_prepare_y_pos(ts);
+ return;
+ }
+
+ if (ts->ts_valid) {
+ /* signal the release */
+ ts->ts_valid = false;
+ input_report_key(ts->ts_input, BTN_TOUCH, 0);
+ input_sync(ts->ts_input);
+ }
+
+ /* if it is released, wait for the next touch via IRQ */
+ ts->cur_plate = LRADC_TOUCH;
+ mxs_lradc_reg_wrt(ts->base, 0, LRADC_DELAY(2));
+ mxs_lradc_reg_wrt(ts->base, 0, LRADC_DELAY(3));
+ mxs_lradc_reg_clear(ts->base,
+ LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1),
+ LRADC_CTRL1);
+ mxs_lradc_reg_set(ts->base, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ LRADC_CTRL1);
+}
+
+/* touchscreen's state machine */
+static void mxs_lradc_handle_touch(struct mxs_lradc_ts *ts)
+{
+ switch (ts->cur_plate) {
+ case LRADC_TOUCH:
+ if (mxs_lradc_check_touch_event(ts))
+ mxs_lradc_start_touch_event(ts);
+ mxs_lradc_reg_clear(ts->base, LRADC_CTRL1_TOUCH_DETECT_IRQ,
+ LRADC_CTRL1);
+ return;
+
+ case LRADC_SAMPLE_Y:
+ ts->ts_y_pos =
+ mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_prepare_x_pos(ts);
+ return;
+
+ case LRADC_SAMPLE_X:
+ ts->ts_x_pos =
+ mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_prepare_pressure(ts);
+ return;
+
+ case LRADC_SAMPLE_PRESSURE:
+ ts->ts_pressure =
+ mxs_lradc_read_ts_pressure(ts,
+ TOUCHSCREEN_VCHANNEL2,
+ TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_complete_touch_event(ts);
+ return;
+
+ case LRADC_SAMPLE_VALID:
+ mxs_lradc_finish_touch_event(ts, 1);
+ break;
+ }
+}
+
+/* IRQ Handling */
+static irqreturn_t mxs_lradc_ts_handle_irq(int irq, void *data)
+{
+ struct mxs_lradc_ts *ts = data;
+ struct mxs_lradc *lradc = ts->lradc;
+ unsigned long reg = readl(ts->base + LRADC_CTRL1);
+ u32 clr_irq = mxs_lradc_irq_mask(lradc);
+ const u32 ts_irq_mask =
+ LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
+ unsigned long flags;
+
+ if (!(reg & mxs_lradc_irq_mask(lradc)))
+ return IRQ_NONE;
+
+ if (reg & ts_irq_mask) {
+ spin_lock_irqsave(&ts->lock, flags);
+ mxs_lradc_handle_touch(ts);
+ spin_unlock_irqrestore(&ts->lock, flags);
+ /* Make sure we don't clear the next conversion's interrupt. */
+ clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
+ mxs_lradc_reg_clear(ts->base, reg & clr_irq, LRADC_CTRL1);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int mxs_lradc_ts_open(struct input_dev *dev)
+{
+ struct mxs_lradc_ts *ts = input_get_drvdata(dev);
+
+ /* Enable the touch-detect circuitry. */
+ mxs_lradc_enable_touch_detection(ts);
+
+ return 0;
+}
+
+static void mxs_lradc_ts_stop(struct mxs_lradc_ts *ts)
+{
+ int i;
+ struct mxs_lradc *lradc = ts->lradc;
+
+ /* stop all interrupts from firing */
+ mxs_lradc_reg_clear(ts->base, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
+
+ /* Power-down touchscreen touch-detect circuitry. */
+ mxs_lradc_reg_clear(ts->base, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+
+ mxs_lradc_reg_clear(ts->base,
+ lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+ LRADC_CTRL1);
+
+ for (i = 1; i < LRADC_MAX_DELAY_CHANS; i++)
+ mxs_lradc_reg_wrt(ts->base, 0, LRADC_DELAY(i));
+}
+
+static void mxs_lradc_ts_close(struct input_dev *dev)
+{
+ struct mxs_lradc_ts *ts = input_get_drvdata(dev);
+
+ mxs_lradc_ts_stop(ts);
+}
+
+static void mxs_lradc_ts_hw_init(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ /* Configure the touchscreen type */
+ if (lradc->soc == IMX28_LRADC) {
+ mxs_lradc_reg_clear(ts->base,
+ LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+ LRADC_CTRL0);
+
+ if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
+ mxs_lradc_reg_set(ts->base,
+ LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+ LRADC_CTRL0);
+ }
+}
+
+static int mxs_lradc_ts_register(struct mxs_lradc_ts *ts)
+{
+ struct input_dev *input = ts->ts_input;
+ struct device *dev = ts->dev;
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = "mxs-lradc-ts";
+ input->id.bustype = BUS_HOST;
+ input->open = mxs_lradc_ts_open;
+ input->close = mxs_lradc_ts_close;
+
+ __set_bit(EV_ABS, input->evbit);
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(BTN_TOUCH, input->keybit);
+ __set_bit(INPUT_PROP_DIRECT, input->propbit);
+ input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
+ input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
+ input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
+ 0, 0);
+
+ ts->ts_input = input;
+ input_set_drvdata(input, ts);
+
+ return input_register_device(input);
+}
+
+static int mxs_lradc_ts_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->parent->of_node;
+ struct mxs_lradc *lradc = dev_get_platdata(dev);
+ struct mxs_lradc_ts *ts;
+ struct resource *iores;
+ int ret, irq, virq, i;
+ u32 ts_wires = 0, adapt;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, ts);
+
+ ts->lradc = lradc;
+ ts->dev = dev;
+ spin_lock_init(&ts->lock);
+
+ iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ts->base = devm_ioremap(dev, iores->start, resource_size(iores));
+ if (IS_ERR(ts->base))
+ return PTR_ERR(ts->base);
+
+ ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
+ &ts_wires);
+ if (ret)
+ return ret;
+
+ if (of_property_read_u32(node, "fsl,ave-ctrl", &adapt)) {
+ ts->over_sample_cnt = 4;
+ } else {
+ if (adapt >= 1 || adapt <= 32) {
+ ts->over_sample_cnt = adapt;
+ } else {
+ dev_err(ts->dev, "Invalid sample count (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ }
+
+ if (of_property_read_u32(node, "fsl,ave-delay", &adapt)) {
+ ts->over_sample_delay = 2;
+ } else {
+ if (adapt >= 2 || adapt <= LRADC_DELAY_DELAY_MASK + 1) {
+ ts->over_sample_delay = adapt;
+ } else {
+ dev_err(ts->dev, "Invalid sample delay (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ }
+
+ if (of_property_read_u32(node, "fsl,settling", &adapt)) {
+ ts->settling_delay = 10;
+ } else {
+ if (adapt >= 1 || adapt <= LRADC_DELAY_DELAY_MASK) {
+ ts->settling_delay = adapt;
+ } else {
+ dev_err(ts->dev, "Invalid settling delay (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ }
+
+ ret = stmp_reset_block(ts->base);
+ if (ret)
+ return ret;
+
+ mxs_lradc_ts_hw_init(ts);
+
+ for (i = 0; i < 3; i++) {
+ irq = platform_get_irq_byname(pdev, mxs_lradc_ts_irq_names[i]);
+ if (irq < 0)
+ return irq;
+
+ virq = irq_of_parse_and_map(node, irq);
+
+ ret = devm_request_irq(dev, virq,
+ mxs_lradc_ts_handle_irq,
+ 0, mxs_lradc_ts_irq_names[i], ts);
+ if (ret)
+ return ret;
+ }
+
+ ret = mxs_lradc_ts_register(ts);
+ if (!ret)
+ goto error;
+
+ return 0;
+
+error:
+ mxs_lradc_ts_stop(ts);
+
+ return ret;
+}
+
+static struct platform_driver mxs_lradc_ts_driver = {
+ .driver = {
+ .name = "mxs-lradc-ts",
+ },
+ .probe = mxs_lradc_ts_probe,
+};
+module_platform_driver(mxs_lradc_ts_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@xxxxxxx>");
+MODULE_DESCRIPTION("Freescale MXS LRADC touchscreen driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-lradc-ts");
--
1.9.1