Re: [PATCH v11 3/5] input: touchscreen: mxs-lradc: Add support for touchscreen
flat view
From: Ksenija Stanojević <ksenija.stanojevic@gmail.com>
Date: 2017-01-23 11:00:53
Also in:
linux-iio, lkml
Hi Dmitry, On Tue, Dec 27, 2016 at 11:39 PM, Dmitry Torokhov [off-list ref] wrote:
Hi Ksenija, On Thu, Dec 08, 2016 at 11:27:09PM +0100, Ksenija Stanojevic wrote:quoted
Add 4-wire/5-wire touchscreen controller. Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com> --- Changes in v11: - use dev_get_drvdata instead dev_get_platdata - use writel instead mxs_lradc_reg_* functions 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 | 739 +++++++++++++++++++++++++++++++ 3 files changed, 750 insertions(+) create mode 100644 drivers/input/touchscreen/mxs-lradc-ts.cdiff --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_TSADCdiff --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.odiff --git a/drivers/input/touchscreen/mxs-lradc-ts.c b/drivers/input/touchscreen/mxs-lradc-ts.c new file mode 100644 index 0000000..a222e35 --- /dev/null +++ b/drivers/input/touchscreen/mxs-lradc-ts.c@@ -0,0 +1,739 @@ +/* + * Freescale MXS LRADC touchscreen driver + * + * Copyright (c) 2012 DENX Software Engineering, GmbH. + * Copyright (c) 2016 Ksenija Stanojevic <ksenija.stanojevic@gmail.com> + * + * Authors: + * Marek Vasut <marex@denx.de> + * Ksenija Stanojevic <ksenija.stanojevic@gmail.com> + * + * 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;I wonder if, instead of doing conditionals on every operation, you could attach const struct pointer to your device with needed values/masks.
Ok, I can try that.
quoted
+} + +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) +{ + writel(LRADC_CTRL4_LRADCSELECT_MASK(vch), + ts->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR); + writel(LRADC_CTRL4_LRADCSELECT(vch, ch), + ts->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET); +} + +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." + */ + writel(LRADC_CH_ACCUMULATE | + LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1), + ts->base + LRADC_CH(ch)); + + /* from the datasheet: + * "Software must clear this register in preparation for a + * multi-cycle accumulation. + */ + writel(LRADC_CH_VALUE_MASK, + ts->base + LRADC_CH(ch) + STMP_OFFSET_REG_CLR); + + /* + * 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." + */ + writel(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), + ts->base + LRADC_DELAY(3)); + + writel(LRADC_CTRL1_LRADC_IRQ(ch), + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + + /* + * 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. + */ + writel(LRADC_DELAY_TRIGGER(0) | LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | + LRADC_DELAY_KICK | LRADC_DELAY_DELAY(ts->settling_delay), + ts->base + 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); + writel(reg, ts->base + LRADC_CH(ch1)); + writel(reg, ts->base + LRADC_CH(ch2)); + + /* from the datasheet: + * "Software must clear this register in preparation for a + * multi-cycle accumulation. + */ + writel(LRADC_CH_VALUE_MASK, + ts->base + LRADC_CH(ch1) + STMP_OFFSET_REG_CLR); + writel(LRADC_CH_VALUE_MASK, + ts->base + LRADC_CH(ch2) + STMP_OFFSET_REG_CLR); + + /* prepare the delay/loop unit according to the oversampling count */ + writel(LRADC_DELAY_TRIGGER(1 << ch1) | LRADC_DELAY_TRIGGER(1 << ch2) | + LRADC_DELAY_TRIGGER_DELAYS(0) | + LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) | + LRADC_DELAY_DELAY(ts->over_sample_delay - 1), + ts->base + LRADC_DELAY(3)); + + writel(LRADC_CTRL1_LRADC_IRQ(ch2), + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + + /* + * 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. + */ + writel(LRADC_DELAY_TRIGGER(0) | LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | + LRADC_DELAY_KICK | LRADC_DELAY_DELAY(ts->settling_delay), + ts->base + 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 + */ + writel(mxs_lradc_plate_mask(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); + writel(mxs_lradc_touch_detect_bit(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); +} + +/* + * 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; + + writel(mxs_lradc_plate_mask(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); + writel(mxs_lradc_drive_x_plate(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); + + 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; + + writel(mxs_lradc_plate_mask(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); + writel(mxs_lradc_drive_y_plate(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); + + 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; + + writel(mxs_lradc_plate_mask(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); + writel(mxs_lradc_drive_pressure(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); + + 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; + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ | LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); +} + +static void mxs_lradc_start_touch_event(struct mxs_lradc_ts *ts) +{ + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + writel(LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1), + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); + /* + * 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 + */ + writel(0, ts->base + LRADC_CH(TOUCHSCREEN_VCHANNEL1)); + writel(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) | + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2), + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + writel(LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) | + LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), + ts->base + 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; + writel(0, ts->base + LRADC_DELAY(2)); + writel(0, ts->base + LRADC_DELAY(3)); + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ | + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) | + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1), + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET); +} + +/* 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); + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + 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)); + writel(reg & clr_irq, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + } + + 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 */ + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN | + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) | + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + + /* Power-down touchscreen touch-detect circuitry. */ + writel(mxs_lradc_plate_mask(lradc), + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); + + writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET, + ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR); + + for (i = 1; i < LRADC_MAX_DELAY_CHANS; i++) + writel(0, ts->base + 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) { + writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE, + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR); + + if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE) + writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE, + ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET); + } +} + +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_drvdata(dev->parent); + 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);Why do we need this? I'd expect parent to fully prepare interrupts for the child to use. I.e. I'd expect I could do platform_get_irq_byname() and them go straight to devm_request_irq().
Well probe fails and devm_request_irq trows error -22 in that case, so I think that use of irq_of_parse_and_map is needed.
quoted
+ + 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);Why do you want to stop only if mxs_lradc_ts_register() fails? If open() has been called, then close() should be called on error automatically. That said, shouldn't you call mxs_lradc_ts_stop() before requesting interrupts, just to make sure they do not start firing early (even though I think it should be safe if they do)?
Ok, I will do that. Thanks, Ksenija
Thanks.quoted
+ + 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 [off-list ref]"); +MODULE_DESCRIPTION("Freescale MXS LRADC touchscreen driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:mxs-lradc-ts"); -- 1.9.1-- Dmitry