From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH v8 6/8] input: touchscreen: imx25 tcq driver Date: Tue, 17 Nov 2015 10:17:20 -0800 Message-ID: <20151117181720.GC29423@dtor-ws> References: <1447675269-8831-1-git-send-email-mpa@pengutronix.de> <1447675269-8831-7-git-send-email-mpa@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1447675269-8831-7-git-send-email-mpa-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Markus Pargmann Cc: Shawn Guo , Jonathan Cameron , Lee Jones , Denis Carikli , Eric =?iso-8859-1?Q?B=E9nard?= , Sascha Hauer , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Hartmut Knaack , Fabio Estevam , Juergen Borleis List-Id: devicetree@vger.kernel.org On Mon, Nov 16, 2015 at 01:01:07PM +0100, Markus Pargmann wrote: > This is a driver for the imx25 ADC/TSC module. It controls the > touchscreen conversion queue and creates a touchscreen input device. > The driver currently only supports 4 wire touchscreens. The driver uses > a simple conversion queue of precharge, touch detection, X measurement, > Y measurement, precharge and another touch detection. > > This driver uses the regmap from the parent to setup some touch specific > settings in the core driver and setup a idle configuration with touch > detection. > > Signed-off-by: Markus Pargmann > Signed-off-by: Denis Carikli > > [fix clock's period calculation] > [fix calculation of the 'settling' value] > Signed-off-by: Juergen Borleis > --- > > Notes: > Changes in v7: > - Moved clk_prepare_enable() and mx25_tcq_init() into mx25_tcq_open(). This > was done to be able to use devm_request_threaded_irq(). > - Cleanup of the probe function through above change > - Removed mx25_tcq_remove(), not necessary now > > drivers/input/touchscreen/Kconfig | 6 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/fsl-imx25-tcq.c | 600 ++++++++++++++++++++++++++++++ > 3 files changed, 607 insertions(+) > create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index ae33da7ab51f..b44651d33080 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -811,6 +811,12 @@ config TOUCHSCREEN_USB_COMPOSITE > To compile this driver as a module, choose M here: the > module will be called usbtouchscreen. > > +config TOUCHSCREEN_MX25 > + tristate "Freescale i.MX25 touchscreen input driver" > + depends on MFD_MX25_TSADC > + help > + Enable support for touchscreen connected to your i.MX25. > + To compile this driver as a module... > config TOUCHSCREEN_MC13783 > tristate "Freescale MC13783 touchscreen input driver" > depends on MFD_MC13XXX > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > index cbaa6abb08da..77a2ac54101a 100644 > --- a/drivers/input/touchscreen/Makefile > +++ b/drivers/input/touchscreen/Makefile > @@ -45,6 +45,7 @@ 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-$(CONFIG_TOUCHSCREEN_MX25) += fsl-imx25-tcq.o > obj-$(CONFIG_TOUCHSCREEN_MC13783) += mc13783_ts.o > obj-$(CONFIG_TOUCHSCREEN_MCS5000) += mcs5000_ts.o > obj-$(CONFIG_TOUCHSCREEN_MIGOR) += migor_ts.o > diff --git a/drivers/input/touchscreen/fsl-imx25-tcq.c b/drivers/input/touchscreen/fsl-imx25-tcq.c > new file mode 100644 > index 000000000000..c833cd814972 > --- /dev/null > +++ b/drivers/input/touchscreen/fsl-imx25-tcq.c > @@ -0,0 +1,600 @@ > +/* > + * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann > + * > + * 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. > + * > + * Based on driver from 2011: > + * Juergen Beisert, Pengutronix > + * > + * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue) > + * connected to the imx25 ADC. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +static const char mx25_tcq_name[] = "mx25-tcq"; > + > +enum mx25_tcq_mode { > + MX25_TS_4WIRE, > +}; > + > +struct mx25_tcq_priv { > + struct regmap *regs; > + struct regmap *core_regs; > + struct input_dev *idev; > + enum mx25_tcq_mode mode; > + unsigned int pen_threshold; > + unsigned int sample_count; > + unsigned int expected_samples; > + unsigned int pen_debounce; > + unsigned int settling_time; > + struct clk *clk; > + int irq; > +}; > + > +static struct regmap_config mx25_tcq_regconfig = { > + .fast_io = true, > + .max_register = 0x5c, > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +static const struct of_device_id mx25_tcq_ids[] = { > + { .compatible = "fsl,imx25-tcq", }, > + { /* Sentinel */ } > +}; > + > +#define TSC_4WIRE_PRE_INDEX 0 > +#define TSC_4WIRE_X_INDEX 1 > +#define TSC_4WIRE_Y_INDEX 2 > +#define TSC_4WIRE_POST_INDEX 3 > +#define TSC_4WIRE_LEAVE 4 > + > +#define MX25_TSC_DEF_THRESHOLD 80 > +#define TSC_MAX_SAMPLES 16 > + > +#define MX25_TSC_REPEAT_WAIT 14 > + > +enum mx25_adc_configurations { > + MX25_CFG_PRECHARGE = 0, > + MX25_CFG_TOUCH_DETECT, > + MX25_CFG_X_MEASUREMENT, > + MX25_CFG_Y_MEASUREMENT, > +}; > + > +#define MX25_PRECHARGE_VALUE (\ > + MX25_ADCQ_CFG_YPLL_OFF | \ > + MX25_ADCQ_CFG_XNUR_OFF | \ > + MX25_ADCQ_CFG_XPUL_HIGH | \ > + MX25_ADCQ_CFG_REFP_INT | \ > + MX25_ADCQ_CFG_IN_XP | \ > + MX25_ADCQ_CFG_REFN_NGND2 | \ > + MX25_ADCQ_CFG_IGS) > + > +#define MX25_TOUCH_DETECT_VALUE (\ > + MX25_ADCQ_CFG_YNLR | \ > + MX25_ADCQ_CFG_YPLL_OFF | \ > + MX25_ADCQ_CFG_XNUR_OFF | \ > + MX25_ADCQ_CFG_XPUL_OFF | \ > + MX25_ADCQ_CFG_REFP_INT | \ > + MX25_ADCQ_CFG_IN_XP | \ > + MX25_ADCQ_CFG_REFN_NGND2 | \ > + MX25_ADCQ_CFG_PENIACK) > + > +static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv, > + unsigned int settling_cnt) > +{ > + u32 precharge_cfg = > + MX25_PRECHARGE_VALUE | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt); > + u32 touch_detect_cfg = > + MX25_TOUCH_DETECT_VALUE | > + MX25_ADCQ_CFG_NOS(1) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt); > + > + regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg); > + > + /* PRECHARGE */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE), > + precharge_cfg); > + > + /* TOUCH_DETECT */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT), > + touch_detect_cfg); > + > + /* X Measurement */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT), > + MX25_ADCQ_CFG_YPLL_OFF | > + MX25_ADCQ_CFG_XNUR_LOW | > + MX25_ADCQ_CFG_XPUL_HIGH | > + MX25_ADCQ_CFG_REFP_XP | > + MX25_ADCQ_CFG_IN_YP | > + MX25_ADCQ_CFG_REFN_XN | > + MX25_ADCQ_CFG_NOS(priv->sample_count) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt)); > + > + /* Y Measurement */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT), > + MX25_ADCQ_CFG_YNLR | > + MX25_ADCQ_CFG_YPLL_HIGH | > + MX25_ADCQ_CFG_XNUR_OFF | > + MX25_ADCQ_CFG_XPUL_OFF | > + MX25_ADCQ_CFG_REFP_YP | > + MX25_ADCQ_CFG_IN_XP | > + MX25_ADCQ_CFG_REFN_YN | > + MX25_ADCQ_CFG_NOS(priv->sample_count) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt)); > + > + /* Enable the touch detection right now */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg | > + MX25_ADCQ_CFG_IGS); > +} > + > +static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv, > + unsigned settling_cnt, int *items) > +{ > + imx25_setup_queue_cfgs(priv, settling_cnt); > + > + /* Setup the conversion queue */ > + regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0, > + MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) | > + MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) | > + MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) | > + MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) | > + MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) | > + MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT)); > + > + /* > + * We measure X/Y with 'sample_count' number of samples and execute a > + * touch detection twice, with 1 sample each > + */ > + priv->expected_samples = priv->sample_count * 2 + 2; > + *items = 6; > + > + return 0; > +} > + > +static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, > + MX25_ADCQ_CR_PDMSK); > +} > + > +static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0); > +} > + > +static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, > + MX25_ADCQ_MR_FDRY_IRQ); > +} > + > +static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0); > +} > + > +static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_FQS, > + MX25_ADCQ_CR_FQS); > +} > + > +static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_FQS, 0); > +} > + > +static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv) > +{ > + u32 tcqcr; > + > + regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, > + MX25_ADCQ_CR_FRST); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, 0); > + regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr); > +} > + > +static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv) > +{ > + /* stop the queue from looping */ > + mx25_tcq_force_queue_stop(priv); > + > + /* for a clean touch detection, preload the X plane */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE); > + > + /* waste some time now to pre-load the X plate to high voltage */ > + mx25_tcq_fifo_reset(priv); > + > + /* re-enable the detection right now */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, > + MX25_TOUCH_DETECT_VALUE | MX25_ADCQ_CFG_IGS); > + > + regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD, > + MX25_ADCQ_SR_PD); > + > + /* enable the pen down event to be a source for the interrupt */ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0); > + > + /* lets fire the next IRQ if someone touches the touchscreen */ > + mx25_tcq_enable_touch_irq(priv); > +} > + > +static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv, Why not void? What callers are supposed to do with the value? > + u32 *sample_buf, > + unsigned int samples) > +{ > + unsigned int x_pos = 0; > + unsigned int y_pos = 0; > + unsigned int touch_pre = 0; > + unsigned int touch_post = 0; > + unsigned int i; > + int ret = 0; > + > + for (i = 0; i < samples; i++) { > + unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]); > + unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]); > + > + switch (index) { > + case 1: > + touch_pre = val; > + break; > + case 2: > + x_pos = val; > + break; > + case 3: > + y_pos = val; > + break; > + case 5: > + touch_post = val; > + break; > + default: > + ret = -EINVAL; > + break; > + } > + } > + > + if (ret == 0 && samples != 0) { Where do we set ret to anything other than 0? > + /* > + * only if both touch measures are below a threshold, > + * the position is valid > + */ > + if (touch_pre < priv->pen_threshold && > + touch_post < priv->pen_threshold) { > + /* valid samples, generate a report */ > + x_pos /= priv->sample_count; > + y_pos /= priv->sample_count; > + input_report_abs(priv->idev, ABS_X, x_pos); > + input_report_abs(priv->idev, ABS_Y, y_pos); > + input_report_key(priv->idev, BTN_TOUCH, 1); > + input_sync(priv->idev); > + > + /* get next sample */ > + mx25_tcq_enable_fifo_irq(priv); > + } else if (touch_pre >= priv->pen_threshold && > + touch_post >= priv->pen_threshold) { > + /* > + * if both samples are invalid, > + * generate a release report > + */ > + input_report_key(priv->idev, BTN_TOUCH, 0); > + input_sync(priv->idev); > + mx25_tcq_re_enable_touch_detection(priv); > + } else { > + /* > + * if only one of both touch measurements are > + * below the threshold, still some bouncing > + * happens. Take additional samples in this > + * case to be sure > + */ > + mx25_tcq_enable_fifo_irq(priv); > + } > + } > + > + return ret; > +} > + > +static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id) > +{ > + struct mx25_tcq_priv *priv = dev_id; > + u32 sample_buf[TSC_MAX_SAMPLES]; > + unsigned int samples = 0; > + > + /* read all samples */ > + while (1) { > + u32 stats; > + > + regmap_read(priv->regs, MX25_ADCQ_SR, &stats); > + if (stats & MX25_ADCQ_SR_EMPT) > + break; > + > + if (samples < TSC_MAX_SAMPLES) { > + regmap_read(priv->regs, MX25_ADCQ_FIFO, > + &sample_buf[samples]); > + ++samples; > + } else { > + u32 discarded; > + /* discard samples */ > + regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded); > + } > + } > + > + mx25_tcq_create_event_for_4wire(priv, sample_buf, samples); > + > + return IRQ_HANDLED; > +} > + > +static irqreturn_t mx25_tcq_irq(int irq, void *dev_id) > +{ > + struct mx25_tcq_priv *priv = dev_id; > + u32 stat; > + int ret = IRQ_HANDLED; > + > + regmap_read(priv->regs, MX25_ADCQ_SR, &stat); Is there any concern that these reads will fail? > + > + if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR)) > + mx25_tcq_fifo_reset(priv); > + > + if (stat & MX25_ADCQ_SR_PD) { > + mx25_tcq_disable_touch_irq(priv); > + mx25_tcq_force_queue_start(priv); > + mx25_tcq_enable_fifo_irq(priv); > + } > + > + if (stat & MX25_ADCQ_SR_FDRY) { > + mx25_tcq_disable_fifo_irq(priv); > + ret = IRQ_WAKE_THREAD; > + } > + > + regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR | > + MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | > + MX25_ADCQ_SR_PD | MX25_ADCQ_SR_EOQ, > + MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | > + MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD | > + MX25_ADCQ_SR_EOQ); > + > + return ret; > +} > + > +/* configure the statemachine for a 4-wire touchscreen */ > +static int mx25_tcq_init(struct mx25_tcq_priv *priv) > +{ > + u32 tgcr; > + unsigned int ipg_div; > + unsigned int adc_period; > + unsigned int debounce_cnt; > + unsigned int settling_cnt; > + int itemct; > + int ret; > + > + regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr); > + ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr)); > + adc_period = USEC_PER_SEC * ipg_div * 2 + 2; > + adc_period /= clk_get_rate(priv->clk) / 1000 + 1; > + debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1; > + settling_cnt = DIV_ROUND_UP(priv->settling_time, adc_period * 8) - 1; > + > + /* Reset */ > + regmap_write(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST, 0); > + > + /* up to 128 * 8 ADC clocks are possible */ > + if (debounce_cnt > 127) > + debounce_cnt = 127; > + > + /* up to 255 * 8 ADC clocks are possible */ > + if (settling_cnt > 255) > + settling_cnt = 255; > + > + ret = imx25_setup_queue_4wire(priv, settling_cnt, &itemct); > + if (ret) > + return ret; > + > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_LITEMID_MASK | MX25_ADCQ_CR_WMRK_MASK, > + MX25_ADCQ_CR_LITEMID(itemct - 1) | > + MX25_ADCQ_CR_WMRK(priv->expected_samples - 1)); > + > + /* setup debounce count */ > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, > + MX25_TGCR_PDBTIME_MASK, > + MX25_TGCR_PDBTIME(debounce_cnt)); > + > + /* enable debounce */ > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN, > + MX25_TGCR_PDBEN); > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN, > + MX25_TGCR_PDEN); > + > + /* enable the engine on demand */ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_MASK, > + MX25_ADCQ_CR_QSM_FQS); > + > + /* Enable repeat and repeat wait */ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_RPT | MX25_ADCQ_CR_RWAIT_MASK, > + MX25_ADCQ_CR_RPT | > + MX25_ADCQ_CR_RWAIT(MX25_TSC_REPEAT_WAIT)); > + > + mx25_tcq_re_enable_touch_detection(priv); > + > + return 0; > +} > + > +static int mx25_tcq_parse_dt(struct platform_device *pdev, > + struct mx25_tcq_priv *priv) > +{ > + struct device_node *np = pdev->dev.of_node; > + u32 wires; > + int ret; > + > + /* Setup defaults */ > + priv->pen_threshold = 500; > + priv->sample_count = 3; > + priv->pen_debounce = 1000000; > + priv->settling_time = 250000; > + > + ret = of_property_read_u32(np, "fsl,wires", &wires); > + if (ret) { > + dev_err(&pdev->dev, "Failed to find fsl,wires properties\n"); > + return ret; > + } > + > + if (wires == 4) { > + priv->mode = MX25_TS_4WIRE; > + } else { > + dev_err(&pdev->dev, "%u-wire mode not supported\n", wires); > + return -EINVAL; > + } > + > + /* These are optional, we don't care about the return values */ > + of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold); > + of_property_read_u32(np, "fsl,settling-time", &priv->settling_time); > + of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce); > + > + return 0; > +} > + > +static int mx25_tcq_open(struct input_dev *idev) > +{ > + struct device *dev = &idev->dev; > + struct mx25_tcq_priv *priv = dev_get_drvdata(dev); > + int ret; > + > + ret = clk_prepare_enable(priv->clk); > + if (ret) { > + dev_err(dev, "Failed to enable ipg clock\n"); > + return ret; > + } > + > + ret = mx25_tcq_init(priv); > + if (ret) { > + dev_err(dev, "Failed to init tcq\n"); > + clk_disable_unprepare(priv->clk); > + return ret; > + } > + > + return 0; > +} > + > +static void mx25_tcq_close(struct input_dev *idev) > +{ > + struct mx25_tcq_priv *priv = input_get_drvdata(idev); > + > + mx25_tcq_force_queue_stop(priv); > + mx25_tcq_disable_touch_irq(priv); > + mx25_tcq_disable_fifo_irq(priv); > + clk_disable_unprepare(priv->clk); > +} > + > +static int mx25_tcq_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct input_dev *idev; > + struct mx25_tcq_priv *priv; > + struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent); > + struct resource *res; > + void __iomem *mem; > + int ret; Personal preference: can we call variables that hold error codes and not returned in success path (i.e. when we do explicit "return 0:' for success) be called "error"? > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + mem = devm_ioremap_resource(dev, res); > + if (!mem) devm_ioremap_resource() returns ERR_PTR-encoded pointer, you should not test it for NULL bit rather for IS_ERR. > + return -ENOMEM; > + > + ret = mx25_tcq_parse_dt(pdev, priv); > + if (ret) > + return ret; > + > + priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig); > + if (IS_ERR(priv->regs)) { > + dev_err(dev, "Failed to initialize regmap\n"); > + return PTR_ERR(priv->regs); > + } > + > + priv->irq = platform_get_irq(pdev, 0); > + if (priv->irq <= 0) { > + dev_err(dev, "Failed to get IRQ\n"); > + return priv->irq; > + } > + > + idev = devm_input_allocate_device(dev); > + if (!idev) { > + dev_err(dev, "Failed to allocate input device\n"); > + return -ENOMEM; > + } > + > + idev->name = mx25_tcq_name; > + idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); > + idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); Replace the 2 lines above with: input_set_capability(idev, EV_BTN_TOUCH); > + input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); > + input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); > + > + idev->id.bustype = BUS_HOST; > + idev->open = mx25_tcq_open; > + idev->close = mx25_tcq_close; > + > + priv->idev = idev; > + input_set_drvdata(idev, priv); > + > + priv->core_regs = tsadc->regs; > + if (!priv->core_regs) > + return -EINVAL; > + > + priv->clk = tsadc->clk; > + if (!priv->clk) > + return -EINVAL; > + > + platform_set_drvdata(pdev, priv); > + > + ret = input_register_device(idev); > + if (ret) { > + dev_err(dev, "Failed to register input device\n"); > + return ret; > + } > + > + ret = devm_request_threaded_irq(dev, priv->irq, mx25_tcq_irq, > + mx25_tcq_irq_thread, IRQF_ONESHOT, > + pdev->name, priv); > + if (ret) { > + dev_err(dev, "Failed requesting IRQ\n"); > + return ret; > + } Is it possible that we enable interrupt generation in the controller (in mx25_tcq_open) before we request IRQ and then (if someone touches the screen) we'll get a spurious IRQ? I'd rather we swapped devm_request_threaded_irq() and input_register_device(): it is perfectly safe to use (send events) to allocated but not registered input device. > + > + return 0; > +} > + > +static struct platform_driver mx25_tcq_driver = { > + .driver = { > + .name = "mx25-tcq", > + .of_match_table = mx25_tcq_ids, > + }, > + .probe = mx25_tcq_probe, > +}; > +module_platform_driver(mx25_tcq_driver); > + > +MODULE_DESCRIPTION("TS input driver for Freescale mx25"); > +MODULE_AUTHOR("Markus Pargmann "); > +MODULE_LICENSE("GPL v2"); > -- > 2.6.1 > Thanks. -- Dmitry From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 17 Nov 2015 10:17:20 -0800 From: Dmitry Torokhov To: Markus Pargmann Cc: Shawn Guo , Jonathan Cameron , Lee Jones , Denis Carikli , Eric =?iso-8859-1?Q?B=E9nard?= , Sascha Hauer , devicetree@vger.kernel.org, linux-input@vger.kernel.org, linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Hartmut Knaack , Fabio Estevam , Juergen Borleis Subject: Re: [PATCH v8 6/8] input: touchscreen: imx25 tcq driver Message-ID: <20151117181720.GC29423@dtor-ws> References: <1447675269-8831-1-git-send-email-mpa@pengutronix.de> <1447675269-8831-7-git-send-email-mpa@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1447675269-8831-7-git-send-email-mpa@pengutronix.de> List-ID: On Mon, Nov 16, 2015 at 01:01:07PM +0100, Markus Pargmann wrote: > This is a driver for the imx25 ADC/TSC module. It controls the > touchscreen conversion queue and creates a touchscreen input device. > The driver currently only supports 4 wire touchscreens. The driver uses > a simple conversion queue of precharge, touch detection, X measurement, > Y measurement, precharge and another touch detection. > > This driver uses the regmap from the parent to setup some touch specific > settings in the core driver and setup a idle configuration with touch > detection. > > Signed-off-by: Markus Pargmann > Signed-off-by: Denis Carikli > > [fix clock's period calculation] > [fix calculation of the 'settling' value] > Signed-off-by: Juergen Borleis > --- > > Notes: > Changes in v7: > - Moved clk_prepare_enable() and mx25_tcq_init() into mx25_tcq_open(). This > was done to be able to use devm_request_threaded_irq(). > - Cleanup of the probe function through above change > - Removed mx25_tcq_remove(), not necessary now > > drivers/input/touchscreen/Kconfig | 6 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/fsl-imx25-tcq.c | 600 ++++++++++++++++++++++++++++++ > 3 files changed, 607 insertions(+) > create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index ae33da7ab51f..b44651d33080 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -811,6 +811,12 @@ config TOUCHSCREEN_USB_COMPOSITE > To compile this driver as a module, choose M here: the > module will be called usbtouchscreen. > > +config TOUCHSCREEN_MX25 > + tristate "Freescale i.MX25 touchscreen input driver" > + depends on MFD_MX25_TSADC > + help > + Enable support for touchscreen connected to your i.MX25. > + To compile this driver as a module... > config TOUCHSCREEN_MC13783 > tristate "Freescale MC13783 touchscreen input driver" > depends on MFD_MC13XXX > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > index cbaa6abb08da..77a2ac54101a 100644 > --- a/drivers/input/touchscreen/Makefile > +++ b/drivers/input/touchscreen/Makefile > @@ -45,6 +45,7 @@ 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-$(CONFIG_TOUCHSCREEN_MX25) += fsl-imx25-tcq.o > obj-$(CONFIG_TOUCHSCREEN_MC13783) += mc13783_ts.o > obj-$(CONFIG_TOUCHSCREEN_MCS5000) += mcs5000_ts.o > obj-$(CONFIG_TOUCHSCREEN_MIGOR) += migor_ts.o > diff --git a/drivers/input/touchscreen/fsl-imx25-tcq.c b/drivers/input/touchscreen/fsl-imx25-tcq.c > new file mode 100644 > index 000000000000..c833cd814972 > --- /dev/null > +++ b/drivers/input/touchscreen/fsl-imx25-tcq.c > @@ -0,0 +1,600 @@ > +/* > + * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann > + * > + * 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. > + * > + * Based on driver from 2011: > + * Juergen Beisert, Pengutronix > + * > + * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue) > + * connected to the imx25 ADC. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +static const char mx25_tcq_name[] = "mx25-tcq"; > + > +enum mx25_tcq_mode { > + MX25_TS_4WIRE, > +}; > + > +struct mx25_tcq_priv { > + struct regmap *regs; > + struct regmap *core_regs; > + struct input_dev *idev; > + enum mx25_tcq_mode mode; > + unsigned int pen_threshold; > + unsigned int sample_count; > + unsigned int expected_samples; > + unsigned int pen_debounce; > + unsigned int settling_time; > + struct clk *clk; > + int irq; > +}; > + > +static struct regmap_config mx25_tcq_regconfig = { > + .fast_io = true, > + .max_register = 0x5c, > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +static const struct of_device_id mx25_tcq_ids[] = { > + { .compatible = "fsl,imx25-tcq", }, > + { /* Sentinel */ } > +}; > + > +#define TSC_4WIRE_PRE_INDEX 0 > +#define TSC_4WIRE_X_INDEX 1 > +#define TSC_4WIRE_Y_INDEX 2 > +#define TSC_4WIRE_POST_INDEX 3 > +#define TSC_4WIRE_LEAVE 4 > + > +#define MX25_TSC_DEF_THRESHOLD 80 > +#define TSC_MAX_SAMPLES 16 > + > +#define MX25_TSC_REPEAT_WAIT 14 > + > +enum mx25_adc_configurations { > + MX25_CFG_PRECHARGE = 0, > + MX25_CFG_TOUCH_DETECT, > + MX25_CFG_X_MEASUREMENT, > + MX25_CFG_Y_MEASUREMENT, > +}; > + > +#define MX25_PRECHARGE_VALUE (\ > + MX25_ADCQ_CFG_YPLL_OFF | \ > + MX25_ADCQ_CFG_XNUR_OFF | \ > + MX25_ADCQ_CFG_XPUL_HIGH | \ > + MX25_ADCQ_CFG_REFP_INT | \ > + MX25_ADCQ_CFG_IN_XP | \ > + MX25_ADCQ_CFG_REFN_NGND2 | \ > + MX25_ADCQ_CFG_IGS) > + > +#define MX25_TOUCH_DETECT_VALUE (\ > + MX25_ADCQ_CFG_YNLR | \ > + MX25_ADCQ_CFG_YPLL_OFF | \ > + MX25_ADCQ_CFG_XNUR_OFF | \ > + MX25_ADCQ_CFG_XPUL_OFF | \ > + MX25_ADCQ_CFG_REFP_INT | \ > + MX25_ADCQ_CFG_IN_XP | \ > + MX25_ADCQ_CFG_REFN_NGND2 | \ > + MX25_ADCQ_CFG_PENIACK) > + > +static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv, > + unsigned int settling_cnt) > +{ > + u32 precharge_cfg = > + MX25_PRECHARGE_VALUE | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt); > + u32 touch_detect_cfg = > + MX25_TOUCH_DETECT_VALUE | > + MX25_ADCQ_CFG_NOS(1) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt); > + > + regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg); > + > + /* PRECHARGE */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE), > + precharge_cfg); > + > + /* TOUCH_DETECT */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT), > + touch_detect_cfg); > + > + /* X Measurement */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT), > + MX25_ADCQ_CFG_YPLL_OFF | > + MX25_ADCQ_CFG_XNUR_LOW | > + MX25_ADCQ_CFG_XPUL_HIGH | > + MX25_ADCQ_CFG_REFP_XP | > + MX25_ADCQ_CFG_IN_YP | > + MX25_ADCQ_CFG_REFN_XN | > + MX25_ADCQ_CFG_NOS(priv->sample_count) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt)); > + > + /* Y Measurement */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT), > + MX25_ADCQ_CFG_YNLR | > + MX25_ADCQ_CFG_YPLL_HIGH | > + MX25_ADCQ_CFG_XNUR_OFF | > + MX25_ADCQ_CFG_XPUL_OFF | > + MX25_ADCQ_CFG_REFP_YP | > + MX25_ADCQ_CFG_IN_XP | > + MX25_ADCQ_CFG_REFN_YN | > + MX25_ADCQ_CFG_NOS(priv->sample_count) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt)); > + > + /* Enable the touch detection right now */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg | > + MX25_ADCQ_CFG_IGS); > +} > + > +static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv, > + unsigned settling_cnt, int *items) > +{ > + imx25_setup_queue_cfgs(priv, settling_cnt); > + > + /* Setup the conversion queue */ > + regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0, > + MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) | > + MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) | > + MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) | > + MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) | > + MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) | > + MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT)); > + > + /* > + * We measure X/Y with 'sample_count' number of samples and execute a > + * touch detection twice, with 1 sample each > + */ > + priv->expected_samples = priv->sample_count * 2 + 2; > + *items = 6; > + > + return 0; > +} > + > +static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, > + MX25_ADCQ_CR_PDMSK); > +} > + > +static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0); > +} > + > +static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, > + MX25_ADCQ_MR_FDRY_IRQ); > +} > + > +static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0); > +} > + > +static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_FQS, > + MX25_ADCQ_CR_FQS); > +} > + > +static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_FQS, 0); > +} > + > +static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv) > +{ > + u32 tcqcr; > + > + regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, > + MX25_ADCQ_CR_FRST); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, 0); > + regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr); > +} > + > +static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv) > +{ > + /* stop the queue from looping */ > + mx25_tcq_force_queue_stop(priv); > + > + /* for a clean touch detection, preload the X plane */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE); > + > + /* waste some time now to pre-load the X plate to high voltage */ > + mx25_tcq_fifo_reset(priv); > + > + /* re-enable the detection right now */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, > + MX25_TOUCH_DETECT_VALUE | MX25_ADCQ_CFG_IGS); > + > + regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD, > + MX25_ADCQ_SR_PD); > + > + /* enable the pen down event to be a source for the interrupt */ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0); > + > + /* lets fire the next IRQ if someone touches the touchscreen */ > + mx25_tcq_enable_touch_irq(priv); > +} > + > +static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv, Why not void? What callers are supposed to do with the value? > + u32 *sample_buf, > + unsigned int samples) > +{ > + unsigned int x_pos = 0; > + unsigned int y_pos = 0; > + unsigned int touch_pre = 0; > + unsigned int touch_post = 0; > + unsigned int i; > + int ret = 0; > + > + for (i = 0; i < samples; i++) { > + unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]); > + unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]); > + > + switch (index) { > + case 1: > + touch_pre = val; > + break; > + case 2: > + x_pos = val; > + break; > + case 3: > + y_pos = val; > + break; > + case 5: > + touch_post = val; > + break; > + default: > + ret = -EINVAL; > + break; > + } > + } > + > + if (ret == 0 && samples != 0) { Where do we set ret to anything other than 0? > + /* > + * only if both touch measures are below a threshold, > + * the position is valid > + */ > + if (touch_pre < priv->pen_threshold && > + touch_post < priv->pen_threshold) { > + /* valid samples, generate a report */ > + x_pos /= priv->sample_count; > + y_pos /= priv->sample_count; > + input_report_abs(priv->idev, ABS_X, x_pos); > + input_report_abs(priv->idev, ABS_Y, y_pos); > + input_report_key(priv->idev, BTN_TOUCH, 1); > + input_sync(priv->idev); > + > + /* get next sample */ > + mx25_tcq_enable_fifo_irq(priv); > + } else if (touch_pre >= priv->pen_threshold && > + touch_post >= priv->pen_threshold) { > + /* > + * if both samples are invalid, > + * generate a release report > + */ > + input_report_key(priv->idev, BTN_TOUCH, 0); > + input_sync(priv->idev); > + mx25_tcq_re_enable_touch_detection(priv); > + } else { > + /* > + * if only one of both touch measurements are > + * below the threshold, still some bouncing > + * happens. Take additional samples in this > + * case to be sure > + */ > + mx25_tcq_enable_fifo_irq(priv); > + } > + } > + > + return ret; > +} > + > +static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id) > +{ > + struct mx25_tcq_priv *priv = dev_id; > + u32 sample_buf[TSC_MAX_SAMPLES]; > + unsigned int samples = 0; > + > + /* read all samples */ > + while (1) { > + u32 stats; > + > + regmap_read(priv->regs, MX25_ADCQ_SR, &stats); > + if (stats & MX25_ADCQ_SR_EMPT) > + break; > + > + if (samples < TSC_MAX_SAMPLES) { > + regmap_read(priv->regs, MX25_ADCQ_FIFO, > + &sample_buf[samples]); > + ++samples; > + } else { > + u32 discarded; > + /* discard samples */ > + regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded); > + } > + } > + > + mx25_tcq_create_event_for_4wire(priv, sample_buf, samples); > + > + return IRQ_HANDLED; > +} > + > +static irqreturn_t mx25_tcq_irq(int irq, void *dev_id) > +{ > + struct mx25_tcq_priv *priv = dev_id; > + u32 stat; > + int ret = IRQ_HANDLED; > + > + regmap_read(priv->regs, MX25_ADCQ_SR, &stat); Is there any concern that these reads will fail? > + > + if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR)) > + mx25_tcq_fifo_reset(priv); > + > + if (stat & MX25_ADCQ_SR_PD) { > + mx25_tcq_disable_touch_irq(priv); > + mx25_tcq_force_queue_start(priv); > + mx25_tcq_enable_fifo_irq(priv); > + } > + > + if (stat & MX25_ADCQ_SR_FDRY) { > + mx25_tcq_disable_fifo_irq(priv); > + ret = IRQ_WAKE_THREAD; > + } > + > + regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR | > + MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | > + MX25_ADCQ_SR_PD | MX25_ADCQ_SR_EOQ, > + MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | > + MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD | > + MX25_ADCQ_SR_EOQ); > + > + return ret; > +} > + > +/* configure the statemachine for a 4-wire touchscreen */ > +static int mx25_tcq_init(struct mx25_tcq_priv *priv) > +{ > + u32 tgcr; > + unsigned int ipg_div; > + unsigned int adc_period; > + unsigned int debounce_cnt; > + unsigned int settling_cnt; > + int itemct; > + int ret; > + > + regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr); > + ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr)); > + adc_period = USEC_PER_SEC * ipg_div * 2 + 2; > + adc_period /= clk_get_rate(priv->clk) / 1000 + 1; > + debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1; > + settling_cnt = DIV_ROUND_UP(priv->settling_time, adc_period * 8) - 1; > + > + /* Reset */ > + regmap_write(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST, 0); > + > + /* up to 128 * 8 ADC clocks are possible */ > + if (debounce_cnt > 127) > + debounce_cnt = 127; > + > + /* up to 255 * 8 ADC clocks are possible */ > + if (settling_cnt > 255) > + settling_cnt = 255; > + > + ret = imx25_setup_queue_4wire(priv, settling_cnt, &itemct); > + if (ret) > + return ret; > + > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_LITEMID_MASK | MX25_ADCQ_CR_WMRK_MASK, > + MX25_ADCQ_CR_LITEMID(itemct - 1) | > + MX25_ADCQ_CR_WMRK(priv->expected_samples - 1)); > + > + /* setup debounce count */ > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, > + MX25_TGCR_PDBTIME_MASK, > + MX25_TGCR_PDBTIME(debounce_cnt)); > + > + /* enable debounce */ > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN, > + MX25_TGCR_PDBEN); > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN, > + MX25_TGCR_PDEN); > + > + /* enable the engine on demand */ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_MASK, > + MX25_ADCQ_CR_QSM_FQS); > + > + /* Enable repeat and repeat wait */ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_RPT | MX25_ADCQ_CR_RWAIT_MASK, > + MX25_ADCQ_CR_RPT | > + MX25_ADCQ_CR_RWAIT(MX25_TSC_REPEAT_WAIT)); > + > + mx25_tcq_re_enable_touch_detection(priv); > + > + return 0; > +} > + > +static int mx25_tcq_parse_dt(struct platform_device *pdev, > + struct mx25_tcq_priv *priv) > +{ > + struct device_node *np = pdev->dev.of_node; > + u32 wires; > + int ret; > + > + /* Setup defaults */ > + priv->pen_threshold = 500; > + priv->sample_count = 3; > + priv->pen_debounce = 1000000; > + priv->settling_time = 250000; > + > + ret = of_property_read_u32(np, "fsl,wires", &wires); > + if (ret) { > + dev_err(&pdev->dev, "Failed to find fsl,wires properties\n"); > + return ret; > + } > + > + if (wires == 4) { > + priv->mode = MX25_TS_4WIRE; > + } else { > + dev_err(&pdev->dev, "%u-wire mode not supported\n", wires); > + return -EINVAL; > + } > + > + /* These are optional, we don't care about the return values */ > + of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold); > + of_property_read_u32(np, "fsl,settling-time", &priv->settling_time); > + of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce); > + > + return 0; > +} > + > +static int mx25_tcq_open(struct input_dev *idev) > +{ > + struct device *dev = &idev->dev; > + struct mx25_tcq_priv *priv = dev_get_drvdata(dev); > + int ret; > + > + ret = clk_prepare_enable(priv->clk); > + if (ret) { > + dev_err(dev, "Failed to enable ipg clock\n"); > + return ret; > + } > + > + ret = mx25_tcq_init(priv); > + if (ret) { > + dev_err(dev, "Failed to init tcq\n"); > + clk_disable_unprepare(priv->clk); > + return ret; > + } > + > + return 0; > +} > + > +static void mx25_tcq_close(struct input_dev *idev) > +{ > + struct mx25_tcq_priv *priv = input_get_drvdata(idev); > + > + mx25_tcq_force_queue_stop(priv); > + mx25_tcq_disable_touch_irq(priv); > + mx25_tcq_disable_fifo_irq(priv); > + clk_disable_unprepare(priv->clk); > +} > + > +static int mx25_tcq_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct input_dev *idev; > + struct mx25_tcq_priv *priv; > + struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent); > + struct resource *res; > + void __iomem *mem; > + int ret; Personal preference: can we call variables that hold error codes and not returned in success path (i.e. when we do explicit "return 0:' for success) be called "error"? > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + mem = devm_ioremap_resource(dev, res); > + if (!mem) devm_ioremap_resource() returns ERR_PTR-encoded pointer, you should not test it for NULL bit rather for IS_ERR. > + return -ENOMEM; > + > + ret = mx25_tcq_parse_dt(pdev, priv); > + if (ret) > + return ret; > + > + priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig); > + if (IS_ERR(priv->regs)) { > + dev_err(dev, "Failed to initialize regmap\n"); > + return PTR_ERR(priv->regs); > + } > + > + priv->irq = platform_get_irq(pdev, 0); > + if (priv->irq <= 0) { > + dev_err(dev, "Failed to get IRQ\n"); > + return priv->irq; > + } > + > + idev = devm_input_allocate_device(dev); > + if (!idev) { > + dev_err(dev, "Failed to allocate input device\n"); > + return -ENOMEM; > + } > + > + idev->name = mx25_tcq_name; > + idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); > + idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); Replace the 2 lines above with: input_set_capability(idev, EV_BTN_TOUCH); > + input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); > + input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); > + > + idev->id.bustype = BUS_HOST; > + idev->open = mx25_tcq_open; > + idev->close = mx25_tcq_close; > + > + priv->idev = idev; > + input_set_drvdata(idev, priv); > + > + priv->core_regs = tsadc->regs; > + if (!priv->core_regs) > + return -EINVAL; > + > + priv->clk = tsadc->clk; > + if (!priv->clk) > + return -EINVAL; > + > + platform_set_drvdata(pdev, priv); > + > + ret = input_register_device(idev); > + if (ret) { > + dev_err(dev, "Failed to register input device\n"); > + return ret; > + } > + > + ret = devm_request_threaded_irq(dev, priv->irq, mx25_tcq_irq, > + mx25_tcq_irq_thread, IRQF_ONESHOT, > + pdev->name, priv); > + if (ret) { > + dev_err(dev, "Failed requesting IRQ\n"); > + return ret; > + } Is it possible that we enable interrupt generation in the controller (in mx25_tcq_open) before we request IRQ and then (if someone touches the screen) we'll get a spurious IRQ? I'd rather we swapped devm_request_threaded_irq() and input_register_device(): it is perfectly safe to use (send events) to allocated but not registered input device. > + > + return 0; > +} > + > +static struct platform_driver mx25_tcq_driver = { > + .driver = { > + .name = "mx25-tcq", > + .of_match_table = mx25_tcq_ids, > + }, > + .probe = mx25_tcq_probe, > +}; > +module_platform_driver(mx25_tcq_driver); > + > +MODULE_DESCRIPTION("TS input driver for Freescale mx25"); > +MODULE_AUTHOR("Markus Pargmann "); > +MODULE_LICENSE("GPL v2"); > -- > 2.6.1 > Thanks. -- Dmitry From mboxrd@z Thu Jan 1 00:00:00 1970 From: dmitry.torokhov@gmail.com (Dmitry Torokhov) Date: Tue, 17 Nov 2015 10:17:20 -0800 Subject: [PATCH v8 6/8] input: touchscreen: imx25 tcq driver In-Reply-To: <1447675269-8831-7-git-send-email-mpa@pengutronix.de> References: <1447675269-8831-1-git-send-email-mpa@pengutronix.de> <1447675269-8831-7-git-send-email-mpa@pengutronix.de> Message-ID: <20151117181720.GC29423@dtor-ws> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Nov 16, 2015 at 01:01:07PM +0100, Markus Pargmann wrote: > This is a driver for the imx25 ADC/TSC module. It controls the > touchscreen conversion queue and creates a touchscreen input device. > The driver currently only supports 4 wire touchscreens. The driver uses > a simple conversion queue of precharge, touch detection, X measurement, > Y measurement, precharge and another touch detection. > > This driver uses the regmap from the parent to setup some touch specific > settings in the core driver and setup a idle configuration with touch > detection. > > Signed-off-by: Markus Pargmann > Signed-off-by: Denis Carikli > > [fix clock's period calculation] > [fix calculation of the 'settling' value] > Signed-off-by: Juergen Borleis > --- > > Notes: > Changes in v7: > - Moved clk_prepare_enable() and mx25_tcq_init() into mx25_tcq_open(). This > was done to be able to use devm_request_threaded_irq(). > - Cleanup of the probe function through above change > - Removed mx25_tcq_remove(), not necessary now > > drivers/input/touchscreen/Kconfig | 6 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/fsl-imx25-tcq.c | 600 ++++++++++++++++++++++++++++++ > 3 files changed, 607 insertions(+) > create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index ae33da7ab51f..b44651d33080 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -811,6 +811,12 @@ config TOUCHSCREEN_USB_COMPOSITE > To compile this driver as a module, choose M here: the > module will be called usbtouchscreen. > > +config TOUCHSCREEN_MX25 > + tristate "Freescale i.MX25 touchscreen input driver" > + depends on MFD_MX25_TSADC > + help > + Enable support for touchscreen connected to your i.MX25. > + To compile this driver as a module... > config TOUCHSCREEN_MC13783 > tristate "Freescale MC13783 touchscreen input driver" > depends on MFD_MC13XXX > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > index cbaa6abb08da..77a2ac54101a 100644 > --- a/drivers/input/touchscreen/Makefile > +++ b/drivers/input/touchscreen/Makefile > @@ -45,6 +45,7 @@ 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-$(CONFIG_TOUCHSCREEN_MX25) += fsl-imx25-tcq.o > obj-$(CONFIG_TOUCHSCREEN_MC13783) += mc13783_ts.o > obj-$(CONFIG_TOUCHSCREEN_MCS5000) += mcs5000_ts.o > obj-$(CONFIG_TOUCHSCREEN_MIGOR) += migor_ts.o > diff --git a/drivers/input/touchscreen/fsl-imx25-tcq.c b/drivers/input/touchscreen/fsl-imx25-tcq.c > new file mode 100644 > index 000000000000..c833cd814972 > --- /dev/null > +++ b/drivers/input/touchscreen/fsl-imx25-tcq.c > @@ -0,0 +1,600 @@ > +/* > + * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann > + * > + * 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. > + * > + * Based on driver from 2011: > + * Juergen Beisert, Pengutronix > + * > + * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue) > + * connected to the imx25 ADC. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +static const char mx25_tcq_name[] = "mx25-tcq"; > + > +enum mx25_tcq_mode { > + MX25_TS_4WIRE, > +}; > + > +struct mx25_tcq_priv { > + struct regmap *regs; > + struct regmap *core_regs; > + struct input_dev *idev; > + enum mx25_tcq_mode mode; > + unsigned int pen_threshold; > + unsigned int sample_count; > + unsigned int expected_samples; > + unsigned int pen_debounce; > + unsigned int settling_time; > + struct clk *clk; > + int irq; > +}; > + > +static struct regmap_config mx25_tcq_regconfig = { > + .fast_io = true, > + .max_register = 0x5c, > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +static const struct of_device_id mx25_tcq_ids[] = { > + { .compatible = "fsl,imx25-tcq", }, > + { /* Sentinel */ } > +}; > + > +#define TSC_4WIRE_PRE_INDEX 0 > +#define TSC_4WIRE_X_INDEX 1 > +#define TSC_4WIRE_Y_INDEX 2 > +#define TSC_4WIRE_POST_INDEX 3 > +#define TSC_4WIRE_LEAVE 4 > + > +#define MX25_TSC_DEF_THRESHOLD 80 > +#define TSC_MAX_SAMPLES 16 > + > +#define MX25_TSC_REPEAT_WAIT 14 > + > +enum mx25_adc_configurations { > + MX25_CFG_PRECHARGE = 0, > + MX25_CFG_TOUCH_DETECT, > + MX25_CFG_X_MEASUREMENT, > + MX25_CFG_Y_MEASUREMENT, > +}; > + > +#define MX25_PRECHARGE_VALUE (\ > + MX25_ADCQ_CFG_YPLL_OFF | \ > + MX25_ADCQ_CFG_XNUR_OFF | \ > + MX25_ADCQ_CFG_XPUL_HIGH | \ > + MX25_ADCQ_CFG_REFP_INT | \ > + MX25_ADCQ_CFG_IN_XP | \ > + MX25_ADCQ_CFG_REFN_NGND2 | \ > + MX25_ADCQ_CFG_IGS) > + > +#define MX25_TOUCH_DETECT_VALUE (\ > + MX25_ADCQ_CFG_YNLR | \ > + MX25_ADCQ_CFG_YPLL_OFF | \ > + MX25_ADCQ_CFG_XNUR_OFF | \ > + MX25_ADCQ_CFG_XPUL_OFF | \ > + MX25_ADCQ_CFG_REFP_INT | \ > + MX25_ADCQ_CFG_IN_XP | \ > + MX25_ADCQ_CFG_REFN_NGND2 | \ > + MX25_ADCQ_CFG_PENIACK) > + > +static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv, > + unsigned int settling_cnt) > +{ > + u32 precharge_cfg = > + MX25_PRECHARGE_VALUE | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt); > + u32 touch_detect_cfg = > + MX25_TOUCH_DETECT_VALUE | > + MX25_ADCQ_CFG_NOS(1) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt); > + > + regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg); > + > + /* PRECHARGE */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE), > + precharge_cfg); > + > + /* TOUCH_DETECT */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT), > + touch_detect_cfg); > + > + /* X Measurement */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT), > + MX25_ADCQ_CFG_YPLL_OFF | > + MX25_ADCQ_CFG_XNUR_LOW | > + MX25_ADCQ_CFG_XPUL_HIGH | > + MX25_ADCQ_CFG_REFP_XP | > + MX25_ADCQ_CFG_IN_YP | > + MX25_ADCQ_CFG_REFN_XN | > + MX25_ADCQ_CFG_NOS(priv->sample_count) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt)); > + > + /* Y Measurement */ > + regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT), > + MX25_ADCQ_CFG_YNLR | > + MX25_ADCQ_CFG_YPLL_HIGH | > + MX25_ADCQ_CFG_XNUR_OFF | > + MX25_ADCQ_CFG_XPUL_OFF | > + MX25_ADCQ_CFG_REFP_YP | > + MX25_ADCQ_CFG_IN_XP | > + MX25_ADCQ_CFG_REFN_YN | > + MX25_ADCQ_CFG_NOS(priv->sample_count) | > + MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt)); > + > + /* Enable the touch detection right now */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg | > + MX25_ADCQ_CFG_IGS); > +} > + > +static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv, > + unsigned settling_cnt, int *items) > +{ > + imx25_setup_queue_cfgs(priv, settling_cnt); > + > + /* Setup the conversion queue */ > + regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0, > + MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) | > + MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) | > + MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) | > + MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) | > + MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) | > + MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT)); > + > + /* > + * We measure X/Y with 'sample_count' number of samples and execute a > + * touch detection twice, with 1 sample each > + */ > + priv->expected_samples = priv->sample_count * 2 + 2; > + *items = 6; > + > + return 0; > +} > + > +static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, > + MX25_ADCQ_CR_PDMSK); > +} > + > +static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0); > +} > + > +static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, > + MX25_ADCQ_MR_FDRY_IRQ); > +} > + > +static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0); > +} > + > +static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_FQS, > + MX25_ADCQ_CR_FQS); > +} > + > +static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv) > +{ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_FQS, 0); > +} > + > +static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv) > +{ > + u32 tcqcr; > + > + regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, > + MX25_ADCQ_CR_FRST); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, 0); > + regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr); > +} > + > +static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv) > +{ > + /* stop the queue from looping */ > + mx25_tcq_force_queue_stop(priv); > + > + /* for a clean touch detection, preload the X plane */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE); > + > + /* waste some time now to pre-load the X plate to high voltage */ > + mx25_tcq_fifo_reset(priv); > + > + /* re-enable the detection right now */ > + regmap_write(priv->core_regs, MX25_TSC_TICR, > + MX25_TOUCH_DETECT_VALUE | MX25_ADCQ_CFG_IGS); > + > + regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD, > + MX25_ADCQ_SR_PD); > + > + /* enable the pen down event to be a source for the interrupt */ > + regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0); > + > + /* lets fire the next IRQ if someone touches the touchscreen */ > + mx25_tcq_enable_touch_irq(priv); > +} > + > +static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv, Why not void? What callers are supposed to do with the value? > + u32 *sample_buf, > + unsigned int samples) > +{ > + unsigned int x_pos = 0; > + unsigned int y_pos = 0; > + unsigned int touch_pre = 0; > + unsigned int touch_post = 0; > + unsigned int i; > + int ret = 0; > + > + for (i = 0; i < samples; i++) { > + unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]); > + unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]); > + > + switch (index) { > + case 1: > + touch_pre = val; > + break; > + case 2: > + x_pos = val; > + break; > + case 3: > + y_pos = val; > + break; > + case 5: > + touch_post = val; > + break; > + default: > + ret = -EINVAL; > + break; > + } > + } > + > + if (ret == 0 && samples != 0) { Where do we set ret to anything other than 0? > + /* > + * only if both touch measures are below a threshold, > + * the position is valid > + */ > + if (touch_pre < priv->pen_threshold && > + touch_post < priv->pen_threshold) { > + /* valid samples, generate a report */ > + x_pos /= priv->sample_count; > + y_pos /= priv->sample_count; > + input_report_abs(priv->idev, ABS_X, x_pos); > + input_report_abs(priv->idev, ABS_Y, y_pos); > + input_report_key(priv->idev, BTN_TOUCH, 1); > + input_sync(priv->idev); > + > + /* get next sample */ > + mx25_tcq_enable_fifo_irq(priv); > + } else if (touch_pre >= priv->pen_threshold && > + touch_post >= priv->pen_threshold) { > + /* > + * if both samples are invalid, > + * generate a release report > + */ > + input_report_key(priv->idev, BTN_TOUCH, 0); > + input_sync(priv->idev); > + mx25_tcq_re_enable_touch_detection(priv); > + } else { > + /* > + * if only one of both touch measurements are > + * below the threshold, still some bouncing > + * happens. Take additional samples in this > + * case to be sure > + */ > + mx25_tcq_enable_fifo_irq(priv); > + } > + } > + > + return ret; > +} > + > +static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id) > +{ > + struct mx25_tcq_priv *priv = dev_id; > + u32 sample_buf[TSC_MAX_SAMPLES]; > + unsigned int samples = 0; > + > + /* read all samples */ > + while (1) { > + u32 stats; > + > + regmap_read(priv->regs, MX25_ADCQ_SR, &stats); > + if (stats & MX25_ADCQ_SR_EMPT) > + break; > + > + if (samples < TSC_MAX_SAMPLES) { > + regmap_read(priv->regs, MX25_ADCQ_FIFO, > + &sample_buf[samples]); > + ++samples; > + } else { > + u32 discarded; > + /* discard samples */ > + regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded); > + } > + } > + > + mx25_tcq_create_event_for_4wire(priv, sample_buf, samples); > + > + return IRQ_HANDLED; > +} > + > +static irqreturn_t mx25_tcq_irq(int irq, void *dev_id) > +{ > + struct mx25_tcq_priv *priv = dev_id; > + u32 stat; > + int ret = IRQ_HANDLED; > + > + regmap_read(priv->regs, MX25_ADCQ_SR, &stat); Is there any concern that these reads will fail? > + > + if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR)) > + mx25_tcq_fifo_reset(priv); > + > + if (stat & MX25_ADCQ_SR_PD) { > + mx25_tcq_disable_touch_irq(priv); > + mx25_tcq_force_queue_start(priv); > + mx25_tcq_enable_fifo_irq(priv); > + } > + > + if (stat & MX25_ADCQ_SR_FDRY) { > + mx25_tcq_disable_fifo_irq(priv); > + ret = IRQ_WAKE_THREAD; > + } > + > + regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR | > + MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | > + MX25_ADCQ_SR_PD | MX25_ADCQ_SR_EOQ, > + MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | > + MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD | > + MX25_ADCQ_SR_EOQ); > + > + return ret; > +} > + > +/* configure the statemachine for a 4-wire touchscreen */ > +static int mx25_tcq_init(struct mx25_tcq_priv *priv) > +{ > + u32 tgcr; > + unsigned int ipg_div; > + unsigned int adc_period; > + unsigned int debounce_cnt; > + unsigned int settling_cnt; > + int itemct; > + int ret; > + > + regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr); > + ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr)); > + adc_period = USEC_PER_SEC * ipg_div * 2 + 2; > + adc_period /= clk_get_rate(priv->clk) / 1000 + 1; > + debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1; > + settling_cnt = DIV_ROUND_UP(priv->settling_time, adc_period * 8) - 1; > + > + /* Reset */ > + regmap_write(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST); > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST, 0); > + > + /* up to 128 * 8 ADC clocks are possible */ > + if (debounce_cnt > 127) > + debounce_cnt = 127; > + > + /* up to 255 * 8 ADC clocks are possible */ > + if (settling_cnt > 255) > + settling_cnt = 255; > + > + ret = imx25_setup_queue_4wire(priv, settling_cnt, &itemct); > + if (ret) > + return ret; > + > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_LITEMID_MASK | MX25_ADCQ_CR_WMRK_MASK, > + MX25_ADCQ_CR_LITEMID(itemct - 1) | > + MX25_ADCQ_CR_WMRK(priv->expected_samples - 1)); > + > + /* setup debounce count */ > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, > + MX25_TGCR_PDBTIME_MASK, > + MX25_TGCR_PDBTIME(debounce_cnt)); > + > + /* enable debounce */ > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN, > + MX25_TGCR_PDBEN); > + regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN, > + MX25_TGCR_PDEN); > + > + /* enable the engine on demand */ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_MASK, > + MX25_ADCQ_CR_QSM_FQS); > + > + /* Enable repeat and repeat wait */ > + regmap_update_bits(priv->regs, MX25_ADCQ_CR, > + MX25_ADCQ_CR_RPT | MX25_ADCQ_CR_RWAIT_MASK, > + MX25_ADCQ_CR_RPT | > + MX25_ADCQ_CR_RWAIT(MX25_TSC_REPEAT_WAIT)); > + > + mx25_tcq_re_enable_touch_detection(priv); > + > + return 0; > +} > + > +static int mx25_tcq_parse_dt(struct platform_device *pdev, > + struct mx25_tcq_priv *priv) > +{ > + struct device_node *np = pdev->dev.of_node; > + u32 wires; > + int ret; > + > + /* Setup defaults */ > + priv->pen_threshold = 500; > + priv->sample_count = 3; > + priv->pen_debounce = 1000000; > + priv->settling_time = 250000; > + > + ret = of_property_read_u32(np, "fsl,wires", &wires); > + if (ret) { > + dev_err(&pdev->dev, "Failed to find fsl,wires properties\n"); > + return ret; > + } > + > + if (wires == 4) { > + priv->mode = MX25_TS_4WIRE; > + } else { > + dev_err(&pdev->dev, "%u-wire mode not supported\n", wires); > + return -EINVAL; > + } > + > + /* These are optional, we don't care about the return values */ > + of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold); > + of_property_read_u32(np, "fsl,settling-time", &priv->settling_time); > + of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce); > + > + return 0; > +} > + > +static int mx25_tcq_open(struct input_dev *idev) > +{ > + struct device *dev = &idev->dev; > + struct mx25_tcq_priv *priv = dev_get_drvdata(dev); > + int ret; > + > + ret = clk_prepare_enable(priv->clk); > + if (ret) { > + dev_err(dev, "Failed to enable ipg clock\n"); > + return ret; > + } > + > + ret = mx25_tcq_init(priv); > + if (ret) { > + dev_err(dev, "Failed to init tcq\n"); > + clk_disable_unprepare(priv->clk); > + return ret; > + } > + > + return 0; > +} > + > +static void mx25_tcq_close(struct input_dev *idev) > +{ > + struct mx25_tcq_priv *priv = input_get_drvdata(idev); > + > + mx25_tcq_force_queue_stop(priv); > + mx25_tcq_disable_touch_irq(priv); > + mx25_tcq_disable_fifo_irq(priv); > + clk_disable_unprepare(priv->clk); > +} > + > +static int mx25_tcq_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct input_dev *idev; > + struct mx25_tcq_priv *priv; > + struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent); > + struct resource *res; > + void __iomem *mem; > + int ret; Personal preference: can we call variables that hold error codes and not returned in success path (i.e. when we do explicit "return 0:' for success) be called "error"? > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + mem = devm_ioremap_resource(dev, res); > + if (!mem) devm_ioremap_resource() returns ERR_PTR-encoded pointer, you should not test it for NULL bit rather for IS_ERR. > + return -ENOMEM; > + > + ret = mx25_tcq_parse_dt(pdev, priv); > + if (ret) > + return ret; > + > + priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig); > + if (IS_ERR(priv->regs)) { > + dev_err(dev, "Failed to initialize regmap\n"); > + return PTR_ERR(priv->regs); > + } > + > + priv->irq = platform_get_irq(pdev, 0); > + if (priv->irq <= 0) { > + dev_err(dev, "Failed to get IRQ\n"); > + return priv->irq; > + } > + > + idev = devm_input_allocate_device(dev); > + if (!idev) { > + dev_err(dev, "Failed to allocate input device\n"); > + return -ENOMEM; > + } > + > + idev->name = mx25_tcq_name; > + idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); > + idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); Replace the 2 lines above with: input_set_capability(idev, EV_BTN_TOUCH); > + input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); > + input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); > + > + idev->id.bustype = BUS_HOST; > + idev->open = mx25_tcq_open; > + idev->close = mx25_tcq_close; > + > + priv->idev = idev; > + input_set_drvdata(idev, priv); > + > + priv->core_regs = tsadc->regs; > + if (!priv->core_regs) > + return -EINVAL; > + > + priv->clk = tsadc->clk; > + if (!priv->clk) > + return -EINVAL; > + > + platform_set_drvdata(pdev, priv); > + > + ret = input_register_device(idev); > + if (ret) { > + dev_err(dev, "Failed to register input device\n"); > + return ret; > + } > + > + ret = devm_request_threaded_irq(dev, priv->irq, mx25_tcq_irq, > + mx25_tcq_irq_thread, IRQF_ONESHOT, > + pdev->name, priv); > + if (ret) { > + dev_err(dev, "Failed requesting IRQ\n"); > + return ret; > + } Is it possible that we enable interrupt generation in the controller (in mx25_tcq_open) before we request IRQ and then (if someone touches the screen) we'll get a spurious IRQ? I'd rather we swapped devm_request_threaded_irq() and input_register_device(): it is perfectly safe to use (send events) to allocated but not registered input device. > + > + return 0; > +} > + > +static struct platform_driver mx25_tcq_driver = { > + .driver = { > + .name = "mx25-tcq", > + .of_match_table = mx25_tcq_ids, > + }, > + .probe = mx25_tcq_probe, > +}; > +module_platform_driver(mx25_tcq_driver); > + > +MODULE_DESCRIPTION("TS input driver for Freescale mx25"); > +MODULE_AUTHOR("Markus Pargmann "); > +MODULE_LICENSE("GPL v2"); > -- > 2.6.1 > Thanks. -- Dmitry