// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc. * * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver * Based on: ads7846.c * * Bugs: Enter bugs at http://blackfin.uclinux.org/ * * History: * Copyright (c) 2005 David Brownell * Copyright (c) 2006 Nokia Corporation * Various changes: Imre Deak <imre.deak@nokia.com> * * Using code from: * - corgi_ts.c * Copyright (C) 2004-2005 Richard Purdie * - omap_ts.[hc], ads7846.h, ts_osk.c * Copyright (C) 2002 MontaVista Software * Copyright (C) 2004 Texas Instruments * Copyright (C) 2005 Dirk Behme */ #include <linux/device.h>#include <linux/delay.h>#include <linux/input.h>#include <linux/interrupt.h>#include <linux/pm.h>#include <linux/slab.h>#include <linux/spi/spi.h>#include <linux/spi/ad7877.h>#include <linux/module.h>#include <asm/irq.h> #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100) #define MAX_SPI_FREQ_HZ 20000000#define MAX_12BIT ((1<<12)-1) #define AD7877_REG_ZEROS 0#define AD7877_REG_CTRL1 1#define AD7877_REG_CTRL2 2#define AD7877_REG_ALERT 3#define AD7877_REG_AUX1HIGH 4#define AD7877_REG_AUX1LOW 5#define AD7877_REG_BAT1HIGH 6#define AD7877_REG_BAT1LOW 7#define AD7877_REG_BAT2HIGH 8#define AD7877_REG_BAT2LOW 9#define AD7877_REG_TEMP1HIGH 10#define AD7877_REG_TEMP1LOW 11#define AD7877_REG_SEQ0 12#define AD7877_REG_SEQ1 13#define AD7877_REG_DAC 14#define AD7877_REG_NONE1 15#define AD7877_REG_EXTWRITE 15#define AD7877_REG_XPLUS 16#define AD7877_REG_YPLUS 17#define AD7877_REG_Z2 18#define AD7877_REG_aux1 19#define AD7877_REG_aux2 20#define AD7877_REG_aux3 21#define AD7877_REG_bat1 22#define AD7877_REG_bat2 23#define AD7877_REG_temp1 24#define AD7877_REG_temp2 25#define AD7877_REG_Z1 26#define AD7877_REG_GPIOCTRL1 27#define AD7877_REG_GPIOCTRL2 28#define AD7877_REG_GPIODATA 29#define AD7877_REG_NONE2 30#define AD7877_REG_NONE3 31 #define AD7877_SEQ_YPLUS_BIT (1<<11)#define AD7877_SEQ_XPLUS_BIT (1<<10)#define AD7877_SEQ_Z2_BIT (1<<9)#define AD7877_SEQ_AUX1_BIT (1<<8)#define AD7877_SEQ_AUX2_BIT (1<<7)#define AD7877_SEQ_AUX3_BIT (1<<6)#define AD7877_SEQ_BAT1_BIT (1<<5)#define AD7877_SEQ_BAT2_BIT (1<<4)#define AD7877_SEQ_TEMP1_BIT (1<<3)#define AD7877_SEQ_TEMP2_BIT (1<<2)#define AD7877_SEQ_Z1_BIT (1<<1) enum { AD7877_SEQ_YPOS = 0, AD7877_SEQ_XPOS = 1, AD7877_SEQ_Z2 = 2, AD7877_SEQ_AUX1 = 3, AD7877_SEQ_AUX2 = 4, AD7877_SEQ_AUX3 = 5, AD7877_SEQ_BAT1 = 6, AD7877_SEQ_BAT2 = 7, AD7877_SEQ_TEMP1 = 8, AD7877_SEQ_TEMP2 = 9, AD7877_SEQ_Z1 = 10, AD7877_NR_SENSE = 11,}; /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */#define AD7877_DAC_CONF 0x1 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */#define AD7877_EXTW_GPIO_3_CONF 0x1C4#define AD7877_EXTW_GPIO_DATA 0x200 /* Control REG 2 */#define AD7877_TMR(x) ((x & 0x3) << 0)#define AD7877_REF(x) ((x & 0x1) << 2)#define AD7877_POL(x) ((x & 0x1) << 3)#define AD7877_FCD(x) ((x & 0x3) << 4)#define AD7877_PM(x) ((x & 0x3) << 6)#define AD7877_ACQ(x) ((x & 0x3) << 8)#define AD7877_AVG(x) ((x & 0x3) << 10) /* Control REG 1 */#define AD7877_SER (1 << 11) /* non-differential */#define AD7877_DFR (0 << 11) /* differential */ #define AD7877_MODE_NOC (0) /* Do not convert */#define AD7877_MODE_SCC (1) /* Single channel conversion */#define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */#define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */ #define AD7877_CHANADD(x) ((x&0xF)<<7)#define AD7877_READADD(x) ((x)<<2)#define AD7877_WRITEADD(x) ((x)<<12) #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \ AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \ AD7877_READADD(AD7877_REG_ ## x)) #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \ AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT) /* * Non-touchscreen sensors only use single-ended conversions. */ struct ser_req { u16 reset; u16 ref_on; u16 command; struct spi_message msg; struct spi_transfer xfer[6]; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ u16 sample ____cacheline_aligned;}; struct ad7877 { struct input_dev *input; char phys[32]; struct spi_device *spi; u16 model; u16 vref_delay_usecs; u16 x_plate_ohms; u16 pressure_max; u16 cmd_crtl1; u16 cmd_crtl2; u16 cmd_dummy; u16 dac; u8 stopacq_polarity; u8 first_conversion_delay; u8 acquisition_time; u8 averaging; u8 pen_down_acc_interval; struct spi_transfer xfer[AD7877_NR_SENSE + 2]; struct spi_message msg; struct mutex mutex; bool disabled; /* P: mutex */ bool gpio3; /* P: mutex */ bool gpio4; /* P: mutex */ spinlock_t lock; struct timer_list timer; /* P: lock */ /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;}; static bool gpio3;module_param(gpio3, bool, 0);MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3"); static int ad7877_read(struct spi_device *spi, u16 reg){ struct ser_req *req; int status, ret; req = kzalloc_obj(*req); if (!req) return -ENOMEM; spi_message_init(&req->msg); req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_READADD(reg)); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; req->xfer[0].cs_change = 1; req->xfer[1].rx_buf = &req->sample; req->xfer[1].len = 2; spi_message_add_tail(&req->xfer[0], &req->msg); spi_message_add_tail(&req->xfer[1], &req->msg); status = spi_sync(spi, &req->msg); ret = status ? : req->sample; kfree(req); return ret;} static int ad7877_write(struct spi_device *spi, u16 reg, u16 val){ struct ser_req *req; int status; req = kzalloc_obj(*req); if (!req) return -ENOMEM; spi_message_init(&req->msg); req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT)); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; spi_message_add_tail(&req->xfer[0], &req->msg); status = spi_sync(spi, &req->msg); kfree(req); return status;} static int ad7877_read_adc(struct spi_device *spi, unsigned command){ struct ad7877 *ts = spi_get_drvdata(spi); struct ser_req *req; int status; int sample; int i; req = kzalloc_obj(*req); if (!req) return -ENOMEM; spi_message_init(&req->msg); /* activate reference, so it has time to settle; */ req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) | AD7877_POL(ts->stopacq_polarity) | AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) | AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0); req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC; req->command = (u16) command; req->xfer[0].tx_buf = &req->reset; req->xfer[0].len = 2; req->xfer[0].cs_change = 1; req->xfer[1].tx_buf = &req->ref_on; req->xfer[1].len = 2; req->xfer[1].delay.value = ts->vref_delay_usecs; req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; req->xfer[1].cs_change = 1; req->xfer[2].tx_buf = &req->command; req->xfer[2].len = 2; req->xfer[2].delay.value = ts->vref_delay_usecs; req->xfer[2].delay.unit = SPI_DELAY_UNIT_USECS; req->xfer[2].cs_change = 1; req->xfer[3].rx_buf = &req->sample; req->xfer[3].len = 2; req->xfer[3].cs_change = 1; req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ req->xfer[4].len = 2; req->xfer[4].cs_change = 1; req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ req->xfer[5].len = 2; /* group all the transfers together, so we can't interfere with * reading touchscreen state; disable penirq while sampling */ for (i = 0; i < 6; i++) spi_message_add_tail(&req->xfer[i], &req->msg); status = spi_sync(spi, &req->msg); sample = req->sample; kfree(req); return status ? : sample;} static int ad7877_process_data(struct ad7877 *ts){ struct input_dev *input_dev = ts->input; unsigned Rt; u16 x, y, z1, z2; x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT; y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT; z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT; z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT; /* * The samples processed here are already preprocessed by the AD7877. * The preprocessing function consists of an averaging filter. * The combination of 'first conversion delay' and averaging provides a robust solution, * discarding the spurious noise in the signal and keeping only the data of interest. * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h) * Other user-programmable conversion controls include variable acquisition time, * and first conversion delay. Up to 16 averages can be taken per conversion. */ if (likely(x && z1)) { /* compute touch pressure resistance using equation #1 */ Rt = (z2 - z1) * x * ts->x_plate_ohms; Rt /= z1; Rt = (Rt + 2047) >> 12; /* * Sample found inconsistent, pressure is beyond * the maximum. Don't report it to user space. */ if (Rt > ts->pressure_max) return -EINVAL; if (!timer_pending(&ts->timer)) input_report_key(input_dev, BTN_TOUCH, 1); input_report_abs(input_dev, ABS_X, x); input_report_abs(input_dev, ABS_Y, y); input_report_abs(input_dev, ABS_PRESSURE, Rt); input_sync(input_dev); return 0; } return -EINVAL;} static inline void ad7877_ts_event_release(struct ad7877 *ts){ struct input_dev *input_dev = ts->input; input_report_abs(input_dev, ABS_PRESSURE, 0); input_report_key(input_dev, BTN_TOUCH, 0); input_sync(input_dev);} static void ad7877_timer(struct timer_list *t){ struct ad7877 *ts = timer_container_of(ts, t, timer); guard(spinlock_irqsave)(&ts->lock); ad7877_ts_event_release(ts);} static irqreturn_t ad7877_irq(int irq, void *handle){ struct ad7877 *ts = handle; int error; error = spi_sync(ts->spi, &ts->msg); if (error) { dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); goto out; } scoped_guard(spinlock_irqsave, &ts->lock) { error = ad7877_process_data(ts); if (error) goto out; mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); } out: return IRQ_HANDLED;} static void ad7877_disable(void *data){ struct ad7877 *ts = data; guard(mutex)(&ts->mutex); if (!ts->disabled) { ts->disabled = true; disable_irq(ts->spi->irq); if (timer_delete_sync(&ts->timer)) ad7877_ts_event_release(ts); } /* * We know the chip's in lowpower mode since we always * leave it that way after every request */} static void ad7877_enable(struct ad7877 *ts){ guard(mutex)(&ts->mutex); if (ts->disabled) { ts->disabled = false; enable_irq(ts->spi->irq); }} #define SHOW(name) static ssize_t \name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \{ \ struct ad7877 *ts = dev_get_drvdata(dev); \ ssize_t v = ad7877_read_adc(ts->spi, \ AD7877_READ_CHAN(name)); \ if (v < 0) \ return v; \ return sprintf(buf, "%u\n", (unsigned) v); \} \static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); SHOW(aux1)SHOW(aux2)SHOW(aux3)SHOW(bat1)SHOW(bat2)SHOW(temp1)SHOW(temp2) static ssize_t ad7877_disable_show(struct device *dev, struct device_attribute *attr, char *buf){ struct ad7877 *ts = dev_get_drvdata(dev); return sprintf(buf, "%u\n", ts->disabled);} static ssize_t ad7877_disable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ struct ad7877 *ts = dev_get_drvdata(dev); unsigned int val; int error; error = kstrtouint(buf, 10, &val); if (error) return error; if (val) ad7877_disable(ts); else ad7877_enable(ts); return count;} static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store); static ssize_t ad7877_dac_show(struct device *dev, struct device_attribute *attr, char *buf){ struct ad7877 *ts = dev_get_drvdata(dev); return sprintf(buf, "%u\n", ts->dac);} static ssize_t ad7877_dac_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ struct ad7877 *ts = dev_get_drvdata(dev); unsigned int val;Lines 1–500 of 814. 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// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc. * * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver * Based on: ads7846.c * * Bugs: Enter bugs at http://blackfin.uclinux.org/ * * History: * Copyright (c) 2005 David Brownell * Copyright (c) 2006 Nokia Corporation * Various changes: Imre Deak <imre.deak@nokia.com> * * Using code from: * - corgi_ts.c * Copyright (C) 2004-2005 Richard Purdie * - omap_ts.[hc], ads7846.h, ts_osk.c * Copyright (C) 2002 MontaVista Software * Copyright (C) 2004 Texas Instruments * Copyright (C) 2005 Dirk Behme */ #include <linux/device.h> #include <linux/delay.h> #include <linux/input.h> #include <linux/interrupt.h> #include <linux/pm.h> #include <linux/slab.h> #include <linux/spi/spi.h> #include <linux/spi/ad7877.h> #include <linux/module.h> #include <asm/irq.h> #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100) #define MAX_SPI_FREQ_HZ 20000000 #define MAX_12BIT ((1<<12)-1) #define AD7877_REG_ZEROS 0 #define AD7877_REG_CTRL1 1 #define AD7877_REG_CTRL2 2 #define AD7877_REG_ALERT 3 #define AD7877_REG_AUX1HIGH 4 #define AD7877_REG_AUX1LOW 5 #define AD7877_REG_BAT1HIGH 6 #define AD7877_REG_BAT1LOW 7 #define AD7877_REG_BAT2HIGH 8 #define AD7877_REG_BAT2LOW 9 #define AD7877_REG_TEMP1HIGH 10 #define AD7877_REG_TEMP1LOW 11 #define AD7877_REG_SEQ0 12 #define AD7877_REG_SEQ1 13 #define AD7877_REG_DAC 14 #define AD7877_REG_NONE1 15 #define AD7877_REG_EXTWRITE 15 #define AD7877_REG_XPLUS 16 #define AD7877_REG_YPLUS 17 #define AD7877_REG_Z2 18 #define AD7877_REG_aux1 19 #define AD7877_REG_aux2 20 #define AD7877_REG_aux3 21 #define AD7877_REG_bat1 22 #define AD7877_REG_bat2 23 #define AD7877_REG_temp1 24 #define AD7877_REG_temp2 25 #define AD7877_REG_Z1 26 #define AD7877_REG_GPIOCTRL1 27 #define AD7877_REG_GPIOCTRL2 28 #define AD7877_REG_GPIODATA 29 #define AD7877_REG_NONE2 30 #define AD7877_REG_NONE3 31 #define AD7877_SEQ_YPLUS_BIT (1<<11) #define AD7877_SEQ_XPLUS_BIT (1<<10) #define AD7877_SEQ_Z2_BIT (1<<9) #define AD7877_SEQ_AUX1_BIT (1<<8) #define AD7877_SEQ_AUX2_BIT (1<<7) #define AD7877_SEQ_AUX3_BIT (1<<6) #define AD7877_SEQ_BAT1_BIT (1<<5) #define AD7877_SEQ_BAT2_BIT (1<<4) #define AD7877_SEQ_TEMP1_BIT (1<<3) #define AD7877_SEQ_TEMP2_BIT (1<<2) #define AD7877_SEQ_Z1_BIT (1<<1) enum { AD7877_SEQ_YPOS = 0, AD7877_SEQ_XPOS = 1, AD7877_SEQ_Z2 = 2, AD7877_SEQ_AUX1 = 3, AD7877_SEQ_AUX2 = 4, AD7877_SEQ_AUX3 = 5, AD7877_SEQ_BAT1 = 6, AD7877_SEQ_BAT2 = 7, AD7877_SEQ_TEMP1 = 8, AD7877_SEQ_TEMP2 = 9, AD7877_SEQ_Z1 = 10, AD7877_NR_SENSE = 11, }; /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */ #define AD7877_DAC_CONF 0x1 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */ #define AD7877_EXTW_GPIO_3_CONF 0x1C4 #define AD7877_EXTW_GPIO_DATA 0x200 /* Control REG 2 */ #define AD7877_TMR(x) ((x & 0x3) << 0) #define AD7877_REF(x) ((x & 0x1) << 2) #define AD7877_POL(x) ((x & 0x1) << 3) #define AD7877_FCD(x) ((x & 0x3) << 4) #define AD7877_PM(x) ((x & 0x3) << 6) #define AD7877_ACQ(x) ((x & 0x3) << 8) #define AD7877_AVG(x) ((x & 0x3) << 10) /* Control REG 1 */ #define AD7877_SER (1 << 11) /* non-differential */ #define AD7877_DFR (0 << 11) /* differential */ #define AD7877_MODE_NOC (0) /* Do not convert */ #define AD7877_MODE_SCC (1) /* Single channel conversion */ #define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */ #define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */ #define AD7877_CHANADD(x) ((x&0xF)<<7) #define AD7877_READADD(x) ((x)<<2) #define AD7877_WRITEADD(x) ((x)<<12) #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \ AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \ AD7877_READADD(AD7877_REG_ ## x)) #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \ AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT) /* * Non-touchscreen sensors only use single-ended conversions. */ struct ser_req { u16 reset; u16 ref_on; u16 command; struct spi_message msg; struct spi_transfer xfer[6]; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ u16 sample ____cacheline_aligned; }; struct ad7877 { struct input_dev *input; char phys[32]; struct spi_device *spi; u16 model; u16 vref_delay_usecs; u16 x_plate_ohms; u16 pressure_max; u16 cmd_crtl1; u16 cmd_crtl2; u16 cmd_dummy; u16 dac; u8 stopacq_polarity; u8 first_conversion_delay; u8 acquisition_time; u8 averaging; u8 pen_down_acc_interval; struct spi_transfer xfer[AD7877_NR_SENSE + 2]; struct spi_message msg; struct mutex mutex; bool disabled; /* P: mutex */ bool gpio3; /* P: mutex */ bool gpio4; /* P: mutex */ spinlock_t lock; struct timer_list timer; /* P: lock */ /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned; }; static bool gpio3; module_param(gpio3, bool, 0); MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3"); static int ad7877_read(struct spi_device *spi, u16 reg) { struct ser_req *req; int status, ret; req = kzalloc_obj(*req); if (!req) return -ENOMEM; spi_message_init(&req->msg); req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_READADD(reg)); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; req->xfer[0].cs_change = 1; req->xfer[1].rx_buf = &req->sample; req->xfer[1].len = 2; spi_message_add_tail(&req->xfer[0], &req->msg); spi_message_add_tail(&req->xfer[1], &req->msg); status = spi_sync(spi, &req->msg); ret = status ? : req->sample; kfree(req); return ret; } static int ad7877_write(struct spi_device *spi, u16 reg, u16 val) { struct ser_req *req; int status; req = kzalloc_obj(*req); if (!req) return -ENOMEM; spi_message_init(&req->msg); req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT)); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; spi_message_add_tail(&req->xfer[0], &req->msg); status = spi_sync(spi, &req->msg); kfree(req); return status; } static int ad7877_read_adc(struct spi_device *spi, unsigned command) { struct ad7877 *ts = spi_get_drvdata(spi); struct ser_req *req; int status; int sample; int i; req = kzalloc_obj(*req); if (!req) return -ENOMEM; spi_message_init(&req->msg); /* activate reference, so it has time to settle; */ req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) | AD7877_POL(ts->stopacq_polarity) | AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) | AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0); req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC; req->command = (u16) command; req->xfer[0].tx_buf = &req->reset; req->xfer[0].len = 2; req->xfer[0].cs_change = 1; req->xfer[1].tx_buf = &req->ref_on; req->xfer[1].len = 2; req->xfer[1].delay.value = ts->vref_delay_usecs; req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; req->xfer[1].cs_change = 1; req->xfer[2].tx_buf = &req->command; req->xfer[2].len = 2; req->xfer[2].delay.value = ts->vref_delay_usecs; req->xfer[2].delay.unit = SPI_DELAY_UNIT_USECS; req->xfer[2].cs_change = 1; req->xfer[3].rx_buf = &req->sample; req->xfer[3].len = 2; req->xfer[3].cs_change = 1; req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ req->xfer[4].len = 2; req->xfer[4].cs_change = 1; req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ req->xfer[5].len = 2; /* group all the transfers together, so we can't interfere with * reading touchscreen state; disable penirq while sampling */ for (i = 0; i < 6; i++) spi_message_add_tail(&req->xfer[i], &req->msg); status = spi_sync(spi, &req->msg); sample = req->sample; kfree(req); return status ? : sample; } static int ad7877_process_data(struct ad7877 *ts) { struct input_dev *input_dev = ts->input; unsigned Rt; u16 x, y, z1, z2; x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT; y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT; z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT; z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT; /* * The samples processed here are already preprocessed by the AD7877. * The preprocessing function consists of an averaging filter. * The combination of 'first conversion delay' and averaging provides a robust solution, * discarding the spurious noise in the signal and keeping only the data of interest. * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h) * Other user-programmable conversion controls include variable acquisition time, * and first conversion delay. Up to 16 averages can be taken per conversion. */ if (likely(x && z1)) { /* compute touch pressure resistance using equation #1 */ Rt = (z2 - z1) * x * ts->x_plate_ohms; Rt /= z1; Rt = (Rt + 2047) >> 12; /* * Sample found inconsistent, pressure is beyond * the maximum. Don't report it to user space. */ if (Rt > ts->pressure_max) return -EINVAL; if (!timer_pending(&ts->timer)) input_report_key(input_dev, BTN_TOUCH, 1); input_report_abs(input_dev, ABS_X, x); input_report_abs(input_dev, ABS_Y, y); input_report_abs(input_dev, ABS_PRESSURE, Rt); input_sync(input_dev); return 0; } return -EINVAL; } static inline void ad7877_ts_event_release(struct ad7877 *ts) { struct input_dev *input_dev = ts->input; input_report_abs(input_dev, ABS_PRESSURE, 0); input_report_key(input_dev, BTN_TOUCH, 0); input_sync(input_dev); } static void ad7877_timer(struct timer_list *t) { struct ad7877 *ts = timer_container_of(ts, t, timer); guard(spinlock_irqsave)(&ts->lock); ad7877_ts_event_release(ts); } static irqreturn_t ad7877_irq(int irq, void *handle) { struct ad7877 *ts = handle; int error; error = spi_sync(ts->spi, &ts->msg); if (error) { dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); goto out; } scoped_guard(spinlock_irqsave, &ts->lock) { error = ad7877_process_data(ts); if (error) goto out; mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); } out: return IRQ_HANDLED; } static void ad7877_disable(void *data) { struct ad7877 *ts = data; guard(mutex)(&ts->mutex); if (!ts->disabled) { ts->disabled = true; disable_irq(ts->spi->irq); if (timer_delete_sync(&ts->timer)) ad7877_ts_event_release(ts); } /* * We know the chip's in lowpower mode since we always * leave it that way after every request */ } static void ad7877_enable(struct ad7877 *ts) { guard(mutex)(&ts->mutex); if (ts->disabled) { ts->disabled = false; enable_irq(ts->spi->irq); } } #define SHOW(name) static ssize_t \ name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ { \ struct ad7877 *ts = dev_get_drvdata(dev); \ ssize_t v = ad7877_read_adc(ts->spi, \ AD7877_READ_CHAN(name)); \ if (v < 0) \ return v; \ return sprintf(buf, "%u\n", (unsigned) v); \ } \ static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); SHOW(aux1) SHOW(aux2) SHOW(aux3) SHOW(bat1) SHOW(bat2) SHOW(temp1) SHOW(temp2) static ssize_t ad7877_disable_show(struct device *dev, struct device_attribute *attr, char *buf) { struct ad7877 *ts = dev_get_drvdata(dev); return sprintf(buf, "%u\n", ts->disabled); } static ssize_t ad7877_disable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ad7877 *ts = dev_get_drvdata(dev); unsigned int val; int error; error = kstrtouint(buf, 10, &val); if (error) return error; if (val) ad7877_disable(ts); else ad7877_enable(ts); return count; } static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store); static ssize_t ad7877_dac_show(struct device *dev, struct device_attribute *attr, char *buf) { struct ad7877 *ts = dev_get_drvdata(dev); return sprintf(buf, "%u\n", ts->dac); } static ssize_t ad7877_dac_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ad7877 *ts = dev_get_drvdata(dev); unsigned int val;