| /* |
| * ADS7846 based touchscreen and sensor driver |
| * |
| * 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 |
| * |
| * 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. |
| */ |
| #include <linux/types.h> |
| #include <linux/hwmon.h> |
| #include <linux/init.h> |
| #include <linux/err.h> |
| #include <linux/sched.h> |
| #include <linux/delay.h> |
| #include <linux/input.h> |
| #include <linux/interrupt.h> |
| #include <linux/slab.h> |
| #include <linux/pm.h> |
| #include <linux/gpio.h> |
| #include <linux/spi/spi.h> |
| #include <linux/spi/ads7846.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/module.h> |
| #include <asm/irq.h> |
| |
| /* |
| * This code has been heavily tested on a Nokia 770, and lightly |
| * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). |
| * TSC2046 is just newer ads7846 silicon. |
| * Support for ads7843 tested on Atmel at91sam926x-EK. |
| * Support for ads7845 has only been stubbed in. |
| * Support for Analog Devices AD7873 and AD7843 tested. |
| * |
| * IRQ handling needs a workaround because of a shortcoming in handling |
| * edge triggered IRQs on some platforms like the OMAP1/2. These |
| * platforms don't handle the ARM lazy IRQ disabling properly, thus we |
| * have to maintain our own SW IRQ disabled status. This should be |
| * removed as soon as the affected platform's IRQ handling is fixed. |
| * |
| * App note sbaa036 talks in more detail about accurate sampling... |
| * that ought to help in situations like LCDs inducing noise (which |
| * can also be helped by using synch signals) and more generally. |
| * This driver tries to utilize the measures described in the app |
| * note. The strength of filtering can be set in the board-* specific |
| * files. |
| */ |
| |
| #define TS_POLL_DELAY 1 /* ms delay before the first sample */ |
| #define TS_POLL_PERIOD 5 /* ms delay between samples */ |
| |
| /* this driver doesn't aim at the peak continuous sample rate */ |
| #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) |
| |
| struct ts_event { |
| /* |
| * For portability, we can't read 12 bit values using SPI (which |
| * would make the controller deliver them as native byte order u16 |
| * with msbs zeroed). Instead, we read them as two 8-bit values, |
| * *** WHICH NEED BYTESWAPPING *** and range adjustment. |
| */ |
| u16 x; |
| u16 y; |
| u16 z1, z2; |
| bool ignore; |
| u8 x_buf[3]; |
| u8 y_buf[3]; |
| }; |
| |
| /* |
| * We allocate this separately to avoid cache line sharing issues when |
| * driver is used with DMA-based SPI controllers (like atmel_spi) on |
| * systems where main memory is not DMA-coherent (most non-x86 boards). |
| */ |
| struct ads7846_packet { |
| u8 read_x, read_y, read_z1, read_z2, pwrdown; |
| u16 dummy; /* for the pwrdown read */ |
| struct ts_event tc; |
| /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ |
| u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; |
| }; |
| |
| struct ads7846 { |
| struct input_dev *input; |
| char phys[32]; |
| char name[32]; |
| |
| struct spi_device *spi; |
| struct regulator *reg; |
| |
| #if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE) |
| struct attribute_group *attr_group; |
| struct device *hwmon; |
| #endif |
| |
| u16 model; |
| u16 vref_mv; |
| u16 vref_delay_usecs; |
| u16 x_plate_ohms; |
| u16 pressure_max; |
| |
| bool swap_xy; |
| bool use_internal; |
| |
| struct ads7846_packet *packet; |
| |
| struct spi_transfer xfer[18]; |
| struct spi_message msg[5]; |
| int msg_count; |
| wait_queue_head_t wait; |
| |
| bool pendown; |
| |
| int read_cnt; |
| int read_rep; |
| int last_read; |
| |
| u16 debounce_max; |
| u16 debounce_tol; |
| u16 debounce_rep; |
| |
| u16 penirq_recheck_delay_usecs; |
| |
| struct mutex lock; |
| bool stopped; /* P: lock */ |
| bool disabled; /* P: lock */ |
| bool suspended; /* P: lock */ |
| |
| int (*filter)(void *data, int data_idx, int *val); |
| void *filter_data; |
| void (*filter_cleanup)(void *data); |
| int (*get_pendown_state)(void); |
| int gpio_pendown; |
| |
| void (*wait_for_sync)(void); |
| }; |
| |
| /* leave chip selected when we're done, for quicker re-select? */ |
| #if 0 |
| #define CS_CHANGE(xfer) ((xfer).cs_change = 1) |
| #else |
| #define CS_CHANGE(xfer) ((xfer).cs_change = 0) |
| #endif |
| |
| /*--------------------------------------------------------------------------*/ |
| |
| /* The ADS7846 has touchscreen and other sensors. |
| * Earlier ads784x chips are somewhat compatible. |
| */ |
| #define ADS_START (1 << 7) |
| #define ADS_A2A1A0_d_y (1 << 4) /* differential */ |
| #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ |
| #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ |
| #define ADS_A2A1A0_d_x (5 << 4) /* differential */ |
| #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ |
| #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ |
| #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ |
| #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ |
| #define ADS_8_BIT (1 << 3) |
| #define ADS_12_BIT (0 << 3) |
| #define ADS_SER (1 << 2) /* non-differential */ |
| #define ADS_DFR (0 << 2) /* differential */ |
| #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ |
| #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ |
| #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ |
| #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ |
| |
| #define MAX_12BIT ((1<<12)-1) |
| |
| /* leave ADC powered up (disables penirq) between differential samples */ |
| #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ |
| | ADS_12_BIT | ADS_DFR | \ |
| (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) |
| |
| #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) |
| #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) |
| #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) |
| |
| #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) |
| #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ |
| |
| /* single-ended samples need to first power up reference voltage; |
| * we leave both ADC and VREF powered |
| */ |
| #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ |
| | ADS_12_BIT | ADS_SER) |
| |
| #define REF_ON (READ_12BIT_DFR(x, 1, 1)) |
| #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) |
| |
| /* Must be called with ts->lock held */ |
| static void ads7846_stop(struct ads7846 *ts) |
| { |
| if (!ts->disabled && !ts->suspended) { |
| /* Signal IRQ thread to stop polling and disable the handler. */ |
| ts->stopped = true; |
| mb(); |
| wake_up(&ts->wait); |
| disable_irq(ts->spi->irq); |
| } |
| } |
| |
| /* Must be called with ts->lock held */ |
| static void ads7846_restart(struct ads7846 *ts) |
| { |
| if (!ts->disabled && !ts->suspended) { |
| /* Tell IRQ thread that it may poll the device. */ |
| ts->stopped = false; |
| mb(); |
| enable_irq(ts->spi->irq); |
| } |
| } |
| |
| /* Must be called with ts->lock held */ |
| static void __ads7846_disable(struct ads7846 *ts) |
| { |
| ads7846_stop(ts); |
| regulator_disable(ts->reg); |
| |
| /* |
| * We know the chip's in low power mode since we always |
| * leave it that way after every request |
| */ |
| } |
| |
| /* Must be called with ts->lock held */ |
| static void __ads7846_enable(struct ads7846 *ts) |
| { |
| regulator_enable(ts->reg); |
| ads7846_restart(ts); |
| } |
| |
| static void ads7846_disable(struct ads7846 *ts) |
| { |
| mutex_lock(&ts->lock); |
| |
| if (!ts->disabled) { |
| |
| if (!ts->suspended) |
| __ads7846_disable(ts); |
| |
| ts->disabled = true; |
| } |
| |
| mutex_unlock(&ts->lock); |
| } |
| |
| static void ads7846_enable(struct ads7846 *ts) |
| { |
| mutex_lock(&ts->lock); |
| |
| if (ts->disabled) { |
| |
| ts->disabled = false; |
| |
| if (!ts->suspended) |
| __ads7846_enable(ts); |
| } |
| |
| mutex_unlock(&ts->lock); |
| } |
| |
| /*--------------------------------------------------------------------------*/ |
| |
| /* |
| * Non-touchscreen sensors only use single-ended conversions. |
| * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; |
| * ads7846 lets that pin be unconnected, to use internal vREF. |
| */ |
| |
| struct ser_req { |
| u8 ref_on; |
| u8 command; |
| u8 ref_off; |
| u16 scratch; |
| 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. |
| */ |
| __be16 sample ____cacheline_aligned; |
| }; |
| |
| struct ads7845_ser_req { |
| u8 command[3]; |
| struct spi_message msg; |
| struct spi_transfer xfer[2]; |
| /* |
| * DMA (thus cache coherency maintenance) requires the |
| * transfer buffers to live in their own cache lines. |
| */ |
| u8 sample[3] ____cacheline_aligned; |
| }; |
| |
| static int ads7846_read12_ser(struct device *dev, unsigned command) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| struct ser_req *req; |
| int status; |
| |
| req = kzalloc(sizeof *req, GFP_KERNEL); |
| if (!req) |
| return -ENOMEM; |
| |
| spi_message_init(&req->msg); |
| |
| /* maybe turn on internal vREF, and let it settle */ |
| if (ts->use_internal) { |
| req->ref_on = REF_ON; |
| req->xfer[0].tx_buf = &req->ref_on; |
| req->xfer[0].len = 1; |
| spi_message_add_tail(&req->xfer[0], &req->msg); |
| |
| req->xfer[1].rx_buf = &req->scratch; |
| req->xfer[1].len = 2; |
| |
| /* for 1uF, settle for 800 usec; no cap, 100 usec. */ |
| req->xfer[1].delay_usecs = ts->vref_delay_usecs; |
| spi_message_add_tail(&req->xfer[1], &req->msg); |
| |
| /* Enable reference voltage */ |
| command |= ADS_PD10_REF_ON; |
| } |
| |
| /* Enable ADC in every case */ |
| command |= ADS_PD10_ADC_ON; |
| |
| /* take sample */ |
| req->command = (u8) command; |
| req->xfer[2].tx_buf = &req->command; |
| req->xfer[2].len = 1; |
| spi_message_add_tail(&req->xfer[2], &req->msg); |
| |
| req->xfer[3].rx_buf = &req->sample; |
| req->xfer[3].len = 2; |
| spi_message_add_tail(&req->xfer[3], &req->msg); |
| |
| /* REVISIT: take a few more samples, and compare ... */ |
| |
| /* converter in low power mode & enable PENIRQ */ |
| req->ref_off = PWRDOWN; |
| req->xfer[4].tx_buf = &req->ref_off; |
| req->xfer[4].len = 1; |
| spi_message_add_tail(&req->xfer[4], &req->msg); |
| |
| req->xfer[5].rx_buf = &req->scratch; |
| req->xfer[5].len = 2; |
| CS_CHANGE(req->xfer[5]); |
| spi_message_add_tail(&req->xfer[5], &req->msg); |
| |
| mutex_lock(&ts->lock); |
| ads7846_stop(ts); |
| status = spi_sync(spi, &req->msg); |
| ads7846_restart(ts); |
| mutex_unlock(&ts->lock); |
| |
| if (status == 0) { |
| /* on-wire is a must-ignore bit, a BE12 value, then padding */ |
| status = be16_to_cpu(req->sample); |
| status = status >> 3; |
| status &= 0x0fff; |
| } |
| |
| kfree(req); |
| return status; |
| } |
| |
| static int ads7845_read12_ser(struct device *dev, unsigned command) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| struct ads7845_ser_req *req; |
| int status; |
| |
| req = kzalloc(sizeof *req, GFP_KERNEL); |
| if (!req) |
| return -ENOMEM; |
| |
| spi_message_init(&req->msg); |
| |
| req->command[0] = (u8) command; |
| req->xfer[0].tx_buf = req->command; |
| req->xfer[0].rx_buf = req->sample; |
| req->xfer[0].len = 3; |
| spi_message_add_tail(&req->xfer[0], &req->msg); |
| |
| mutex_lock(&ts->lock); |
| ads7846_stop(ts); |
| status = spi_sync(spi, &req->msg); |
| ads7846_restart(ts); |
| mutex_unlock(&ts->lock); |
| |
| if (status == 0) { |
| /* BE12 value, then padding */ |
| status = be16_to_cpu(*((u16 *)&req->sample[1])); |
| status = status >> 3; |
| status &= 0x0fff; |
| } |
| |
| kfree(req); |
| return status; |
| } |
| |
| #if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE) |
| |
| #define SHOW(name, var, adjust) static ssize_t \ |
| name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ |
| { \ |
| struct ads7846 *ts = dev_get_drvdata(dev); \ |
| ssize_t v = ads7846_read12_ser(dev, \ |
| READ_12BIT_SER(var)); \ |
| if (v < 0) \ |
| return v; \ |
| return sprintf(buf, "%u\n", adjust(ts, v)); \ |
| } \ |
| static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); |
| |
| |
| /* Sysfs conventions report temperatures in millidegrees Celsius. |
| * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high |
| * accuracy scheme without calibration data. For now we won't try either; |
| * userspace sees raw sensor values, and must scale/calibrate appropriately. |
| */ |
| static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) |
| { |
| return v; |
| } |
| |
| SHOW(temp0, temp0, null_adjust) /* temp1_input */ |
| SHOW(temp1, temp1, null_adjust) /* temp2_input */ |
| |
| |
| /* sysfs conventions report voltages in millivolts. We can convert voltages |
| * if we know vREF. userspace may need to scale vAUX to match the board's |
| * external resistors; we assume that vBATT only uses the internal ones. |
| */ |
| static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) |
| { |
| unsigned retval = v; |
| |
| /* external resistors may scale vAUX into 0..vREF */ |
| retval *= ts->vref_mv; |
| retval = retval >> 12; |
| |
| return retval; |
| } |
| |
| static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) |
| { |
| unsigned retval = vaux_adjust(ts, v); |
| |
| /* ads7846 has a resistor ladder to scale this signal down */ |
| if (ts->model == 7846) |
| retval *= 4; |
| |
| return retval; |
| } |
| |
| SHOW(in0_input, vaux, vaux_adjust) |
| SHOW(in1_input, vbatt, vbatt_adjust) |
| |
| static struct attribute *ads7846_attributes[] = { |
| &dev_attr_temp0.attr, |
| &dev_attr_temp1.attr, |
| &dev_attr_in0_input.attr, |
| &dev_attr_in1_input.attr, |
| NULL, |
| }; |
| |
| static struct attribute_group ads7846_attr_group = { |
| .attrs = ads7846_attributes, |
| }; |
| |
| static struct attribute *ads7843_attributes[] = { |
| &dev_attr_in0_input.attr, |
| &dev_attr_in1_input.attr, |
| NULL, |
| }; |
| |
| static struct attribute_group ads7843_attr_group = { |
| .attrs = ads7843_attributes, |
| }; |
| |
| static struct attribute *ads7845_attributes[] = { |
| &dev_attr_in0_input.attr, |
| NULL, |
| }; |
| |
| static struct attribute_group ads7845_attr_group = { |
| .attrs = ads7845_attributes, |
| }; |
| |
| static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) |
| { |
| struct device *hwmon; |
| int err; |
| |
| /* hwmon sensors need a reference voltage */ |
| switch (ts->model) { |
| case 7846: |
| if (!ts->vref_mv) { |
| dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); |
| ts->vref_mv = 2500; |
| ts->use_internal = true; |
| } |
| break; |
| case 7845: |
| case 7843: |
| if (!ts->vref_mv) { |
| dev_warn(&spi->dev, |
| "external vREF for ADS%d not specified\n", |
| ts->model); |
| return 0; |
| } |
| break; |
| } |
| |
| /* different chips have different sensor groups */ |
| switch (ts->model) { |
| case 7846: |
| ts->attr_group = &ads7846_attr_group; |
| break; |
| case 7845: |
| ts->attr_group = &ads7845_attr_group; |
| break; |
| case 7843: |
| ts->attr_group = &ads7843_attr_group; |
| break; |
| default: |
| dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model); |
| return 0; |
| } |
| |
| err = sysfs_create_group(&spi->dev.kobj, ts->attr_group); |
| if (err) |
| return err; |
| |
| hwmon = hwmon_device_register(&spi->dev); |
| if (IS_ERR(hwmon)) { |
| sysfs_remove_group(&spi->dev.kobj, ts->attr_group); |
| return PTR_ERR(hwmon); |
| } |
| |
| ts->hwmon = hwmon; |
| return 0; |
| } |
| |
| static void ads784x_hwmon_unregister(struct spi_device *spi, |
| struct ads7846 *ts) |
| { |
| if (ts->hwmon) { |
| sysfs_remove_group(&spi->dev.kobj, ts->attr_group); |
| hwmon_device_unregister(ts->hwmon); |
| } |
| } |
| |
| #else |
| static inline int ads784x_hwmon_register(struct spi_device *spi, |
| struct ads7846 *ts) |
| { |
| return 0; |
| } |
| |
| static inline void ads784x_hwmon_unregister(struct spi_device *spi, |
| struct ads7846 *ts) |
| { |
| } |
| #endif |
| |
| static ssize_t ads7846_pen_down_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| |
| return sprintf(buf, "%u\n", ts->pendown); |
| } |
| |
| static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); |
| |
| static ssize_t ads7846_disable_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| |
| return sprintf(buf, "%u\n", ts->disabled); |
| } |
| |
| static ssize_t ads7846_disable_store(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| unsigned int i; |
| int err; |
| |
| err = kstrtouint(buf, 10, &i); |
| if (err) |
| return err; |
| |
| if (i) |
| ads7846_disable(ts); |
| else |
| ads7846_enable(ts); |
| |
| return count; |
| } |
| |
| static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); |
| |
| static struct attribute *ads784x_attributes[] = { |
| &dev_attr_pen_down.attr, |
| &dev_attr_disable.attr, |
| NULL, |
| }; |
| |
| static struct attribute_group ads784x_attr_group = { |
| .attrs = ads784x_attributes, |
| }; |
| |
| /*--------------------------------------------------------------------------*/ |
| |
| static int get_pendown_state(struct ads7846 *ts) |
| { |
| if (ts->get_pendown_state) |
| return ts->get_pendown_state(); |
| |
| return !gpio_get_value(ts->gpio_pendown); |
| } |
| |
| static void null_wait_for_sync(void) |
| { |
| } |
| |
| static int ads7846_debounce_filter(void *ads, int data_idx, int *val) |
| { |
| struct ads7846 *ts = ads; |
| |
| if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { |
| /* Start over collecting consistent readings. */ |
| ts->read_rep = 0; |
| /* |
| * Repeat it, if this was the first read or the read |
| * wasn't consistent enough. |
| */ |
| if (ts->read_cnt < ts->debounce_max) { |
| ts->last_read = *val; |
| ts->read_cnt++; |
| return ADS7846_FILTER_REPEAT; |
| } else { |
| /* |
| * Maximum number of debouncing reached and still |
| * not enough number of consistent readings. Abort |
| * the whole sample, repeat it in the next sampling |
| * period. |
| */ |
| ts->read_cnt = 0; |
| return ADS7846_FILTER_IGNORE; |
| } |
| } else { |
| if (++ts->read_rep > ts->debounce_rep) { |
| /* |
| * Got a good reading for this coordinate, |
| * go for the next one. |
| */ |
| ts->read_cnt = 0; |
| ts->read_rep = 0; |
| return ADS7846_FILTER_OK; |
| } else { |
| /* Read more values that are consistent. */ |
| ts->read_cnt++; |
| return ADS7846_FILTER_REPEAT; |
| } |
| } |
| } |
| |
| static int ads7846_no_filter(void *ads, int data_idx, int *val) |
| { |
| return ADS7846_FILTER_OK; |
| } |
| |
| static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) |
| { |
| struct spi_transfer *t = |
| list_entry(m->transfers.prev, struct spi_transfer, transfer_list); |
| |
| if (ts->model == 7845) { |
| return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3; |
| } else { |
| /* |
| * adjust: on-wire is a must-ignore bit, a BE12 value, then |
| * padding; built from two 8 bit values written msb-first. |
| */ |
| return be16_to_cpup((__be16 *)t->rx_buf) >> 3; |
| } |
| } |
| |
| static void ads7846_update_value(struct spi_message *m, int val) |
| { |
| struct spi_transfer *t = |
| list_entry(m->transfers.prev, struct spi_transfer, transfer_list); |
| |
| *(u16 *)t->rx_buf = val; |
| } |
| |
| static void ads7846_read_state(struct ads7846 *ts) |
| { |
| struct ads7846_packet *packet = ts->packet; |
| struct spi_message *m; |
| int msg_idx = 0; |
| int val; |
| int action; |
| int error; |
| |
| while (msg_idx < ts->msg_count) { |
| |
| ts->wait_for_sync(); |
| |
| m = &ts->msg[msg_idx]; |
| error = spi_sync(ts->spi, m); |
| if (error) { |
| dev_err(&ts->spi->dev, "spi_async --> %d\n", error); |
| packet->tc.ignore = true; |
| return; |
| } |
| |
| /* |
| * Last message is power down request, no need to convert |
| * or filter the value. |
| */ |
| if (msg_idx < ts->msg_count - 1) { |
| |
| val = ads7846_get_value(ts, m); |
| |
| action = ts->filter(ts->filter_data, msg_idx, &val); |
| switch (action) { |
| case ADS7846_FILTER_REPEAT: |
| continue; |
| |
| case ADS7846_FILTER_IGNORE: |
| packet->tc.ignore = true; |
| msg_idx = ts->msg_count - 1; |
| continue; |
| |
| case ADS7846_FILTER_OK: |
| ads7846_update_value(m, val); |
| packet->tc.ignore = false; |
| msg_idx++; |
| break; |
| |
| default: |
| BUG(); |
| } |
| } else { |
| msg_idx++; |
| } |
| } |
| } |
| |
| static void ads7846_report_state(struct ads7846 *ts) |
| { |
| struct ads7846_packet *packet = ts->packet; |
| unsigned int Rt; |
| u16 x, y, z1, z2; |
| |
| /* |
| * ads7846_get_value() does in-place conversion (including byte swap) |
| * from on-the-wire format as part of debouncing to get stable |
| * readings. |
| */ |
| if (ts->model == 7845) { |
| x = *(u16 *)packet->tc.x_buf; |
| y = *(u16 *)packet->tc.y_buf; |
| z1 = 0; |
| z2 = 0; |
| } else { |
| x = packet->tc.x; |
| y = packet->tc.y; |
| z1 = packet->tc.z1; |
| z2 = packet->tc.z2; |
| } |
| |
| /* range filtering */ |
| if (x == MAX_12BIT) |
| x = 0; |
| |
| if (ts->model == 7843) { |
| Rt = ts->pressure_max / 2; |
| } else if (ts->model == 7845) { |
| if (get_pendown_state(ts)) |
| Rt = ts->pressure_max / 2; |
| else |
| Rt = 0; |
| dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); |
| } else if (likely(x && z1)) { |
| /* compute touch pressure resistance using equation #2 */ |
| Rt = z2; |
| Rt -= z1; |
| Rt *= x; |
| Rt *= ts->x_plate_ohms; |
| Rt /= z1; |
| Rt = (Rt + 2047) >> 12; |
| } else { |
| Rt = 0; |
| } |
| |
| /* |
| * Sample found inconsistent by debouncing or pressure is beyond |
| * the maximum. Don't report it to user space, repeat at least |
| * once more the measurement |
| */ |
| if (packet->tc.ignore || Rt > ts->pressure_max) { |
| dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", |
| packet->tc.ignore, Rt); |
| return; |
| } |
| |
| /* |
| * Maybe check the pendown state before reporting. This discards |
| * false readings when the pen is lifted. |
| */ |
| if (ts->penirq_recheck_delay_usecs) { |
| udelay(ts->penirq_recheck_delay_usecs); |
| if (!get_pendown_state(ts)) |
| Rt = 0; |
| } |
| |
| /* |
| * NOTE: We can't rely on the pressure to determine the pen down |
| * state, even this controller has a pressure sensor. The pressure |
| * value can fluctuate for quite a while after lifting the pen and |
| * in some cases may not even settle at the expected value. |
| * |
| * The only safe way to check for the pen up condition is in the |
| * timer by reading the pen signal state (it's a GPIO _and_ IRQ). |
| */ |
| if (Rt) { |
| struct input_dev *input = ts->input; |
| |
| if (ts->swap_xy) |
| swap(x, y); |
| |
| if (!ts->pendown) { |
| input_report_key(input, BTN_TOUCH, 1); |
| ts->pendown = true; |
| dev_vdbg(&ts->spi->dev, "DOWN\n"); |
| } |
| |
| input_report_abs(input, ABS_X, x); |
| input_report_abs(input, ABS_Y, y); |
| input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); |
| |
| input_sync(input); |
| dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); |
| } |
| } |
| |
| static irqreturn_t ads7846_hard_irq(int irq, void *handle) |
| { |
| struct ads7846 *ts = handle; |
| |
| return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; |
| } |
| |
| |
| static irqreturn_t ads7846_irq(int irq, void *handle) |
| { |
| struct ads7846 *ts = handle; |
| |
| /* Start with a small delay before checking pendown state */ |
| msleep(TS_POLL_DELAY); |
| |
| while (!ts->stopped && get_pendown_state(ts)) { |
| |
| /* pen is down, continue with the measurement */ |
| ads7846_read_state(ts); |
| |
| if (!ts->stopped) |
| ads7846_report_state(ts); |
| |
| wait_event_timeout(ts->wait, ts->stopped, |
| msecs_to_jiffies(TS_POLL_PERIOD)); |
| } |
| |
| if (ts->pendown) { |
| struct input_dev *input = ts->input; |
| |
| input_report_key(input, BTN_TOUCH, 0); |
| input_report_abs(input, ABS_PRESSURE, 0); |
| input_sync(input); |
| |
| ts->pendown = false; |
| dev_vdbg(&ts->spi->dev, "UP\n"); |
| } |
| |
| return IRQ_HANDLED; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int ads7846_suspend(struct device *dev) |
| { |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| |
| mutex_lock(&ts->lock); |
| |
| if (!ts->suspended) { |
| |
| if (!ts->disabled) |
| __ads7846_disable(ts); |
| |
| if (device_may_wakeup(&ts->spi->dev)) |
| enable_irq_wake(ts->spi->irq); |
| |
| ts->suspended = true; |
| } |
| |
| mutex_unlock(&ts->lock); |
| |
| return 0; |
| } |
| |
| static int ads7846_resume(struct device *dev) |
| { |
| struct ads7846 *ts = dev_get_drvdata(dev); |
| |
| mutex_lock(&ts->lock); |
| |
| if (ts->suspended) { |
| |
| ts->suspended = false; |
| |
| if (device_may_wakeup(&ts->spi->dev)) |
| disable_irq_wake(ts->spi->irq); |
| |
| if (!ts->disabled) |
| __ads7846_enable(ts); |
| } |
| |
| mutex_unlock(&ts->lock); |
| |
| return 0; |
| } |
| #endif |
| |
| static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); |
| |
| static int __devinit ads7846_setup_pendown(struct spi_device *spi, struct ads7846 *ts) |
| { |
| struct ads7846_platform_data *pdata = spi->dev.platform_data; |
| int err; |
| |
| /* |
| * REVISIT when the irq can be triggered active-low, or if for some |
| * reason the touchscreen isn't hooked up, we don't need to access |
| * the pendown state. |
| */ |
| |
| if (pdata->get_pendown_state) { |
| ts->get_pendown_state = pdata->get_pendown_state; |
| } else if (gpio_is_valid(pdata->gpio_pendown)) { |
| |
| err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, |
| "ads7846_pendown"); |
| if (err) { |
| dev_err(&spi->dev, |
| "failed to request/setup pendown GPIO%d: %d\n", |
| pdata->gpio_pendown, err); |
| return err; |
| } |
| |
| ts->gpio_pendown = pdata->gpio_pendown; |
| |
| } else { |
| dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Set up the transfers to read touchscreen state; this assumes we |
| * use formula #2 for pressure, not #3. |
| */ |
| static void __devinit ads7846_setup_spi_msg(struct ads7846 *ts, |
| const struct ads7846_platform_data *pdata) |
| { |
| struct spi_message *m = &ts->msg[0]; |
| struct spi_transfer *x = ts->xfer; |
| struct ads7846_packet *packet = ts->packet; |
| int vref = pdata->keep_vref_on; |
| |
| if (ts->model == 7873) { |
| /* |
| * The AD7873 is almost identical to the ADS7846 |
| * keep VREF off during differential/ratiometric |
| * conversion modes. |
| */ |
| ts->model = 7846; |
| vref = 0; |
| } |
| |
| ts->msg_count = 1; |
| spi_message_init(m); |
| m->context = ts; |
| |
| if (ts->model == 7845) { |
| packet->read_y_cmd[0] = READ_Y(vref); |
| packet->read_y_cmd[1] = 0; |
| packet->read_y_cmd[2] = 0; |
| x->tx_buf = &packet->read_y_cmd[0]; |
| x->rx_buf = &packet->tc.y_buf[0]; |
| x->len = 3; |
| spi_message_add_tail(x, m); |
| } else { |
| /* y- still on; turn on only y+ (and ADC) */ |
| packet->read_y = READ_Y(vref); |
| x->tx_buf = &packet->read_y; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.y; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| } |
| |
| /* |
| * The first sample after switching drivers can be low quality; |
| * optionally discard it, using a second one after the signals |
| * have had enough time to stabilize. |
| */ |
| if (pdata->settle_delay_usecs) { |
| x->delay_usecs = pdata->settle_delay_usecs; |
| |
| x++; |
| x->tx_buf = &packet->read_y; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.y; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| } |
| |
| ts->msg_count++; |
| m++; |
| spi_message_init(m); |
| m->context = ts; |
| |
| if (ts->model == 7845) { |
| x++; |
| packet->read_x_cmd[0] = READ_X(vref); |
| packet->read_x_cmd[1] = 0; |
| packet->read_x_cmd[2] = 0; |
| x->tx_buf = &packet->read_x_cmd[0]; |
| x->rx_buf = &packet->tc.x_buf[0]; |
| x->len = 3; |
| spi_message_add_tail(x, m); |
| } else { |
| /* turn y- off, x+ on, then leave in lowpower */ |
| x++; |
| packet->read_x = READ_X(vref); |
| x->tx_buf = &packet->read_x; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.x; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| } |
| |
| /* ... maybe discard first sample ... */ |
| if (pdata->settle_delay_usecs) { |
| x->delay_usecs = pdata->settle_delay_usecs; |
| |
| x++; |
| x->tx_buf = &packet->read_x; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.x; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| } |
| |
| /* turn y+ off, x- on; we'll use formula #2 */ |
| if (ts->model == 7846) { |
| ts->msg_count++; |
| m++; |
| spi_message_init(m); |
| m->context = ts; |
| |
| x++; |
| packet->read_z1 = READ_Z1(vref); |
| x->tx_buf = &packet->read_z1; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.z1; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| |
| /* ... maybe discard first sample ... */ |
| if (pdata->settle_delay_usecs) { |
| x->delay_usecs = pdata->settle_delay_usecs; |
| |
| x++; |
| x->tx_buf = &packet->read_z1; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.z1; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| } |
| |
| ts->msg_count++; |
| m++; |
| spi_message_init(m); |
| m->context = ts; |
| |
| x++; |
| packet->read_z2 = READ_Z2(vref); |
| x->tx_buf = &packet->read_z2; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.z2; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| |
| /* ... maybe discard first sample ... */ |
| if (pdata->settle_delay_usecs) { |
| x->delay_usecs = pdata->settle_delay_usecs; |
| |
| x++; |
| x->tx_buf = &packet->read_z2; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->tc.z2; |
| x->len = 2; |
| spi_message_add_tail(x, m); |
| } |
| } |
| |
| /* power down */ |
| ts->msg_count++; |
| m++; |
| spi_message_init(m); |
| m->context = ts; |
| |
| if (ts->model == 7845) { |
| x++; |
| packet->pwrdown_cmd[0] = PWRDOWN; |
| packet->pwrdown_cmd[1] = 0; |
| packet->pwrdown_cmd[2] = 0; |
| x->tx_buf = &packet->pwrdown_cmd[0]; |
| x->len = 3; |
| } else { |
| x++; |
| packet->pwrdown = PWRDOWN; |
| x->tx_buf = &packet->pwrdown; |
| x->len = 1; |
| spi_message_add_tail(x, m); |
| |
| x++; |
| x->rx_buf = &packet->dummy; |
| x->len = 2; |
| } |
| |
| CS_CHANGE(*x); |
| spi_message_add_tail(x, m); |
| } |
| |
| static int __devinit ads7846_probe(struct spi_device *spi) |
| { |
| struct ads7846 *ts; |
| struct ads7846_packet *packet; |
| struct input_dev *input_dev; |
| struct ads7846_platform_data *pdata = spi->dev.platform_data; |
| unsigned long irq_flags; |
| int err; |
| |
| if (!spi->irq) { |
| dev_dbg(&spi->dev, "no IRQ?\n"); |
| return -ENODEV; |
| } |
| |
| if (!pdata) { |
| dev_dbg(&spi->dev, "no platform data?\n"); |
| return -ENODEV; |
| } |
| |
| /* don't exceed max specified sample rate */ |
| if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { |
| dev_dbg(&spi->dev, "f(sample) %d KHz?\n", |
| (spi->max_speed_hz/SAMPLE_BITS)/1000); |
| return -EINVAL; |
| } |
| |
| /* We'd set TX word size 8 bits and RX word size to 13 bits ... except |
| * that even if the hardware can do that, the SPI controller driver |
| * may not. So we stick to very-portable 8 bit words, both RX and TX. |
| */ |
| spi->bits_per_word = 8; |
| spi->mode = SPI_MODE_0; |
| err = spi_setup(spi); |
| if (err < 0) |
| return err; |
| |
| ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); |
| packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); |
| input_dev = input_allocate_device(); |
| if (!ts || !packet || !input_dev) { |
| err = -ENOMEM; |
| goto err_free_mem; |
| } |
| |
| dev_set_drvdata(&spi->dev, ts); |
| |
| ts->packet = packet; |
| ts->spi = spi; |
| ts->input = input_dev; |
| ts->vref_mv = pdata->vref_mv; |
| ts->swap_xy = pdata->swap_xy; |
| |
| mutex_init(&ts->lock); |
| init_waitqueue_head(&ts->wait); |
| |
| ts->model = pdata->model ? : 7846; |
| ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; |
| ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; |
| ts->pressure_max = pdata->pressure_max ? : ~0; |
| |
| if (pdata->filter != NULL) { |
| if (pdata->filter_init != NULL) { |
| err = pdata->filter_init(pdata, &ts->filter_data); |
| if (err < 0) |
| goto err_free_mem; |
| } |
| ts->filter = pdata->filter; |
| ts->filter_cleanup = pdata->filter_cleanup; |
| } else if (pdata->debounce_max) { |
| ts->debounce_max = pdata->debounce_max; |
| if (ts->debounce_max < 2) |
| ts->debounce_max = 2; |
| ts->debounce_tol = pdata->debounce_tol; |
| ts->debounce_rep = pdata->debounce_rep; |
| ts->filter = ads7846_debounce_filter; |
| ts->filter_data = ts; |
| } else { |
| ts->filter = ads7846_no_filter; |
| } |
| |
| err = ads7846_setup_pendown(spi, ts); |
| if (err) |
| goto err_cleanup_filter; |
| |
| if (pdata->penirq_recheck_delay_usecs) |
| ts->penirq_recheck_delay_usecs = |
| pdata->penirq_recheck_delay_usecs; |
| |
| ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; |
| |
| snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); |
| snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); |
| |
| input_dev->name = ts->name; |
| input_dev->phys = ts->phys; |
| input_dev->dev.parent = &spi->dev; |
| |
| input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
| input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
| input_set_abs_params(input_dev, ABS_X, |
| pdata->x_min ? : 0, |
| pdata->x_max ? : MAX_12BIT, |
| 0, 0); |
| input_set_abs_params(input_dev, ABS_Y, |
| pdata->y_min ? : 0, |
| pdata->y_max ? : MAX_12BIT, |
| 0, 0); |
| input_set_abs_params(input_dev, ABS_PRESSURE, |
| pdata->pressure_min, pdata->pressure_max, 0, 0); |
| |
| ads7846_setup_spi_msg(ts, pdata); |
| |
| ts->reg = regulator_get(&spi->dev, "vcc"); |
| if (IS_ERR(ts->reg)) { |
| err = PTR_ERR(ts->reg); |
| dev_err(&spi->dev, "unable to get regulator: %d\n", err); |
| goto err_free_gpio; |
| } |
| |
| err = regulator_enable(ts->reg); |
| if (err) { |
| dev_err(&spi->dev, "unable to enable regulator: %d\n", err); |
| goto err_put_regulator; |
| } |
| |
| irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; |
| irq_flags |= IRQF_ONESHOT; |
| |
| err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, |
| irq_flags, spi->dev.driver->name, ts); |
| if (err && !pdata->irq_flags) { |
| dev_info(&spi->dev, |
| "trying pin change workaround on irq %d\n", spi->irq); |
| irq_flags |= IRQF_TRIGGER_RISING; |
| err = request_threaded_irq(spi->irq, |
| ads7846_hard_irq, ads7846_irq, |
| irq_flags, spi->dev.driver->name, ts); |
| } |
| |
| if (err) { |
| dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); |
| goto err_disable_regulator; |
| } |
| |
| err = ads784x_hwmon_register(spi, ts); |
| if (err) |
| goto err_free_irq; |
| |
| dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); |
| |
| /* |
| * Take a first sample, leaving nPENIRQ active and vREF off; avoid |
| * the touchscreen, in case it's not connected. |
| */ |
| if (ts->model == 7845) |
| ads7845_read12_ser(&spi->dev, PWRDOWN); |
| else |
| (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); |
| |
| err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); |
| if (err) |
| goto err_remove_hwmon; |
| |
| err = input_register_device(input_dev); |
| if (err) |
| goto err_remove_attr_group; |
| |
| device_init_wakeup(&spi->dev, pdata->wakeup); |
| |
| return 0; |
| |
| err_remove_attr_group: |
| sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); |
| err_remove_hwmon: |
| ads784x_hwmon_unregister(spi, ts); |
| err_free_irq: |
| free_irq(spi->irq, ts); |
| err_disable_regulator: |
| regulator_disable(ts->reg); |
| err_put_regulator: |
| regulator_put(ts->reg); |
| err_free_gpio: |
| if (!ts->get_pendown_state) |
| gpio_free(ts->gpio_pendown); |
| err_cleanup_filter: |
| if (ts->filter_cleanup) |
| ts->filter_cleanup(ts->filter_data); |
| err_free_mem: |
| input_free_device(input_dev); |
| kfree(packet); |
| kfree(ts); |
| return err; |
| } |
| |
| static int __devexit ads7846_remove(struct spi_device *spi) |
| { |
| struct ads7846 *ts = dev_get_drvdata(&spi->dev); |
| |
| device_init_wakeup(&spi->dev, false); |
| |
| sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); |
| |
| ads7846_disable(ts); |
| free_irq(ts->spi->irq, ts); |
| |
| input_unregister_device(ts->input); |
| |
| ads784x_hwmon_unregister(spi, ts); |
| |
| regulator_disable(ts->reg); |
| regulator_put(ts->reg); |
| |
| if (!ts->get_pendown_state) { |
| /* |
| * If we are not using specialized pendown method we must |
| * have been relying on gpio we set up ourselves. |
| */ |
| gpio_free(ts->gpio_pendown); |
| } |
| |
| if (ts->filter_cleanup) |
| ts->filter_cleanup(ts->filter_data); |
| |
| kfree(ts->packet); |
| kfree(ts); |
| |
| dev_dbg(&spi->dev, "unregistered touchscreen\n"); |
| |
| return 0; |
| } |
| |
| static struct spi_driver ads7846_driver = { |
| .driver = { |
| .name = "ads7846", |
| .owner = THIS_MODULE, |
| .pm = &ads7846_pm, |
| }, |
| .probe = ads7846_probe, |
| .remove = __devexit_p(ads7846_remove), |
| }; |
| |
| static int __init ads7846_init(void) |
| { |
| return spi_register_driver(&ads7846_driver); |
| } |
| module_init(ads7846_init); |
| |
| static void __exit ads7846_exit(void) |
| { |
| spi_unregister_driver(&ads7846_driver); |
| } |
| module_exit(ads7846_exit); |
| |
| MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("spi:ads7846"); |