/* * Copyright (C) 2008-2009 Michael Hennerich, Analog Devices Inc. * * Description: AD7879/AD7889 based touchscreen, and GPIO driver * (I2C/SPI Interface) * * Bugs: Enter bugs at http://blackfin.uclinux.org/ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see the file COPYING, or write * to the Free Software Foundation, Inc., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * History: * Copyright (c) 2005 David Brownell * Copyright (c) 2006 Nokia Corporation * Various changes: Imre Deak * * 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 * - ad7877.c * Copyright (C) 2006-2008 Analog Devices Inc. */ #include #include #include #include #include #include #include #include #include #include #include #define AD7879_REG_ZEROS 0 #define AD7879_REG_CTRL1 1 #define AD7879_REG_CTRL2 2 #define AD7879_REG_CTRL3 3 #define AD7879_REG_AUX1HIGH 4 #define AD7879_REG_AUX1LOW 5 #define AD7879_REG_TEMP1HIGH 6 #define AD7879_REG_TEMP1LOW 7 #define AD7879_REG_XPLUS 8 #define AD7879_REG_YPLUS 9 #define AD7879_REG_Z1 10 #define AD7879_REG_Z2 11 #define AD7879_REG_AUXVBAT 12 #define AD7879_REG_TEMP 13 #define AD7879_REG_REVID 14 /* Control REG 1 */ #define AD7879_TMR(x) ((x & 0xFF) << 0) #define AD7879_ACQ(x) ((x & 0x3) << 8) #define AD7879_MODE_NOC (0 << 10) /* Do not convert */ #define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */ #define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */ #define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */ #define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */ /* Control REG 2 */ #define AD7879_FCD(x) ((x & 0x3) << 0) #define AD7879_RESET (1 << 4) #define AD7879_MFS(x) ((x & 0x3) << 5) #define AD7879_AVG(x) ((x & 0x3) << 7) #define AD7879_SER (1 << 9) /* non-differential */ #define AD7879_DFR (0 << 9) /* differential */ #define AD7879_GPIOPOL (1 << 10) #define AD7879_GPIODIR (1 << 11) #define AD7879_GPIO_DATA (1 << 12) #define AD7879_GPIO_EN (1 << 13) #define AD7879_PM(x) ((x & 0x3) << 14) #define AD7879_PM_SHUTDOWN (0) #define AD7879_PM_DYN (1) #define AD7879_PM_FULLON (2) /* Control REG 3 */ #define AD7879_TEMPMASK_BIT (1<<15) #define AD7879_AUXVBATMASK_BIT (1<<14) #define AD7879_INTMODE_BIT (1<<13) #define AD7879_GPIOALERTMASK_BIT (1<<12) #define AD7879_AUXLOW_BIT (1<<11) #define AD7879_AUXHIGH_BIT (1<<10) #define AD7879_TEMPLOW_BIT (1<<9) #define AD7879_TEMPHIGH_BIT (1<<8) #define AD7879_YPLUS_BIT (1<<7) #define AD7879_XPLUS_BIT (1<<6) #define AD7879_Z1_BIT (1<<5) #define AD7879_Z2_BIT (1<<4) #define AD7879_AUX_BIT (1<<3) #define AD7879_VBAT_BIT (1<<2) #define AD7879_TEMP_BIT (1<<1) enum { AD7879_SEQ_XPOS = 0, AD7879_SEQ_YPOS = 1, AD7879_SEQ_Z1 = 2, AD7879_SEQ_Z2 = 3, AD7879_NR_SENSE = 4, }; #define MAX_12BIT ((1<<12)-1) #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50) #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE) #define AD7879_DEVID 0x7A typedef struct spi_device bus_device; #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE) #define AD7879_DEVID 0x79 typedef struct i2c_client bus_device; #endif struct ad7879 { bus_device *bus; struct input_dev *input; struct work_struct work; struct timer_list timer; struct mutex mutex; unsigned disabled:1; /* P: mutex */ #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE) struct spi_message msg; struct spi_transfer xfer[AD7879_NR_SENSE + 1]; u16 cmd; #endif u16 conversion_data[AD7879_NR_SENSE]; char phys[32]; u8 first_conversion_delay; u8 acquisition_time; u8 averaging; u8 pen_down_acc_interval; u8 median; u16 x_plate_ohms; u16 pressure_max; u16 gpio_init; u16 cmd_crtl1; u16 cmd_crtl2; u16 cmd_crtl3; unsigned gpio:1; }; static int ad7879_read(bus_device *, u8); static int ad7879_write(bus_device *, u8, u16); static void ad7879_collect(struct ad7879 *); static void ad7879_report(struct ad7879 *ts) { struct input_dev *input_dev = ts->input; unsigned Rt; u16 x, y, z1, z2; x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT; y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT; z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT; z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT; /* * The samples processed here are already preprocessed by the AD7879. * The preprocessing function consists of a median and an averaging filter. * The combination of these two techniques provides a robust solution, * discarding the spurious noise in the signal and keeping only the data of interest. * The size of both filters is programmable. (dev.platform_data, see linux/spi/ad7879.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; 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); } } static void ad7879_work(struct work_struct *work) { struct ad7879 *ts = container_of(work, struct ad7879, work); /* use keventd context to read the result registers */ ad7879_collect(ts); ad7879_report(ts); mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); } static void ad7879_ts_event_release(struct ad7879 *ts) { struct input_dev *input_dev = ts->input; input_report_abs(input_dev, ABS_PRESSURE, 0); input_sync(input_dev); } static void ad7879_timer(unsigned long handle) { struct ad7879 *ts = (void *)handle; ad7879_ts_event_release(ts); } static irqreturn_t ad7879_irq(int irq, void *handle) { struct ad7879 *ts = handle; /* The repeated conversion sequencer controlled by TMR kicked off too fast. * We ignore the last and process the sample sequence currently in the queue. * It can't be older than 9.4ms */ if (!work_pending(&ts->work)) schedule_work(&ts->work); return IRQ_HANDLED; } static void ad7879_setup(struct ad7879 *ts) { ts->cmd_crtl3 = AD7879_YPLUS_BIT | AD7879_XPLUS_BIT | AD7879_Z2_BIT | AD7879_Z1_BIT | AD7879_TEMPMASK_BIT | AD7879_AUXVBATMASK_BIT | AD7879_GPIOALERTMASK_BIT; ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | AD7879_AVG(ts->averaging) | AD7879_MFS(ts->median) | AD7879_FCD(ts->first_conversion_delay) | ts->gpio_init; ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | AD7879_ACQ(ts->acquisition_time) | AD7879_TMR(ts->pen_down_acc_interval); ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2); ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3); ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1); } static void ad7879_disable(struct ad7879 *ts) { mutex_lock(&ts->mutex); if (!ts->disabled) { ts->disabled = 1; disable_irq(ts->bus->irq); cancel_work_sync(&ts->work); if (del_timer_sync(&ts->timer)) ad7879_ts_event_release(ts); ad7879_write(ts->bus, AD7879_REG_CTRL2, AD7879_PM(AD7879_PM_SHUTDOWN)); } mutex_unlock(&ts->mutex); } static void ad7879_enable(struct ad7879 *ts) { mutex_lock(&ts->mutex); if (ts->disabled) { ad7879_setup(ts); ts->disabled = 0; enable_irq(ts->bus->irq); } mutex_unlock(&ts->mutex); } static ssize_t ad7879_disable_show(struct device *dev, struct device_attribute *attr, char *buf) { struct ad7879 *ts = dev_get_drvdata(dev); return sprintf(buf, "%u\n", ts->disabled); } static ssize_t ad7879_disable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ad7879 *ts = dev_get_drvdata(dev); unsigned long val; int error; error = strict_strtoul(buf, 10, &val); if (error) return error; if (val) ad7879_disable(ts); else ad7879_enable(ts); return count; } static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); static ssize_t ad7879_gpio_show(struct device *dev, struct device_attribute *attr, char *buf) { struct ad7879 *ts = dev_get_drvdata(dev); return sprintf(buf, "%u\n", ts->gpio); } static ssize_t ad7879_gpio_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ad7879 *ts = dev_get_drvdata(dev); unsigned long val; int error; error = strict_strtoul(buf, 10, &val); if (error) return error; mutex_lock(&ts->mutex); ts->gpio = !!val; error = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->gpio ? ts->cmd_crtl2 & ~AD7879_GPIO_DATA : ts->cmd_crtl2 | AD7879_GPIO_DATA); mutex_unlock(&ts->mutex); return error ? : count; } static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store); static struct attribute *ad7879_attributes[] = { &dev_attr_disable.attr, &dev_attr_gpio.attr, NULL }; static const struct attribute_group ad7879_attr_group = { .attrs = ad7879_attributes, }; static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts) { struct input_dev *input_dev; struct ad7879_platform_data *pdata = bus->dev.platform_data; int err; u16 revid; if (!bus->irq) { dev_err(&bus->dev, "no IRQ?\n"); return -ENODEV; } if (!pdata) { dev_err(&bus->dev, "no platform data?\n"); return -ENODEV; } input_dev = input_allocate_device(); if (!input_dev) return -ENOMEM; ts->input = input_dev; setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); INIT_WORK(&ts->work, ad7879_work); mutex_init(&ts->mutex); ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; ts->pressure_max = pdata->pressure_max ? : ~0; ts->first_conversion_delay = pdata->first_conversion_delay; ts->acquisition_time = pdata->acquisition_time; ts->averaging = pdata->averaging; ts->pen_down_acc_interval = pdata->pen_down_acc_interval; ts->median = pdata->median; if (pdata->gpio_output) ts->gpio_init = AD7879_GPIO_EN | (pdata->gpio_default ? 0 : AD7879_GPIO_DATA); else ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR; snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev)); input_dev->name = "AD7879 Touchscreen"; input_dev->phys = ts->phys; input_dev->dev.parent = &bus->dev; __set_bit(EV_ABS, input_dev->evbit); __set_bit(ABS_X, input_dev->absbit); __set_bit(ABS_Y, input_dev->absbit); __set_bit(ABS_PRESSURE, input_dev->absbit); 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); err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET); if (err < 0) { dev_err(&bus->dev, "Failed to write %s\n", input_dev->name); goto err_free_mem; } revid = ad7879_read(bus, AD7879_REG_REVID); if ((revid & 0xFF) != AD7879_DEVID) { dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name); err = -ENODEV; goto err_free_mem; } ad7879_setup(ts); err = request_irq(bus->irq, ad7879_irq, IRQF_TRIGGER_FALLING, bus->dev.driver->name, ts); if (err) { dev_err(&bus->dev, "irq %d busy?\n", bus->irq); goto err_free_mem; } err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group); if (err) goto err_free_irq; err = input_register_device(input_dev); if (err) goto err_remove_attr; dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n", revid >> 8, bus->irq); return 0; err_remove_attr: sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group); err_free_irq: free_irq(bus->irq, ts); err_free_mem: input_free_device(input_dev); return err; } static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts) { ad7879_disable(ts); sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group); free_irq(ts->bus->irq, ts); input_unregister_device(ts->input); dev_dbg(&bus->dev, "unregistered touchscreen\n"); return 0; } #ifdef CONFIG_PM static int ad7879_suspend(bus_device *bus, pm_message_t message) { struct ad7879 *ts = dev_get_drvdata(&bus->dev); ad7879_disable(ts); return 0; } static int ad7879_resume(bus_device *bus) { struct ad7879 *ts = dev_get_drvdata(&bus->dev); ad7879_enable(ts); return 0; } #else #define ad7879_suspend NULL #define ad7879_resume NULL #endif #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE) #define MAX_SPI_FREQ_HZ 5000000 #define AD7879_CMD_MAGIC 0xE000 #define AD7879_CMD_READ (1 << 10) #define AD7879_WRITECMD(reg) (AD7879_CMD_MAGIC | (reg & 0xF)) #define AD7879_READCMD(reg) (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF)) struct ser_req { u16 command; u16 data; struct spi_message msg; struct spi_transfer xfer[2]; }; /* * ad7879_read/write are only used for initial setup and for sysfs controls. * The main traffic is done in ad7879_collect(). */ static int ad7879_read(struct spi_device *spi, u8 reg) { struct ser_req *req; int status, ret; req = kzalloc(sizeof *req, GFP_KERNEL); if (!req) return -ENOMEM; spi_message_init(&req->msg); req->command = (u16) AD7879_READCMD(reg); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; req->xfer[1].rx_buf = &req->data; 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->data; kfree(req); return ret; } static int ad7879_write(struct spi_device *spi, u8 reg, u16 val) { struct ser_req *req; int status; req = kzalloc(sizeof *req, GFP_KERNEL); if (!req) return -ENOMEM; spi_message_init(&req->msg); req->command = (u16) AD7879_WRITECMD(reg); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; req->data = val; req->xfer[1].tx_buf = &req->data; 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); kfree(req); return status; } static void ad7879_collect(struct ad7879 *ts) { int status = spi_sync(ts->bus, &ts->msg); if (status) dev_err(&ts->bus->dev, "spi_sync --> %d\n", status); } static void ad7879_setup_ts_def_msg(struct ad7879 *ts) { struct spi_message *m; int i; ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS); m = &ts->msg; spi_message_init(m); ts->xfer[0].tx_buf = &ts->cmd; ts->xfer[0].len = 2; spi_message_add_tail(&ts->xfer[0], m); for (i = 0; i < AD7879_NR_SENSE; i++) { ts->xfer[i + 1].rx_buf = &ts->conversion_data[i]; ts->xfer[i + 1].len = 2; spi_message_add_tail(&ts->xfer[i + 1], m); } } static int __devinit ad7879_probe(struct spi_device *spi) { struct ad7879 *ts; int error; /* don't exceed max specified SPI CLK frequency */ if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz); return -EINVAL; } ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL); if (!ts) return -ENOMEM; dev_set_drvdata(&spi->dev, ts); ts->bus = spi; ad7879_setup_ts_def_msg(ts); error = ad7879_construct(spi, ts); if (error) { dev_set_drvdata(&spi->dev, NULL); kfree(ts); } return error; } static int __devexit ad7879_remove(struct spi_device *spi) { struct ad7879 *ts = dev_get_drvdata(&spi->dev); ad7879_destroy(spi, ts); dev_set_drvdata(&spi->dev, NULL); kfree(ts); return 0; } static struct spi_driver ad7879_driver = { .driver = { .name = "ad7879", .bus = &spi_bus_type, .owner = THIS_MODULE, }, .probe = ad7879_probe, .remove = __devexit_p(ad7879_remove), .suspend = ad7879_suspend, .resume = ad7879_resume, }; static int __init ad7879_init(void) { return spi_register_driver(&ad7879_driver); } module_init(ad7879_init); static void __exit ad7879_exit(void) { spi_unregister_driver(&ad7879_driver); } module_exit(ad7879_exit); #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE) /* All registers are word-sized. * AD7879 uses a high-byte first convention. */ static int ad7879_read(struct i2c_client *client, u8 reg) { return swab16(i2c_smbus_read_word_data(client, reg)); } static int ad7879_write(struct i2c_client *client, u8 reg, u16 val) { return i2c_smbus_write_word_data(client, reg, swab16(val)); } static void ad7879_collect(struct ad7879 *ts) { int i; for (i = 0; i < AD7879_NR_SENSE; i++) ts->conversion_data[i] = ad7879_read(ts->bus, AD7879_REG_XPLUS + i); } static int __devinit ad7879_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct ad7879 *ts; int error; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) { dev_err(&client->dev, "SMBUS Word Data not Supported\n"); return -EIO; } ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL); if (!ts) return -ENOMEM; i2c_set_clientdata(client, ts); ts->bus = client; error = ad7879_construct(client, ts); if (error) { i2c_set_clientdata(client, NULL); kfree(ts); } return error; } static int __devexit ad7879_remove(struct i2c_client *client) { struct ad7879 *ts = dev_get_drvdata(&client->dev); ad7879_destroy(client, ts); i2c_set_clientdata(client, NULL); kfree(ts); return 0; } static const struct i2c_device_id ad7879_id[] = { { "ad7879", 0 }, { "ad7889", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, ad7879_id); static struct i2c_driver ad7879_driver = { .driver = { .name = "ad7879", .owner = THIS_MODULE, }, .probe = ad7879_probe, .remove = __devexit_p(ad7879_remove), .suspend = ad7879_suspend, .resume = ad7879_resume, .id_table = ad7879_id, }; static int __init ad7879_init(void) { return i2c_add_driver(&ad7879_driver); } module_init(ad7879_init); static void __exit ad7879_exit(void) { i2c_del_driver(&ad7879_driver); } module_exit(ad7879_exit); #endif MODULE_AUTHOR("Michael Hennerich "); MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:ad7879");