| /* |
| * drivers/input/touchscreen/tsc2004.c |
| * |
| * Copyright (C) 2009 Texas Instruments Inc |
| * Author: Vaibhav Hiremath <hvaibhav@ti.com> |
| * |
| * Using code from: |
| * - tsc2007.c |
| * |
| * This package 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. |
| * |
| * 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, write to the Free Software |
| * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/input.h> |
| #include <linux/interrupt.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c/tsc2004.h> |
| |
| |
| #define TS_POLL_DELAY 1 /* ms delay between samples */ |
| #define TS_POLL_PERIOD 1 /* ms delay between samples */ |
| |
| /* Control byte 0 */ |
| #define TSC2004_CMD0(addr, pnd, rw) ((addr<<3)|(pnd<<1)|rw) |
| /* Control byte 1 */ |
| #define TSC2004_CMD1(cmd, mode, rst) ((1<<7)|(cmd<<4)|(mode<<2)|(rst<<1)) |
| |
| /* Command Bits */ |
| #define READ_REG 1 |
| #define WRITE_REG 0 |
| #define SWRST_TRUE 1 |
| #define SWRST_FALSE 0 |
| #define PND0_TRUE 1 |
| #define PND0_FALSE 0 |
| |
| /* Converter function mapping */ |
| enum convertor_function { |
| MEAS_X_Y_Z1_Z2, /* Measure X,Y,z1 and Z2: 0x0 */ |
| MEAS_X_Y, /* Measure X and Y only: 0x1 */ |
| MEAS_X, /* Measure X only: 0x2 */ |
| MEAS_Y, /* Measure Y only: 0x3 */ |
| MEAS_Z1_Z2, /* Measure Z1 and Z2 only: 0x4 */ |
| MEAS_AUX, /* Measure Auxillary input: 0x5 */ |
| MEAS_TEMP1, /* Measure Temparature1: 0x6 */ |
| MEAS_TEMP2, /* Measure Temparature2: 0x7 */ |
| MEAS_AUX_CONT, /* Continuously measure Auxillary input: 0x8 */ |
| X_DRV_TEST, /* X-Axis drivers tested 0x9 */ |
| Y_DRV_TEST, /* Y-Axis drivers tested 0xA */ |
| /*Command Reserved*/ |
| SHORT_CKT_TST = 0xC, /* Short circuit test: 0xC */ |
| XP_XN_DRV_STAT, /* X+,Y- drivers status: 0xD */ |
| YP_YN_DRV_STAT, /* X+,Y- drivers status: 0xE */ |
| YP_XN_DRV_STAT /* Y+,X- drivers status: 0xF */ |
| }; |
| |
| /* Register address mapping */ |
| enum register_address { |
| X_REG, /* X register: 0x0 */ |
| Y_REG, /* Y register: 0x1 */ |
| Z1_REG, /* Z1 register: 0x2 */ |
| Z2_REG, /* Z2 register: 0x3 */ |
| AUX_REG, /* AUX register: 0x4 */ |
| TEMP1_REG, /* Temp1 register: 0x5 */ |
| TEMP2_REG, /* Temp2 register: 0x6 */ |
| STAT_REG, /* Status Register: 0x7 */ |
| AUX_HGH_TH_REG, /* AUX high threshold register: 0x8 */ |
| AUX_LOW_TH_REG, /* AUX low threshold register: 0x9 */ |
| TMP_HGH_TH_REG, /* Temp high threshold register:0xA */ |
| TMP_LOW_TH_REG, /* Temp low threshold register: 0xB */ |
| CFR0_REG, /* Configuration register 0: 0xC */ |
| CFR1_REG, /* Configuration register 1: 0xD */ |
| CFR2_REG, /* Configuration register 2: 0xE */ |
| CONV_FN_SEL_STAT /* Convertor function select register: 0xF */ |
| }; |
| |
| /* Supported Resolution modes */ |
| enum resolution_mode { |
| MODE_10BIT, /* 10 bit resolution */ |
| MODE_12BIT /* 12 bit resolution */ |
| }; |
| |
| /* Configuraton register bit fields */ |
| /* CFR0 */ |
| #define PEN_STS_CTRL_MODE (1<<15) |
| #define ADC_STS (1<<14) |
| #define RES_CTRL (1<<13) |
| #define ADC_CLK_4MHZ (0<<11) |
| #define ADC_CLK_2MHZ (1<<11) |
| #define ADC_CLK_1MHZ (2<<11) |
| #define PANEL_VLTG_STB_TIME_0US (0<<8) |
| #define PANEL_VLTG_STB_TIME_100US (1<<8) |
| #define PANEL_VLTG_STB_TIME_500US (2<<8) |
| #define PANEL_VLTG_STB_TIME_1MS (3<<8) |
| #define PANEL_VLTG_STB_TIME_5MS (4<<8) |
| #define PANEL_VLTG_STB_TIME_10MS (5<<8) |
| #define PANEL_VLTG_STB_TIME_50MS (6<<8) |
| #define PANEL_VLTG_STB_TIME_100MS (7<<8) |
| |
| /* CFR2 */ |
| #define PINTS1 (1<<15) |
| #define PINTS0 (1<<14) |
| #define MEDIAN_VAL_FLTR_SIZE_1 (0<<12) |
| #define MEDIAN_VAL_FLTR_SIZE_3 (1<<12) |
| #define MEDIAN_VAL_FLTR_SIZE_7 (2<<12) |
| #define MEDIAN_VAL_FLTR_SIZE_15 (3<<12) |
| #define AVRG_VAL_FLTR_SIZE_1 (0<<10) |
| #define AVRG_VAL_FLTR_SIZE_3_4 (1<<10) |
| #define AVRG_VAL_FLTR_SIZE_7_8 (2<<10) |
| #define AVRG_VAL_FLTR_SIZE_16 (3<<10) |
| #define MAV_FLTR_EN_X (1<<4) |
| #define MAV_FLTR_EN_Y (1<<3) |
| #define MAV_FLTR_EN_Z (1<<2) |
| |
| #define MAX_12BIT ((1 << 12) - 1) |
| #define MEAS_MASK 0xFFF |
| |
| struct ts_event { |
| u16 x; |
| u16 y; |
| u16 z1, z2; |
| }; |
| |
| struct tsc2004 { |
| struct input_dev *input; |
| char phys[32]; |
| struct delayed_work work; |
| |
| struct i2c_client *client; |
| |
| u16 model; |
| u16 x_plate_ohms; |
| |
| bool pendown; |
| int irq; |
| |
| int (*get_pendown_state)(void); |
| void (*clear_penirq)(void); |
| }; |
| |
| static inline int tsc2004_read_word_data(struct tsc2004 *tsc, u8 cmd) |
| { |
| s32 data; |
| u16 val; |
| |
| data = i2c_smbus_read_word_data(tsc->client, cmd); |
| if (data < 0) { |
| dev_err(&tsc->client->dev, "i2c io (read) error: %d\n", data); |
| return data; |
| } |
| |
| /* The protocol and raw data format from i2c interface: |
| * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P |
| * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit]. |
| */ |
| val = swab16(data) >> 4; |
| |
| dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val); |
| |
| return val; |
| } |
| |
| static inline int tsc2004_write_word_data(struct tsc2004 *tsc, u8 cmd, u16 data) |
| { |
| u16 val; |
| |
| val = swab16(data); |
| return i2c_smbus_write_word_data(tsc->client, cmd, val); |
| } |
| |
| static inline int tsc2004_write_cmd(struct tsc2004 *tsc, u8 value) |
| { |
| return i2c_smbus_write_byte(tsc->client, value); |
| } |
| |
| static int tsc2004_prepare_for_reading(struct tsc2004 *ts) |
| { |
| int err; |
| int cmd, data; |
| |
| /* Reset the TSC, configure for 12 bit */ |
| cmd = TSC2004_CMD1(MEAS_X_Y_Z1_Z2, MODE_12BIT, SWRST_TRUE); |
| err = tsc2004_write_cmd(ts, cmd); |
| if (err < 0) |
| return err; |
| |
| /* Enable interrupt for PENIRQ and DAV */ |
| cmd = TSC2004_CMD0(CFR2_REG, PND0_FALSE, WRITE_REG); |
| data = PINTS1 | PINTS0 | MEDIAN_VAL_FLTR_SIZE_15 | |
| AVRG_VAL_FLTR_SIZE_7_8 | MAV_FLTR_EN_X | MAV_FLTR_EN_Y | |
| MAV_FLTR_EN_Z; |
| err = tsc2004_write_word_data(ts, cmd, data); |
| if (err < 0) |
| return err; |
| |
| /* Configure the TSC in TSMode 1 */ |
| cmd = TSC2004_CMD0(CFR0_REG, PND0_FALSE, WRITE_REG); |
| data = PEN_STS_CTRL_MODE | ADC_CLK_2MHZ | PANEL_VLTG_STB_TIME_1MS; |
| err = tsc2004_write_word_data(ts, cmd, data); |
| if (err < 0) |
| return err; |
| |
| /* Enable x, y, z1 and z2 conversion functions */ |
| cmd = TSC2004_CMD1(MEAS_X_Y_Z1_Z2, MODE_12BIT, SWRST_FALSE); |
| err = tsc2004_write_cmd(ts, cmd); |
| if (err < 0) |
| return err; |
| |
| return 0; |
| } |
| |
| static void tsc2004_read_values(struct tsc2004 *tsc, struct ts_event *tc) |
| { |
| int cmd; |
| |
| /* Read X Measurement */ |
| cmd = TSC2004_CMD0(X_REG, PND0_FALSE, READ_REG); |
| tc->x = tsc2004_read_word_data(tsc, cmd); |
| |
| /* Read Y Measurement */ |
| cmd = TSC2004_CMD0(Y_REG, PND0_FALSE, READ_REG); |
| tc->y = tsc2004_read_word_data(tsc, cmd); |
| |
| /* Read Z1 Measurement */ |
| cmd = TSC2004_CMD0(Z1_REG, PND0_FALSE, READ_REG); |
| tc->z1 = tsc2004_read_word_data(tsc, cmd); |
| |
| /* Read Z2 Measurement */ |
| cmd = TSC2004_CMD0(Z2_REG, PND0_FALSE, READ_REG); |
| tc->z2 = tsc2004_read_word_data(tsc, cmd); |
| |
| |
| tc->x &= MEAS_MASK; |
| tc->y &= MEAS_MASK; |
| tc->z1 &= MEAS_MASK; |
| tc->z2 &= MEAS_MASK; |
| |
| /* Prepare for touch readings */ |
| if (tsc2004_prepare_for_reading(tsc) < 0) |
| dev_dbg(&tsc->client->dev, "Failed to prepare TSC for next" |
| "reading\n"); |
| } |
| |
| static u32 tsc2004_calculate_pressure(struct tsc2004 *tsc, struct ts_event *tc) |
| { |
| u32 rt = 0; |
| |
| /* range filtering */ |
| if (tc->x == MAX_12BIT) |
| tc->x = 0; |
| |
| if (likely(tc->x && tc->z1)) { |
| /* compute touch pressure resistance using equation #1 */ |
| rt = tc->z2 - tc->z1; |
| rt *= tc->x; |
| rt *= tsc->x_plate_ohms; |
| rt /= tc->z1; |
| rt = (rt + 2047) >> 12; |
| } |
| |
| return rt; |
| } |
| |
| static void tsc2004_send_up_event(struct tsc2004 *tsc) |
| { |
| struct input_dev *input = tsc->input; |
| |
| dev_dbg(&tsc->client->dev, "UP\n"); |
| |
| input_report_key(input, BTN_TOUCH, 0); |
| input_report_abs(input, ABS_PRESSURE, 0); |
| input_sync(input); |
| } |
| |
| static void tsc2004_work(struct work_struct *work) |
| { |
| struct tsc2004 *ts = |
| container_of(to_delayed_work(work), struct tsc2004, work); |
| struct ts_event tc; |
| u32 rt; |
| |
| /* |
| * NOTE: We can't rely on the pressure to determine the pen down |
| * state, even though 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 |
| * work function by reading the pen signal state (it's a GPIO |
| * and IRQ). Unfortunately such callback is not always available, |
| * in that case we have rely on the pressure anyway. |
| */ |
| if (ts->get_pendown_state) { |
| if (unlikely(!ts->get_pendown_state())) { |
| tsc2004_send_up_event(ts); |
| ts->pendown = false; |
| goto out; |
| } |
| |
| dev_dbg(&ts->client->dev, "pen is still down\n"); |
| } |
| |
| tsc2004_read_values(ts, &tc); |
| |
| rt = tsc2004_calculate_pressure(ts, &tc); |
| if (rt > MAX_12BIT) { |
| /* |
| * 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. |
| */ |
| dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt); |
| goto out; |
| |
| } |
| |
| if (rt) { |
| struct input_dev *input = ts->input; |
| |
| if (!ts->pendown) { |
| dev_dbg(&ts->client->dev, "DOWN\n"); |
| |
| input_report_key(input, BTN_TOUCH, 1); |
| ts->pendown = true; |
| } |
| |
| input_report_abs(input, ABS_X, tc.x); |
| input_report_abs(input, ABS_Y, tc.y); |
| input_report_abs(input, ABS_PRESSURE, rt); |
| |
| input_sync(input); |
| |
| dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n", |
| tc.x, tc.y, rt); |
| |
| } else if (!ts->get_pendown_state && ts->pendown) { |
| /* |
| * We don't have callback to check pendown state, so we |
| * have to assume that since pressure reported is 0 the |
| * pen was lifted up. |
| */ |
| tsc2004_send_up_event(ts); |
| ts->pendown = false; |
| } |
| |
| out: |
| if (ts->pendown) |
| schedule_delayed_work(&ts->work, |
| msecs_to_jiffies(TS_POLL_PERIOD)); |
| else |
| enable_irq(ts->irq); |
| } |
| |
| static irqreturn_t tsc2004_irq(int irq, void *handle) |
| { |
| struct tsc2004 *ts = handle; |
| |
| if (!ts->get_pendown_state || likely(ts->get_pendown_state())) { |
| disable_irq_nosync(ts->irq); |
| schedule_delayed_work(&ts->work, |
| msecs_to_jiffies(TS_POLL_DELAY)); |
| } |
| |
| if (ts->clear_penirq) |
| ts->clear_penirq(); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void tsc2004_free_irq(struct tsc2004 *ts) |
| { |
| free_irq(ts->irq, ts); |
| if (cancel_delayed_work_sync(&ts->work)) { |
| /* |
| * Work was pending, therefore we need to enable |
| * IRQ here to balance the disable_irq() done in the |
| * interrupt handler. |
| */ |
| enable_irq(ts->irq); |
| } |
| } |
| |
| static int __devinit tsc2004_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct tsc2004 *ts; |
| struct tsc2004_platform_data *pdata = pdata = client->dev.platform_data; |
| struct input_dev *input_dev; |
| int err; |
| |
| if (!pdata) { |
| dev_err(&client->dev, "platform data is required!\n"); |
| return -EINVAL; |
| } |
| |
| if (!i2c_check_functionality(client->adapter, |
| I2C_FUNC_SMBUS_READ_WORD_DATA)) |
| return -EIO; |
| |
| ts = kzalloc(sizeof(struct tsc2004), GFP_KERNEL); |
| input_dev = input_allocate_device(); |
| if (!ts || !input_dev) { |
| err = -ENOMEM; |
| goto err_free_mem; |
| } |
| |
| ts->client = client; |
| ts->irq = client->irq; |
| ts->input = input_dev; |
| INIT_DELAYED_WORK(&ts->work, tsc2004_work); |
| |
| ts->model = pdata->model; |
| ts->x_plate_ohms = pdata->x_plate_ohms; |
| ts->get_pendown_state = pdata->get_pendown_state; |
| ts->clear_penirq = pdata->clear_penirq; |
| |
| snprintf(ts->phys, sizeof(ts->phys), |
| "%s/input0", dev_name(&client->dev)); |
| |
| input_dev->name = "TSC2004 Touchscreen"; |
| input_dev->phys = ts->phys; |
| input_dev->id.bustype = BUS_I2C; |
| |
| 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, 0, MAX_12BIT, 0, 0); |
| input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0); |
| input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0); |
| |
| if (pdata->init_platform_hw) |
| pdata->init_platform_hw(); |
| |
| err = request_irq(ts->irq, tsc2004_irq, IRQF_TRIGGER_FALLING, |
| client->dev.driver->name, ts); |
| if (err < 0) { |
| dev_err(&client->dev, "irq %d busy?\n", ts->irq); |
| goto err_free_mem; |
| } |
| |
| /* Prepare for touch readings */ |
| err = tsc2004_prepare_for_reading(ts); |
| if (err < 0) |
| goto err_free_irq; |
| |
| err = input_register_device(input_dev); |
| if (err) |
| goto err_free_irq; |
| |
| i2c_set_clientdata(client, ts); |
| |
| return 0; |
| |
| err_free_irq: |
| tsc2004_free_irq(ts); |
| if (pdata->exit_platform_hw) |
| pdata->exit_platform_hw(); |
| err_free_mem: |
| input_free_device(input_dev); |
| kfree(ts); |
| return err; |
| } |
| |
| static int __devexit tsc2004_remove(struct i2c_client *client) |
| { |
| struct tsc2004 *ts = i2c_get_clientdata(client); |
| struct tsc2004_platform_data *pdata = client->dev.platform_data; |
| |
| tsc2004_free_irq(ts); |
| |
| if (pdata->exit_platform_hw) |
| pdata->exit_platform_hw(); |
| |
| input_unregister_device(ts->input); |
| kfree(ts); |
| |
| return 0; |
| } |
| |
| static struct i2c_device_id tsc2004_idtable[] = { |
| { "tsc2004", 0 }, |
| { } |
| }; |
| |
| MODULE_DEVICE_TABLE(i2c, tsc2004_idtable); |
| |
| static struct i2c_driver tsc2004_driver = { |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = "tsc2004" |
| }, |
| .id_table = tsc2004_idtable, |
| .probe = tsc2004_probe, |
| .remove = __devexit_p(tsc2004_remove), |
| }; |
| |
| static int __init tsc2004_init(void) |
| { |
| return i2c_add_driver(&tsc2004_driver); |
| } |
| |
| static void __exit tsc2004_exit(void) |
| { |
| i2c_del_driver(&tsc2004_driver); |
| } |
| |
| module_init(tsc2004_init); |
| module_exit(tsc2004_exit); |
| |
| MODULE_AUTHOR("Vaibhav Hiremath <hvaibhav@ti.com>"); |
| MODULE_DESCRIPTION("TSC2004 TouchScreen Driver"); |
| MODULE_LICENSE("GPL"); |