diff options
Diffstat (limited to 'drivers/input/touchscreen/intel-mid-touch.c')
| -rw-r--r-- | drivers/input/touchscreen/intel-mid-touch.c | 687 |
1 files changed, 687 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/intel-mid-touch.c b/drivers/input/touchscreen/intel-mid-touch.c new file mode 100644 index 0000000..c0307b2 --- /dev/null +++ b/drivers/input/touchscreen/intel-mid-touch.c @@ -0,0 +1,687 @@ +/* + * Intel MID Resistive Touch Screen Driver + * + * Copyright (C) 2008 Intel Corp + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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; version 2 of the License. + * + * 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., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * Questions/Comments/Bug fixes to Sreedhara (sreedhara.ds@intel.com) + * Ramesh Agarwal (ramesh.agarwal@intel.com) + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * TODO: + * review conversion of r/m/w sequences + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/interrupt.h> +#include <linux/err.h> +#include <linux/param.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/irq.h> +#include <linux/delay.h> +#include <asm/intel_scu_ipc.h> + +/* PMIC Interrupt registers */ +#define PMIC_REG_ID1 0x00 /* PMIC ID1 register */ + +/* PMIC Interrupt registers */ +#define PMIC_REG_INT 0x04 /* PMIC interrupt register */ +#define PMIC_REG_MINT 0x05 /* PMIC interrupt mask register */ + +/* ADC Interrupt registers */ +#define PMIC_REG_ADCINT 0x5F /* ADC interrupt register */ +#define PMIC_REG_MADCINT 0x60 /* ADC interrupt mask register */ + +/* ADC Control registers */ +#define PMIC_REG_ADCCNTL1 0x61 /* ADC control register */ + +/* ADC Channel Selection registers */ +#define PMICADDR0 0xA4 +#define END_OF_CHANNEL 0x1F + +/* ADC Result register */ +#define PMIC_REG_ADCSNS0H 0x64 + +/* ADC channels for touch screen */ +#define MRST_TS_CHAN10 0xA /* Touch screen X+ connection */ +#define MRST_TS_CHAN11 0xB /* Touch screen X- connection */ +#define MRST_TS_CHAN12 0xC /* Touch screen Y+ connection */ +#define MRST_TS_CHAN13 0xD /* Touch screen Y- connection */ + +/* Touch screen channel BIAS constants */ +#define MRST_XBIAS 0x20 +#define MRST_YBIAS 0x40 +#define MRST_ZBIAS 0x80 + +/* Touch screen coordinates */ +#define MRST_X_MIN 10 +#define MRST_X_MAX 1024 +#define MRST_X_FUZZ 5 +#define MRST_Y_MIN 10 +#define MRST_Y_MAX 1024 +#define MRST_Y_FUZZ 5 +#define MRST_PRESSURE_MIN 0 +#define MRST_PRESSURE_NOMINAL 50 +#define MRST_PRESSURE_MAX 100 + +#define WAIT_ADC_COMPLETION 10 /* msec */ + +/* PMIC ADC round robin delays */ +#define ADC_LOOP_DELAY0 0x0 /* Continuous loop */ +#define ADC_LOOP_DELAY1 0x1 /* 4.5 ms approximate */ + +/* PMIC Vendor Identifiers */ +#define PMIC_VENDOR_FS 0 /* PMIC vendor FreeScale */ +#define PMIC_VENDOR_MAXIM 1 /* PMIC vendor MAXIM */ +#define PMIC_VENDOR_NEC 2 /* PMIC vendor NEC */ +#define MRSTOUCH_MAX_CHANNELS 32 /* Maximum ADC channels */ + +/* Touch screen device structure */ +struct mrstouch_dev { + struct device *dev; /* device associated with touch screen */ + struct input_dev *input; + char phys[32]; + u16 asr; /* Address selection register */ + int irq; + unsigned int vendor; /* PMIC vendor */ + unsigned int rev; /* PMIC revision */ + + int (*read_prepare)(struct mrstouch_dev *tsdev); + int (*read)(struct mrstouch_dev *tsdev, u16 *x, u16 *y, u16 *z); + int (*read_finish)(struct mrstouch_dev *tsdev); +}; + + +/*************************** NEC and Maxim Interface ************************/ + +static int mrstouch_nec_adc_read_prepare(struct mrstouch_dev *tsdev) +{ + return intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0, 0x20); +} + +/* + * Enables PENDET interrupt. + */ +static int mrstouch_nec_adc_read_finish(struct mrstouch_dev *tsdev) +{ + int err; + + err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x20, 0x20); + if (!err) + err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, 0, 0x05); + + return err; +} + +/* + * Reads PMIC ADC touch screen result + * Reads ADC storage registers for higher 7 and lower 3 bits and + * converts the two readings into a single value and turns off gain bit + */ +static int mrstouch_ts_chan_read(u16 offset, u16 chan, u16 *vp, u16 *vm) +{ + int err; + u16 result; + u32 res; + + result = PMIC_REG_ADCSNS0H + offset; + + if (chan == MRST_TS_CHAN12) + result += 4; + + err = intel_scu_ipc_ioread32(result, &res); + if (err) + return err; + + /* Mash the bits up */ + + *vp = (res & 0xFF) << 3; /* Highest 7 bits */ + *vp |= (res >> 8) & 0x07; /* Lower 3 bits */ + *vp &= 0x3FF; + + res >>= 16; + + *vm = (res & 0xFF) << 3; /* Highest 7 bits */ + *vm |= (res >> 8) & 0x07; /* Lower 3 bits */ + *vm &= 0x3FF; + + return 0; +} + +/* + * Enables X, Y and Z bias values + * Enables YPYM for X channels and XPXM for Y channels + */ +static int mrstouch_ts_bias_set(uint offset, uint bias) +{ + int count; + u16 chan, start; + u16 reg[4]; + u8 data[4]; + + chan = PMICADDR0 + offset; + start = MRST_TS_CHAN10; + + for (count = 0; count <= 3; count++) { + reg[count] = chan++; + data[count] = bias | (start + count); + } + + return intel_scu_ipc_writev(reg, data, 4); +} + +/* To read touch screen channel values */ +static int mrstouch_nec_adc_read(struct mrstouch_dev *tsdev, + u16 *x, u16 *y, u16 *z) +{ + int err; + u16 xm, ym, zm; + + /* configure Y bias for X channels */ + err = mrstouch_ts_bias_set(tsdev->asr, MRST_YBIAS); + if (err) + goto ipc_error; + + msleep(WAIT_ADC_COMPLETION); + + /* read x+ and x- channels */ + err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, x, &xm); + if (err) + goto ipc_error; + + /* configure x bias for y channels */ + err = mrstouch_ts_bias_set(tsdev->asr, MRST_XBIAS); + if (err) + goto ipc_error; + + msleep(WAIT_ADC_COMPLETION); + + /* read y+ and y- channels */ + err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN12, y, &ym); + if (err) + goto ipc_error; + + /* configure z bias for x and y channels */ + err = mrstouch_ts_bias_set(tsdev->asr, MRST_ZBIAS); + if (err) + goto ipc_error; + + msleep(WAIT_ADC_COMPLETION); + + /* read z+ and z- channels */ + err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, z, &zm); + if (err) + goto ipc_error; + + return 0; + +ipc_error: + dev_err(tsdev->dev, "ipc error during adc read\n"); + return err; +} + + +/*************************** Freescale Interface ************************/ + +static int mrstouch_fs_adc_read_prepare(struct mrstouch_dev *tsdev) +{ + int err, count; + u16 chan; + u16 reg[5]; + u8 data[5]; + + /* Stop the ADC */ + err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x00, 0x02); + if (err) + goto ipc_error; + + chan = PMICADDR0 + tsdev->asr; + + /* Set X BIAS */ + for (count = 0; count <= 3; count++) { + reg[count] = chan++; + data[count] = 0x2A; + } + reg[count] = chan++; /* Dummy */ + data[count] = 0; + + err = intel_scu_ipc_writev(reg, data, 5); + if (err) + goto ipc_error; + + msleep(WAIT_ADC_COMPLETION); + + /* Set Y BIAS */ + for (count = 0; count <= 3; count++) { + reg[count] = chan++; + data[count] = 0x4A; + } + reg[count] = chan++; /* Dummy */ + data[count] = 0; + + err = intel_scu_ipc_writev(reg, data, 5); + if (err) + goto ipc_error; + + msleep(WAIT_ADC_COMPLETION); + + /* Set Z BIAS */ + err = intel_scu_ipc_iowrite32(chan + 2, 0x8A8A8A8A); + if (err) + goto ipc_error; + + msleep(WAIT_ADC_COMPLETION); + + return 0; + +ipc_error: + dev_err(tsdev->dev, "ipc error during %s\n", __func__); + return err; +} + +static int mrstouch_fs_adc_read(struct mrstouch_dev *tsdev, + u16 *x, u16 *y, u16 *z) +{ + int err; + u16 result; + u16 reg[4]; + u8 data[4]; + + result = PMIC_REG_ADCSNS0H + tsdev->asr; + + reg[0] = result + 4; + reg[1] = result + 5; + reg[2] = result + 16; + reg[3] = result + 17; + + err = intel_scu_ipc_readv(reg, data, 4); + if (err) + goto ipc_error; + + *x = data[0] << 3; /* Higher 7 bits */ + *x |= data[1] & 0x7; /* Lower 3 bits */ + *x &= 0x3FF; + + *y = data[2] << 3; /* Higher 7 bits */ + *y |= data[3] & 0x7; /* Lower 3 bits */ + *y &= 0x3FF; + + /* Read Z value */ + reg[0] = result + 28; + reg[1] = result + 29; + + err = intel_scu_ipc_readv(reg, data, 4); + if (err) + goto ipc_error; + + *z = data[0] << 3; /* Higher 7 bits */ + *z |= data[1] & 0x7; /* Lower 3 bits */ + *z &= 0x3FF; + + return 0; + +ipc_error: + dev_err(tsdev->dev, "ipc error during %s\n", __func__); + return err; +} + +static int mrstouch_fs_adc_read_finish(struct mrstouch_dev *tsdev) +{ + int err, count; + u16 chan; + u16 reg[5]; + u8 data[5]; + + /* Clear all TS channels */ + chan = PMICADDR0 + tsdev->asr; + for (count = 0; count <= 4; count++) { + reg[count] = chan++; + data[count] = 0; + } + err = intel_scu_ipc_writev(reg, data, 5); + if (err) + goto ipc_error; + + for (count = 0; count <= 4; count++) { + reg[count] = chan++; + data[count] = 0; + } + err = intel_scu_ipc_writev(reg, data, 5); + if (err) + goto ipc_error; + + err = intel_scu_ipc_iowrite32(chan + 2, 0x00000000); + if (err) + goto ipc_error; + + /* Start ADC */ + err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x02, 0x02); + if (err) + goto ipc_error; + + return 0; + +ipc_error: + dev_err(tsdev->dev, "ipc error during %s\n", __func__); + return err; +} + +static void mrstouch_report_event(struct input_dev *input, + unsigned int x, unsigned int y, unsigned int z) +{ + if (z > MRST_PRESSURE_NOMINAL) { + /* Pen touched, report button touch and coordinates */ + input_report_key(input, BTN_TOUCH, 1); + input_report_abs(input, ABS_X, x); + input_report_abs(input, ABS_Y, y); + } else { + input_report_key(input, BTN_TOUCH, 0); + } + + input_report_abs(input, ABS_PRESSURE, z); + input_sync(input); +} + +/* PENDET interrupt handler */ +static irqreturn_t mrstouch_pendet_irq(int irq, void *dev_id) +{ + struct mrstouch_dev *tsdev = dev_id; + u16 x, y, z; + + /* + * Should we lower thread priority? Probably not, since we are + * not spinning but sleeping... + */ + + if (tsdev->read_prepare(tsdev)) + goto out; + + do { + if (tsdev->read(tsdev, &x, &y, &z)) + break; + + mrstouch_report_event(tsdev->input, x, y, z); + } while (z > MRST_PRESSURE_NOMINAL); + + tsdev->read_finish(tsdev); + +out: + return IRQ_HANDLED; +} + +/* Utility to read PMIC ID */ +static int __devinit mrstouch_read_pmic_id(uint *vendor, uint *rev) +{ + int err; + u8 r; + + err = intel_scu_ipc_ioread8(PMIC_REG_ID1, &r); + if (err) + return err; + + *vendor = r & 0x7; + *rev = (r >> 3) & 0x7; + + return 0; +} + +/* + * Parse ADC channels to find end of the channel configured by other ADC user + * NEC and MAXIM requires 4 channels and FreeScale needs 18 channels + */ +static int __devinit mrstouch_chan_parse(struct mrstouch_dev *tsdev) +{ + int err, i, found; + u8 r8; + + found = -1; + + for (i = 0; i < MRSTOUCH_MAX_CHANNELS; i++) { + if (found >= 0) + break; + + err = intel_scu_ipc_ioread8(PMICADDR0 + i, &r8); + if (err) + return err; + + if (r8 == END_OF_CHANNEL) { + found = i; + break; + } + } + if (found < 0) + return 0; + + if (tsdev->vendor == PMIC_VENDOR_FS) { + if (found && found > (MRSTOUCH_MAX_CHANNELS - 18)) + return -ENOSPC; + } else { + if (found && found > (MRSTOUCH_MAX_CHANNELS - 4)) + return -ENOSPC; + } + return found; +} + + +/* + * Writes touch screen channels to ADC address selection registers + */ +static int __devinit mrstouch_ts_chan_set(uint offset) +{ + u16 chan; + + int ret, count; + + chan = PMICADDR0 + offset; + for (count = 0; count <= 3; count++) { + ret = intel_scu_ipc_iowrite8(chan++, MRST_TS_CHAN10 + count); + if (ret) + return ret; + } + return intel_scu_ipc_iowrite8(chan++, END_OF_CHANNEL); +} + +/* Initialize ADC */ +static int __devinit mrstouch_adc_init(struct mrstouch_dev *tsdev) +{ + int err, start; + u8 ra, rm; + + err = mrstouch_read_pmic_id(&tsdev->vendor, &tsdev->rev); + if (err) { + dev_err(tsdev->dev, "Unable to read PMIC id\n"); + return err; + } + + switch (tsdev->vendor) { + case PMIC_VENDOR_NEC: + case PMIC_VENDOR_MAXIM: + tsdev->read_prepare = mrstouch_nec_adc_read_prepare; + tsdev->read = mrstouch_nec_adc_read; + tsdev->read_finish = mrstouch_nec_adc_read_finish; + break; + + case PMIC_VENDOR_FS: + tsdev->read_prepare = mrstouch_fs_adc_read_prepare; + tsdev->read = mrstouch_fs_adc_read; + tsdev->read_finish = mrstouch_fs_adc_read_finish; + break; + + default: + dev_err(tsdev->dev, + "Unsupported touchscreen: %d\n", tsdev->vendor); + return -ENXIO; + } + + start = mrstouch_chan_parse(tsdev); + if (start < 0) { + dev_err(tsdev->dev, "Unable to parse channels\n"); + return start; + } + + tsdev->asr = start; + + /* + * ADC power on, start, enable PENDET and set loop delay + * ADC loop delay is set to 4.5 ms approximately + * Loop delay more than this results in jitter in adc readings + * Setting loop delay to 0 (continous loop) in MAXIM stops PENDET + * interrupt generation sometimes. + */ + + if (tsdev->vendor == PMIC_VENDOR_FS) { + ra = 0xE0 | ADC_LOOP_DELAY0; + rm = 0x5; + } else { + /* NEC and MAXIm not consistent with loop delay 0 */ + ra = 0xE0 | ADC_LOOP_DELAY1; + rm = 0x0; + + /* configure touch screen channels */ + err = mrstouch_ts_chan_set(tsdev->asr); + if (err) + return err; + } + + err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, ra, 0xE7); + if (err) + return err; + + err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, rm, 0x03); + if (err) + return err; + + return 0; +} + + +/* Probe function for touch screen driver */ +static int __devinit mrstouch_probe(struct platform_device *pdev) +{ + struct mrstouch_dev *tsdev; + struct input_dev *input; + int err; + int irq; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no interrupt assigned\n"); + return -EINVAL; + } + + tsdev = kzalloc(sizeof(struct mrstouch_dev), GFP_KERNEL); + input = input_allocate_device(); + if (!tsdev || !input) { + dev_err(&pdev->dev, "unable to allocate memory\n"); + err = -ENOMEM; + goto err_free_mem; + } + + tsdev->dev = &pdev->dev; + tsdev->input = input; + tsdev->irq = irq; + + snprintf(tsdev->phys, sizeof(tsdev->phys), + "%s/input0", dev_name(tsdev->dev)); + + err = mrstouch_adc_init(tsdev); + if (err) { + dev_err(&pdev->dev, "ADC initialization failed\n"); + goto err_free_mem; + } + + input->name = "mrst_touchscreen"; + input->phys = tsdev->phys; + input->dev.parent = tsdev->dev; + + input->id.vendor = tsdev->vendor; + input->id.version = tsdev->rev; + + input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + + input_set_abs_params(tsdev->input, ABS_X, + MRST_X_MIN, MRST_X_MAX, MRST_X_FUZZ, 0); + input_set_abs_params(tsdev->input, ABS_Y, + MRST_Y_MIN, MRST_Y_MAX, MRST_Y_FUZZ, 0); + input_set_abs_params(tsdev->input, ABS_PRESSURE, + MRST_PRESSURE_MIN, MRST_PRESSURE_MAX, 0, 0); + + err = request_threaded_irq(tsdev->irq, NULL, mrstouch_pendet_irq, + 0, "mrstouch", tsdev); + if (err) { + dev_err(tsdev->dev, "unable to allocate irq\n"); + goto err_free_mem; + } + + err = input_register_device(tsdev->input); + if (err) { + dev_err(tsdev->dev, "unable to register input device\n"); + goto err_free_irq; + } + + platform_set_drvdata(pdev, tsdev); + return 0; + +err_free_irq: + free_irq(tsdev->irq, tsdev); +err_free_mem: + input_free_device(input); + kfree(tsdev); + return err; +} + +static int __devexit mrstouch_remove(struct platform_device *pdev) +{ + struct mrstouch_dev *tsdev = platform_get_drvdata(pdev); + + free_irq(tsdev->irq, tsdev); + input_unregister_device(tsdev->input); + kfree(tsdev); + + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver mrstouch_driver = { + .driver = { + .name = "pmic_touch", + .owner = THIS_MODULE, + }, + .probe = mrstouch_probe, + .remove = __devexit_p(mrstouch_remove), +}; + +static int __init mrstouch_init(void) +{ + return platform_driver_register(&mrstouch_driver); +} +module_init(mrstouch_init); + +static void __exit mrstouch_exit(void) +{ + platform_driver_unregister(&mrstouch_driver); +} +module_exit(mrstouch_exit); + +MODULE_AUTHOR("Sreedhara Murthy. D.S, sreedhara.ds@intel.com"); +MODULE_DESCRIPTION("Intel Moorestown Resistive Touch Screen Driver"); +MODULE_LICENSE("GPL"); |