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Release 4.7 drivers/input/touchscreen/intel-mid-touch.c

/*
 * 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/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>
#include <linux/device.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); }

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/* * 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; }

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Total44100.00%3100.00%

/* * 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; }

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/* * 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); }

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/* 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; }

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/*************************** 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; }

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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; }

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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; }

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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); }

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/* 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; }

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/* Utility to read PMIC ID */
static int 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; }

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/* * 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 mrstouch_chan_parse(struct mrstouch_dev *tsdev) { int found = 0; int err, i; u8 r8; for (i = 0; i < MRSTOUCH_MAX_CHANNELS; i++) { err = intel_scu_ipc_ioread8(PMICADDR0 + i, &r8); if (err) return err; if (r8 == END_OF_CHANNEL) { found = i; break; } } if (tsdev->vendor == PMIC_VENDOR_FS) { if (found > MRSTOUCH_MAX_CHANNELS - 18) return -ENOSPC; } else { if (found > MRSTOUCH_MAX_CHANNELS - 4) return -ENOSPC; } return found; }

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Total111100.00%4100.00%

/* * Writes touch screen channels to ADC address selection registers */
static int 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); }

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Total66100.00%3100.00%

/* Initialize ADC */
static int 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 (continuous 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; }

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/* Probe function for touch screen driver */
static int 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 = devm_kzalloc(&pdev->dev, sizeof(struct mrstouch_dev), GFP_KERNEL); if (!tsdev) { dev_err(&pdev->dev, "unable to allocate memory\n"); return -ENOMEM; } input = devm_input_allocate_device(&pdev->dev); if (!input) { dev_err(&pdev->dev, "unable to allocate input device\n"); return -ENOMEM; } 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"); return err; } 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 = devm_request_threaded_irq(&pdev->dev, tsdev->irq, NULL, mrstouch_pendet_irq, IRQF_ONESHOT, "mrstouch", tsdev); if (err) { dev_err(tsdev->dev, "unable to allocate irq\n"); return err; } err = input_register_device(tsdev->input); if (err) { dev_err(tsdev->dev, "unable to register input device\n"); return err; } return 0; }

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alek dualek du266.55%116.67%
alan coxalan cox30.76%116.67%
lars-peter clausenlars-peter clausen10.25%116.67%
Total397100.00%6100.00%

static struct platform_driver mrstouch_driver = { .driver = { .name = "pmic_touch", }, .probe = mrstouch_probe, }; module_platform_driver(mrstouch_driver); MODULE_AUTHOR("Sreedhara Murthy. D.S, sreedhara.ds@intel.com"); MODULE_DESCRIPTION("Intel Moorestown Resistive Touch Screen Driver"); MODULE_LICENSE("GPL");

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himangi saraogihimangi saraogi522.05%19.09%
alek dualek du341.34%19.09%
arjan van de venarjan van de ven271.06%19.09%
alan coxalan cox120.47%19.09%
andy rossandy ross110.43%19.09%
axel linaxel lin50.20%19.09%
lars-peter clausenlars-peter clausen10.04%19.09%
jj dingjj ding10.04%19.09%
lucas de marchilucas de marchi10.04%19.09%
Total2542100.00%11100.00%
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