/* * wm9712.c  --  Codec driver for Wolfson WM9712 AC97 Codecs. * * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. * Author: Liam Girdwood <lrg@slimlogic.co.uk> * Parts Copyright : Ian Molton <spyro@f2s.com> *                   Andrew Zabolotny <zap@homelink.ru> *                   Russell King <rmk@arm.linux.org.uk> * *  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. * */#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/kernel.h>#include <linux/input.h>#include <linux/delay.h>#include <linux/bitops.h>#include <linux/wm97xx.h>#define TS_NAME			"wm97xx"#define WM9712_VERSION		"1.00"#define DEFAULT_PRESSURE	0xb0c0/* * Module parameters *//* * Set internal pull up for pen detect. * * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive) * i.e. pull up resistance = 64k Ohms / rpu. * * Adjust this value if you are having problems with pen detect not * detecting any down event. */static int rpu = 8;module_param(rpu, int, 0);MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");/* * Set current used for pressure measurement. * * Set pil = 2 to use 400uA *     pil = 1 to use 200uA and *     pil = 0 to disable pressure measurement. * * This is used to increase the range of values returned by the adc * when measureing touchpanel pressure. */static int pil;module_param(pil, int, 0);MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");/* * Set threshold for pressure measurement. * * Pen down pressure below threshold is ignored. */static int pressure = DEFAULT_PRESSURE & 0xfff;module_param(pressure, int, 0);MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");/* * Set adc sample delay. * * For accurate touchpanel measurements, some settling time may be * required between the switch matrix applying a voltage across the * touchpanel plate and the ADC sampling the signal. * * This delay can be set by setting delay = n, where n is the array * position of the delay in the array delay_table below. * Long delays > 1ms are supported for completeness, but are not * recommended. */static int delay = 3;module_param(delay, int, 0);MODULE_PARM_DESC(delay, "Set adc sample delay.");/* * Set five_wire = 1 to use a 5 wire touchscreen. * * NOTE: Five wire mode does not allow for readback of pressure. */static int five_wire;module_param(five_wire, int, 0);MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");/* * Set adc mask function. * * Sources of glitch noise, such as signals driving an LCD display, may feed * through to the touch screen plates and affect measurement accuracy. In * order to minimise this, a signal may be applied to the MASK pin to delay or * synchronise the sampling. * * 0 = No delay or sync * 1 = High on pin stops conversions * 2 = Edge triggered, edge on pin delays conversion by delay param (above) * 3 = Edge triggered, edge on pin starts conversion after delay param */static int mask;module_param(mask, int, 0);MODULE_PARM_DESC(mask, "Set adc mask function.");/* * Coordinate Polling Enable. * * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together * for every poll. */static int coord;module_param(coord, int, 0);MODULE_PARM_DESC(coord, "Polling coordinate mode");/* * ADC sample delay times in uS */static const int delay_table[] = {	21,    /* 1 AC97 Link frames */	42,    /* 2 */	84,    /* 4 */	167,   /* 8 */	333,   /* 16 */	667,   /* 32 */	1000,  /* 48 */	1333,  /* 64 */	2000,  /* 96 */	2667,  /* 128 */	3333,  /* 160 */	4000,  /* 192 */	4667,  /* 224 */	5333,  /* 256 */	6000,  /* 288 */	0      /* No delay, switch matrix always on */};/* * Delay after issuing a POLL command. * * The delay is 3 AC97 link frames + the touchpanel settling delay */static inline void poll_delay(int d){	udelay(3 * AC97_LINK_FRAME + delay_table[d]);}/* * set up the physical settings of the WM9712 */static void wm9712_phy_init(struct wm97xx *wm){	u16 dig1 = 0;	u16 dig2 = WM97XX_RPR | WM9712_RPU(1);	/* WM9712 rpu */	if (rpu) {		dig2 &= 0xffc0;		dig2 |= WM9712_RPU(rpu);		dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms",			64000 / rpu);	}	/* WM9712 five wire */	if (five_wire) {		dig2 |= WM9712_45W;		dev_dbg(wm->dev, "setting 5-wire touchscreen mode.");		if (pil) {			dev_warn(wm->dev, "pressure measurement is not "				 "supported in 5-wire mode\n");			pil = 0;		}	}	/* touchpanel pressure current*/	if (pil == 2) {		dig2 |= WM9712_PIL;		dev_dbg(wm->dev,			"setting pressure measurement current to 400uA.");	} else if (pil)		dev_dbg(wm->dev,			"setting pressure measurement current to 200uA.");	if (!pil)		pressure = 0;	/* polling mode sample settling delay */	if (delay < 0 || delay > 15) {		dev_dbg(wm->dev, "supplied delay out of range.");		delay = 4;	}	dig1 &= 0xff0f;	dig1 |= WM97XX_DELAY(delay);	dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.",		delay_table[delay]);	/* mask */	dig2 |= ((mask & 0x3) << 6);	if (mask) {		u16 reg;		/* Set GPIO4 as Mask Pin*/		reg = wm97xx_reg_read(wm, AC97_MISC_AFE);		wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4);		reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);		wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4);	}	/* wait - coord mode */	if (coord)		dig2 |= WM9712_WAIT;	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);}static void wm9712_dig_enable(struct wm97xx *wm, int enable){	u16 dig2 = wm->dig[2];	if (enable) {		wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,				 dig2 | WM97XX_PRP_DET_DIG);		wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */	} else		wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,				 dig2 & ~WM97XX_PRP_DET_DIG);}static void wm9712_aux_prepare(struct wm97xx *wm){	memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG);}static void wm9712_dig_restore(struct wm97xx *wm){	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]);}static inline int is_pden(struct wm97xx *wm){	return wm->dig[2] & WM9712_PDEN;}/* * Read a sample from the WM9712 adc in polling mode. */static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample){	int timeout = 5 * delay;	if (!wm->pen_probably_down) {		u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);		if (!(data & WM97XX_PEN_DOWN))			return RC_PENUP;		wm->pen_probably_down = 1;	}	/* set up digitiser */	if (adcsel & 0x8000)		adcsel = ((adcsel & 0x7fff) + 3) << 12;	if (wm->mach_ops && wm->mach_ops->pre_sample)		wm->mach_ops->pre_sample(adcsel);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,			 adcsel | WM97XX_POLL | WM97XX_DELAY(delay));	/* wait 3 AC97 time slots + delay for conversion */	poll_delay(delay);	/* wait for POLL to go low */	while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)	       && timeout) {		udelay(AC97_LINK_FRAME);		timeout--;	}	if (timeout <= 0) {		/* If PDEN is set, we can get a timeout when pen goes up */		if (is_pden(wm))			wm->pen_probably_down = 0;		else			dev_dbg(wm->dev, "adc sample timeout");		return RC_PENUP;	}	*sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);	if (wm->mach_ops && wm->mach_ops->post_sample)		wm->mach_ops->post_sample(adcsel);	/* check we have correct sample */	if ((*sample & WM97XX_ADCSEL_MASK) != adcsel) {		dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,		*sample & WM97XX_ADCSEL_MASK);		return RC_PENUP;	}	if (!(*sample & WM97XX_PEN_DOWN)) {		wm->pen_probably_down = 0;		return RC_PENUP;	}	return RC_VALID;}/* * Read a coord from the WM9712 adc in polling mode. */static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data){	int timeout = 5 * delay;	if (!wm->pen_probably_down) {		u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);		if (!(data_rd & WM97XX_PEN_DOWN))			return RC_PENUP;		wm->pen_probably_down = 1;	}	/* set up digitiser */	if (wm->mach_ops && wm->mach_ops->pre_sample)		wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,		WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay));	/* wait 3 AC97 time slots + delay for conversion and read x */	poll_delay(delay);	data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);	/* wait for POLL to go low */	while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)	       && timeout) {		udelay(AC97_LINK_FRAME);		timeout--;	}	if (timeout <= 0) {		/* If PDEN is set, we can get a timeout when pen goes up */		if (is_pden(wm))			wm->pen_probably_down = 0;		else			dev_dbg(wm->dev, "adc sample timeout");		return RC_PENUP;	}	/* read back y data */	data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);	if (pil)		data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);	else		data->p = DEFAULT_PRESSURE;	if (wm->mach_ops && wm->mach_ops->post_sample)		wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);	/* check we have correct sample */	if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))		goto err;	if (pil && !(data->p & WM97XX_ADCSEL_PRES))		goto err;	if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {		wm->pen_probably_down = 0;		return RC_PENUP;	}	return RC_VALID;err:	return 0;}/* * Sample the WM9712 touchscreen in polling mode */static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data){	int rc;	if (coord) {		rc = wm9712_poll_coord(wm, data);		if (rc != RC_VALID)			return rc;	} else {		rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X, &data->x);		if (rc != RC_VALID)			return rc;		rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y, &data->y);		if (rc != RC_VALID)			return rc;		if (pil && !five_wire) {			rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES,						&data->p);			if (rc != RC_VALID)				return rc;		} else			data->p = DEFAULT_PRESSURE;	}	return RC_VALID;}/* * Enable WM9712 continuous mode, i.e. touch data is streamed across * an AC97 slot */static int wm9712_acc_enable(struct wm97xx *wm, int enable){	u16 dig1, dig2;	int ret = 0;	dig1 = wm->dig[1];	dig2 = wm->dig[2];	if (enable) {		/* continous mode */		if (wm->mach_ops->acc_startup) {			ret = wm->mach_ops->acc_startup(wm);			if (ret < 0)				return ret;		}		dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK |			WM97XX_DELAY_MASK | WM97XX_SLT_MASK);		dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN |			WM97XX_DELAY(delay) |			WM97XX_SLT(wm->acc_slot) |			WM97XX_RATE(wm->acc_rate);		if (pil)			dig1 |= WM97XX_ADCSEL_PRES;		dig2 |= WM9712_PDEN;	} else {		dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN);		dig2 &= ~WM9712_PDEN;		if (wm->mach_ops->acc_shutdown)			wm->mach_ops->acc_shutdown(wm);	}	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);	return 0;}struct wm97xx_codec_drv wm9712_codec = {	.id = WM9712_ID2,	.name = "wm9712",	.poll_sample = wm9712_poll_sample,	.poll_touch = wm9712_poll_touch,	.acc_enable = wm9712_acc_enable,	.phy_init = wm9712_phy_init,	.dig_enable = wm9712_dig_enable,	.dig_restore = wm9712_dig_restore,	.aux_prepare = wm9712_aux_prepare,};EXPORT_SYMBOL_GPL(wm9712_codec);/* Module information */MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");MODULE_DESCRIPTION("WM9712 Touch Screen Driver");MODULE_LICENSE("GPL");