// SPDX-License-Identifier: GPL-2.0-or-later/* * wm9705.c  --  Codec driver for Wolfson WM9705 AC97 Codec. * * 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> */ #include <linux/export.h>#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 WM9705_VERSION		"1.00"#define DEFAULT_PRESSURE	0xb0c0 /* * Module parameters */ /* * 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 = 4;module_param(delay, int, 0);MODULE_PARM_DESC(delay, "Set adc sample delay."); /* * Pen detect comparator threshold. * * 0 to Vmid in 15 steps, 0 = use zero power comparator with Vmid threshold * i.e. 1 =  Vmid/15 threshold *      15 =  Vmid/1 threshold * * Adjust this value if you are having problems with pen detect not * detecting any down events. */static int pdd = 8;module_param(pdd, int, 0);MODULE_PARM_DESC(pdd, "Set pen detect comparator threshold"); /* * 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."); /* * 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 WM9705 */static void wm9705_phy_init(struct wm97xx *wm){	u16 dig1 = 0, dig2 = WM97XX_RPR; 	/*	* mute VIDEO and AUX as they share X and Y touchscreen	* inputs on the WM9705	*/	wm97xx_reg_write(wm, AC97_AUX, 0x8000);	wm97xx_reg_write(wm, AC97_VIDEO, 0x8000); 	/* touchpanel pressure current*/	if (pil == 2) {		dig2 |= WM9705_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 != 4) {		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]); 	/* WM9705 pdd */	dig2 |= (pdd & 0x000f);	dev_dbg(wm->dev, "setting pdd to Vmid/%d", 1 - (pdd & 0x000f)); 	/* mask */	dig2 |= ((mask & 0x3) << 4); 	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);} static void wm9705_dig_enable(struct wm97xx *wm, int enable){	if (enable) {		wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,				 wm->dig[2] | WM97XX_PRP_DET_DIG);		wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */	} else		wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,				 wm->dig[2] & ~WM97XX_PRP_DET_DIG);} static void wm9705_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 wm9705_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] & WM9705_PDEN;} /* * Read a sample from the WM9705 adc in polling mode. */static int wm9705_poll_sample(struct wm97xx *wm, int adcsel, int *sample){	int timeout = 5 * delay;	bool wants_pen = adcsel & WM97XX_PEN_DOWN; 	if (wants_pen && !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 (wm->mach_ops && wm->mach_ops->pre_sample)		wm->mach_ops->pre_sample(adcsel);	wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK)				| 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 ^ adcsel) & WM97XX_ADCSEL_MASK) {		dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x",			adcsel & WM97XX_ADCSEL_MASK,			*sample & WM97XX_ADCSEL_MASK);		return RC_PENUP;	} 	if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) {		wm->pen_probably_down = 0;		return RC_PENUP;	} 	return RC_VALID;} /* * Sample the WM9705 touchscreen in polling mode */static int wm9705_poll_touch(struct wm97xx *wm, struct wm97xx_data *data){	int rc; 	rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x);	if (rc != RC_VALID)		return rc;	rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y);	if (rc != RC_VALID)		return rc;	if (pil) {		rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, &data->p);		if (rc != RC_VALID)			return rc;	} else		data->p = DEFAULT_PRESSURE; 	return RC_VALID;} /* * Enable WM9705 continuous mode, i.e. touch data is streamed across * an AC97 slot */static int wm9705_acc_enable(struct wm97xx *wm, int enable){	u16 dig1, dig2;	int ret = 0; 	dig1 = wm->dig[1];	dig2 = wm->dig[2]; 	if (enable) {		/* continuous mode */		if (wm->mach_ops->acc_startup &&		    (ret = wm->mach_ops->acc_startup(wm)) < 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 |= WM9705_PDEN;	} else {		dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN);		dig2 &= ~WM9705_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 ret;} struct wm97xx_codec_drv wm9705_codec = {	.id = WM9705_ID2,	.name = "wm9705",	.poll_sample = wm9705_poll_sample,	.poll_touch = wm9705_poll_touch,	.acc_enable = wm9705_acc_enable,	.phy_init = wm9705_phy_init,	.dig_enable = wm9705_dig_enable,	.dig_restore = wm9705_dig_restore,	.aux_prepare = wm9705_aux_prepare,};EXPORT_SYMBOL_GPL(wm9705_codec); /* Module information */MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");MODULE_DESCRIPTION("WM9705 Touch Screen Driver");MODULE_LICENSE("GPL");