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linux/drivers/input/touchscreen/wm9705.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

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// 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/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");
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