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    Subject[PATCH 4/6] Add chip driver for WM9713 touchscreen
    Date
    Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
    Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
    Signed-off-by: Mike Arthur <mike.arthur@wolfsonmicro.com>
    Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
    Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
    Cc: Stanley Cai <stanley.cai@intel.com>
    Cc: Rodolfo Giometti <giometti@enneenne.com>
    Cc: Russell King <rmk@arm.linux.org.uk>
    Cc: Marc Kleine-Budde <mkl@pengutronix.de>
    Cc: Pete MacKay <linux01@architechnical.net>
    Cc: Ian Molton <spyro@f2s.com>
    Cc: Vince Sanders <vince@kyllikki.org>
    Cc: Andrew Zabolotny <zap@homelink.ru>
    ---
    drivers/input/touchscreen/wm9713.c | 459 ++++++++++++++++++++++++++++++++++++
    1 files changed, 459 insertions(+), 0 deletions(-)
    create mode 100644 drivers/input/touchscreen/wm9713.c

    diff --git a/drivers/input/touchscreen/wm9713.c b/drivers/input/touchscreen/wm9713.c
    new file mode 100644
    index 0000000..5067e59
    --- /dev/null
    +++ b/drivers/input/touchscreen/wm9713.c
    @@ -0,0 +1,459 @@
    +/*
    + * wm9713.c -- Codec touch driver for Wolfson WM9713 AC97 Codec.
    + *
    + * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
    + * Author: Liam Girdwood
    + * liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
    + * 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/version.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 WM9713_VERSION "0.53"
    +#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 = 4;
    +module_param(delay, int, 0);
    +MODULE_PARM_DESC(delay, "Set adc sample delay.");
    +
    +/*
    + * 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 WM9713
    + */
    +static void wm9713_phy_init(struct wm97xx *wm)
    +{
    + u16 dig1 = 0, dig2, dig3;
    +
    + /* default values */
    + dig2 = WM97XX_DELAY(4) | WM97XX_SLT(5);
    + dig3 = WM9712_RPU(1);
    +
    + /* rpu */
    + if (rpu) {
    + dig3 &= 0xffc0;
    + dig3 |= WM9712_RPU(rpu);
    + dev_info(wm->dev, "setting pen detect pull-up to %d Ohms\n",
    + 64000 / rpu);
    + }
    +
    + /* touchpanel pressure */
    + if (pil == 2) {
    + dig3 |= WM9712_PIL;
    + dev_info(wm->dev,
    + "setting pressure measurement current to 400uA.");
    + } else if (pil)
    + dev_info(wm->dev,
    + "setting pressure measurement current to 200uA.");
    + if (!pil)
    + pressure = 0;
    +
    + /* sample settling delay */
    + if (delay < 0 || delay > 15) {
    + dev_info(wm->dev, "supplied delay out of range.");
    + delay = 4;
    + dev_info(wm->dev, "setting adc sample delay to %d u Secs.",
    + delay_table[delay]);
    + }
    + dig2 &= 0xff0f;
    + dig2 |= WM97XX_DELAY(delay);
    +
    + /* mask */
    + dig3 |= ((mask & 0x3) << 4);
    + if (coord)
    + dig3 |= WM9713_WAIT;
    +
    + wm->misc = wm97xx_reg_read(wm, 0x5a);
    +
    + wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
    + wm97xx_reg_write(wm, AC97_GPIO_STICKY, 0x0);
    +}
    +
    +static void wm9713_dig_enable(struct wm97xx *wm, int enable)
    +{
    + u16 val;
    +
    + if (enable) {
    + val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
    + wm97xx_reg_write(wm, AC97_EXTENDED_MID, val & 0x7fff);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] |
    + WM97XX_PRP_DET_DIG);
    + wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
    + } else {
    + wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2] &
    + ~WM97XX_PRP_DET_DIG);
    + val = wm97xx_reg_read(wm, AC97_EXTENDED_MID);
    + wm97xx_reg_write(wm, AC97_EXTENDED_MID, val | 0x8000);
    + }
    +}
    +
    +static void wm9713_dig_restore(struct wm97xx *wm)
    +{
    + wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig_save[0]);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig_save[1]);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig_save[2]);
    +}
    +
    +static void wm9713_aux_prepare(struct wm97xx *wm)
    +{
    + memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
    + wm97xx_reg_write(wm, AC97_WM9713_DIG1, 0);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG2, 0);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG3, WM97XX_PRP_DET_DIG);
    +}
    +
    +static inline int is_pden(struct wm97xx *wm)
    +{
    + return wm->dig[2] & WM9713_PDEN;
    +}
    +
    +/*
    + * Read a sample from the WM9713 adc in polling mode.
    + */
    +static int wm9713_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
    +{
    + u16 dig1;
    + 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 = 1 << ((adcsel & 0x7fff) + 3);
    +
    + dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
    + dig1 &= ~WM9713_ADCSEL_MASK;
    +
    + if (wm->mach_ops && wm->mach_ops->pre_sample)
    + wm->mach_ops->pre_sample(adcsel);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1 | adcsel | WM9713_POLL);
    +
    + /* wait 3 AC97 time slots + delay for conversion */
    + poll_delay(delay);
    +
    + /* wait for POLL to go low */
    + while ((wm97xx_reg_read(wm, AC97_WM9713_DIG1) & WM9713_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_ADCSRC_MASK) != ffs(adcsel >> 1) << 12) {
    + dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
    + *sample & WM97XX_ADCSRC_MASK);
    + return RC_PENUP;
    + }
    +
    + if (!(*sample & WM97XX_PEN_DOWN)) {
    + wm->pen_probably_down = 0;
    + return RC_PENUP;
    + }
    +
    + return RC_VALID;
    +}
    +
    +/*
    + * Read a coordinate from the WM9713 adc in polling mode.
    + */
    +static int wm9713_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
    +{
    + u16 dig1;
    + 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 */
    + dig1 = wm97xx_reg_read(wm, AC97_WM9713_DIG1);
    + dig1 &= ~WM9713_ADCSEL_MASK;
    + if (pil)
    + dig1 |= WM97XX_ADCSEL_PRES;
    +
    + 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_WM9713_DIG1,
    + dig1 | WM9713_POLL | WM9713_COO);
    +
    + /* wait 3 AC97 time slots + delay for conversion */
    + 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_WM9713_DIG1) & WM9713_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 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)) {
    + wm->pen_probably_down = 0;
    + return RC_PENUP;
    + }
    + return RC_VALID;
    +err:
    + return RC_PENUP;
    +}
    +
    +/*
    + * Sample the WM9713 touchscreen in polling mode
    + */
    +static int wm9713_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
    +{
    + int rc;
    +
    + if (coord) {
    + rc = wm9713_poll_coord(wm, data);
    + if (rc != RC_VALID)
    + return rc;
    + } else {
    + rc = wm9713_poll_sample(wm, WM9713_ADCSEL_X, &data->x);
    + if (rc != RC_VALID)
    + return rc;
    + rc = wm9713_poll_sample(wm, WM9713_ADCSEL_Y, &data->y);
    + if (rc != RC_VALID)
    + return rc;
    + if (pil) {
    + rc = wm9713_poll_sample(wm, WM9713_ADCSEL_PRES,
    + &data->p);
    + if (rc != RC_VALID)
    + return rc;
    + } else
    + data->p = DEFAULT_PRESSURE;
    + }
    + return RC_VALID;
    +}
    +
    +/*
    + * Enable WM9713 continuous mode, i.e. touch data is streamed across
    + * an AC97 slot
    + */
    +static int wm9713_acc_enable(struct wm97xx *wm, int enable)
    +{
    + u16 dig1, dig2, dig3;
    + int ret = 0;
    +
    + dig1 = wm->dig[0];
    + dig2 = wm->dig[1];
    + dig3 = wm->dig[2];
    +
    + if (enable) {
    + /* continous mode */
    + if (wm->mach_ops->acc_startup &&
    + (ret = wm->mach_ops->acc_startup(wm)) < 0)
    + return ret;
    +
    + dig1 &= ~WM9713_ADCSEL_MASK;
    + dig1 |= WM9713_CTC | WM9713_COO | WM9713_ADCSEL_X |
    + WM9713_ADCSEL_Y;
    + if (pil)
    + dig1 |= WM9713_ADCSEL_PRES;
    + dig2 &= ~(WM97XX_DELAY_MASK | WM97XX_SLT_MASK |
    + WM97XX_CM_RATE_MASK);
    + dig2 |= WM97XX_SLEN | WM97XX_DELAY(delay) |
    + WM97XX_SLT(wm->acc_slot) | WM97XX_RATE(wm->acc_rate);
    + dig3 |= WM9713_PDEN;
    + } else {
    + dig1 &= ~(WM9713_CTC | WM9713_COO);
    + dig2 &= ~WM97XX_SLEN;
    + dig3 &= ~WM9713_PDEN;
    + if (wm->mach_ops->acc_shutdown)
    + wm->mach_ops->acc_shutdown(wm);
    + }
    +
    + wm97xx_reg_write(wm, AC97_WM9713_DIG1, dig1);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG2, dig2);
    + wm97xx_reg_write(wm, AC97_WM9713_DIG3, dig3);
    + return ret;
    +}
    +
    +struct wm97xx_codec_drv wm9713_codec = {
    + .id = WM9713_ID2,
    + .name = "wm9713",
    + .poll_sample = wm9713_poll_sample,
    + .poll_touch = wm9713_poll_touch,
    + .acc_enable = wm9713_acc_enable,
    + .phy_init = wm9713_phy_init,
    + .dig_enable = wm9713_dig_enable,
    + .dig_restore = wm9713_dig_restore,
    + .aux_prepare = wm9713_aux_prepare,
    +};
    +EXPORT_SYMBOL_GPL(wm9713_codec);
    +
    +/* Module information */
    +MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
    +MODULE_DESCRIPTION("WM9713 Touch Screen Driver");
    +MODULE_LICENSE("GPL");
    --
    1.5.4


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