diff options
Diffstat (limited to 'drivers/input/touchscreen/wm9712.c')
| -rw-r--r-- | drivers/input/touchscreen/wm9712.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/wm9712.c b/drivers/input/touchscreen/wm9712.c new file mode 100644 index 000000000..6947714df --- /dev/null +++ b/drivers/input/touchscreen/wm9712.c @@ -0,0 +1,466 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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> + */ + +#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 resistor 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\n", + 64000 / rpu); + } + + /* WM9712 five wire */ + if (five_wire) { + dig2 |= WM9712_45W; + dev_dbg(wm->dev, "setting 5-wire touchscreen mode.\n"); + + 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.\n"); + } else if (pil) + dev_dbg(wm->dev, + "setting pressure measurement current to 200uA.\n"); + if (!pil) + pressure = 0; + + /* polling mode sample settling delay */ + if (delay < 0 || delay > 15) { + dev_dbg(wm->dev, "supplied delay out of range.\n"); + delay = 4; + } + dig1 &= 0xff0f; + dig1 |= WM97XX_DELAY(delay); + dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.\n", + 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; + 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\n"); + 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\n", + adcsel & WM97XX_ADCSEL_MASK, + *sample & WM97XX_ADCSEL_MASK); + return RC_AGAIN; + } + + if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { + /* Sometimes it reads a wrong value the first time. */ + *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); + 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\n"); + 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 | WM97XX_PEN_DOWN, + &data->x); + if (rc != RC_VALID) + return rc; + + rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, + &data->y); + if (rc != RC_VALID) + return rc; + + if (pil && !five_wire) { + rc = wm9712_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 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) { + /* continuous 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"); |