/* * wm9705.c -- Codec driver for Wolfson WM9705 AC97 Codec. * * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. * Author: Liam Girdwood * Parts Copyright : Ian Molton * Andrew Zabolotny * Russell King * * 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 #include #include #include #include #include #include #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 "); MODULE_DESCRIPTION("WM9705 Touch Screen Driver"); MODULE_LICENSE("GPL");