|  | /* | 
|  | * 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> | 
|  | * | 
|  | *  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/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"); |