| /* |
| * wm9705.c -- Codec driver for Wolfson WM9705 AC97 Codec. |
| * |
| * Copyright 2003, 2004, 2005, 2006, 2007 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 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; |
| |
| 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 = ((adcsel & 0x7fff) + 3) << 12; |
| |
| if (wm->mach_ops && wm->mach_ops->pre_sample) |
| wm->mach_ops->pre_sample(adcsel); |
| wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, |
| adcsel | 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 & WM97XX_ADCSEL_MASK) != adcsel) { |
| dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel, |
| *sample & WM97XX_ADCSEL_MASK); |
| return RC_PENUP; |
| } |
| |
| if (!(*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, &data->x); |
| if (rc != RC_VALID) |
| return rc; |
| rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_Y, &data->y); |
| if (rc != RC_VALID) |
| return rc; |
| if (pil) { |
| rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_PRES, &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) { |
| /* continous 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 <liam.girdwood@wolfsonmicro.com>"); |
| MODULE_DESCRIPTION("WM9705 Touch Screen Driver"); |
| MODULE_LICENSE("GPL"); |