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345 lines
9.0 KiB
345 lines
9.0 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* wm9705.c -- Codec driver for Wolfson WM9705 AC97 Codec. |
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* |
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* Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC. |
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* Author: Liam Girdwood <[email protected]> |
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* Parts Copyright : Ian Molton <[email protected]> |
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* Andrew Zabolotny <[email protected]> |
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* Russell King <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/kernel.h> |
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#include <linux/input.h> |
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#include <linux/delay.h> |
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#include <linux/bitops.h> |
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#include <linux/wm97xx.h> |
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#define TS_NAME "wm97xx" |
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#define WM9705_VERSION "1.00" |
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#define DEFAULT_PRESSURE 0xb0c0 |
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/* |
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* Module parameters |
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*/ |
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/* |
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* Set current used for pressure measurement. |
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* |
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* Set pil = 2 to use 400uA |
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* pil = 1 to use 200uA and |
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* pil = 0 to disable pressure measurement. |
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* |
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* This is used to increase the range of values returned by the adc |
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* when measureing touchpanel pressure. |
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*/ |
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static int pil; |
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module_param(pil, int, 0); |
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MODULE_PARM_DESC(pil, "Set current used for pressure measurement."); |
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/* |
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* Set threshold for pressure measurement. |
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* |
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* Pen down pressure below threshold is ignored. |
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*/ |
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static int pressure = DEFAULT_PRESSURE & 0xfff; |
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module_param(pressure, int, 0); |
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MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement."); |
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/* |
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* Set adc sample delay. |
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* |
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* For accurate touchpanel measurements, some settling time may be |
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* required between the switch matrix applying a voltage across the |
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* touchpanel plate and the ADC sampling the signal. |
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* |
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* This delay can be set by setting delay = n, where n is the array |
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* position of the delay in the array delay_table below. |
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* Long delays > 1ms are supported for completeness, but are not |
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* recommended. |
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*/ |
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static int delay = 4; |
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module_param(delay, int, 0); |
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MODULE_PARM_DESC(delay, "Set adc sample delay."); |
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/* |
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* Pen detect comparator threshold. |
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* |
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* 0 to Vmid in 15 steps, 0 = use zero power comparator with Vmid threshold |
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* i.e. 1 = Vmid/15 threshold |
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* 15 = Vmid/1 threshold |
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* |
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* Adjust this value if you are having problems with pen detect not |
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* detecting any down events. |
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*/ |
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static int pdd = 8; |
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module_param(pdd, int, 0); |
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MODULE_PARM_DESC(pdd, "Set pen detect comparator threshold"); |
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/* |
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* Set adc mask function. |
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* |
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* Sources of glitch noise, such as signals driving an LCD display, may feed |
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* through to the touch screen plates and affect measurement accuracy. In |
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* order to minimise this, a signal may be applied to the MASK pin to delay or |
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* synchronise the sampling. |
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* |
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* 0 = No delay or sync |
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* 1 = High on pin stops conversions |
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* 2 = Edge triggered, edge on pin delays conversion by delay param (above) |
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* 3 = Edge triggered, edge on pin starts conversion after delay param |
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*/ |
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static int mask; |
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module_param(mask, int, 0); |
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MODULE_PARM_DESC(mask, "Set adc mask function."); |
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/* |
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* ADC sample delay times in uS |
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*/ |
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static const int delay_table[] = { |
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21, /* 1 AC97 Link frames */ |
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42, /* 2 */ |
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84, /* 4 */ |
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167, /* 8 */ |
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333, /* 16 */ |
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667, /* 32 */ |
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1000, /* 48 */ |
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1333, /* 64 */ |
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2000, /* 96 */ |
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2667, /* 128 */ |
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3333, /* 160 */ |
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4000, /* 192 */ |
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4667, /* 224 */ |
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5333, /* 256 */ |
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6000, /* 288 */ |
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0 /* No delay, switch matrix always on */ |
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}; |
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/* |
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* Delay after issuing a POLL command. |
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* |
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* The delay is 3 AC97 link frames + the touchpanel settling delay |
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*/ |
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static inline void poll_delay(int d) |
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{ |
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udelay(3 * AC97_LINK_FRAME + delay_table[d]); |
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} |
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/* |
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* set up the physical settings of the WM9705 |
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*/ |
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static void wm9705_phy_init(struct wm97xx *wm) |
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{ |
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u16 dig1 = 0, dig2 = WM97XX_RPR; |
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/* |
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* mute VIDEO and AUX as they share X and Y touchscreen |
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* inputs on the WM9705 |
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*/ |
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wm97xx_reg_write(wm, AC97_AUX, 0x8000); |
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wm97xx_reg_write(wm, AC97_VIDEO, 0x8000); |
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/* touchpanel pressure current*/ |
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if (pil == 2) { |
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dig2 |= WM9705_PIL; |
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dev_dbg(wm->dev, |
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"setting pressure measurement current to 400uA."); |
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} else if (pil) |
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dev_dbg(wm->dev, |
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"setting pressure measurement current to 200uA."); |
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if (!pil) |
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pressure = 0; |
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/* polling mode sample settling delay */ |
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if (delay != 4) { |
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if (delay < 0 || delay > 15) { |
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dev_dbg(wm->dev, "supplied delay out of range."); |
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delay = 4; |
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} |
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} |
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dig1 &= 0xff0f; |
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dig1 |= WM97XX_DELAY(delay); |
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dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.", |
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delay_table[delay]); |
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/* WM9705 pdd */ |
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dig2 |= (pdd & 0x000f); |
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dev_dbg(wm->dev, "setting pdd to Vmid/%d", 1 - (pdd & 0x000f)); |
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/* mask */ |
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dig2 |= ((mask & 0x3) << 4); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); |
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} |
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static void wm9705_dig_enable(struct wm97xx *wm, int enable) |
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{ |
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if (enable) { |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, |
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wm->dig[2] | WM97XX_PRP_DET_DIG); |
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wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */ |
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} else |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, |
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wm->dig[2] & ~WM97XX_PRP_DET_DIG); |
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} |
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static void wm9705_aux_prepare(struct wm97xx *wm) |
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{ |
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memcpy(wm->dig_save, wm->dig, sizeof(wm->dig)); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG); |
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} |
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static void wm9705_dig_restore(struct wm97xx *wm) |
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{ |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]); |
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} |
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static inline int is_pden(struct wm97xx *wm) |
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{ |
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return wm->dig[2] & WM9705_PDEN; |
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} |
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/* |
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* Read a sample from the WM9705 adc in polling mode. |
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*/ |
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static int wm9705_poll_sample(struct wm97xx *wm, int adcsel, int *sample) |
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{ |
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int timeout = 5 * delay; |
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bool wants_pen = adcsel & WM97XX_PEN_DOWN; |
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if (wants_pen && !wm->pen_probably_down) { |
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u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); |
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if (!(data & WM97XX_PEN_DOWN)) |
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return RC_PENUP; |
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wm->pen_probably_down = 1; |
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} |
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/* set up digitiser */ |
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if (wm->mach_ops && wm->mach_ops->pre_sample) |
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wm->mach_ops->pre_sample(adcsel); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, (adcsel & WM97XX_ADCSEL_MASK) |
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| WM97XX_POLL | WM97XX_DELAY(delay)); |
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/* wait 3 AC97 time slots + delay for conversion */ |
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poll_delay(delay); |
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/* wait for POLL to go low */ |
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while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL) |
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&& timeout) { |
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udelay(AC97_LINK_FRAME); |
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timeout--; |
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} |
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if (timeout == 0) { |
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/* If PDEN is set, we can get a timeout when pen goes up */ |
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if (is_pden(wm)) |
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wm->pen_probably_down = 0; |
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else |
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dev_dbg(wm->dev, "adc sample timeout"); |
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return RC_PENUP; |
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} |
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*sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); |
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if (wm->mach_ops && wm->mach_ops->post_sample) |
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wm->mach_ops->post_sample(adcsel); |
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/* check we have correct sample */ |
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if ((*sample ^ adcsel) & WM97XX_ADCSEL_MASK) { |
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dev_dbg(wm->dev, "adc wrong sample, wanted %x got %x", |
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adcsel & WM97XX_ADCSEL_MASK, |
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*sample & WM97XX_ADCSEL_MASK); |
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return RC_PENUP; |
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} |
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if (wants_pen && !(*sample & WM97XX_PEN_DOWN)) { |
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wm->pen_probably_down = 0; |
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return RC_PENUP; |
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} |
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return RC_VALID; |
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} |
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/* |
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* Sample the WM9705 touchscreen in polling mode |
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*/ |
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static int wm9705_poll_touch(struct wm97xx *wm, struct wm97xx_data *data) |
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{ |
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int rc; |
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rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_X | WM97XX_PEN_DOWN, &data->x); |
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if (rc != RC_VALID) |
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return rc; |
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rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_Y | WM97XX_PEN_DOWN, &data->y); |
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if (rc != RC_VALID) |
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return rc; |
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if (pil) { |
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rc = wm9705_poll_sample(wm, WM97XX_ADCSEL_PRES | WM97XX_PEN_DOWN, &data->p); |
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if (rc != RC_VALID) |
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return rc; |
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} else |
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data->p = DEFAULT_PRESSURE; |
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return RC_VALID; |
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} |
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/* |
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* Enable WM9705 continuous mode, i.e. touch data is streamed across |
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* an AC97 slot |
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*/ |
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static int wm9705_acc_enable(struct wm97xx *wm, int enable) |
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{ |
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u16 dig1, dig2; |
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int ret = 0; |
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dig1 = wm->dig[1]; |
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dig2 = wm->dig[2]; |
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if (enable) { |
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/* continuous mode */ |
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if (wm->mach_ops->acc_startup && |
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(ret = wm->mach_ops->acc_startup(wm)) < 0) |
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return ret; |
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dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK | |
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WM97XX_DELAY_MASK | WM97XX_SLT_MASK); |
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dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN | |
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WM97XX_DELAY(delay) | |
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WM97XX_SLT(wm->acc_slot) | |
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WM97XX_RATE(wm->acc_rate); |
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if (pil) |
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dig1 |= WM97XX_ADCSEL_PRES; |
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dig2 |= WM9705_PDEN; |
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} else { |
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dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN); |
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dig2 &= ~WM9705_PDEN; |
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if (wm->mach_ops->acc_shutdown) |
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wm->mach_ops->acc_shutdown(wm); |
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} |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1); |
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wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2); |
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return ret; |
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} |
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struct wm97xx_codec_drv wm9705_codec = { |
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.id = WM9705_ID2, |
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.name = "wm9705", |
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.poll_sample = wm9705_poll_sample, |
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.poll_touch = wm9705_poll_touch, |
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.acc_enable = wm9705_acc_enable, |
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.phy_init = wm9705_phy_init, |
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.dig_enable = wm9705_dig_enable, |
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.dig_restore = wm9705_dig_restore, |
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.aux_prepare = wm9705_aux_prepare, |
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}; |
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EXPORT_SYMBOL_GPL(wm9705_codec); |
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/* Module information */ |
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MODULE_AUTHOR("Liam Girdwood <[email protected]>"); |
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MODULE_DESCRIPTION("WM9705 Touch Screen Driver"); |
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MODULE_LICENSE("GPL");
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