277 lines
6.8 KiB
C
277 lines
6.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* mainstone-wm97xx.c -- Mainstone Continuous Touch screen driver for
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* Wolfson WM97xx AC97 Codecs.
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*
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* Copyright 2004, 2007 Wolfson Microelectronics PLC.
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* Author: Liam Girdwood <lrg@slimlogic.co.uk>
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* Parts Copyright : Ian Molton <spyro@f2s.com>
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* Andrew Zabolotny <zap@homelink.ru>
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*
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* Notes:
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* This is a wm97xx extended touch driver to capture touch
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* data in a continuous manner on the Intel XScale architecture
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*
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* Features:
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* - codecs supported:- WM9705, WM9712, WM9713
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* - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
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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/delay.h>
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#include <linux/gpio/consumer.h>
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#include <linux/irq.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/soc/pxa/cpu.h>
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#include <linux/wm97xx.h>
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#include <sound/pxa2xx-lib.h>
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#include <asm/mach-types.h>
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struct continuous {
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u16 id; /* codec id */
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u8 code; /* continuous code */
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u8 reads; /* number of coord reads per read cycle */
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u32 speed; /* number of coords per second */
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};
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#define WM_READS(sp) ((sp / HZ) + 1)
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static const struct continuous cinfo[] = {
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{ WM9705_ID2, 0, WM_READS(94), 94 },
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{ WM9705_ID2, 1, WM_READS(188), 188 },
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{ WM9705_ID2, 2, WM_READS(375), 375 },
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{ WM9705_ID2, 3, WM_READS(750), 750 },
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{ WM9712_ID2, 0, WM_READS(94), 94 },
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{ WM9712_ID2, 1, WM_READS(188), 188 },
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{ WM9712_ID2, 2, WM_READS(375), 375 },
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{ WM9712_ID2, 3, WM_READS(750), 750 },
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{ WM9713_ID2, 0, WM_READS(94), 94 },
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{ WM9713_ID2, 1, WM_READS(120), 120 },
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{ WM9713_ID2, 2, WM_READS(154), 154 },
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{ WM9713_ID2, 3, WM_READS(188), 188 },
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};
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/* continuous speed index */
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static int sp_idx;
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static struct gpio_desc *gpiod_irq;
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/*
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* Pen sampling frequency (Hz) in continuous mode.
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*/
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static int cont_rate = 200;
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module_param(cont_rate, int, 0);
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MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
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/*
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* Pen down detection.
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*
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* This driver can either poll or use an interrupt to indicate a pen down
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* event. If the irq request fails then it will fall back to polling mode.
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*/
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static int pen_int;
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module_param(pen_int, int, 0);
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MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
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/*
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* Pressure readback.
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*
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* Set to 1 to read back pen down pressure
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*/
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static int pressure;
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module_param(pressure, int, 0);
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MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
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/*
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* AC97 touch data slot.
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*
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* Touch screen readback data ac97 slot
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*/
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static int ac97_touch_slot = 5;
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module_param(ac97_touch_slot, int, 0);
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MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
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/* flush AC97 slot 5 FIFO on pxa machines */
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static void wm97xx_acc_pen_up(struct wm97xx *wm)
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{
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unsigned int count;
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msleep(1);
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if (cpu_is_pxa27x()) {
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while (pxa2xx_ac97_read_misr() & (1 << 2))
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pxa2xx_ac97_read_modr();
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} else if (cpu_is_pxa3xx()) {
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for (count = 0; count < 16; count++)
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pxa2xx_ac97_read_modr();
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}
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}
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static int wm97xx_acc_pen_down(struct wm97xx *wm)
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{
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u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
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int reads = 0;
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static u16 last, tries;
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/* When the AC97 queue has been drained we need to allow time
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* to buffer up samples otherwise we end up spinning polling
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* for samples. The controller can't have a suitably low
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* threshold set to use the notifications it gives.
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*/
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msleep(1);
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if (tries > 5) {
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tries = 0;
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return RC_PENUP;
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}
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x = pxa2xx_ac97_read_modr();
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if (x == last) {
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tries++;
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return RC_AGAIN;
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}
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last = x;
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do {
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if (reads)
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x = pxa2xx_ac97_read_modr();
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y = pxa2xx_ac97_read_modr();
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if (pressure)
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p = pxa2xx_ac97_read_modr();
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dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
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x, y, p);
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/* are samples valid */
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if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
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(y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
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(p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
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goto up;
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/* coordinate is good */
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tries = 0;
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input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
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input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
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input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
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input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
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input_sync(wm->input_dev);
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reads++;
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} while (reads < cinfo[sp_idx].reads);
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up:
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return RC_PENDOWN | RC_AGAIN;
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}
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static int wm97xx_acc_startup(struct wm97xx *wm)
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{
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int idx = 0, ret = 0;
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/* check we have a codec */
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if (wm->ac97 == NULL)
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return -ENODEV;
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/* Go you big red fire engine */
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for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
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if (wm->id != cinfo[idx].id)
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continue;
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sp_idx = idx;
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if (cont_rate <= cinfo[idx].speed)
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break;
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}
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wm->acc_rate = cinfo[sp_idx].code;
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wm->acc_slot = ac97_touch_slot;
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dev_info(wm->dev,
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"mainstone accelerated touchscreen driver, %d samples/sec\n",
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cinfo[sp_idx].speed);
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if (pen_int) {
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gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN);
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if (IS_ERR(gpiod_irq))
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pen_int = 0;
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}
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if (pen_int) {
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wm->pen_irq = gpiod_to_irq(gpiod_irq);
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irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
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}
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/* codec specific irq config */
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if (pen_int) {
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switch (wm->id) {
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case WM9705_ID2:
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break;
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case WM9712_ID2:
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case WM9713_ID2:
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/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
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wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
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WM97XX_GPIO_POL_HIGH,
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WM97XX_GPIO_STICKY,
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WM97XX_GPIO_WAKE);
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wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
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WM97XX_GPIO_POL_HIGH,
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WM97XX_GPIO_NOTSTICKY,
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WM97XX_GPIO_NOWAKE);
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break;
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default:
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dev_err(wm->dev,
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"pen down irq not supported on this device\n");
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pen_int = 0;
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break;
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}
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}
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return ret;
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}
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static void wm97xx_acc_shutdown(struct wm97xx *wm)
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{
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/* codec specific deconfig */
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if (pen_int) {
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if (gpiod_irq)
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gpiod_put(gpiod_irq);
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wm->pen_irq = 0;
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}
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}
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static struct wm97xx_mach_ops mainstone_mach_ops = {
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.acc_enabled = 1,
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.acc_pen_up = wm97xx_acc_pen_up,
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.acc_pen_down = wm97xx_acc_pen_down,
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.acc_startup = wm97xx_acc_startup,
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.acc_shutdown = wm97xx_acc_shutdown,
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.irq_gpio = WM97XX_GPIO_2,
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};
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static int mainstone_wm97xx_probe(struct platform_device *pdev)
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{
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struct wm97xx *wm = platform_get_drvdata(pdev);
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return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
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}
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static int mainstone_wm97xx_remove(struct platform_device *pdev)
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{
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struct wm97xx *wm = platform_get_drvdata(pdev);
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wm97xx_unregister_mach_ops(wm);
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return 0;
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}
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static struct platform_driver mainstone_wm97xx_driver = {
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.probe = mainstone_wm97xx_probe,
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.remove = mainstone_wm97xx_remove,
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.driver = {
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.name = "wm97xx-touch",
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},
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};
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module_platform_driver(mainstone_wm97xx_driver);
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/* Module information */
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MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
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MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
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MODULE_LICENSE("GPL");
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