drivers/input/touchscreen/mainstone-wm97xx.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
  *                         Wolfson WM97xx AC97 Codecs.
  *
  * Copyright 2004, 2007 Wolfson Microelectronics PLC.
  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
  * Parts Copyright : Ian Molton <spyro@f2s.com>
  *                   Andrew Zabolotny <zap@homelink.ru>
  *
  * Notes:
  *     This is a wm97xx extended touch driver to capture touch
  *     data in a continuous manner on the Intel XScale architecture
  *
  *  Features:
  *       - codecs supported:- WM9705, WM9712, WM9713
  *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
  */

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/soc/pxa/cpu.h>
 #include <linux/wm97xx.h>

 #include <sound/pxa2xx-lib.h>

 #include <asm/mach-types.h>

 struct continuous {
 	u16 id;    /* codec id */
 	u8 code;   /* continuous code */
 	u8 reads;  /* number of coord reads per read cycle */
 	u32 speed; /* number of coords per second */
 };

 #define WM_READS(sp) ((sp / HZ) + 1)

 static const struct continuous cinfo[] = {
 	{ WM9705_ID2, 0, WM_READS(94),  94  },
 	{ WM9705_ID2, 1, WM_READS(188), 188 },
 	{ WM9705_ID2, 2, WM_READS(375), 375 },
 	{ WM9705_ID2, 3, WM_READS(750), 750 },
 	{ WM9712_ID2, 0, WM_READS(94),  94  },
 	{ WM9712_ID2, 1, WM_READS(188), 188 },
 	{ WM9712_ID2, 2, WM_READS(375), 375 },
 	{ WM9712_ID2, 3, WM_READS(750), 750 },
 	{ WM9713_ID2, 0, WM_READS(94),  94  },
 	{ WM9713_ID2, 1, WM_READS(120), 120 },
 	{ WM9713_ID2, 2, WM_READS(154), 154 },
 	{ WM9713_ID2, 3, WM_READS(188), 188 },
 };

 /* continuous speed index */
 static int sp_idx;
 static struct gpio_desc *gpiod_irq;

 /*
  * Pen sampling frequency (Hz) in continuous mode.
  */
 static int cont_rate = 200;
 module_param(cont_rate, int, 0);
 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");

 /*
  * Pen down detection.
  *
  * This driver can either poll or use an interrupt to indicate a pen down
  * event. If the irq request fails then it will fall back to polling mode.
  */
 static int pen_int;
 module_param(pen_int, int, 0);
 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");

 /*
  * Pressure readback.
  *
  * Set to 1 to read back pen down pressure
  */
 static int pressure;
 module_param(pressure, int, 0);
 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");

 /*
  * AC97 touch data slot.
  *
  * Touch screen readback data ac97 slot
  */
 static int ac97_touch_slot = 5;
 module_param(ac97_touch_slot, int, 0);
 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");


 /* flush AC97 slot 5 FIFO on pxa machines */
 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 {
 	unsigned int count;

 	msleep(1);

 	if (cpu_is_pxa27x()) {
 		while (pxa2xx_ac97_read_misr() & (1 << 2))
 			pxa2xx_ac97_read_modr();
 	} else if (cpu_is_pxa3xx()) {
 		for (count = 0; count < 16; count++)
 			pxa2xx_ac97_read_modr();
 	}
 }

 static int wm97xx_acc_pen_down(struct wm97xx *wm)
 {
 	u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
 	int reads = 0;
 	static u16 last, tries;

 	/* When the AC97 queue has been drained we need to allow time
 	 * to buffer up samples otherwise we end up spinning polling
 	 * for samples.  The controller can't have a suitably low
 	 * threshold set to use the notifications it gives.
 	 */
 	msleep(1);

 	if (tries > 5) {
 		tries = 0;
 		return RC_PENUP;
 	}

 	x = pxa2xx_ac97_read_modr();
 	if (x == last) {
 		tries++;
 		return RC_AGAIN;
 	}
 	last = x;
 	do {
 		if (reads)
 			x = pxa2xx_ac97_read_modr();
 		y = pxa2xx_ac97_read_modr();
 		if (pressure)
 			p = pxa2xx_ac97_read_modr();

 		dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 			x, y, p);

 		/* are samples valid */
 		if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 		    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 		    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 			goto up;

 		/* coordinate is good */
 		tries = 0;
 		input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 		input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 		input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 		input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 		input_sync(wm->input_dev);
 		reads++;
 	} while (reads < cinfo[sp_idx].reads);
 up:
 	return RC_PENDOWN | RC_AGAIN;
 }

 static int wm97xx_acc_startup(struct wm97xx *wm)
 {
 	int idx = 0, ret = 0;

 	/* check we have a codec */
 	if (wm->ac97 == NULL)
 		return -ENODEV;

 	/* Go you big red fire engine */
 	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 		if (wm->id != cinfo[idx].id)
 			continue;
 		sp_idx = idx;
 		if (cont_rate <= cinfo[idx].speed)
 			break;
 	}
 	wm->acc_rate = cinfo[sp_idx].code;
 	wm->acc_slot = ac97_touch_slot;
 	dev_info(wm->dev,
 		 "mainstone accelerated touchscreen driver, %d samples/sec\n",
 		 cinfo[sp_idx].speed);

 	if (pen_int) {
 		gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN);
 		if (IS_ERR(gpiod_irq))
 			pen_int = 0;
 	}

 	if (pen_int) {
 		wm->pen_irq = gpiod_to_irq(gpiod_irq);
 		irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 	}

 	/* codec specific irq config */
 	if (pen_int) {
 		switch (wm->id) {
 		case WM9705_ID2:
 			break;
 		case WM9712_ID2:
 		case WM9713_ID2:
 			/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
 			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 					   WM97XX_GPIO_POL_HIGH,
 					   WM97XX_GPIO_STICKY,
 					   WM97XX_GPIO_WAKE);
 			wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 					   WM97XX_GPIO_POL_HIGH,
 					   WM97XX_GPIO_NOTSTICKY,
 					   WM97XX_GPIO_NOWAKE);
 			break;
 		default:
 			dev_err(wm->dev,
 				"pen down irq not supported on this device\n");
 			pen_int = 0;
 			break;
 		}
 	}

 	return ret;
 }

 static void wm97xx_acc_shutdown(struct wm97xx *wm)
 {
 	/* codec specific deconfig */
 	if (pen_int) {
 		if (gpiod_irq)
 			gpiod_put(gpiod_irq);
 		wm->pen_irq = 0;
 	}
 }

 static struct wm97xx_mach_ops mainstone_mach_ops = {
 	.acc_enabled	= 1,
 	.acc_pen_up	= wm97xx_acc_pen_up,
 	.acc_pen_down	= wm97xx_acc_pen_down,
 	.acc_startup	= wm97xx_acc_startup,
 	.acc_shutdown	= wm97xx_acc_shutdown,
 	.irq_gpio	= WM97XX_GPIO_2,
 };

 static int mainstone_wm97xx_probe(struct platform_device *pdev)
 {
 	struct wm97xx *wm = platform_get_drvdata(pdev);

 	return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
 }

 static int mainstone_wm97xx_remove(struct platform_device *pdev)
 {
 	struct wm97xx *wm = platform_get_drvdata(pdev);

 	wm97xx_unregister_mach_ops(wm);

 	return 0;
 }

 static struct platform_driver mainstone_wm97xx_driver = {
 	.probe	= mainstone_wm97xx_probe,
 	.remove	= mainstone_wm97xx_remove,
 	.driver	= {
 		.name	= "wm97xx-touch",
 	},
 };
 module_platform_driver(mainstone_wm97xx_driver);

 /* Module information */
 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* mainstone-wm97xx.c -- Mainstone Continuous Touch screen driver for
	* Wolfson WM97xx AC97 Codecs.
	*
	* Copyright 2004, 2007 Wolfson Microelectronics PLC.
	* Author: Liam Girdwood <lrg@slimlogic.co.uk>
	* Parts Copyright : Ian Molton <spyro@f2s.com>
	* Andrew Zabolotny <zap@homelink.ru>
	*
	* Notes:
	* This is a wm97xx extended touch driver to capture touch
	* data in a continuous manner on the Intel XScale architecture
	*
	* Features:
	* - codecs supported:- WM9705, WM9712, WM9713
	* - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
	*/

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/gpio/consumer.h>
	#include <linux/irq.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/soc/pxa/cpu.h>
	#include <linux/wm97xx.h>

	#include <sound/pxa2xx-lib.h>

	#include <asm/mach-types.h>

	struct continuous {
	u16 id; /* codec id */
	u8 code; /* continuous code */
	u8 reads; /* number of coord reads per read cycle */
	u32 speed; /* number of coords per second */
	};

	#define WM_READS(sp) ((sp / HZ) + 1)

	static const struct continuous cinfo[] = {
	{ WM9705_ID2, 0, WM_READS(94), 94 },
	{ WM9705_ID2, 1, WM_READS(188), 188 },
	{ WM9705_ID2, 2, WM_READS(375), 375 },
	{ WM9705_ID2, 3, WM_READS(750), 750 },
	{ WM9712_ID2, 0, WM_READS(94), 94 },
	{ WM9712_ID2, 1, WM_READS(188), 188 },
	{ WM9712_ID2, 2, WM_READS(375), 375 },
	{ WM9712_ID2, 3, WM_READS(750), 750 },
	{ WM9713_ID2, 0, WM_READS(94), 94 },
	{ WM9713_ID2, 1, WM_READS(120), 120 },
	{ WM9713_ID2, 2, WM_READS(154), 154 },
	{ WM9713_ID2, 3, WM_READS(188), 188 },
	};

	/* continuous speed index */
	static int sp_idx;
	static struct gpio_desc *gpiod_irq;

	/*
	* Pen sampling frequency (Hz) in continuous mode.
	*/
	static int cont_rate = 200;
	module_param(cont_rate, int, 0);
	MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");

	/*
	* Pen down detection.
	*
	* This driver can either poll or use an interrupt to indicate a pen down
	* event. If the irq request fails then it will fall back to polling mode.
	*/
	static int pen_int;
	module_param(pen_int, int, 0);
	MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");

	/*
	* Pressure readback.
	*
	* Set to 1 to read back pen down pressure
	*/
	static int pressure;
	module_param(pressure, int, 0);
	MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");

	/*
	* AC97 touch data slot.
	*
	* Touch screen readback data ac97 slot
	*/
	static int ac97_touch_slot = 5;
	module_param(ac97_touch_slot, int, 0);
	MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");


	/* flush AC97 slot 5 FIFO on pxa machines */
	static void wm97xx_acc_pen_up(struct wm97xx *wm)
	{
	unsigned int count;

	msleep(1);

	if (cpu_is_pxa27x()) {
	while (pxa2xx_ac97_read_misr() & (1 << 2))
	pxa2xx_ac97_read_modr();
	} else if (cpu_is_pxa3xx()) {
	for (count = 0; count < 16; count++)
	pxa2xx_ac97_read_modr();
	}
	}

	static int wm97xx_acc_pen_down(struct wm97xx *wm)
	{
	u16 x, y, p = 0x100 \| WM97XX_ADCSEL_PRES;
	int reads = 0;
	static u16 last, tries;

	/* When the AC97 queue has been drained we need to allow time
	* to buffer up samples otherwise we end up spinning polling
	* for samples. The controller can't have a suitably low
	* threshold set to use the notifications it gives.
	*/
	msleep(1);

	if (tries > 5) {
	tries = 0;
	return RC_PENUP;
	}

	x = pxa2xx_ac97_read_modr();
	if (x == last) {
	tries++;
	return RC_AGAIN;
	}
	last = x;
	do {
	if (reads)
	x = pxa2xx_ac97_read_modr();
	y = pxa2xx_ac97_read_modr();
	if (pressure)
	p = pxa2xx_ac97_read_modr();

	dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
	x, y, p);

	/* are samples valid */
	if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X \|\|
	(y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y \|\|
	(p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
	goto up;

	/* coordinate is good */
	tries = 0;
	input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
	input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
	input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
	input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
	input_sync(wm->input_dev);
	reads++;
	} while (reads < cinfo[sp_idx].reads);
	up:
	return RC_PENDOWN \| RC_AGAIN;
	}

	static int wm97xx_acc_startup(struct wm97xx *wm)
	{
	int idx = 0, ret = 0;

	/* check we have a codec */
	if (wm->ac97 == NULL)
	return -ENODEV;

	/* Go you big red fire engine */
	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
	if (wm->id != cinfo[idx].id)
	continue;
	sp_idx = idx;
	if (cont_rate <= cinfo[idx].speed)
	break;
	}
	wm->acc_rate = cinfo[sp_idx].code;
	wm->acc_slot = ac97_touch_slot;
	dev_info(wm->dev,
	"mainstone accelerated touchscreen driver, %d samples/sec\n",
	cinfo[sp_idx].speed);

	if (pen_int) {
	gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN);
	if (IS_ERR(gpiod_irq))
	pen_int = 0;
	}

	if (pen_int) {
	wm->pen_irq = gpiod_to_irq(gpiod_irq);
	irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
	}

	/* codec specific irq config */
	if (pen_int) {
	switch (wm->id) {
	case WM9705_ID2:
	break;
	case WM9712_ID2:
	case WM9713_ID2:
	/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
	wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
	WM97XX_GPIO_POL_HIGH,
	WM97XX_GPIO_STICKY,
	WM97XX_GPIO_WAKE);
	wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
	WM97XX_GPIO_POL_HIGH,
	WM97XX_GPIO_NOTSTICKY,
	WM97XX_GPIO_NOWAKE);
	break;
	default:
	dev_err(wm->dev,
	"pen down irq not supported on this device\n");
	pen_int = 0;
	break;
	}
	}

	return ret;
	}

	static void wm97xx_acc_shutdown(struct wm97xx *wm)
	{
	/* codec specific deconfig */
	if (pen_int) {
	if (gpiod_irq)
	gpiod_put(gpiod_irq);
	wm->pen_irq = 0;
	}
	}

	static struct wm97xx_mach_ops mainstone_mach_ops = {
	.acc_enabled = 1,
	.acc_pen_up = wm97xx_acc_pen_up,
	.acc_pen_down = wm97xx_acc_pen_down,
	.acc_startup = wm97xx_acc_startup,
	.acc_shutdown = wm97xx_acc_shutdown,
	.irq_gpio = WM97XX_GPIO_2,
	};

	static int mainstone_wm97xx_probe(struct platform_device *pdev)
	{
	struct wm97xx *wm = platform_get_drvdata(pdev);

	return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
	}

	static int mainstone_wm97xx_remove(struct platform_device *pdev)
	{
	struct wm97xx *wm = platform_get_drvdata(pdev);

	wm97xx_unregister_mach_ops(wm);

	return 0;
	}

	static struct platform_driver mainstone_wm97xx_driver = {
	.probe = mainstone_wm97xx_probe,
	.remove = mainstone_wm97xx_remove,
	.driver = {
	.name = "wm97xx-touch",
	},
	};
	module_platform_driver(mainstone_wm97xx_driver);

	/* Module information */
	MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
	MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
	MODULE_LICENSE("GPL");