// 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");