/*
* Atmel AT91 and AVR32 continuous touch screen driver for Wolfson WM97xx AC97
* codecs.
*
* Copyright (C) 2008 - 2009 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/wm97xx.h>
#include <linux/timer.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/slab.h>
#define AC97C_ICA 0x10
#define AC97C_CBRHR 0x30
#define AC97C_CBSR 0x38
#define AC97C_CBMR 0x3c
#define AC97C_IER 0x54
#define AC97C_IDR 0x58
#define AC97C_RXRDY (1 << 4)
#define AC97C_OVRUN (1 << 5)
#define AC97C_CMR_SIZE_20 (0 << 16)
#define AC97C_CMR_SIZE_18 (1 << 16)
#define AC97C_CMR_SIZE_16 (2 << 16)
#define AC97C_CMR_SIZE_10 (3 << 16)
#define AC97C_CMR_CEM_LITTLE (1 << 18)
#define AC97C_CMR_CEM_BIG (0 << 18)
#define AC97C_CMR_CENA (1 << 21)
#define AC97C_INT_CBEVT (1 << 4)
#define AC97C_SR_CAEVT (1 << 3)
#define AC97C_CH_MASK(slot) \
(0x7 << (3 * (slot - 3)))
#define AC97C_CH_ASSIGN(slot, channel) \
(AC97C_CHANNEL_##channel << (3 * (slot - 3)))
#define AC97C_CHANNEL_NONE 0x0
#define AC97C_CHANNEL_B 0x2
#define ac97c_writel(chip, reg, val) \
__raw_writel((val), (chip)->regs + AC97C_##reg)
#define ac97c_readl(chip, reg) \
__raw_readl((chip)->regs + AC97C_##reg)
#ifdef CONFIG_CPU_AT32AP700X
#define ATMEL_WM97XX_AC97C_IOMEM (0xfff02800)
#define ATMEL_WM97XX_AC97C_IRQ (29)
#define ATMEL_WM97XX_GPIO_DEFAULT (32+16) /* Pin 16 on port B. */
#else
#error Unknown CPU, this driver only supports AT32AP700X CPUs.
#endif
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;
/*
* Pen sampling frequency (Hz) in continuous mode.
*/
static int cont_rate = 188;
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 = 1;
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");
/*
* GPIO line number.
*
* Set to GPIO number where the signal from the WM97xx device is hooked up.
*/
static int atmel_gpio_line = ATMEL_WM97XX_GPIO_DEFAULT;
module_param(atmel_gpio_line, int, 0);
MODULE_PARM_DESC(atmel_gpio_line, "GPIO line number connected to WM97xx");
struct atmel_wm97xx {
struct wm97xx *wm;
struct timer_list pen_timer;
void __iomem *regs;
unsigned long ac97c_irq;
unsigned long gpio_pen;
unsigned long gpio_irq;
unsigned short x;
unsigned short y;
};
static irqreturn_t atmel_wm97xx_channel_b_interrupt(int irq, void *dev_id)
{
struct atmel_wm97xx *atmel_wm97xx = dev_id;
struct wm97xx *wm = atmel_wm97xx->wm;
int status = ac97c_readl(atmel_wm97xx, CBSR);
irqreturn_t retval = IRQ_NONE;
if (status & AC97C_OVRUN) {
dev_dbg(&wm->touch_dev->dev, "AC97C overrun\n");
ac97c_readl(atmel_wm97xx, CBRHR);
retval = IRQ_HANDLED;
} else if (status & AC97C_RXRDY) {
u16 data;
u16 value;
u16 source;
u16 pen_down;
data = ac97c_readl(atmel_wm97xx, CBRHR);
value = data & 0x0fff;
source = data & WM97XX_ADCSRC_MASK;
pen_down = (data & WM97XX_PEN_DOWN) >> 8;
if (source == WM97XX_ADCSEL_X)
atmel_wm97xx->x = value;
if (source == WM97XX_ADCSEL_Y)
atmel_wm97xx->y = value;
if (!pressure && source == WM97XX_ADCSEL_Y) {
input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
input_report_key(wm->input_dev, BTN_TOUCH, pen_down);
input_sync(wm->input_dev);
} else if (pressure && source == WM97XX_ADCSEL_PRES) {
input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
input_report_abs(wm->input_dev, ABS_PRESSURE, value);
input_report_key(wm->input_dev, BTN_TOUCH, value);
input_sync(wm->input_dev);
}
retval = IRQ_HANDLED;
}
return retval;
}
static void atmel_wm97xx_acc_pen_up(struct wm97xx *wm)
{
struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
struct input_dev *input_dev = wm->input_dev;
int pen_down = gpio_get_value(atmel_wm97xx->gpio_pen);
if (pen_down != 0) {
mod_timer(&atmel_wm97xx->pen_timer,
jiffies + msecs_to_jiffies(1));
} else {
if (pressure)
input_report_abs(input_dev, ABS_PRESSURE, 0);
input_report_key(input_dev, BTN_TOUCH, 0);
input_sync(input_dev);
}
}
static void atmel_wm97xx_pen_timer(unsigned long data)
{
atmel_wm97xx_acc_pen_up((struct wm97xx *)data);
}
static int atmel_wm97xx_acc_startup(struct wm97xx *wm)
{
struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
int idx = 0;
if (wm->ac97 == NULL)
return -ENODEV;
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->touch_dev->dev, "atmel accelerated touchscreen driver, "
"%d samples/sec\n", cinfo[sp_idx].speed);
if (pen_int) {
unsigned long reg;
wm->pen_irq = atmel_wm97xx->gpio_irq;
switch (wm->id) {
case WM9712_ID2: /* Fall through. */
case WM9713_ID2:
/*
* Use GPIO 13 (PEN_DOWN) to assert GPIO line 3
* (PENDOWN).
*/
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_3, WM97XX_GPIO_OUT,
WM97XX_GPIO_POL_HIGH,
WM97XX_GPIO_NOTSTICKY,
WM97XX_GPIO_NOWAKE);
case WM9705_ID2: /* Fall through. */
/*
* Enable touch data slot in AC97 controller channel B.
*/
reg = ac97c_readl(atmel_wm97xx, ICA);
reg &= ~AC97C_CH_MASK(wm->acc_slot);
reg |= AC97C_CH_ASSIGN(wm->acc_slot, B);
ac97c_writel(atmel_wm97xx, ICA, reg);
/*
* Enable channel and interrupt for RXRDY and OVERRUN.
*/
ac97c_writel(atmel_wm97xx, CBMR, AC97C_CMR_CENA
| AC97C_CMR_CEM_BIG
| AC97C_CMR_SIZE_16
| AC97C_OVRUN
| AC97C_RXRDY);
/* Dummy read to empty RXRHR. */
ac97c_readl(atmel_wm97xx, CBRHR);
/*
* Enable interrupt for channel B in the AC97
* controller.
*/
ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
break;
default:
dev_err(&wm->touch_dev->dev, "pen down irq not "
"supported on this device\n");
pen_int = 0;
break;
}
}
return 0;
}
static void atmel_wm97xx_acc_shutdown(struct wm97xx *wm)
{
if (pen_int) {
struct atmel_wm97xx *atmel_wm97xx =
platform_get_drvdata(wm->touch_dev);
unsigned long ica;
switch (wm->id & 0xffff) {
case WM9705_ID2: /* Fall through. */
case WM9712_ID2: /* Fall through. */
case WM9713_ID2:
/* Disable slot and turn off channel B interrupts. */
ica = ac97c_readl(atmel_wm97xx, ICA);
ica &= ~AC97C_CH_MASK(wm->acc_slot);
ac97c_writel(atmel_wm97xx, ICA, ica);
ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
ac97c_writel(atmel_wm97xx, CBMR, 0);
wm->pen_irq = 0;
break;
default:
dev_err(&wm->touch_dev->dev, "unknown codec\n");
break;
}
}
}
static void atmel_wm97xx_irq_enable(struct wm97xx *wm, int enable)
{
/* Intentionally left empty. */
}
static struct wm97xx_mach_ops atmel_mach_ops = {
.acc_enabled = 1,
.acc_pen_up = atmel_wm97xx_acc_pen_up,
.acc_startup = atmel_wm97xx_acc_startup,
.acc_shutdown = atmel_wm97xx_acc_shutdown,
.irq_enable = atmel_wm97xx_irq_enable,
.irq_gpio = WM97XX_GPIO_3,
};
static int __init atmel_wm97xx_probe(struct platform_device *pdev)
{
struct wm97xx *wm = platform_get_drvdata(pdev);
struct atmel_wm97xx *atmel_wm97xx;
int ret;
atmel_wm97xx = kzalloc(sizeof(struct atmel_wm97xx), GFP_KERNEL);
if (!atmel_wm97xx) {
dev_dbg(&pdev->dev, "out of memory\n");
return -ENOMEM;
}
atmel_wm97xx->wm = wm;
atmel_wm97xx->regs = (void *)ATMEL_WM97XX_AC97C_IOMEM;
atmel_wm97xx->ac97c_irq = ATMEL_WM97XX_AC97C_IRQ;
atmel_wm97xx->gpio_pen = atmel_gpio_line;
atmel_wm97xx->gpio_irq = gpio_to_irq(atmel_wm97xx->gpio_pen);
setup_timer(&atmel_wm97xx->pen_timer, atmel_wm97xx_pen_timer,
(unsigned long)wm);
ret = request_irq(atmel_wm97xx->ac97c_irq,
atmel_wm97xx_channel_b_interrupt,
IRQF_SHARED, "atmel-wm97xx-ch-b", atmel_wm97xx);
if (ret) {
dev_dbg(&pdev->dev, "could not request ac97c irq\n");
goto err;
}
platform_set_drvdata(pdev, atmel_wm97xx);
ret = wm97xx_register_mach_ops(wm, &atmel_mach_ops);
if (ret)
goto err_irq;
return ret;
err_irq:
free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
err:
platform_set_drvdata(pdev, NULL);
kfree(atmel_wm97xx);
return ret;
}
static int __exit atmel_wm97xx_remove(struct platform_device *pdev)
{
struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
struct wm97xx *wm = atmel_wm97xx->wm;
ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
del_timer_sync(&atmel_wm97xx->pen_timer);
wm97xx_unregister_mach_ops(wm);
platform_set_drvdata(pdev, NULL);
kfree(atmel_wm97xx);
return 0;
}
#ifdef CONFIG_PM
static int atmel_wm97xx_suspend(struct platform_device *pdev, pm_message_t msg)
{
struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
disable_irq(atmel_wm97xx->gpio_irq);
del_timer_sync(&atmel_wm97xx->pen_timer);
return 0;
}
static int atmel_wm97xx_resume(struct platform_device *pdev)
{
struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
struct wm97xx *wm = atmel_wm97xx->wm;
if (wm->input_dev->users) {
enable_irq(atmel_wm97xx->gpio_irq);
ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
}
return 0;
}
#else
#define atmel_wm97xx_suspend NULL
#define atmel_wm97xx_resume NULL
#endif
static struct platform_driver atmel_wm97xx_driver = {
.remove = __exit_p(atmel_wm97xx_remove),
.driver = {
.name = "wm97xx-touch",
},
.suspend = atmel_wm97xx_suspend,
.resume = atmel_wm97xx_resume,
};
static int __init atmel_wm97xx_init(void)
{
return platform_driver_probe(&atmel_wm97xx_driver, atmel_wm97xx_probe);
}
module_init(atmel_wm97xx_init);
static void __exit atmel_wm97xx_exit(void)
{
platform_driver_unregister(&atmel_wm97xx_driver);
}
module_exit(atmel_wm97xx_exit);
MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");
MODULE_DESCRIPTION("wm97xx continuous touch driver for Atmel AT91 and AVR32");
MODULE_LICENSE("GPL");
