linux/drivers/input/touchscreen/imx6ul_tsc.c

586 lines
14 KiB
C

/*
* Freescale i.MX6UL touchscreen controller driver
*
* Copyright (C) 2015 Freescale Semiconductor, Inc.
*
* 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/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/log2.h>
/* ADC configuration registers field define */
#define ADC_AIEN (0x1 << 7)
#define ADC_CONV_DISABLE 0x1F
#define ADC_AVGE (0x1 << 5)
#define ADC_CAL (0x1 << 7)
#define ADC_CALF 0x2
#define ADC_12BIT_MODE (0x2 << 2)
#define ADC_CONV_MODE_MASK (0x3 << 2)
#define ADC_IPG_CLK 0x00
#define ADC_INPUT_CLK_MASK 0x3
#define ADC_CLK_DIV_8 (0x03 << 5)
#define ADC_CLK_DIV_MASK (0x3 << 5)
#define ADC_SHORT_SAMPLE_MODE (0x0 << 4)
#define ADC_SAMPLE_MODE_MASK (0x1 << 4)
#define ADC_HARDWARE_TRIGGER (0x1 << 13)
#define ADC_AVGS_SHIFT 14
#define ADC_AVGS_MASK (0x3 << 14)
#define SELECT_CHANNEL_4 0x04
#define SELECT_CHANNEL_1 0x01
#define DISABLE_CONVERSION_INT (0x0 << 7)
/* ADC registers */
#define REG_ADC_HC0 0x00
#define REG_ADC_HC1 0x04
#define REG_ADC_HC2 0x08
#define REG_ADC_HC3 0x0C
#define REG_ADC_HC4 0x10
#define REG_ADC_HS 0x14
#define REG_ADC_R0 0x18
#define REG_ADC_CFG 0x2C
#define REG_ADC_GC 0x30
#define REG_ADC_GS 0x34
#define ADC_TIMEOUT msecs_to_jiffies(100)
/* TSC registers */
#define REG_TSC_BASIC_SETING 0x00
#define REG_TSC_PRE_CHARGE_TIME 0x10
#define REG_TSC_FLOW_CONTROL 0x20
#define REG_TSC_MEASURE_VALUE 0x30
#define REG_TSC_INT_EN 0x40
#define REG_TSC_INT_SIG_EN 0x50
#define REG_TSC_INT_STATUS 0x60
#define REG_TSC_DEBUG_MODE 0x70
#define REG_TSC_DEBUG_MODE2 0x80
/* TSC configuration registers field define */
#define DETECT_4_WIRE_MODE (0x0 << 4)
#define AUTO_MEASURE 0x1
#define MEASURE_SIGNAL 0x1
#define DETECT_SIGNAL (0x1 << 4)
#define VALID_SIGNAL (0x1 << 8)
#define MEASURE_INT_EN 0x1
#define MEASURE_SIG_EN 0x1
#define VALID_SIG_EN (0x1 << 8)
#define DE_GLITCH_2 (0x2 << 29)
#define START_SENSE (0x1 << 12)
#define TSC_DISABLE (0x1 << 16)
#define DETECT_MODE 0x2
struct imx6ul_tsc {
struct device *dev;
struct input_dev *input;
void __iomem *tsc_regs;
void __iomem *adc_regs;
struct clk *tsc_clk;
struct clk *adc_clk;
struct gpio_desc *xnur_gpio;
u32 measure_delay_time;
u32 pre_charge_time;
bool average_enable;
u32 average_select;
struct completion completion;
};
/*
* TSC module need ADC to get the measure value. So
* before config TSC, we should initialize ADC module.
*/
static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
{
u32 adc_hc = 0;
u32 adc_gc;
u32 adc_gs;
u32 adc_cfg;
unsigned long timeout;
reinit_completion(&tsc->completion);
adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
if (tsc->average_enable) {
adc_cfg &= ~ADC_AVGS_MASK;
adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
}
adc_cfg &= ~ADC_HARDWARE_TRIGGER;
writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
/* enable calibration interrupt */
adc_hc |= ADC_AIEN;
adc_hc |= ADC_CONV_DISABLE;
writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
/* start ADC calibration */
adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
adc_gc |= ADC_CAL;
if (tsc->average_enable)
adc_gc |= ADC_AVGE;
writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
timeout = wait_for_completion_timeout
(&tsc->completion, ADC_TIMEOUT);
if (timeout == 0) {
dev_err(tsc->dev, "Timeout for adc calibration\n");
return -ETIMEDOUT;
}
adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
if (adc_gs & ADC_CALF) {
dev_err(tsc->dev, "ADC calibration failed\n");
return -EINVAL;
}
/* TSC need the ADC work in hardware trigger */
adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
adc_cfg |= ADC_HARDWARE_TRIGGER;
writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
return 0;
}
/*
* This is a TSC workaround. Currently TSC misconnect two
* ADC channels, this function remap channel configure for
* hardware trigger.
*/
static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
{
u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
adc_hc0 = DISABLE_CONVERSION_INT;
writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
adc_hc2 = DISABLE_CONVERSION_INT;
writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
adc_hc4 = DISABLE_CONVERSION_INT;
writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
}
/*
* TSC setting, confige the pre-charge time and measure delay time.
* different touch screen may need different pre-charge time and
* measure delay time.
*/
static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
{
u32 basic_setting = 0;
u32 start;
basic_setting |= tsc->measure_delay_time << 8;
basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
writel(MEASURE_SIG_EN | VALID_SIG_EN,
tsc->tsc_regs + REG_TSC_INT_SIG_EN);
/* start sense detection */
start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
start |= START_SENSE;
start &= ~TSC_DISABLE;
writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
}
static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
{
int err;
err = imx6ul_adc_init(tsc);
if (err)
return err;
imx6ul_tsc_channel_config(tsc);
imx6ul_tsc_set(tsc);
return 0;
}
static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
{
u32 tsc_flow;
u32 adc_cfg;
/* TSC controller enters to idle status */
tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
tsc_flow |= TSC_DISABLE;
writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
/* ADC controller enters to stop mode */
adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
adc_cfg |= ADC_CONV_DISABLE;
writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
}
/* Delay some time (max 2ms), wait the pre-charge done. */
static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
{
unsigned long timeout = jiffies + msecs_to_jiffies(2);
u32 state_machine;
u32 debug_mode2;
do {
if (time_after(jiffies, timeout))
return false;
usleep_range(200, 400);
debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
state_machine = (debug_mode2 >> 20) & 0x7;
} while (state_machine != DETECT_MODE);
usleep_range(200, 400);
return true;
}
static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
{
struct imx6ul_tsc *tsc = dev_id;
u32 status;
u32 value;
u32 x, y;
u32 start;
status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
/* write 1 to clear the bit measure-signal */
writel(MEASURE_SIGNAL | DETECT_SIGNAL,
tsc->tsc_regs + REG_TSC_INT_STATUS);
/* It's a HW self-clean bit. Set this bit and start sense detection */
start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
start |= START_SENSE;
writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
if (status & MEASURE_SIGNAL) {
value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
x = (value >> 16) & 0x0fff;
y = value & 0x0fff;
/*
* In detect mode, we can get the xnur gpio value,
* otherwise assume contact is stiull active.
*/
if (!tsc_wait_detect_mode(tsc) ||
gpiod_get_value_cansleep(tsc->xnur_gpio)) {
input_report_key(tsc->input, BTN_TOUCH, 1);
input_report_abs(tsc->input, ABS_X, x);
input_report_abs(tsc->input, ABS_Y, y);
} else {
input_report_key(tsc->input, BTN_TOUCH, 0);
}
input_sync(tsc->input);
}
return IRQ_HANDLED;
}
static irqreturn_t adc_irq_fn(int irq, void *dev_id)
{
struct imx6ul_tsc *tsc = dev_id;
u32 coco;
u32 value;
coco = readl(tsc->adc_regs + REG_ADC_HS);
if (coco & 0x01) {
value = readl(tsc->adc_regs + REG_ADC_R0);
complete(&tsc->completion);
}
return IRQ_HANDLED;
}
static int imx6ul_tsc_open(struct input_dev *input_dev)
{
struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
int err;
err = clk_prepare_enable(tsc->adc_clk);
if (err) {
dev_err(tsc->dev,
"Could not prepare or enable the adc clock: %d\n",
err);
return err;
}
err = clk_prepare_enable(tsc->tsc_clk);
if (err) {
dev_err(tsc->dev,
"Could not prepare or enable the tsc clock: %d\n",
err);
goto disable_adc_clk;
}
err = imx6ul_tsc_init(tsc);
if (err)
goto disable_tsc_clk;
return 0;
disable_tsc_clk:
clk_disable_unprepare(tsc->tsc_clk);
disable_adc_clk:
clk_disable_unprepare(tsc->adc_clk);
return err;
}
static void imx6ul_tsc_close(struct input_dev *input_dev)
{
struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
imx6ul_tsc_disable(tsc);
clk_disable_unprepare(tsc->tsc_clk);
clk_disable_unprepare(tsc->adc_clk);
}
static int imx6ul_tsc_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct imx6ul_tsc *tsc;
struct input_dev *input_dev;
struct resource *tsc_mem;
struct resource *adc_mem;
int err;
int tsc_irq;
int adc_irq;
u32 average_samples;
tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
if (!tsc)
return -ENOMEM;
input_dev = devm_input_allocate_device(&pdev->dev);
if (!input_dev)
return -ENOMEM;
input_dev->name = "iMX6UL Touchscreen Controller";
input_dev->id.bustype = BUS_HOST;
input_dev->open = imx6ul_tsc_open;
input_dev->close = imx6ul_tsc_close;
input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);
input_set_drvdata(input_dev, tsc);
tsc->dev = &pdev->dev;
tsc->input = input_dev;
init_completion(&tsc->completion);
tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN);
if (IS_ERR(tsc->xnur_gpio)) {
err = PTR_ERR(tsc->xnur_gpio);
dev_err(&pdev->dev,
"failed to request GPIO tsc_X- (xnur): %d\n", err);
return err;
}
tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
if (IS_ERR(tsc->tsc_regs)) {
err = PTR_ERR(tsc->tsc_regs);
dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
return err;
}
adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
if (IS_ERR(tsc->adc_regs)) {
err = PTR_ERR(tsc->adc_regs);
dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
return err;
}
tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
if (IS_ERR(tsc->tsc_clk)) {
err = PTR_ERR(tsc->tsc_clk);
dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
return err;
}
tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
if (IS_ERR(tsc->adc_clk)) {
err = PTR_ERR(tsc->adc_clk);
dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
return err;
}
tsc_irq = platform_get_irq(pdev, 0);
if (tsc_irq < 0) {
dev_err(&pdev->dev, "no tsc irq resource?\n");
return tsc_irq;
}
adc_irq = platform_get_irq(pdev, 1);
if (adc_irq < 0) {
dev_err(&pdev->dev, "no adc irq resource?\n");
return adc_irq;
}
err = devm_request_threaded_irq(tsc->dev, tsc_irq,
NULL, tsc_irq_fn, IRQF_ONESHOT,
dev_name(&pdev->dev), tsc);
if (err) {
dev_err(&pdev->dev,
"failed requesting tsc irq %d: %d\n",
tsc_irq, err);
return err;
}
err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
dev_name(&pdev->dev), tsc);
if (err) {
dev_err(&pdev->dev,
"failed requesting adc irq %d: %d\n",
adc_irq, err);
return err;
}
err = of_property_read_u32(np, "measure-delay-time",
&tsc->measure_delay_time);
if (err)
tsc->measure_delay_time = 0xffff;
err = of_property_read_u32(np, "pre-charge-time",
&tsc->pre_charge_time);
if (err)
tsc->pre_charge_time = 0xfff;
err = of_property_read_u32(np, "touchscreen-average-samples",
&average_samples);
if (err)
average_samples = 1;
switch (average_samples) {
case 1:
tsc->average_enable = false;
tsc->average_select = 0; /* value unused; initialize anyway */
break;
case 4:
case 8:
case 16:
case 32:
tsc->average_enable = true;
tsc->average_select = ilog2(average_samples) - 2;
break;
default:
dev_err(&pdev->dev,
"touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
average_samples);
return -EINVAL;
}
err = input_register_device(tsc->input);
if (err) {
dev_err(&pdev->dev,
"failed to register input device: %d\n", err);
return err;
}
platform_set_drvdata(pdev, tsc);
return 0;
}
static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
struct input_dev *input_dev = tsc->input;
mutex_lock(&input_dev->mutex);
if (input_dev->users) {
imx6ul_tsc_disable(tsc);
clk_disable_unprepare(tsc->tsc_clk);
clk_disable_unprepare(tsc->adc_clk);
}
mutex_unlock(&input_dev->mutex);
return 0;
}
static int __maybe_unused imx6ul_tsc_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
struct input_dev *input_dev = tsc->input;
int retval = 0;
mutex_lock(&input_dev->mutex);
if (input_dev->users) {
retval = clk_prepare_enable(tsc->adc_clk);
if (retval)
goto out;
retval = clk_prepare_enable(tsc->tsc_clk);
if (retval) {
clk_disable_unprepare(tsc->adc_clk);
goto out;
}
retval = imx6ul_tsc_init(tsc);
}
out:
mutex_unlock(&input_dev->mutex);
return retval;
}
static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
imx6ul_tsc_suspend, imx6ul_tsc_resume);
static const struct of_device_id imx6ul_tsc_match[] = {
{ .compatible = "fsl,imx6ul-tsc", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
static struct platform_driver imx6ul_tsc_driver = {
.driver = {
.name = "imx6ul-tsc",
.of_match_table = imx6ul_tsc_match,
.pm = &imx6ul_tsc_pm_ops,
},
.probe = imx6ul_tsc_probe,
};
module_platform_driver(imx6ul_tsc_driver);
MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
MODULE_LICENSE("GPL v2");