#include <linux/clk.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#define ST_KEYSCAN_MAXKEYS 16
#define KEYSCAN_CONFIG_OFF 0x0
#define KEYSCAN_CONFIG_ENABLE 0x1
#define KEYSCAN_DEBOUNCE_TIME_OFF 0x4
#define KEYSCAN_MATRIX_STATE_OFF 0x8
#define KEYSCAN_MATRIX_DIM_OFF 0xc
#define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0
#define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2
struct st_keyscan {
void __iomem *base;
int irq;
struct clk *clk;
struct input_dev *input_dev;
unsigned long last_state;
unsigned int n_rows;
unsigned int n_cols;
unsigned int debounce_us;
};
static irqreturn_t keyscan_isr(int irq, void *dev_id)
{
struct st_keyscan *keypad = dev_id;
unsigned short *keycode = keypad->input_dev->keycode;
unsigned long state, change;
int bit_nr;
state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff;
change = keypad->last_state ^ state;
keypad->last_state = state;
for_each_set_bit(bit_nr, &change, BITS_PER_LONG)
input_report_key(keypad->input_dev,
keycode[bit_nr], state & BIT(bit_nr));
input_sync(keypad->input_dev);
return IRQ_HANDLED;
}
static int keyscan_start(struct st_keyscan *keypad)
{
int error;
error = clk_enable(keypad->clk);
if (error)
return error;
writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000),
keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF);
writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) |
((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT),
keypad->base + KEYSCAN_MATRIX_DIM_OFF);
writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF);
return 0;
}
static void keyscan_stop(struct st_keyscan *keypad)
{
writel(0, keypad->base + KEYSCAN_CONFIG_OFF);
clk_disable(keypad->clk);
}
static int keyscan_open(struct input_dev *dev)
{
struct st_keyscan *keypad = input_get_drvdata(dev);
return keyscan_start(keypad);
}
static void keyscan_close(struct input_dev *dev)
{
struct st_keyscan *keypad = input_get_drvdata(dev);
keyscan_stop(keypad);
}
static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data)
{
struct device *dev = keypad_data->input_dev->dev.parent;
struct device_node *np = dev->of_node;
int error;
error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows,
&keypad_data->n_cols);
if (error) {
dev_err(dev, "failed to parse keypad params\n");
return error;
}
of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us);
dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n",
keypad_data->n_rows, keypad_data->n_cols,
keypad_data->debounce_us);
return 0;
}
static int keyscan_probe(struct platform_device *pdev)
{
struct st_keyscan *keypad_data;
struct input_dev *input_dev;
int error;
if (!pdev->dev.of_node) {
dev_err(&pdev->dev, "no DT data present\n");
return -EINVAL;
}
keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data),
GFP_KERNEL);
if (!keypad_data)
return -ENOMEM;
input_dev = devm_input_allocate_device(&pdev->dev);
if (!input_dev) {
dev_err(&pdev->dev, "failed to allocate the input device\n");
return -ENOMEM;
}
input_dev->name = pdev->name;
input_dev->phys = "keyscan-keys/input0";
input_dev->dev.parent = &pdev->dev;
input_dev->open = keyscan_open;
input_dev->close = keyscan_close;
input_dev->id.bustype = BUS_HOST;
keypad_data->input_dev = input_dev;
error = keypad_matrix_key_parse_dt(keypad_data);
if (error)
return error;
error = matrix_keypad_build_keymap(NULL, NULL,
keypad_data->n_rows,
keypad_data->n_cols,
NULL, input_dev);
if (error) {
dev_err(&pdev->dev, "failed to build keymap\n");
return error;
}
input_set_drvdata(input_dev, keypad_data);
keypad_data->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
if (IS_ERR(keypad_data->base))
return PTR_ERR(keypad_data->base);
keypad_data->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(keypad_data->clk)) {
dev_err(&pdev->dev, "cannot get clock\n");
return PTR_ERR(keypad_data->clk);
}
error = clk_enable(keypad_data->clk);
if (error) {
dev_err(&pdev->dev, "failed to enable clock\n");
return error;
}
keyscan_stop(keypad_data);
keypad_data->irq = platform_get_irq(pdev, 0);
if (keypad_data->irq < 0)
return -EINVAL;
error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0,
pdev->name, keypad_data);
if (error) {
dev_err(&pdev->dev, "failed to request IRQ\n");
return error;
}
error = input_register_device(input_dev);
if (error) {
dev_err(&pdev->dev, "failed to register input device\n");
return error;
}
platform_set_drvdata(pdev, keypad_data);
device_set_wakeup_capable(&pdev->dev, 1);
return 0;
}
static int keyscan_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct st_keyscan *keypad = platform_get_drvdata(pdev);
struct input_dev *input = keypad->input_dev;
guard(mutex)(&input->mutex);
if (device_may_wakeup(dev))
enable_irq_wake(keypad->irq);
else if (input_device_enabled(input))
keyscan_stop(keypad);
return 0;
}
static int keyscan_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct st_keyscan *keypad = platform_get_drvdata(pdev);
struct input_dev *input = keypad->input_dev;
int error;
guard(mutex)(&input->mutex);
if (device_may_wakeup(dev)) {
disable_irq_wake(keypad->irq);
} else if (input_device_enabled(input)) {
error = keyscan_start(keypad);
if (error)
return error;
}
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops,
keyscan_suspend, keyscan_resume);
static const struct of_device_id keyscan_of_match[] = {
{ .compatible = "st,sti-keyscan" },
{ },
};
MODULE_DEVICE_TABLE(of, keyscan_of_match);
static struct platform_driver keyscan_device_driver = {
.probe = keyscan_probe,
.driver = {
.name = "st-keyscan",
.pm = pm_sleep_ptr(&keyscan_dev_pm_ops),
.of_match_table = keyscan_of_match,
}
};
module_platform_driver(keyscan_device_driver);
MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>");
MODULE_DESCRIPTION("STMicroelectronics keyscan device driver");
MODULE_LICENSE("GPL");
