--- /dev/null
+/*
+ * STMicroelectronics Key Scanning driver
+ *
+ * Copyright (c) 2014 STMicroelectonics Ltd.
+ * Author: Stuart Menefy <stuart.menefy@st.com>
+ *
+ * Based on sh_keysc.c, copyright 2008 Magnus Damm
+ *
+ * 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/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/input/matrix_keypad.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_of_params(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;
+ struct resource *res;
+ 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;
+
+ 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->input_dev = input_dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ keypad_data->base = devm_ioremap_resource(&pdev->dev, res);
+ 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) {
+ dev_err(&pdev->dev, "no IRQ specified\n");
+ 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;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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;
+
+ mutex_lock(&input->mutex);
+
+ if (device_may_wakeup(dev))
+ enable_irq_wake(keypad->irq);
+ else if (input->users)
+ keyscan_stop(keypad);
+
+ mutex_unlock(&input->mutex);
+ 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 retval = 0;
+
+ mutex_lock(&input->mutex);
+
+ if (device_may_wakeup(dev))
+ disable_irq_wake(keypad->irq);
+ else if (input->users)
+ retval = keyscan_start(keypad);
+
+ mutex_unlock(&input->mutex);
+ return retval;
+}
+#endif
+
+static 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 = &keyscan_dev_pm_ops,
+ .of_match_table = of_match_ptr(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");
Code Review / kvmfornfv.git / blobdiff