diff options
Diffstat (limited to 'drivers/input/keyboard/st-keyscan.c')
| -rw-r--r-- | drivers/input/keyboard/st-keyscan.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/drivers/input/keyboard/st-keyscan.c b/drivers/input/keyboard/st-keyscan.c new file mode 100644 index 000000000..a62bb8fff --- /dev/null +++ b/drivers/input/keyboard/st-keyscan.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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 + */ + +#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; + 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; + + 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); + + 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) + 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_device_enabled(input)) + 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_device_enabled(input)) + 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"); |