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Diffstat (limited to '')
| -rw-r--r-- | drivers/input/keyboard/nspire-keypad.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/drivers/input/keyboard/nspire-keypad.c b/drivers/input/keyboard/nspire-keypad.c new file mode 100644 index 000000000..e9fa1423f --- /dev/null +++ b/drivers/input/keyboard/nspire-keypad.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au> + */ + +#include <linux/input/matrix_keypad.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/input.h> +#include <linux/slab.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/of.h> + +#define KEYPAD_SCAN_MODE 0x00 +#define KEYPAD_CNTL 0x04 +#define KEYPAD_INT 0x08 +#define KEYPAD_INTMSK 0x0C + +#define KEYPAD_DATA 0x10 +#define KEYPAD_GPIO 0x30 + +#define KEYPAD_UNKNOWN_INT 0x40 +#define KEYPAD_UNKNOWN_INT_STS 0x44 + +#define KEYPAD_BITMASK_COLS 11 +#define KEYPAD_BITMASK_ROWS 8 + +struct nspire_keypad { + void __iomem *reg_base; + u32 int_mask; + + struct input_dev *input; + struct clk *clk; + + struct matrix_keymap_data *keymap; + int row_shift; + + /* Maximum delay estimated assuming 33MHz APB */ + u32 scan_interval; /* In microseconds (~2000us max) */ + u32 row_delay; /* In microseconds (~500us max) */ + + u16 state[KEYPAD_BITMASK_ROWS]; + + bool active_low; +}; + +static irqreturn_t nspire_keypad_irq(int irq, void *dev_id) +{ + struct nspire_keypad *keypad = dev_id; + struct input_dev *input = keypad->input; + unsigned short *keymap = input->keycode; + unsigned int code; + int row, col; + u32 int_sts; + u16 state[8]; + u16 bits, changed; + + int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask; + if (!int_sts) + return IRQ_NONE; + + memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state)); + + for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) { + bits = state[row]; + if (keypad->active_low) + bits = ~bits; + + changed = bits ^ keypad->state[row]; + if (!changed) + continue; + + keypad->state[row] = bits; + + for (col = 0; col < KEYPAD_BITMASK_COLS; col++) { + if (!(changed & (1U << col))) + continue; + + code = MATRIX_SCAN_CODE(row, col, keypad->row_shift); + input_event(input, EV_MSC, MSC_SCAN, code); + input_report_key(input, keymap[code], + bits & (1U << col)); + } + } + + input_sync(input); + + writel(0x3, keypad->reg_base + KEYPAD_INT); + + return IRQ_HANDLED; +} + +static int nspire_keypad_open(struct input_dev *input) +{ + struct nspire_keypad *keypad = input_get_drvdata(input); + unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles; + int error; + + error = clk_prepare_enable(keypad->clk); + if (error) + return error; + + cycles_per_us = (clk_get_rate(keypad->clk) / 1000000); + if (cycles_per_us == 0) + cycles_per_us = 1; + + delay_cycles = cycles_per_us * keypad->scan_interval; + WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */ + delay_cycles &= 0xffff; + + row_delay_cycles = cycles_per_us * keypad->row_delay; + WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */ + row_delay_cycles &= 0x3fff; + + val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */ + val |= row_delay_cycles << 2; /* Delay between scanning each row */ + val |= delay_cycles << 16; /* Delay between scans */ + writel(val, keypad->reg_base + KEYPAD_SCAN_MODE); + + val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8; + writel(val, keypad->reg_base + KEYPAD_CNTL); + + /* Enable interrupts */ + keypad->int_mask = 1 << 1; + writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK); + + return 0; +} + +static void nspire_keypad_close(struct input_dev *input) +{ + struct nspire_keypad *keypad = input_get_drvdata(input); + + /* Disable interrupts */ + writel(0, keypad->reg_base + KEYPAD_INTMSK); + /* Acknowledge existing interrupts */ + writel(~0, keypad->reg_base + KEYPAD_INT); + + clk_disable_unprepare(keypad->clk); +} + +static int nspire_keypad_probe(struct platform_device *pdev) +{ + const struct device_node *of_node = pdev->dev.of_node; + struct nspire_keypad *keypad; + struct input_dev *input; + struct resource *res; + int irq; + int error; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return -EINVAL; + + keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad), + GFP_KERNEL); + if (!keypad) { + dev_err(&pdev->dev, "failed to allocate keypad memory\n"); + return -ENOMEM; + } + + keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS); + + error = of_property_read_u32(of_node, "scan-interval", + &keypad->scan_interval); + if (error) { + dev_err(&pdev->dev, "failed to get scan-interval\n"); + return error; + } + + error = of_property_read_u32(of_node, "row-delay", + &keypad->row_delay); + if (error) { + dev_err(&pdev->dev, "failed to get row-delay\n"); + return error; + } + + keypad->active_low = of_property_read_bool(of_node, "active-low"); + + keypad->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(keypad->clk)) { + dev_err(&pdev->dev, "unable to get clock\n"); + return PTR_ERR(keypad->clk); + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + keypad->reg_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(keypad->reg_base)) + return PTR_ERR(keypad->reg_base); + + keypad->input = input = devm_input_allocate_device(&pdev->dev); + if (!input) { + dev_err(&pdev->dev, "failed to allocate input device\n"); + return -ENOMEM; + } + + error = clk_prepare_enable(keypad->clk); + if (error) { + dev_err(&pdev->dev, "failed to enable clock\n"); + return error; + } + + /* Disable interrupts */ + writel(0, keypad->reg_base + KEYPAD_INTMSK); + /* Acknowledge existing interrupts */ + writel(~0, keypad->reg_base + KEYPAD_INT); + + /* Disable GPIO interrupts to prevent hanging on touchpad */ + /* Possibly used to detect touchpad events */ + writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT); + /* Acknowledge existing GPIO interrupts */ + writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS); + + clk_disable_unprepare(keypad->clk); + + input_set_drvdata(input, keypad); + + input->id.bustype = BUS_HOST; + input->name = "nspire-keypad"; + input->open = nspire_keypad_open; + input->close = nspire_keypad_close; + + __set_bit(EV_KEY, input->evbit); + __set_bit(EV_REP, input->evbit); + input_set_capability(input, EV_MSC, MSC_SCAN); + + error = matrix_keypad_build_keymap(NULL, NULL, + KEYPAD_BITMASK_ROWS, + KEYPAD_BITMASK_COLS, + NULL, input); + if (error) { + dev_err(&pdev->dev, "building keymap failed\n"); + return error; + } + + error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0, + "nspire_keypad", keypad); + if (error) { + dev_err(&pdev->dev, "allocate irq %d failed\n", irq); + return error; + } + + error = input_register_device(input); + if (error) { + dev_err(&pdev->dev, + "unable to register input device: %d\n", error); + return error; + } + + dev_dbg(&pdev->dev, + "TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n", + res, keypad->row_delay, keypad->scan_interval, + keypad->active_low ? ", active_low" : ""); + + return 0; +} + +static const struct of_device_id nspire_keypad_dt_match[] = { + { .compatible = "ti,nspire-keypad" }, + { }, +}; +MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match); + +static struct platform_driver nspire_keypad_driver = { + .driver = { + .name = "nspire-keypad", + .of_match_table = nspire_keypad_dt_match, + }, + .probe = nspire_keypad_probe, +}; + +module_platform_driver(nspire_keypad_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver"); |