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