280 lines
6.8 KiB
C
280 lines
6.8 KiB
C
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/*
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* Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2, as
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* published by the Free Software Foundation.
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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_chip_init(struct nspire_keypad *keypad)
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{
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unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
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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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/* 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 interrupts */
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writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
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return 0;
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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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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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error = nspire_keypad_chip_init(keypad);
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if (error) {
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clk_disable_unprepare(keypad->clk);
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return error;
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}
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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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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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dev_err(&pdev->dev, "failed to get keypad irq\n");
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return -EINVAL;
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}
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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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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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platform_set_drvdata(pdev, keypad);
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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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