--- /dev/null
+TI-NSPIRE Keypad
+
+Required properties:
+- compatible: Compatible property value should be "ti,nspire-keypad".
+
+- reg: Physical base address of the peripheral and length of memory mapped
+ region.
+
+- interrupts: The interrupt number for the peripheral.
+
+- scan-interval: How often to scan in us. Based on a APB speed of 33MHz, the
+ maximum and minimum delay time is ~2000us and ~500us respectively
+
+- row-delay: How long to wait before scanning each row.
+
+- clocks: The clock this peripheral is attached to.
+
+- linux,keymap: The keymap to use
+ (see Documentation/devicetree/bindings/input/matrix-keymap.txt)
+
+Optional properties:
+- active-low: Specify that the keypad is active low (i.e. logical low signifies
+ a key press).
+
+Example:
+
+input {
+ compatible = "ti,nspire-keypad";
+ reg = <0x900E0000 0x1000>;
+ interrupts = <16>;
+
+ scan-interval = <1000>;
+ row-delay = <200>;
+
+ clocks = <&apb_pclk>;
+
+ linux,keymap = <
+ 0x0000001c 0x0001001c 0x00040039
+ 0x0005002c 0x00060015 0x0007000b
+ 0x0008000f 0x0100002d 0x01010011
+ 0x0102002f 0x01030004 0x01040016
+ 0x01050014 0x0106001f 0x01070002
+ 0x010a006a 0x02000013 0x02010010
+ 0x02020019 0x02030007 0x02040018
+ 0x02050031 0x02060032 0x02070005
+ 0x02080028 0x0209006c 0x03000026
+ 0x03010025 0x03020024 0x0303000a
+ 0x03040017 0x03050023 0x03060022
+ 0x03070008 0x03080035 0x03090069
+ 0x04000021 0x04010012 0x04020020
+ 0x0404002e 0x04050030 0x0406001e
+ 0x0407000d 0x04080037 0x04090067
+ 0x05010038 0x0502000c 0x0503001b
+ 0x05040034 0x0505001a 0x05060006
+ 0x05080027 0x0509000e 0x050a006f
+ 0x0600002b 0x0602004e 0x06030068
+ 0x06040003 0x0605006d 0x06060009
+ 0x06070001 0x0609000f 0x0708002a
+ 0x0709001d 0x070a0033 >;
+};
--- /dev/null
+/*
+ * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
+ *
+ * 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/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_chip_init(struct nspire_keypad *keypad)
+{
+ unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
+
+ 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 + 0xc);
+
+ /* Disable GPIO interrupts to prevent hanging on touchpad */
+ /* Possibly used to detect touchpad events */
+ writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
+ /* Acknowledge existing interrupts */
+ writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
+
+ return 0;
+}
+
+static int nspire_keypad_open(struct input_dev *input)
+{
+ struct nspire_keypad *keypad = input_get_drvdata(input);
+ int error;
+
+ error = clk_prepare_enable(keypad->clk);
+ if (error)
+ return error;
+
+ error = nspire_keypad_chip_init(keypad);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static void nspire_keypad_close(struct input_dev *input)
+{
+ struct nspire_keypad *keypad = input_get_drvdata(input);
+
+ 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) {
+ dev_err(&pdev->dev, "failed to get keypad irq\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "missing platform resources\n");
+ 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);
+ }
+
+ keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(keypad->reg_base)) {
+ dev_err(&pdev->dev, "failed to remap I/O memory\n");
+ 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;
+ }
+
+ 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;
+ }
+
+ platform_set_drvdata(pdev, keypad);
+
+ 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",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(nspire_keypad_dt_match),
+ },
+ .probe = nspire_keypad_probe,
+};
+
+module_platform_driver(nspire_keypad_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff