Input: add TI-Nspire keypad support
authorDaniel Tang <dt.tangr@gmail.com>
Thu, 30 May 2013 20:16:10 +0000 (13:16 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Tue, 4 Jun 2013 16:17:25 +0000 (09:17 -0700)
This is a driver for the keypads found on the TI-Nspire series calculators.

Signed-off-by: Daniel Tang <dt.tangr@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Documentation/devicetree/bindings/input/ti,nspire-keypad.txt [new file with mode: 0644]
drivers/input/keyboard/Kconfig
drivers/input/keyboard/Makefile
drivers/input/keyboard/nspire-keypad.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/input/ti,nspire-keypad.txt b/Documentation/devicetree/bindings/input/ti,nspire-keypad.txt
new file mode 100644 (file)
index 0000000..513d94d
--- /dev/null
@@ -0,0 +1,60 @@
+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      >;
+};
index ac050066700086d2477d1e56f459bc6bc6f313d2..37c366623fc099f5cbc1109bbcbd23404245d0e9 100644 (file)
@@ -418,6 +418,16 @@ config KEYBOARD_NOMADIK
          To compile this driver as a module, choose M here: the
          module will be called nmk-ske-keypad.
 
+config KEYBOARD_NSPIRE
+       tristate "TI-NSPIRE built-in keyboard"
+       depends on ARCH_NSPIRE && OF
+       select INPUT_MATRIXKMAP
+       help
+         Say Y here if you want to use the built-in keypad on TI-NSPIRE.
+
+         To compile this driver as a module, choose M here: the
+         module will be called nspire-keypad.
+
 config KEYBOARD_TEGRA
        tristate "NVIDIA Tegra internal matrix keyboard controller support"
        depends on ARCH_TEGRA && OF
index 49b16453d00ef84184d2beddbee95d7c3a3e33ea..89d997b05452bcc7e9a9d76024c9a21932e42ccd 100644 (file)
@@ -35,6 +35,7 @@ obj-$(CONFIG_KEYBOARD_MCS)            += mcs_touchkey.o
 obj-$(CONFIG_KEYBOARD_MPR121)          += mpr121_touchkey.o
 obj-$(CONFIG_KEYBOARD_NEWTON)          += newtonkbd.o
 obj-$(CONFIG_KEYBOARD_NOMADIK)         += nomadik-ske-keypad.o
+obj-$(CONFIG_KEYBOARD_NSPIRE)          += nspire-keypad.o
 obj-$(CONFIG_KEYBOARD_OMAP)            += omap-keypad.o
 obj-$(CONFIG_KEYBOARD_OMAP4)           += omap4-keypad.o
 obj-$(CONFIG_KEYBOARD_OPENCORES)       += opencores-kbd.o
diff --git a/drivers/input/keyboard/nspire-keypad.c b/drivers/input/keyboard/nspire-keypad.c
new file mode 100644 (file)
index 0000000..1b0d04c
--- /dev/null
@@ -0,0 +1,285 @@
+/*
+ *  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");