Input: add twl4030_keypad driver

Add a driver for the keypad controller on TWL4030 family chips.
These support up to an 8x8 key matrix.  The TWL4030 multifunction
chips are mostly used on OMAP3 (or OMAP 2430) based boards.

[dtor@mail.ru: switch to matrix-keypad framework, fix changing
keymap from userspace]
Reviewed-by: Trilok Soni <soni.trilok@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 480 insertions, 0 deletions

diff --git a/drivers/input/keyboard/twl4030_keypad.c b/drivers/input/keyboard/twl4030_keypad.c
new file mode 100644
index 000000000000..9a2977c21696
--- /dev/null
+++ b/drivers/input/keyboard/twl4030_keypad.c
@@ -0,0 +1,480 @@
+/*
+ * twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips
+ *
+ * Copyright (C) 2007 Texas Instruments, Inc.
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * Code re-written for 2430SDP by:
+ * Syed Mohammed Khasim <x0khasim@ti.com>
+ *
+ * Initial Code:
+ * Manjunatha G K <manjugk@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/i2c/twl4030.h>
+
+
+/*
+ * The TWL4030 family chips include a keypad controller that supports
+ * up to an 8x8 switch matrix.  The controller can issue system wakeup
+ * events, since it uses only the always-on 32KiHz oscillator, and has
+ * an internal state machine that decodes pressed keys, including
+ * multi-key combinations.
+ *
+ * This driver lets boards define what keycodes they wish to report for
+ * which scancodes, as part of the "struct twl4030_keypad_data" used in
+ * the probe() routine.
+ *
+ * See the TPS65950 documentation; that's the general availability
+ * version of the TWL5030 second generation part.
+ */
+#define TWL4030_MAX_ROWS	8	/* TWL4030 hard limit */
+#define TWL4030_MAX_COLS	8
+#define TWL4030_ROW_SHIFT	3
+#define TWL4030_KEYMAP_SIZE	(TWL4030_MAX_ROWS * TWL4030_MAX_COLS)
+
+struct twl4030_keypad {
+	unsigned short	keymap[TWL4030_KEYMAP_SIZE];
+	u16		kp_state[TWL4030_MAX_ROWS];
+	unsigned	n_rows;
+	unsigned	n_cols;
+	unsigned	irq;
+
+	struct device *dbg_dev;
+	struct input_dev *input;
+};
+
+/*----------------------------------------------------------------------*/
+
+/* arbitrary prescaler value 0..7 */
+#define PTV_PRESCALER			4
+
+/* Register Offsets */
+#define KEYP_CTRL			0x00
+#define KEYP_DEB			0x01
+#define KEYP_LONG_KEY			0x02
+#define KEYP_LK_PTV			0x03
+#define KEYP_TIMEOUT_L			0x04
+#define KEYP_TIMEOUT_H			0x05
+#define KEYP_KBC			0x06
+#define KEYP_KBR			0x07
+#define KEYP_SMS			0x08
+#define KEYP_FULL_CODE_7_0		0x09	/* row 0 column status */
+#define KEYP_FULL_CODE_15_8		0x0a	/* ... row 1 ... */
+#define KEYP_FULL_CODE_23_16		0x0b
+#define KEYP_FULL_CODE_31_24		0x0c
+#define KEYP_FULL_CODE_39_32		0x0d
+#define KEYP_FULL_CODE_47_40		0x0e
+#define KEYP_FULL_CODE_55_48		0x0f
+#define KEYP_FULL_CODE_63_56		0x10
+#define KEYP_ISR1			0x11
+#define KEYP_IMR1			0x12
+#define KEYP_ISR2			0x13
+#define KEYP_IMR2			0x14
+#define KEYP_SIR			0x15
+#define KEYP_EDR			0x16	/* edge triggers */
+#define KEYP_SIH_CTRL			0x17
+
+/* KEYP_CTRL_REG Fields */
+#define KEYP_CTRL_SOFT_NRST		BIT(0)
+#define KEYP_CTRL_SOFTMODEN		BIT(1)
+#define KEYP_CTRL_LK_EN			BIT(2)
+#define KEYP_CTRL_TOE_EN		BIT(3)
+#define KEYP_CTRL_TOLE_EN		BIT(4)
+#define KEYP_CTRL_RP_EN			BIT(5)
+#define KEYP_CTRL_KBD_ON		BIT(6)
+
+/* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
+#define KEYP_PERIOD_US(t, prescale)	((t) / (31 << (prescale + 1)) - 1)
+
+/* KEYP_LK_PTV_REG Fields */
+#define KEYP_LK_PTV_PTV_SHIFT		5
+
+/* KEYP_{IMR,ISR,SIR} Fields */
+#define KEYP_IMR1_MIS			BIT(3)
+#define KEYP_IMR1_TO			BIT(2)
+#define KEYP_IMR1_LK			BIT(1)
+#define KEYP_IMR1_KP			BIT(0)
+
+/* KEYP_EDR Fields */
+#define KEYP_EDR_KP_FALLING		0x01
+#define KEYP_EDR_KP_RISING		0x02
+#define KEYP_EDR_KP_BOTH		0x03
+#define KEYP_EDR_LK_FALLING		0x04
+#define KEYP_EDR_LK_RISING		0x08
+#define KEYP_EDR_TO_FALLING		0x10
+#define KEYP_EDR_TO_RISING		0x20
+#define KEYP_EDR_MIS_FALLING		0x40
+#define KEYP_EDR_MIS_RISING		0x80
+
+
+/*----------------------------------------------------------------------*/
+
+static int twl4030_kpread(struct twl4030_keypad *kp,
+		u8 *data, u32 reg, u8 num_bytes)
+{
+	int ret = twl4030_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
+
+	if (ret < 0)
+		dev_warn(kp->dbg_dev,
+			"Couldn't read TWL4030: %X - ret %d[%x]\n",
+			 reg, ret, ret);
+
+	return ret;
+}
+
+static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
+{
+	int ret = twl4030_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
+
+	if (ret < 0)
+		dev_warn(kp->dbg_dev,
+			"Could not write TWL4030: %X - ret %d[%x]\n",
+			 reg, ret, ret);
+
+	return ret;
+}
+
+static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
+{
+	/* If all bits in a row are active for all coloumns then
+	 * we have that row line connected to gnd. Mark this
+	 * key on as if it was on matrix position n_cols (ie
+	 * one higher than the size of the matrix).
+	 */
+	if (col == 0xFF)
+		return 1 << kp->n_cols;
+	else
+		return col & ((1 << kp->n_cols) - 1);
+}
+
+static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
+{
+	u8 new_state[TWL4030_MAX_ROWS];
+	int row;
+	int ret = twl4030_kpread(kp, new_state,
+				 KEYP_FULL_CODE_7_0, kp->n_rows);
+	if (ret >= 0)
+		for (row = 0; row < kp->n_rows; row++)
+			state[row] = twl4030_col_xlate(kp, new_state[row]);
+
+	return ret;
+}
+
+static int twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
+{
+	int i;
+	u16 check = 0;
+
+	for (i = 0; i < kp->n_rows; i++) {
+		u16 col = key_state[i];
+
+		if ((col & check) && hweight16(col) > 1)
+			return 1;
+
+		check |= col;
+	}
+
+	return 0;
+}
+
+static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
+{
+	struct input_dev *input = kp->input;
+	u16 new_state[TWL4030_MAX_ROWS];
+	int col, row;
+
+	if (release_all)
+		memset(new_state, 0, sizeof(new_state));
+	else {
+		/* check for any changes */
+		int ret = twl4030_read_kp_matrix_state(kp, new_state);
+
+		if (ret < 0)	/* panic ... */
+			return;
+
+		if (twl4030_is_in_ghost_state(kp, new_state))
+			return;
+	}
+
+	/* check for changes and print those */
+	for (row = 0; row < kp->n_rows; row++) {
+		int changed = new_state[row] ^ kp->kp_state[row];
+
+		if (!changed)
+			continue;
+
+		for (col = 0; col < kp->n_cols; col++) {
+			int code;
+
+			if (!(changed & (1 << col)))
+				continue;
+
+			dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
+				(new_state[row] & (1 << col)) ?
+				"press" : "release");
+
+			code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
+			input_event(input, EV_MSC, MSC_SCAN, code);
+			input_report_key(input, kp->keymap[code],
+					 new_state[row] & (1 << col));
+		}
+		kp->kp_state[row] = new_state[row];
+	}
+	input_sync(input);
+}
+
+/*
+ * Keypad interrupt handler
+ */
+static irqreturn_t do_kp_irq(int irq, void *_kp)
+{
+	struct twl4030_keypad *kp = _kp;
+	u8 reg;
+	int ret;
+
+#ifdef CONFIG_LOCKDEP
+	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+	 * we don't want and can't tolerate.  Although it might be
+	 * friendlier not to borrow this thread context...
+	 */
+	local_irq_enable();
+#endif
+
+	/* Read & Clear TWL4030 pending interrupt */
+	ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
+
+	/* Release all keys if I2C has gone bad or
+	 * the KEYP has gone to idle state */
+	if (ret >= 0 && (reg & KEYP_IMR1_KP))
+		twl4030_kp_scan(kp, false);
+	else
+		twl4030_kp_scan(kp, true);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
+{
+	u8 reg;
+	int i;
+
+	/* Enable controller, with hardware decoding but not autorepeat */
+	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
+		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
+	if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
+		return -EIO;
+
+	/* NOTE:  we could use sih_setup() here to package keypad
+	 * event sources as four different IRQs ... but we don't.
+	 */
+
+	/* Enable TO rising and KP rising and falling edge detection */
+	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
+	if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
+		return -EIO;
+
+	/* Set PTV prescaler Field */
+	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
+	if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
+		return -EIO;
+
+	/* Set key debounce time to 20 ms */
+	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
+	if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
+		return -EIO;
+
+	/* Set timeout period to 100 ms */
+	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
+	if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
+		return -EIO;
+
+	if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
+		return -EIO;
+
+	/*
+	 * Enable Clear-on-Read; disable remembering events that fire
+	 * after the IRQ but before our handler acks (reads) them,
+	 */
+	reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
+	if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
+		return -EIO;
+
+	/* initialize key state; irqs update it from here on */
+	if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
+		return -EIO;
+
+	return 0;
+}
+
+/*
+ * Registers keypad device with input subsystem
+ * and configures TWL4030 keypad registers
+ */
+static int __devinit twl4030_kp_probe(struct platform_device *pdev)
+{
+	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
+	const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
+	struct twl4030_keypad *kp;
+	struct input_dev *input;
+	u8 reg;
+	int error;
+
+	if (!pdata || !pdata->rows || !pdata->cols ||
+	    pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
+		dev_err(&pdev->dev, "Invalid platform_data\n");
+		return -EINVAL;
+	}
+
+	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
+	input = input_allocate_device();
+	if (!kp || !input) {
+		error = -ENOMEM;
+		goto err1;
+	}
+
+	/* Get the debug Device */
+	kp->dbg_dev = &pdev->dev;
+	kp->input = input;
+
+	kp->n_rows = pdata->rows;
+	kp->n_cols = pdata->cols;
+	kp->irq = platform_get_irq(pdev, 0);
+
+	/* setup input device */
+	__set_bit(EV_KEY, input->evbit);
+
+	/* Enable auto repeat feature of Linux input subsystem */
+	if (pdata->rep)
+		__set_bit(EV_REP, input->evbit);
+
+	input_set_capability(input, EV_MSC, MSC_SCAN);
+
+	input->name		= "TWL4030 Keypad";
+	input->phys		= "twl4030_keypad/input0";
+	input->dev.parent	= &pdev->dev;
+
+	input->id.bustype	= BUS_HOST;
+	input->id.vendor	= 0x0001;
+	input->id.product	= 0x0001;
+	input->id.version	= 0x0003;
+
+	input->keycode		= kp->keymap;
+	input->keycodesize	= sizeof(kp->keymap[0]);
+	input->keycodemax	= ARRAY_SIZE(kp->keymap);
+
+	matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
+				   input->keycode, input->keybit);
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(kp->dbg_dev,
+			"Unable to register twl4030 keypad device\n");
+		goto err1;
+	}
+
+	error = twl4030_kp_program(kp);
+	if (error)
+		goto err2;
+
+	/*
+	 * This ISR will always execute in kernel thread context because of
+	 * the need to access the TWL4030 over the I2C bus.
+	 *
+	 * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
+	 */
+	error = request_irq(kp->irq, do_kp_irq, 0, pdev->name, kp);
+	if (error) {
+		dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
+			kp->irq);
+		goto err3;
+	}
+
+	/* Enable KP and TO interrupts now. */
+	reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
+	if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
+		error = -EIO;
+		goto err4;
+	}
+
+	platform_set_drvdata(pdev, kp);
+	return 0;
+
+err4:
+	/* mask all events - we don't care about the result */
+	(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
+err3:
+	free_irq(kp->irq, NULL);
+err2:
+	input_unregister_device(input);
+	input = NULL;
+err1:
+	input_free_device(input);
+	kfree(kp);
+	return error;
+}
+
+static int __devexit twl4030_kp_remove(struct platform_device *pdev)
+{
+	struct twl4030_keypad *kp = platform_get_drvdata(pdev);
+
+	free_irq(kp->irq, kp);
+	input_unregister_device(kp->input);
+	platform_set_drvdata(pdev, NULL);
+	kfree(kp);
+
+	return 0;
+}
+
+/*
+ * NOTE: twl4030 are multi-function devices connected via I2C.
+ * So this device is a child of an I2C parent, thus it needs to
+ * support unplug/replug (which most platform devices don't).
+ */
+
+static struct platform_driver twl4030_kp_driver = {
+	.probe		= twl4030_kp_probe,
+	.remove		= __devexit_p(twl4030_kp_remove),
+	.driver		= {
+		.name	= "twl4030_keypad",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init twl4030_kp_init(void)
+{
+	return platform_driver_register(&twl4030_kp_driver);
+}
+module_init(twl4030_kp_init);
+
+static void __exit twl4030_kp_exit(void)
+{
+	platform_driver_unregister(&twl4030_kp_driver);
+}
+module_exit(twl4030_kp_exit);
+
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("TWL4030 Keypad Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:twl4030_keypad");
+