[patch/rfc 2.6.28-rc2] input: twl4030_keypad driver

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From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>

Driver for the twl4030 family keypad controller.  This controller
supports a key matrix of up to 8 rows by 8 columns.  Board init
code passes a description of the key matrix to the driver.

Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
This is what's in the current OMAP tree, with two changes:
(a) includes a pending patch to remove OMAP-isms; (b) rename
to remove another OMAP-ism.

 drivers/input/keyboard/Kconfig          |   11 
 drivers/input/keyboard/Makefile         |    1 
 drivers/input/keyboard/twl4030_keypad.c |  489 ++++++++++++++++++++++++++++++
 include/linux/i2c/twl4030.h             |    9 
 4 files changed, 509 insertions(+), 1 deletion(-)

--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -259,6 +259,17 @@ config KEYBOARD_OMAP
 	  To compile this driver as a module, choose M here: the
 	  module will be called omap-keypad.
 
+config KEYBOARD_TWL4030
+	tristate "TI TWL4030/TWL5030/TPS659x0 keypad support"
+	depends on TWL4030_CORE
+	help
+	  Say Y here if your board use the keypad controller on
+	  TWL4030 family chips.  It's safe to say enable this
+	  even on boards that don't use the keypad controller.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called twl4030_keypad.
+
 config KEYBOARD_PXA27x
 	tristate "PXA27x/PXA3xx keypad support"
 	depends on PXA27x || PXA3xx
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -28,3 +28,4 @@ obj-$(CONFIG_KEYBOARD_HP7XX)		+= jornada
 obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o
 obj-$(CONFIG_KEYBOARD_BFIN)		+= bf54x-keys.o
 obj-$(CONFIG_KEYBOARD_SH_KEYSC)		+= sh_keysc.o
+obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
--- /dev/null
+++ b/drivers/input/keyboard/twl4030_keypad.c
@@ -0,0 +1,489 @@
+/*
+ * twl4030_keypad.c
+ *
+ * Copyright (C) 2007 Texas Instruments, Inc.
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * Code re-written for 2430SDP by:
+ * Syed Mohammed Khasim <x0khasim@xxxxxx>
+ *
+ * Initial Code:
+ * Manjunatha G K <manjugk@xxxxxx>
+ *
+ * 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 MAX_ROWS		8	/* TWL4030 hard limit */
+
+struct twl4030_keypad {
+	int		*keymap;
+	unsigned int	keymapsize;
+	u16		kp_state[MAX_ROWS];
+	int		n_rows;
+	int		n_cols;
+	int		irq;
+
+	struct device	*dbg_dev;
+	struct input_dev *input;
+};
+
+#define ROWCOL_MASK	KEY(0xf, 0xf, 0)
+#define KEYNUM_MASK	(~PERSISTENT_KEY(0xf, 0xf))
+
+/*----------------------------------------------------------------------*/
+
+/* 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;
+
+	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;
+	}
+	return ret;
+}
+
+static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
+{
+	int ret;
+
+	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;
+	}
+	return ret;
+}
+
+static int twl4030_find_key(struct twl4030_keypad *kp, int col, int row)
+{
+	int i, rc;
+
+	rc = KEY(col, row, 0);
+	for (i = 0; i < kp->keymapsize; i++)
+		if ((kp->keymap[i] & ROWCOL_MASK) == rc)
+			return kp->keymap[i] & (KEYNUM_MASK | KEY_PERSISTENT);
+
+	return -EINVAL;
+}
+
+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[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, int release_all)
+{
+	u16 new_state[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 key;
+
+			if (!(changed & (1 << col)))
+				continue;
+
+			dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
+				(new_state[row] & (1 << col)) ?
+				"press" : "release");
+
+			key = twl4030_find_key(kp, col, row);
+			if (key < 0)
+				dev_warn(kp->dbg_dev,
+					"Spurious key event %d-%d\n",
+					 col, row);
+			else if (key & KEY_PERSISTENT)
+				continue;
+			else
+				input_report_key(kp->input, key,
+						 new_state[row] & (1 << col));
+		}
+		kp->kp_state[row] = new_state[row];
+	}
+}
+
+/*
+ * 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, 0);
+	else
+		twl4030_kp_scan(kp, 1);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Registers keypad device with input subsystem
+ * and configures TWL4030 keypad registers
+ */
+static int __devinit twl4030_kp_probe(struct platform_device *pdev)
+{
+	u8 reg;
+	int i;
+	int ret = 0;
+	struct twl4030_keypad *kp;
+	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
+
+	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
+	if (!kp)
+		return -ENOMEM;
+
+	if (!pdata->rows || !pdata->cols || !pdata->keymap) {
+		dev_err(&pdev->dev, "No rows, cols or keymap from pdata\n");
+		kfree(kp);
+		return -EINVAL;
+	}
+
+	/* ASSERT:  cols <= 8, rows <= 8 */
+
+	dev_set_drvdata(&pdev->dev, kp);
+
+	/* Get the debug Device */
+	kp->dbg_dev = &pdev->dev;
+
+	kp->input = input_allocate_device();
+	if (!kp->input) {
+		kfree(kp);
+		return -ENOMEM;
+	}
+
+	kp->keymap = pdata->keymap;
+	kp->keymapsize = pdata->keymapsize;
+	kp->n_rows = pdata->rows;
+	kp->n_cols = pdata->cols;
+	kp->irq = platform_get_irq(pdev, 0);
+
+	/* setup input device */
+	set_bit(EV_KEY, kp->input->evbit);
+
+	/* Enable auto repeat feature of Linux input subsystem */
+	if (pdata->rep)
+		set_bit(EV_REP, kp->input->evbit);
+
+	for (i = 0; i < kp->keymapsize; i++)
+		set_bit(kp->keymap[i] & KEYNUM_MASK,
+				kp->input->keybit);
+
+	kp->input->name	= "TWL4030 Keypad";
+	kp->input->phys	= "twl4030_keypad/input0";
+	kp->input->dev.parent	= &pdev->dev;
+
+	kp->input->id.bustype	= BUS_HOST;
+	kp->input->id.vendor	= 0x0001;
+	kp->input->id.product	= 0x0001;
+	kp->input->id.version	= 0x0003;
+
+	kp->input->keycode	= kp->keymap;
+	kp->input->keycodesize	= sizeof(unsigned int);
+	kp->input->keycodemax	= kp->keymapsize;
+
+	ret = input_register_device(kp->input);
+	if (ret < 0) {
+		dev_err(kp->dbg_dev,
+			"Unable to register twl4030 keypad device\n");
+		goto err2;
+	}
+
+	/* Enable controller, with hardware decoding but not autorepeat */
+	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
+		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
+	ret = twl4030_kpwrite_u8(kp, reg, KEYP_CTRL);
+	if (ret < 0)
+		goto err3;
+
+	/* NOTE:  we don't use the sih_setup() here to package
+	 * the four keypad event sources as four different IRQs.
+	 */
+
+	/* Enable TO rising and KP rising and falling edge detection */
+	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
+	ret = twl4030_kpwrite_u8(kp, reg, KEYP_EDR);
+	if (ret < 0)
+		goto err3;
+
+	/* Set PTV prescaler Field */
+	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
+	ret = twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV);
+	if (ret < 0)
+		goto err3;
+
+	/* Set key debounce time to 20 ms */
+	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
+	ret = twl4030_kpwrite_u8(kp, i, KEYP_DEB);
+	if (ret < 0)
+		goto err3;
+
+	/* Set timeout period to 100 ms */
+	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
+	ret = twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L);
+	if (ret < 0)
+		goto err3;
+	ret = twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H);
+	if (ret < 0)
+		goto err3;
+
+	/* 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;
+	ret = twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL);
+	if (ret < 0)
+		goto err3;
+
+	/* initialize key state; irqs update it from here on */
+	ret = twl4030_read_kp_matrix_state(kp, kp->kp_state);
+	if (ret < 0)
+		goto err3;
+
+	/*
+	 * 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 ...
+	 */
+	ret = request_irq(kp->irq, do_kp_irq, 0, pdev->name, kp);
+	if (ret < 0) {
+		dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
+			kp->irq);
+		goto err3;
+	} else {
+		/* Enable KP and TO interrupts now. */
+		reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
+		ret = twl4030_kpwrite_u8(kp, reg, KEYP_IMR1);
+		if (ret < 0)
+			goto err5;
+	}
+
+	return ret;
+err5:
+	/* mask all events - we don't care about the result */
+	(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
+	free_irq(kp->irq, NULL);
+err3:
+	input_unregister_device(kp->input);
+err2:
+	input_free_device(kp->input);
+
+	return -ENODEV;
+}
+
+static int __devexit twl4030_kp_remove(struct platform_device *pdev)
+{
+	struct twl4030_keypad *kp = dev_get_drvdata(&pdev->dev);
+
+	free_irq(kp->irq, kp);
+	input_unregister_device(kp->input);
+	kfree(kp);
+
+	return 0;
+}
+
+MODULE_ALIAS("platform:twl4030_keypad");
+
+static struct platform_driver twl4030_kp_driver = {
+	.probe		= twl4030_kp_probe,
+	.remove		= __devexit_p(twl4030_kp_remove),
+	.driver		= {
+		.name	= "twl4030_keypad",
+		.owner	= THIS_MODULE,
+	},
+};
+
+/*
+ * OMAP TWL4030 Keypad init
+ */
+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");
--- a/include/linux/i2c/twl4030.h
+++ b/include/linux/i2c/twl4030.h
@@ -255,11 +255,18 @@ struct twl4030_madc_platform_data {
 	int		irq_line;
 };
 
+/* Boards have uniqe mappings of {col, row} --> keycode.
+ * Column and row are 4 bits, but range only from 0..7;
+ * a PERSISTENT_KEY is "always on" and never reported.
+ */
+#define KEY_PERSISTENT		0x00800000
+#define KEY(col, row, keycode)	(((col) << 28) | ((row) << 24) | (keycode))
+#define PERSISTENT_KEY(c, r)	KEY(c, r, KEY_PERSISTENT)
+
 struct twl4030_keypad_data {
 	int rows;
 	int cols;
 	int *keymap;
-	int irq;
 	unsigned int keymapsize;
 	unsigned int rep:1;
 };
--
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