diff mbox

[v4,2/2] Input: bcm-keypad: Add Broadcom keypad controller

Message ID 1425141357-7807-3-git-send-email-sbranden@broadcom.com (mailing list archive)
State New, archived
Headers show

Commit Message

Scott Branden Feb. 28, 2015, 4:35 p.m. UTC
Add driver for Broadcom's keypad controller.

Broadcom Keypad controller is used to interface a SoC with a matrix-type
keypad device. The keypad controller supports multiple row and column lines.
A key can be placed at each intersection of a unique row and a unique column.
The keypad controller can sense a key-press and key-release and report the
event using a interrupt to the cpu.

Reviewed-by: Ray Jui <rjui@broadcom.com>
Signed-off-by: Scott Branden <sbranden@broadcom.com>
---
 drivers/input/keyboard/Kconfig      |  10 +
 drivers/input/keyboard/Makefile     |   1 +
 drivers/input/keyboard/bcm-keypad.c | 463 ++++++++++++++++++++++++++++++++++++
 3 files changed, 474 insertions(+)
 create mode 100644 drivers/input/keyboard/bcm-keypad.c

Comments

Dmitry Torokhov Feb. 28, 2015, 10:10 p.m. UTC | #1
Hi Scott,

On Sat, Feb 28, 2015 at 08:35:57AM -0800, Scott Branden wrote:
> +	/* Enable clock */
> +
> +	kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
> +	if (IS_ERR(kp->clk)) {
> +		dev_info(&pdev->dev,
> +			"No clock specified. Assuming it's enabled\n");

I was doing the final pass before applying and I think that this is not
quite correct, as it does not handle -EPROBE_DEFER properly which is
quite common. I think we should do something like this:

		error = PTR_ERR(kp->clk);
		if (error != -ENOENT) {
			if (error != -EPROBE_DEFER)
				dev_err(.. "Failed to get clock" ...);
			return error;
		}
		dev_dbg(... "No clock specified" ...);

No need to resubmit if you are OK with this, I can make the change
locally.

> +	}
> +	else {

Checkpach should have warned you that it should have been "} else {";
I'll fix it up locally along with few other cosmetic changes and
dropping a few extra headers.

Thanks.
Dmitry Torokhov Feb. 28, 2015, 10:15 p.m. UTC | #2
On Sat, Feb 28, 2015 at 02:10:22PM -0800, Dmitry Torokhov wrote:
> Hi Scott,
> 
> On Sat, Feb 28, 2015 at 08:35:57AM -0800, Scott Branden wrote:
> > +	/* Enable clock */
> > +
> > +	kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
> > +	if (IS_ERR(kp->clk)) {
> > +		dev_info(&pdev->dev,
> > +			"No clock specified. Assuming it's enabled\n");
> 
> I was doing the final pass before applying and I think that this is not
> quite correct, as it does not handle -EPROBE_DEFER properly which is
> quite common. I think we should do something like this:
> 
> 		error = PTR_ERR(kp->clk);
> 		if (error != -ENOENT) {
> 			if (error != -EPROBE_DEFER)
> 				dev_err(.. "Failed to get clock" ...);
> 			return error;
> 		}
> 		dev_dbg(... "No clock specified" ...);
> 
> No need to resubmit if you are OK with this, I can make the change
> locally.

Hmm, also bcm_kp_start() and bcm_kp_stop() should check if kp->clk is
valid before trying to enable/disable it.

> 
> > +	}
> > +	else {
> 
> Checkpach should have warned you that it should have been "} else {";
> I'll fix it up locally along with few other cosmetic changes and
> dropping a few extra headers.
> 
> Thanks.
> 
> -- 
> Dmitry
Scott Branden March 2, 2015, 7:37 p.m. UTC | #3
Hi Dmitry,

I don't see the need for a check of the clock in bcm_kp_start or stop. 
See comment below.

On 15-02-28 02:15 PM, Dmitry Torokhov wrote:
> On Sat, Feb 28, 2015 at 02:10:22PM -0800, Dmitry Torokhov wrote:
>> Hi Scott,
>>
>> On Sat, Feb 28, 2015 at 08:35:57AM -0800, Scott Branden wrote:
>>> +	/* Enable clock */
>>> +
>>> +	kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
>>> +	if (IS_ERR(kp->clk)) {
>>> +		dev_info(&pdev->dev,
>>> +			"No clock specified. Assuming it's enabled\n");
>>
>> I was doing the final pass before applying and I think that this is not
>> quite correct, as it does not handle -EPROBE_DEFER properly which is
>> quite common. I think we should do something like this:
>>
>> 		error = PTR_ERR(kp->clk);
>> 		if (error != -ENOENT) {
>> 			if (error != -EPROBE_DEFER)
>> 				dev_err(.. "Failed to get clock" ...);
>> 			return error;
>> 		}
>> 		dev_dbg(... "No clock specified" ...);
>>
>> No need to resubmit if you are OK with this, I can make the change
>> locally.
>
> Hmm, also bcm_kp_start() and bcm_kp_stop() should check if kp->clk is
> valid before trying to enable/disable it.
>
I checked and other keyboard drivers do not check this.  I return an 
error in bcm_kp_start if the clk enable fails.  On stop, if the clk is 
not valid something is really, really wrong as well.
>>
>>> +	}
>>> +	else {
>>
>> Checkpach should have warned you that it should have been "} else {";
>> I'll fix it up locally along with few other cosmetic changes and
>> dropping a few extra headers.
>>
>> Thanks.
>>
>> --
>> Dmitry
>
Scott Branden March 2, 2015, 7:38 p.m. UTC | #4
Hi Dmitry,

Yes, please improve the driver and make the local change.

Regards,
  Scott

On 15-02-28 02:15 PM, Dmitry Torokhov wrote:
> On Sat, Feb 28, 2015 at 02:10:22PM -0800, Dmitry Torokhov wrote:
>> Hi Scott,
>>
>> On Sat, Feb 28, 2015 at 08:35:57AM -0800, Scott Branden wrote:
>>> +	/* Enable clock */
>>> +
>>> +	kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
>>> +	if (IS_ERR(kp->clk)) {
>>> +		dev_info(&pdev->dev,
>>> +			"No clock specified. Assuming it's enabled\n");
>>
>> I was doing the final pass before applying and I think that this is not
>> quite correct, as it does not handle -EPROBE_DEFER properly which is
>> quite common. I think we should do something like this:
>>
>> 		error = PTR_ERR(kp->clk);
>> 		if (error != -ENOENT) {
>> 			if (error != -EPROBE_DEFER)
>> 				dev_err(.. "Failed to get clock" ...);
>> 			return error;
>> 		}
>> 		dev_dbg(... "No clock specified" ...);
>>
>> No need to resubmit if you are OK with this, I can make the change
>> locally.
>
> Hmm, also bcm_kp_start() and bcm_kp_stop() should check if kp->clk is
> valid before trying to enable/disable it.
>
I am ok with these changes if you want to change locally.

>>
>>> +	}
>>> +	else {
>>
>> Checkpach should have warned you that it should have been "} else {";
>> I'll fix it up locally along with few other cosmetic changes and
>> dropping a few extra headers.
>>
>> Thanks.
>>
>> --
>> Dmitry
>
Dmitry Torokhov March 2, 2015, 8:23 p.m. UTC | #5
Hi Scott,

On Mon, Mar 02, 2015 at 11:37:57AM -0800, Scott Branden wrote:
> Hi Dmitry,
> 
> I don't see the need for a check of the clock in bcm_kp_start or
> stop. See comment below.
> 
> On 15-02-28 02:15 PM, Dmitry Torokhov wrote:
> >On Sat, Feb 28, 2015 at 02:10:22PM -0800, Dmitry Torokhov wrote:
> >>Hi Scott,
> >>
> >>On Sat, Feb 28, 2015 at 08:35:57AM -0800, Scott Branden wrote:
> >>>+	/* Enable clock */
> >>>+
> >>>+	kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
> >>>+	if (IS_ERR(kp->clk)) {
> >>>+		dev_info(&pdev->dev,
> >>>+			"No clock specified. Assuming it's enabled\n");
> >>
> >>I was doing the final pass before applying and I think that this is not
> >>quite correct, as it does not handle -EPROBE_DEFER properly which is
> >>quite common. I think we should do something like this:
> >>
> >>		error = PTR_ERR(kp->clk);
> >>		if (error != -ENOENT) {
> >>			if (error != -EPROBE_DEFER)
> >>				dev_err(.. "Failed to get clock" ...);
> >>			return error;
> >>		}
> >>		dev_dbg(... "No clock specified" ...);
> >>
> >>No need to resubmit if you are OK with this, I can make the change
> >>locally.
> >
> >Hmm, also bcm_kp_start() and bcm_kp_stop() should check if kp->clk is
> >valid before trying to enable/disable it.
> >
> I checked and other keyboard drivers do not check this.  I return an
> error in bcm_kp_start if the clk enable fails.  On stop, if the clk
> is not valid something is really, really wrong as well.

The other drivers simply abort probe() if they can't get clock, you
decided to allow probe() to finish and assume that clock is already
enabled, leaving kp->clk == ERR_PTR(-ENOENT) in your version. If you try
then calling clk_prepare_enable() with that pointer it is going to bomb,
that is why I said you need to check pointer validity in bcm_kp_start()
and bcm_kp_stop().

Thanks.
Scott Branden March 2, 2015, 9:59 p.m. UTC | #6
Hi Dmitry,

I understand what's missing now.

Thanks,
  Scott

On 15-03-02 12:23 PM, Dmitry Torokhov wrote:
> Hi Scott,
>
>>> Hmm, also bcm_kp_start() and bcm_kp_stop() should check if kp->clk is
>>> valid before trying to enable/disable it.
>>>
>> I checked and other keyboard drivers do not check this.  I return an
>> error in bcm_kp_start if the clk enable fails.  On stop, if the clk
>> is not valid something is really, really wrong as well.
>
> The other drivers simply abort probe() if they can't get clock, you
> decided to allow probe() to finish and assume that clock is already
> enabled, leaving kp->clk == ERR_PTR(-ENOENT) in your version. If you try
> then calling clk_prepare_enable() with that pointer it is going to bomb,
> that is why I said you need to check pointer validity in bcm_kp_start()
> and bcm_kp_stop().
>
> Thanks.
>
diff mbox

Patch

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index a5d9b3f..3a0c0f2 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -676,4 +676,14 @@  config KEYBOARD_CAP11XX
 	  To compile this driver as a module, choose M here: the
 	  module will be called cap11xx.
 
+config KEYBOARD_BCM
+	tristate "Broadcom keypad driver"
+	select INPUT_MATRIXKMAP
+	default ARCH_BCM_CYGNUS
+	help
+	  Say Y here if you want to use Broadcom keypad.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called bcm-keypad.
+
 endif
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index febafa5..3cff8f6 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -10,6 +10,7 @@  obj-$(CONFIG_KEYBOARD_ADP5589)		+= adp5589-keys.o
 obj-$(CONFIG_KEYBOARD_AMIGA)		+= amikbd.o
 obj-$(CONFIG_KEYBOARD_ATARI)		+= atakbd.o
 obj-$(CONFIG_KEYBOARD_ATKBD)		+= atkbd.o
+obj-$(CONFIG_KEYBOARD_BCM)		+= bcm-keypad.o
 obj-$(CONFIG_KEYBOARD_BFIN)		+= bf54x-keys.o
 obj-$(CONFIG_KEYBOARD_CAP11XX)		+= cap11xx.o
 obj-$(CONFIG_KEYBOARD_CLPS711X)		+= clps711x-keypad.o
diff --git a/drivers/input/keyboard/bcm-keypad.c b/drivers/input/keyboard/bcm-keypad.c
new file mode 100644
index 0000000..0fde149
--- /dev/null
+++ b/drivers/input/keyboard/bcm-keypad.c
@@ -0,0 +1,463 @@ 
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/sizes.h>
+#include <linux/stddef.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <asm/memory.h>
+#include <linux/io.h>
+#include <linux/input/matrix_keypad.h>
+
+#define DEFAULT_CLK_HZ                  31250
+/* Repeat period (ms) */
+#define KEY_REPEAT_PERIOD               100
+/* First time press dly (ms) */
+#define KEY_REPEAT_DELAY                400
+#define MAX_ROWS                        8
+#define MAX_COLS                        8
+
+/* Register/field definitions */
+#define KPCR_OFFSET                          0x00000080
+#define KPCR_MODE                       0x00000002
+#define KPCR_MODE_SHIFT                 1
+#define KPCR_MODE_MASK                  1
+#define KPCR_ENABLE                     0x00000001
+#define KPCR_STATUSFILTERENABLE         0x00008000
+#define KPCR_STATUSFILTERTYPE_SHIFT          12
+#define KPCR_COLFILTERENABLE            0x00000800
+#define KPCR_COLFILTERTYPE_SHIFT             8
+#define KPCR_ROWWIDTH_SHIFT                  20
+#define KPCR_COLUMNWIDTH_SHIFT               16
+
+#define KPIOR_OFFSET                         0x00000084
+#define KPIOR_ROWOCONTRL_SHIFT               24
+#define KPIOR_ROWOCONTRL_MASK                0xFF000000
+#define KPIOR_COLUMNOCONTRL_SHIFT            16
+#define KPIOR_COLUMNOCONTRL_MASK             0x00FF0000
+#define KPIOR_COLUMN_IO_DATA_SHIFT           0
+
+#define KPEMR0_OFFSET                        0x00000090
+#define KPEMR1_OFFSET                        0x00000094
+#define KPEMR2_OFFSET                        0x00000098
+#define KPEMR3_OFFSET                        0x0000009C
+#define KPEMR_EDGETYPE_BOTH 3
+
+#define KPSSR0_OFFSET                        0x000000A0
+#define KPSSR1_OFFSET                        0x000000A4
+#define KPSSRN_OFFSET(reg_n)                 (KPSSR0_OFFSET + (4 * reg_n))
+#define KPIMR0_OFFSET                        0x000000B0
+#define KPIMR1_OFFSET                        0x000000B4
+#define KPICR0_OFFSET                        0x000000B8
+#define KPICR1_OFFSET                        0x000000BC
+#define KPICRN_OFFSET(reg_n)                 (KPICR0_OFFSET + (4 * reg_n))
+#define KPISR0_OFFSET                        0x000000C0
+#define KPISR1_OFFSET                        0x000000C4
+
+#define KPCR_STATUSFILTERTYPE_MAX 7
+#define KPCR_COLFILTERTYPE_MAX 7
+
+/* Macros to determine the row/column from a bit that is set in SSR0/1. */
+#define BIT_TO_ROW_SSRN(bit_nr, reg_n)  ((bit_nr >> 3) + (4 * reg_n))
+#define BIT_TO_COL(bit_nr)       (bit_nr % 8)
+
+/* Structure representing various run-time entities */
+struct bcm_kp {
+	void __iomem *base;
+	int irq;
+	struct clk *clk;
+	struct input_dev *input_dev;
+	unsigned long last_state[2];
+	unsigned int n_rows;
+	unsigned int n_cols;
+	u32 kpcr;
+	u32 kpior;
+	u32 kpemr;
+	u32 imr0_val;
+	u32 imr1_val;
+};
+
+/*
+ * Returns the keycode from the input device keymap given the row and
+ * column.
+ */
+static inline int bcm_kp_get_keycode(struct bcm_kp *kp, int row, int col)
+{
+	unsigned int row_shift = get_count_order(kp->n_cols);
+	unsigned short *keymap = kp->input_dev->keycode;
+
+	return keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
+}
+
+static void bcm_kp_report_keys(struct bcm_kp *kp, int reg_num, int pull_mode)
+{
+	unsigned long state, change;
+	int bit_nr;
+	int key_press;
+	int row, col;
+	unsigned int keycode;
+
+	/* Clear interrupts */
+	writel(0xFFFFFFFF, kp->base + KPICRN_OFFSET(reg_num));
+
+	state = readl(kp->base + KPSSRN_OFFSET(reg_num));
+	change = kp->last_state[reg_num] ^ state;
+	kp->last_state[reg_num] = state;
+
+	for_each_set_bit(bit_nr, &change, BITS_PER_LONG) {
+		key_press = state & BIT(bit_nr);
+		/* The meaning of SSR register depends on pull mode. */
+		key_press = pull_mode ? !key_press : key_press;
+		row = BIT_TO_ROW_SSRN(bit_nr, reg_num);
+		col = BIT_TO_COL(bit_nr);
+		keycode = bcm_kp_get_keycode(kp, row, col);
+		input_report_key(kp->input_dev, keycode, key_press);
+	}
+}
+
+static irqreturn_t bcm_kp_isr_thread(int irq, void *dev_id)
+{
+	struct bcm_kp *kp = dev_id;
+	int pull_mode = (kp->kpcr >> KPCR_MODE_SHIFT) & KPCR_MODE_MASK;
+	int reg_num;
+
+	for (reg_num = 0; reg_num <= 1; reg_num++)
+		bcm_kp_report_keys(kp, reg_num, pull_mode);
+
+	input_sync(kp->input_dev);
+
+	return IRQ_HANDLED;
+}
+
+static int bcm_kp_start(struct bcm_kp *kp)
+{
+	int error;
+
+	error = clk_prepare_enable(kp->clk);
+	if (error)
+		return error;
+
+	writel(kp->kpior, kp->base + KPIOR_OFFSET);
+
+	writel(kp->imr0_val, kp->base + KPIMR0_OFFSET);
+	writel(kp->imr1_val, kp->base + KPIMR1_OFFSET);
+
+	writel(kp->kpemr, kp->base + KPEMR0_OFFSET);
+	writel(kp->kpemr, kp->base + KPEMR1_OFFSET);
+	writel(kp->kpemr, kp->base + KPEMR2_OFFSET);
+	writel(kp->kpemr, kp->base + KPEMR3_OFFSET);
+
+	writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
+	writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
+
+	kp->last_state[0] = readl(kp->base + KPSSR0_OFFSET);
+	kp->last_state[0] = readl(kp->base + KPSSR1_OFFSET);
+
+	writel(kp->kpcr | KPCR_ENABLE, kp->base + KPCR_OFFSET);
+
+	return 0;
+}
+
+static void bcm_kp_stop(const struct bcm_kp *kp)
+{
+	u32 val;
+
+	val = readl(kp->base + KPCR_OFFSET);
+	val &= ~KPCR_ENABLE;
+	writel(0, kp->base + KPCR_OFFSET);
+	writel(0, kp->base + KPIMR0_OFFSET);
+	writel(0, kp->base + KPIMR1_OFFSET);
+	writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
+	writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
+
+	clk_disable_unprepare(kp->clk);
+}
+
+static int bcm_kp_open(struct input_dev *dev)
+{
+	struct bcm_kp *kp = input_get_drvdata(dev);
+
+	return bcm_kp_start(kp);
+}
+
+static void bcm_kp_close(struct input_dev *dev)
+{
+	struct bcm_kp *kp = input_get_drvdata(dev);
+
+	bcm_kp_stop(kp);
+}
+
+static int bcm_kp_matrix_key_parse_dt(struct bcm_kp *kp)
+{
+	struct device *dev = kp->input_dev->dev.parent;
+	struct device_node *np = dev->of_node;
+	int error;
+	unsigned int dt_val;
+	unsigned int i;
+	unsigned int num_rows, col_mask, rows_set;
+
+	/* Initialize the KPCR Keypad Configuration Register */
+	kp->kpcr = KPCR_STATUSFILTERENABLE | KPCR_COLFILTERENABLE;
+
+	error = matrix_keypad_parse_of_params(dev, &kp->n_rows, &kp->n_cols);
+	if (error) {
+		dev_err(dev, "failed to parse kp params\n");
+		return error;
+	}
+	/* Set row width for the ASIC block. */
+	kp->kpcr |= (kp->n_rows - 1) << KPCR_ROWWIDTH_SHIFT;
+
+	/* Set column width for the ASIC block. */
+	kp->kpcr |= (kp->n_cols - 1) << KPCR_COLUMNWIDTH_SHIFT;
+
+	/* Configure the IMR registers */
+
+	/* 
+	 * IMR registers contain interrupt enable bits for 8x8 matrix
+	 * IMR0 register format: <row3> <row2> <row1> <row0>
+	 * IMR1 register format: <row7> <row6> <row5> <row4>
+	 */
+	col_mask = (1 << (kp->n_cols)) - 1;
+	num_rows = kp->n_rows;
+
+	/* Set column bits in rows 0 to 3 in IMR0 */
+	kp->imr0_val = col_mask;
+
+	rows_set = 1;
+	while ((--num_rows) && (rows_set++ < 4))
+		kp->imr0_val |= (kp->imr0_val << MAX_COLS);
+
+	/* Set column bits in rows 4 to 7 in IMR1 */
+	kp->imr1_val = 0;
+	if (num_rows) {
+		kp->imr1_val = col_mask;
+		while (--num_rows)
+			kp->imr1_val |= (kp->imr1_val << MAX_COLS);
+	}
+
+	/* Initialize the KPEMR Keypress Edge Mode Registers */
+	/* Trigger on both edges */
+	kp->kpemr = 0;
+	for (i = 0; i <= 30; i = i + 2)
+		kp->kpemr |= (KPEMR_EDGETYPE_BOTH << i);
+
+	/*
+	 * Obtain the Status filter debounce value and verify against the
+	 * possible values specified in the DT binding.
+	 */
+	of_property_read_u32(np, "status-debounce-filter-period",
+		&dt_val);
+	if (dt_val > KPCR_STATUSFILTERTYPE_MAX) {
+		dev_err(dev, "Invalid Status filter debounce value %d\n",
+			dt_val);
+		return -EINVAL;
+	}
+	kp->kpcr |= dt_val << KPCR_STATUSFILTERTYPE_SHIFT;
+
+
+	/*
+	 * Obtain the Column filter debounce value and verify against the
+	 * possible values specified in the DT binding.
+	 */
+	of_property_read_u32(np, "col-debounce-filter-period",
+		&dt_val);
+
+	if (dt_val > KPCR_COLFILTERTYPE_MAX) {
+		dev_err(dev, "Invalid Column filter debounce value %d\n",
+			dt_val);
+		return -EINVAL;
+	}
+	kp->kpcr |= dt_val << KPCR_COLFILTERTYPE_SHIFT;
+
+	/*
+	 * Determine between the row and column,
+	 * which should be configured as output.
+	 */
+	if (of_property_read_bool(np, "row-output-enabled")) {
+		/*
+		* Set RowOContrl or ColumnOContrl in KPIOR
+		* to the number of pins to drive as outputs
+		*/
+		kp->kpior = (((1 << kp->n_rows) - 1) <<
+				KPIOR_ROWOCONTRL_SHIFT);
+	} else {
+		kp->kpior = (((1 << kp->n_cols) - 1) <<
+				KPIOR_COLUMNOCONTRL_SHIFT);
+	}
+
+	/*
+	 * Determine if the scan pull up needs to be enabled
+	 */
+	if (of_property_read_bool(np, "pull-up-enabled"))
+		kp->kpcr |= KPCR_MODE;
+
+	dev_dbg(dev, "n_rows=%d n_col=%d kpcr=%x kpior=%x kpemr=%x\n",
+		kp->n_rows, kp->n_cols,
+		kp->kpcr, kp->kpior, kp->kpemr);
+
+	return 0;
+}
+
+
+static int bcm_kp_probe(struct platform_device *pdev)
+{
+	struct bcm_kp *kp;
+	struct input_dev *input_dev;
+	struct resource *res;
+	int error;
+	bool repeat;
+
+	kp = devm_kzalloc(&pdev->dev, sizeof(*kp),
+				   GFP_KERNEL);
+	if (!kp)
+		return -ENOMEM;
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev) {
+		dev_err(&pdev->dev, "failed to allocate the input device\n");
+		return -ENOMEM;
+	}
+
+	__set_bit(EV_KEY, input_dev->evbit);
+
+	repeat = !!of_get_property(pdev->dev.of_node, "autorepeat", NULL);
+	/* Enable auto repeat feature of Linux input subsystem */
+	if (repeat)
+		__set_bit(EV_REP, input_dev->evbit);
+
+	input_dev->name = pdev->name;
+	input_dev->phys = "keypad/input0";
+	input_dev->dev.parent = &pdev->dev;
+	input_dev->open = bcm_kp_open;
+	input_dev->close = bcm_kp_close;
+
+	input_dev->id.bustype = BUS_HOST;
+	input_dev->id.vendor = 0x0001;
+	input_dev->id.product = 0x0001;
+	input_dev->id.version = 0x0100;
+
+	input_set_drvdata(input_dev, kp);
+
+	kp->input_dev = input_dev;
+
+	platform_set_drvdata(pdev, kp);
+
+	error = bcm_kp_matrix_key_parse_dt(kp);
+	if (error)
+		return error;
+
+	error = matrix_keypad_build_keymap(NULL, NULL,
+					   kp->n_rows,
+					   kp->n_cols,
+					   NULL, input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to build keymap\n");
+		return error;
+	}
+
+	/* Get the KEYPAD base address */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Missing keypad base address resource\n");
+		return -ENODEV;
+	}
+
+	kp->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(kp->base))
+		return PTR_ERR(kp->base);
+
+	/* Enable clock */
+
+	kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
+	if (IS_ERR(kp->clk)) {
+		dev_info(&pdev->dev,
+			"No clock specified. Assuming it's enabled\n");
+	}
+	else {
+		unsigned int desired_rate;
+		long actual_rate;
+
+		error = of_property_read_u32(pdev->dev.of_node,
+				"clock-frequency", &desired_rate);
+		if (error < 0)
+			desired_rate = DEFAULT_CLK_HZ;
+
+		actual_rate = clk_round_rate(kp->clk, desired_rate);
+		if (actual_rate <= 0)
+			return -EINVAL;
+
+		error = clk_set_rate(kp->clk, actual_rate);
+		if (error)
+			return -EINVAL;
+
+		error = clk_prepare_enable(kp->clk);
+		if (error)
+			return -EINVAL;
+	}
+
+	/* Put the kp into a known sane state */
+	bcm_kp_stop(kp);
+
+	kp->irq = platform_get_irq(pdev, 0);
+	if (kp->irq < 0) {
+		dev_err(&pdev->dev, "no IRQ specified\n");
+		return -EINVAL;
+	}
+
+	error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL,
+		bcm_kp_isr_thread,
+		IRQF_ONESHOT, pdev->name, kp);
+	if (error) {
+		dev_err(&pdev->dev, "failed to request IRQ\n");
+		return error;
+	}
+
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		return error;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id bcm_kp_of_match[] = {
+	{ .compatible = "brcm,bcm-keypad" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, bcm_kp_of_match);
+
+static struct platform_driver bcm_kp_device_driver = {
+	.probe		= bcm_kp_probe,
+	.driver		= {
+		.name	= "bcm-keypad",
+		.of_match_table = of_match_ptr(bcm_kp_of_match),
+	}
+};
+
+module_platform_driver(bcm_kp_device_driver);
+
+MODULE_AUTHOR("Broadcom Corporation");
+MODULE_DESCRIPTION("BCM Keypad Driver");
+MODULE_LICENSE("GPL v2");