Re: [PATCH 1/2] Input: DaVinci Keypad Driver

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Miguel,

On Tue, Sep 22, 2009 at 03:27:30PM -0600, miguel.aguilar@ridgerun.com wrote:
> From: Miguel Aguilar <miguel.aguilar@ridgerun.com>
> 
> Adds the driver for enabling keypad support for DaVinci platforms.
> 
> DM365 is the only platform that uses this driver at the moment.
> 
> This driver was tested on DM365 EVM rev C.
> 
> Signed-off-by: Miguel Aguilar <miguel.aguilar@ridgerun.com>
> ---
>  arch/arm/configs/davinci_all_defconfig      |    1 +
>  arch/arm/mach-davinci/include/mach/keypad.h |   35 +++
>  drivers/input/keyboard/Kconfig              |    7 +
>  drivers/input/keyboard/Makefile             |    1 +
>  drivers/input/keyboard/davinci_keypad.c     |  319 +++++++++++++++++++++++++++
>  5 files changed, 363 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/mach-davinci/include/mach/keypad.h
>  create mode 100644 drivers/input/keyboard/davinci_keypad.c
> 
> diff --git a/arch/arm/configs/davinci_all_defconfig b/arch/arm/configs/davinci_all_defconfig
> index ec63c15..e994c83 100644
> --- a/arch/arm/configs/davinci_all_defconfig
> +++ b/arch/arm/configs/davinci_all_defconfig
> @@ -763,6 +763,7 @@ CONFIG_KEYBOARD_GPIO=y
>  # CONFIG_KEYBOARD_STOWAWAY is not set
>  # CONFIG_KEYBOARD_SUNKBD is not set
>  CONFIG_KEYBOARD_XTKBD=m
> +CONFIG_KEYBOARD_DAVINCI_DM365=m
>  # CONFIG_INPUT_MOUSE is not set
>  # CONFIG_INPUT_JOYSTICK is not set
>  # CONFIG_INPUT_TABLET is not set


If you want to merge the driver through input tree the defconfig chunk
has to go elsewhere.

> diff --git a/arch/arm/mach-davinci/include/mach/keypad.h b/arch/arm/mach-davinci/include/mach/keypad.h
> new file mode 100644
> index 0000000..922d20e
> --- /dev/null
> +++ b/arch/arm/mach-davinci/include/mach/keypad.h
> @@ -0,0 +1,35 @@
> +/*
> + * Copyright (C) 2009 Texas Instruments, Inc
> + *
> + * Author: Miguel Aguilar <miguel.aguilar@ridgerun.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
> + */
> +
> +#ifndef DAVINCI_KEYPAD_H
> +#define DAVINCI_KEYPAD_H
> +
> +#include <linux/io.h>
> +
> +struct davinci_kp_platform_data {
> +	int	*keymap;
> +	u32	keymapsize;
> +	u32	rep:1;
> +	u32	strobe;
> +	u32	interval;
> +};
> +
> +#endif
> +
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index a6b989a..b6b9517 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -361,4 +361,11 @@ config KEYBOARD_XTKBD
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called xtkbd.
>  
> +config KEYBOARD_DAVINCI
> +	tristate "TI DaVinci Keypad"
> +	depends on ARCH_DAVINCI_DM365
> +	help
> +	  Say Y to enable keypad module support for the TI DaVinci
> +	  platforms (DM365)
> +

"To compile this driver as a module..."

>  endif
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index b5b5eae..0b0274e 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -31,3 +31,4 @@ obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
>  obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
>  obj-$(CONFIG_KEYBOARD_TOSA)		+= tosakbd.o
>  obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
> +obj-$(CONFIG_KEYBOARD_DAVINCI)		+= davinci_keypad.o
> diff --git a/drivers/input/keyboard/davinci_keypad.c b/drivers/input/keyboard/davinci_keypad.c
> new file mode 100644
> index 0000000..6f0e793
> --- /dev/null
> +++ b/drivers/input/keyboard/davinci_keypad.c
> @@ -0,0 +1,319 @@
> +/*
> + * DaVinci Keypad Driver for TI platforms
> + *
> + * Copyright (C) 2009 Texas Instruments, Inc
> + *
> + * Author: Miguel Aguilar <miguel.aguilar@ridgerun.com>
> + *
> + * Intial Code: Sandeep Paulraj <s-paulraj@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/module.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/types.h>
> +#include <linux/input.h>
> +#include <linux/kernel.h>
> +#include <linux/delay.h>
> +#include <linux/platform_device.h>
> +#include <linux/errno.h>
> +
> +#include <asm/irq.h>
> +
> +#include <mach/hardware.h>
> +#include <mach/irqs.h>
> +#include <mach/keypad.h>
> +
> +/* Keypad registers */
> +#define DAVINCI_KEYPAD_KEYCTRL		0x0000
> +#define DAVINCI_KEYPAD_INTENA		0x0004
> +#define DAVINCI_KEYPAD_INTFLAG		0x0008
> +#define DAVINCI_KEYPAD_INTCLR		0x000c
> +#define DAVINCI_KEYPAD_STRBWIDTH	0x0010
> +#define DAVINCI_KEYPAD_INTERVAL		0x0014
> +#define DAVINCI_KEYPAD_CONTTIME		0x0018
> +#define DAVINCI_KEYPAD_CURRENTST	0x001c
> +#define DAVINCI_KEYPAD_PREVSTATE	0x0020
> +#define DAVINCI_KEYPAD_EMUCTRL		0x0024
> +#define DAVINCI_KEYPAD_IODFTCTRL	0x002c
> +
> +/* Key Control Register (KEYCTRL) */
> +#define DAVINCI_KEYPAD_KEYEN		0x00000001
> +#define DAVINCI_KEYPAD_PREVMODE		0x00000002
> +#define DAVINCI_KEYPAD_CHATOFF		0x00000004
> +#define DAVINCI_KEYPAD_AUTODET		0x00000008
> +#define DAVINCI_KEYPAD_SCANMODE		0x00000010
> +#define DAVINCI_KEYPAD_OUTTYPE		0x00000020
> +#define DAVINCI_KEYPAD_4X4		0x00000040
> +
> +/* Masks for the interrupts */
> +#define DAVINCI_KEYPAD_INT_CONT		0x00000008
> +#define DAVINCI_KEYPAD_INT_OFF		0x00000004
> +#define DAVINCI_KEYPAD_INT_ON		0x00000002
> +#define DAVINCI_KEYPAD_INT_CHANGE	0x00000001
> +#define DAVINCI_KEYPAD_INT_ALL		0x0000000f
> +
> +struct davinci_kp {
> +	struct input_dev		*input;
> +	struct davinci_kp_platform_data	*pdata;
> +	int				irq;
> +	void __iomem			*base;
> +	resource_size_t			pbase;
> +	size_t				base_size;
> +};
> +
> +static void davinci_kp_write(struct davinci_kp *davinci_kp, u32 val, u32 addr)
> +{
> +	u32 base = (u32)davinci_kp->base;
> +
> +	__raw_writel(val,(u32 *)(base + addr));
> +}
> +
> +static u32 davinci_kp_read(struct davinci_kp *davinci_kp, u32 addr)
> +{
> +	u32 base = (u32)davinci_kp->base;
> +
> +	return __raw_readl((u32 *)(base + addr));
> +}
> +
> +/* Initializing the kp Module */
> +static void davinci_kp_initialize(struct davinci_kp *davinci_kp)
> +{
> +	u32 strobe = davinci_kp->pdata->strobe;
> +	u32 interval = davinci_kp->pdata->interval;
> +
> +	/* Enable all interrupts */
> +	davinci_kp_write(davinci_kp, DAVINCI_KEYPAD_INT_ALL, DAVINCI_KEYPAD_INTENA);
> +
> +	/* Clear interrupts if any */
> +	davinci_kp_write(davinci_kp, DAVINCI_KEYPAD_INT_ALL, DAVINCI_KEYPAD_INTCLR);
> +
> +	/* Setup the scan period = strobe + interval */
> +	davinci_kp_write(davinci_kp, strobe, DAVINCI_KEYPAD_STRBWIDTH);
> +	davinci_kp_write(davinci_kp, interval, DAVINCI_KEYPAD_INTERVAL);
> +	davinci_kp_write(davinci_kp, 0x01, DAVINCI_KEYPAD_CONTTIME);
> +
> +	/* Enable Keyscan module and enable */
> +	davinci_kp_write(davinci_kp, DAVINCI_KEYPAD_AUTODET | DAVINCI_KEYPAD_KEYEN,
> +			DAVINCI_KEYPAD_KEYCTRL);
> +}
> +
> +static irqreturn_t davinci_kp_interrupt(int irq, void *dev_id)
> +{
> +	struct davinci_kp *davinci_kp = dev_id;
> +	struct device *dev = &davinci_kp->input->dev;
> +	int *keymap = davinci_kp->pdata->keymap;
> +		u32 prev_status, new_status, changed, position;
> +	int keycode = KEY_UNKNOWN;
> +	int ret = IRQ_NONE;
> +
> +	/* Disable interrupt */
> +	davinci_kp_write(davinci_kp, 0x0, DAVINCI_KEYPAD_INTENA);
> +
> +	/* Reading previous and new status of the keypad */
> +	prev_status = davinci_kp_read(davinci_kp, DAVINCI_KEYPAD_PREVSTATE);
> +	new_status = davinci_kp_read(davinci_kp, DAVINCI_KEYPAD_CURRENTST);
> +
> +	changed = prev_status ^ new_status;
> +	position = ffs(changed) - 1;
> +
> +	if (changed) {

Can there be several buttons that change status at once?

> +		keycode = keymap[position];
> +		if((new_status >> position) & 0x1) {

bool release = (new_status >> position) & 0x1;
input_report_key(davinci_kp->input, keycode, !release);
dev_dbg(dev, "davinci_keypad: key %d %s\n",
	keycode, release ? "released" : "pressed");

is shorter.

> +			/* Report release */
> +			dev_dbg(dev, "davinci_keypad: key %d released\n",
> +				    keycode);
> +			input_report_key(davinci_kp->input, keycode, 0);
> +		} else {
> +			/* Report press */
> +			dev_dbg(dev, "davinci_keypad: key %d pressed\n",
> +				    keycode);
> +			input_report_key(davinci_kp->input, keycode, 1);
> +		}
> +		input_sync(davinci_kp->input);
> +		ret = IRQ_HANDLED;
> +	}
> +
> +	/* Clearing interrupt */
> +	davinci_kp_write(davinci_kp, DAVINCI_KEYPAD_INT_ALL, DAVINCI_KEYPAD_INTCLR);

You return IRQ_HANDLED only if keypad state changed but clear interrupt
regardless. This is suspicious.

> +
> +	/* Enable interrupts */
> +	davinci_kp_write(davinci_kp, 0x1, DAVINCI_KEYPAD_INTENA);
> +
> +	return ret;
> +}
> +
> +static int __init davinci_kp_probe(struct platform_device *pdev)
> +{
> +	struct davinci_kp *davinci_kp;
> +	struct input_dev *key_dev;
> +	struct resource *res, *mem;
> +	int ret, i;
> +	struct device * dev = &pdev->dev;
> +	struct davinci_kp_platform_data *pdata = pdev->dev.platform_data;
> +
> +	dev_info(dev, "DaVinci Keypad Driver\n");
> +
> +	if (!pdata->keymap) {
> +		dev_dbg(dev, "no keymap from pdata\n");
> +		return -EINVAL;
> +	}
> +
> +	davinci_kp = kzalloc(sizeof *davinci_kp, GFP_KERNEL);
> +	if(!davinci_kp) {
> +		dev_dbg(dev, "could not allocate memory for private data\n");
> +		return -ENOMEM;
> +	}
> +
> +	key_dev = input_allocate_device();
> +	if (!key_dev) {
> +		dev_dbg(dev, "could not allocate input device\n");
> +		ret = -ENOMEM;
> +		goto fail1;
> +	}
> +
> +	platform_set_drvdata(pdev, davinci_kp);
> +
> +	davinci_kp->input = key_dev;
> +
> +	davinci_kp->irq = platform_get_irq(pdev, 0);
> +	if (davinci_kp->irq < 0) {
> +		dev_err(dev, "no keypad irq\n");
> +		ret = davinci_kp->irq;
> +		goto fail2;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "no mem resource\n");
> +		ret = -ENODEV;

-EINVAL I'd say.

> +		goto fail2;
> +	}
> +
> +	davinci_kp->pbase = res->start;
> +	davinci_kp->base_size = resource_size(res);
> +
> +	mem = request_mem_region(davinci_kp->pbase, davinci_kp->base_size, pdev->name);
> +	if (!mem) {
> +		dev_err(dev, "KEYSCAN registers at %08x are not free\n",
> +			davinci_kp->pbase);
> +		ret = -EBUSY;
> +		goto fail2;
> +	}
> +
> +	davinci_kp->base = ioremap(davinci_kp->pbase, davinci_kp->base_size);
> +	if (!davinci_kp->base) {
> +		dev_err(dev, "can't ioremap MEM resource.\n");
> +		ret = -ENOMEM;
> +		goto fail3;
> +	}
> +
> +	/* Enable auto repeat feature of Linux input subsystem */
> +	if (pdata->rep)
> +		__set_bit(EV_REP, key_dev->evbit);
> +
> +	/* Setup input device */
> +	__set_bit(EV_KEY, key_dev->evbit);
> +
> +	/* Setup the keymap */
> +	davinci_kp->pdata = pdata;
> +
> +	for (i = 0; i < davinci_kp->pdata->keymapsize; i++)
> +		__set_bit(davinci_kp->pdata->keymap[i], key_dev->keybit);
> +
> +	key_dev->name = "davinci_keypad";
> +	key_dev->phys = "davinci_keypad/input0";
> +	key_dev->dev.parent = &pdev->dev;
> +	key_dev->id.bustype = BUS_HOST;
> +	key_dev->id.vendor = 0x0001;
> +	key_dev->id.product = 0x0001;
> +	key_dev->id.version = 0x0001;
> +	key_dev->keycode = davinci_kp->pdata->keymap;

Please kopy keymap into the davinci_kp stucture and use it so that
platform data is never changed and can be declared const.

> +	key_dev->keycodesize = sizeof(unsigned int);

sizeof(davinci_kp->keymap[0]) is safer. Plus make it unsigned short.

> +	key_dev->keycodemax = davinci_kp->pdata->keymapsize;
> +
> +	ret = input_register_device(davinci_kp->input);
> +	if (ret < 0) {
> +		dev_err(dev, "unable to register DaVinci keypad device\n");
> +		goto fail4;
> +	}
> +
> +	ret = request_irq(davinci_kp->irq, davinci_kp_interrupt, IRQF_DISABLED,
> +                         "davinci_keypad", davinci_kp);
> +	if (ret < 0) {
> +		dev_err(dev, "unable to register DaVinci keypad Interrupt\n");
> +		goto fail5;
> +	}
> +
> +	davinci_kp_initialize(davinci_kp);
> +
> +	return 0;
> +fail5:
> +	input_unregister_device(davinci_kp->input);
> +	key_dev = NULL;
> +fail4:
> +	iounmap(davinci_kp->base);
> +fail3:
> +	release_mem_region(davinci_kp->pbase, davinci_kp->base_size);
> +fail2:
> +	input_free_device(key_dev);
> +fail1:
> +	kfree(davinci_kp);
> +
> +	return ret;
> +}
> +
> +static int __exit davinci_kp_remove(struct platform_device *pdev)

__devexit?

> +{
> +	struct davinci_kp *davinci_kp = platform_get_drvdata(pdev);
> +
> +	free_irq(davinci_kp->irq, davinci_kp);
> +
> +	input_unregister_device(davinci_kp->input);
> +
> +	iounmap(davinci_kp->base);
> +	release_mem_region(davinci_kp->pbase, davinci_kp->base_size);
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	kfree(davinci_kp);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver davinci_kp_driver = {
> +	.driver = {
> +			.name = "davinci_keypad",
> +			.owner = THIS_MODULE,
> +		},
> +	.remove = __exit_p(davinci_kp_remove),

__devexit_p(). I think you can still unbind the device even if you use
platform_driver_probe.

> +};
> +
> +static int __init davinci_kp_init(void)
> +{
> +	return platform_driver_probe(&davinci_kp_driver, davinci_kp_probe);
> +}
> +module_init(davinci_kp_init);
> +
> +static void __exit davinci_kp_exit(void)
> +{
> +	platform_driver_unregister(&davinci_kp_driver);
> +}
> +module_exit(davinci_kp_exit);
> +
> +MODULE_AUTHOR("Miguel Aguilar");
> +MODULE_DESCRIPTION("Texas Instruments DaVinci Keypad Driver");
> +MODULE_LICENSE("GPL");
> -- 
> 1.6.0.4
> 
> --
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-- 
Dmitry