Re: [PATCH 2/7] input: add driver for tnetv107x on-chip keypad controller

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

On Mon, Sep 13, 2010 at 12:29:43PM -0400, Cyril Chemparathy wrote:
> This patch adds support for tnetv107x's on-chip keypad controller.
> 
> Signed-off-by: Cyril Chemparathy <cyril@ti.com>
> ---
>  drivers/input/keyboard/Kconfig            |    9 +
>  drivers/input/keyboard/Makefile           |    1 +
>  drivers/input/keyboard/tnetv107x-keypad.c |  324 +++++++++++++++++++++++++++++
>  3 files changed, 334 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/input/keyboard/tnetv107x-keypad.c
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index 9cc488d..0ea8648 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -457,4 +457,13 @@ config KEYBOARD_W90P910
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called w90p910_keypad.
>  
> +config KEYBOARD_TNETV107X
> +	tristate "TI TNETV107X keypad support"
> +	depends on ARCH_DAVINCI_TNETV107X
> +	help
> +	  Say Y here if you want to use the TNETV107X keypad.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called tnetv107x-keypad.
> +
>  endif
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index 504b591..63261b0 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -41,3 +41,4 @@ obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
>  obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
>  obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
>  obj-$(CONFIG_KEYBOARD_W90P910)		+= w90p910_keypad.o
> +obj-$(CONFIG_KEYBOARD_TNETV107X)	+= tnetv107x-keypad.o

Please keep makefile and Kconfig sorted alphabetically please.

> diff --git a/drivers/input/keyboard/tnetv107x-keypad.c b/drivers/input/keyboard/tnetv107x-keypad.c
> new file mode 100644
> index 0000000..5039164
> --- /dev/null
> +++ b/drivers/input/keyboard/tnetv107x-keypad.c
> @@ -0,0 +1,324 @@
> +/*
> + * Texas Instruments TNETV107X Keypad Driver
> + *
> + * Copyright (C) 2010 Texas Instruments
> + *
> + * 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/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/input.h>
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/clk.h>
> +
> +#include <mach/tnetv107x.h>
> +
> +#define KEYPAD_ROWS		9
> +#define KEYPAD_COLS		9
> +
> +struct keypad_regs {
> +	u32	rev;
> +	u32	mode;
> +	u32	mask;
> +	u32	pol;
> +	u32	dclock;
> +	u32	rclock;
> +	u32	stable_cnt;
> +	u32	in_en;
> +	u32	out;
> +	u32	out_en;
> +	u32	in;
> +	u32	lock;
> +	u32	pres[3];
> +};
> +
> +#define keypad_read(kp, reg)		__raw_readl(&(kp)->regs->reg)
> +#define keypad_write(kp, reg, val)	__raw_writel(val, &(kp)->regs->reg)
> +
> +struct keypad_data {
> +	struct tnetv107x_keypad_data	data;
> +	struct input_dev		*input_dev;
> +	struct resource			*res;
> +	struct keypad_regs __iomem	*regs;
> +	struct clk			*clk;
> +	struct device			*dev;
> +	u32				irq_press;
> +	u32				irq_release;
> +	u32				curr_keys[3];
> +	u32				prev_keys[3];
> +};
> +
> +static void handle_change(struct keypad_data *kp)
> +{
> +	int bit, i;
> +
> +	for (bit = 0; bit < (KEYPAD_ROWS * KEYPAD_COLS); bit++) {
> +		int idx		= bit / 32;
> +		u32 mask	= 1 << (bit % 32);
> +		u32 curr	= kp->curr_keys[idx] & mask;
> +		u32 prev	= kp->prev_keys[idx] & mask;
> +		int row		= bit / KEYPAD_COLS;
> +		int col		= bit % KEYPAD_COLS;
> +		int ofs		= row * kp->data.cols + col;
> +
> +		if (col >= kp->data.cols || row >= kp->data.rows)
> +			continue;
> +
> +		if (curr && !prev) {
> +			/* Report key press */
> +			if (kp->data.keynames && kp->data.keynames[ofs])
> +				dev_dbg(kp->dev, "%s (%d) pressed\n",
> +					kp->data.keynames[ofs], ofs);
> +			input_report_key(kp->input_dev,
> +					 kp->data.keymap[ofs], 1);
> +		} else if (!curr && prev) {
> +			/* Report key release */
> +			if (kp->data.keynames && kp->data.keynames[ofs])
> +				dev_dbg(kp->dev, "%s (%d) released\n",
> +					kp->data.keynames[ofs], ofs);
> +			input_report_key(kp->input_dev,
> +					 kp->data.keymap[ofs], 0);
> +		}

This is called xor.

Also, instead of printing key names just send EV_MSC/MSC_SCAN - much
more useful.

> +	}
> +
> +	/* Update shadow copy */
> +	for (i = 0; i < 3; i++)
> +		kp->prev_keys[i] = kp->curr_keys[i];

memcpy(kp->prev_keys, kp->curr_keys, sizeof(kp->prev_keys));

> +
> +	input_sync(kp->input_dev);
> +}
> +
> +static irqreturn_t keypad_irq_press(int irq, void *data)
> +{
> +	struct keypad_data *kp = (struct keypad_data *)data;
> +	int i;
> +
> +	for (i = 0; i < 3; i++)
> +		kp->curr_keys[i] = keypad_read(kp, pres[i]);
> +	handle_change(kp);
> +	keypad_write(kp, lock, 0); /* Allow hardware updates */
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t keypad_irq_release(int irq, void *data)
> +{
> +	struct keypad_data *kp = (struct keypad_data *)data;
> +	int i;
> +
> +	/* Hardware says all keys have been released */
> +	for (i = 0; i < 3; i++)
> +		kp->curr_keys[i] = 0;

	memset(kp->curr_keys, 0, sizeof(kp->curr_keys));

> +	handle_change(kp);
> +	return IRQ_HANDLED;
> +}
> +
> +static int tnetv107x_keypad_probe(struct platform_device *pdev)
> +{
> +	struct tnetv107x_keypad_data *pdata = pdev->dev.platform_data;

This should be const.

> +	struct device *dev = &pdev->dev;
> +	struct keypad_data *kp;
> +	int i, ret = 0;
> +	u32 rev = 0;
> +
> +	ret = -EINVAL;
> +	if (!pdata) {
> +		dev_err(dev, "cannot find device data\n");
> +		return ret;
> +	}

Please assign error code in the error branch. I also prefer variable
be called error if possible.

> +
> +	ret = -ENOMEM;
> +	kp = kzalloc(sizeof(struct keypad_data), GFP_KERNEL);
> +	if (!kp) {
> +		dev_err(dev, "cannot allocate device info\n");
> +		return ret;
> +	}
> +
> +	dev_set_drvdata(dev, kp);
> +	kp->data = *pdata;
> +	kp->dev = dev;
> +
> +	ret = -ENOMEM;
> +	kp->input_dev = input_allocate_device();
> +	if (!kp->input_dev) {
> +		dev_err(dev, "cannot allocate input device\n");
> +		goto error0;
> +	}
> +
> +	ret = -ENODEV;
> +	kp->irq_press   = platform_get_irq_byname(pdev, "press");
> +	kp->irq_release = platform_get_irq_byname(pdev, "release");
> +	if (kp->irq_press < 0 || kp->irq_release < 0) {
> +		dev_err(dev, "cannot determine device interrupts\n");
> +		goto error1;
> +	}
> +
> +	ret = -ENODEV;
> +	kp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!kp->res) {
> +		dev_err(dev, "cannot determine register area\n");
> +		goto error1;
> +	}
> +
> +	ret = -EINVAL;
> +	if (!request_mem_region(kp->res->start, resource_size(kp->res),
> +				pdev->name)) {
> +		dev_err(dev, "cannot claim register memory\n");
> +		goto error1;
> +	}
> +
> +	ret = -ENOMEM;
> +	kp->regs = ioremap(kp->res->start, resource_size(kp->res));
> +	if (!kp->regs) {
> +		dev_err(dev, "cannot map register memory\n");
> +		goto error2;
> +	}
> +
> +	ret = -EINVAL;
> +	kp->clk = clk_get(dev, NULL);
> +	if (!kp->clk) {
> +		dev_err(dev, "cannot claim device clock\n");
> +		goto error3;
> +	}
> +	clk_enable(kp->clk);
> +
> +	/* Initialize device registers */
> +	keypad_write(kp, mode, 0);
> +	keypad_write(kp, mask, ~((((1 << kp->data.rows)-1) << 9) |
> +			   (((1 << kp->data.cols)-1))));
> +	keypad_write(kp, pol, 0x3ffff);
> +	keypad_write(kp, dclock, kp->data.debounce);
> +	keypad_write(kp, rclock, 4*kp->data.debounce);
> +	keypad_write(kp, stable_cnt, kp->data.stable);
> +
> +	/* Enable Input */
> +	keypad_write(kp, in_en, 0);
> +	mdelay(1);
> +	keypad_write(kp, in_en, 1);
> +
> +	ret = request_irq(kp->irq_press, keypad_irq_press, 0,
> +			  "keypad-press", kp);
> +	if (ret < 0) {
> +		dev_err(dev, "Could not allocate keypad press key irq\n");
> +		goto error4;
> +	}
> +
> +	ret = request_irq(kp->irq_release, keypad_irq_release, 0,
> +			  "keypad-release", kp);
> +	if (ret < 0) {
> +		dev_err(dev, "Could not allocate keypad release key irq\n");
> +		goto error5;
> +	}
> +
> +	set_bit(EV_KEY, kp->input_dev->evbit);
> +	for (i = 0; i < kp->data.keymap_size; i++)
> +		set_bit(kp->data.keymap[i] & KEY_MAX, kp->input_dev->keybit);
> +
> +	kp->input_dev->name = "tnetv107x-keypad";
> +	kp->input_dev->phys = "tnetv107x-keypad/input0";
> +	kp->input_dev->dev.parent = &pdev->dev;
> +	kp->input_dev->id.bustype = BUS_HOST;
> +	kp->input_dev->id.vendor = 0x0001;
> +
> +	rev = keypad_read(kp, rev);
> +	kp->input_dev->id.product = ((rev >>  8) & 0x07);
> +	kp->input_dev->id.version = ((rev >> 16) & 0xfff);
> +
> +	kp->input_dev->keycode = kp->data.keymap;
> +	kp->input_dev->keycodesize = sizeof(int);
> +	kp->input_dev->keycodemax = kp->data.keymap_size;

Since you allow changing data keymap should be moved into per-device
instance (platform data should be kept constant).

> +	ret = input_register_device(kp->input_dev);
> +	if (ret < 0) {
> +		dev_err(dev, "Could not register input device\n");
> +		goto error6;
> +	}
> +
> +	dev_info(dev, "registered keypad device\n");

Input core already emits message when new device is registered, should
be enough.

> +	return 0;
> +
> +error6:
> +	free_irq(kp->irq_release, kp);
> +error5:
> +	free_irq(kp->irq_press, kp);
> +error4:
> +	clk_disable(kp->clk);
> +	clk_put(kp->clk);
> +error3:
> +	iounmap(kp->regs);
> +error2:
> +	release_mem_region(kp->res->start, resource_size(kp->res));
> +error1:
> +	input_free_device(kp->input_dev);
> +error0:
> +	platform_set_drvdata(pdev, NULL);
> +	kfree(kp);
> +	return ret;
> +}
> +
> +static int tnetv107x_keypad_remove(struct platform_device *pdev)
> +{
> +	struct keypad_data *kp = dev_get_drvdata(&pdev->dev);

platform_get_drvdata();

> +
> +	if (kp) {

How kp can be NULL here?

> +		input_unregister_device(kp->input_dev);
> +		free_irq(kp->irq_release, kp);
> +		free_irq(kp->irq_press, kp);
> +		clk_disable(kp->clk);
> +		clk_put(kp->clk);
> +		iounmap(kp->regs);
> +		release_mem_region(kp->res->start, resource_size(kp->res));
> +		input_free_device(kp->input_dev);

No free after unregister.

> +		platform_set_drvdata(pdev, NULL);
> +		kfree(kp);
> +	}
> +	return 0;
> +}
> +
> +static int tnetv107x_keypad_suspend(struct platform_device *pdev,
> +		pm_message_t state)
> +{
> +	/* Nothing yet */
> +	return 0;
> +}
> +
> +static int tnetv107x_keypad_resume(struct platform_device *pdev)
> +{
> +	/* Nothing yet */
> +	return 0;
> +}

If there is nothing yet - drop them.

> +
> +static struct platform_driver tnetv107x_keypad_driver = {
> +	.probe		= tnetv107x_keypad_probe,
> +	.remove		= tnetv107x_keypad_remove,
> +	.suspend	= tnetv107x_keypad_suspend,
> +	.resume		= tnetv107x_keypad_resume,
> +	.driver.name	= "tnetv107x-keypad",

Please assign .owner = THIS_MODULE as well.

> +};
> +
> +static int __init tnetv107x_keypad_init(void)
> +{
> +	return platform_driver_register(&tnetv107x_keypad_driver);
> +}
> +
> +static void __exit tnetv107x_keypad_exit(void)
> +{
> +	platform_driver_unregister(&tnetv107x_keypad_driver);
> +}
> +
> +module_init(tnetv107x_keypad_init);
> +module_exit(tnetv107x_keypad_exit);
> +
> +MODULE_AUTHOR("Cyril Chemparathy");
> +MODULE_DESCRIPTION("TNETV107X Keypad Driver");
> +MODULE_LICENSE("GPL");


MODULE_ALIAS("platform: tnetv107x-keypad"); in case driver gets renamed.

Thanks.

-- 
Dmitry