Re: [PATCH v3 1/1] input: add support for Nomadik SKE keypad controller

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

Hi Sundar,

On Mon, Sep 06, 2010 at 06:18:04PM +0530, Sundar Iyer wrote:
> Acked-by: Linus Walleij <linus.walleij@stericsson.com>
> Signed-off-by: Sundar Iyer <sundar.iyer@stericsson.com>
> ---
> 
> Changes:
> v3:
>  - fixed Dmitry's comments assorted comments,
>  - re-orged the IRQ to include a timer instead of cpu_relax()
> 

Thank you for making the changes.

>  arch/arm/plat-nomadik/include/plat/ske.h    |   54 ++++
>  drivers/input/keyboard/Kconfig              |   10 +
>  drivers/input/keyboard/Makefile             |    1 +
>  drivers/input/keyboard/nomadik-ske-keypad.c |  449 +++++++++++++++++++++++++++
>  4 files changed, 514 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/plat-nomadik/include/plat/ske.h
>  create mode 100644 drivers/input/keyboard/nomadik-ske-keypad.c
> 
> diff --git a/arch/arm/plat-nomadik/include/plat/ske.h b/arch/arm/plat-nomadik/include/plat/ske.h
> new file mode 100644
> index 0000000..27aeadb
> --- /dev/null
> +++ b/arch/arm/plat-nomadik/include/plat/ske.h
> @@ -0,0 +1,54 @@
> +/*
> + * Copyright (C) ST-Ericsson SA 2010
> + *
> + * License Terms: GNU General Public License v2
> + * Author: Naveen Kumar Gaddipati <naveen.gaddipati@stericsson.com>
> + *
> + * ux500 Scroll key and Keypad Encoder (SKE) header
> + */
> +
> +#ifndef __SKE_H
> +#define __SKE_H
> +
> +#include <linux/input/matrix_keypad.h>
> +
> +/* register definitions for SKE peripheral */
> +#define SKE_CR		0x00
> +#define SKE_VAL0	0x04
> +#define SKE_VAL1	0x08
> +#define SKE_DBCR	0x0C
> +#define SKE_IMSC	0x10
> +#define SKE_RIS		0x14
> +#define SKE_MIS		0x18
> +#define SKE_ICR		0x1C
> +#define SKE_ASR0	0x20
> +#define SKE_ASR1	0x24
> +#define SKE_ASR2	0x28
> +#define SKE_ASR3	0x2C
> +
> +#define SKE_NUM_ASRX_REGISTERS	(4)
> +
> +/*
> + * Keypad module
> + */
> +
> +/**
> + * struct keypad_platform_data - structure for platform specific data
> + * @init:	pointer to keypad init function
> + * @exit:	pointer to keypad deinitialisation function
> + * @keymap_data: matrix scan code table for keycodes
> + * @krow:	maximum number of rows
> + * @kcol:	maximum number of columns
> + * @debounce_ms: platform specific debounce time
> + * @no_autorepeat: flag for auto repetition
> + */
> +struct ske_keypad_platform_data {
> +	int (*init)(void);
> +	int (*exit)(void);
> +	struct matrix_keymap_data *keymap_data;

const please.

> +	u8 krow;
> +	u8 kcol;
> +	u8 debounce_ms;
> +	bool no_autorepeat;
> +};
> +#endif	/*__SKE_KPD_H*/
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index 4f30048..d63f566 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -327,6 +327,16 @@ config KEYBOARD_NEWTON
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called newtonkbd.
>  
> +config KEYBOARD_NOMADIK
> +	tristate "ST-Ericsson Nomadik SKE keyboard"
> +	depends on PLAT_NOMADIK
> +	help
> +	  Say Y here if you want to use a keypad provided on the SKE controller
> +	  used on the Ux500 and Nomadik platforms
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called nmk-ske-keypad.
> +
>  config KEYBOARD_OPENCORES
>  	tristate "OpenCores Keyboard Controller"
>  	help
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index 8ac01fb..c13809c 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
>  obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
>  obj-$(CONFIG_KEYBOARD_MCS)		+= mcs_touchkey.o
>  obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
> +obj-$(CONFIG_KEYBOARD_NOMADIK)		+= nomadik-ske-keypad.o
>  obj-$(CONFIG_KEYBOARD_OMAP)		+= omap-keypad.o
>  obj-$(CONFIG_KEYBOARD_OMAP4)		+= omap4-keypad.o
>  obj-$(CONFIG_KEYBOARD_OPENCORES)	+= opencores-kbd.o
> diff --git a/drivers/input/keyboard/nomadik-ske-keypad.c b/drivers/input/keyboard/nomadik-ske-keypad.c
> new file mode 100644
> index 0000000..1697181
> --- /dev/null
> +++ b/drivers/input/keyboard/nomadik-ske-keypad.c
> @@ -0,0 +1,449 @@
> +/*
> + * Copyright (C) ST-Ericsson SA 2010
> + *
> + * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
> + * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
> + *
> + * License terms:GNU General Public License (GPL) version 2
> + *
> + * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
> + * the Nomadik 8815 and Ux500 platforms.
> + */
> +
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <linux/spinlock.h>
> +#include <linux/io.h>
> +#include <linux/input.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +
> +#include <plat/ske.h>
> +
> +/* SKE_CR bits */
> +#define SKE_KPMLT	(0x1 << 6)
> +#define SKE_KPCN	(0x7 << 3)
> +#define SKE_KPASEN	(0x1 << 2)
> +#define SKE_KPASON	(0x1 << 7)
> +
> +/* SKE_IMSC bits */
> +#define SKE_KPIMA	(0x1 << 2)
> +
> +/* SKE_ICR bits */
> +#define SKE_KPICS	(0x1 << 3)
> +#define SKE_KPICA	(0x1 << 2)
> +
> +/* SKE_RIS bits */
> +#define SKE_KPRISA	(0x1 << 2)
> +
> +#define SKE_KEYPAD_ROW_SHIFT	3
> +#define SKE_KPD_KEYMAP_SIZE	(8 * 8)
> +
> +/**
> + * struct ske_keypad  - data structure used by keypad driver
> + * @irq:	irq no
> + * @reg_base:	ske regsiters base address
> + * @input:	pointer to input device object
> + * @board:	keypad platform device
> + * @keymap:	matrix scan code table for keycodes
> + * @clk:	clock structure pointer
> + */
> +struct ske_keypad {
> +	int irq;
> +	void __iomem *reg_base;
> +	struct input_dev *input;
> +	const struct ske_keypad_platform_data *board;
> +	unsigned short keymap[SKE_KPD_KEYMAP_SIZE];
> +	struct clk *clk;
> +	spinlock_t ske_keypad_lock;
> +	struct timer_list timer;
> +};
> +
> +static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
> +		u8 mask, u8 data)
> +{
> +	u32 ret;
> +
> +	spin_lock(&keypad->ske_keypad_lock);
> +
> +	ret = readl(keypad->reg_base + addr);
> +	ret &= ~mask;
> +	ret |= data;
> +	writel(ret, keypad->reg_base + addr);
> +
> +	spin_unlock(&keypad->ske_keypad_lock);
> +}
> +
> +/*
> + * ske_keypad_chip_init : init keypad controller configuration
> + *
> + * Enable Multi key press detection, auto scan mode
> + */
> +static int __devinit ske_keypad_chip_init(struct ske_keypad *keypad)
> +{
> +	u32 value;
> +	int timeout = keypad->board->debounce_ms;
> +
> +	/* check SKE_RIS to be 0 */
> +	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
> +		cpu_relax();
> +	if (!timeout)
> +		return -EINVAL;
> +
> +	/*
> +	 * set debounce value
> +	 * keypad dbounce is configured in DBCR[15:8]
> +	 * dbounce value in steps of 32/32.768 ms
> +	 */
> +	spin_lock(&keypad->ske_keypad_lock);
> +	value = readl(keypad->reg_base + SKE_DBCR);
> +	value = value & 0xff;
> +	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
> +	writel(value, keypad->reg_base + SKE_DBCR);
> +	spin_unlock(&keypad->ske_keypad_lock);
> +
> +	/* enable multi key detection */
> +	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
> +
> +	/*
> +	 * set up the number of columns
> +	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
> +	 */
> +	value = (keypad->board->kcol - 1) << 3;
> +	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
> +
> +	/* clear keypad interrupt for auto(and pending SW) scans */
> +	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
> +
> +	/* un-mask keypad interrupts */
> +	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
> +
> +	/* enable automatic scan */
> +	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
> +
> +	return 0;
> +}
> +
> +static void ske_keypad_read_data(struct ske_keypad *keypad)
> +{
> +	struct input_dev *input = keypad->input;
> +	u16 status;
> +	int col = 0, row = 0, code;
> +	int ske_asr, ske_ris, key_pressed, i;
> +
> +	/*
> +	 * Read the auto scan registers
> +	 *
> +	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
> +	 * lower byte contains row value for coloumn 2*x,
> +	 * upper byte contains row value for column 2*x + 1
> +	 */
> +	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
> +		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
> +		if (!ske_asr)
> +			continue;
> +
> +		/* now that ASRx is zero, find out the coloumn x and row y*/
> +		if (ske_asr & 0xff) {
> +			col = i * 2;
> +			status = ske_asr & 0xff;
> +		} else {
> +			col = (i * 2) + 1;
> +			status = (ske_asr & 0xff00) >> 8;
> +		}
> +
> +		/* find out the row */
> +		row = __ffs(status);
> +
> +		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
> +		ske_ris = readl(keypad->reg_base + SKE_RIS);
> +		key_pressed = ske_ris & SKE_KPRISA;
> +
> +		input_event(input, EV_MSC, MSC_SCAN, code);
> +		input_report_key(input, keypad->keymap[code], key_pressed);
> +		input_sync(input);
> +	}
> +	return;

No naked returns at the end of void functions please.

> +}
> +
> +static void ske_keypad_timer(unsigned long data)
> +{
> +	struct platform_device *pdev =  (struct platform_device *) data;
> +	struct ske_keypad *keypad = platform_get_drvdata(pdev);
> +	int ske_kpason;
> +	int timeout = keypad->board->debounce_ms;
> +
> +	ske_kpason = readl(keypad->reg_base + SKE_CR) & SKE_KPASON;
> +	if (ske_kpason) {
> +		mod_timer(&keypad->timer, jiffies + msecs_to_jiffies(timeout));
> +		return;
> +	}
> +
> +	/* read data registers and report event */
> +	ske_keypad_read_data(keypad);
> +
> +	return;
> +}
> +
> +static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
> +{
> +	struct ske_keypad *keypad = dev_id;
> +	int timeout = keypad->board->debounce_ms;
> +
> +	/* disable auto scan interrupt; mask the interrupt generated */
> +	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
> +	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
> +
> +	/*
> +	 * if KPASON is not ready, we cannot read data registers
> +	 * so wait for a debounce period; if still not settled,
> +	 * we fire a timer and exit the IRQ
> +	 */
> +	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && timeout--)
> +		cpu_relax();
> +	if (!timeout) {
> +		mod_timer(&keypad->timer, jiffies + msecs_to_jiffies(timeout));

timeout is 0 here, I do not think that's what you want.

> +		goto out;
> +	}
> +
> +	/*
> +	 * KPASON behaved nicely and we can read data registers and report event
> +	 */
> +	ske_keypad_read_data(keypad);
> +
> +out:
> +	/* enable auto scan interrupts */
> +	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

You sure you want do do it here even when SKE_KPASON is set and timer is
pending? I'd expect re-enabling interrupts from the timer.

> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int __devinit ske_keypad_probe(struct platform_device *pdev)
> +{
> +	struct ske_keypad *keypad;
> +	struct resource *res;
> +	struct input_dev *input;
> +	struct clk *clk;
> +	void __iomem *reg_base;
> +	int ret;
> +	int irq;
> +	const struct ske_keypad_platform_data *plat = pdev->dev.platform_data;
> +
> +	if (!plat) {
> +		dev_err(&pdev->dev, "invalid keypad platform data\n");
> +		ret = -EINVAL;
> +		goto out_ret;
> +	}
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(&pdev->dev, "failed to get keypad irq\n");
> +		ret = -EINVAL;
> +		goto out_ret;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (res == NULL) {
> +		dev_err(&pdev->dev, "missing platform resources\n");
> +		ret = -EINVAL;
> +		goto out_ret;
> +	}
> +
> +	res = request_mem_region(res->start, resource_size(res), pdev->name);
> +	if (!res) {
> +		dev_err(&pdev->dev, "failed to request I/O memory\n");
> +		ret = -EBUSY;
> +		goto out_ret;
> +	}
> +
> +	reg_base = ioremap(res->start, resource_size(res));
> +	if (!reg_base) {
> +		dev_err(&pdev->dev, "failed to remap I/O memory\n");
> +		ret = -ENXIO;
> +		goto out_freerequest_memregions;
> +	}
> +
> +	clk = clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(clk)) {
> +		dev_err(&pdev->dev, "failed to clk_get\n");
> +		ret = PTR_ERR(clk);
> +		goto out_freeioremap;
> +	}
> +
> +	/* resources are sane; we begin allocation */
> +	keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
> +	if (!keypad) {
> +		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
> +		ret = -ENOMEM;
> +		goto out_freeclk;
> +	}
> +
> +	input = input_allocate_device();
> +	if (!input) {
> +		dev_err(&pdev->dev, "failed to input_allocate_device\n");
> +		ret = -ENOMEM;
> +		goto out_freekeypad;
> +	}
> +
> +	input->id.bustype = BUS_HOST;
> +	input->name = "ux500-ske-keypad";
> +	input->dev.parent = &pdev->dev;
> +
> +	input->keycode = keypad->keymap;
> +	input->keycodesize = sizeof(keypad->keymap[0]);
> +	input->keycodemax = ARRAY_SIZE(keypad->keymap);
> +
> +	input_set_capability(input, EV_MSC, MSC_SCAN);
> +
> +	__set_bit(EV_KEY, input->evbit);
> +	if (!plat->no_autorepeat)
> +		__set_bit(EV_REP, input->evbit);
> +
> +	matrix_keypad_build_keymap(plat->keymap_data, SKE_KEYPAD_ROW_SHIFT,
> +					input->keycode, input->keybit);
> +
> +	ret = input_register_device(input);
> +	if (ret) {
> +		dev_err(&pdev->dev,
> +			"unable to register input device: %d\n", ret);
> +		goto out_freeinput;
> +	}

I'd probably move registration past requesting IRQ - it will simplify
error handling I think. It is safe to send events through input device
as long as it has been allocated with input_allocate_device() even if it
has not been registered yet.

> +
> +	keypad->irq	= irq;
> +	keypad->board	= plat;
> +	keypad->input	= input;
> +	keypad->reg_base = reg_base;
> +	keypad->clk	= clk;
> +
> +	/* allocations are sane, we begin HW initialization */
> +	clk_enable(keypad->clk);
> +
> +	/* go through board initialiazation helpers */
> +	if (keypad->board->init) {
> +		keypad->board->init();

I do not think you actually compiled this - closing brace is missing
(well, braces are actually not needed at all).

> +
> +	ret = ske_keypad_chip_init(keypad);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "unable to init keypad hardware\n");
> +		goto out_unregisterinput;
> +	}
> +
> +	spin_lock_init(&keypad->ske_keypad_lock);
> +	setup_timer(&keypad->timer, ske_keypad_timer, (unsigned long)pdev);
> +
> +	ret =  request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
> +				IRQF_ONESHOT, "ske-keypad", keypad);
> +	if (ret) {
> +		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
> +		goto out_unregisterinput;
> +	}
> +
> +	device_init_wakeup(&pdev->dev, true);
> +
> +	platform_set_drvdata(pdev, keypad);
> +
> +	return 0;
> +
> +out_unregisterinput:
> +	input_unregister_device(input);
> +	input = NULL;
> +	clk_disable(keypad->clk);
> +out_freeinput:
> +	input_free_device(input);
> +out_freekeypad:
> +	kfree(keypad);
> +out_freeclk:
> +	clk_put(clk);
> +out_freeioremap:
> +	iounmap(reg_base);
> +out_freerequest_memregions:
> +	release_mem_region(res->start, resource_size(res));
> +out_ret:
> +	return ret;
> +}
> +
> +static int __devexit ske_keypad_remove(struct platform_device *pdev)
> +{
> +	struct ske_keypad *keypad = platform_get_drvdata(pdev);
> +	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> +	del_timer_sync(&keypad->timer);
> +	free_irq(keypad->irq, keypad);
> +	input_unregister_device(keypad->input);
> +
> +	clk_disable(keypad->clk);
> +	clk_put(keypad->clk);
> +
> +	if (keypad->board->exit())

You are already aware of the issue here...

> +		keypad->board->exit();
> +
> +	iounmap(keypad->reg_base);
> +	release_mem_region(res->start, resource_size(res));
> +	kfree(keypad);


	platform_set_drvdata(pdev, NULL);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int ske_keypad_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct ske_keypad *keypad = platform_get_drvdata(pdev);
> +	int irq = platform_get_irq(pdev, 0);
> +
> +	if (device_may_wakeup(dev))
> +		enable_irq_wake(irq);
> +	else
> +		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
> +
> +	return 0;
> +}
> +
> +static int ske_keypad_resume(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct ske_keypad *keypad = platform_get_drvdata(pdev);
> +	int irq = platform_get_irq(pdev, 0);
> +
> +	if (device_may_wakeup(dev))
> +		disable_irq_wake(irq);
> +	else
> +		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops ske_keypad_dev_pm_ops = {
> +	.suspend = ske_keypad_suspend,
> +	.resume = ske_keypad_resume,
> +};
> +#endif
> +
> +struct platform_driver ske_keypad_driver = {
> +	.driver = {
> +		.name = "nmk-ske-keypad",
> +		.owner  = THIS_MODULE,
> +#ifdef CONFIG_PM
> +		.pm = &ske_keypad_dev_pm_ops,
> +#endif
> +	},
> +	.probe = ske_keypad_probe,
> +	.remove = __devexit_p(ske_keypad_remove),
> +};
> +
> +static int __init ske_keypad_init(void)
> +{
> +	return platform_driver_probe(&ske_keypad_driver, ske_keypad_probe);
> +}
> +module_init(ske_keypad_init);
> +
> +static void __exit ske_keypad_exit(void)
> +{
> +	platform_driver_unregister(&ske_keypad_driver);
> +}
> +module_exit(ske_keypad_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Naveen Kumar G/Sundar Iyer");
> +MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
> +MODULE_ALIAS("platform:nomadik-ske-keypad");
> -- 
> 1.7.2.dirty
> 

-- 
Dmitry