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

["Datta, Shubhrajyoti" <shubhrajyoti@ti.com>]

Hi Sundar,
> -----Original Message-----
> From: linux-input-owner@vger.kernel.org [mailto:linux-input-
> owner@vger.kernel.org] On Behalf Of Sundar Iyer
> Sent: Monday, September 06, 2010 6:18 PM
> To: dmitry.torokhov@gmail.com
> Cc: linux-input@vger.kernel.org; STEricsson_nomadik_linux@list.st.com;
> Sundar Iyer; Linus Walleij
> Subject: [PATCH v3 1/1] input: add support for Nomadik SKE keypad
> controller
>
> 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()
>
>  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;
> +     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;
> +}
> +
> +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));
> +             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);
> +
> +     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;
> +     }
> +
> +     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) {
Did not understand this

> +             keypad->board->init();
> +
> +     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())
> +             keypad->board->exit();

        if (keypad->board->exit)
                keypad->board->exit();
What does this exit function do?
Are you sure the exit function does not need the keypad clock?

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