Re: [PATCH 1/2] [INPUT] Blackfin BF54x Input Keypad controller driver

[Dmitry Torokhov]

Hi Bryan, Michael,

On 9/25/07, Bryan Wu <bryan.wu@xxxxxxxxxx> wrote:
> From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
> Date: Sun, 5 Aug 2007 18:45:26 +0800
> Subject: [PATCH 1/2] [INPUT] Blackfin BF54x Input Keypad controller driver
>

Thank you for the patch. Couple of comments:

> +
> +static void bfin_kpad_timer(unsigned long data)
> +{
> +       struct platform_device *pdev =  (struct platform_device *) data;
> +       struct bf54x_kpad *bf54x_kpad = platform_get_drvdata(pdev);
> +
> +       if (bfin_kpad_get_keypressed(bf54x_kpad)) {
> +               /* Try again later */
> +               mod_timer(&bf54x_kpad->timer, jiffies
> +                               + bf54x_kpad->keyup_test_jiffies);
> +               return;
> +       }
> +
> +       input_report_key(bf54x_kpad->input, bf54x_kpad->lastkey, 0);
> +       input_sync(bf54x_kpad->input);
> +

So it is not possible to press another key without releaseing the first one?

> +       /* Clear IRQ Status */
> +
> +       bfin_kpad_clear_irq();
> +       enable_irq(bf54x_kpad->irq);
> +}
> +
> +static irqreturn_t bfin_kpad_isr(int irq, void *dev_id)
> +{
> +       struct platform_device *pdev = dev_id;
> +       struct bfin_kpad_platform_data *pdata = pdev->dev.platform_data;
> +       struct bf54x_kpad *bf54x_kpad = platform_get_drvdata(pdev);
> +       int key;
> +       u16 rowcol = bfin_read_KPAD_ROWCOL();
> +
> +       key = bfin_kpad_find_key(pdata, rowcol);
> +
> +       input_report_key(bf54x_kpad->input, key, 1);
> +       input_sync(bf54x_kpad->input);
> +
> +       if (bfin_kpad_get_keypressed(bf54x_kpad)) {
> +               disable_irq(bf54x_kpad->irq);
> +               bf54x_kpad->lastkey = key;
> +               bf54x_kpad->timer.expires = jiffies
> +                                       + bf54x_kpad->keyup_test_jiffies;
> +               add_timer(&bf54x_kpad->timer);
> +
> +               return IRQ_HANDLED;
> +       }
> +
> +       input_report_key(bf54x_kpad->input, key, 0);
> +       input_sync(bf54x_kpad->input);
> +
> +       bfin_kpad_clear_irq();
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static int __devinit bfin_kpad_probe(struct platform_device *pdev)
> +{
> +       struct bf54x_kpad *bf54x_kpad;
> +       struct bfin_kpad_platform_data *pdata = pdev->dev.platform_data;
> +       int i, error;
> +
> +
> +       if (!pdata->rows || !pdata->cols || !pdata->keymap) {
> +               printk(KERN_ERR DRV_NAME"No rows, cols or keymap from pdata\n");
> +               return -EINVAL;
> +       }
> +
> +       if (!pdata->keymapsize || pdata->keymapsize > (pdata->rows * pdata->cols)) {
> +               printk(KERN_ERR DRV_NAME"Invalid keymapsize\n");
> +               return -EINVAL;
> +       }
> +
> +       bf54x_kpad = kzalloc(sizeof(struct bf54x_kpad), GFP_KERNEL);
> +
> +       if (!bf54x_kpad) {
> +               return -ENOMEM;
> +       }

Loose extra braces please.

> +
> +       platform_set_drvdata(pdev, bf54x_kpad);
> +
> +
> +       if (!pdata->debounce_time || !pdata->debounce_time > MAX_MULT ||
> +               !pdata->coldrive_time || !pdata->coldrive_time > MAX_MULT) {
> +               printk(KERN_ERR DRV_NAME
> +                       "Invalid Debounce/Columdrive Time from pdata\n");
> +               bfin_write_KPAD_MSEL(0xFF0);    /* Default MSEL */
> +       } else {
> +               bfin_write_KPAD_MSEL(((pdata->debounce_time / TIME_SCALE)
> +                        & DBON_SCALE) | (((pdata->coldrive_time / TIME_SCALE) << 8)
> +                         & COLDRV_SCALE));
> +
> +       }
> +
> +       if (!pdata->keyup_test_interval) {
> +               bf54x_kpad->keyup_test_jiffies = msecs_to_jiffies(50);
> +       } else {
> +               bf54x_kpad->keyup_test_jiffies =
> +                       msecs_to_jiffies(pdata->keyup_test_interval);
> +       }
> +
> +       if (peripheral_request_list(&per_rows[MAX_RC - pdata->rows], DRV_NAME)) {
> +               printk(KERN_ERR DRV_NAME
> +               ": Requesting Peripherals failed\n");
> +               error = -EFAULT;
> +               goto out;
> +       }
> +
> +       if (peripheral_request_list(&per_cols[MAX_RC - pdata->cols], DRV_NAME)) {
> +               printk(KERN_ERR DRV_NAME
> +               ": Requesting Peripherals failed\n");
> +               error = -EFAULT;
> +               goto out1;
> +       }
> +
> +       bf54x_kpad->irq = platform_get_irq(pdev, 0);
> +
> +       if (bf54x_kpad->irq < 0) {
> +               error = -ENODEV;
> +               goto out2;
> +       }
> +
> +       error = request_irq(bf54x_kpad->irq, bfin_kpad_isr,
> +                                IRQF_SAMPLE_RANDOM, DRV_NAME, pdev);
> +
> +       if (error) {
> +               printk(KERN_ERR DRV_NAME
> +                       ": unable to claim irq %d; error %d\n",
> +                       bf54x_kpad->irq, error);
> +               error = -EBUSY;
> +               goto out2;
> +       }
> +

Its it guaranteed that IRQ will not be raised here? Because if it may
then yo need to allocate input device before regitering IRQ handler.

> +
> +       bf54x_kpad->input = input_allocate_device();
> +
> +       if (!bf54x_kpad->input) {
> +               error = -ENOMEM;
> +               goto out3;
> +       }
> +
> +       bf54x_kpad->input->name = pdev->name;
> +       bf54x_kpad->input->phys = "bf54x-keys/input0";
> +       bf54x_kpad->input->cdev.dev = &pdev->dev;
> +       bf54x_kpad->input->private = bf54x_kpad;
> +
> +       bf54x_kpad->input->id.bustype = BUS_HOST;
> +       bf54x_kpad->input->id.vendor = 0x0001;
> +       bf54x_kpad->input->id.product = 0x0001;
> +       bf54x_kpad->input->id.version = 0x0100;

May I recommend using a temp variable for bf54x_kpad->input. It may
reduce size of generated code.

> +
> +       bf54x_kpad->input->keycode = pdata->keymap;

Normally we copy the vanilla keymap to the device structure so if it
gets changed and later driver gets unbound/rebound the new input
device will get a fresh unaffected keymap.

> +       bf54x_kpad->input->keycodesize = sizeof(unsigned int);

unsigned short should cover all our keycodes.

> +       bf54x_kpad->input->keycodemax = pdata->keymapsize;
> +
> +       /* setup input device */
> +       set_bit(EV_KEY, bf54x_kpad->input->evbit);

You might want to add EV_REP to get autorepeat. You don't need
atomicity so you may want to use __set_bit().
> +
> +       for (i = 0; i < pdata->keymapsize; i++)
> +               set_bit(pdata->keymap[i] & KEY_MAX, bf54x_kpad->input->keybit);

__clear_bit(KEY_RESERVED, bf54x_kpad->input->keybit); to make sure we
don't advertise it to the userspace.

> +
> +       error = input_register_device(bf54x_kpad->input);
> +
> +       if (error) {
> +               printk(KERN_ERR DRV_NAME": Unable to register input device\n");

Printing the error code might be a good idea too.

> +               goto out4;
> +       }
> +
> +       /* Init Keypad Key Up/Release test timer */
> +
> +       init_timer(&bf54x_kpad->timer);
> +       bf54x_kpad->timer.function = bfin_kpad_timer;
> +       bf54x_kpad->timer.data = (unsigned long) pdev;
> +
> +
> +       bfin_write_KPAD_PRESCALE(bfin_kpad_get_prescale(TIME_SCALE));
> +
> +       bfin_write_KPAD_CTL((((pdata->cols - 1) << 13) & KPAD_COLEN) |
> +                               (((pdata->rows - 1) << 10) & KPAD_ROWEN) |
> +                               (2 & KPAD_IRQMODE));
> +
> +
> +       bfin_write_KPAD_CTL(bfin_read_KPAD_CTL() | KPAD_EN);
> +
> +       printk(KERN_ERR DRV_NAME
> +               ": Blackfin BF54x Keypad registered IRQ %d\n", bf54x_kpad->irq);
> +
> +       return 0;
> +
> +
> +out4:
> +       input_free_device(bf54x_kpad->input);
> +out3:
> +       free_irq(bf54x_kpad->irq, pdev);
> +out2:
> +       peripheral_free_list(&per_cols[MAX_RC - pdata->cols]);
> +out1:
> +       peripheral_free_list(&per_rows[MAX_RC - pdata->rows]);
> +out:
> +       kfree(bf54x_kpad);
> +

Please add platform_set_devdata(pdev, NULL); so we don;t leave dirty
pointers around.

> +       return error;
> +}
> +
> +static int __devexit bfin_kpad_remove(struct platform_device *pdev)
> +{
> +       struct bfin_kpad_platform_data *pdata = pdev->dev.platform_data;
> +       struct bf54x_kpad *bf54x_kpad = platform_get_drvdata(pdev);
> +
> +
> +       del_timer_sync(&bf54x_kpad->timer);
> +       free_irq(bf54x_kpad->irq, pdev);

Same here.

> +
> +       peripheral_free_list(&per_rows[MAX_RC - pdata->rows]);
> +       peripheral_free_list(&per_cols[MAX_RC - pdata->cols]);
> +
> +       input_unregister_device(bf54x_kpad->input);
> +
> +       kfree(bf54x_kpad);
> +
> +       return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int bfin_kpad_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +       return 0;

Hmm.. I'd t least stopped timer here.

> +}
> +
> +static int bfin_kpad_resume(struct platform_device *pdev)
> +{
> +
> +       return 0;
> +}
> +#else
> +#define bfin_kpad_suspend      NULL
> +#define bfin_kpad_resume       NULL
> +#endif
> +
> +struct platform_driver bfin_kpad_device_driver = {
> +       .probe          = bfin_kpad_probe,
> +       .remove         = __devexit_p(bfin_kpad_remove),
> +       .suspend        = bfin_kpad_suspend,
> +       .resume         = bfin_kpad_resume,
> +       .driver         = {
> +               .name   = DRV_NAME,
> +       }
> +};
> +
> +static int __init bfin_kpad_init(void)
> +{
> +       return platform_driver_register(&bfin_kpad_device_driver);
> +}
> +
> +static void __exit bfin_kpad_exit(void)
> +{
> +       platform_driver_unregister(&bfin_kpad_device_driver);
> +}
> +
> +module_init(bfin_kpad_init);
> +module_exit(bfin_kpad_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Michael Hennerich <hennerich@xxxxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Keypad driver for BF54x Processors");
> diff --git a/include/asm-blackfin/mach-bf548/bf54x_keys.h b/include/asm-blackfin/mach-bf548/bf54x_keys.h
> new file mode 100644
> index 0000000..e7e1352
> --- /dev/null
> +++ b/include/asm-blackfin/mach-bf548/bf54x_keys.h
> @@ -0,0 +1,18 @@
> +#ifndef _BFIN_KPAD_H
> +#define _BFIN_KPAD_H
> +
> +#include <linux/input.h>

This include is not needed here.

> +
> +struct bfin_kpad_platform_data {
> +       int rows;
> +       int cols;
> +       int *keymap;
> +       unsigned int keymapsize;
> +       u32 debounce_time;      /* in ns */
> +       u32 coldrive_time;      /* in ns */
> +       u32 keyup_test_interval; /* in ms */
> +};
> +
> +#define KEYVAL(col, row, val) (((1 << col) << 24) | ((1 << row) << 16) | (val))
> +
> +#endif

Thank you.

-- 
Dmitry
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