Hi Alberto,
On Fri, Jan 29, 2010 at 10:18:46PM +0100, Alberto Panizzo wrote:
> +
> +/* mxc_keypad_check_for_events is the timer handler.
> + * It is executed in a non interruptible area of the kernel (Soft interrupt) */
> +static void mxc_keypad_check_for_events(unsigned long data)
> +{
> + struct mxc_keypad *keypad = (struct mxc_keypad *) data;
> + struct input_dev *input_dev = keypad->input_dev;
> + unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
> + unsigned short reg_val;
> + bool state_changed, is_zero_matrix;
> + int i;
> +
> + memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));
> +
> + /* Before exit fire key release events. */
> + if (keypad->exit_flag) {
> + dev_dbg(&input_dev->dev, "%s: exiting.\n", __func__);
> + mxc_keypad_fire_events(keypad, matrix_volatile_state);
Input core already does it no device disconnect, no need to do this
here I think.
> + return;
> + }
> +
> + mxc_keypad_scan_matrix(keypad, matrix_volatile_state);
> +
> + state_changed = false;
> + for (i = 0; (i < MAX_MATRIX_KEY_COLS) && !state_changed; i++) {
> + if ((keypad->cols_en_mask & (1 << i)) == 0)
> + continue;
> +
> + if (keypad->matrix_unstable_state[i] ^
> + matrix_volatile_state[i])
> + state_changed = true;
> + }
> +
> + /* If the matrix state is changed from the previous scan
> + * (Re)Begin the debouncing process, saving the new state in
> + * keypad->matrix_unstable_state.
> + * else
> + * Increase the count of number of scans with a stable state.*/
> + if (state_changed) {
> + memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
> + sizeof(matrix_volatile_state));
> + keypad->stable_count = 0;
> + } else
> + keypad->stable_count++;
> +
> + /* If the matrix is not as stable as we want reschedule a matrix scan
> + * near in the future. */
> + if (keypad->stable_count < MXC_KEYPAD_SCANS_FOR_STABILITY) {
> + mod_timer(&keypad->check_matrix_timer,
> + jiffies + msecs_to_jiffies(2));
2ms is too fast IMO; 10 ms is more realistic.
> + return;
> + }
> +
> + /* If the matrix is stable as we need, fire the events and save the new
> + * stable state.
> + * Note, if the matrix is more stable (keypad->stable_count >
> + * MXC_KEYPAD_SCANS_FOR_STABILITY)all events are already fired.We are in
> + * the loop of multiple key pressure detection waiting for a change. */
> + if (keypad->stable_count == MXC_KEYPAD_SCANS_FOR_STABILITY) {
> + mxc_keypad_fire_events(keypad, matrix_volatile_state);
> +
> + memcpy(keypad->matrix_stable_state, matrix_volatile_state,
> + sizeof(matrix_volatile_state));
> + }
> +
> + is_zero_matrix = true;
> + for (i = 0; (i < MAX_MATRIX_KEY_COLS) && is_zero_matrix; i++)
> + if (matrix_volatile_state[i] != 0)
> + is_zero_matrix = false;
> +
> +
> + if (is_zero_matrix) {
> + /* No keys are still pressed.
> + * Enable only the KDI interrupt for future key pressures.
> + * (clear the KDI status bit and his sync chain before) */
> + reg_val = readw(keypad->mmio_base + KPSR);
> + reg_val |= KBD_STAT_KPKD | KBD_STAT_KDSC;
> + writew(reg_val, keypad->mmio_base + KPSR);
> +
> + reg_val = readw(keypad->mmio_base + KPSR);
> + reg_val |= KBD_STAT_KDIE;
> + reg_val &= ~KBD_STAT_KRIE;
> + writew(reg_val, keypad->mmio_base + KPSR);
> + } else {
> + /* Still there are keys pressed. Schedule a rescan for multiple
> + * key pressure detection and enable the KRI interrupt for fast
> + * reaction to an all key release event. */
> + mod_timer(&keypad->check_matrix_timer,
> + jiffies + msecs_to_jiffies(60));
> +
> + reg_val = readw(keypad->mmio_base + KPSR);
> + reg_val |= KBD_STAT_KPKR | KBD_STAT_KRSS;
> + writew(reg_val, keypad->mmio_base + KPSR);
> +
> + reg_val = readw(keypad->mmio_base + KPSR);
> + reg_val |= KBD_STAT_KRIE;
> + reg_val &= ~KBD_STAT_KDIE;
> + writew(reg_val, keypad->mmio_base + KPSR);
> + }
> +}
> +
> +static irqreturn_t mxc_keypad_irq_handler(int irq, void *dev_id)
> +{
> + struct mxc_keypad *keypad = dev_id;
> + unsigned short reg_val;
> +
> + reg_val = readw(keypad->mmio_base + KPSR);
> +
> + /* Disable every keypad interrupt */
> + reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
> + /* Clear interrupts status bits */
> + reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD;
> + writew(reg_val, keypad->mmio_base + KPSR);
> +
> + /* The matrix is supposed to be changed */
> + keypad->stable_count = 0;
> +
> + /* Schedule the scanning procedure near in the future */
> + mod_timer(&keypad->check_matrix_timer, jiffies + msecs_to_jiffies(2));
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void mxc_keypad_config(struct mxc_keypad *keypad)
> +{
> + unsigned short reg_val;
> +
> + /* Include enabled rows in interrupt generation (KPCR[7:0])
> + * Configure keypad columns as open-drain (KPCR[15:8]) */
> + reg_val = readw(keypad->mmio_base + KPCR);
> + reg_val |= keypad->rows_en_mask & 0xff; /* rows */
> + reg_val |= (keypad->cols_en_mask & 0xff) << 8; /* cols */
> + writew(reg_val, keypad->mmio_base + KPCR);
> +
> + /* Write 0's to KPDR[15:8] (Colums)*/
> + reg_val = readw(keypad->mmio_base + KPDR);
> + reg_val &= 0x00ff;
> + writew(reg_val, keypad->mmio_base + KPDR);
> +
> + /* Configure columns as output, rows as input (KDDR[15:0]) */
> + writew(0xff00, keypad->mmio_base + KDDR);
> +
> + /* Clear Key Depress and Key Release status bit.
> + * Clear both synchronizer chain. */
> + reg_val = readw(keypad->mmio_base + KPSR);
> + reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD |
> + KBD_STAT_KDSC | KBD_STAT_KRSS;
> + writew(reg_val, keypad->mmio_base + KPSR);
> +
> + /* Enable KDI and disable KRI (avoid false release events). */
> + reg_val |= KBD_STAT_KDIE;
> + reg_val &= ~KBD_STAT_KRIE;
> + writew(reg_val, keypad->mmio_base + KPSR);
> +}
> +
> +static void mxc_keypad_inhibit(struct mxc_keypad *keypad)
> +{
> + unsigned short reg_val;
> +
> + /* Inhibit KDI and KRI interrupts. */
> + reg_val = readw(keypad->mmio_base + KPSR);
> + reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
> + writew(reg_val, keypad->mmio_base + KPSR);
> +
> + /* Colums as open drain and disable all rows */
> + writew(0xff00, keypad->mmio_base + KPCR);
> +}
> +
> +static int mxc_keypad_open(struct input_dev *dev)
> +{
> + struct mxc_keypad *keypad = input_get_drvdata(dev);
> +
> + dev_dbg(&dev->dev, ">%s\n", __func__);
> +
> + /* Init Keypad timer */
> + init_timer(&keypad->check_matrix_timer);
> + keypad->check_matrix_timer.function = mxc_keypad_check_for_events;
> + keypad->check_matrix_timer.data = (unsigned long) keypad;
setup_timer(). You also need to do "keypad->exit_flag = false;" here,
otherwise you will not be able to open the device again.
> +
> + /* Enable the kpp clock */
> + clk_enable(keypad->clk);
> + mxc_keypad_config(keypad);
> +
> + /* Sanity control, not all the rows must be actived now. */
> + if ((readw(keypad->mmio_base + KPDR) & keypad->rows_en_mask) == 0) {
> + dev_err(&dev->dev,
> + "too much keys pressed for now, control pins initialisation\n");
> + goto open_err;
> + }
> +
> + return 0;
> +
> +open_err:
> + keypad->exit_flag = true;
> + del_timer_sync(&keypad->check_matrix_timer);
> + mxc_keypad_inhibit(keypad);
> + return -EIO;
> +}
> +
> +static void mxc_keypad_close(struct input_dev *dev)
> +{
> + struct mxc_keypad *keypad = input_get_drvdata(dev);
> +
> + dev_dbg(&dev->dev, ">%s\n", __func__);
> +
> + /* Make sure no checks are pending and release any events.*/
> + keypad->exit_flag = true;
> + del_timer_sync(&keypad->check_matrix_timer);
> + mxc_keypad_check_for_events((unsigned long) keypad);
Why bother with checking for events? The device is being closed - nobody
is in terested in the events since nobody is listening.
> +
> + mxc_keypad_inhibit(keypad);
> +
> + /* Disable clock unit */
> + clk_disable(keypad->clk);
> +}
> +
> +static int __devinit mxc_keypad_probe(struct platform_device *pdev)
> +{
> + const struct matrix_keymap_data *keymap_data = pdev->dev.platform_data;
> + struct mxc_keypad *keypad;
> + struct input_dev *input_dev;
> + struct resource *res;
> + int irq, error, i;
> +
> + if (keymap_data == NULL) {
> + dev_err(&pdev->dev, "no keymap defined\n");
> + return -EINVAL;
> + }
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "no irq defined in platform data\n");
> + return -EINVAL;
> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (res == NULL) {
> + dev_err(&pdev->dev, "no I/O memory defined in platform data\n");
> + return -EINVAL;
> + }
> +
> + res = request_mem_region(res->start, resource_size(res), pdev->name);
> + if (res == NULL) {
> + dev_err(&pdev->dev, "failed to request I/O memory\n");
> + return -EBUSY;
> + }
> +
> + input_dev = input_allocate_device();
> + if (!input_dev) {
> + dev_err(&pdev->dev, "failed to allocate the input device\n");
> + error = -ENOMEM;
> + goto failed_rel_mem;
> + }
> +
> + keypad = kzalloc(sizeof(struct mxc_keypad), GFP_KERNEL);
> + if (!keypad) {
> + dev_err(&pdev->dev, "not enough memory for driver data\n");
> + error = -ENOMEM;
> + goto failed_free_input;
> + }
> +
> + keypad->input_dev = input_dev;
> + keypad->irq = irq;
> + keypad->stable_count = 0;
> + keypad->exit_flag = false;
> +
> + keypad->mmio_base = ioremap(res->start, resource_size(res));
> + if (keypad->mmio_base == NULL) {
> + dev_err(&pdev->dev, "failed to remap I/O memory\n");
> + error = -ENOMEM;
> + goto failed_free_priv;
> + }
> +
> + keypad->clk = clk_get(&pdev->dev, "kpp");
> + if (IS_ERR(keypad->clk)) {
> + dev_err(&pdev->dev, "failed to get keypad clock\n");
> + error = PTR_ERR(keypad->clk);
> + goto failed_unmap;
> + }
> +
> + /* Search for rows and cols enabled */
> + for (i = 0; i < keymap_data->keymap_size; i++) {
> + keypad->rows_en_mask |= 1 << KEY_ROW(keymap_data->keymap[i]);
> + keypad->cols_en_mask |= 1 << KEY_COL(keymap_data->keymap[i]);
> + }
> +
> + if (keypad->rows_en_mask > ((1 << MAX_MATRIX_KEY_ROWS) - 1) ||
> + keypad->cols_en_mask > ((1 << MAX_MATRIX_KEY_COLS) - 1)) {
> + dev_err(&pdev->dev, "invalid key data (too rows or colums)\n");
> + error = -EINVAL;
> + goto failed_clock_put;
> + }
> + dev_dbg(&pdev->dev, "enabled rows mask: %x\n", keypad->rows_en_mask);
> + dev_dbg(&pdev->dev, "enabled cols mask: %x\n", keypad->cols_en_mask);
> +
> + /* Init the Input device */
> + input_dev->name = pdev->name;
> + input_dev->id.bustype = BUS_HOST;
> + input_dev->dev.parent = &pdev->dev;
> + input_dev->open = mxc_keypad_open;
> + input_dev->close = mxc_keypad_close;
> + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
> + input_dev->keycode = keypad->keycodes;
> + input_dev->keycodesize = sizeof(keypad->keycodes[0]);
> + input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
> +
> + matrix_keypad_build_keymap(keymap_data, MATRIX_ROW_SHIFT,
> + keypad->keycodes, input_dev->keybit);
> +
> + input_set_capability(input_dev, EV_MSC, MSC_SCAN);
> + input_set_drvdata(input_dev, keypad);
> +
I would feell more safe if we also called inhibit here. I there any
chance that matrix can gerenrate interrupts at this point? If it can and
we never call open/close then in remove there is a chace of freeing
input device before freeing IRQ.
> + error = request_irq(irq, mxc_keypad_irq_handler, IRQF_DISABLED,
> + pdev->name, keypad);
> + if (error) {
> + dev_err(&pdev->dev, "failed to request IRQ\n");
> + goto failed_clock_put;
> + }
> +
> + /* Register the input device */
> + error = input_register_device(input_dev);
> + if (error) {
> + dev_err(&pdev->dev, "failed to register input device\n");
> + goto failed_free_irq;
> + }
> +
> + platform_set_drvdata(pdev, keypad);
> + device_init_wakeup(&pdev->dev, 1);
> +
> + dev_info(&pdev->dev, "device probed\n");
> +
> + return 0;
> +
> +failed_free_irq:
> + free_irq(irq, pdev);
> +failed_clock_put:
> + clk_put(keypad->clk);
> +failed_unmap:
> + iounmap(keypad->mmio_base);
> +failed_free_priv:
> + kfree(keypad);
> +failed_free_input:
> + input_free_device(input_dev);
> +failed_rel_mem:
> + release_mem_region(res->start, resource_size(res));
> + return error;
> +}
> +
> +static int __devexit mxc_keypad_remove(struct platform_device *pdev)
> +{
> + struct mxc_keypad *keypad = platform_get_drvdata(pdev);
> + struct resource *res;
> +
> + dev_dbg(&pdev->dev, ">%s\n", __func__);
> +
> + platform_set_drvdata(pdev, NULL);
> +
> + input_unregister_device(keypad->input_dev);
> +
> + free_irq(keypad->irq, keypad);
> + clk_put(keypad->clk);
> +
> + iounmap(keypad->mmio_base);
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + release_mem_region(res->start, resource_size(res));
> +
> + kfree(keypad);
> +
> + dev_info(&pdev->dev, "device removed\n");
> +
> + return 0;
> +}
> +
> +static struct platform_driver mxc_keypad_driver = {
> + .driver = {
> + .name = "mxc-keypad",
> + .owner = THIS_MODULE,
> + },
> + .probe = mxc_keypad_probe,
> + .remove = __devexit_p(mxc_keypad_remove),
> +};
> +
> +static int __init mxc_keypad_init(void)
> +{
> + return platform_driver_register(&mxc_keypad_driver);
> +}
> +
> +static void __exit mxc_keypad_exit(void)
> +{
> + platform_driver_unregister(&mxc_keypad_driver);
> +}
> +
> +module_init(mxc_keypad_init);
> +module_exit(mxc_keypad_exit);
> +
> +MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@xxxxxxxxx>");
> +MODULE_DESCRIPTION("MXC Keypad Port Driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:mxc-keypad");
> --
> 1.6.3.3
>
>
>
--
Dmitry
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