From patchwork Wed Jan 6 12:58:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 357796 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 776BEC433E9 for ; Wed, 6 Jan 2021 12:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B0DF2312C for ; Wed, 6 Jan 2021 12:59:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727261AbhAFM7S (ORCPT ); Wed, 6 Jan 2021 07:59:18 -0500 Received: from muru.com ([72.249.23.125]:41010 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727246AbhAFM7S (ORCPT ); Wed, 6 Jan 2021 07:59:18 -0500 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id C88D98158; Wed, 6 Jan 2021 12:58:56 +0000 (UTC) From: Tony Lindgren To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Arthur Demchenkov , Carl Philipp Klemm , Merlijn Wajer , Pavel Machek , ruleh , Sebastian Reichel Subject: [PATCH 2/4] Input: omap4-keypad - scan keys in two phases and simplify with bitmask Date: Wed, 6 Jan 2021 14:58:20 +0200 Message-Id: <20210106125822.31315-3-tony@atomide.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210106125822.31315-1-tony@atomide.com> References: <20210106125822.31315-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Because of errata i689 the keyboard can idle with state where no key up interrupts are seen until after the next key press. This means we need to first check for any lost key up events before scanning for new down events. For example, rapidly pressing shift-shift-j can sometimes produce a J instead of j. Let's fix the issue by scanning the keyboard in two phases. First we scan for any key up events that we may have missed, and then we scan for key down events. Let's also simplify things with for_each_set_bit() as suggested by Dmitry Torokhov . Cc: Arthur Demchenkov Cc: Carl Philipp Klemm Cc: Merlijn Wajer Cc: Pavel Machek Cc: ruleh Cc: Sebastian Reichel Signed-off-by: Tony Lindgren --- drivers/input/keyboard/omap4-keypad.c | 70 ++++++++++++++++++--------- 1 file changed, 47 insertions(+), 23 deletions(-) diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c --- a/drivers/input/keyboard/omap4-keypad.c +++ b/drivers/input/keyboard/omap4-keypad.c @@ -78,7 +78,7 @@ struct omap4_keypad { u32 irqreg_offset; unsigned int row_shift; bool no_autorepeat; - unsigned char key_state[8]; + u64 keys; unsigned short *keymap; }; @@ -107,6 +107,41 @@ static void kbd_write_irqreg(struct omap4_keypad *keypad_data, keypad_data->base + keypad_data->irqreg_offset + offset); } +static int omap4_keypad_scan_state(struct omap4_keypad *keypad_data, u64 keys, + bool down) +{ + struct input_dev *input_dev = keypad_data->input; + unsigned int col, row, code; + DECLARE_BITMAP(mask, 64); + unsigned long bit; + int events = 0; + bool key_down; + u64 changed; + + changed = keys ^ keypad_data->keys; + bitmap_from_u64(mask, changed); + + for_each_set_bit(bit, mask, keypad_data->rows * BITS_PER_BYTE) { + row = bit / BITS_PER_BYTE; + col = bit % BITS_PER_BYTE; + code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift); + + if (BIT_ULL(bit) & keys) + key_down = true; + else + key_down = false; + + if (key_down != down) + continue; + + input_event(input_dev, EV_MSC, MSC_SCAN, code); + input_report_key(input_dev, keypad_data->keymap[code], + key_down); + events++; + } + + return events; +} /* Interrupt handlers */ static irqreturn_t omap4_keypad_irq_handler(int irq, void *dev_id) @@ -123,34 +158,23 @@ static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id) { struct omap4_keypad *keypad_data = dev_id; struct input_dev *input_dev = keypad_data->input; - unsigned char key_state[ARRAY_SIZE(keypad_data->key_state)]; - unsigned int col, row, code, changed; - u32 *new_state = (u32 *) key_state; + int keys_up, keys_down; + u32 low, high; + u64 keys; - *new_state = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0); - *(new_state + 1) = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32); + low = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0); + high = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32); + keys = low | (u64)high << 32; - for (row = 0; row < keypad_data->rows; row++) { - changed = key_state[row] ^ keypad_data->key_state[row]; - if (!changed) - continue; + /* Scan for key up events for lost key-up interrupts */ + keys_up = omap4_keypad_scan_state(keypad_data, keys, false); - for (col = 0; col < keypad_data->cols; col++) { - if (changed & (1 << col)) { - code = MATRIX_SCAN_CODE(row, col, - keypad_data->row_shift); - input_event(input_dev, EV_MSC, MSC_SCAN, code); - input_report_key(input_dev, - keypad_data->keymap[code], - key_state[row] & (1 << col)); - } - } - } + /* Scan for key down events */ + keys_down = omap4_keypad_scan_state(keypad_data, keys, true); input_sync(input_dev); - memcpy(keypad_data->key_state, key_state, - sizeof(keypad_data->key_state)); + keypad_data->keys = keys; /* clear pending interrupts */ kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,