From patchwork Wed Aug 2 16:07:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 709432 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3790C04FE0 for ; Wed, 2 Aug 2023 16:08:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229913AbjHBQIR (ORCPT ); Wed, 2 Aug 2023 12:08:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235485AbjHBQH7 (ORCPT ); Wed, 2 Aug 2023 12:07:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BAD01981 for ; Wed, 2 Aug 2023 09:07:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9C11461A24 for ; Wed, 2 Aug 2023 16:07:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18101C433CA; Wed, 2 Aug 2023 16:07:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690992475; bh=1sJMn5zHlsQRF/6HJlV+cFo3X9IzKb30odH+NLo3VR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tVJE8MFZGjWq0wK+tblZdE0Y5DhXdXrr+bNj0AfFGiHslHBJBndkoE6jO3kkX6nvY kHF8h/38ztd0G9PcWkjb8jYFx3IYyaEORVIUoAgqNQrk2mxVrAjviVuuEeIRapIdmO 86fCHYos2TWEhtQshyudG8cWmxUNVu9HJRnmLbQjc5/Nb5J+JUjVJl/9M6tWZOt+8Y KpyVQbSp7O6USa/1pekxJEWYcyruyDZLRc98CUNj/3gj2L+ekWeG6q9tQyGv2OJbQ5 Tt1L0PaYpp/zA8IrOdDC4Q6YZd/illyq4hXHX4KTRE1E4hwBmKxFd8Nisd7gw84fvK F+ttdJ6p1vjag== From: =?utf-8?q?Marek_Beh=C3=BAn?= To: Pavel Machek , Lee Jones , linux-leds@vger.kernel.org Cc: =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH v3 2/6] leds: turris-omnia: do not use SMBUS calls Date: Wed, 2 Aug 2023 18:07:44 +0200 Message-ID: <20230802160748.11208-3-kabel@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230802160748.11208-1-kabel@kernel.org> References: <20230802160748.11208-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org The leds-turris-omnia driver uses three function for I2C access: - i2c_smbus_write_byte_data() and i2c_smbus_read_byte_data(), which cause an emulated SMBUS transfer, - i2c_master_send(), which causes an ordinary I2C transfer. The Turris Omnia MCU LED controller is not semantically SMBUS, it operates as a simple I2C bus. It does not implement any of the SMBUS specific features, like PEC, or procedure calls, or anything. Moreover the I2C controller driver also does not implement SMBUS, and so the emulated SMBUS procedure from drivers/i2c/i2c-core-smbus.c is used for the SMBUS calls, which gives an unnecessary overhead. When I first wrote the driver, I was unaware of these facts, and I simply used the first function that worked. Drop the I2C SMBUS calls and instead use simple I2C transfers. Fixes: 089381b27abe ("leds: initial support for Turris Omnia LEDs") Signed-off-by: Marek Behún --- drivers/leds/leds-turris-omnia.c | 56 +++++++++++++++++++++++++------- 1 file changed, 44 insertions(+), 12 deletions(-) diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c index bbd610100e41..bb2a2b411a56 100644 --- a/drivers/leds/leds-turris-omnia.c +++ b/drivers/leds/leds-turris-omnia.c @@ -2,7 +2,7 @@ /* * CZ.NIC's Turris Omnia LEDs driver * - * 2020 by Marek Behún + * 2020, 2023 by Marek Behún */ #include @@ -41,6 +41,40 @@ struct omnia_leds { struct omnia_led leds[]; }; +static int omnia_cmd_write(const struct i2c_client *client, u8 cmd, u8 val) +{ + u8 buf[2] = { cmd, val }; + int ret; + + ret = i2c_master_send(client, buf, sizeof(buf)); + + return ret < 0 ? ret : 0; +} + +static int omnia_cmd_read(const struct i2c_client *client, u8 cmd) +{ + struct i2c_msg msgs[2]; + u8 reply; + int ret; + + msgs[0].addr = client->addr; + msgs[0].flags = 0; + msgs[0].len = 1; + msgs[0].buf = &cmd; + msgs[1].addr = client->addr; + msgs[1].flags = I2C_M_RD; + msgs[1].len = 1; + msgs[1].buf = &reply; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (likely(ret == ARRAY_SIZE(msgs))) + return reply; + else if (ret < 0) + return ret; + else + return -EIO; +} + static int omnia_led_brightness_set_blocking(struct led_classdev *cdev, enum led_brightness brightness) { @@ -64,7 +98,7 @@ static int omnia_led_brightness_set_blocking(struct led_classdev *cdev, if (buf[2] || buf[3] || buf[4]) state |= CMD_LED_STATE_ON; - ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_STATE, state); + ret = omnia_cmd_write(leds->client, CMD_LED_STATE, state); if (ret >= 0 && (state & CMD_LED_STATE_ON)) ret = i2c_master_send(leds->client, buf, 5); @@ -114,9 +148,8 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led, cdev->brightness_set_blocking = omnia_led_brightness_set_blocking; /* put the LED into software mode */ - ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE, - CMD_LED_MODE_LED(led->reg) | - CMD_LED_MODE_USER); + ret = omnia_cmd_write(client, CMD_LED_MODE, CMD_LED_MODE_LED(led->reg) | + CMD_LED_MODE_USER); if (ret < 0) { dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np, ret); @@ -124,8 +157,8 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led, } /* disable the LED */ - ret = i2c_smbus_write_byte_data(client, CMD_LED_STATE, - CMD_LED_STATE_LED(led->reg)); + ret = omnia_cmd_write(client, CMD_LED_STATE, + CMD_LED_STATE_LED(led->reg)); if (ret < 0) { dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret); return ret; @@ -158,7 +191,7 @@ static ssize_t brightness_show(struct device *dev, struct device_attribute *a, struct i2c_client *client = to_i2c_client(dev); int ret; - ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS); + ret = omnia_cmd_read(client, CMD_LED_GET_BRIGHTNESS); if (ret < 0) return ret; @@ -179,8 +212,7 @@ static ssize_t brightness_store(struct device *dev, struct device_attribute *a, if (brightness > 100) return -EINVAL; - ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS, - (u8)brightness); + ret = omnia_cmd_write(client, CMD_LED_SET_BRIGHTNESS, brightness); return ret < 0 ? ret : count; } @@ -237,8 +269,8 @@ static void omnia_leds_remove(struct i2c_client *client) u8 buf[5]; /* put all LEDs into default (HW triggered) mode */ - i2c_smbus_write_byte_data(client, CMD_LED_MODE, - CMD_LED_MODE_LED(OMNIA_BOARD_LEDS)); + omnia_cmd_write(client, CMD_LED_MODE, + CMD_LED_MODE_LED(OMNIA_BOARD_LEDS)); /* set all LEDs color to [255, 255, 255] */ buf[0] = CMD_LED_COLOR;