From mboxrd@z Thu Jan 1 00:00:00 1970 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 49293C04A95 for ; Sun, 25 Sep 2022 07:12:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229525AbiIYHMA (ORCPT ); Sun, 25 Sep 2022 03:12:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbiIYHL7 (ORCPT ); Sun, 25 Sep 2022 03:11:59 -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 1C12325C5E for ; Sun, 25 Sep 2022 00:11:58 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AC0AA60B9A for ; Sun, 25 Sep 2022 07:11:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3B5FC433D6; Sun, 25 Sep 2022 07:11:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664089917; bh=V7tE8zOiizg0rA2VDoUhWNh+SL0LgbplurY2m7C1Z60=; h=Subject:To:From:Date:From; b=I6XmisU2qxZAtzV20Xi8mYNBpNckdYZEb28xn5VqNGffkVmd3DwXOXqqWtNrE9Oiu 3zh4R6ETfDC5cRavF9INoo1sL+BJfgHaOHbz5WCUmBMoxzxmd5QvJlKYHa+vlJ3E2e JJAnPHjbS86CZu2z1UrfsikCFYYCmtD0EL0O1Pvs= Subject: patch "iio: dac: ad5593r: Fix i2c read protocol requirements" added to char-misc-testing To: michael.hennerich@analog.com, Jonathan.Cameron@huawei.com, Stable@vger.kernel.org, nuno.sa@analog.com From: Date: Sun, 25 Sep 2022 09:09:56 +0200 Message-ID: <1664089796246210@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled iio: dac: ad5593r: Fix i2c read protocol requirements to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the char-misc-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 558a25f903b4af6361b7fbeea08a6446a0745653 Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Tue, 13 Sep 2022 09:34:12 +0200 Subject: iio: dac: ad5593r: Fix i2c read protocol requirements MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit For reliable operation across the full range of supported interface rates, the AD5593R needs a STOP condition between address write, and data read (like show in the datasheet Figure 40) so in turn i2c_smbus_read_word_swapped cannot be used. While at it, a simple helper was added to make the code simpler. Fixes: 56ca9db862bf ("iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs") Signed-off-by: Michael Hennerich Signed-off-by: Nuno Sá Cc: Link: https://lore.kernel.org/r/20220913073413.140475-2-nuno.sa@analog.com Signed-off-by: Jonathan Cameron --- drivers/iio/dac/ad5593r.c | 46 +++++++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 19 deletions(-) diff --git a/drivers/iio/dac/ad5593r.c b/drivers/iio/dac/ad5593r.c index 34e1319a9712..356dc0bab115 100644 --- a/drivers/iio/dac/ad5593r.c +++ b/drivers/iio/dac/ad5593r.c @@ -13,6 +13,8 @@ #include #include +#include + #define AD5593R_MODE_CONF (0 << 4) #define AD5593R_MODE_DAC_WRITE (1 << 4) #define AD5593R_MODE_ADC_READBACK (4 << 4) @@ -20,6 +22,24 @@ #define AD5593R_MODE_GPIO_READBACK (6 << 4) #define AD5593R_MODE_REG_READBACK (7 << 4) +static int ad5593r_read_word(struct i2c_client *i2c, u8 reg, u16 *value) +{ + int ret; + u8 buf[2]; + + ret = i2c_smbus_write_byte(i2c, reg); + if (ret < 0) + return ret; + + ret = i2c_master_recv(i2c, buf, sizeof(buf)); + if (ret < 0) + return ret; + + *value = get_unaligned_be16(buf); + + return 0; +} + static int ad5593r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value) { struct i2c_client *i2c = to_i2c_client(st->dev); @@ -38,13 +58,7 @@ static int ad5593r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value) if (val < 0) return (int) val; - val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK); - if (val < 0) - return (int) val; - - *value = (u16) val; - - return 0; + return ad5593r_read_word(i2c, AD5593R_MODE_ADC_READBACK, value); } static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value) @@ -58,25 +72,19 @@ static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value) static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value) { struct i2c_client *i2c = to_i2c_client(st->dev); - s32 val; - - val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_REG_READBACK | reg); - if (val < 0) - return (int) val; - *value = (u16) val; - - return 0; + return ad5593r_read_word(i2c, AD5593R_MODE_REG_READBACK | reg, value); } static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value) { struct i2c_client *i2c = to_i2c_client(st->dev); - s32 val; + u16 val; + int ret; - val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_GPIO_READBACK); - if (val < 0) - return (int) val; + ret = ad5593r_read_word(i2c, AD5593R_MODE_GPIO_READBACK, &val); + if (ret) + return ret; *value = (u8) val; -- 2.37.3