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[60.250.192.107]) by smtp.gmail.com with ESMTPSA id w13-20020a170902d3cd00b001b9fef7f454sm1291516plb.73.2023.07.18.01.45.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Jul 2023 01:45:48 -0700 (PDT) From: Mia Lin To: avifishman70@gmail.com, tmaimon77@gmail.com, tali.perry1@gmail.com, venture@google.com, yuenn@google.com, benjaminfair@google.com, a.zummo@towertech.it, alexandre.belloni@bootlin.com, KWLIU@nuvoton.com, JJLIU0@nuvoton.com, KFLIN@nuvoton.com, YHYANG2@nuvoton.com, mylin1@nuvoton.com Cc: openbmc@lists.ozlabs.org, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Mia Lin Subject: [PATCH 1/1] RTC: nuvoton: Modify the setting timing of write ownership Date: Tue, 18 Jul 2023 16:45:35 +0800 Message-Id: <20230718084535.11081-2-mimi05633@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230718084535.11081-1-mimi05633@gmail.com> References: <20230718084535.11081-1-mimi05633@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" - Change the write ownership to default. - Set the TWO bit to gain write ownership for BMC before it updates time. - Restore the TWO bit after BMC updates the time. - Set 24-Hour Format. Signed-off-by: Mia Lin --- drivers/rtc/rtc-nct3018y.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-nct3018y.c b/drivers/rtc/rtc-nct3018y.c index a4e3f924837e..e6b06724cdef 100644 --- a/drivers/rtc/rtc-nct3018y.c +++ b/drivers/rtc/rtc-nct3018y.c @@ -178,7 +178,19 @@ static int nct3018y_rtc_set_time(struct device *dev, s= truct rtc_time *tm) { struct i2c_client *client =3D to_i2c_client(dev); unsigned char buf[4] =3D {0}; - int err; + int err, flags, restore_flags =3D 0; + + /* Check and set TWO bit */ + flags =3D i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL); + if (!(flags & NCT3018Y_BIT_TWO)) { + restore_flags =3D 1; + flags |=3D NCT3018Y_BIT_TWO; + err =3D i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags); + if (err < 0) { + dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n"); + return err; + } + } =20 buf[0] =3D bin2bcd(tm->tm_sec); err =3D i2c_smbus_write_byte_data(client, NCT3018Y_REG_SC, buf[0]); @@ -212,6 +224,16 @@ static int nct3018y_rtc_set_time(struct device *dev, s= truct rtc_time *tm) return -EIO; } =20 + /* Restore TWO bit */ + if (restore_flags) { + flags &=3D ~NCT3018Y_BIT_TWO; + err =3D i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags); + if (err < 0) { + dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n"); + return err; + } + } + return err; } =20 @@ -479,7 +501,7 @@ static int nct3018y_probe(struct i2c_client *client) dev_dbg(&client->dev, "%s: NCT3018Y_BIT_TWO is set\n", __func__); } =20 - flags =3D NCT3018Y_BIT_TWO; + flags =3D NCT3018Y_BIT_HF; err =3D i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags); if (err < 0) { dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n"); --=20 2.17.1