From: Alexander Sverdlin <alexander.sverdlin@nokia.com>
To: linux-i2c@vger.kernel.org
Cc: Sekhar Nori <nsekhar@ti.com>,
Alexander Sverdlin <alexander.sverdlin@nokia.com>,
linux-arm-kernel@lists.infradead.org,
Kevin Hilman <khilman@kernel.org>
Subject: [PATCH] i2c: davinci: Avoid zero value of CLKH
Date: Fri, 13 Jul 2018 17:20:17 +0200 [thread overview]
Message-ID: <20180713152017.2207-1-alexander.sverdlin@nokia.com> (raw)
If CLKH is set to 0 I2C clock is not generated at all, so avoid this value
and stretch the clock in this case.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
---
drivers/i2c/busses/i2c-davinci.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 75d6ab177055..7379043711df 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -237,12 +237,16 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
/*
* It's not always possible to have 1 to 2 ratio when d=7, so fall back
* to minimal possible clkh in this case.
+ *
+ * Note:
+ * CLKH is not allowed to be 0, in this case I2C clock is not generated
+ * at all
*/
- if (clk >= clkl + d) {
+ if (clk > clkl + d) {
clkh = clk - clkl - d;
clkl -= d;
} else {
- clkh = 0;
+ clkh = 1;
clkl = clk - (d << 1);
}
--
2.18.0
WARNING: multiple messages have this Message-ID (diff)
From: alexander.sverdlin@nokia.com (Alexander Sverdlin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: davinci: Avoid zero value of CLKH
Date: Fri, 13 Jul 2018 17:20:17 +0200 [thread overview]
Message-ID: <20180713152017.2207-1-alexander.sverdlin@nokia.com> (raw)
If CLKH is set to 0 I2C clock is not generated at all, so avoid this value
and stretch the clock in this case.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
---
drivers/i2c/busses/i2c-davinci.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 75d6ab177055..7379043711df 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -237,12 +237,16 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
/*
* It's not always possible to have 1 to 2 ratio when d=7, so fall back
* to minimal possible clkh in this case.
+ *
+ * Note:
+ * CLKH is not allowed to be 0, in this case I2C clock is not generated
+ * at all
*/
- if (clk >= clkl + d) {
+ if (clk > clkl + d) {
clkh = clk - clkl - d;
clkl -= d;
} else {
- clkh = 0;
+ clkh = 1;
clkl = clk - (d << 1);
}
--
2.18.0
next reply other threads:[~2018-07-13 15:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-13 15:20 Alexander Sverdlin [this message]
2018-07-13 15:20 ` [PATCH] i2c: davinci: Avoid zero value of CLKH Alexander Sverdlin
2018-07-17 11:57 ` Sekhar Nori
2018-07-17 11:57 ` Sekhar Nori
2018-07-20 18:43 ` Grygorii Strashko
2018-07-20 18:43 ` Grygorii Strashko
2018-07-20 22:18 ` Wolfram Sang
2018-07-20 22:18 ` Wolfram Sang
2018-07-23 18:07 ` Wolfram Sang
2018-07-23 18:07 ` Wolfram Sang
2018-07-24 6:17 ` Sekhar Nori
2018-07-24 6:17 ` Sekhar Nori
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180713152017.2207-1-alexander.sverdlin@nokia.com \
--to=alexander.sverdlin@nokia.com \
--cc=khilman@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-i2c@vger.kernel.org \
--cc=nsekhar@ti.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.