From: John Keeping <john@metanate.com>
To: Heiko Stuebner <heiko@sntech.de>
Cc: John Keeping <john@metanate.com>,
linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org, linux-i2c@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] i2c: rk3x: support master_xfer_atomic
Date: Tue, 23 Jun 2020 13:06:46 +0100 [thread overview]
Message-ID: <20200623120646.2175569-1-john@metanate.com> (raw)
Enable i2c transactions in irq disabled contexts like poweroff where the
PMIC is connected via i2c.
Signed-off-by: John Keeping <john@metanate.com>
---
drivers/i2c/busses/i2c-rk3x.c | 39 +++++++++++++++++++++++++++++++----
1 file changed, 35 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 15324bfbc6cb..8e3cc85d1921 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
+#include <linux/iopoll.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/platform_device.h>
@@ -1040,8 +1041,21 @@ static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, int num)
return ret;
}
-static int rk3x_i2c_xfer(struct i2c_adapter *adap,
- struct i2c_msg *msgs, int num)
+static int rk3x_i2c_wait_xfer_poll(struct rk3x_i2c *i2c)
+{
+ ktime_t timeout = ktime_add_ms(ktime_get(), WAIT_TIMEOUT);
+
+ while (READ_ONCE(i2c->busy) &&
+ ktime_compare(ktime_get(), timeout) < 0) {
+ udelay(5);
+ rk3x_i2c_irq(0, i2c);
+ }
+
+ return !i2c->busy;
+}
+
+static int rk3x_i2c_xfer_common(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num, bool polling)
{
struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data;
unsigned long timeout, flags;
@@ -1075,8 +1089,12 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
rk3x_i2c_start(i2c);
- timeout = wait_event_timeout(i2c->wait, !i2c->busy,
- msecs_to_jiffies(WAIT_TIMEOUT));
+ if (!polling) {
+ timeout = wait_event_timeout(i2c->wait, !i2c->busy,
+ msecs_to_jiffies(WAIT_TIMEOUT));
+ } else {
+ timeout = rk3x_i2c_wait_xfer_poll(i2c);
+ }
spin_lock_irqsave(&i2c->lock, flags);
@@ -1110,6 +1128,18 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
return ret < 0 ? ret : num;
}
+static int rk3x_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ return rk3x_i2c_xfer_common(adap, msgs, num, false);
+}
+
+static int rk3x_i2c_xfer_polling(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ return rk3x_i2c_xfer_common(adap, msgs, num, true);
+}
+
static __maybe_unused int rk3x_i2c_resume(struct device *dev)
{
struct rk3x_i2c *i2c = dev_get_drvdata(dev);
@@ -1126,6 +1156,7 @@ static u32 rk3x_i2c_func(struct i2c_adapter *adap)
static const struct i2c_algorithm rk3x_i2c_algorithm = {
.master_xfer = rk3x_i2c_xfer,
+ .master_xfer_atomic = rk3x_i2c_xfer_polling,
.functionality = rk3x_i2c_func,
};
--
2.27.0
next reply other threads:[~2020-06-23 12:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 12:06 John Keeping [this message]
2020-07-03 10:08 ` [PATCH] i2c: rk3x: support master_xfer_atomic Heiko Stuebner
2020-07-04 6:46 ` Wolfram Sang
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=20200623120646.2175569-1-john@metanate.com \
--to=john@metanate.com \
--cc=heiko@sntech.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).