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authorJohn Keeping <john@metanate.com>2020-06-23 15:06:46 +0300
committerWolfram Sang <wsa@kernel.org>2020-07-04 09:44:39 +0300
commitf3e2bd713730e6d69e8e021d3ff574f01c39e7e3 (patch)
tree8e1a57ab92da844b0b2ca0c28d7a5a0b014ad73e /drivers/i2c/busses/i2c-rk3x.c
parentf80531c8217c5b348058a0280f3be05835abd737 (diff)
downloadlinux-f3e2bd713730e6d69e8e021d3ff574f01c39e7e3.tar.xz
i2c: rk3x: support master_xfer_atomic
Enable i2c transactions in irq disabled contexts like poweroff where the PMIC is connected via i2c. Signed-off-by: John Keeping <john@metanate.com> Tested-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-rk3x.c')
-rw-r--r--drivers/i2c/busses/i2c-rk3x.c39
1 files changed, 35 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index bc698240c4aa..b67bb54caf27 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,
};