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authorWolfram Sang <wsa+renesas@sang-engineering.com>2018-07-11 00:24:22 +0200
committerWolfram Sang <wsa@the-dreams.de>2018-07-17 10:46:51 +0200
commit7ca5f6be7900ca753ed01c0202dc5f998a41f4ee (patch)
tree3648c63c59b230dfcd24f7fef705e77cf90ef39f /drivers/i2c/i2c-core-base.c
parent0b71026c69caa10261218528326721828d29a481 (diff)
downloadlinux-7ca5f6be7900ca753ed01c0202dc5f998a41f4ee.tar.bz2
i2c: recovery: add get_bus_free callback
Some IP cores have an internal 'bus free' logic which may be more advanced than just checking if SDA is high. Add a separate callback to get this status. Filling it is optional. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/i2c-core-base.c')
-rw-r--r--drivers/i2c/i2c-core-base.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index c7995efd58ea..59f8dfc5be36 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -158,6 +158,22 @@ static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
}
+static int i2c_generic_bus_free(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ int ret = -EOPNOTSUPP;
+
+ if (bri->get_bus_free)
+ ret = bri->get_bus_free(adap);
+ else if (bri->get_sda)
+ ret = bri->get_sda(adap);
+
+ if (ret < 0)
+ return ret;
+
+ return ret ? 0 : -EBUSY;
+}
+
/*
* We are generating clock pulses. ndelay() determines durating of clk pulses.
* We will generate clock with rate 100 KHz and so duration of both clock levels
@@ -169,7 +185,7 @@ static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
int i2c_generic_scl_recovery(struct i2c_adapter *adap)
{
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
- int i = 0, val = 1, ret = 0;
+ int i = 0, val = 1, ret;
if (bri->prepare_recovery)
bri->prepare_recovery(adap);
@@ -207,14 +223,17 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
bri->set_sda(adap, val);
ndelay(RECOVERY_NDELAY / 2);
- /* Break if SDA is high */
- if (val && bri->get_sda) {
- ret = bri->get_sda(adap) ? 0 : -EBUSY;
+ if (val) {
+ ret = i2c_generic_bus_free(adap);
if (ret == 0)
break;
}
}
+ /* If we can't check bus status, assume recovery worked */
+ if (ret == -EOPNOTSUPP)
+ ret = 0;
+
if (bri->unprepare_recovery)
bri->unprepare_recovery(adap);