Add support for atomic transfers using polling mode with interrupts
intentionally disabled to get rid of the following warning introduced by
commit 63b96983a5dd ("i2c: core: introduce callbacks for atomic
transfers") during system reboot and power-off:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1518 at drivers/i2c/i2c-core.h:40 i2c_transfer+0xe8/0xf4
No atomic I2C transfer handler for 'i2c-0'
Modules linked in:
CPU: 0 PID: 1518 Comm: reboot Not tainted 6.6.0-next-20231031 #7453
Hardware name: Samsung Exynos (Flattened Device Tree)
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x40/0x4c
dump_stack_lvl from __warn+0x7c/0x124
__warn from warn_slowpath_fmt+0x110/0x178
warn_slowpath_fmt from i2c_transfer+0xe8/0xf4
i2c_transfer from regmap_i2c_read+0x58/0x88
regmap_i2c_read from _regmap_raw_read+0xfc/0x260
_regmap_raw_read from _regmap_bus_read+0x44/0x70
_regmap_bus_read from _regmap_read+0x60/0x14c
_regmap_read from regmap_read+0x3c/0x60
regmap_read from regulator_get_voltage_sel_regmap+0x2c/0x74
regulator_get_voltage_sel_regmap from regulator_get_voltage_rdev+0x64/0x15c
regulator_get_voltage_rdev from _regulator_do_set_voltage+0x2c/0x5a8
_regulator_do_set_voltage from regulator_set_voltage_rdev+0x90/0x248
regulator_set_voltage_rdev from regulator_do_balance_voltage+0x350/0x4d0
regulator_do_balance_voltage from regulator_set_voltage_unlocked+0xd4/0x118
regulator_set_voltage_unlocked from regulator_set_voltage+0x40/0x74
regulator_set_voltage from _opp_config_regulator_single+0x44/0x110
_opp_config_regulator_single from _set_opp+0x118/0x500
_set_opp from dev_pm_opp_set_rate+0x108/0x20c
dev_pm_opp_set_rate from __cpufreq_driver_target+0x568/0x6cc
__cpufreq_driver_target from cpufreq_generic_suspend+0x28/0x50
cpufreq_generic_suspend from cpufreq_suspend+0xbc/0x124
cpufreq_suspend from device_shutdown+0x18/0x230
device_shutdown from kernel_restart+0x38/0x90
kernel_restart from __do_sys_reboot+0x12c/0x1f8
__do_sys_reboot from ret_fast_syscall+0x0/0x54
Exception stack(0xf0fedfa8 to 0xf0fedff0)
...
---[ end trace 0000000000000000 ]---
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reviewed-by: Chanho Park <chanho61.park@xxxxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-s3c2410.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index c0fe96a4f2c4..275f7c42165c 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -76,6 +76,7 @@
#define QUIRK_HDMIPHY (1 << 1)
#define QUIRK_NO_GPIO (1 << 2)
#define QUIRK_POLL (1 << 3)
+#define QUIRK_ATOMIC (1 << 4)
/* Max time to wait for bus to become idle after a xfer (in us) */
#define S3C2410_IDLE_TIMEOUT 5000
@@ -174,7 +175,7 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
if (ret)
i2c->msg_idx = ret;
- if (!(i2c->quirks & QUIRK_POLL))
+ if (!(i2c->quirks & (QUIRK_POLL | QUIRK_ATOMIC)))
wake_up(&i2c->wait);
}
@@ -703,7 +704,7 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
s3c24xx_i2c_enable_irq(i2c);
s3c24xx_i2c_message_start(i2c, msgs);
- if (i2c->quirks & QUIRK_POLL) {
+ if (i2c->quirks & (QUIRK_POLL | QUIRK_ATOMIC)) {
while ((i2c->msg_num != 0) && is_ack(i2c)) {
unsigned long stat = readl(i2c->regs + S3C2410_IICSTAT);
@@ -775,6 +776,21 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
return -EREMOTEIO;
}
+static int s3c24xx_i2c_xfer_atomic(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data;
+ int ret;
+
+ disable_irq(i2c->irq);
+ i2c->quirks |= QUIRK_ATOMIC;
+ ret = s3c24xx_i2c_xfer(adap, msgs, num);
+ i2c->quirks &= ~QUIRK_ATOMIC;
+ enable_irq(i2c->irq);
+
+ return ret;
+}
+
/* declare our i2c functionality */
static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
{
@@ -785,6 +801,7 @@ static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
/* i2c bus registration info */
static const struct i2c_algorithm s3c24xx_i2c_algorithm = {
.master_xfer = s3c24xx_i2c_xfer,
+ .master_xfer_atomic = s3c24xx_i2c_xfer_atomic,
.functionality = s3c24xx_i2c_func,
};
--
2.34.1
