[U-Boot] [PATCH] i2c: designware_i2c: Restore enable state after set speed
Jun Chen
ptchentw at gmail.com
Wed Jun 5 07:23:16 UTC 2019
Before calling __dw_i2c_set_bus_speed(),
the I2C could already be set as ether enable or disable,
we should restore the original setting instead of enable i2c anyway.
This patch fix a bug happened in init function:
__dw_i2c_init(){
/* Disable i2c */
...
__dw_i2c_set_bus_speed(i2c_base, NULL, speed);
writel(slaveaddr, &i2c_base->ic_sar);
/* Enable i2c */
}
In this case, enable i2c inside __dw_i2c_set_bus_speed() function
will cause ic_sar write fail.
Signed-off-by: Jun Chen <ptchentw at gmail.com>
---
drivers/i2c/designware_i2c.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 9ccc241..d11d47d 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -82,6 +82,7 @@ static unsigned int __dw_i2c_set_bus_speed(struct i2c_regs *i2c_base,
{
unsigned int cntl;
unsigned int hcnt, lcnt;
+ unsigned int ena;
int i2c_spd;
if (speed >= I2C_MAX_SPEED)
@@ -91,6 +92,9 @@ static unsigned int __dw_i2c_set_bus_speed(struct i2c_regs *i2c_base,
else
i2c_spd = IC_SPEED_MODE_STANDARD;
+ /* Get enable setting for restore later */
+ ena = readl(&i2c_base->ic_enable) & IC_ENABLE_0B;
+
/* to set speed cltr must be disabled */
dw_i2c_enable(i2c_base, false);
@@ -146,8 +150,9 @@ static unsigned int __dw_i2c_set_bus_speed(struct i2c_regs *i2c_base,
if (scl_sda_cfg)
writel(scl_sda_cfg->sda_hold, &i2c_base->ic_sda_hold);
- /* Enable back i2c now speed set */
- dw_i2c_enable(i2c_base, true);
+ /* Restore back i2c now speed set */
+ if (ena == IC_ENABLE_0B)
+ dw_i2c_enable(i2c_base, true);
return 0;
}
--
1.9.1
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