From: Michael Durrant <mdurrant@arcturusnetworks.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] ColdFire I2C implementing I2C idle [PATCH] -- resent in git format
Date: Wed, 20 Jan 2010 13:33:27 -0500 [thread overview]
Message-ID: <4B574C77.2040802@arcturusnetworks.com> (raw)
In-Reply-To: <4B561B06.7020204@arcturusnetworks.com>
drivers_i2c_fsl_i2c.patch
- need to set I2C to be idle according to the MCF5282 user's manual
If I2SR[IBB] is set when the I2C bus module is enabled,
execute the following code sequence before proceeding with
normal initialization code. This issues a STOP command to the
slave device, placing it in idle state as if it were just
power-cycled on.
I2CR = 0x0
I2CR = 0xA
dummy read of I2DR
I2SR = 0x0
I2CR = 0x0
Signed-off-by: David Wu <davidwu@arcturusnetworks.com>
Signed-off-by: Michael Durrant <mdurrant@arcturusnetworks.com>
---
drivers/i2c/fsl_i2c.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
index 2241990..bce750c 100644
--- a/drivers/i2c/fsl_i2c.c
+++ b/drivers/i2c/fsl_i2c.c
@@ -251,12 +251,25 @@ i2c_init(int speed, int slaveadd)
#endif
}
+static __inline__ int i2c_set_idle(void)
+{
+ writeb(0, &i2c_dev[i2c_bus_num]->cr);
+ writeb(I2C_CR_MEN | I2C_CR_MSTA, &i2c_dev[i2c_bus_num]->cr);
+ readb(&i2c_dev[i2c_bus_num]->dr);
+ writeb(0, &i2c_dev[i2c_bus_num]->sr);
+ writeb(0, &i2c_dev[i2c_bus_num]->cr);
+ writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr);
+}
+
static int
i2c_wait4bus(void)
{
unsigned long long timeval = get_ticks();
const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
+ if (readb(&i2c_dev[i2c_bus_num]->sr) & I2C_SR_MBB)
+ i2c_set_idle();
+
while (readb(&i2c_dev[i2c_bus_num]->sr) & I2C_SR_MBB) {
if ((get_ticks() - timeval) > timeout)
return -1;
-- 1.4.3.4
next prev parent reply other threads:[~2010-01-20 18:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-19 20:50 [U-Boot] ColdFire I2C implementing I2C idle [PATCH] Michael Durrant
2010-01-20 8:26 ` Heiko Schocher
2010-01-20 18:33 ` Michael Durrant [this message]
2010-01-21 7:25 ` [U-Boot] ColdFire I2C implementing I2C idle [PATCH] -- resent in git format Heiko Schocher
2010-01-21 7:41 ` Joakim Tjernlund
2010-01-21 8:04 ` Heiko Schocher
2010-01-21 10:29 ` Wolfgang Wegner
2010-01-21 11:49 ` Heiko Schocher
2010-01-21 17:49 ` Michael Durrant
2010-01-25 8:17 ` Heiko Schocher
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