Dear Heiko Schocher,
Hello Marek,
[...]
diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c index 006fb91..b040535 100644 --- a/drivers/i2c/mxs_i2c.c +++ b/drivers/i2c/mxs_i2c.c @@ -28,6 +28,7 @@
#include<common.h> #include<malloc.h>
+#include<i2c.h>
#include<asm/errno.h> #include<asm/io.h> #include<asm/arch/clock.h>
@@ -40,6 +41,7 @@ void mxs_i2c_reset(void)
{
struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE; int ret;
int speed = i2c_get_bus_speed();
ret = mxs_reset_block(&i2c_regs->hw_i2c_ctrl0_reg); if (ret) {
@@ -53,6 +55,8 @@ void mxs_i2c_reset(void)
&i2c_regs->hw_i2c_ctrl1_clr);writel(I2C_QUEUECTRL_PIO_QUEUE_MODE,&i2c_regs->hw_i2c_queuectrl_set);
i2c_set_bus_speed(speed);
}
This change is not described in the patch description, please fix.
I suspect I'll move this to a separate patch.
void mxs_i2c_setup_read(uint8_t chip, int len)
@@ -210,62 +214,29 @@ int i2c_probe(uchar chip)
return ret;
}
-static struct mxs_i2c_speed_table {
[...]
int i2c_set_bus_speed(unsigned int speed) {
struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
struct mxs_i2c_speed_table *spd = mxs_i2c_speed_to_cfg(speed);
if (!spd) {
printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
- uint32_t clk = mxc_get_clock(MXC_XTAL_CLK);
- uint32_t base = ((clk / speed) - 38) / 2;
- uint16_t high_count = base + 3;
- uint16_t low_count = base - 3;
- uint16_t rcv_count = (high_count * 3) / 4;
- uint16_t xmit_count = low_count / 4;
a lot of magic constants ...
True ... and they have no other meaning than to align stuff on the scope ;-)
if (speed> 540000) {
printf("MXS I2C: Speed too high (%d Hz)\n", speed);return -EINVAL;}
if (speed< 12000) {
printf("MXS I2C: Speed too low (%d Hz)\n", speed);return -EINVAL;
}
- writel(spd->timing0,&i2c_regs->hw_i2c_timing0);
- writel(spd->timing1,&i2c_regs->hw_i2c_timing1);
- writel((high_count<< 16) | rcv_count,&i2c_regs->hw_i2c_timing0);
- writel((low_count<< 16) | xmit_count,&i2c_regs->hw_i2c_timing1);
^ ^ spaces
Could this be your mailer's issue?
[...]
... and here a lot of magic constants too ... as this is a result of measuring ... we should at least note here, that we have this values from a scope session and the values in the manual seem to be not correct ...
True.
Hmm... I am a little confused ... you write the i2c_regs->hw_i2c_timing{0,1,2} registers in i2c_set_bus_speed() but you return in i2c_get_bus_speed() just results from reading the i2c_regs->hw_i2c_timing0 register only and do some funny calculations ... is this correct?
Yes, the speed is configured upon boot anyway, so the timing0 register contains result of previous call to i2c_set_bus_speed(). And if it doesn't, we can't properly determine the speed anyway :(
}
void i2c_init(int speed, int slaveadd)
Thanks!
bye, Heiko