The TWSI_FREQUENCY macro was wrong in 2 ways:
1) It was casting the result of the calculations to an u8, while i2c clk
rates are often >= 100Khz which won't fit in a u8, drop the cast.
2) It had an extra factor of 2 in the divider which neither the datasheet nor
the Linux driver have.
The comment for the default value was wrongly saying that m lives in
bits 4-7, while in reality it is in bits 3-6, as can be seen from the correct
shift by 3 used in i2c_init().
While at it remove the unused twsi_actual_speed variable.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
*/
#define TWSI_FREQUENCY(m, n) \
*/
#define TWSI_FREQUENCY(m, n) \
- ((u8) (CONFIG_SYS_TCLK / (10 * (m + 1) * 2 * (1 << n))))
+ (CONFIG_SYS_TCLK / (10 * (m + 1) * (1 << n)))
/*
* These are required to be reprogrammed before enabling the controller
/*
* These are required to be reprogrammed before enabling the controller
* twsi_slave_address left uninitialized lest checkpatch.pl complains.
*/
* twsi_slave_address left uninitialized lest checkpatch.pl complains.
*/
-/* Baudrate generator: m (bits 7..4) =4, n (bits 3..0) =4 */
+/* Baudrate generator: m (bits 6..3) = 8, n (bits 2..0) = 4 */
static u8 twsi_baud_rate = 0x44; /* baudrate at controller reset */
static u8 twsi_baud_rate = 0x44; /* baudrate at controller reset */
-/* Default frequency corresponding to default m=4, n=4 */
-static u8 twsi_actual_speed = TWSI_FREQUENCY(4, 4);
/* Default slave address is 0 (so is an uninitialized static) */
static u8 twsi_slave_address;
/* Default slave address is 0 (so is an uninitialized static) */
static u8 twsi_slave_address;
}
/* save baud rate and slave for later calls to twsi_reset */
twsi_baud_rate = baud;
}
/* save baud rate and slave for later calls to twsi_reset */
twsi_baud_rate = baud;
- twsi_actual_speed = highest_speed;
twsi_slave_address = slaveadd;
/* reset controller */
twsi_reset();
twsi_slave_address = slaveadd;
/* reset controller */
twsi_reset();