i2c: thunderx: Support for High speed mode
To support bus operations for high speed bus frequencies greater than
400KHZ following control bits need to be setup accordingly
- hs_mode (bit 0) field in Mode register to switch controller
between low-speed and high-speed frequency operating mode.
- Setup clock divisors for desired TWSI bus frequency using
FOSCL output frequency divisor (D):
0 - sets the divisor to 10 for low speed mode
1 - sets the divisor to 15 for high speed mode.
The TWSI bus output frequency, in master mode is based on:
TCLK = 100MHz / (THP + 2)
FOSCL = FSAMP / (M+1)×D = TCLK / (2 ^ N × (M + 1) × 15)
FSAMP = TCLK / 2 ^ N
where,
N is <2:0> and M is <6:3> of TWSI Clock Control Register
D is 10 for low speed or 15 for HS_MODE
With high speed mode support, HLC mode usage is limited to
low speed frequency (<=400KHz) bus transfers in hardware.
Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>