Commit Graph

2 Commits

Author SHA1 Message Date
Phil Edworthy ee02950d53 clk: renesas: r9a06g032: Fix UART34567 clock rate
The clock for UARTs 0 through 2 is UART012, the clock for UARTs 3 through
7 is UART34567.
For UART012, we stop the clock driver from changing the clock rate. This
is because the Synopsys UART driver simply sets the reference clock to 16x
the baud rate, but doesn't check if the actual rate is within the required
tolerance. The RZ/N1 clock divider can't provide this (we have to rely on
the UART's internal divider to set the correct clock rate), so you end up
with a clock rate that is way off what you wanted.

In addition, since the clock is shared between multiple UARTs, you don't
want the driver trying to change the clock rate as it may affect the other
UARTs (which may not have been configured yet, so you don't know what baud
rate they will use). Normally, the clock rate is set early on before Linux
to some very high rate that supports all of the clock rates you want.

This change stops the UART34567 clock rate from changing for the same
reasons.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Fixes: 4c3d88526e ("clk: renesas: Renesas R9A06G032 clock driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
2018-09-11 11:57:25 +02:00
Michel Pollet 4c3d88526e clk: renesas: Renesas R9A06G032 clock driver
This provides a clock driver for the Renesas R09A06G032.
This uses a structure derived from both the R-Car Gen2 driver as well as
the renesas-cpg-mssr driver.

Signed-off-by: Michel Pollet <michel.pollet@bp.renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
2018-06-25 11:17:13 +02:00