powerpc: Cleanup udbg_16550 and add support for LPC PIO-only UARTs

The udbg_16550 code, which we use for our early consoles and debug
backends was fairly messy. Especially for the debug consoles, it
would re-implement the "high level" getc/putc/poll functions for
each access method. It also had code to configure the UART but only
for the straight MMIO method.

This changes it to instead abstract at the register accessor level,
and have the various functions and configuration routines use these.

The result is simpler and slightly smaller code, and free support
for non-MMIO mapped PIO UARTs, which such as the ones that can be
present on a POWER 8 LPC bus.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h
index dc590919f8eb..b51fba10e733 100644
--- a/arch/powerpc/include/asm/udbg.h
+++ b/arch/powerpc/include/asm/udbg.h
@@ -27,10 +27,11 @@ extern void udbg_printf(const char *fmt, ...)
         __attribute__ ((format (printf, 1, 2)));
 extern void udbg_progress(char *s, unsigned short hex);
 
-extern void udbg_init_uart(void __iomem *comport, unsigned int speed,
-                           unsigned int clock);
-extern unsigned int udbg_probe_uart_speed(void __iomem *comport,
-                                          unsigned int clock);
+extern void udbg_uart_init_mmio(void __iomem *addr, unsigned int stride);
+extern void udbg_uart_init_pio(unsigned long port, unsigned int stride);
+
+extern void udbg_uart_setup(unsigned int speed, unsigned int clock);
+extern unsigned int udbg_probe_uart_speed(unsigned int clock);
 
 struct device_node;
 extern void udbg_scc_init(int force_scc);