cpm_uart: Add generic clock API support to set baudrates
This patch introduces baudrate setting support via the generic clock API.
When present the optional device tree clock property is used instead of
fsl-cpm-brg. Platforms can then define complex clock schemes, to output
the serial clock on an external pin for instance.
Signed-off-by: Laurent Pinchart <laurentp@cse-semaphore.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 18a7183..4c900ef 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -283,6 +283,7 @@
config CPM
bool
+ select PPC_CLOCK
config OF_RTC
bool
diff --git a/drivers/serial/cpm_uart/cpm_uart.h b/drivers/serial/cpm_uart/cpm_uart.h
index 5999ef5..7274b52 100644
--- a/drivers/serial/cpm_uart/cpm_uart.h
+++ b/drivers/serial/cpm_uart/cpm_uart.h
@@ -77,6 +77,7 @@
unsigned char *rx_buf;
u32 flags;
void (*set_lineif)(struct uart_cpm_port *);
+ struct clk *clk;
u8 brg;
uint dp_addr;
void *mem_addr;
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index 5e0c17f..25efca5 100644
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -45,6 +45,7 @@
#include <linux/of_platform.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
+#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
@@ -596,7 +597,10 @@
out_be16(&sccp->scc_psmr, (sbits << 12) | scval);
}
- cpm_set_brg(pinfo->brg - 1, baud);
+ if (pinfo->clk)
+ clk_set_rate(pinfo->clk, baud);
+ else
+ cpm_set_brg(pinfo->brg - 1, baud);
spin_unlock_irqrestore(&port->lock, flags);
}
@@ -1023,13 +1027,21 @@
int ret;
int i;
- data = of_get_property(np, "fsl,cpm-brg", &len);
- if (!data || len != 4) {
- printk(KERN_ERR "CPM UART %s has no/invalid "
- "fsl,cpm-brg property.\n", np->name);
- return -EINVAL;
+ data = of_get_property(np, "clock", NULL);
+ if (data) {
+ struct clk *clk = clk_get(NULL, (const char*)data);
+ if (!IS_ERR(clk))
+ pinfo->clk = clk;
}
- pinfo->brg = *data;
+ if (!pinfo->clk) {
+ data = of_get_property(np, "fsl,cpm-brg", &len);
+ if (!data || len != 4) {
+ printk(KERN_ERR "CPM UART %s has no/invalid "
+ "fsl,cpm-brg property.\n", np->name);
+ return -EINVAL;
+ }
+ pinfo->brg = *data;
+ }
data = of_get_property(np, "fsl,cpm-command", &len);
if (!data || len != 4) {