From: Laurent Pinchart <laurentp@cse-semaphore.com>
Date: Mon, 28 Jul 2008 08:42:16 +0000 (+0200)
Subject: cpm_uart: Add generic clock API support to set baudrates
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=80776554b6c93cf828ddc702010c6a189aa0d0e9;p=linux-beck.git

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 18a71839dc9e..4c900efa164e 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -283,6 +283,7 @@ config FSL_ULI1575
 
 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 5999ef5ac78e..7274b527a3c1 100644
--- a/drivers/serial/cpm_uart/cpm_uart.h
+++ b/drivers/serial/cpm_uart/cpm_uart.h
@@ -77,6 +77,7 @@ struct uart_cpm_port {
 	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 5e0c17f71653..25efca5a7a1f 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 @@ static void cpm_uart_set_termios(struct uart_port *port,
 		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 @@ static int cpm_uart_init_port(struct device_node *np,
 	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;
+	}
+	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;
 	}
-	pinfo->brg = *data;
 
 	data = of_get_property(np, "fsl,cpm-command", &len);
 	if (!data || len != 4) {