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path: root/drivers/serial/amba-pl010.c
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Diffstat (limited to 'drivers/serial/amba-pl010.c')
-rw-r--r--drivers/serial/amba-pl010.c39
1 files changed, 37 insertions, 2 deletions
diff --git a/drivers/serial/amba-pl010.c b/drivers/serial/amba-pl010.c
index ea49aafd66bf..1a9a24b82636 100644
--- a/drivers/serial/amba-pl010.c
+++ b/drivers/serial/amba-pl010.c
@@ -48,6 +48,7 @@
#include <linux/serial.h>
#include <linux/amba/bus.h>
#include <linux/amba/serial.h>
+#include <linux/clk.h>
#include <asm/io.h>
@@ -70,6 +71,7 @@
*/
struct uart_amba_port {
struct uart_port port;
+ struct clk *clk;
struct amba_device *dev;
struct amba_pl010_data *data;
unsigned int old_status;
@@ -313,11 +315,20 @@ static int pl010_startup(struct uart_port *port)
int retval;
/*
+ * Try to enable the clock producer.
+ */
+ retval = clk_enable(uap->clk);
+ if (retval)
+ goto out;
+
+ uap->port.uartclk = clk_get_rate(uap->clk);
+
+ /*
* Allocate the IRQ
*/
retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
if (retval)
- return retval;
+ goto clk_dis;
/*
* initialise the old status of the modem signals
@@ -331,6 +342,11 @@ static int pl010_startup(struct uart_port *port)
uap->port.membase + UART010_CR);
return 0;
+
+ clk_dis:
+ clk_disable(uap->clk);
+ out:
+ return retval;
}
static void pl010_shutdown(struct uart_port *port)
@@ -351,6 +367,11 @@ static void pl010_shutdown(struct uart_port *port)
writel(readb(uap->port.membase + UART010_LCRH) &
~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
uap->port.membase + UART010_LCRH);
+
+ /*
+ * Shut down the clock producer
+ */
+ clk_disable(uap->clk);
}
static void
@@ -540,6 +561,8 @@ pl010_console_write(struct console *co, const char *s, unsigned int count)
struct uart_amba_port *uap = amba_ports[co->index];
unsigned int status, old_cr;
+ clk_enable(uap->clk);
+
/*
* First save the CR then disable the interrupts
*/
@@ -557,6 +580,8 @@ pl010_console_write(struct console *co, const char *s, unsigned int count)
barrier();
} while (status & UART01x_FR_BUSY);
writel(old_cr, uap->port.membase + UART010_CR);
+
+ clk_disable(uap->clk);
}
static void __init
@@ -605,6 +630,8 @@ static int __init pl010_console_setup(struct console *co, char *options)
if (!uap)
return -ENODEV;
+ uap->port.uartclk = clk_get_rate(uap->clk);
+
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
@@ -666,12 +693,17 @@ static int pl010_probe(struct amba_device *dev, void *id)
goto free;
}
+ uap->clk = clk_get(&dev->dev, "UARTCLK");
+ if (IS_ERR(uap->clk)) {
+ ret = PTR_ERR(uap->clk);
+ goto unmap;
+ }
+
uap->port.dev = &dev->dev;
uap->port.mapbase = dev->res.start;
uap->port.membase = base;
uap->port.iotype = UPIO_MEM;
uap->port.irq = dev->irq[0];
- uap->port.uartclk = 14745600;
uap->port.fifosize = 16;
uap->port.ops = &amba_pl010_pops;
uap->port.flags = UPF_BOOT_AUTOCONF;
@@ -686,6 +718,8 @@ static int pl010_probe(struct amba_device *dev, void *id)
if (ret) {
amba_set_drvdata(dev, NULL);
amba_ports[i] = NULL;
+ clk_put(uap->clk);
+ unmap:
iounmap(base);
free:
kfree(uap);
@@ -708,6 +742,7 @@ static int pl010_remove(struct amba_device *dev)
amba_ports[i] = NULL;
iounmap(uap->port.membase);
+ clk_put(uap->clk);
kfree(uap);
return 0;
}