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[ARM] Convert AMBA PL010 driver to use the clk infrastructure 

Convert the AMBA PL010 serial driver to use the clock infrastructure
to allow EP93xx platforms to properly gate the clock to the UARTs.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2007-04-22 12:30:41 +01:00 committed by Russell King
parent 1b0646a033
commit ed519dede3
2 changed files with 42 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/arm/mach-ep93xx/clock.c
View File

@ -27,6 +27,10 @@ struct clk {
u32 enable_mask;
};
static struct clk clk_uart = {
.name = "UARTCLK",
.rate = 14745600,
};
static struct clk clk_pll1 = {
.name = "pll1",
};
@ -50,6 +54,7 @@ static struct clk clk_usb_host = {
static struct clk *clocks[] = {
&clk_uart,
&clk_pll1,
&clk_f,
&clk_h,

39
drivers/serial/amba-pl010.c
View File

@ -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;
@ -312,12 +314,21 @@ static int pl010_startup(struct uart_port *port)
struct uart_amba_port *uap = (struct uart_amba_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;
}