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

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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
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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;
}