serial: 8250_dw: add support for clk api

Commit Message

Maxime Ripard March 19, 2013, 10:52 a.m. UTC

From: Emilio López <[e-mail]>

This commit implements support for using the clk api; this lets us use
the "clocks" property with device tree, instead of having to use
clock-frequency.

Signed-off-by: Emilio López <[e-mail]>
---
 drivers/tty/serial/8250/8250_dw.c |   33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

Comments

Heikki Krogerus March 21, 2013, 8:47 a.m. UTC | #1

On Tue, Mar 19, 2013 at 11:52:49AM +0100, Maxime Ripard wrote:
> From: Emilio López <[e-mail]>
> 
> This commit implements support for using the clk api; this lets us use
> the "clocks" property with device tree, instead of having to use
> clock-frequency.
> 
> Signed-off-by: Emilio López <[e-mail]>

FWIW,

Reviewed-by: Heikki Krogerus <[e-mail]>

Maxime Ripard March 26, 2013, 10:35 a.m. UTC | #2

Hi Greg,

Le 21/03/2013 09:47, Heikki Krogerus a écrit :
> On Tue, Mar 19, 2013 at 11:52:49AM +0100, Maxime Ripard wrote:
>> From: Emilio López <[e-mail]>
>>
>> This commit implements support for using the clk api; this lets us use
>> the "clocks" property with device tree, instead of having to use
>> clock-frequency.
>>
>> Signed-off-by: Emilio López <[e-mail]>
> 
> FWIW,
> 
> Reviewed-by: Heikki Krogerus <[e-mail]>

Would you consider merging this patch, or do you have additional comments?

We have several patch series that depends on this one that I'd like to
see included in 3.10, and we begin to see the end of the 3.9 release cycle.

Thanks,
Maxime

Greg KH March 26, 2013, 11:34 p.m. UTC | #3

On Tue, Mar 26, 2013 at 11:35:18AM +0100, Maxime Ripard wrote:
> Hi Greg,
> 
> Le 21/03/2013 09:47, Heikki Krogerus a écrit :
> > On Tue, Mar 19, 2013 at 11:52:49AM +0100, Maxime Ripard wrote:
> >> From: Emilio López <[e-mail]>
> >>
> >> This commit implements support for using the clk api; this lets us use
> >> the "clocks" property with device tree, instead of having to use
> >> clock-frequency.
> >>
> >> Signed-off-by: Emilio López <[e-mail]>
> > 
> > FWIW,
> > 
> > Reviewed-by: Heikki Krogerus <[e-mail]>
> 
> Would you consider merging this patch, or do you have additional comments?
> 
> We have several patch series that depends on this one that I'd like to
> see included in 3.10, and we begin to see the end of the 3.9 release cycle.

You resent one patch, in the middle of a 7 patch series, with me on the
 cc: and somehow expected me to know that I was supposed to apply it?

Please be specific and realistic with your requests.

Resend it if you feel I should apply it.

greg k-h

Patch

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index db0e66f..3dedd24 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -26,6 +26,7 @@ 
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
+#include <linux/clk.h>
 
 #include "8250.h"
 
@@ -55,8 +56,9 @@ 
 
 
 struct dw8250_data {
-	int	last_lcr;
-	int	line;
+	int		last_lcr;
+	int		line;
+	struct clk	*clk;
 };
 
 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
@@ -136,8 +138,13 @@  static int dw8250_probe_of(struct uart_port *p)
 	if (!of_property_read_u32(np, "reg-shift", &val))
 		p->regshift = val;
 
+	/* clock got configured through clk api, all done */
+	if (p->uartclk)
+		return 0;
+
+	/* try to find out clock frequency from DT as fallback */
 	if (of_property_read_u32(np, "clock-frequency", &val)) {
-		dev_err(p->dev, "no clock-frequency property set\n");
+		dev_err(p->dev, "clk or clock-frequency not defined\n");
 		return -EINVAL;
 	}
 	p->uartclk = val;
@@ -294,9 +301,20 @@  static int dw8250_probe(struct platform_device *pdev)
 	if (!uart.port.membase)
 		return -ENOMEM;
 
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(data->clk)) {
+		clk_prepare_enable(data->clk);
+		uart.port.uartclk = clk_get_rate(data->clk);
+	}
+
 	uart.port.iotype = UPIO_MEM;
 	uart.port.serial_in = dw8250_serial_in;
 	uart.port.serial_out = dw8250_serial_out;
+	uart.port.private_data = data;
 
 	dw8250_setup_port(&uart);
 
@@ -312,12 +330,6 @@  static int dw8250_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	uart.port.private_data = data;
-
 	data->line = serial8250_register_8250_port(&uart);
 	if (data->line < 0)
 		return data->line;
@@ -333,6 +345,9 @@  static int dw8250_remove(struct platform_device *pdev)
 
 	serial8250_unregister_port(data->line);
 
+	if (!IS_ERR(data->clk))
+		clk_disable_unprepare(data->clk);
+
 	return 0;
 }