[RFC,1/5] rtc-at91rm9200: add configuration support

Commit Message

Johan Hovold March 29, 2013, 4:03 p.m. UTC

Add configuration support which can be used to implement SoC-specific
workarounds for broken hardware.
---
 drivers/rtc/rtc-at91rm9200.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Comments

Johan Hovold March 29, 2013, 4:12 p.m. UTC | #1

On Fri, Mar 29, 2013 at 05:03:46PM +0100, Johan Hovold wrote:
> Add device tree support.
> ---
>  drivers/rtc/rtc-at91rm9200.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
> index 5bae0a1..67260f9 100644
> --- a/drivers/rtc/rtc-at91rm9200.c
> +++ b/drivers/rtc/rtc-at91rm9200.c
> @@ -28,6 +28,7 @@
>  #include <linux/ioctl.h>
>  #include <linux/completion.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
>  
>  #include <asm/uaccess.h>
>  
> @@ -255,9 +256,30 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
>  static const struct at91_rtc_config at91rm9200_config = {
>  };
>  
> +#if defined(CONFIG_OF)
> +static const struct of_device_id at91_rtc_dt_ids[] = {
> +	{
> +		.compatible = "atmel,at91rm9200-rtc",
> +		.data = &at91rm9200_config,
>+	},

There's a missing brace here. Will fix after any further feedback.

> +		/* terminator */
> +	}
> +};
> +MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
> +#endif

Douglas Gilbert March 29, 2013, 4:39 p.m. UTC | #2

On 13-03-29 12:03 PM, Johan Hovold wrote:
> Add support for the at91sam9x5-family which must use the shadow
> interrupt mask due to a hardware issue.
> ---
>   drivers/rtc/rtc-at91rm9200.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
> index 2921866..f3e351f 100644
> --- a/drivers/rtc/rtc-at91rm9200.c
> +++ b/drivers/rtc/rtc-at91rm9200.c
> @@ -318,12 +318,20 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
>   static const struct at91_rtc_config at91rm9200_config = {
>   };
>
> +static const struct at91_rtc_config at91sam9x5_config = {
> +	.use_shadow_imr = true,
> +};
> +
>   #if defined(CONFIG_OF)
>   static const struct of_device_id at91_rtc_dt_ids[] = {
>   	{
>   		.compatible = "atmel,at91rm9200-rtc",
>   		.data = &at91rm9200_config,
>   	},
> +	{
> +		.compatible = "atmel,at91sam9x5-rtc",
> +		.data = &at91sam9x5_config,
> +	},
>   		/* terminator */
>   	}
>   };
>

Johan,
Looks good.

Plus add something like this to at91sam9x5.dtsi after the
i2c@2 entry (at the end):

         rtc {
                 compatible = "atmel,at91sam9x5-rtc";
                 reg = <0xfffffeb0 0x40>;
                 interrupts = <1 4 7>;
                 status = "disabled";
         };


and an "enabler" in ariag25.dts (and perhaps other members
of the 9x5 sub-family), also at the end:

         rtc {
                 status = "okay";
         };

My patches are in Robert Nelson's tree at:
    http://www.eewiki.net/display/linuxonarm/AT91SAM9x5
in the Linux kernel section. My RTC code amounts to the same
thing as you are proposing, without the safety code around
the IMR shadow.

I provide binaries based on that work to Aria G25 users
via a google group. No-one has complained about RTC not
working. SPI and I2C problems are on-going but gradually
being sorted. Hence I know people are using and testing
this code, other than me.

Doug Gilbert

Patch

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index 434ebc3..5bae0a1 100644
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -40,6 +40,10 @@ 
 
 #define AT91_RTC_EPOCH		1900UL	/* just like arch/arm/common/rtctime.c */
 
+struct at91_rtc_config {
+};
+
+static const struct at91_rtc_config *at91_rtc_config;
 static DECLARE_COMPLETION(at91_rtc_updated);
 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
 static void __iomem *at91_rtc_regs;
@@ -248,6 +252,15 @@  static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 	return IRQ_NONE;		/* not handled */
 }
 
+static const struct at91_rtc_config at91rm9200_config = {
+};
+
+static const struct at91_rtc_config *
+at91_rtc_get_config(struct platform_device *pdev)
+{
+	return &at91rm9200_config;
+}
+
 static const struct rtc_class_ops at91_rtc_ops = {
 	.read_time	= at91_rtc_readtime,
 	.set_time	= at91_rtc_settime,
@@ -266,6 +279,10 @@  static int __init at91_rtc_probe(struct platform_device *pdev)
 	struct resource *regs;
 	int ret = 0;
 
+	at91_rtc_config = at91_rtc_get_config(pdev);
+	if (!at91_rtc_config)
+		return -ENODEV;
+
 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!regs) {
 		dev_err(&pdev->dev, "no mmio resource defined\n");