[PATCH] rtc: rtc-twl: fix initialization sequence

[PATCH] rtc: rtc-twl: fix initialization sequence

[Grygorii Strashko]

The twl-rtc has the following dependencies from other drivers during the boot:
pinctrl
|-i2c-omap
  |- twl-core
     |- twl-rtc

The i2c-omap probe may be deferred because pinctrl iss not ready yet. As result,
i2c-omap will be probed at late init time. Which, in turn, will delay twl-core
initialization till late init time too.

But, the twl-rtc driver is registered from finction twl_rtc_init() at
module(device) init time and contains part of its initialization code within it.
Unfortunatelly, this code depends on twl-core which may be not ready at that
moment and, as result, wrong register map will be selected
(on OMAP3 twl6030_rtc_reg_map will be selected instead of twl4030_rtc_reg_map).

static int __init twl_rtc_init(void)
{
    if (twl_class_is_4030()) <--- twl-core might be not ready here
                             <--- and twl_class_is_4030() will return 0
        rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
    else
        rtc_reg_map = (u8 *) twl6030_rtc_reg_map;

    return platform_driver_register(&twl4030rtc_driver);
}

Hence, move register map selection code in twl_rtc_probe() to solve this issue.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 drivers/rtc/rtc-twl.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
index bbda0fd..1698115 100644
--- a/drivers/rtc/rtc-twl.c
+++ b/drivers/rtc/rtc-twl.c
@@ -481,6 +481,11 @@ static int twl_rtc_probe(struct platform_device *pdev)
 	if (irq <= 0)
 		goto out1;
 
+	if (twl_class_is_4030())
+		rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
+	else
+		rtc_reg_map = (u8 *) twl6030_rtc_reg_map;
+
 	ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
 	if (ret < 0)
 		goto out1;
@@ -622,11 +627,6 @@ static struct platform_driver twl4030rtc_driver = {
 
 static int __init twl_rtc_init(void)
 {
-	if (twl_class_is_4030())
-		rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
-	else
-		rtc_reg_map = (u8 *) twl6030_rtc_reg_map;
-
 	return platform_driver_register(&twl4030rtc_driver);
 }
 module_init(twl_rtc_init);
-- 
1.7.9.5

Re: [PATCH] rtc: rtc-twl: fix initialization sequence

[Grygorii Strashko]

Pls, ignore this patch. It duplicates:

https://patchwork.kernel.org/patch/2448251/ - [v2,1/2] RTC: rtc-twl: Fix 
rtc_reg_map initialization
from Peter Ujfalusi

On 06/05/2013 02:19 PM, Grygorii Strashko wrote:
> The twl-rtc has the following dependencies from other drivers during the boot:
> pinctrl
> |-i2c-omap
>    |- twl-core
>       |- twl-rtc
>
> The i2c-omap probe may be deferred because pinctrl iss not ready yet. As result,
> i2c-omap will be probed at late init time. Which, in turn, will delay twl-core
> initialization till late init time too.
>
> But, the twl-rtc driver is registered from finction twl_rtc_init() at
> module(device) init time and contains part of its initialization code within it.
> Unfortunatelly, this code depends on twl-core which may be not ready at that
> moment and, as result, wrong register map will be selected
> (on OMAP3 twl6030_rtc_reg_map will be selected instead of twl4030_rtc_reg_map).
>
> static int __init twl_rtc_init(void)
> {
>      if (twl_class_is_4030()) <--- twl-core might be not ready here
>                               <--- and twl_class_is_4030() will return 0
>          rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
>      else
>          rtc_reg_map = (u8 *) twl6030_rtc_reg_map;
>
>      return platform_driver_register(&twl4030rtc_driver);
> }
>
> Hence, move register map selection code in twl_rtc_probe() to solve this issue.
>
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
> ---
>   drivers/rtc/rtc-twl.c |   10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
> index bbda0fd..1698115 100644
> --- a/drivers/rtc/rtc-twl.c
> +++ b/drivers/rtc/rtc-twl.c
> @@ -481,6 +481,11 @@ static int twl_rtc_probe(struct platform_device *pdev)
>   	if (irq <= 0)
>   		goto out1;
>   
> +	if (twl_class_is_4030())
> +		rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
> +	else
> +		rtc_reg_map = (u8 *) twl6030_rtc_reg_map;
> +
>   	ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
>   	if (ret < 0)
>   		goto out1;
> @@ -622,11 +627,6 @@ static struct platform_driver twl4030rtc_driver = {
>   
>   static int __init twl_rtc_init(void)
>   {
> -	if (twl_class_is_4030())
> -		rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
> -	else
> -		rtc_reg_map = (u8 *) twl6030_rtc_reg_map;
> -
>   	return platform_driver_register(&twl4030rtc_driver);
>   }
>   module_init(twl_rtc_init);