On 04/02/2013 10:55 AM, Christoph Fritz wrote:
> On Mon, 2013-04-01 at 22:05 +0200, Javier Martinez Canillas wrote:
>
>>> As a quick-fix (hack) I wrote directly to the registers in gpio_probe()
>>> to enable GPIO banks. I now geht this:
>>>
>>>>> [ 0.214630] omap_gpio_probe, 1133, CM_CLKSEL_PER 0x48005040: 0x000000ff
>>>>> [ 0.214660] omap_gpio_probe, 1136, CM_ICLKEN_PER 0x48005010: 0x0007ffff
>>>>> [ 0.214660] omap_gpio_probe, 1139, CM_FCLKEN_PER 0x48005000: 0x0007ffff
>
> to be more specific on this point, this is the patch to enable the
> gpio-clocks:
>
> --
> Subject: [PATCH] HACK: enable gpio-clocks in gpio-omap probe()
>
> Without this patch setting trigger value from #interrupt-cell two
> (smsc911x) fails.
> ---
> drivers/gpio/gpio-omap.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index 159f5c5..720b2e6 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -1098,6 +1098,7 @@ static int omap_gpio_probe(struct platform_device
> *pdev)
> struct resource *res;
> struct gpio_bank *bank;
> int ret = 0;
> + void __iomem *tmp;
>
> match = of_match_device(of_match_ptr(omap_gpio_match), dev);
>
> @@ -1117,6 +1118,17 @@ static int omap_gpio_probe(struct platform_device
> *pdev)
> return -ENODEV;
> }
>
> + // TRM: Table 3-242. PER_CM Register Summary
> + tmp = ioremap(0x48005040, 4); //CM_CLKSEL_PER, GPT2 = sys clk
> + writel(0xFF, tmp);
> + iounmap(tmp);
> + tmp = ioremap(0x48005010, 4); //CM_ICLKEN_PER, ICKen GPT2
> + writel(0x7FFFF, tmp);
> + iounmap(tmp);
> + tmp = ioremap(0x48005000, 4); //CM_FCLKEN_PER, GPIOX functional clock
> is enabled
> + writel(0x7FFFF, tmp);
> + iounmap(tmp);
> +
> bank->irq = res->start;
> bank->dev = dev;
> bank->dbck_flag = pdata->dbck_flag;
>
> Is there a better way to do this?
A better way to hack this and leave the gpio bank on always would be ...
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index f1fbedb2..0fc75a2 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1181,8 +1181,6 @@ static int omap_gpio_probe(struct platform_device *pdev)
if (bank->loses_context)
bank->get_context_loss_count = pdata->get_context_loss_count;
- pm_runtime_put(bank->dev);
-
list_add_tail(&bank->node, &omap_gpio_list);
return ret;
>>> And it works for me. _But_ when I do enable regulator twl4030
>>> (CONFIG_REGULATOR_TWL4030=y) in my config these registers get reset:
>>>
>>> [ 2.935455] smsc911x_open, 1537, CM_CLKSEL_PER 0x48005040: 0x000000ff
>>> [ 2.942291] smsc911x_open, 1540, CM_ICLKEN_PER 0x48005010: 0x00040fff
>>> [ 2.949066] smsc911x_open, 1543, CM_FCLKEN_PER 0x48005000: 0x00000000
>>>
>>> And the IRQ source for the network chip (smsc911x) is disabled :-(
>
> CONFIG_REGULATOR_TWL4030=y disables the gpio-clocks. Why is that?
Well your hack is completely by-passing pm-runtime and so pm-runtime does not
know that someone has enabled the bank. Therefore, the next time
pm_runtime_get()
is called followed by a pm_runtime_put() for the gpio bank it will disable the
bank. By removing the pm_runtime_put() at the end of probe should always keep
the
bank enabled.
>>> Do you have any idea how to ("quick") fix this?
>>>
>>
>> A quick hack is to call gpio_request() explicitly before calling to
>> irq_set_type() is made.
>> I've this patch just to make it work until we find a clean solution:
>>
>> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
>> index 90c15ee..d594e1d 100644
>> --- a/arch/arm/mach-omap2/gpmc.c
>> +++ b/arch/arm/mach-omap2/gpmc.c
>> @@ -14,6 +14,7 @@
>> */
>> #undef DEBUG
>>
>> +#include <linux/gpio.h>
>> #include <linux/irq.h>
>> #include <linux/kernel.h>
>> #include <linux/init.h>
>> @@ -1528,6 +1529,11 @@ static int gpmc_probe_dt(struct platform_device *pdev)
>> return ret;
>> }
>>
>> + ret = gpio_request_one(176, GPIOF_IN, "smsc911x irq");
>> + if (ret) {
>> + pr_err("Failed to request IRQ GPIO%d\n", 176);
>> + return ret;
>> + }
>> +
>> for_each_node_by_name(child, "nand") {
>> ret = gpmc_probe_nand_child(pdev, child);
>> if (ret < 0) {
>>
>> This solves the issue of the non-initialized GPIO bank before that
>> makes the kernel to hang.
>
> Here it does not. A printk shows that I'm not using gpmc at all.
> So I added a gpmc node:
>
> + gpmc: gpmc@0x6E000000 {
> + compatible = "ti,omap3430-gpmc";
> + ti,hwmods = "ti,gpmc";
This should just be ...
+ ti,hwmods = "gpmc";
> + reg = <0x6E000000 0x2000>;
> + gpmc,num-cs = <8>;
> + gpmc,num-waitpins = <2>;
> + #address-cells = <2>;
> + #size-cells = <1>;
> + ranges = <0 0 0x0 0x3FFFFFFF>;
> +
> + };
>
> But still, gpmc_probe_dt() isn't called. I maybe have to define some
> child nodes but currently I do configure the gpmc in u-boot and try to
> avoid kernel-gpmc-config.
Not sure what patches you have, but the plan for DT is that the kernel
configures the gpmc and is not dependent on the bootloader.
Cheers
Jon
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