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SubjectRe: [PATCH v4 3/6] gpio: davinci: use irqdomain
Hi grygorii,

Thanks for the review.

On Mon, Nov 4, 2013 at 11:57 PM, Grygorii Strashko
<grygorii.strashko@ti.com> wrote:
> Hi Prabhakar Lad,
>
> On 11/02/2013 05:39 PM, Lad, Prabhakar wrote:
>> From: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
>>
>> This patch converts the davinci gpio driver to use irqdomain
>> support.
>
> This patch needs to be splitted in two:
> 1) add IRQ domain support
> 2) remove intc_irq_num
>
OK

>>
>> Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>> ---
>> arch/arm/mach-davinci/da830.c | 1 -
>> arch/arm/mach-davinci/da850.c | 1 -
>> arch/arm/mach-davinci/dm355.c | 1 -
>> arch/arm/mach-davinci/dm365.c | 1 -
>> arch/arm/mach-davinci/dm644x.c | 1 -
>> arch/arm/mach-davinci/dm646x.c | 1 -
>> drivers/gpio/gpio-davinci.c | 49 ++++++++++++++++++----------
>> include/linux/platform_data/gpio-davinci.h | 3 +-
>> 8 files changed, 32 insertions(+), 26 deletions(-)
>>
>
> [...]
>
>>
>> int __init dm646x_gpio_register(void)
>> diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
>> index 95c6df1..bcb6d8d 100644
>> --- a/drivers/gpio/gpio-davinci.c
>> +++ b/drivers/gpio/gpio-davinci.c
>> @@ -16,6 +16,7 @@
>> #include <linux/err.h>
>> #include <linux/io.h>
>> #include <linux/irq.h>
>> +#include <linux/irqdomain.h>
>> #include <linux/platform_device.h>
>> #include <linux/platform_data/gpio-davinci.h>
>>
>> @@ -292,7 +293,7 @@ gpio_irq_handler(unsigned irq, struct irq_desc *desc)
>> __raw_writel(status, &g->intstat);
>>
>> /* now demux them to the right lowlevel handler */
>> - n = d->irq_base;
>> + n = irq_find_mapping(d->irq_domain, 0);
>
> Sorry, but I don't understand why have you used <0> as hwirq?
>
> All below logic may not work in case if we switch to use Linear IRQ domain :(
> - irq_create_mapping() may return ANY Linux IRQ number. It means, for
> example, for bank0(ngpio=32)[0] it may return Linux_IRQ=200 or 201 or any other.
> Also, for bank3(ngpio=16)[0] it may return Linux_IRQ=150, etc.
> - More over, if you call irq_create_mapping() 32 times you may NOT get
> sequential Linux_IRQ numbers.
>
> So, the better sequence here can be smth. as below
> (I can't verify it - my HW support only unbanked IRQs):
>
Yeah below logic works fine for banked IRQs.

> if (irq & 1)
> mask <<= 16;
>
> while (1) {
> u32 status;
> int bit;
>
> /* ack any irqs */
> status = __raw_readl(&g->intstat) & mask;
> if (!status)
> break;
> __raw_writel(status, &g->intstat);
>
> /* now demux them to the right lowlevel handler */
> while (status) {
> bit = __ffs(status);
> status &= ~(1 << bit);
> generic_handle_irq(irq_find_mapping(d->irq_domain, bit));
> }
> }
>
>
>> if (irq & 1) {
>> n += 16;
>> status >>= 16;
>> @@ -313,10 +314,7 @@ static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
>> {
>> struct davinci_gpio_controller *d = chip2controller(chip);
>>
>> - if (d->irq_base >= 0)
>> - return d->irq_base + offset;
>> - else
>> - return -ENODEV;
>> + return irq_find_mapping(d->irq_domain, offset);
>
> I think you can use irq_create_mapping() here instead of
> irq_find_mapping(), so IRQ will be mapped/allocated on demand.
> Also, it seems, above code may crash in case if SoC has >1 GPIO banks and
> gpio_unbanked > 0 and someone will call gpio_to_irq(>31).
>
Fixed it.

>> }
>>
>> static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
>> @@ -373,6 +371,7 @@ static int davinci_gpio_irq_setup(struct platform_device *pdev)
>> struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
>> struct davinci_gpio_platform_data *pdata = dev->platform_data;
>> struct davinci_gpio_regs __iomem *g;
>> + int gpio_irq = 0;
>>
>> ngpio = pdata->ngpio;
>> res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>> @@ -402,9 +401,15 @@ static int davinci_gpio_irq_setup(struct platform_device *pdev)
>> */
>> for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
>> chips[bank].chip.to_irq = gpio_to_irq_banked;
>> - chips[bank].irq_base = pdata->gpio_unbanked
>> - ? -EINVAL
>> - : (pdata->intc_irq_num + gpio);
>> + if (!pdata->gpio_unbanked) {
>> + chips[bank].irq_domain =
>> + irq_domain_add_linear(NULL, 32,
>
> Use chips[i].chip.ngpio here instead of const 32?
>
OK

>> + &irq_domain_simple_ops,
>
> Pass &davinci_gpio_irq_ops (see below)
>
>> + NULL);
>
> Pass &chips[bank] as host_data and use .map() callback (see below)
>
OK

>> +
>> + if (!chips[bank].irq_domain)
>> + return -ENOMEM;
>> + }
>> }
>>
>> /*
>> @@ -445,9 +450,7 @@ static int davinci_gpio_irq_setup(struct platform_device *pdev)
>> * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
>> * then chain through our own handler.
>> */
>> - for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
>> - gpio < ngpio;
>> - bank++, bank_irq++) {
>> + for (gpio = 0, irq = 0, bank = 0; gpio < ngpio; bank++, bank_irq++) {
>> unsigned i;
>>
>> /* disabled by default, enabled only as needed */
>> @@ -465,12 +468,22 @@ static int davinci_gpio_irq_setup(struct platform_device *pdev)
>> */
>> irq_set_handler_data(bank_irq, &chips[gpio / 32]);
>>
>> - for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
>> - irq_set_chip(irq, &gpio_irqchip);
>> - irq_set_chip_data(irq, (__force void *)g);
>> - irq_set_handler_data(irq, (void *)__gpio_mask(gpio));
>> - irq_set_handler(irq, handle_simple_irq);
>> - set_irq_flags(irq, IRQF_VALID);
>> + if (!(bank % 2))
>> + irq = 0;
>> + else
>> + irq = 16;
>
> As I mentioned above, I think, it is not good to play with IRQ numbers here.
> Only chained IRQs and <binten> can be configured in this cycle.
>
Done

>> +
>> + for (i = 0; i < 16 && gpio < ngpio; i++, gpio++) {
>> + int irqno =
>> + irq_create_mapping(chips[gpio / 32].irq_domain,
>> + i + irq);
>> +
>> + irq_set_chip(irqno, &gpio_irqchip);
>> + irq_set_chip_data(irqno, (__force void *)g);
>> + irq_set_handler_data(irqno, (void *)__gpio_mask(gpio));
>> + irq_set_handler(irqno, handle_simple_irq);
>> + set_irq_flags(irqno, IRQF_VALID);
>
> It makes no sense to manually create mapping. Usually it can be done in
> .map() callback of IRQ domain. Like:
>
> static int davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
> irq_hw_number_t hw)
> {
> struct davinci_gpio_controller *chip = d->host_data;
> unsigned gpio = chip->chip.base + hw;
>
> irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
> "davinci_gpio");
> irq_set_irq_type(irq, IRQ_TYPE_NONE);
> set_irq_flags(irq, IRQF_VALID);
> ...
> return 0;
> }
>
> static const struct irq_domain_ops davinci_gpio_irq_ops = {
> .map = davinci_gpio_irq_map,
> .xlate = irq_domain_xlate_onetwocell,
> };
>
>
Fixed it.

Regards,
--Prabhakar Lad


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