Re: [PATCH v5 1/3] gpio: xgene: Enable X-Gene standby GPIO as interrupt controller

Quan Nguyen
2016-02-11T16:35:36Z

On Wed, Feb 10, 2016 at 10:09 PM, Marc Zyngier <marc.zyngier-5wv7dgnIgG8@public.gmane.org> wrote:
> Quan,
>
> This is getting better. Some comments below.
>
> On 29/01/16 04:28, Quan Nguyen wrote:
>> Enable X-Gene standby GPIO controller as interrupt controller to provide
>> its own resources. This avoids ambiguity where GIC interrupt resource is
>> use as X-Gene standby GPIO interrupt resource in user driver.
>>
>> Signed-off-by: Y Vo <yvo-qTEPVZfXA3Y@public.gmane.org>
>> Signed-off-by: Quan Nguyen <qnguyen-qTEPVZfXA3Y@public.gmane.org>
>> ---
>> drivers/gpio/gpio-xgene-sb.c | 275 ++++++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 243 insertions(+), 32 deletions(-)
>>
>> diff --git a/drivers/gpio/gpio-xgene-sb.c b/drivers/gpio/gpio-xgene-sb.c
>> index 282004d..026da90 100644
>> --- a/drivers/gpio/gpio-xgene-sb.c
>> +++ b/drivers/gpio/gpio-xgene-sb.c
>> @@ -2,8 +2,9 @@
>> * AppliedMicro X-Gene SoC GPIO-Standby Driver
>> *
>> * Copyright (c) 2014, Applied Micro Circuits Corporation
>> - * Author: Tin Huynh <tnhuynh-qTEPVZfXA3Y@public.gmane.org>.
>> - * Y Vo <yvo-qTEPVZfXA3Y@public.gmane.org>.
>> + * Author: Tin Huynh <tnhuynh-qTEPVZfXA3Y@public.gmane.org>.
>> + * Y Vo <yvo-qTEPVZfXA3Y@public.gmane.org>.
>> + * Quan Nguyen <qnguyen-qTEPVZfXA3Y@public.gmane.org>.
>> *
>> * This program is free software; you can redistribute it and/or modify it
>> * under the terms of the GNU General Public License as published by the
>> @@ -28,9 +29,14 @@
>>
>> #include "gpiolib.h"
>>
>> -#define XGENE_MAX_GPIO_DS 22
>> -#define XGENE_MAX_GPIO_DS_IRQ 6
>> +/* Common property names */
>> +#define XGENE_NIRQ_PROPERTY "apm,nr-irqs"
>> +#define XGENE_NGPIO_PROPERTY "apm,nr-gpios"
>> +#define XGENE_IRQ_START_PROPERTY "apm,irq-start"
>>
>> +#define XGENE_DFLT_MAX_NGPIO 22
>> +#define XGENE_DFLT_MAX_NIRQ 6
>> +#define XGENE_DFLT_IRQ_START_PIN 8
>> #define GPIO_MASK(x) (1U << ((x) % 32))
>>
>> #define MPA_GPIO_INT_LVL 0x0290
>> @@ -39,19 +45,32 @@
>> #define MPA_GPIO_IN_ADDR 0x02a4
>> #define MPA_GPIO_SEL_LO 0x0294
>>
>> +#define GPIO_INT_LEVEL_H 0x000001
>> +#define GPIO_INT_LEVEL_L 0x000000
>> +
>> /**
>> * struct xgene_gpio_sb - GPIO-Standby private data structure.
>> * @gc: memory-mapped GPIO controllers.
>> - * @irq: Mapping GPIO pins and interrupt number
>> - * nirq: Number of GPIO pins that supports interrupt
>> + * @regs: GPIO register base offset
>> + * @irq_domain: GPIO interrupt domain
>> + * @irq_start: GPIO pin that start support interrupt
>> + * @nirq: Number of GPIO pins that supports interrupt
>> + * @parent_irq_base: Start parent HWIRQ
>> */
>> struct xgene_gpio_sb {
>> struct gpio_chip gc;
>> - u32 *irq;
>> - u32 nirq;
>> + void __iomem *regs;
>> + struct irq_domain *irq_domain;
>> + u16 irq_start;
>> + u16 nirq;
>> + u16 parent_irq_base;
>> };
>>
>> -static void xgene_gpio_set_bit(struct gpio_chip *gc, void __iomem *reg, u32 gpio, int val)
>> +#define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
>> +#define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)
>> +
>> +static void xgene_gpio_set_bit(struct gpio_chip *gc,
>> + void __iomem *reg, u32 gpio, int val)
>> {
>> u32 data;
>>
>> @@ -63,23 +82,180 @@ static void xgene_gpio_set_bit(struct gpio_chip *gc, void __iomem *reg, u32 gpio
>> gc->write_reg(reg, data);
>> }
>>
>> -static int apm_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
>> +static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
>> +{
>> + struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
>> + int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
>> + int lvl_type = GPIO_INT_LEVEL_H;
>> +
>> + switch (type & IRQ_TYPE_SENSE_MASK) {
>> + case IRQ_TYPE_EDGE_RISING:
>> + case IRQ_TYPE_LEVEL_HIGH:
>> + lvl_type = GPIO_INT_LEVEL_H;
>> + break;
>> + case IRQ_TYPE_EDGE_FALLING:
>> + case IRQ_TYPE_LEVEL_LOW:
>> + lvl_type = GPIO_INT_LEVEL_L;
>> + break;
>> + default:
>> + break;
>> + }
>> +
>> + xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
>> + gpio * 2, 1);
>> + xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
>> + d->hwirq, lvl_type);
>> +
>> + /* Propagate IRQ type setting to parent */
>> + if (type & IRQ_TYPE_EDGE_BOTH)
>> + return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
>> + else
>> + return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
>> +}
>> +
>> +static void xgene_gpio_sb_irq_shutdown(struct irq_data *d)
>> +{
>> + struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
>> +
>> + gpiochip_unlock_as_irq(&priv->gc, HWIRQ_TO_GPIO(priv, d->hwirq));
>> +}
>> +
>> +static struct irq_chip xgene_gpio_sb_irq_chip = {
>> + .name = "sbgpio",
>> + .irq_ack = irq_chip_ack_parent,
>
> There is no point calling irq_chip_ack_parent, as the GIC doesn't
> implement an irq_ack method at all.
>

Thanks Marc, let me remove it.

>> + .irq_eoi = irq_chip_eoi_parent,
>> + .irq_mask = irq_chip_mask_parent,
>> + .irq_unmask = irq_chip_unmask_parent,
>> + .irq_set_type = xgene_gpio_sb_irq_set_type,
>> + .irq_shutdown = xgene_gpio_sb_irq_shutdown,
>> +};
>> +
>> +static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
>> {
>> struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
>> + struct irq_fwspec fwspec;
>> +
>> + if ((gpio < priv->irq_start) ||
>> + (gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
>> + return -ENXIO;
>> +
>> + if (gc->parent->of_node)
>> + fwspec.fwnode = of_node_to_fwnode(gc->parent->of_node);
>> + else
>> + fwspec.fwnode = gc->parent->fwnode;
>> + fwspec.param_count = 2;
>> + fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
>> + fwspec.param[1] = IRQ_TYPE_NONE;
>> + return irq_create_fwspec_mapping(&fwspec);
>> +}
>> +
>> +static void xgene_gpio_sb_domain_activate(struct irq_domain *d,
>> + struct irq_data *irq_data)
>> +{
>> + struct xgene_gpio_sb *priv = d->host_data;
>> + u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
>> +
>> + if (gpiochip_lock_as_irq(&priv->gc, gpio)) {
>> + dev_err(priv->gc.parent,
>> + "Unable to configure XGene GPIO standby pin %d as IRQ\n",
>> + gpio);
>> + return;
>> + }
>> +
>> + xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
>> + gpio * 2, 1);
>> +}
>> +
>> +static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
>> + struct irq_data *irq_data)
>> +{
>> + struct xgene_gpio_sb *priv = d->host_data;
>> + u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
>> +
>> + gpiochip_unlock_as_irq(&priv->gc, gpio);
>
> Is it right to do the unlock both in irq_shutdown and domain_deactivate?
> This seems a bit odd to me to have such an inbalance. My hunch is that
> you should either implement irq_startup, do the locking there and drop
> the unlock drop deactivate, or kill irq_shutdown.
>
> Linus, what do you think?
>

I refer to kill irq_shutdown.

>> + xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
>> + gpio * 2, 0);
>> +}
>>
>> - if (priv->irq[gpio])
>> - return priv->irq[gpio];
>> +static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
>> + struct irq_fwspec *fwspec,
>> + unsigned long *hwirq,
>> + unsigned int *type)
>> +{
>> + struct xgene_gpio_sb *priv = d->host_data;
>> +
>> + if ((fwspec->param_count != 2) ||
>> + (fwspec->param[0] >= priv->nirq))
>> + return -EINVAL;
>> + *hwirq = fwspec->param[0];
>> + *type = fwspec->param[1];
>> + return 0;
>> +}
>> +
>> +static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
>> + unsigned int virq,
>> + unsigned int nr_irqs, void *data)
>> +{
>> + struct irq_fwspec *fwspec = data;
>> + struct irq_fwspec parent_fwspec;
>> + struct xgene_gpio_sb *priv = domain->host_data;
>> + irq_hw_number_t hwirq;
>> + unsigned int i;
>> +
>> + hwirq = fwspec->param[0];
>> + for (i = 0; i < nr_irqs; i++)
>> + irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
>> + &xgene_gpio_sb_irq_chip, priv);
>> +
>> + if (is_of_node(domain->parent->fwnode)) {
>> + parent_fwspec.fwnode = domain->parent->fwnode;
>> + parent_fwspec.param_count = 3;
>> + parent_fwspec.param[0] = 0;/* SPI */
>> + /* Skip SGIs and PPIs*/
>> + parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
>> + parent_fwspec.param[2] = fwspec->param[1];
>> + } else if (is_fwnode_irqchip(domain->parent->fwnode)) {
>> + parent_fwspec.fwnode = domain->parent->fwnode;
>
> nit: You can move this out of the if/else, and always assign the fwnode.

Thanks Marc, let me change it.

>
>> + parent_fwspec.param_count = 2;
>> + parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
>> + parent_fwspec.param[1] = fwspec->param[1];
>> + } else
>> + return -EINVAL;
>>
>> - return -ENXIO;
>> + return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
>> + &parent_fwspec);
>> }
>>
>> +static void xgene_gpio_sb_domain_free(struct irq_domain *domain,
>> + unsigned int virq,
>> + unsigned int nr_irqs)
>> +{
>> + struct irq_data *d;
>> + unsigned int i;
>> +
>> + for (i = 0; i < nr_irqs; i++) {
>> + d = irq_domain_get_irq_data(domain, virq + i);
>> + irq_domain_reset_irq_data(d);
>> + }
>> +}
>> +
>> +static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
>> + .translate = xgene_gpio_sb_domain_translate,
>> + .alloc = xgene_gpio_sb_domain_alloc,
>> + .free = xgene_gpio_sb_domain_free,
>> + .activate = xgene_gpio_sb_domain_activate,
>> + .deactivate = xgene_gpio_sb_domain_deactivate,
>> +};
>> +
>> static int xgene_gpio_sb_probe(struct platform_device *pdev)
>> {
>> struct xgene_gpio_sb *priv;
>> - u32 ret, i;
>> - u32 default_lines[] = {0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D};
>> + u32 ret;
>> struct resource *res;
>> void __iomem *regs;
>> + struct irq_domain *parent_domain = NULL;
>> + struct fwnode_handle *fwnode;
>> + u32 val32;
>>
>> priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>> if (!priv)
>> @@ -90,6 +266,18 @@ static int xgene_gpio_sb_probe(struct platform_device *pdev)
>> if (IS_ERR(regs))
>> return PTR_ERR(regs);
>>
>> + priv->regs = regs;
>> +
>> + ret = platform_get_irq(pdev, 0);
>> + if (ret > 0) {
>> + priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
>> + parent_domain = irq_get_irq_data(ret)->domain;
>> + }
>> + if (!parent_domain) {
>> + dev_err(&pdev->dev, "unable to obtain parent domain\n");
>> + return -ENODEV;
>> + }
>> +
>> ret = bgpio_init(&priv->gc, &pdev->dev, 4,
>> regs + MPA_GPIO_IN_ADDR,
>> regs + MPA_GPIO_OUT_ADDR, NULL,
>> @@ -97,30 +285,51 @@ static int xgene_gpio_sb_probe(struct platform_device *pdev)
>> if (ret)
>> return ret;
>>
>> - priv->gc.to_irq = apm_gpio_sb_to_irq;
>> - priv->gc.ngpio = XGENE_MAX_GPIO_DS;
>> + priv->gc.to_irq = xgene_gpio_sb_to_irq;
>>
>> - priv->nirq = XGENE_MAX_GPIO_DS_IRQ;
>> + /* Retrieve start irq pin, use default if property not found */
>> + priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
>> + if (!device_property_read_u32(&pdev->dev,
>> + XGENE_IRQ_START_PROPERTY, &val32))
>
> Is that for ACPI as well?
>

Yes, Marc.

>> + priv->irq_start = val32;
>>
>> - priv->irq = devm_kzalloc(&pdev->dev, sizeof(u32) * XGENE_MAX_GPIO_DS,
>> - GFP_KERNEL);
>> - if (!priv->irq)
>> - return -ENOMEM;
>> + /* Retrieve number irqs, use default if property not found */
>> + priv->nirq = XGENE_DFLT_MAX_NIRQ;
>> + if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
>> + priv->nirq = val32;
>>
>> - for (i = 0; i < priv->nirq; i++) {
>> - priv->irq[default_lines[i]] = platform_get_irq(pdev, i);
>> - xgene_gpio_set_bit(&priv->gc, regs + MPA_GPIO_SEL_LO,
>> - default_lines[i] * 2, 1);
>> - xgene_gpio_set_bit(&priv->gc, regs + MPA_GPIO_INT_LVL, i, 1);
>> - }
>> + /* Retrieve number gpio, use default if property not found */
>> + priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
>> + if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
>> + priv->gc.ngpio = val32;
>> +
>> + dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
>> + priv->gc.ngpio, priv->nirq, priv->irq_start);
>>
>> platform_set_drvdata(pdev, priv);
>>
>> - ret = gpiochip_add_data(&priv->gc, priv);
>> - if (ret)
>> - dev_err(&pdev->dev, "failed to register X-Gene GPIO Standby driver\n");
>> + if (pdev->dev.of_node)
>> + fwnode = of_node_to_fwnode(pdev->dev.of_node);
>> else
>> - dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
>> + fwnode = pdev->dev.fwnode;
>> +
>> + priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
>> + 0, priv->nirq, fwnode,
>> + &xgene_gpio_sb_domain_ops, priv);
>> + if (!priv->irq_domain)
>> + return -ENODEV;
>> +
>> + priv->gc.irqdomain = priv->irq_domain;
>> +
>> + ret = gpiochip_add_data(&priv->gc, priv);
>> + if (ret) {
>> + dev_err(&pdev->dev,
>> + "failed to register X-Gene GPIO Standby driver\n");
>> + irq_domain_remove(priv->irq_domain);
>> + return ret;
>> + }
>> +
>> + dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
>>
>> if (priv->nirq > 0) {
>> /* Register interrupt handlers for gpio signaled acpi events */
>> @@ -138,6 +347,8 @@ static int xgene_gpio_sb_remove(struct platform_device *pdev)
>> acpi_gpiochip_free_interrupts(&priv->gc);
>> }
>>
>> + irq_domain_remove(priv->irq_domain);
>> +
>> gpiochip_remove(&priv->gc);
>> return 0;
>> }
>>
>
> Thanks,
>
> M.
> --
> Jazz is not dead. It just smells funny...
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