lkml.org 
[lkml]   [2021]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] gpio: pl061: Support implementations without GPIOINTR line
Date
From: Alexander Sverdlin <alexander.sverdlin@nokia.com>

There are several implementations of PL061 which lack GPIOINTR signal in
hardware and only have individual GPIOMIS[7:0] interrupts. Use the
hierarchical interrupt support of the gpiolib in these cases (if at least 8
IRQs are configured for the PL061).

One in-tree example is arch/arm/boot/dts/axm55xx.dtsi, PL061 instances have
8 IRQs defined, but current driver supports only the first one, so only one
pin would work as IRQ trigger.

Link: https://lore.kernel.org/linux-gpio/CACRpkdZpYzpMDWqJobSYH=JHgB74HbCQihOtexs+sVyo6SRJdA@mail.gmail.com/
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
---
Changelog:
v2: Add pl061_populate_parent_fwspec()

drivers/gpio/Kconfig | 1 +
drivers/gpio/gpio-pl061.c | 91 +++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 85 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e3607ec..456c0a5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -469,6 +469,7 @@ config GPIO_PL061
depends on ARM_AMBA
select IRQ_DOMAIN
select GPIOLIB_IRQCHIP
+ select IRQ_DOMAIN_HIERARCHY
help
Say yes here to support the PrimeCell PL061 GPIO device

diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
index f1b53dd..e95714a 100644
--- a/drivers/gpio/gpio-pl061.c
+++ b/drivers/gpio/gpio-pl061.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm.h>
+#include <linux/of_irq.h>

#define GPIODIR 0x400
#define GPIOIS 0x404
@@ -283,6 +284,64 @@ static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
return irq_set_irq_wake(pl061->parent_irq, state);
}

+static int pl061_child_to_parent_hwirq(struct gpio_chip *gc, unsigned int child,
+ unsigned int child_type,
+ unsigned int *parent,
+ unsigned int *parent_type)
+{
+ struct amba_device *adev = to_amba_device(gc->parent);
+ unsigned int irq = adev->irq[child];
+ struct irq_data *d = irq_get_irq_data(irq);
+
+ if (!d)
+ return -EINVAL;
+
+ *parent_type = irqd_get_trigger_type(d);
+ *parent = irqd_to_hwirq(d);
+ return 0;
+}
+
+#ifdef CONFIG_OF
+void pl061_populate_parent_fwspec(struct gpio_chip *gc,
+ struct irq_fwspec *fwspec,
+ unsigned int parent_hwirq,
+ unsigned int parent_type)
+{
+ struct device_node *dn = to_of_node(gc->irq.fwnode);
+ struct of_phandle_args pha;
+ int i;
+
+ fwspec->param_count = 0;
+
+ if (WARN_ON(!dn))
+ return;
+
+ /*
+ * This brute-force here is because of the fact PL061 is often paired
+ * with GIC-v3, which has 3-cell IRQ specifier (SPI/PPI selection), and
+ * unexpected range shifts in hwirq mapping (SPI IRQs are shifted by
+ * 32). So this is about reversing of gic_irq_domain_translate().
+ */
+ for (i = 0; i < PL061_GPIO_NR; i++) {
+ unsigned int p, pt;
+
+ if (pl061_child_to_parent_hwirq(gc, i, parent_type, &p, &pt))
+ continue;
+ if (p == parent_hwirq)
+ break;
+ }
+ if (WARN_ON(i == PL061_GPIO_NR))
+ return;
+
+ if (WARN_ON(of_irq_parse_one(dn, i, &pha)))
+ return;
+
+ fwspec->param_count = pha.args_count;
+ for (i = 0; i < pha.args_count; i++)
+ fwspec->param[i] = pha.args[i];
+}
+#endif
+
static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device *dev = &adev->dev;
@@ -330,16 +389,34 @@ static int pl061_probe(struct amba_device *adev, const struct amba_id *id)

girq = &pl061->gc.irq;
girq->chip = &pl061->irq_chip;
- girq->parent_handler = pl061_irq_handler;
- girq->num_parents = 1;
- girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
- GFP_KERNEL);
- if (!girq->parents)
- return -ENOMEM;
- girq->parents[0] = irq;
girq->default_type = IRQ_TYPE_NONE;
girq->handler = handle_bad_irq;

+ /*
+ * There are some PL061 implementations which lack GPIOINTR in hardware
+ * and only have individual GPIOMIS[7:0] signals. We distinguish them by
+ * the number of IRQs assigned to the AMBA device.
+ */
+ if (!adev->irq[PL061_GPIO_NR - 1]) {
+ WARN_ON(adev->irq[1]);
+
+ girq->parent_handler = pl061_irq_handler;
+ girq->num_parents = 1;
+ girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
+ GFP_KERNEL);
+ if (!girq->parents)
+ return -ENOMEM;
+ girq->parents[0] = irq;
+ } else {
+ girq->fwnode = dev->fwnode;
+ girq->parent_domain =
+ irq_get_irq_data(adev->irq[PL061_GPIO_NR - 1])->domain;
+ girq->child_to_parent_hwirq = pl061_child_to_parent_hwirq;
+#ifdef CONFIG_OF
+ girq->populate_parent_fwspec = pl061_populate_parent_fwspec;
+#endif
+ }
+
ret = devm_gpiochip_add_data(dev, &pl061->gc, pl061);
if (ret)
return ret;
--
2.10.2
\
 
 \ /
  Last update: 2021-03-18 20:13    [W:0.050 / U:0.544 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site