[PATCH v2 6/6] pintrl: meson: add support for GPIO interrupts
Heiner Kallweit
hkallweit1 at gmail.com
Fri May 12 12:14:26 PDT 2017
Add support for GPIO interrupts on Amlogic Meson SoC's.
There's a limit of 8 parent interupts which can be used in total.
Note that IRQ_TYPE_EDGE_BOTH interrupts reserve two parent IRQ's,
one for each edge.
Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
---
v2:
- make the GPIO IRQ controller a separate driver
- several smaller improvements
---
drivers/pinctrl/Kconfig | 1 +
drivers/pinctrl/meson/Makefile | 2 +-
drivers/pinctrl/meson/pinctrl-meson-irq.c | 367 ++++++++++++++++++++++++++++++
drivers/pinctrl/meson/pinctrl-meson.c | 8 +-
drivers/pinctrl/meson/pinctrl-meson.h | 1 +
5 files changed, 377 insertions(+), 2 deletions(-)
create mode 100644 drivers/pinctrl/meson/pinctrl-meson-irq.c
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 37af5e30..f8f401a0 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -153,6 +153,7 @@ config PINCTRL_MESON
select PINCONF
select GENERIC_PINCONF
select GPIOLIB
+ select GPIOLIB_IRQCHIP
select OF_GPIO
select REGMAP_MMIO
diff --git a/drivers/pinctrl/meson/Makefile b/drivers/pinctrl/meson/Makefile
index 27c5b512..827e416d 100644
--- a/drivers/pinctrl/meson/Makefile
+++ b/drivers/pinctrl/meson/Makefile
@@ -1,3 +1,3 @@
obj-y += pinctrl-meson8.o pinctrl-meson8b.o
obj-y += pinctrl-meson-gxbb.o pinctrl-meson-gxl.o
-obj-y += pinctrl-meson.o
+obj-y += pinctrl-meson.o pinctrl-meson-irq.o
diff --git a/drivers/pinctrl/meson/pinctrl-meson-irq.c b/drivers/pinctrl/meson/pinctrl-meson-irq.c
new file mode 100644
index 00000000..c5f403f3
--- /dev/null
+++ b/drivers/pinctrl/meson/pinctrl-meson-irq.c
@@ -0,0 +1,367 @@
+/*
+ * Amlogic Meson GPIO IRQ driver
+ *
+ * Copyright 2017 Heiner Kallweit <hkallweit1 at gmail.com>
+ * Based on a first version by Jerome Brunet <jbrunet at baylibre.com>
+ *
+ * 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 Free Software Foundation, version 2.
+ */
+
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include "pinctrl-meson.h"
+
+#define REG_EDGE_POL 0x00
+#define REG_PIN_03_SEL 0x04
+#define REG_PIN_47_SEL 0x08
+#define REG_FILTER_SEL 0x0c
+
+#define REG_EDGE_POL_MASK(x) (BIT(x) | BIT(16 + (x)))
+#define REG_EDGE_POL_EDGE(x) BIT(x)
+#define REG_EDGE_POL_LOW(x) BIT(16 + (x))
+
+#define MESON_GPIO_MAX_PARENT_IRQ_NUM 8
+
+struct meson_gpio_irq_slot {
+ int irq;
+ int owner;
+};
+
+static struct regmap *meson_gpio_irq_regmap;
+static struct meson_gpio_irq_slot
+ meson_gpio_irq_slots[MESON_GPIO_MAX_PARENT_IRQ_NUM];
+static int meson_gpio_num_irq_slots;
+static DEFINE_MUTEX(meson_gpio_irq_slot_mutex);
+static DECLARE_BITMAP(meson_gpio_irq_locked, 256);
+
+static struct meson_pinctrl *meson_gpio_data_to_pc(struct irq_data *data)
+{
+ struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+
+ return gpiochip_get_data(chip);
+}
+
+static int meson_gpio_to_hwirq(struct meson_bank *bank, unsigned int offset)
+{
+ int hwirq;
+
+ if (bank->irq_first < 0)
+ /* this bank cannot generate irqs */
+ return 0;
+
+ hwirq = offset - bank->first + bank->irq_first;
+
+ if (hwirq > bank->irq_last)
+ /* this pin cannot generate irqs */
+ return 0;
+
+ return hwirq;
+}
+
+static int meson_gpio_to_irq(struct meson_pinctrl *pc, unsigned int offset)
+{
+ struct meson_bank *bank;
+ int hwirq;
+
+ offset += pc->data->pin_base;
+
+ bank = meson_pinctrl_get_bank(pc, offset);
+ if (IS_ERR(bank))
+ return PTR_ERR(bank);
+
+ hwirq = meson_gpio_to_hwirq(bank, offset);
+ if (!hwirq)
+ dev_dbg(pc->dev, "no interrupt for pin %u\n", offset);
+
+ return hwirq;
+}
+
+static int meson_gpio_data_to_hwirq(struct irq_data *data)
+{
+ struct meson_pinctrl *pc = meson_gpio_data_to_pc(data);
+ unsigned gpio = irqd_to_hwirq(data);
+
+ return meson_gpio_to_irq(pc, gpio);
+}
+
+static irqreturn_t meson_gpio_irq_handler(int irq, void *data)
+{
+ struct irq_data *gpio_irqdata = data;
+ struct meson_pinctrl *pc = meson_gpio_data_to_pc(data);
+ int hwirq = meson_gpio_data_to_hwirq(gpio_irqdata);
+
+ /*
+ * For some strange reason spurious interrupts created by the chip when
+ * the interrupt source registers are written cause a deadlock here.
+ * generic_handle_irq calls handle_simple_irq which tries to get
+ * spinlock desc->lock. This interrupt handler is called whilst
+ * __setup_irq holds desc->lock.
+ * The deadlock means that both are running on the same CPU what should
+ * not happen as __setup_irq called raw_spin_lock_irqsave thus disabling
+ * interrupts on this CPU.
+ * Work around this by ignoring interrupts in code protected by
+ * chip_bus_lock (__setup_irq/__free_irq for the respective GPIO hwirq).
+ */
+ if (test_bit(hwirq, meson_gpio_irq_locked))
+ dev_dbg(pc->dev, "spurious interrupt detected!\n");
+ else
+ generic_handle_irq(gpio_irqdata->irq);
+
+ return IRQ_HANDLED;
+}
+
+static int meson_gpio_alloc_irq_slot(struct irq_data *data, int num_slots,
+ int *slots)
+{
+ int i, cnt = 0;
+
+ mutex_lock(&meson_gpio_irq_slot_mutex);
+
+ for (i = 0; i < meson_gpio_num_irq_slots; i++)
+ if (!meson_gpio_irq_slots[i].owner) {
+ meson_gpio_irq_slots[i].owner = data->irq;
+ slots[cnt++] = i;
+ if (cnt == num_slots)
+ break;
+ }
+
+ if (cnt < num_slots)
+ for (i = 0; i < cnt; i++)
+ meson_gpio_irq_slots[i].owner = 0;
+
+ mutex_unlock(&meson_gpio_irq_slot_mutex);
+
+ return cnt == num_slots ? 0 : -ENOSPC;
+}
+
+static void meson_gpio_free_irq_slot(struct irq_data *data)
+{
+ int i;
+
+ mutex_lock(&meson_gpio_irq_slot_mutex);
+
+ for (i = 0; i < meson_gpio_num_irq_slots; i++)
+ if (meson_gpio_irq_slots[i].owner == data->irq) {
+ free_irq(meson_gpio_irq_slots[i].irq, data);
+ meson_gpio_irq_slots[i].owner = 0;
+ }
+
+ mutex_unlock(&meson_gpio_irq_slot_mutex);
+}
+
+static int meson_gpio_find_irq_slot(struct irq_data *data, int *slots)
+{
+ int i, cnt = 0;
+
+ mutex_lock(&meson_gpio_irq_slot_mutex);
+
+ for (i = 0; i < meson_gpio_num_irq_slots; i++)
+ if (meson_gpio_irq_slots[i].owner == data->irq)
+ slots[cnt++] = i;
+
+ mutex_unlock(&meson_gpio_irq_slot_mutex);
+
+ return cnt ?: -EINVAL;
+}
+
+static void meson_gpio_set_hwirq(int idx, int hwirq)
+{
+ int reg = idx > 3 ? REG_PIN_47_SEL : REG_PIN_03_SEL;
+ int shift = 8 * (idx % 4);
+
+ regmap_update_bits(meson_gpio_irq_regmap, reg, 0xff << shift,
+ hwirq << shift);
+}
+
+static void meson_gpio_irq_set_hwirq(struct irq_data *data, int hwirq)
+{
+ struct meson_pinctrl *pc = meson_gpio_data_to_pc(data);
+ int i, cnt, slots[MESON_GPIO_MAX_PARENT_IRQ_NUM];
+
+ cnt = meson_gpio_find_irq_slot(data, slots);
+ if (cnt < 0) {
+ dev_err(pc->dev, "didn't find gpio irq slot\n");
+ return;
+ }
+
+ for (i = 0; i < cnt; i++)
+ meson_gpio_set_hwirq(slots[i], hwirq);
+}
+
+static void meson_gpio_irq_unmask(struct irq_data *data)
+{
+ struct meson_pinctrl *pc = meson_gpio_data_to_pc(data);
+ unsigned gpio = irqd_to_hwirq(data);
+ int hwirq = meson_gpio_to_irq(pc, gpio);
+
+ meson_gpio_irq_set_hwirq(data, hwirq);
+}
+
+static void meson_gpio_irq_mask(struct irq_data *data)
+{
+ meson_gpio_irq_set_hwirq(data, 0xff);
+}
+
+static void meson_gpio_irq_shutdown(struct irq_data *data)
+{
+ meson_gpio_irq_mask(data);
+ meson_gpio_free_irq_slot(data);
+}
+
+static int meson_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ int i, ret, irq, num_slots, slots[MESON_GPIO_MAX_PARENT_IRQ_NUM];
+ unsigned int val = 0;
+
+ num_slots = (type == IRQ_TYPE_EDGE_BOTH) ? 2 : 1;
+ ret = meson_gpio_alloc_irq_slot(data, num_slots, slots);
+ if (ret)
+ return ret;
+
+ if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
+ val |= REG_EDGE_POL_EDGE(slots[0]);
+
+ if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING))
+ val |= REG_EDGE_POL_LOW(slots[0]);
+
+ regmap_update_bits(meson_gpio_irq_regmap, REG_EDGE_POL,
+ REG_EDGE_POL_MASK(slots[0]), val);
+
+ /*
+ * The chip can create an interrupt for either rising or falling edge
+ * only. Therefore use two interrupts in case of IRQ_TYPE_EDGE_BOTH,
+ * first for falling edge and second one for rising edge.
+ */
+ if (num_slots > 1) {
+ val = REG_EDGE_POL_EDGE(slots[1]);
+ regmap_update_bits(meson_gpio_irq_regmap, REG_EDGE_POL,
+ REG_EDGE_POL_MASK(slots[1]), val);
+ }
+
+ if (type & IRQ_TYPE_EDGE_BOTH)
+ val = IRQ_TYPE_EDGE_RISING;
+ else
+ val = IRQ_TYPE_LEVEL_HIGH;
+
+ for (i = 0; i < num_slots; i++) {
+ irq = meson_gpio_irq_slots[slots[i]].irq;
+ ret = irq_set_irq_type(irq, val);
+ if (ret)
+ break;
+ ret = request_irq(irq, meson_gpio_irq_handler, 0,
+ "GPIO parent", data);
+ if (ret)
+ break;
+ }
+
+ if (ret)
+ while (--i >= 0)
+ free_irq(meson_gpio_irq_slots[slots[i]].irq, data);
+
+ return ret;
+}
+
+static void meson_gpio_irq_bus_lock(struct irq_data *data)
+{
+ int hwirq = meson_gpio_data_to_hwirq(data);
+
+ set_bit(hwirq, meson_gpio_irq_locked);
+}
+
+static void meson_gpio_irq_bus_sync_unlock(struct irq_data *data)
+{
+ int hwirq = meson_gpio_data_to_hwirq(data);
+
+ clear_bit(hwirq, meson_gpio_irq_locked);
+}
+
+static struct irq_chip meson_gpio_irq_chip = {
+ .name = "GPIO",
+ .irq_set_type = meson_gpio_irq_set_type,
+ .irq_mask = meson_gpio_irq_mask,
+ .irq_unmask = meson_gpio_irq_unmask,
+ .irq_shutdown = meson_gpio_irq_shutdown,
+ .irq_bus_lock = meson_gpio_irq_bus_lock,
+ .irq_bus_sync_unlock = meson_gpio_irq_bus_sync_unlock,
+};
+
+static int meson_gpio_get_irqs(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ int irq, i;
+
+ for (i = 0; i < MESON_GPIO_MAX_PARENT_IRQ_NUM; i++) {
+ irq = irq_of_parse_and_map(np, i);
+ if (!irq)
+ break;
+ meson_gpio_irq_slots[i].irq = irq;
+ }
+
+ meson_gpio_num_irq_slots = i;
+
+ return i ? 0 : -EINVAL;
+}
+
+static const struct regmap_config meson_gpio_regmap_config = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = REG_FILTER_SEL,
+};
+
+static int meson_gpio_irq_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ void __iomem *io_base;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ io_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(io_base))
+ return PTR_ERR(io_base);
+
+ meson_gpio_irq_regmap = devm_regmap_init_mmio(&pdev->dev, io_base,
+ &meson_gpio_regmap_config);
+ if (IS_ERR(meson_gpio_irq_regmap))
+ return PTR_ERR(meson_gpio_irq_regmap);
+
+ /* initialize to IRQ_TYPE_LEVEL_HIGH */
+ regmap_write(meson_gpio_irq_regmap, REG_EDGE_POL, 0);
+ /* disable all GPIO interrupt sources */
+ regmap_write(meson_gpio_irq_regmap, REG_PIN_03_SEL, 0xffffffff);
+ regmap_write(meson_gpio_irq_regmap, REG_PIN_47_SEL, 0xffffffff);
+ /* disable filtering */
+ regmap_write(meson_gpio_irq_regmap, REG_FILTER_SEL, 0);
+
+ ret = meson_gpio_get_irqs(pdev);
+ if (ret)
+ return ret;
+
+ meson_pinctrl_irq_chip = &meson_gpio_irq_chip;
+
+ return 0;
+}
+
+static const struct of_device_id meson_gpio_irq_dt_match[] = {
+ { .compatible = "amlogic,meson-gpio-interrupt" },
+ { },
+};
+
+static struct platform_driver meson_gpio_irq_driver = {
+ .probe = meson_gpio_irq_probe,
+ .driver = {
+ .name = "meson-gpio-interrupt",
+ .of_match_table = meson_gpio_irq_dt_match,
+ },
+};
+builtin_platform_driver(meson_gpio_irq_driver);
diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
index 39ad9861..c587f6f0 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.c
+++ b/drivers/pinctrl/meson/pinctrl-meson.c
@@ -62,6 +62,8 @@
#include "../pinctrl-utils.h"
#include "pinctrl-meson.h"
+struct irq_chip *meson_pinctrl_irq_chip;
+
/**
* meson_pinctrl_get_bank() - find the bank containing a given pin
*
@@ -551,7 +553,8 @@ static int meson_gpiolib_register(struct meson_pinctrl *pc)
return ret;
}
- return 0;
+ return gpiochip_irqchip_add(&pc->chip, meson_pinctrl_irq_chip, 0,
+ handle_simple_irq, IRQ_TYPE_NONE);
}
static struct regmap_config meson_regmap_config = {
@@ -640,6 +643,9 @@ static int meson_pinctrl_probe(struct platform_device *pdev)
struct meson_pinctrl *pc;
int ret;
+ if (!meson_pinctrl_irq_chip)
+ return -EPROBE_DEFER;
+
pc = devm_kzalloc(dev, sizeof(struct meson_pinctrl), GFP_KERNEL);
if (!pc)
return -ENOMEM;
diff --git a/drivers/pinctrl/meson/pinctrl-meson.h b/drivers/pinctrl/meson/pinctrl-meson.h
index 40b56aff..16aab328 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.h
+++ b/drivers/pinctrl/meson/pinctrl-meson.h
@@ -176,6 +176,7 @@ extern struct meson_pinctrl_data meson_gxbb_periphs_pinctrl_data;
extern struct meson_pinctrl_data meson_gxbb_aobus_pinctrl_data;
extern struct meson_pinctrl_data meson_gxl_periphs_pinctrl_data;
extern struct meson_pinctrl_data meson_gxl_aobus_pinctrl_data;
+extern struct irq_chip *meson_pinctrl_irq_chip;
struct meson_bank *meson_pinctrl_get_bank(const struct meson_pinctrl *pc,
unsigned int pin);
--
2.12.2
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