On 10/06/17 22:57, Heiner Kallweit wrote:
> Add a driver supporting the GPIO interrupt controller on certain
> Amlogic meson SoC's.
>
> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> ---
> v5:
> - changed Kconfig entry based on Neil's suggestion
> - added authors
> - extended explanation why 2 * n hwirqs are used
> v6:
> - change DT property parent-interrupts to interrupts
> v7:
> - no changes
> ---
> drivers/irqchip/Kconfig | 5 +
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-meson-gpio.c | 295 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 301 insertions(+)
> create mode 100644 drivers/irqchip/irq-meson-gpio.c
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 478f8ace..bdc86e14 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -301,3 +301,8 @@ config QCOM_IRQ_COMBINER
> help
> Say yes here to add support for the IRQ combiner devices embedded
> in Qualcomm Technologies chips.
> +
> +config MESON_GPIO_INTC
> + bool
> + depends on ARCH_MESON
> + default y
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index b64c59b8..1be482bd 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -76,3 +76,4 @@ obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
> obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o
> obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
> obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
> +obj-$(CONFIG_MESON_GPIO_INTC) += irq-meson-gpio.o
> diff --git a/drivers/irqchip/irq-meson-gpio.c b/drivers/irqchip/irq-meson-gpio.c
> new file mode 100644
> index 00000000..925d00c2
> --- /dev/null
> +++ b/drivers/irqchip/irq-meson-gpio.c
> @@ -0,0 +1,295 @@
> +/*
> + * Amlogic Meson GPIO IRQ chip driver
> + *
> + * Copyright (c) 2015 Endless Mobile, Inc.
> + * Author: Carlo Caione <carlo@xxxxxxxxxxxx>
> + * Copyright (c) 2016 BayLibre, SAS.
> + * Author: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> + * Copyright (c) 2017 Heiner Kallweit <hkallweit1@xxxxxxxxx>
> + *
> + * 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/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +#include <linux/regmap.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 MAX_PARENT_IRQ_NUM 8
> +
> +/* maximum number of GPIO IRQs on supported platforms */
> +#define MAX_NUM_GPIO_IRQ 133
Why aren't these values coming from DT? I bet that a future revision of
the same HW will double these. Or at least, you could match it on the
compatible string.
> +
> +/*
> + * In case of IRQ_TYPE_EDGE_BOTH we need two parent interrupts, one for each
> + * edge. That's due to HW constraints.
> + * We use format 2 * GPIO_HWIRQ +(0|1) for the hwirq, so we can have one
> + * GPIO_HWIRQ twice and derive the GPIO_HWIRQ from hwirq by shifting hwirq
> + * one bit to the right.
Please expand on how you expect this to work, specially when a random
driver expects a single interrupt.
> + */
> +#define NUM_GPIO_HWIRQ (2 * MAX_NUM_GPIO_IRQ)
> +
> +struct meson_irq_slot {
> + unsigned int irq;
> + unsigned int owner;
> +};
> +
> +struct meson_data {
> + struct regmap *regmap;
> + struct meson_irq_slot slots[MAX_PARENT_IRQ_NUM];
> + unsigned int num_slots;
> + struct mutex lock;
> +};
> +
> +static int meson_alloc_irq_slot(struct meson_data *md, unsigned int virq)
> +{
> + int i, slot = -ENOSPC;
> +
> + mutex_lock(&md->lock);
> +
> + for (i = 0; i < md->num_slots && slot < 0; i++)
> + if (!md->slots[i].owner) {
> + md->slots[i].owner = virq;
Why do you have to deal with the virq? It'd be more logical to deal with
the hwirq. The usual mechanism to reserve a "slot" is to use a bitmap
indexed by the hwirq. Why is that not working for you?
> + slot = i;
> + }
> +
> + mutex_unlock(&md->lock);
> +
> + return slot;
> +}
> +
> +static void meson_free_irq_slot(struct meson_data *md, unsigned int virq)
> +{
> + int i;
> +
> + mutex_lock(&md->lock);
> +
> + for (i = 0; i < md->num_slots; i++)
> + if (md->slots[i].owner == virq) {
> + md->slots[i].owner = 0;
> + break;
> + }
> +
> + mutex_unlock(&md->lock);
> +}
These two functions are basically the same...
> +
> +static int meson_find_irq_slot(struct meson_data *md, unsigned int virq)
> +{
> + int i, slot = -EINVAL;
> +
> + mutex_lock(&md->lock);
> +
> + for (i = 0; i < md->num_slots && slot < 0; i++)
> + if (md->slots[i].owner == virq)
> + slot = i;
> +
> + mutex_unlock(&md->lock);
> +
> + return slot;
> +}
... and could be expressed in terms of this one.
> +
> +static void meson_set_hwirq(struct meson_data *md, int idx, unsigned int hwirq)
> +{
> + int reg = idx > 3 ? REG_PIN_47_SEL : REG_PIN_03_SEL;
> + int shift = 8 * (idx % 4);
What's this?
> +
> + regmap_update_bits(md->regmap, reg, 0xff << shift,
> + hwirq << shift);
> +}
> +
> +static void meson_irq_set_hwirq(struct irq_data *data, unsigned int hwirq)
> +{
> + struct meson_data *md = data->domain->host_data;
> + int slot = meson_find_irq_slot(md, data->irq);
> +
> + if (slot >= 0)
> + meson_set_hwirq(md, slot, hwirq);
> +}
> +
> +static int meson_irq_set_type(struct irq_data *data, unsigned int type)
> +{
> + struct meson_data *md = data->domain->host_data;
> + int slot;
> + unsigned int val = 0;
> +
> + if (type == IRQ_TYPE_EDGE_BOTH)
> + return -EINVAL;
So you reject EDGE_BOTH? So what's the deal with the beginning of the patch?
> +
> + slot = meson_find_irq_slot(md, data->irq);
> + if (slot < 0)
> + return slot;
How can this happen?
> +
> + if (type & IRQ_TYPE_EDGE_BOTH)
> + val |= REG_EDGE_POL_EDGE(slot);
> +
> + if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING))
> + val |= REG_EDGE_POL_LOW(slot);
> +
> + regmap_update_bits(md->regmap, REG_EDGE_POL,
> + REG_EDGE_POL_MASK(slot), val);
> +
> + if (type & IRQ_TYPE_EDGE_BOTH)
> + val = IRQ_TYPE_EDGE_RISING;
> + else
> + val = IRQ_TYPE_LEVEL_HIGH;
How does this work? Does this HW have some magic falling->rising and
low->high conversion feature? If it doesn't, I cannot see how this can work.
> +
> + return irq_chip_set_type_parent(data, val);
> +}
> +
> +static unsigned int meson_irq_startup(struct irq_data *data)
> +{
> + irq_chip_unmask_parent(data);
> + /*
> + * An extra bit was added to allow having the same gpio hwirq twice
> + * for handling IRQ_TYPE_EDGE_BOTH. Remove this bit to get the
> + * gpio hwirq.
> + */
> + meson_irq_set_hwirq(data, data->hwirq >> 1);
Again. Do you support EDGE_BOTH or not?
> +
> + return 0;
> +}
> +
> +static void meson_irq_shutdown(struct irq_data *data)
> +{
> + meson_irq_set_hwirq(data, 0xff);
What's special about 0xff?
> + irq_chip_mask_parent(data);
> +}
> +
> +static struct irq_chip meson_irq_chip = {
> + .name = "meson_gpio_intc",
> + .irq_set_type = meson_irq_set_type,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_mask = irq_chip_mask_parent,
> + .irq_unmask = irq_chip_unmask_parent,
> + .irq_startup = meson_irq_startup,
> + .irq_shutdown = meson_irq_shutdown,
> + .irq_set_affinity = irq_chip_set_affinity_parent,
> +};
> +
> +static int meson_irq_alloc(struct irq_domain *d, unsigned int virq,
> + unsigned int nr_irqs, void *data)
> +{
> + struct irq_fwspec parent_fwspec, *fwspec = data;
> + struct meson_data *md = d->host_data;
> + irq_hw_number_t hwirq;
> + int ret, slot;
> +
> + slot = meson_alloc_irq_slot(md, virq);
> + if (slot < 0)
> + return slot;
> +
> + hwirq = fwspec->param[0];
> + irq_domain_set_hwirq_and_chip(d, virq, hwirq, &meson_irq_chip, NULL);
> +
> + parent_fwspec.fwnode = d->parent->fwnode;
> + parent_fwspec.param_count = 3;
> + parent_fwspec.param[0] = 0; /* SPI */
> + parent_fwspec.param[1] = md->slots[slot].irq;
> + parent_fwspec.param[2] = IRQ_TYPE_NONE;
Hell no. Look at the GIC DT binding: there is no NONE. It is either
HIGH, or RISING.
> +
> + ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &parent_fwspec);
> + if (ret)
> + meson_free_irq_slot(md, virq);
> +
> + return ret;
> +}
> +
> +static void meson_irq_free(struct irq_domain *d, unsigned int virq,
> + unsigned int nr_irqs)
> +{
> + struct meson_data *md = d->host_data;
> +
> + irq_domain_free_irqs_common(d, virq, nr_irqs);
> + meson_free_irq_slot(md, virq);
> +}
> +
> +static const struct irq_domain_ops meson_irq_ops = {
> + .alloc = meson_irq_alloc,
> + .free = meson_irq_free,
> + .xlate = irq_domain_xlate_twocell,
> +};
> +
> +static int meson_get_irqs(struct meson_data *md, struct device_node *node)
> +{
> + int ret, i;
> + u32 irq;
> +
> + for (i = 0; i < MAX_PARENT_IRQ_NUM; i++) {
> + ret = of_property_read_u32_index(node, "interrupts", i, &irq);
> + if (ret)
> + break;
> + md->slots[i].irq = irq;
> + }
> +
> + md->num_slots = i;
> +
> + return i ? 0 : -EINVAL;
> +}
> +
> +static const struct regmap_config meson_regmap_config = {
> + .reg_bits = 32,
> + .reg_stride = 4,
> + .val_bits = 32,
> + .max_register = REG_FILTER_SEL,
> +};
> +
> +static int __init meson_gpio_irq_init(struct device_node *node,
> + struct device_node *parent)
> +{
> + struct irq_domain *meson_irq_domain, *parent_domain;
> + struct meson_data *md;
> + void __iomem *io_base;
> + int ret;
> +
> + md = kzalloc(sizeof(*md), GFP_KERNEL);
> + if (!md)
> + return -ENOMEM;
> +
> + mutex_init(&md->lock);
> +
> + io_base = of_iomap(node, 0);
> + if (!io_base)
> + return -EINVAL;
> +
> + md->regmap = regmap_init_mmio(NULL, io_base, &meson_regmap_config);
> + if (IS_ERR(md->regmap))
> + return PTR_ERR(md->regmap);
> +
> + /* initialize to IRQ_TYPE_LEVEL_HIGH */
> + regmap_write(md->regmap, REG_EDGE_POL, 0);
> + /* disable all GPIO interrupt sources */
> + regmap_write(md->regmap, REG_PIN_03_SEL, 0xffffffff);
> + regmap_write(md->regmap, REG_PIN_47_SEL, 0xffffffff);
> + /* disable filtering */
> + regmap_write(md->regmap, REG_FILTER_SEL, 0);
> +
> + ret = meson_get_irqs(md, node);
> + if (ret)
> + return ret;
> +
> + parent_domain = irq_find_host(parent);
> + if (!parent_domain)
> + return -ENXIO;
Memory leak on all the return paths.
> +
> + meson_irq_domain = irq_domain_add_hierarchy(parent_domain, 0,
> + NUM_GPIO_HWIRQ, node,
> + &meson_irq_ops, md);
> + return meson_irq_domain ? 0 : -EINVAL;
> +}
> +
> +IRQCHIP_DECLARE(meson_gpio_irq, "amlogic,meson-gpio-intc", meson_gpio_irq_init);
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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