[PATCH v3 2/4] gpio: visconti: Add Toshiba Visconti GPIO support
Punit Agrawal
punit1.agrawal at toshiba.co.jp
Thu Dec 3 05:03:27 EST 2020
Hi Iwamatsu-san,
A couple of very minor comments below -
Nobuhiro Iwamatsu <nobuhiro1.iwamatsu at toshiba.co.jp> writes:
> Add the GPIO driver for Toshiba Visconti ARM SoCs.
>
> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu at toshiba.co.jp>
> ---
> drivers/gpio/Kconfig | 9 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-visconti.c | 232 ++++++++++++++++++++++
> drivers/pinctrl/visconti/pinctrl-common.c | 23 +++
> 4 files changed, 265 insertions(+)
> create mode 100644 drivers/gpio/gpio-visconti.c
>
[...]
> diff --git a/drivers/gpio/gpio-visconti.c b/drivers/gpio/gpio-visconti.c
> new file mode 100644
> index 000000000000..17e6da161f48
> --- /dev/null
> +++ b/drivers/gpio/gpio-visconti.c
> @@ -0,0 +1,232 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Toshiba Visconti GPIO Support
> + *
> + * (C) Copyright 2020 Toshiba Electronic Devices & Storage Corporation
> + * (C) Copyright 2020 Nobuhiro Iwamatsu <nobuhiro1.iwamatsu at toshiba.co.jp>
> + */
> +
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/of.h>
> +#include <linux/bitops.h>
> +
> +/* register offset */
> +#define GPIO_DIR 0x00
> +#define GPIO_IDATA 0x08
> +#define GPIO_ODATA 0x10
> +#define GPIO_OSET 0x18
> +#define GPIO_OCLR 0x20
> +#define GPIO_INTMODE 0x30
> +
> +#define VISCONTI_GPIO_NR 32
The macro doesn't seem to be used. Can we drop this? On the other hand
should there be a macro to indicate the maximum number of GPIO lines
that support interrupt (16)?
> +
> +struct visconti_gpio {
> + void __iomem *base;
> + int *irq;
> + spinlock_t lock; /* protect gpio register */
> + struct device *dev;
> + struct gpio_chip gpio_chip;
> + struct irq_chip irq_chip;
> +};
> +
> +static void visconti_gpio_irq_mask(struct irq_data *d)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> + struct visconti_gpio *priv = gpiochip_get_data(gc);
> +
> + disable_irq_nosync(priv->irq[irqd_to_hwirq(d)]);
> +}
> +
> +static void visconti_gpio_irq_unmask(struct irq_data *d)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> + struct visconti_gpio *priv = gpiochip_get_data(gc);
> +
> + enable_irq(priv->irq[irqd_to_hwirq(d)]);
> +}
> +
> +static int visconti_gpio_irq_set_type(struct irq_data *d, unsigned int type)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> + struct visconti_gpio *priv = gpiochip_get_data(gc);
> + u32 offset = irqd_to_hwirq(d);
> + u32 bit = BIT(offset);
> + u32 intc_type = IRQ_TYPE_EDGE_RISING;
> + u32 intmode, odata;
> + int ret = 0;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&priv->lock, flags);
> +
> + odata = readl(priv->base + GPIO_ODATA);
> + intmode = readl(priv->base + GPIO_INTMODE);
> +
> + switch (type) {
> + case IRQ_TYPE_EDGE_RISING:
> + odata &= ~bit;
> + intmode &= ~bit;
> + break;
> + case IRQ_TYPE_EDGE_FALLING:
> + odata |= bit;
> + intmode &= ~bit;
> + break;
> + case IRQ_TYPE_EDGE_BOTH:
> + intmode |= bit;
> + break;
> + case IRQ_TYPE_LEVEL_HIGH:
> + intc_type = IRQ_TYPE_LEVEL_HIGH;
> + odata &= ~bit;
> + intmode &= ~bit;
> + break;
> + case IRQ_TYPE_LEVEL_LOW:
> + intc_type = IRQ_TYPE_LEVEL_HIGH;
> + odata |= bit;
> + intmode &= ~bit;
> + break;
> + default:
> + ret = -EINVAL;
> + goto err;
> + }
> +
> + writel(odata, priv->base + GPIO_ODATA);
> + writel(intmode, priv->base + GPIO_INTMODE);
> + irq_set_irq_type(priv->irq[offset], intc_type);
> +err:
> + spin_unlock_irqrestore(&priv->lock, flags);
> +
> + return ret;
> +}
> +
> +static irqreturn_t visconti_gpio_irq_handler(int irq, void *dev_id)
> +{
> + struct visconti_gpio *priv = dev_id;
> + u32 offset = irq - priv->irq[0];
> +
> + generic_handle_irq(irq_find_mapping(priv->gpio_chip.irq.domain, offset));
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void visconti_init_irq_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
> + unsigned int ngpios)
> +{
> + int i;
> +
> + /* Exclude GPIO pins 16-31 from irq */
> + for (i = 16; i < ngpios; i++)
> + clear_bit(i, valid_mask);
> +}
> +
> +static int visconti_gpio_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct visconti_gpio *priv;
> + struct irq_chip *irq_chip;
> + struct irq_desc *desc;
> + struct gpio_irq_chip *girq;
> + const char *name = dev_name(dev);
> + int i, ret, num_irq;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->dev = dev;
> + spin_lock_init(&priv->lock);
> +
> + priv->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(priv->base))
> + return PTR_ERR(priv->base);
> +
> + ret = platform_irq_count(pdev);
> + if (!ret) {
> + dev_err(dev, "Couldn't determine # GPIO banks\n");
> + return -ENOENT;
> + }
platform_irq_count() can return -EPROBE_DEFER. Is that something that
should be handled?
With the above two comments addressed, feel free to add
Reviewed-by: Punit Agrawal <punit1.agrawal at toshiba.co.jp>
Thanks,
Punit
> + num_irq = ret;
> +
> + priv->irq = devm_kcalloc(dev, num_irq, sizeof(priv->irq), GFP_KERNEL);
> + if (!priv->irq)
> + return -ENOMEM;
> +
> + for (i = 0; i < num_irq; i++) {
> + priv->irq[i] = platform_get_irq(pdev, i);
> + if (priv->irq[i] < 0) {
> + dev_err(dev, "invalid IRQ[%d]\n", i);
> + return priv->irq[i];
> + }
> + }
> +
> + ret = bgpio_init(&priv->gpio_chip, dev, 4,
> + priv->base + GPIO_IDATA,
> + priv->base + GPIO_OSET,
> + priv->base + GPIO_OCLR,
> + priv->base + GPIO_DIR,
> + NULL,
> + 0);
> + if (ret) {
> + dev_err(dev, "unable to init generic GPIO\n");
> + return ret;
> + }
> +
> + priv->gpio_chip.irq.init_valid_mask = visconti_init_irq_valid_mask;
> +
> + irq_chip = &priv->irq_chip;
> + irq_chip->name = "gpio-visconti";
> + irq_chip->irq_mask = visconti_gpio_irq_mask;
> + irq_chip->irq_unmask = visconti_gpio_irq_unmask;
> + irq_chip->irq_set_type = visconti_gpio_irq_set_type;
> + irq_chip->flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
> +
> + girq = &priv->gpio_chip.irq;
> + girq->chip = irq_chip;
> + /* This will let us handle the parent IRQ in the driver */
> + girq->parent_handler = NULL;
> + girq->num_parents = 0;
> + girq->parents = NULL;
> + girq->default_type = IRQ_TYPE_NONE;
> + girq->handler = handle_level_irq;
> +
> + ret = devm_gpiochip_add_data(dev, &priv->gpio_chip, priv);
> + if (ret) {
> + dev_err(dev, "failed to add GPIO chip\n");
> + return ret;
> + }
> +
> + for (i = 0; i < num_irq; i++) {
> + desc = irq_to_desc(priv->irq[i]);
> + desc->status_use_accessors |= IRQ_NOAUTOEN;
> + if (devm_request_irq(dev, priv->irq[i],
> + visconti_gpio_irq_handler, 0, name, priv)) {
> + dev_err(dev, "failed to request IRQ[%d]\n", i);
> + return -ENOENT;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static const struct of_device_id visconti_gpio_of_match[] = {
> + { .compatible = "toshiba,gpio-tmpv7708", },
> + { /* end of table */ }
> +};
> +MODULE_DEVICE_TABLE(of, visconti_gpio_of_match);
> +
> +static struct platform_driver visconti_gpio_driver = {
> + .probe = visconti_gpio_probe,
> + .driver = {
> + .name = "visconti_gpio",
> + .of_match_table = of_match_ptr(visconti_gpio_of_match),
> + }
> +};
> +module_platform_driver(visconti_gpio_driver);
> +
> +MODULE_AUTHOR("Toshiba Electronic Devices & Storage Corporation");
> +MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu at toshiba.co.jp>");
> +MODULE_DESCRIPTION("Toshiba Visconti GPIO Driver");
> +MODULE_LICENSE("GPL v2");
[...]
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