linux/drivers/gpio/gpio-sta2x11.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* STMicroelectronics ConneXt (STA2X11) GPIO driver
*
* Copyright 2012 ST Microelectronics (Alessandro Rubini)
* Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd.
* Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/gpio/driver.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/mfd/sta2x11-mfd.h>
struct gsta_regs {
u32 dat; /* 0x00 */
u32 dats;
u32 datc;
u32 pdis;
u32 dir; /* 0x10 */
u32 dirs;
u32 dirc;
u32 unused_1c;
u32 afsela; /* 0x20 */
u32 unused_24[7];
u32 rimsc; /* 0x40 */
u32 fimsc;
u32 is;
u32 ic;
};
struct gsta_gpio {
spinlock_t lock;
struct device *dev;
void __iomem *reg_base;
struct gsta_regs __iomem *regs[GSTA_NR_BLOCKS];
struct gpio_chip gpio;
int irq_base;
/* FIXME: save the whole config here (AF, ...) */
unsigned irq_type[GSTA_NR_GPIO];
};
/*
* gpio methods
*/
static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
{
struct gsta_gpio *chip = gpiochip_get_data(gpio);
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
if (val)
writel(bit, &regs->dats);
else
writel(bit, &regs->datc);
}
static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr)
{
struct gsta_gpio *chip = gpiochip_get_data(gpio);
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
return !!(readl(&regs->dat) & bit);
}
static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
int val)
{
struct gsta_gpio *chip = gpiochip_get_data(gpio);
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
writel(bit, &regs->dirs);
/* Data register after direction, otherwise pullup/down is selected */
if (val)
writel(bit, &regs->dats);
else
writel(bit, &regs->datc);
return 0;
}
static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
{
struct gsta_gpio *chip = gpiochip_get_data(gpio);
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
writel(bit, &regs->dirc);
return 0;
}
static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
{
struct gsta_gpio *chip = gpiochip_get_data(gpio);
return chip->irq_base + offset;
}
static void gsta_gpio_setup(struct gsta_gpio *chip) /* called from probe */
{
struct gpio_chip *gpio = &chip->gpio;
/*
* ARCH_NR_GPIOS is currently 256 and dynamic allocation starts
* from the end. However, for compatibility, we need the first
* ConneXt device to start from gpio 0: it's the main chipset
* on most boards so documents and drivers assume gpio0..gpio127
*/
static int gpio_base;
gpio->label = dev_name(chip->dev);
gpio->owner = THIS_MODULE;
gpio->direction_input = gsta_gpio_direction_input;
gpio->get = gsta_gpio_get;
gpio->direction_output = gsta_gpio_direction_output;
gpio->set = gsta_gpio_set;
gpio->dbg_show = NULL;
gpio->base = gpio_base;
gpio->ngpio = GSTA_NR_GPIO;
gpio->can_sleep = false;
gpio->to_irq = gsta_gpio_to_irq;
/*
* After the first device, turn to dynamic gpio numbers.
* For example, with ARCH_NR_GPIOS = 256 we can fit two cards
*/
if (!gpio_base)
gpio_base = -1;
}
/*
* Special method: alternate functions and pullup/pulldown. This is only
* invoked on startup to configure gpio's according to platform data.
* FIXME : this functionality shall be managed (and exported to other drivers)
* via the pin control subsystem.
*/
static void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg)
{
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
unsigned long flags;
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
u32 val;
int err = 0;
pr_info("%s: %p %i %i\n", __func__, chip, nr, cfg);
if (cfg == PINMUX_TYPE_NONE)
return;
/* Alternate function or not? */
spin_lock_irqsave(&chip->lock, flags);
val = readl(&regs->afsela);
if (cfg == PINMUX_TYPE_FUNCTION)
val |= bit;
else
val &= ~bit;
writel(val | bit, &regs->afsela);
if (cfg == PINMUX_TYPE_FUNCTION) {
spin_unlock_irqrestore(&chip->lock, flags);
return;
}
/* not alternate function: set details */
switch (cfg) {
case PINMUX_TYPE_OUTPUT_LOW:
writel(bit, &regs->dirs);
writel(bit, &regs->datc);
break;
case PINMUX_TYPE_OUTPUT_HIGH:
writel(bit, &regs->dirs);
writel(bit, &regs->dats);
break;
case PINMUX_TYPE_INPUT:
writel(bit, &regs->dirc);
val = readl(&regs->pdis) | bit;
writel(val, &regs->pdis);
break;
case PINMUX_TYPE_INPUT_PULLUP:
writel(bit, &regs->dirc);
val = readl(&regs->pdis) & ~bit;
writel(val, &regs->pdis);
writel(bit, &regs->dats);
break;
case PINMUX_TYPE_INPUT_PULLDOWN:
writel(bit, &regs->dirc);
val = readl(&regs->pdis) & ~bit;
writel(val, &regs->pdis);
writel(bit, &regs->datc);
break;
default:
err = 1;
}
spin_unlock_irqrestore(&chip->lock, flags);
if (err)
pr_err("%s: chip %p, pin %i, cfg %i is invalid\n",
__func__, chip, nr, cfg);
}
/*
* Irq methods
*/
static void gsta_irq_disable(struct irq_data *data)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
struct gsta_gpio *chip = gc->private;
int nr = data->irq - chip->irq_base;
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
u32 val;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) {
val = readl(&regs->rimsc) & ~bit;
writel(val, &regs->rimsc);
}
if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) {
val = readl(&regs->fimsc) & ~bit;
writel(val, &regs->fimsc);
}
spin_unlock_irqrestore(&chip->lock, flags);
return;
}
static void gsta_irq_enable(struct irq_data *data)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
struct gsta_gpio *chip = gc->private;
int nr = data->irq - chip->irq_base;
struct gsta_regs __iomem *regs = chip->regs[nr / GSTA_GPIO_PER_BLOCK];
u32 bit = BIT(nr % GSTA_GPIO_PER_BLOCK);
u32 val;
int type;
unsigned long flags;
type = chip->irq_type[nr];
spin_lock_irqsave(&chip->lock, flags);
val = readl(&regs->rimsc);
if (type & IRQ_TYPE_EDGE_RISING)
writel(val | bit, &regs->rimsc);
else
writel(val & ~bit, &regs->rimsc);
val = readl(&regs->rimsc);
if (type & IRQ_TYPE_EDGE_FALLING)
writel(val | bit, &regs->fimsc);
else
writel(val & ~bit, &regs->fimsc);
spin_unlock_irqrestore(&chip->lock, flags);
return;
}
static int gsta_irq_type(struct irq_data *d, unsigned int type)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct gsta_gpio *chip = gc->private;
int nr = d->irq - chip->irq_base;
/* We only support edge interrupts */
if (!(type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))) {
pr_debug("%s: unsupported type 0x%x\n", __func__, type);
return -EINVAL;
}
chip->irq_type[nr] = type; /* used for enable/disable */
gsta_irq_enable(d);
return 0;
}
static irqreturn_t gsta_gpio_handler(int irq, void *dev_id)
{
struct gsta_gpio *chip = dev_id;
struct gsta_regs __iomem *regs;
u32 is;
int i, nr, base;
irqreturn_t ret = IRQ_NONE;
for (i = 0; i < GSTA_NR_BLOCKS; i++) {
regs = chip->regs[i];
base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK;
while ((is = readl(&regs->is))) {
nr = __ffs(is);
irq = base + nr;
generic_handle_irq(irq);
writel(1 << nr, &regs->ic);
ret = IRQ_HANDLED;
}
}
return ret;
}
static int gsta_alloc_irq_chip(struct gsta_gpio *chip)
{
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
int rv;
gc = devm_irq_alloc_generic_chip(chip->dev, KBUILD_MODNAME, 1,
chip->irq_base,
chip->reg_base, handle_simple_irq);
if (!gc)
return -ENOMEM;
gc->private = chip;
ct = gc->chip_types;
ct->chip.irq_set_type = gsta_irq_type;
ct->chip.irq_disable = gsta_irq_disable;
ct->chip.irq_enable = gsta_irq_enable;
/* FIXME: this makes at most 32 interrupts. Request 0 by now */
rv = devm_irq_setup_generic_chip(chip->dev, gc,
0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */,
0, IRQ_NOREQUEST | IRQ_NOPROBE, 0);
if (rv)
return rv;
/* Set up all all 128 interrupts: code from setup_generic_chip */
{
struct irq_chip_type *ct = gc->chip_types;
int i, j;
for (j = 0; j < GSTA_NR_GPIO; j++) {
i = chip->irq_base + j;
irq_set_chip_and_handler(i, &ct->chip, ct->handler);
irq_set_chip_data(i, gc);
irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
}
gc->irq_cnt = i - gc->irq_base;
}
return 0;
}
/* The platform device used here is instantiated by the MFD device */
static int gsta_probe(struct platform_device *dev)
{
int i, err;
struct pci_dev *pdev;
struct sta2x11_gpio_pdata *gpio_pdata;
struct gsta_gpio *chip;
pdev = *(struct pci_dev **)dev_get_platdata(&dev->dev);
gpio_pdata = dev_get_platdata(&pdev->dev);
if (gpio_pdata == NULL)
dev_err(&dev->dev, "no gpio config\n");
pr_debug("gpio config: %p\n", gpio_pdata);
chip = devm_kzalloc(&dev->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->dev = &dev->dev;
chip->reg_base = devm_platform_ioremap_resource(dev, 0);
if (IS_ERR(chip->reg_base))
return PTR_ERR(chip->reg_base);
for (i = 0; i < GSTA_NR_BLOCKS; i++) {
chip->regs[i] = chip->reg_base + i * 4096;
/* disable all irqs */
writel(0, &chip->regs[i]->rimsc);
writel(0, &chip->regs[i]->fimsc);
writel(~0, &chip->regs[i]->ic);
}
spin_lock_init(&chip->lock);
gsta_gpio_setup(chip);
if (gpio_pdata)
for (i = 0; i < GSTA_NR_GPIO; i++)
gsta_set_config(chip, i, gpio_pdata->pinconfig[i]);
/* 384 was used in previous code: be compatible for other drivers */
err = devm_irq_alloc_descs(&dev->dev, -1, 384,
GSTA_NR_GPIO, NUMA_NO_NODE);
if (err < 0) {
dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
-err);
return err;
}
chip->irq_base = err;
err = gsta_alloc_irq_chip(chip);
if (err)
return err;
err = devm_request_irq(&dev->dev, pdev->irq, gsta_gpio_handler,
IRQF_SHARED, KBUILD_MODNAME, chip);
if (err < 0) {
dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n",
-err);
return err;
}
err = devm_gpiochip_add_data(&dev->dev, &chip->gpio, chip);
if (err < 0) {
dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n",
-err);
return err;
}
platform_set_drvdata(dev, chip);
return 0;
}
static struct platform_driver sta2x11_gpio_platform_driver = {
.driver = {
.name = "sta2x11-gpio",
.suppress_bind_attrs = true,
},
.probe = gsta_probe,
};
builtin_platform_driver(sta2x11_gpio_platform_driver);