linux/drivers/gpio/gpio-creg-snps.c
Andy Shevchenko 45a541a610 gpio: Setup parent device and get rid of unnecessary of_node assignment
Some of the drivers do not set parent device. This may lead to obstacles
during debugging or understanding the device relations from the Linux
point of view. Assign parent device for GPIO chips created by these
drivers.

While at it, let GPIO library to assign of_node from the parent device.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-12-17 17:44:19 +01:00

190 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
//
// Synopsys CREG (Control REGisters) GPIO driver
//
// Copyright (C) 2018 Synopsys
// Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#define MAX_GPIO 32
struct creg_layout {
u8 ngpio;
u8 shift[MAX_GPIO];
u8 on[MAX_GPIO];
u8 off[MAX_GPIO];
u8 bit_per_gpio[MAX_GPIO];
};
struct creg_gpio {
struct gpio_chip gc;
void __iomem *regs;
spinlock_t lock;
const struct creg_layout *layout;
};
static void creg_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
struct creg_gpio *hcg = gpiochip_get_data(gc);
const struct creg_layout *layout = hcg->layout;
u32 reg, reg_shift, value;
unsigned long flags;
int i;
value = val ? hcg->layout->on[offset] : hcg->layout->off[offset];
reg_shift = layout->shift[offset];
for (i = 0; i < offset; i++)
reg_shift += layout->bit_per_gpio[i] + layout->shift[i];
spin_lock_irqsave(&hcg->lock, flags);
reg = readl(hcg->regs);
reg &= ~(GENMASK(layout->bit_per_gpio[i] - 1, 0) << reg_shift);
reg |= (value << reg_shift);
writel(reg, hcg->regs);
spin_unlock_irqrestore(&hcg->lock, flags);
}
static int creg_gpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val)
{
creg_gpio_set(gc, offset, val);
return 0;
}
static int creg_gpio_validate_pg(struct device *dev, struct creg_gpio *hcg,
int i)
{
const struct creg_layout *layout = hcg->layout;
if (layout->bit_per_gpio[i] < 1 || layout->bit_per_gpio[i] > 8)
return -EINVAL;
/* Check that on value fits its placeholder */
if (GENMASK(31, layout->bit_per_gpio[i]) & layout->on[i])
return -EINVAL;
/* Check that off value fits its placeholder */
if (GENMASK(31, layout->bit_per_gpio[i]) & layout->off[i])
return -EINVAL;
if (layout->on[i] == layout->off[i])
return -EINVAL;
return 0;
}
static int creg_gpio_validate(struct device *dev, struct creg_gpio *hcg,
u32 ngpios)
{
u32 reg_len = 0;
int i;
if (hcg->layout->ngpio < 1 || hcg->layout->ngpio > MAX_GPIO)
return -EINVAL;
if (ngpios < 1 || ngpios > hcg->layout->ngpio) {
dev_err(dev, "ngpios must be in [1:%u]\n", hcg->layout->ngpio);
return -EINVAL;
}
for (i = 0; i < hcg->layout->ngpio; i++) {
if (creg_gpio_validate_pg(dev, hcg, i))
return -EINVAL;
reg_len += hcg->layout->shift[i] + hcg->layout->bit_per_gpio[i];
}
/* Check that we fit in 32 bit register */
if (reg_len > 32)
return -EINVAL;
return 0;
}
static const struct creg_layout hsdk_cs_ctl = {
.ngpio = 10,
.shift = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
.off = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 },
.on = { 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 },
.bit_per_gpio = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 }
};
static const struct creg_layout axs10x_flsh_cs_ctl = {
.ngpio = 1,
.shift = { 0 },
.off = { 1 },
.on = { 3 },
.bit_per_gpio = { 2 }
};
static const struct of_device_id creg_gpio_ids[] = {
{
.compatible = "snps,creg-gpio-axs10x",
.data = &axs10x_flsh_cs_ctl
}, {
.compatible = "snps,creg-gpio-hsdk",
.data = &hsdk_cs_ctl
}, { /* sentinel */ }
};
static int creg_gpio_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
struct device *dev = &pdev->dev;
struct creg_gpio *hcg;
u32 ngpios;
int ret;
hcg = devm_kzalloc(dev, sizeof(struct creg_gpio), GFP_KERNEL);
if (!hcg)
return -ENOMEM;
hcg->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hcg->regs))
return PTR_ERR(hcg->regs);
match = of_match_node(creg_gpio_ids, pdev->dev.of_node);
hcg->layout = match->data;
if (!hcg->layout)
return -EINVAL;
ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
if (ret)
return ret;
ret = creg_gpio_validate(dev, hcg, ngpios);
if (ret)
return ret;
spin_lock_init(&hcg->lock);
hcg->gc.parent = dev;
hcg->gc.label = dev_name(dev);
hcg->gc.base = -1;
hcg->gc.ngpio = ngpios;
hcg->gc.set = creg_gpio_set;
hcg->gc.direction_output = creg_gpio_dir_out;
ret = devm_gpiochip_add_data(dev, &hcg->gc, hcg);
if (ret)
return ret;
dev_info(dev, "GPIO controller with %d gpios probed\n", ngpios);
return 0;
}
static struct platform_driver creg_gpio_snps_driver = {
.driver = {
.name = "snps-creg-gpio",
.of_match_table = creg_gpio_ids,
},
.probe = creg_gpio_probe,
};
builtin_platform_driver(creg_gpio_snps_driver);