linux/drivers/gpio/gpio-brcmstb.c

253 lines
6.6 KiB
C

/*
* Copyright (C) 2015 Broadcom Corporation
*
* 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.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/module.h>
#include <linux/basic_mmio_gpio.h>
#define GIO_BANK_SIZE 0x20
#define GIO_ODEN(bank) (((bank) * GIO_BANK_SIZE) + 0x00)
#define GIO_DATA(bank) (((bank) * GIO_BANK_SIZE) + 0x04)
#define GIO_IODIR(bank) (((bank) * GIO_BANK_SIZE) + 0x08)
#define GIO_EC(bank) (((bank) * GIO_BANK_SIZE) + 0x0c)
#define GIO_EI(bank) (((bank) * GIO_BANK_SIZE) + 0x10)
#define GIO_MASK(bank) (((bank) * GIO_BANK_SIZE) + 0x14)
#define GIO_LEVEL(bank) (((bank) * GIO_BANK_SIZE) + 0x18)
#define GIO_STAT(bank) (((bank) * GIO_BANK_SIZE) + 0x1c)
struct brcmstb_gpio_bank {
struct list_head node;
int id;
struct bgpio_chip bgc;
struct brcmstb_gpio_priv *parent_priv;
u32 width;
};
struct brcmstb_gpio_priv {
struct list_head bank_list;
void __iomem *reg_base;
int num_banks;
struct platform_device *pdev;
int gpio_base;
};
#define MAX_GPIO_PER_BANK 32
#define GPIO_BANK(gpio) ((gpio) >> 5)
/* assumes MAX_GPIO_PER_BANK is a multiple of 2 */
#define GPIO_BIT(gpio) ((gpio) & (MAX_GPIO_PER_BANK - 1))
static inline struct brcmstb_gpio_bank *
brcmstb_gpio_gc_to_bank(struct gpio_chip *gc)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
return container_of(bgc, struct brcmstb_gpio_bank, bgc);
}
static inline struct brcmstb_gpio_priv *
brcmstb_gpio_gc_to_priv(struct gpio_chip *gc)
{
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
return bank->parent_priv;
}
/* Make sure that the number of banks matches up between properties */
static int brcmstb_gpio_sanity_check_banks(struct device *dev,
struct device_node *np, struct resource *res)
{
int res_num_banks = resource_size(res) / GIO_BANK_SIZE;
int num_banks =
of_property_count_u32_elems(np, "brcm,gpio-bank-widths");
if (res_num_banks != num_banks) {
dev_err(dev, "Mismatch in banks: res had %d, bank-widths had %d\n",
res_num_banks, num_banks);
return -EINVAL;
} else {
return 0;
}
}
static int brcmstb_gpio_remove(struct platform_device *pdev)
{
struct brcmstb_gpio_priv *priv = platform_get_drvdata(pdev);
struct list_head *pos;
struct brcmstb_gpio_bank *bank;
int ret = 0;
list_for_each(pos, &priv->bank_list) {
bank = list_entry(pos, struct brcmstb_gpio_bank, node);
ret = bgpio_remove(&bank->bgc);
if (ret)
dev_err(&pdev->dev, "gpiochip_remove fail in cleanup");
}
return ret;
}
static int brcmstb_gpio_of_xlate(struct gpio_chip *gc,
const struct of_phandle_args *gpiospec, u32 *flags)
{
struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
int offset;
if (gc->of_gpio_n_cells != 2) {
WARN_ON(1);
return -EINVAL;
}
if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
return -EINVAL;
offset = gpiospec->args[0] - (gc->base - priv->gpio_base);
if (offset >= gc->ngpio)
return -EINVAL;
if (unlikely(offset >= bank->width)) {
dev_warn_ratelimited(&priv->pdev->dev,
"Received request for invalid GPIO offset %d\n",
gpiospec->args[0]);
}
if (flags)
*flags = gpiospec->args[1];
return offset;
}
static int brcmstb_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
void __iomem *reg_base;
struct brcmstb_gpio_priv *priv;
struct resource *res;
struct property *prop;
const __be32 *p;
u32 bank_width;
int err;
static int gpio_base;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
reg_base = devm_ioremap_resource(dev, res);
if (IS_ERR(reg_base))
return PTR_ERR(reg_base);
priv->gpio_base = gpio_base;
priv->reg_base = reg_base;
priv->pdev = pdev;
INIT_LIST_HEAD(&priv->bank_list);
if (brcmstb_gpio_sanity_check_banks(dev, np, res))
return -EINVAL;
of_property_for_each_u32(np, "brcm,gpio-bank-widths", prop, p,
bank_width) {
struct brcmstb_gpio_bank *bank;
struct bgpio_chip *bgc;
struct gpio_chip *gc;
bank = devm_kzalloc(dev, sizeof(*bank), GFP_KERNEL);
if (!bank) {
err = -ENOMEM;
goto fail;
}
bank->parent_priv = priv;
bank->id = priv->num_banks;
if (bank_width <= 0 || bank_width > MAX_GPIO_PER_BANK) {
dev_err(dev, "Invalid bank width %d\n", bank_width);
goto fail;
} else {
bank->width = bank_width;
}
/*
* Regs are 4 bytes wide, have data reg, no set/clear regs,
* and direction bits have 0 = output and 1 = input
*/
bgc = &bank->bgc;
err = bgpio_init(bgc, dev, 4,
reg_base + GIO_DATA(bank->id),
NULL, NULL, NULL,
reg_base + GIO_IODIR(bank->id), 0);
if (err) {
dev_err(dev, "bgpio_init() failed\n");
goto fail;
}
gc = &bgc->gc;
gc->of_node = np;
gc->owner = THIS_MODULE;
gc->label = np->full_name;
gc->base = gpio_base;
gc->of_gpio_n_cells = 2;
gc->of_xlate = brcmstb_gpio_of_xlate;
/* not all ngpio lines are valid, will use bank width later */
gc->ngpio = MAX_GPIO_PER_BANK;
err = gpiochip_add(gc);
if (err) {
dev_err(dev, "Could not add gpiochip for bank %d\n",
bank->id);
goto fail;
}
gpio_base += gc->ngpio;
dev_dbg(dev, "bank=%d, base=%d, ngpio=%d, width=%d\n", bank->id,
gc->base, gc->ngpio, bank->width);
/* Everything looks good, so add bank to list */
list_add(&bank->node, &priv->bank_list);
priv->num_banks++;
}
dev_info(dev, "Registered %d banks (GPIO(s): %d-%d)\n",
priv->num_banks, priv->gpio_base, gpio_base - 1);
platform_set_drvdata(pdev, priv);
return 0;
fail:
(void) brcmstb_gpio_remove(pdev);
return err;
}
static const struct of_device_id brcmstb_gpio_of_match[] = {
{ .compatible = "brcm,brcmstb-gpio" },
{},
};
MODULE_DEVICE_TABLE(of, brcmstb_gpio_of_match);
static struct platform_driver brcmstb_gpio_driver = {
.driver = {
.name = "brcmstb-gpio",
.of_match_table = brcmstb_gpio_of_match,
},
.probe = brcmstb_gpio_probe,
.remove = brcmstb_gpio_remove,
};
module_platform_driver(brcmstb_gpio_driver);
MODULE_AUTHOR("Gregory Fong");
MODULE_DESCRIPTION("Driver for Broadcom BRCMSTB SoC UPG GPIO");
MODULE_LICENSE("GPL v2");