diff options
Diffstat (limited to 'drivers/gpio/gpio-brcmstb.c')
| -rw-r--r-- | drivers/gpio/gpio-brcmstb.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c new file mode 100644 index 000000000000..7a3cb1fa0a76 --- /dev/null +++ b/drivers/gpio/gpio-brcmstb.c @@ -0,0 +1,252 @@ +/* + * 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"); |