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path: root/drivers/gpio/gpio-brcmstb.c
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Diffstat (limited to 'drivers/gpio/gpio-brcmstb.c')
-rw-r--r--drivers/gpio/gpio-brcmstb.c260
1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
new file mode 100644
index 000000000..4630a8133
--- /dev/null
+++ b/drivers/gpio/gpio-brcmstb.c
@@ -0,0 +1,260 @@
+/*
+ * 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;
+
+ if (!priv) {
+ dev_err(&pdev->dev, "called %s without drvdata!\n", __func__);
+ return -EFAULT;
+ }
+
+ /*
+ * You can lose return values below, but we report all errors, and it's
+ * more important to actually perform all of the steps.
+ */
+ 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;
+ platform_set_drvdata(pdev, priv);
+ INIT_LIST_HEAD(&priv->bank_list);
+
+ 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;
+
+ 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);
+
+ 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");