Linux-libre 4.2-gnu

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");