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Diffstat (limited to 'drivers/gpio/gpio-hlwd.c')
-rw-r--r--drivers/gpio/gpio-hlwd.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-hlwd.c b/drivers/gpio/gpio-hlwd.c
new file mode 100644
index 000000000000..a63136a68ba3
--- /dev/null
+++ b/drivers/gpio/gpio-hlwd.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright (C) 2008-2009 The GameCube Linux Team
+// Copyright (C) 2008,2009 Albert Herranz
+// Copyright (C) 2017-2018 Jonathan Neuschäfer
+//
+// Nintendo Wii (Hollywood) GPIO driver
+
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+/*
+ * Register names and offsets courtesy of WiiBrew:
+ * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs
+ *
+ * Note that for most registers, there are two versions:
+ * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does
+ * always give access to all GPIO lines
+ * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory
+ * firewall (AHBPROT) in the Hollywood chipset has been configured to allow
+ * such access.
+ *
+ * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER
+ * register: A one bit configures the line for access via the HW_GPIOB_*
+ * registers, a zero bit indicates access via HW_GPIO_*. This driver uses
+ * HW_GPIOB_*.
+ */
+#define HW_GPIOB_OUT 0x00
+#define HW_GPIOB_DIR 0x04
+#define HW_GPIOB_IN 0x08
+#define HW_GPIOB_INTLVL 0x0c
+#define HW_GPIOB_INTFLAG 0x10
+#define HW_GPIOB_INTMASK 0x14
+#define HW_GPIOB_INMIR 0x18
+#define HW_GPIO_ENABLE 0x1c
+#define HW_GPIO_OUT 0x20
+#define HW_GPIO_DIR 0x24
+#define HW_GPIO_IN 0x28
+#define HW_GPIO_INTLVL 0x2c
+#define HW_GPIO_INTFLAG 0x30
+#define HW_GPIO_INTMASK 0x34
+#define HW_GPIO_INMIR 0x38
+#define HW_GPIO_OWNER 0x3c
+
+struct hlwd_gpio {
+ struct gpio_chip gpioc;
+ void __iomem *regs;
+};
+
+static int hlwd_gpio_probe(struct platform_device *pdev)
+{
+ struct hlwd_gpio *hlwd;
+ struct resource *regs_resource;
+ u32 ngpios;
+ int res;
+
+ hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL);
+ if (!hlwd)
+ return -ENOMEM;
+
+ regs_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ hlwd->regs = devm_ioremap_resource(&pdev->dev, regs_resource);
+ if (IS_ERR(hlwd->regs))
+ return PTR_ERR(hlwd->regs);
+
+ /*
+ * Claim all GPIOs using the OWNER register. This will not work on
+ * systems where the AHBPROT memory firewall hasn't been configured to
+ * permit PPC access to HW_GPIO_*.
+ *
+ * Note that this has to happen before bgpio_init reads the
+ * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong
+ * values.
+ */
+ iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER);
+
+ res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4,
+ hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT,
+ NULL, hlwd->regs + HW_GPIOB_DIR, NULL,
+ BGPIOF_BIG_ENDIAN_BYTE_ORDER);
+ if (res < 0) {
+ dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res);
+ return res;
+ }
+
+ res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios);
+ if (res)
+ ngpios = 32;
+ hlwd->gpioc.ngpio = ngpios;
+
+ return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd);
+}
+
+static const struct of_device_id hlwd_gpio_match[] = {
+ { .compatible = "nintendo,hollywood-gpio", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, hlwd_gpio_match);
+
+static struct platform_driver hlwd_gpio_driver = {
+ .driver = {
+ .name = "gpio-hlwd",
+ .of_match_table = hlwd_gpio_match,
+ },
+ .probe = hlwd_gpio_probe,
+};
+module_platform_driver(hlwd_gpio_driver);
+
+MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>");
+MODULE_DESCRIPTION("Nintendo Wii GPIO driver");
+MODULE_LICENSE("GPL");