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Subject[PATCH 3/4 v2] GPIO: add support for RDC321x GPIO controller
This patch adds a new GPIO driver for the RDC321x SoC GPIO controller.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
---
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index fee678f..dd10eb8 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -275,6 +275,14 @@ config GPIO_TIMBERDALE
---help---
Add support for the GPIO IP in the timberdale FPGA.

+config GPIO_RDC321X
+ tristate "RDC R-321x GPIO support"
+ depends on PCI && GPIOLIB
+ select MFD_RDC321X
+ help
+ Support for the RDC R321x SoC GPIOs over southbridge
+ PCI configuration space.
+
comment "SPI GPIO expanders:"

config GPIO_MAX7301
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 10f3f8d..d3226d3 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -27,4 +27,5 @@ obj-$(CONFIG_GPIO_VR41XX) += vr41xx_giu.o
obj-$(CONFIG_GPIO_WM831X) += wm831x-gpio.o
obj-$(CONFIG_GPIO_WM8350) += wm8350-gpiolib.o
obj-$(CONFIG_GPIO_WM8994) += wm8994-gpio.o
-obj-$(CONFIG_GPIO_SCH) += sch_gpio.o
\ No newline at end of file
+obj-$(CONFIG_GPIO_SCH) += sch_gpio.o
+obj-$(CONFIG_GPIO_RDC321X) += rdc321x-gpio.o
diff --git a/drivers/gpio/rdc321x-gpio.c b/drivers/gpio/rdc321x-gpio.c
new file mode 100644
index 0000000..545d333
--- /dev/null
+++ b/drivers/gpio/rdc321x-gpio.c
@@ -0,0 +1,237 @@
+/*
+ * RDC321x GPIO driver
+ *
+ * Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
+ * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/gpio.h>
+#include <linux/mfd/rdc321x.h>
+
+struct rdc321x_gpio {
+ spinlock_t lock;
+ u32 data_reg[2];
+ int reg1_ctrl_base;
+ int reg1_data_base;
+ int reg2_ctrl_base;
+ int reg2_data_base;
+ struct gpio_chip chip;
+};
+
+/* read GPIO pin */
+static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+ struct rdc321x_gpio *gpch =
+ container_of(chip, struct rdc321x_gpio, chip);
+ u32 value = 0;
+ int reg;
+
+ reg = gpio < 32 ? gpch->reg1_data_base : gpch->reg2_data_base;
+
+ spin_lock(&gpch->lock);
+ rdc321x_pci_write(reg, gpch->data_reg[gpio < 32 ? 0 : 1]);
+ rdc321x_pci_read(reg, &value);
+ spin_unlock(&gpch->lock);
+
+ return (1 << (gpio & 0x1f)) & value ? 1 : 0;
+}
+
+static void rdc_gpio_set_value_impl(struct gpio_chip *chip,
+ unsigned gpio, int value)
+{
+ struct rdc321x_gpio *gpch =
+ container_of(chip, struct rdc321x_gpio, chip);
+ int reg = (gpio < 32) ? 0 : 1;
+
+ if (value)
+ gpch->data_reg[reg] |= 1 << (gpio & 0x1f);
+ else
+ gpch->data_reg[reg] &= ~(1 << (gpio & 0x1f));
+
+ rdc321x_pci_write(reg ? gpch->reg1_data_base : gpch->reg2_data_base,
+ gpch->data_reg[reg]);
+}
+
+/* set GPIO pin to value */
+static void rdc_gpio_set_value(struct gpio_chip *chip,
+ unsigned gpio, int value)
+{
+ struct rdc321x_gpio *gpch =
+ container_of(chip, struct rdc321x_gpio, chip);
+ spin_lock(&gpch->lock);
+ rdc_gpio_set_value_impl(chip, gpio, value);
+ spin_unlock(&gpch->lock);
+}
+
+static int rdc_gpio_config(struct gpio_chip *chip,
+ unsigned gpio, int value)
+{
+ struct rdc321x_gpio *gpch =
+ container_of(chip, struct rdc321x_gpio, chip);
+ int err;
+ u32 reg;
+
+ spin_lock(&gpch->lock);
+ err = rdc321x_pci_read(gpio < 32 ?
+ gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, &reg);
+ if (err)
+ goto unlock;
+
+ reg |= 1 << (gpio & 0x1f);
+
+ err = rdc321x_pci_write(gpio < 32 ?
+ gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, reg);
+ if (err)
+ goto unlock;
+
+ rdc_gpio_set_value_impl(chip, gpio, value);
+
+unlock:
+ spin_unlock(&gpch->lock);
+
+ return err;
+}
+
+/* configure GPIO pin as input */
+static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+ return rdc_gpio_config(chip, gpio, 1);
+}
+
+/*
+ * Cache the initial value of both GPIO data registers
+ */
+static int __devinit rdc321x_gpio_probe(struct platform_device *pdev)
+{
+ int err;
+ struct resource *r;
+ struct rdc321x_gpio *rdc321x_gpio_dev;
+ struct rdc321x_gpio_pdata *pdata;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data supplied\n");
+ return -ENODEV;
+ }
+
+ rdc321x_gpio_dev = kzalloc(sizeof(struct rdc321x_gpio), GFP_KERNEL);
+ if (!rdc321x_gpio_dev) {
+ dev_err(&pdev->dev, "failed to allocate private data\n");
+ return -ENOMEM;
+ }
+
+ r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gpio-reg1");
+ if (!r) {
+ dev_err(&pdev->dev, "failed to get gpio-reg1 resource\n");
+ err = -ENODEV;
+ goto out_free;
+ }
+
+ rdc321x_gpio_dev->reg1_ctrl_base = r->start;
+ rdc321x_gpio_dev->reg1_data_base = r->start + 0x4;
+
+ r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gpio-reg2");
+ if (!r) {
+ dev_err(&pdev->dev, "failed to get gpio-reg2 resource\n");
+ err = -ENODEV;
+ goto out_free;
+ }
+
+ rdc321x_gpio_dev->reg2_ctrl_base = r->start;
+ rdc321x_gpio_dev->reg2_data_base = r->start + 0x4;
+
+ rdc321x_gpio_dev->chip.label = "rdc321x-gpio";
+ rdc321x_gpio_dev->chip.direction_input = rdc_gpio_direction_input;
+ rdc321x_gpio_dev->chip.direction_output = rdc_gpio_config;
+ rdc321x_gpio_dev->chip.get = rdc_gpio_get_value;
+ rdc321x_gpio_dev->chip.set = rdc_gpio_set_value;
+ rdc321x_gpio_dev->chip.base = 0;
+ rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios;
+
+ platform_set_drvdata(pdev, rdc321x_gpio_dev);
+
+ /* This might not be, what others (BIOS, bootloader, etc.)
+ wrote to these registers before, but it's a good guess. Still
+ better than just using 0xffffffff. */
+ err = rdc321x_pci_read(rdc321x_gpio_dev->reg1_data_base,
+ &rdc321x_gpio_dev->data_reg[0]);
+ if (err)
+ goto out_drvdata;
+
+ err = rdc321x_pci_read(rdc321x_gpio_dev->reg2_data_base,
+ &rdc321x_gpio_dev->data_reg[1]);
+ if (err)
+ goto out_drvdata;
+
+ spin_lock_init(&rdc321x_gpio_dev->lock);
+
+ printk(KERN_INFO "rdc321x-gpio: registering %d GPIOs\n",
+ rdc321x_gpio_dev->chip.ngpio);
+ return gpiochip_add(&rdc321x_gpio_dev->chip);
+
+out_drvdata:
+ platform_set_drvdata(pdev, NULL);
+out_free:
+ kfree(rdc321x_gpio_dev);
+ return err;
+}
+
+static int __devexit rdc321x_gpio_remove(struct platform_device *pdev)
+{
+ int ret;
+ struct rdc321x_gpio *rdc321x_gpio_dev = platform_get_drvdata(pdev);
+
+ ret = gpiochip_remove(&rdc321x_gpio_dev->chip);
+ if (ret)
+ dev_err(&pdev->dev, "failed to unregister chip\n");
+
+ kfree(rdc321x_gpio_dev);
+ platform_set_drvdata(pdev, NULL);
+
+ return ret;
+}
+
+static struct platform_driver rdc321x_gpio_driver = {
+ .driver.name = "rdc321x-gpio",
+ .driver.owner = THIS_MODULE,
+ .probe = rdc321x_gpio_probe,
+ .remove = __devexit_p(rdc321x_gpio_remove),
+};
+
+static int __init rdc321x_gpio_init(void)
+{
+ return platform_driver_register(&rdc321x_gpio_driver);
+}
+
+static void __exit rdc321x_gpio_exit(void)
+{
+ platform_driver_unregister(&rdc321x_gpio_driver);
+}
+
+module_init(rdc321x_gpio_init);
+module_exit(rdc321x_gpio_exit);
+
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_DESCRIPTION("RDC321x GPIO driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rdc321x-gpio");

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