gpio MIPS/OCTEON: Add a driver for OCTEON's on-chip GPIO pins.
The SOCs in the OCTEON family have 16 (or in some cases 20) on-chip
GPIO pins, this driver handles them all. Configuring the pins as
interrupt sources is handled elsewhere (OCTEON's irq handling code).
Signed-off-by: David Daney <david.daney@cavium.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5633/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/gpio/gpio-octeon.c b/drivers/gpio/gpio-octeon.c
new file mode 100644
index 0000000..71a4a31
--- /dev/null
+++ b/drivers/gpio/gpio-octeon.c
@@ -0,0 +1,157 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2011, 2012 Cavium Inc.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/octeon/cvmx-gpio-defs.h>
+
+#define RX_DAT 0x80
+#define TX_SET 0x88
+#define TX_CLEAR 0x90
+/*
+ * The address offset of the GPIO configuration register for a given
+ * line.
+ */
+static unsigned int bit_cfg_reg(unsigned int offset)
+{
+ /*
+ * The register stride is 8, with a discontinuity after the
+ * first 16.
+ */
+ if (offset < 16)
+ return 8 * offset;
+ else
+ return 8 * (offset - 16) + 0x100;
+}
+
+struct octeon_gpio {
+ struct gpio_chip chip;
+ u64 register_base;
+};
+
+static int octeon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
+{
+ struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
+
+ cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), 0);
+ return 0;
+}
+
+static void octeon_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
+ u64 mask = 1ull << offset;
+ u64 reg = gpio->register_base + (value ? TX_SET : TX_CLEAR);
+ cvmx_write_csr(reg, mask);
+}
+
+static int octeon_gpio_dir_out(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
+ union cvmx_gpio_bit_cfgx cfgx;
+
+ octeon_gpio_set(chip, offset, value);
+
+ cfgx.u64 = 0;
+ cfgx.s.tx_oe = 1;
+
+ cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), cfgx.u64);
+ return 0;
+}
+
+static int octeon_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
+ u64 read_bits = cvmx_read_csr(gpio->register_base + RX_DAT);
+
+ return ((1ull << offset) & read_bits) != 0;
+}
+
+static int octeon_gpio_probe(struct platform_device *pdev)
+{
+ struct octeon_gpio *gpio;
+ struct gpio_chip *chip;
+ struct resource *res_mem;
+ int err = 0;
+
+ gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+ chip = &gpio->chip;
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res_mem == NULL) {
+ dev_err(&pdev->dev, "found no memory resource\n");
+ err = -ENXIO;
+ goto out;
+ }
+ if (!devm_request_mem_region(&pdev->dev, res_mem->start,
+ resource_size(res_mem),
+ res_mem->name)) {
+ dev_err(&pdev->dev, "request_mem_region failed\n");
+ err = -ENXIO;
+ goto out;
+ }
+ gpio->register_base = (u64)devm_ioremap(&pdev->dev, res_mem->start,
+ resource_size(res_mem));
+
+ pdev->dev.platform_data = chip;
+ chip->label = "octeon-gpio";
+ chip->dev = &pdev->dev;
+ chip->owner = THIS_MODULE;
+ chip->base = 0;
+ chip->can_sleep = 0;
+ chip->ngpio = 20;
+ chip->direction_input = octeon_gpio_dir_in;
+ chip->get = octeon_gpio_get;
+ chip->direction_output = octeon_gpio_dir_out;
+ chip->set = octeon_gpio_set;
+ err = gpiochip_add(chip);
+ if (err)
+ goto out;
+
+ dev_info(&pdev->dev, "OCTEON GPIO driver probed.\n");
+out:
+ return err;
+}
+
+static int octeon_gpio_remove(struct platform_device *pdev)
+{
+ struct gpio_chip *chip = pdev->dev.platform_data;
+ return gpiochip_remove(chip);
+}
+
+static struct of_device_id octeon_gpio_match[] = {
+ {
+ .compatible = "cavium,octeon-3860-gpio",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, octeon_gpio_match);
+
+static struct platform_driver octeon_gpio_driver = {
+ .driver = {
+ .name = "octeon_gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = octeon_gpio_match,
+ },
+ .probe = octeon_gpio_probe,
+ .remove = octeon_gpio_remove,
+};
+
+module_platform_driver(octeon_gpio_driver);
+
+MODULE_DESCRIPTION("Cavium Inc. OCTEON GPIO Driver");
+MODULE_AUTHOR("David Daney");
+MODULE_LICENSE("GPL");