[PATCH v3] powerpc: Basic GPIO support for GE Fanuc SBC610
Martyn Welch
martyn.welch at gefanuc.com
Sat Nov 8 00:00:15 EST 2008
Basic support for the GPIO available on the SBC610 VPX Single Board Computer
from GE Fanuc (PowerPC MPC8641D).
This patch adds basic support for the GPIO in the devices I/O FPGA, the GPIO
functionality is exposed through the AFIX pins on the backplane, unless used
by an AFIX card.
This code currently does not support switching between totem-pole and
open-drain outputs (when used as outputs, GPIOs default to totem-pole).
The interrupt capabilites of the GPIO lines is also not currently supported.
Signed-off-by: Martyn Welch <martyn.welch at gefanuc.com>
---
Anton: Thank you for your input.
The folowing changes have been made in version 3:
* Use 2 gpio-cells rather than 1 (Will be used in future)
* Added linux/compiler.h
* Removed un-needed debugging
* _gef_gpio_set changed from inline to static
* Corrected comment style
* Removed potential memory leak
* Made ".compatible" more specific (Not as generic as I had first thought)
* Simplified driver registration
arch/powerpc/boot/dts/gef_sbc610.dts | 6 +
arch/powerpc/platforms/86xx/Kconfig | 2
arch/powerpc/platforms/86xx/Makefile | 3 -
arch/powerpc/platforms/86xx/gef_gpio.c | 167 ++++++++++++++++++++++++++++++++
4 files changed, 177 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/boot/dts/gef_sbc610.dts b/arch/powerpc/boot/dts/gef_sbc610.dts
index 6ed6083..fd2b606 100644
--- a/arch/powerpc/boot/dts/gef_sbc610.dts
+++ b/arch/powerpc/boot/dts/gef_sbc610.dts
@@ -98,6 +98,12 @@
interrupt-parent = <&mpic>;
};
+ gef_gpio: gpio at 7,14000 {
+ #gpio-cells = <2>;
+ compatible = "gef,sbc610-gpio";
+ reg = <0x7 0x14000 0x24>;
+ gpio-controller;
+ };
};
soc at fef00000 {
diff --git a/arch/powerpc/platforms/86xx/Kconfig b/arch/powerpc/platforms/86xx/Kconfig
index 77dd797..8e56939 100644
--- a/arch/powerpc/platforms/86xx/Kconfig
+++ b/arch/powerpc/platforms/86xx/Kconfig
@@ -34,6 +34,8 @@ config MPC8610_HPCD
config GEF_SBC610
bool "GE Fanuc SBC610"
select DEFAULT_UIMAGE
+ select GENERIC_GPIO
+ select ARCH_REQUIRE_GPIOLIB
select HAS_RAPIDIO
help
This option enables support for GE Fanuc's SBC610.
diff --git a/arch/powerpc/platforms/86xx/Makefile b/arch/powerpc/platforms/86xx/Makefile
index 4a56ff6..31e540c 100644
--- a/arch/powerpc/platforms/86xx/Makefile
+++ b/arch/powerpc/platforms/86xx/Makefile
@@ -7,4 +7,5 @@ obj-$(CONFIG_SMP) += mpc86xx_smp.o
obj-$(CONFIG_MPC8641_HPCN) += mpc86xx_hpcn.o
obj-$(CONFIG_SBC8641D) += sbc8641d.o
obj-$(CONFIG_MPC8610_HPCD) += mpc8610_hpcd.o
-obj-$(CONFIG_GEF_SBC610) += gef_sbc610.o gef_pic.o
+gef-gpio-$(CONFIG_GPIOLIB) += gef_gpio.o
+obj-$(CONFIG_GEF_SBC610) += gef_sbc610.o gef_pic.o $(gef-gpio-y)
diff --git a/arch/powerpc/platforms/86xx/gef_gpio.c b/arch/powerpc/platforms/86xx/gef_gpio.c
new file mode 100644
index 0000000..352d131
--- /dev/null
+++ b/arch/powerpc/platforms/86xx/gef_gpio.c
@@ -0,0 +1,167 @@
+/*
+ * Driver for GE Fanuc's FPGA based GPIO pins
+ *
+ * Author: Martyn Welch <martyn.welch at gefanuc.com>
+ *
+ * 2008 (c) GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+/* TODO
+ *
+ * Configuration of output modes (totem-pole/open-drain)
+ * Interrupt configuration - interrupts are always generated the FPGA relies on
+ * the I/O interrupt controllers mask to stop them propergating
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+
+#define GEF_GPIO_DIRECT 0x00
+#define GEF_GPIO_IN 0x04
+#define GEF_GPIO_OUT 0x08
+#define GEF_GPIO_TRIG 0x0C
+#define GEF_GPIO_POLAR_A 0x10
+#define GEF_GPIO_POLAR_B 0x14
+#define GEF_GPIO_INT_STAT 0x18
+#define GEF_GPIO_OVERRUN 0x1C
+#define GEF_GPIO_MODE 0x20
+
+#define NUM_GPIO 19
+
+/* Let's create a common inlined function to commonise the code and so we don't
+ * have to resolve the chip structure multiple times.
+ */
+static void _gef_gpio_set(void __iomem *reg, unsigned int offset, int value)
+{
+ unsigned int data;
+
+ data = ioread32be(reg);
+ /* value: 0=low; 1=high */
+ if (value & 0x1)
+ data = data | (0x1 << offset);
+ else
+ data = data & ~(0x1 << offset);
+
+ iowrite32be(data, reg);
+}
+
+
+static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
+{
+ struct of_mm_gpio_chip *mmchip;
+ unsigned int data;
+
+ /* Find memory mapped gpio chip structure from gpio_chip, this contains
+ * the mapped location of the GPIO controller
+ */
+ mmchip = to_of_mm_gpio_chip(chip);
+
+ data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
+ data = data | (0x1 << offset);
+ iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
+
+ return 0;
+}
+
+static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct of_mm_gpio_chip *mmchip;
+ unsigned int data;
+
+ /* Find memory mapped gpio chip structure from gpio_chip, this contains
+ * the mapped location of the GPIO controller
+ */
+ mmchip = to_of_mm_gpio_chip(chip);
+
+ /* Set direction before switching to input */
+ _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
+
+ data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
+ data = data & ~(0x1 << offset);
+ iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
+
+ return 0;
+}
+
+static int gef_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct of_mm_gpio_chip *mmchip;
+ unsigned int data;
+ int state = 0;
+
+ /* Find memory mapped gpio chip structure from gpio_chip, this contains
+ * the mapped location of the GPIO controller
+ */
+ mmchip = to_of_mm_gpio_chip(chip);
+
+ data = ioread32be(mmchip->regs + GEF_GPIO_IN);
+ state = (int)((data >> offset) & 0x1);
+
+ return state;
+}
+
+static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct of_mm_gpio_chip *mmchip;
+
+ /* Find memory mapped gpio chip structure from gpio_chip, this contains
+ * the mapped location of the GPIO controller
+ */
+ mmchip = to_of_mm_gpio_chip(chip);
+
+ _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
+
+}
+
+static int __init gef_gpio_init(void)
+{
+ struct device_node *np;
+
+ for_each_compatible_node(np, NULL, "gef,sbc610-gpio") {
+ int retval;
+ struct of_mm_gpio_chip *gef_gpio_chip;
+
+ pr_debug("%s: Initialising GEF GPIO\n", np->full_name);
+
+ /* Allocate chip structure */
+ gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL);
+ if (!gef_gpio_chip) {
+ pr_err("%s: Unable to allocate structure\n",
+ np->full_name);
+ continue;
+ }
+
+ /* Setup pointers to chip functions */
+ gef_gpio_chip->of_gc.gpio_cells = 2;
+ gef_gpio_chip->of_gc.gc.ngpio = NUM_GPIO;
+ gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in;
+ gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out;
+ gef_gpio_chip->of_gc.gc.get = gef_gpio_get;
+ gef_gpio_chip->of_gc.gc.set = gef_gpio_set;
+
+ /* This function adds a memory mapped GPIO chip */
+ retval = of_mm_gpiochip_add(np, gef_gpio_chip);
+ if (retval) {
+ kfree(gef_gpio_chip);
+ pr_err("%s: Unable to add GPIO\n", np->full_name);
+ }
+ }
+
+ return 0;
+};
+arch_initcall(gef_gpio_init);
+
+MODULE_DESCRIPTION("GE Fanuc I/O FPGA GPIO driver");
+MODULE_AUTHOR("Martyn Welch <martyn.welch at gefanuc.com");
+MODULE_LICENSE("GPL");
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