[PATCH] powerpc/4xx: Add 4xx gpio support
Stefan Roese
sr at denx.de
Fri Oct 10 01:53:34 EST 2008
This patch adds a 4xx gpio driver. Tested on a 405EP and a 440EPx
platform.
Signed-off-by: Stefan Roese <sr at denx.de>
---
This driver probably needs some final polishing. E.g. some parts can
be extraced from ppc4xx_gpio_dir_in()/ppc4xx_gpio_dir_out() and moved
into seperate functions to make the code more compact. Also some
documentation would be handy. I didn't include it for now since I
wanted this driver version out now for comments. Documentation
will follow in a later version.
Other suggestion are welcome. :)
arch/powerpc/sysdev/Kconfig | 8 ++
arch/powerpc/sysdev/Makefile | 1 +
arch/powerpc/sysdev/ppc4xx_gpio.c | 233 +++++++++++++++++++++++++++++++++++++
3 files changed, 242 insertions(+), 0 deletions(-)
create mode 100644 arch/powerpc/sysdev/ppc4xx_gpio.c
diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index 72fb35b..f4a8edb 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -6,3 +6,11 @@ config PPC4xx_PCI_EXPRESS
bool
depends on PCI && 4xx
default n
+
+config PPC4xx_GPIO
+ bool "PPC4xx GPIO support"
+ depends on 4xx
+ select ARCH_REQUIRE_GPIOLIB
+ select GENERIC_GPIO
+ help
+ Enable gpiolib support for PPC4xx based boards
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index a90054b..35d5765 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_OF_RTC) += of_rtc.o
ifeq ($(CONFIG_PCI),y)
obj-$(CONFIG_4xx) += ppc4xx_pci.o
endif
+obj-$(CONFIG_PPC4xx_GPIO) += ppc4xx_gpio.o
# Temporary hack until we have migrated to asm-powerpc
ifeq ($(ARCH),powerpc)
diff --git a/arch/powerpc/sysdev/ppc4xx_gpio.c b/arch/powerpc/sysdev/ppc4xx_gpio.c
new file mode 100644
index 0000000..9847579
--- /dev/null
+++ b/arch/powerpc/sysdev/ppc4xx_gpio.c
@@ -0,1 +1,233 @@
+/*
+ * IBM/AMCC PPC4xx GPIO LIB API implementation
+ *
+ * Copyright 2008 Stefan Roese <sr at denx.de>, DENX Software Engineering
+ *
+ * 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.
+ */
+
+#undef DEBUG
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
+
+#include <asm/dcr.h>
+#include <asm/dcr-regs.h>
+#include <asm/reg.h>
+#include <asm/io.h>
+
+#define GPIO_ALT1_SEL 0x40000000
+#define GPIO_ALT2_SEL 0x80000000
+#define GPIO_ALT3_SEL 0xc0000000
+#define GPIO_IN_SEL 0x40000000
+#define GPIO_MASK 0xc0000000
+
+#define GPIO_MAX 32
+#define GPIO_VAL(gpio) (0x80000000 >> (gpio))
+
+struct ppc4xx_gpio {
+ u32 or; /* 0x00: Output */
+ u32 tcr; /* 0x04: Three-State Control */
+ u32 osrl; /* 0x08: Output Select (Low) */
+ u32 osrh; /* 0x0c: Output Select (High) */
+ u32 tsrl; /* 0x10: Three-State Select (Low) */
+ u32 tsrh; /* 0x14: Three-State Select (High) */
+ u32 odr; /* 0x18: Open Drain */
+ u32 ir; /* 0x1c: Input */
+ u32 rr1; /* 0x20: Receive Register 1 */
+ u32 rr2; /* 0x24: Receive Register 2 */
+ u32 rr3; /* 0x28: Receive Register 3 */
+ u32 res;
+ u32 isr1l; /* 0x30: Input Select 1 (Low) */
+ u32 isr1h; /* 0x34: Input Select 1 (High) */
+ u32 isr2l; /* 0x38: Input Select 1 (Low) */
+ u32 isr2h; /* 0x3c: Input Select 1 (High) */
+ u32 isr3l; /* 0x40: Input Select 1 (Low) */
+ u32 isr3h; /* 0x44: Input Select 1 (High) */
+};
+
+struct ppc4xx_gpio_chip {
+ struct of_mm_gpio_chip mmchip;
+ spinlock_t lock;
+};
+
+static inline struct ppc4xx_gpio_chip *
+to_ppc4xx_gpio_chip(struct of_mm_gpio_chip *mm_gc)
+{
+ return container_of(mm_gc, struct ppc4xx_gpio_chip, mmchip);
+}
+
+static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+
+ return (in_be32(®s->ir) & GPIO_VAL(gpio) ? 1 : 0);
+}
+
+static inline void __ppc4xx_gpio_set(struct gpio_chip *gc,
+ unsigned int gpio, int val)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+
+ if (val)
+ out_be32(®s->or, in_be32(®s->or) | GPIO_VAL(gpio));
+ else
+ out_be32(®s->or, in_be32(®s->or) & ~GPIO_VAL(gpio));
+}
+
+static void ppc4xx_gpio_set(struct gpio_chip *gc,
+ unsigned int gpio, int val)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpio_chip(mm_gc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+ __ppc4xx_gpio_set(gc, gpio, val);
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
+}
+
+static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpio_chip(mm_gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+ unsigned long flags;
+ u32 offs, mask, mask2, val32;
+ u32 gpio2 = 0;
+
+ spin_lock_irqsave(&chip->lock, flags);
+
+ if (gpio >= GPIO_MAX / 2) {
+ offs = 0x4;
+ gpio2 = (gpio - GPIO_MAX / 2) << 1;
+ }
+
+ mask = 0x80000000 >> gpio;
+ mask2 = 0xc0000000 >> gpio2;
+
+ /* first set TCR to 0 */
+ out_be32(®s->tcr, in_be32(®s->tcr) & ~mask);
+
+ /* now set the direction */
+ val32 = in_be32(®s->isr1l + offs) & ~mask2;
+ val32 |= GPIO_IN_SEL >> gpio2;
+ out_be32(®s->isr1l + offs, val32);
+
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ return 0;
+}
+
+static int ppc4xx_gpio_dir_out(struct gpio_chip *gc,
+ unsigned int gpio, int val)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpio_chip(mm_gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+ unsigned long flags;
+ u32 offs, mask, mask2, val32;
+ u32 gpio2 = 0;
+
+ spin_lock_irqsave(&chip->lock, flags);
+
+ if (gpio >= GPIO_MAX / 2) {
+ offs = 0x4;
+ gpio2 = (gpio - GPIO_MAX / 2) << 1;
+ }
+
+ mask = 0x80000000 >> gpio;
+ mask2 = 0xc0000000 >> gpio2;
+
+ /* first set TCR to 0 */
+ out_be32(®s->tcr, in_be32(®s->tcr) & ~mask);
+
+ /* set initial value */
+ __ppc4xx_gpio_set(gc, gpio, val);
+
+ /* now set the direction */
+ val32 = in_be32(®s->osrl + offs) & ~mask2;
+ out_be32(®s->osrl + offs, val32);
+
+ /* now configure TCR to drive output */
+ out_be32(®s->tcr, in_be32(®s->tcr) | mask);
+
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
+
+ return 0;
+}
+
+static int __devinit ppc4xx_gpiochip_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
+{
+ struct ppc4xx_gpio_chip *chip;
+ struct of_gpio_chip *ofchip;
+ int ret;
+
+ chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ ofchip = &chip->mmchip.of_gc;
+
+ spin_lock_init(&chip->lock);
+
+ ofchip->gpio_cells = 2;
+ ofchip->gc.ngpio = 32;
+ ofchip->gc.direction_input = ppc4xx_gpio_dir_in;
+ ofchip->gc.direction_output = ppc4xx_gpio_dir_out;
+ ofchip->gc.get = ppc4xx_gpio_get;
+ ofchip->gc.set = ppc4xx_gpio_set;
+
+ ret = of_mm_gpiochip_add(ofdev->node, &chip->mmchip);
+ if (ret) {
+ free(chip);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ppc4xx_gpiochip_remove(struct of_device *ofdev)
+{
+ return -EBUSY;
+}
+
+static const struct of_device_id ppc4xx_gpiochip_match[] = {
+ {
+ .compatible = "ibm,gpio",
+ },
+ {}
+};
+
+static struct of_platform_driver ppc4xx_gpiochip_driver = {
+ .name = "gpio",
+ .match_table = ppc4xx_gpiochip_match,
+ .probe = ppc4xx_gpiochip_probe,
+ .remove = ppc4xx_gpiochip_remove,
+};
+
+static int __init ppc4xx_gpio_init(void)
+{
+ if (of_register_platform_driver(&ppc4xx_gpiochip_driver))
+ printk(KERN_ERR "%s: Unable to register GPIO driver\n", __func__);
+
+ return 0;
+}
+arch_initcall(ppc4xx_gpio_init);
--
1.6.0.2
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