[PATCH 3/4] gpio: add ARM Primcell pl061 support
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Fri Oct 5 07:18:42 EDT 2012
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
arch/arm/Kconfig | 1 +
drivers/gpio/Kconfig | 6 ++
drivers/gpio/Makefile | 2 +
drivers/gpio/gpio-pl061.c | 168 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/amba/pl061.h | 16 +++++
5 files changed, 193 insertions(+)
create mode 100644 drivers/gpio/gpio-pl061.c
create mode 100644 include/linux/amba/pl061.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8278c82..f599d5b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -10,6 +10,7 @@ config ARM
config ARM_AMBA
bool
+ select GPIOLIB
config ARM_LINUX
bool
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index f03fbf6..a0e9b58 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -6,6 +6,12 @@ if GPIOLIB
menu "GPIO "
+config GPIO_PL061
+ bool "PrimeCell PL061 GPIO support"
+ depends on ARM_AMBA
+ help
+ Say yes here to support the PrimeCell PL061 GPIO device
+
config GPIO_STMPE
depends on I2C_STMPE
bool "STMPE GPIO Expander"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 945122b..e2e97d3 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -1,2 +1,4 @@
obj-$(CONFIG_GPIOLIB) += gpio.o
+
+obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
obj-$(CONFIG_GPIO_STMPE) += gpio-stmpe.o
diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
new file mode 100644
index 0000000..ff4c883
--- /dev/null
+++ b/drivers/gpio/gpio-pl061.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2008, 2009 Provigent Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
+ *
+ * Data sheet: ARM DDI 0190B, September 2000
+ */
+#include <common.h>
+#include <malloc.h>
+#include <errno.h>
+#include <io.h>
+#include <gpio.h>
+#include <init.h>
+
+#include <linux/amba/bus.h>
+#include <linux/amba/pl061.h>
+
+#define GPIODIR 0x400
+#define GPIOIS 0x404
+#define GPIOIBE 0x408
+#define GPIOIEV 0x40C
+#define GPIOIE 0x410
+#define GPIORIS 0x414
+#define GPIOMIS 0x418
+#define GPIOIC 0x41C
+
+#define PL061_GPIO_NR 8
+
+struct pl061_gpio {
+ void __iomem *base;
+ struct gpio_chip gc;
+};
+
+static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+ struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+ unsigned char gpiodir;
+
+ if (offset >= gc->ngpio)
+ return -EINVAL;
+
+ gpiodir = readb(chip->base + GPIODIR);
+ gpiodir &= ~(1 << offset);
+ writeb(gpiodir, chip->base + GPIODIR);
+
+ return 0;
+}
+
+static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
+ int value)
+{
+ struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+ unsigned char gpiodir;
+
+ if (offset >= gc->ngpio)
+ return -EINVAL;
+
+ writeb(!!value << offset, chip->base + (1 << (offset + 2)));
+ gpiodir = readb(chip->base + GPIODIR);
+ gpiodir |= 1 << offset;
+ writeb(gpiodir, chip->base + GPIODIR);
+
+ /*
+ * gpio value is set again, because pl061 doesn't allow to set value of
+ * a gpio pin before configuring it in OUT mode.
+ */
+ writeb(!!value << offset, chip->base + (1 << (offset + 2)));
+
+ return 0;
+}
+
+static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
+{
+ struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+
+ return !!readb(chip->base + (1 << (offset + 2)));
+}
+
+static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
+{
+ struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+
+ writeb(!!value << offset, chip->base + (1 << (offset + 2)));
+}
+
+static struct gpio_ops pl061_gpio_ops = {
+ .direction_input = pl061_direction_input,
+ .direction_output = pl061_direction_output,
+ .get = pl061_get_value,
+ .set = pl061_set_value,
+};
+
+static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
+{
+ struct pl061_platform_data *pdata;
+ struct pl061_gpio *chip;
+ int ret, i;
+
+ chip = xzalloc(sizeof(*chip));
+
+ pdata = dev->dev.platform_data;
+ if (pdata) {
+ chip->gc.base = pdata->gpio_base;
+ } else {
+ chip->gc.base = -1;
+ }
+
+ chip->base = amba_get_mem_region(dev);
+
+ chip->gc.ops = &pl061_gpio_ops;
+ chip->gc.ngpio = PL061_GPIO_NR;
+ chip->gc.dev = &dev->dev;
+
+ ret = gpiochip_add(&chip->gc);
+ if (ret) {
+ dev_err(&dev->dev, "couldn't add gpiochip\n");
+ goto free_mem;
+ }
+
+ writeb(0, chip->base + GPIOIE); /* disable irqs */
+
+ for (i = 0; i < PL061_GPIO_NR; i++) {
+ if (pdata) {
+ if (pdata->directions & (1 << i))
+ pl061_direction_output(&chip->gc, i,
+ pdata->values & (1 << i));
+ else
+ pl061_direction_input(&chip->gc, i);
+ }
+ }
+
+ return 0;
+
+free_mem:
+ kfree(chip);
+
+ return ret;
+}
+
+static struct amba_id pl061_ids[] = {
+ {
+ .id = 0x00041061,
+ .mask = 0x000fffff,
+ },
+ { 0, 0 },
+};
+
+static struct amba_driver pl061_gpio_driver = {
+ .drv = {
+ .name = "pl061_gpio",
+ },
+ .id_table = pl061_ids,
+ .probe = pl061_probe,
+};
+
+static int __init pl061_gpio_init(void)
+{
+ return amba_driver_register(&pl061_gpio_driver);
+}
+coredevice_initcall(pl061_gpio_init);
+
+MODULE_AUTHOR("Baruch Siach <baruch at tkos.co.il>");
+MODULE_DESCRIPTION("PL061 GPIO driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/amba/pl061.h b/include/linux/amba/pl061.h
new file mode 100644
index 0000000..fb83c04
--- /dev/null
+++ b/include/linux/amba/pl061.h
@@ -0,0 +1,16 @@
+#include <linux/types.h>
+
+/* platform data for the PL061 GPIO driver */
+
+struct pl061_platform_data {
+ /* number of the first GPIO */
+ unsigned gpio_base;
+
+ /* number of the first IRQ.
+ * If the IRQ functionality in not desired this must be set to 0.
+ */
+ unsigned irq_base;
+
+ u8 directions; /* startup directions, 1: out, 0: in */
+ u8 values; /* startup values */
+};
--
1.7.10.4
More information about the barebox
mailing list