[PATCH 8/8] powerpc/5200: Rework GPT driver to also be an IRQ controller
Grant Likely
grant.likely at secretlab.ca
Thu Jan 22 07:55:46 EST 2009
From: Grant Likely <grant.likely at secretlab.ca>
This patch adds IRQ controller support to the MPC5200 General
Purpose Timer (GPT) device driver. With this patch the mpc5200-gpt
driver supports both GPIO and IRQ functions.
The GPT driver was contained within the mpc52xx_gpio.c file, but this
patch moves it out into a new file (mpc52xx_gpt.c) since it has more
than just GPIO functionality now and it was only grouped with the
mpc52xx-gpio drivers as a matter of convenience before. Also, this
driver will most likely get extended again to also provide support
for the timer function.
Implementation node: Alternately, I could have tried to implement
the IRQ support as a separate driver and left the GPIO portion alone.
However, multiple functions of this device (ie. GPIO input+interrupt
controller, or timer+GPIO) can be active at the same time and the
registers are shared so it is safer to contain all functionality
within a single driver.
Signed-off-by: Grant Likely <grant.likely at secretlab.ca>
CC: Sascha Hauer <s.hauer at pengutronix.de>
CC: Wolfram Sang <w.sang at pengutronix.de>
CC: linuxppc-dev at ozlabs.org
---
arch/powerpc/platforms/52xx/Makefile | 2
arch/powerpc/platforms/52xx/mpc52xx_gpio.c | 85 ------
arch/powerpc/platforms/52xx/mpc52xx_gpt.c | 429 ++++++++++++++++++++++++++++
3 files changed, 430 insertions(+), 86 deletions(-)
create mode 100644 arch/powerpc/platforms/52xx/mpc52xx_gpt.c
diff --git a/arch/powerpc/platforms/52xx/Makefile b/arch/powerpc/platforms/52xx/Makefile
index 9dfbde2..bfd4f52 100644
--- a/arch/powerpc/platforms/52xx/Makefile
+++ b/arch/powerpc/platforms/52xx/Makefile
@@ -1,7 +1,7 @@
#
# Makefile for 52xx based boards
#
-obj-y += mpc52xx_pic.o mpc52xx_common.o
+obj-y += mpc52xx_pic.o mpc52xx_common.o mpc52xx_gpt.o
obj-$(CONFIG_PCI) += mpc52xx_pci.o
obj-$(CONFIG_PPC_MPC5200_SIMPLE) += mpc5200_simple.o
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpio.c b/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
index 07f89ae..2b8d8ef 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
@@ -354,88 +354,6 @@ static struct of_platform_driver mpc52xx_simple_gpiochip_driver = {
.remove = mpc52xx_gpiochip_remove,
};
-/*
- * GPIO LIB API implementation for gpt GPIOs.
- *
- * Each gpt only has a single GPIO.
- */
-static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio)
-{
- struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
- struct mpc52xx_gpt __iomem *regs = mm_gc->regs;
-
- return (in_be32(®s->status) & (1 << (31 - 23))) ? 1 : 0;
-}
-
-static void
-mpc52xx_gpt_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 mpc52xx_gpt __iomem *regs = mm_gc->regs;
-
- if (val)
- out_be32(®s->mode, 0x34);
- else
- out_be32(®s->mode, 0x24);
-
- pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
-}
-
-static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
-{
- struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
- struct mpc52xx_gpt __iomem *regs = mm_gc->regs;
-
- out_be32(®s->mode, 0x04);
-
- return 0;
-}
-
-static int
-mpc52xx_gpt_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
-{
- mpc52xx_gpt_gpio_set(gc, gpio, val);
- pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
-
- return 0;
-}
-
-static int __devinit mpc52xx_gpt_gpiochip_probe(struct of_device *ofdev,
- const struct of_device_id *match)
-{
- struct of_mm_gpio_chip *mmchip;
- struct of_gpio_chip *chip;
-
- mmchip = kzalloc(sizeof(*mmchip), GFP_KERNEL);
- if (!mmchip)
- return -ENOMEM;
-
- chip = &mmchip->of_gc;
-
- chip->gpio_cells = 2;
- chip->gc.ngpio = 1;
- chip->gc.direction_input = mpc52xx_gpt_gpio_dir_in;
- chip->gc.direction_output = mpc52xx_gpt_gpio_dir_out;
- chip->gc.get = mpc52xx_gpt_gpio_get;
- chip->gc.set = mpc52xx_gpt_gpio_set;
-
- return of_mm_gpiochip_add(ofdev->node, mmchip);
-}
-
-static const struct of_device_id mpc52xx_gpt_gpiochip_match[] = {
- {
- .compatible = "fsl,mpc5200-gpt-gpio",
- },
- {}
-};
-
-static struct of_platform_driver mpc52xx_gpt_gpiochip_driver = {
- .name = "gpio_gpt",
- .match_table = mpc52xx_gpt_gpiochip_match,
- .probe = mpc52xx_gpt_gpiochip_probe,
- .remove = mpc52xx_gpiochip_remove,
-};
-
static int __init mpc52xx_gpio_init(void)
{
if (of_register_platform_driver(&mpc52xx_wkup_gpiochip_driver))
@@ -444,9 +362,6 @@ static int __init mpc52xx_gpio_init(void)
if (of_register_platform_driver(&mpc52xx_simple_gpiochip_driver))
printk(KERN_ERR "Unable to register simple GPIO driver\n");
- if (of_register_platform_driver(&mpc52xx_gpt_gpiochip_driver))
- printk(KERN_ERR "Unable to register gpt GPIO driver\n");
-
return 0;
}
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
new file mode 100644
index 0000000..612a8a3
--- /dev/null
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -0,0 +1,429 @@
+/*
+ * MPC5200 General Purpose Timer device driver
+ *
+ * Copyright (c) 2009 Secret Lab Technologies Ltd.
+ * Copyright (c) 2008 Sascha Hauer <s.hauer at pengutronix.de>, Pengutronix
+ *
+ * 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 file is a driver for the the General Purpose Timer (gpt) devices
+ * found on the MPC5200 SoC. Each timer has an IO pin which can be used
+ * for GPIO or can be used to raise interrupts. The timer function can
+ * be used independently from the IO pin, or it can be used to control
+ * output signals or measure input signals.
+ *
+ * This driver supports the GPIO and IRQ controller functions of the GPT
+ * device. Timer functions are not yet supported, nor is the watchdog
+ * timer.
+ *
+ * To use the GPIO function, the following two properties must be added
+ * to the device tree node for the gpt device (typically in the .dts file
+ * for the board):
+ * gpio-controller;
+ * #gpio-cells = < 2 >;
+ * This driver will register the GPIO pin if it finds the gpio-controller
+ * property in the device tree.
+ *
+ * To use the IRQ controller function, the following two properties must
+ * be added to the device tree node for the gpt device:
+ * interrupt-controller;
+ * #interrupt-cells = < 1 >;
+ * The IRQ controller binding only uses one cell to specify the interrupt,
+ * and the IRQ flags are encoded in the cell. A cell is not used to encode
+ * the IRQ number because the GPT only has a single IRQ source. For flags,
+ * a value of '1' means rising edge sensitive and '2' means falling edge.
+ *
+ * The GPIO and the IRQ controller functions can be used at the same time,
+ * but in this use case the IO line will only work as an input. Trying to
+ * use it as a GPIO output will not work.
+ *
+ * When using the GPIO line as an output, it can either be driven as normal
+ * IO, or it can be an OC output. At the moment it is the responsibility
+ * of the bootloader or the platform setup code to set the output mode.
+ * This driver does not change the output mode setting.
+ */
+
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/kernel.h>
+
+#include <asm/time.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/mpc52xx.h>
+
+MODULE_DESCRIPTION("Freescale MPC52xx gpt driver");
+MODULE_AUTHOR("Sascha Hauer, Grant Likely");
+MODULE_LICENSE("GPL");
+
+/**
+ * struct mpc52xx_gpt - Private data structure for MPC52xx GPT driver
+ * @dev: pointer to device structure
+ * @regs: virtual address of GPT registers
+ * @of_gc: of_gpio_chip instance structure; used when GPIO is enabled
+ * @irqhost: Pointer to irq_host instance; used when IRQ mode is supported
+ */
+struct mpc52xx_gpt_priv {
+ struct device *dev;
+ struct mpc52xx_gpt __iomem *regs;
+ spinlock_t lock;
+ struct of_gpio_chip of_gc;
+ struct irq_host *irqhost;
+};
+
+#define MPC52xx_GPT_GPIO_MODE_MASK 0x00000030
+#define MPC52xx_GPT_GPIO_MODE_OUTPUT 0x00000020
+#define MPC52xx_GPT_GPIO_OUTPUT_HIGH 0x00000010
+
+/* ---------------------------------------------------------------------
+ * Cascaded interrupt controller hooks
+ */
+
+static void mpc52xx_gpt_irq_unmask(unsigned int virq)
+{
+ struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpt->lock, flags);
+ out_be32(&gpt->regs->mode, in_be32(&gpt->regs->mode) | 0x100);
+ spin_unlock_irqrestore(&gpt->lock, flags);
+}
+
+static void mpc52xx_gpt_irq_mask(unsigned int virq)
+{
+ struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpt->lock, flags);
+ out_be32(&gpt->regs->mode, in_be32(&gpt->regs->mode) & ~0x100);
+ spin_unlock_irqrestore(&gpt->lock, flags);
+}
+
+static void mpc52xx_gpt_irq_ack(unsigned int virq)
+{
+ struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
+
+ out_be32(&gpt->regs->status, 0xf);
+}
+
+static int mpc52xx_gpt_irq_set_type(unsigned int virq, unsigned int flow_type)
+{
+ struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
+ unsigned long flags;
+ u32 reg;
+
+ dev_dbg(gpt->dev, "%s: virq=%i type=%x\n", __func__, virq, flow_type);
+
+ spin_lock_irqsave(&gpt->lock, flags);
+ reg = in_be32(&gpt->regs->mode) & ~0x30000;
+ if (flow_type & IRQF_TRIGGER_RISING)
+ reg |= 0x10000;
+ if (flow_type & IRQF_TRIGGER_FALLING)
+ reg |= 0x20000;
+ out_be32(&gpt->regs->mode, reg);
+ spin_unlock_irqrestore(&gpt->lock, flags);
+
+ return 0;
+}
+
+static struct irq_chip mpc52xx_gpt_irq_chip = {
+ .typename = "MPC52xx GPT",
+ .unmask = mpc52xx_gpt_irq_unmask,
+ .mask = mpc52xx_gpt_irq_mask,
+ .ack = mpc52xx_gpt_irq_ack,
+ .set_type = mpc52xx_gpt_irq_set_type,
+};
+
+void mpc52xx_gpt_irq_cascade(unsigned int virq, struct irq_desc *desc)
+{
+ struct mpc52xx_gpt_priv *gpt = get_irq_data(virq);
+ int sub_virq;
+ u32 status;
+
+ /* Ask the FPGA for IRQ status. If 'val' is 0, then no irqs
+ * are pending. 'ffs()' is 1 based */
+ status = in_be32(&gpt->regs->status) | 0xF;
+ if (status) {
+ sub_virq = irq_linear_revmap(gpt->irqhost, 0);
+ generic_handle_irq(sub_virq);
+ }
+}
+
+static int mpc52xx_gpt_irq_map(struct irq_host *h, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct mpc52xx_gpt_priv *gpt = h->host_data;
+
+ dev_dbg(gpt->dev, "%s: h=%p, virq=%i\n", __func__, h, virq);
+ set_irq_chip_data(virq, gpt);
+ set_irq_chip_and_handler(virq, &mpc52xx_gpt_irq_chip, handle_edge_irq);
+
+ return 0;
+}
+
+static int mpc52xx_gpt_irq_xlate(struct irq_host *h, struct device_node *ct,
+ u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq,
+ unsigned int *out_flags)
+{
+ struct mpc52xx_gpt_priv *gpt = h->host_data;
+
+ dev_dbg(gpt->dev, "%s: flags=%i\n", __func__, intspec[0]);
+
+ if ((intsize < 1) || (intspec[0] < 1) || (intspec[0] > 3)) {
+ dev_err(gpt->dev, "bad irq specifier in %s\n", ct->full_name);
+ return -ENODEV;
+ }
+
+ *out_hwirq = 0; /* The GPT only has 1 IRQ line */
+ *out_flags = intspec[0];
+
+ WARN_ON(*out_flags == 0);
+
+ return 0;
+}
+
+static struct irq_host_ops mpc52xx_gpt_irq_ops = {
+ .map = mpc52xx_gpt_irq_map,
+ .xlate = mpc52xx_gpt_irq_xlate,
+};
+
+static void
+mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
+{
+ int cascade_virq;
+ unsigned long flags;
+ u32 val;
+
+ /* Only setup cascaded IRQ if device tree claims the GPT is
+ * an interrupt controller */
+ if (!of_find_property(node, "interrupt-controller", NULL))
+ return;
+
+ cascade_virq = irq_of_parse_and_map(node, 0);
+
+ gpt->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR, 1,
+ &mpc52xx_gpt_irq_ops, -1);
+ if (!gpt->irqhost) {
+ dev_err(gpt->dev, "irq_alloc_host() failed\n");
+ return;
+ }
+
+ gpt->irqhost->host_data = gpt;
+
+ set_irq_data(cascade_virq, gpt);
+ set_irq_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
+
+ /* Set to Input Capture mode */
+ spin_lock_irqsave(&gpt->lock, flags);
+ val = in_be32(&gpt->regs->mode) & ~0x7;
+ out_be32(&gpt->regs->mode, val | 0x1); /* IC mode */
+ spin_unlock_irqrestore(&gpt->lock, flags);
+
+ dev_dbg(gpt->dev, "%s() complete. virq=%i\n", __func__, cascade_virq);
+
+ return;
+}
+
+
+/* ---------------------------------------------------------------------
+ * GPIOLIB hooks
+ */
+#if defined(CONFIG_GPIOLIB)
+static inline struct mpc52xx_gpt_priv *gc_to_mpc52xx_gpt(struct gpio_chip *gc)
+{
+ return container_of(to_of_gpio_chip(gc), struct mpc52xx_gpt_priv,of_gc);
+}
+
+static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
+
+ return (in_be32(&gpt->regs->status) >> 8) & 1;
+}
+
+static void
+mpc52xx_gpt_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
+ unsigned long flags;
+ u32 tmp;
+
+ dev_dbg(gpt->dev, "%s: gpio:%d val:%d\n", __func__, gpio, val);
+
+ spin_lock_irqsave(&gpt->lock, flags);
+ tmp = in_be32(&gpt->regs->mode) & ~MPC52xx_GPT_GPIO_MODE_MASK;
+ out_be32(&gpt->regs->mode, tmp | (val ? 0x30 : 0x20));
+ spin_unlock_irqrestore(&gpt->lock, flags);
+}
+
+static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
+ unsigned long flags;
+ u32 tmp;
+
+ dev_dbg(gpt->dev, "%s: gpio:%d\n", __func__, gpio);
+
+ spin_lock_irqsave(&gpt->lock, flags);
+ tmp = in_be32(&gpt->regs->mode) & ~MPC52xx_GPT_GPIO_MODE_MASK;
+ out_be32(&gpt->regs->mode, tmp);
+ spin_unlock_irqrestore(&gpt->lock, flags);
+
+ return 0;
+}
+
+static int
+mpc52xx_gpt_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ mpc52xx_gpt_gpio_set(gc, gpio, val);
+ return 0;
+}
+
+static void
+mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
+{
+ int rc;
+
+ /* Only setup GPIO if the device tree claims the GPT is
+ * a GPIO controller */
+ if (!of_find_property(node, "gpio-controller", NULL))
+ return;
+
+ gpt->of_gc.gc.label = kstrdup(node->full_name, GFP_KERNEL);
+ if (!gpt->of_gc.gc.label) {
+ dev_err(gpt->dev, "out of memory\n");
+ return;
+ }
+
+ gpt->of_gc.gpio_cells = 2;
+ gpt->of_gc.gc.ngpio = 1;
+ gpt->of_gc.gc.direction_input = mpc52xx_gpt_gpio_dir_in;
+ gpt->of_gc.gc.direction_output = mpc52xx_gpt_gpio_dir_out;
+ gpt->of_gc.gc.get = mpc52xx_gpt_gpio_get;
+ gpt->of_gc.gc.set = mpc52xx_gpt_gpio_set;
+ gpt->of_gc.gc.base = -1;
+ gpt->of_gc.xlate = of_gpio_simple_xlate;
+ node->data = &gpt->of_gc;
+ of_node_get(node);
+
+ rc = gpiochip_add(&gpt->of_gc.gc);
+ if (rc)
+ dev_err(gpt->dev, "gpiochip_add() failed; rc=%i\n", rc);
+
+ dev_dbg(gpt->dev, "%s() complete.\n", __func__);
+}
+#else /* defined(CONFIG_GPIOLIB) */
+static void
+mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *, struct device_node *) { }
+#endif /* defined(CONFIG_GPIOLIB) */
+
+/***********************************************************************
+ * SYSFS attributes
+ */
+#if defined(CONFIG_SYSFS)
+static ssize_t mpc52xx_gpt_show_regs(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mpc52xx_gpt_priv *gpt = dev_get_drvdata(dev);
+ int i, len = 0;
+ u32 __iomem *regs = (void __iomem *) gpt->regs;
+
+ for (i = 0; i < 4; i++)
+ len += sprintf(buf + len, "%.8x ", in_be32(regs + i));
+ len += sprintf(buf + len, "\n");
+
+ return len;
+}
+
+static struct device_attribute mpc52xx_gpt_attrib[] = {
+ __ATTR(regs, S_IRUGO | S_IWUSR, mpc52xx_gpt_show_regs, NULL),
+};
+
+static void mpc52xx_gpt_create_attribs(struct mpc52xx_gpt_priv *gpt)
+{
+ int i, err = 0;
+
+ for (i = 0; i < ARRAY_SIZE(mpc52xx_gpt_attrib); i++)
+ err |= device_create_file(gpt->dev, &mpc52xx_gpt_attrib[i]);
+
+ if (err)
+ dev_err(gpt->dev, "device_create_file() failed\n");
+}
+
+#else /* defined(CONFIG_SYSFS) */
+static void mpc52xx_gpt_create_attribs(struct mpc52xx_gpt_priv *) { return 0; }
+#endif /* defined(CONFIG_SYSFS) */
+
+/* ---------------------------------------------------------------------
+ * of_platform bus binding code
+ */
+static int __devinit mpc52xx_gpt_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
+{
+ struct mpc52xx_gpt_priv *gpt;
+ u32 val;
+
+ gpt = kzalloc(sizeof *gpt, GFP_KERNEL);
+ if (!gpt)
+ return -ENOMEM;
+
+ spin_lock_init(&gpt->lock);
+ gpt->dev = &ofdev->dev;
+ gpt->regs = of_iomap(ofdev->node, 0);
+ if (!gpt->regs) {
+ kfree(gpt);
+ return -ENOMEM;
+ }
+
+ /* Setup external pin in GPIO mode */
+ val = in_be32(&gpt->regs->mode) & ~0x7;
+ out_be32(&gpt->regs->mode, val | 0x4);
+
+ dev_set_drvdata(&ofdev->dev, gpt);
+
+ mpc52xx_gpt_create_attribs(gpt);
+ mpc52xx_gpt_gpio_setup(gpt, ofdev->node);
+ mpc52xx_gpt_irq_setup(gpt, ofdev->node);
+
+ return 0;
+}
+
+static int mpc52xx_gpt_remove(struct of_device *ofdev)
+{
+ return -EBUSY;
+}
+
+static const struct of_device_id mpc52xx_gpt_match[] = {
+ { .compatible = "fsl,mpc5200-gpt", },
+
+ /* Depreciated compatible values; don't use for new dts files */
+ { .compatible = "fsl,mpc5200-gpt-gpio", },
+ { .compatible = "mpc5200-gpt", },
+ {}
+};
+
+static struct of_platform_driver mpc52xx_gpt_driver = {
+ .name = "mpc52xx-gpt",
+ .match_table = mpc52xx_gpt_match,
+ .probe = mpc52xx_gpt_probe,
+ .remove = mpc52xx_gpt_remove,
+};
+
+static int __init mpc52xx_gpt_init(void)
+{
+ if (of_register_platform_driver(&mpc52xx_gpt_driver))
+ pr_err("error registering MPC52xx GPT driver\n");
+
+ return 0;
+}
+
+/* Make sure GPIOs and IRQs get set up before anyone tries to use them */
+subsys_initcall(mpc52xx_gpt_init);
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