[PATCH] gpio: Emma Mobile GPIO driver

Magnus Damm
2012-05-11T09:40:12Z

From: Magnus Damm <damm@opensource.se>

This patch adds a GPIO driver for the Emma Mobile line
of SoCs. The driver is designed to be reusable between
multiple SoCs that share the same basic building block,
but so far it has only been used on Emma Mobile EV2.

Each driver instance handles 32 GPIOs with individually
maskable IRQs. The driver operates on two I/O memory
ranges and the 32 GPIOs are hooked up to two interrupts.

In the case of Emma Mobile EV2 this GPIO building block
is used as main external interrupt controller hooking up
159 GPIOS as 159 interrupts via 5 driver instances and
10 interrupts to the GIC and the Cortex-A9 Dual.

This version of the driver gets all configuration via
struct resource and platform data, but DT bindings are
currently in development and such support will be sent
as a individual feature patch in the near future.

Signed-off-by: Magnus Damm <damm@opensource.se>
---

Built on top of linux-next 20120511. There are no known
merge or runtime dependencies on queued up patches.

drivers/gpio/Kconfig | 6
drivers/gpio/Makefile | 1
drivers/gpio/gpio-em.c | 385 +++++++++++++++++++++++++++++++++
include/linux/platform_data/gpio-em.h | 10
4 files changed, 402 insertions(+)

--- 0001/drivers/gpio/Kconfig
+++ work/drivers/gpio/Kconfig 2012-05-11 18:04:53.000000000 +0900
@@ -95,6 +95,12 @@ config GPIO_IT8761E
help
Say yes here to support GPIO functionality of IT8761E super I/O chip.

+config GPIO_EM
+ tristate "Emma Mobile GPIO"
+ depends on ARM
+ help
+ Say yes here to support GPIO on Renesas Emma Mobile SoCs.
+
config GPIO_EP93XX
def_bool y
depends on ARCH_EP93XX
--- 0001/drivers/gpio/Makefile
+++ work/drivers/gpio/Makefile 2012-05-11 18:04:53.000000000 +0900
@@ -16,6 +16,7 @@ obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o
obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
obj-$(CONFIG_ARCH_DAVINCI) += gpio-davinci.o
+obj-$(CONFIG_GPIO_EM) += gpio-em.o
obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o
obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
--- /dev/null
+++ work/drivers/gpio/gpio-em.c 2012-05-11 18:06:47.000000000 +0900
@@ -0,0 +1,385 @@
+/*
+ * Emma Mobile GPIO Support - GIO
+ *
+ * Copyright (C) 2012 Magnus Damm
+ *
+ * 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
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_data/gpio-em.h>
+
+struct em_gio_priv {
+ void __iomem *base0;
+ void __iomem *base1;
+ unsigned int irq_base;
+ spinlock_t sense_lock;
+ struct gpio_chip gpio_chip;
+ struct irq_chip irq_chip;
+};
+
+#define GIO_E1 0x00
+#define GIO_E0 0x04
+#define GIO_EM 0x04
+#define GIO_OL 0x08
+#define GIO_OH 0x0c
+#define GIO_I 0x10
+#define GIO_IIA 0x14
+#define GIO_IEN 0x18
+#define GIO_IDS 0x1c
+#define GIO_IIM 0x1c
+#define GIO_RAW 0x20
+#define GIO_MST 0x24
+#define GIO_IIR 0x28
+
+#define GIO_IDT0 0x40
+#define GIO_IDT1 0x44
+#define GIO_IDT2 0x48
+#define GIO_IDT3 0x4c
+#define GIO_RAWBL 0x50
+#define GIO_RAWBH 0x54
+#define GIO_IRBL 0x58
+#define GIO_IRBH 0x5c
+
+#define GIO_IDT(n) GIO_IDT0 + ((n) * 4)
+
+static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
+{
+ if (offs < GIO_IDT0)
+ return ioread32(p->base0 + offs);
+ else
+ return ioread32(p->base1 + (offs - GIO_IDT0));
+}
+
+static inline void em_gio_write(struct em_gio_priv *p, int offs,
+ unsigned long value)
+{
+ if (offs < GIO_IDT0)
+ iowrite32(value, p->base0 + offs);
+ else
+ iowrite32(value, p->base1 + (offs - GIO_IDT0));
+}
+
+static struct em_gio_priv *irq_to_priv(unsigned int irq)
+{
+ struct irq_chip *chip = irq_get_chip(irq);
+ return container_of(chip, struct em_gio_priv, irq_chip);
+}
+
+static void em_gio_irq_disable(struct irq_data *data)
+{
+ struct em_gio_priv *p = irq_to_priv(data->irq);
+ int offset = data->irq - p->irq_base;
+
+ em_gio_write(p, GIO_IDS, 1 << offset);
+}
+
+static void em_gio_irq_enable(struct irq_data *data)
+{
+ struct em_gio_priv *p = irq_to_priv(data->irq);
+ int offset = data->irq - p->irq_base;
+
+ em_gio_write(p, GIO_IEN, 1 << offset);
+}
+
+#define GIO_ASYNC(x) (x + 8)
+
+static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
+ [IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
+ [IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
+ [IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
+ [IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
+ [IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
+};
+
+static int em_gio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
+ struct em_gio_priv *p = irq_to_priv(data->irq);
+ unsigned int reg, offset, shift;
+ unsigned long flags;
+ unsigned long tmp;
+
+ if (!value)
+ return -EINVAL;
+
+ offset = data->irq - p->irq_base;
+
+ pr_debug("gio: sense irq = %d, irq = %d, mode = %d, sw base = %d\n",
+ offset, data->irq, value, p->irq_base);
+
+ /* 8 x 4 bit fields in 4 IDT registers */
+ reg = GIO_IDT(offset >> 3);
+ shift = (offset & 0x07) << 4;
+
+ spin_lock_irqsave(&p->sense_lock, flags);
+
+ /* disable the interrupt in IIA */
+ tmp = em_gio_read(p, GIO_IIA);
+ tmp &= ~(1 << offset);
+ em_gio_write(p, GIO_IIA, tmp);
+
+ /* change the sense setting in IDT */
+ tmp = em_gio_read(p, reg);
+ tmp &= ~(0xf << shift);
+ tmp |= value << shift;
+ em_gio_write(p, reg, tmp);
+
+ /* clear pending interrupts */
+ em_gio_write(p, GIO_IIR, 1 << offset);
+
+ /* enable the interrupt in IIA */
+ tmp = em_gio_read(p, GIO_IIA);
+ tmp |= 1 << offset;
+ em_gio_write(p, GIO_IIA, tmp);
+
+ spin_unlock_irqrestore(&p->sense_lock, flags);
+
+ return 0;
+}
+
+static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
+{
+ struct em_gio_priv *p = dev_id;
+ unsigned long tmp, status;
+ unsigned int offset;
+
+ status = tmp = em_gio_read(p, GIO_MST);
+ if (!status)
+ return IRQ_NONE;
+
+ while (status) {
+ offset = __ffs(status);
+ generic_handle_irq(p->irq_base + offset);
+ status &= ~(1 << offset);
+ }
+
+ em_gio_write(p, GIO_IIR, tmp);
+
+ return IRQ_HANDLED;
+}
+
+static struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
+{
+ return container_of(chip, struct em_gio_priv, gpio_chip);
+}
+
+static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ em_gio_write(gpio_to_priv(chip), GIO_E0, 1 << offset);
+ return 0;
+}
+
+static int em_gio_get(struct gpio_chip *chip, unsigned offset)
+{
+ return (int)(em_gio_read(gpio_to_priv(chip), GIO_I) & (1 << offset));
+}
+
+static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
+ unsigned shift, int value)
+{
+ /* upper 16 bits contains mask and lower 16 actual value */
+ em_gio_write(gpio_to_priv(chip), reg,
+ (1 << (shift + 16)) | (value << shift));
+}
+
+static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ /* output is split into two registers */
+ if (offset < 16)
+ __em_gio_set(chip, GIO_OL, offset, value);
+ else
+ __em_gio_set(chip, GIO_OH, offset - 16, value);
+}
+
+static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ /* write GPIO value to output before selecting output mode of pin */
+ em_gio_set(chip, offset, value);
+ em_gio_write(gpio_to_priv(chip), GIO_E1, 1 << offset);
+ return 0;
+}
+
+static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ return gpio_to_priv(chip)->irq_base + offset;
+}
+
+static int __devinit em_gio_probe(struct platform_device *pdev)
+{
+ struct gpio_em_config *pdata = pdev->dev.platform_data;
+ struct em_gio_priv *p;
+ struct resource *io[2], *irq[2];
+ struct gpio_chip *gpio_chip;
+ struct irq_chip *irq_chip;
+ const char *name = dev_name(&pdev->dev);
+ int k, ret;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p) {
+ dev_err(&pdev->dev, "failed to allocate driver data\n");
+ ret = -ENOMEM;
+ goto err0;
+ }
+
+ gpio_chip = &p->gpio_chip;
+ irq_chip = &p->irq_chip;
+ platform_set_drvdata(pdev, p);
+ spin_lock_init(&p->sense_lock);
+
+ io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+ if (!io[0] || !io[1] || !irq[0] || !irq[1] || !pdata) {
+ dev_err(&pdev->dev, "missing IRQ, IOMEM or configuration\n");
+ ret = -EINVAL;
+ goto err1;
+ }
+
+ p->base0 = ioremap_nocache(io[0]->start, resource_size(io[0]));
+ if (!p->base0) {
+ dev_err(&pdev->dev, "failed to remap low I/O memory\n");
+ ret = -ENXIO;
+ goto err1;
+ }
+
+ p->base1 = ioremap_nocache(io[1]->start, resource_size(io[1]));
+ if (!p->base1) {
+ dev_err(&pdev->dev, "failed to remap high I/O memory\n");
+ ret = -ENXIO;
+ goto err2;
+ }
+
+ p->irq_base = irq_alloc_descs(pdata->irq_base, 0,
+ pdata->number_of_pins, numa_node_id());
+ if (IS_ERR_VALUE(p->irq_base)) {
+ dev_err(&pdev->dev, "cannot get irq_desc\n");
+ ret = -ENXIO;
+ goto err3;
+ }
+
+ pr_debug("gio: hw base = %d, nr = %d, sw base = %d\n",
+ pdata->gpio_base, pdata->number_of_pins, p->irq_base);
+
+ irq_chip->name = name;
+ irq_chip->irq_mask = em_gio_irq_disable;
+ irq_chip->irq_unmask = em_gio_irq_enable;
+ irq_chip->irq_enable = em_gio_irq_enable;
+ irq_chip->irq_disable = em_gio_irq_disable;
+ irq_chip->irq_set_type = em_gio_irq_set_type;
+ irq_chip->flags = IRQCHIP_SKIP_SET_WAKE;
+
+ for (k = p->irq_base; k < (p->irq_base + pdata->number_of_pins); k++) {
+ irq_set_chip_and_handler_name(k, irq_chip, handle_level_irq,
+ "level");
+ set_irq_flags(k, IRQF_VALID); /* kill me now */
+ }
+
+ if (request_irq(irq[0]->start, em_gio_irq_handler, 0, name, p)) {
+ dev_err(&pdev->dev, "failed to request low IRQ\n");
+ ret = -ENOENT;
+ goto err4;
+ }
+
+ if (request_irq(irq[1]->start, em_gio_irq_handler, 0, name, p)) {
+ dev_err(&pdev->dev, "failed to request high IRQ\n");
+ ret = -ENOENT;
+ goto err5;
+ }
+
+ gpio_chip->direction_input = em_gio_direction_input;
+ gpio_chip->get = em_gio_get;
+ gpio_chip->direction_output = em_gio_direction_output;
+ gpio_chip->set = em_gio_set;
+
+ gpio_chip->to_irq = em_gio_to_irq;
+
+ gpio_chip->label = name;
+ gpio_chip->owner = THIS_MODULE;
+
+ gpio_chip->base = pdata->gpio_base;
+ gpio_chip->ngpio = pdata->number_of_pins;
+
+ ret = gpiochip_add(gpio_chip);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to add GPIO cntroller\n");
+ goto err6;
+ }
+ return 0;
+
+err6:
+ free_irq(irq[1]->start, pdev);
+err5:
+ free_irq(irq[0]->start, pdev);
+err4:
+ irq_free_descs(p->irq_base, pdata->number_of_pins);
+err3:
+ iounmap(p->base1);
+err2:
+ iounmap(p->base0);
+err1:
+ kfree(p);
+err0:
+ return ret;
+}
+
+static int __devexit em_gio_remove(struct platform_device *pdev)
+{
+ struct gpio_em_config *pdata = pdev->dev.platform_data;
+ struct em_gio_priv *p = platform_get_drvdata(pdev);
+ struct resource *irq[2];
+ int ret;
+
+ ret = gpiochip_remove(&p->gpio_chip);
+ if (ret)
+ return ret;
+
+ irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+ free_irq(irq[1]->start, pdev);
+ free_irq(irq[0]->start, pdev);
+ irq_free_descs(p->irq_base, pdata->number_of_pins);
+ iounmap(p->base1);
+ iounmap(p->base0);
+ kfree(p);
+ return 0;
+}
+
+static struct platform_driver em_gio_device_driver = {
+ .probe = em_gio_probe,
+ .remove = __devexit_p(em_gio_remove),
+ .driver = {
+ .name = "em_gio",
+ }
+};
+
+module_platform_driver(em_gio_device_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
+MODULE_LICENSE("GPL v2");
--- /dev/null
+++ work/include/linux/platform_data/gpio-em.h 2012-05-11 18:04:54.000000000 +0900
@@ -0,0 +1,10 @@
+#ifndef __GPIO_EM_H__
+#define __GPIO_EM_H__
+
+struct gpio_em_config {
+ unsigned int gpio_base;
+ unsigned int irq_base;
+ unsigned int number_of_pins;
+};
+
+#endif /* __GPIO_EM_H__ */