RE: [PATCH 1/1] drivers/gpio: Altera soft IP GPIO driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

Are the codes good for upstream?

Thanks.

-----Original Message-----
From: Tien Hock Loh
Sent: Tuesday, March 12, 2013 1:38 PM
To: Linus Walleij; Rob Landley
Cc: linux-doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Tien Hock Loh
Subject: [PATCH 1/1] drivers/gpio: Altera soft IP GPIO driver

From: Tien Hock Loh <thloh@xxxxxxxxxx>

Adds a new driver for Altera soft GPIO IP. The driver is able to do read/write and allows GPIO to be a interrupt controller.

Tested on Altera GHRD on interrupt handling and IO.

Signed-off-by: Tien Hock Loh <thloh@xxxxxxxxxx>
---
 .../devicetree/bindings/gpio/gpio-altera.txt       |  37 +++
 drivers/gpio/Kconfig                               |   7 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-altera.c                         | 363 +++++++++++++++++++++
 4 files changed, 408 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-altera.txt
 create mode 100644 drivers/gpio/gpio-altera.c

diff --git a/Documentation/devicetree/bindings/gpio/gpio-altera.txt b/Documentation/devicetree/bindings/gpio/gpio-altera.txt
new file mode 100644
index 0000000..3bdb8b6
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-altera.txt
@@ -0,0 +1,37 @@
+Altera GPIO controller bindings
+
+Required properties:
+- compatible:
+  - "altr,pio-1.0"
+- reg: Physical base address and length of the controller's registers.
+- #gpio-cells : Should be two.
+  - first cell is the pin number
+  - second cell is used to specify optional parameters (unused)
+- gpio-controller : Marks the device node as a GPIO controller.
+- #interrupt-cells : Should be 1.
+- interrupts: Specify the interrupt.
+- interrupt-controller: Mark the device node as an interrupt controller
+  The first cell is the GPIO number.
+
+Altera GPIO specific properties:
+- width: Width of the GPIO bank, range from 1-32
+- level_trigger: Specifies whether the GPIO interrupt is level trigger.
+  This field is required if the Altera GPIO controller used has IRQ enabled.
+
+Note: If the Altera GPIO is set to be built as a module, peripherals
+that uses Altera GPIO as interrupt-parent should be a module so that
+the peripheral doesn't get initialized before Altera GPIO is initialized.
+
+Example:
+
+gpio_altr: gpio_altr {
+    compatible = "altr,pio-1.0";
+    reg = <0xff200000 0x10>;
+    interrupts = <0 45 4>;
+    width = <32>;
+    level_trigger = <0>;
+    #gpio-cells = <2>;
+    gpio-controller;
+    #interrupt-cells = <1>;
+    interrupt-controller;
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 93aaadf..953e9f2 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -119,6 +119,13 @@ config GPIO_GENERIC_PLATFORM
        help
          Say yes here to support basic platform_device memory-mapped GPIO controllers.

+config GPIO_ALTERA
+       tristate "Altera GPIO"
+       select IRQ_DOMAIN
+       depends on OF_GPIO
+       help
+         Say yes here to support the Altera PIO device.
+
 config GPIO_IT8761E
        tristate "IT8761E GPIO support"
        depends on X86  # unconditional access to IO space.
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 22e07bc..c57449c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_GPIO_74X164)     += gpio-74x164.o
 obj-$(CONFIG_GPIO_ADNP)                += gpio-adnp.o
 obj-$(CONFIG_GPIO_ADP5520)     += gpio-adp5520.o
 obj-$(CONFIG_GPIO_ADP5588)     += gpio-adp5588.o
+obj-$(CONFIG_GPIO_ALTERA)      += gpio-altera.o
 obj-$(CONFIG_GPIO_AMD8111)     += gpio-amd8111.o
 obj-$(CONFIG_GPIO_ARIZONA)     += gpio-arizona.o
 obj-$(CONFIG_GPIO_BT8XX)       += gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-altera.c b/drivers/gpio/gpio-altera.c new file mode 100644 index 0000000..b832a3a
--- /dev/null
+++ b/drivers/gpio/gpio-altera.c
@@ -0,0 +1,363 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Based on gpio-mpc8xxx.c
+ *
+ * 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ *
+ * 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, see <http://www.gnu.org/licenses/>
+*/
+
+#include <linux/gpio.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/interrupt.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+
+#define ALTERA_GPIO_DATA               0x0
+#define ALTERA_GPIO_DIR                        0x4
+#define ALTERA_GPIO_IRQ_MASK           0x8
+#define ALTERA_GPIO_EDGE_CAP           0xc
+#define ALTERA_GPIO_OUTSET             0x10
+#define ALTERA_GPIO_OUTCLEAR           0x14
+
+struct altera_gpio_chip {
+       struct of_mm_gpio_chip mmchip;
+       struct irq_domain *irq; /* GPIO controller IRQ number */
+       spinlock_t gpio_lock;   /* Lock used for synchronization */
+       int level_trigger;
+       int hwirq;
+};
+
+static void altera_gpio_irq_unmask(struct irq_data *d) {
+       struct altera_gpio_chip *altera_gc = irq_data_get_irq_chip_data(d);
+       struct of_mm_gpio_chip *mm_gc = &altera_gc->mmchip;
+       unsigned long flags;
+       unsigned int intmask;
+
+       spin_lock_irqsave(&altera_gc->gpio_lock, flags);
+       intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+       /* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
+       intmask |= (1 << irqd_to_hwirq(d));
+       writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+       spin_unlock_irqrestore(&altera_gc->gpio_lock, flags); }
+
+static void altera_gpio_irq_mask(struct irq_data *d) {
+       struct altera_gpio_chip *altera_gc = irq_data_get_irq_chip_data(d);
+       struct of_mm_gpio_chip *mm_gc = &altera_gc->mmchip;
+       unsigned long flags;
+       unsigned int intmask;
+
+       spin_lock_irqsave(&altera_gc->gpio_lock, flags);
+       intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+       /* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
+       intmask &= ~(1 << irqd_to_hwirq(d));
+       writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+       spin_unlock_irqrestore(&altera_gc->gpio_lock, flags); }
+
+static int altera_gpio_irq_set_type(struct irq_data *d,
+                               unsigned int type)
+{
+       if (type == IRQ_TYPE_NONE)
+               return 0;
+       return -EINVAL;
+}
+
+static struct irq_chip altera_irq_chip = {
+       .name           = "altera-gpio",
+       .irq_mask       = altera_gpio_irq_mask,
+       .irq_unmask     = altera_gpio_irq_unmask,
+       .irq_set_type   = altera_gpio_irq_set_type,
+};
+
+static int altera_gpio_get(struct gpio_chip *gc, unsigned offset) {
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+
+       return (readl(mm_gc->regs + ALTERA_GPIO_DATA) >> offset) & 1; }
+
+static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int
+value) {
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+       struct altera_gpio_chip *chip = container_of(mm_gc,
+                               struct altera_gpio_chip, mmchip);
+       unsigned long flags;
+       unsigned int data_reg;
+
+       spin_lock_irqsave(&chip->gpio_lock, flags);
+       data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
+       data_reg = (data_reg & ~(1 << offset)) | (value << offset);
+       writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
+       spin_unlock_irqrestore(&chip->gpio_lock, flags); }
+
+static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned
+offset) {
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+       struct altera_gpio_chip *chip = container_of(mm_gc,
+                               struct altera_gpio_chip, mmchip);
+       unsigned long flags;
+       unsigned int gpio_ddr;
+
+       spin_lock_irqsave(&chip->gpio_lock, flags);
+       /* Set pin as input, assumes software controlled IP */
+       gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
+       gpio_ddr &= ~(1 << offset);
+       writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
+       spin_unlock_irqrestore(&chip->gpio_lock, flags);
+
+       return 0;
+}
+
+static int altera_gpio_direction_output(struct gpio_chip *gc,
+               unsigned offset, int value)
+{
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+       struct altera_gpio_chip *chip = container_of(mm_gc,
+                               struct altera_gpio_chip, mmchip);
+       unsigned long flags;
+       unsigned int data_reg, gpio_ddr;
+
+       spin_lock_irqsave(&chip->gpio_lock, flags);
+       /* Sets the GPIO value */
+       data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
+       data_reg = (data_reg & ~(1 << offset)) | (value << offset);
+        writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
+
+       /* Set pin as output, assumes software controlled IP */
+       gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
+       gpio_ddr |= (1 << offset);
+       writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
+       spin_unlock_irqrestore(&chip->gpio_lock, flags);
+
+       return 0;
+}
+
+static int altera_gpio_to_irq(struct gpio_chip *gc, unsigned offset) {
+       struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+       struct altera_gpio_chip *altera_gc = container_of(mm_gc,
+                               struct altera_gpio_chip, mmchip);
+
+       if (altera_gc->irq == 0)
+               return -ENXIO;
+       if ((altera_gc->irq && offset) < altera_gc->mmchip.gc.ngpio)
+               return irq_create_mapping(altera_gc->irq, offset);
+       else
+               return -ENXIO;
+}
+
+static void altera_gpio_irq_handler(unsigned int irq, struct irq_desc
+*desc) {
+       struct altera_gpio_chip *altera_gc = irq_desc_get_handler_data(desc);
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       struct of_mm_gpio_chip *mm_gc = &altera_gc->mmchip;
+       unsigned long status;
+
+       int base;
+       chip->irq_mask(&desc->irq_data);
+
+       if (altera_gc->level_trigger)
+               status = readl(mm_gc->regs + ALTERA_GPIO_DATA);
+       else {
+               status = readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
+               writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
+       }
+
+       status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+
+       for (base = 0; base < mm_gc->gc.ngpio; base++) {
+               if ((1 << base) & status) {
+                       generic_handle_irq(
+                               irq_linear_revmap(altera_gc->irq, base));
+               }
+       }
+       chip->irq_eoi(irq_desc_get_irq_data(desc));
+       chip->irq_unmask(&desc->irq_data);
+}
+
+static int altera_gpio_irq_map(struct irq_domain *h, unsigned int virq,
+                               irq_hw_number_t hw_irq_num)
+{
+       irq_set_chip_data(virq, h->host_data);
+       irq_set_chip_and_handler(virq, &altera_irq_chip, handle_level_irq);
+       irq_set_irq_type(virq, IRQ_TYPE_NONE);
+
+       return 0;
+}
+
+static struct irq_domain_ops altera_gpio_irq_ops = {
+       .map    = altera_gpio_irq_map,
+       .xlate = irq_domain_xlate_twocell,
+};
+
+int altera_gpio_probe(struct platform_device *pdev) {
+       struct device_node *node = pdev->dev.of_node;
+       int id, reg, ret;
+       struct altera_gpio_chip *altera_gc = devm_kzalloc(&pdev->dev,
+                               sizeof(*altera_gc), GFP_KERNEL);
+       if (altera_gc == NULL) {
+               ret = -ENOMEM;
+               pr_err("%s: registration failed with status %d\n",
+                       node->full_name, ret);
+               return ret;
+       }
+       altera_gc->irq = 0;
+
+       spin_lock_init(&altera_gc->gpio_lock);
+
+       id = pdev->id;
+
+       if (of_property_read_u32(node, "width", &reg))
+               /*By default assume full GPIO controller*/
+               altera_gc->mmchip.gc.ngpio = 32;
+       else
+               altera_gc->mmchip.gc.ngpio = reg;
+
+       if (altera_gc->mmchip.gc.ngpio > 32) {
+               pr_warn("%s: ngpio is greater than 32, defaulting to 32\n",
+                       node->full_name);
+               altera_gc->mmchip.gc.ngpio = 32;
+       }
+
+       altera_gc->mmchip.gc.direction_input    = altera_gpio_direction_input;
+       altera_gc->mmchip.gc.direction_output   = altera_gpio_direction_output;
+       altera_gc->mmchip.gc.get                = altera_gpio_get;
+       altera_gc->mmchip.gc.set                = altera_gpio_set;
+       altera_gc->mmchip.gc.to_irq             = altera_gpio_to_irq;
+       altera_gc->mmchip.gc.owner              = THIS_MODULE;
+
+       ret = of_mm_gpiochip_add(node, &altera_gc->mmchip);
+       if (ret)
+               goto err;
+
+       platform_set_drvdata(pdev, altera_gc);
+
+       if (of_get_property(node, "interrupts", &reg) == NULL)
+               goto skip_irq;
+       altera_gc->hwirq = irq_of_parse_and_map(node, 0);
+
+       if (altera_gc->hwirq == NO_IRQ)
+               goto skip_irq;
+
+       altera_gc->irq = irq_domain_add_linear(node, altera_gc->mmchip.gc.ngpio,
+                               &altera_gpio_irq_ops, altera_gc);
+
+       if (!altera_gc->irq) {
+               ret = -ENODEV;
+               goto dispose_irq;
+       }
+
+       if (of_property_read_u32(node, "level_trigger", &reg)) {
+               ret = -EINVAL;
+               pr_err("%s: level_trigger value not set in device tree\n",
+                       node->full_name);
+               goto teardown;
+       }
+       altera_gc->level_trigger = reg;
+
+       irq_set_handler_data(altera_gc->hwirq, altera_gc);
+       irq_set_chained_handler(altera_gc->hwirq, altera_gpio_irq_handler);
+
+       return 0;
+
+teardown:
+       irq_domain_remove(altera_gc->irq);
+dispose_irq:
+       irq_dispose_mapping(altera_gc->hwirq);
+       WARN_ON(gpiochip_remove(&altera_gc->mmchip.gc) < 0);
+
+err:
+       pr_err("%s: registration failed with status %d\n",
+               node->full_name, ret);
+       devm_kfree(&pdev->dev, altera_gc);
+
+       return ret;
+skip_irq:
+       return 0;
+}
+
+static int altera_gpio_remove(struct platform_device *pdev) {
+       unsigned int irq, i;
+       int status;
+       struct altera_gpio_chip *altera_gc = platform_get_drvdata(pdev);
+
+       status = gpiochip_remove(&altera_gc->mmchip.gc);
+
+       if (status < 0)
+               return status;
+
+       if (altera_gc->irq) {
+               irq_dispose_mapping(altera_gc->hwirq);
+
+               for (i = 0; i < altera_gc->mmchip.gc.ngpio; i++) {
+                       irq = irq_find_mapping(altera_gc->irq, i);
+                       if (irq > 0)
+                               irq_dispose_mapping(irq);
+               }
+
+               irq_domain_remove(altera_gc->irq);
+       }
+
+       irq_set_handler_data(altera_gc->hwirq, NULL);
+       irq_set_chained_handler(altera_gc->hwirq, NULL);
+       devm_kfree(&pdev->dev, altera_gc);
+       return -EIO;
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id altera_gpio_of_match[] = {
+       { .compatible = "altr,pio-1.0", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, altera_gpio_of_match); #else #define
+altera_gpio_of_match NULL #endif
+
+static struct platform_driver altera_gpio_driver = {
+       .driver = {
+               .name   = "altera_gpio",
+               .owner  = THIS_MODULE,
+               .of_match_table = of_match_ptr(altera_gpio_of_match),
+       },
+       .probe          = altera_gpio_probe,
+       .remove         = altera_gpio_remove,
+};
+
+static int __init altera_gpio_init(void) {
+       return platform_driver_register(&altera_gpio_driver);
+}
+subsys_initcall(altera_gpio_init);
+
+static void __exit altera_gpio_exit(void) {
+       platform_driver_unregister(&altera_gpio_driver);
+}
+module_exit(altera_gpio_exit);
+
+MODULE_DESCRIPTION("Altera GPIO driver"); MODULE_LICENSE("GPL");
--
1.7.11.GIT


Confidentiality Notice.
This message may contain information that is confidential or otherwise protected from disclosure. If you are not the intended recipient, you are hereby notified that any use, disclosure, dissemination, distribution,  or copying  of this message, or any attachments, is strictly prohibited.  If you have received this message in error, please advise the sender by reply e-mail, and delete the message and any attachments.  Thank you.

--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux