[PATCH v2 2/6] GPIO: xilinx: Add support for dual channel
Michal Simek
michal.simek at xilinx.com
Mon Jun 3 22:31:17 EST 2013
Supporting the second channel in the driver.
Offset is 0x8 and both channnels share the same
IRQ.
Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---
Changes in v2:
- Use kernel doc format - suggested by Linus Walleij
- Do not use __raw_readl/__raw_writel IO in this patch
- Use of_property_read_u32 helper function
- Use BIT()
- Change patch subject
drivers/gpio/gpio-xilinx.c | 103 +++++++++++++++++++++++++++++++++++++++------
1 file changed, 91 insertions(+), 12 deletions(-)
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 2aad534..626eaa8 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -1,7 +1,7 @@
/*
- * Xilinx gpio driver
+ * Xilinx gpio driver for xps/axi_gpio IP.
*
- * Copyright 2008 Xilinx, Inc.
+ * Copyright 2008 - 2013 Xilinx, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
@@ -12,6 +12,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/module.h>
@@ -26,11 +27,26 @@
#define XGPIO_DATA_OFFSET (0x0) /* Data register */
#define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */
+#define XGPIO_CHANNEL_OFFSET 0x8
+
+/* Read/Write access to the GPIO registers */
+#define xgpio_readreg(offset) in_be32(offset)
+#define xgpio_writereg(offset, val) out_be32(offset, val)
+
+/**
+ * struct xgpio_instance - Stores information about GPIO device
+ * struct of_mm_gpio_chip mmchip: OF GPIO chip for memory mapped banks
+ * gpio_state: GPIO state shadow register
+ * gpio_dir: GPIO direction shadow register
+ * offset: GPIO channel offset
+ * gpio_lock: Lock used for synchronization
+ */
struct xgpio_instance {
struct of_mm_gpio_chip mmchip;
- u32 gpio_state; /* GPIO state shadow register */
- u32 gpio_dir; /* GPIO direction shadow register */
- spinlock_t gpio_lock; /* Lock used for synchronization */
+ u32 gpio_state;
+ u32 gpio_dir;
+ u32 offset;
+ spinlock_t gpio_lock;
};
/**
@@ -44,8 +60,12 @@ struct xgpio_instance {
static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
{
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct xgpio_instance *chip =
+ container_of(mm_gc, struct xgpio_instance, mmchip);
- return (in_be32(mm_gc->regs + XGPIO_DATA_OFFSET) >> gpio) & 1;
+ void __iomem *regs = mm_gc->regs + chip->offset;
+
+ return !!(xgpio_readreg(regs + XGPIO_DATA_OFFSET) & BIT(gpio));
}
/**
@@ -63,6 +83,7 @@ static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
struct xgpio_instance *chip =
container_of(mm_gc, struct xgpio_instance, mmchip);
+ void __iomem *regs = mm_gc->regs;
spin_lock_irqsave(&chip->gpio_lock, flags);
@@ -71,7 +92,9 @@ static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
chip->gpio_state |= 1 << gpio;
else
chip->gpio_state &= ~(1 << gpio);
- out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
+
+ xgpio_writereg(regs + chip->offset + XGPIO_DATA_OFFSET,
+ chip->gpio_state);
spin_unlock_irqrestore(&chip->gpio_lock, flags);
}
@@ -91,12 +114,13 @@ static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
struct xgpio_instance *chip =
container_of(mm_gc, struct xgpio_instance, mmchip);
+ void __iomem *regs = mm_gc->regs;
spin_lock_irqsave(&chip->gpio_lock, flags);
/* Set the GPIO bit in shadow register and set direction as input */
chip->gpio_dir |= (1 << gpio);
- out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
+ xgpio_writereg(regs + chip->offset + XGPIO_TRI_OFFSET, chip->gpio_dir);
spin_unlock_irqrestore(&chip->gpio_lock, flags);
@@ -119,6 +143,7 @@ static int xgpio_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 xgpio_instance *chip =
container_of(mm_gc, struct xgpio_instance, mmchip);
+ void __iomem *regs = mm_gc->regs;
spin_lock_irqsave(&chip->gpio_lock, flags);
@@ -127,11 +152,12 @@ static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
chip->gpio_state |= 1 << gpio;
else
chip->gpio_state &= ~(1 << gpio);
- out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
+ xgpio_writereg(regs + chip->offset + XGPIO_DATA_OFFSET,
+ chip->gpio_state);
/* Clear the GPIO bit in shadow register and set direction as output */
chip->gpio_dir &= (~(1 << gpio));
- out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
+ xgpio_writereg(regs + chip->offset + XGPIO_TRI_OFFSET, chip->gpio_dir);
spin_unlock_irqrestore(&chip->gpio_lock, flags);
@@ -147,8 +173,10 @@ static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
struct xgpio_instance *chip =
container_of(mm_gc, struct xgpio_instance, mmchip);
- out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
- out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
+ xgpio_writereg(mm_gc->regs + chip->offset + XGPIO_DATA_OFFSET,
+ chip->gpio_state);
+ xgpio_writereg(mm_gc->regs + chip->offset + XGPIO_TRI_OFFSET,
+ chip->gpio_dir);
}
/**
@@ -202,6 +230,57 @@ static int xgpio_of_probe(struct device_node *np)
np->full_name, status);
return status;
}
+
+ pr_info("XGpio: %s: registered, base is %d\n", np->full_name,
+ chip->mmchip.gc.base);
+
+ tree_info = of_get_property(np, "xlnx,is-dual", NULL);
+ if (tree_info && be32_to_cpup(tree_info)) {
+ chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ /* Add dual channel offset */
+ chip->offset = XGPIO_CHANNEL_OFFSET;
+
+ /* Update GPIO state shadow register with default value */
+ of_property_read_u32(np, "xlnx,dout-default-2",
+ &chip->gpio_state);
+
+ /* By default, all pins are inputs */
+ chip->gpio_dir = 0xFFFFFFFF;
+
+ /* Update GPIO direction shadow register with default value */
+ of_property_read_u32(np, "xlnx,tri-default-2", &chip->gpio_dir);
+
+ /* By default assume full GPIO controller */
+ chip->mmchip.gc.ngpio = 32;
+
+ /* Check device node and parent device node for device width */
+ of_property_read_u32(np, "xlnx,gpio2-width",
+ (u32 *)&chip->mmchip.gc.ngpio);
+
+ spin_lock_init(&chip->gpio_lock);
+
+ chip->mmchip.gc.direction_input = xgpio_dir_in;
+ chip->mmchip.gc.direction_output = xgpio_dir_out;
+ chip->mmchip.gc.get = xgpio_get;
+ chip->mmchip.gc.set = xgpio_set;
+
+ chip->mmchip.save_regs = xgpio_save_regs;
+
+ /* Call the OF gpio helper to setup and register the GPIO dev */
+ status = of_mm_gpiochip_add(np, &chip->mmchip);
+ if (status) {
+ kfree(chip);
+ pr_err("%s: error in probe function with status %d\n",
+ np->full_name, status);
+ return status;
+ }
+ pr_info("XGpio: %s: dual channel registered, base is %d\n",
+ np->full_name, chip->mmchip.gc.base);
+ }
+
return 0;
}
--
1.8.2.3
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