diff options
| -rw-r--r-- | drivers/gpio/gpio-xilinx.c | 103 |
1 files 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; } |