linux-hardened/arch/arm/mach-davinci/gpio.c
David Brownell 474dad54ba davinci: gpio bugfixes
Update the DaVinci GPIO code to work better on non-dm6446 parts,
notably the dm355:

 - Only handle the number of GPIOs the chip actually has.  So
   for example on dm6467, GPIO-42 is the last GPIO, and trying
   to use GPIO-43 now fails cleanly; or GPIO-72 on dm6446.

 - Enable GPIO interrupts on each 16-bit GPIO-irq bank ...
   previously, only the first five were enabled, so GPIO-80
   and above (on dm355) wouldn't trigger IRQs.

 - Use the right IRQ for each GPIO bank.  The wrong values were
   used for dm355 chips, so GPIO IRQs got routed incorrectly.

 - Handle up to four pairs of 16-bit GPIO banks ... previously
   only three were handled, so accessing GPIO-96 and up (e.g. on
   dm355) would oops.

 - Update several comments that were dm6446-specific.

Verified by receiving GPIO-1 (dm9000) and GPIO-5 (msp430) IRQs
on the DM355 EVM.

One thing this doesn't do is handle the way some of the GPIO
numbers on dm6467 are reserved but aren't valid as GPIOs.  Some
bitmap logic could fix that if needed.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2009-04-27 09:49:43 -07:00

328 lines
8.5 KiB
C

/*
* TI DaVinci GPIO Support
*
* Copyright (c) 2006-2007 David Brownell
* Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
*
* 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.
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/bitops.h>
#include <mach/cputype.h>
#include <mach/irqs.h>
#include <mach/hardware.h>
#include <mach/gpio.h>
#include <asm/mach/irq.h>
static DEFINE_SPINLOCK(gpio_lock);
struct davinci_gpio {
struct gpio_chip chip;
struct gpio_controller *__iomem regs;
};
static struct davinci_gpio chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
static unsigned __initdata ngpio;
/* create a non-inlined version */
static struct gpio_controller __iomem * __init gpio2controller(unsigned gpio)
{
return __gpio_to_controller(gpio);
}
/*--------------------------------------------------------------------------*/
/*
* board setup code *MUST* set PINMUX0 and PINMUX1 as
* needed, and enable the GPIO clock.
*/
static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
{
struct davinci_gpio *d = container_of(chip, struct davinci_gpio, chip);
struct gpio_controller *__iomem g = d->regs;
u32 temp;
spin_lock(&gpio_lock);
temp = __raw_readl(&g->dir);
temp |= (1 << offset);
__raw_writel(temp, &g->dir);
spin_unlock(&gpio_lock);
return 0;
}
/*
* Read the pin's value (works even if it's set up as output);
* returns zero/nonzero.
*
* Note that changes are synched to the GPIO clock, so reading values back
* right after you've set them may give old values.
*/
static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct davinci_gpio *d = container_of(chip, struct davinci_gpio, chip);
struct gpio_controller *__iomem g = d->regs;
return (1 << offset) & __raw_readl(&g->in_data);
}
static int
davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
{
struct davinci_gpio *d = container_of(chip, struct davinci_gpio, chip);
struct gpio_controller *__iomem g = d->regs;
u32 temp;
u32 mask = 1 << offset;
spin_lock(&gpio_lock);
temp = __raw_readl(&g->dir);
temp &= ~mask;
__raw_writel(mask, value ? &g->set_data : &g->clr_data);
__raw_writel(temp, &g->dir);
spin_unlock(&gpio_lock);
return 0;
}
/*
* Assuming the pin is muxed as a gpio output, set its output value.
*/
static void
davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct davinci_gpio *d = container_of(chip, struct davinci_gpio, chip);
struct gpio_controller *__iomem g = d->regs;
__raw_writel((1 << offset), value ? &g->set_data : &g->clr_data);
}
static int __init davinci_gpio_setup(void)
{
int i, base;
/* The gpio banks conceptually expose a segmented bitmap,
* and "ngpio" is one more than the largest zero-based
* bit index that's valid.
*/
if (cpu_is_davinci_dm355()) { /* or dm335() */
ngpio = 104;
} else if (cpu_is_davinci_dm644x()) { /* or dm337() */
ngpio = 71;
} else if (cpu_is_davinci_dm646x()) {
/* NOTE: each bank has several "reserved" bits,
* unusable as GPIOs. Only 33 of the GPIO numbers
* are usable, and we're not rejecting the others.
*/
ngpio = 43;
} else {
/* if cpu_is_davinci_dm643x() ngpio = 111 */
pr_err("GPIO setup: how many GPIOs?\n");
return -EINVAL;
}
if (WARN_ON(DAVINCI_N_GPIO < ngpio))
ngpio = DAVINCI_N_GPIO;
for (i = 0, base = 0; base < ngpio; i++, base += 32) {
chips[i].chip.label = "DaVinci";
chips[i].chip.direction_input = davinci_direction_in;
chips[i].chip.get = davinci_gpio_get;
chips[i].chip.direction_output = davinci_direction_out;
chips[i].chip.set = davinci_gpio_set;
chips[i].chip.base = base;
chips[i].chip.ngpio = ngpio - base;
if (chips[i].chip.ngpio > 32)
chips[i].chip.ngpio = 32;
chips[i].regs = gpio2controller(base);
gpiochip_add(&chips[i].chip);
}
return 0;
}
pure_initcall(davinci_gpio_setup);
/*--------------------------------------------------------------------------*/
/*
* We expect irqs will normally be set up as input pins, but they can also be
* used as output pins ... which is convenient for testing.
*
* NOTE: The first few GPIOs also have direct INTC hookups in addition
* to their GPIOBNK0 irq, with a bit less overhead but less flexibility
* on triggering (e.g. no edge options). We don't try to use those.
*
* All those INTC hookups (direct, plus several IRQ banks) can also
* serve as EDMA event triggers.
*/
static void gpio_irq_disable(unsigned irq)
{
struct gpio_controller *__iomem g = get_irq_chip_data(irq);
u32 mask = __gpio_mask(irq_to_gpio(irq));
__raw_writel(mask, &g->clr_falling);
__raw_writel(mask, &g->clr_rising);
}
static void gpio_irq_enable(unsigned irq)
{
struct gpio_controller *__iomem g = get_irq_chip_data(irq);
u32 mask = __gpio_mask(irq_to_gpio(irq));
if (irq_desc[irq].status & IRQ_TYPE_EDGE_FALLING)
__raw_writel(mask, &g->set_falling);
if (irq_desc[irq].status & IRQ_TYPE_EDGE_RISING)
__raw_writel(mask, &g->set_rising);
}
static int gpio_irq_type(unsigned irq, unsigned trigger)
{
struct gpio_controller *__iomem g = get_irq_chip_data(irq);
u32 mask = __gpio_mask(irq_to_gpio(irq));
if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
return -EINVAL;
irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
irq_desc[irq].status |= trigger;
__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
? &g->set_falling : &g->clr_falling);
__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
? &g->set_rising : &g->clr_rising);
return 0;
}
static struct irq_chip gpio_irqchip = {
.name = "GPIO",
.enable = gpio_irq_enable,
.disable = gpio_irq_disable,
.set_type = gpio_irq_type,
};
static void
gpio_irq_handler(unsigned irq, struct irq_desc *desc)
{
struct gpio_controller *__iomem g = get_irq_chip_data(irq);
u32 mask = 0xffff;
/* we only care about one bank */
if (irq & 1)
mask <<= 16;
/* temporarily mask (level sensitive) parent IRQ */
desc->chip->ack(irq);
while (1) {
u32 status;
int n;
int res;
/* ack any irqs */
status = __raw_readl(&g->intstat) & mask;
if (!status)
break;
__raw_writel(status, &g->intstat);
if (irq & 1)
status >>= 16;
/* now demux them to the right lowlevel handler */
n = (int)get_irq_data(irq);
while (status) {
res = ffs(status);
n += res;
generic_handle_irq(n - 1);
status >>= res;
}
}
desc->chip->unmask(irq);
/* now it may re-trigger */
}
/*
* NOTE: for suspend/resume, probably best to make a platform_device with
* suspend_late/resume_resume calls hooking into results of the set_wake()
* calls ... so if no gpios are wakeup events the clock can be disabled,
* with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
* (dm6446) can be set appropriately for GPIOV33 pins.
*/
static int __init davinci_gpio_irq_setup(void)
{
unsigned gpio, irq, bank;
unsigned bank_irq;
struct clk *clk;
u32 binten = 0;
if (cpu_is_davinci_dm355()) { /* or dm335() */
bank_irq = IRQ_DM355_GPIOBNK0;
} else if (cpu_is_davinci_dm644x()) {
bank_irq = IRQ_GPIOBNK0;
} else if (cpu_is_davinci_dm646x()) {
bank_irq = IRQ_DM646X_GPIOBNK0;
} else {
printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
return -EINVAL;
}
clk = clk_get(NULL, "gpio");
if (IS_ERR(clk)) {
printk(KERN_ERR "Error %ld getting gpio clock?\n",
PTR_ERR(clk));
return PTR_ERR(clk);
}
clk_enable(clk);
for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
gpio < ngpio;
bank++, bank_irq++) {
struct gpio_controller *__iomem g = gpio2controller(gpio);
unsigned i;
__raw_writel(~0, &g->clr_falling);
__raw_writel(~0, &g->clr_rising);
/* set up all irqs in this bank */
set_irq_chained_handler(bank_irq, gpio_irq_handler);
set_irq_chip_data(bank_irq, g);
set_irq_data(bank_irq, (void *)irq);
for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
set_irq_chip(irq, &gpio_irqchip);
set_irq_chip_data(irq, g);
set_irq_handler(irq, handle_simple_irq);
set_irq_flags(irq, IRQF_VALID);
}
binten |= BIT(bank);
}
/* BINTEN -- per-bank interrupt enable. genirq would also let these
* bits be set/cleared dynamically.
*/
__raw_writel(binten, (void *__iomem)
IO_ADDRESS(DAVINCI_GPIO_BASE + 0x08));
printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));
return 0;
}
arch_initcall(davinci_gpio_irq_setup);