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sm501: add gpiolib support
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Add support for exporting the GPIOs on the SM501 via gpiolib.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: Arnaud Patard <apatard@mandriva.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ben Dooks authored and Linus Torvalds committed Jul 25, 2008
1 parent 472dba7 commit f61be27
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Showing 3 changed files with 257 additions and 70 deletions.
8 changes: 8 additions & 0 deletions drivers/mfd/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,14 @@ config MFD_SM501
interface. The device may be connected by PCI or local bus with
varying functions enabled.

config MFD_SM501_GPIO
bool "Export GPIO via GPIO layer"
depends on MFD_SM501 && HAVE_GPIO_LIB
---help---
This option uses the gpio library layer to export the 64 GPIO
lines on the SM501. The platform data is used to supply the
base number for the first GPIO line to register.

config MFD_ASIC3
bool "Support for Compaq ASIC3"
depends on GENERIC_HARDIRQS && HAVE_GPIO_LIB && ARM
Expand Down
299 changes: 247 additions & 52 deletions drivers/mfd/sm501.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/gpio.h>

#include <linux/sm501.h>
#include <linux/sm501-regs.h>
Expand All @@ -31,17 +32,37 @@ struct sm501_device {
struct platform_device pdev;
};

struct sm501_gpio;

struct sm501_gpio_chip {
struct gpio_chip gpio;
struct sm501_gpio *ourgpio; /* to get back to parent. */
void __iomem *regbase;
};

struct sm501_gpio {
struct sm501_gpio_chip low;
struct sm501_gpio_chip high;
spinlock_t lock;

unsigned int registered : 1;
void __iomem *regs;
struct resource *regs_res;
};

struct sm501_devdata {
spinlock_t reg_lock;
struct mutex clock_lock;
struct list_head devices;
struct sm501_gpio gpio;

struct device *dev;
struct resource *io_res;
struct resource *mem_res;
struct resource *regs_claim;
struct sm501_platdata *platdata;


unsigned int in_suspend;
unsigned long pm_misc;

Expand All @@ -52,6 +73,7 @@ struct sm501_devdata {
unsigned int rev;
};


#define MHZ (1000 * 1000)

#ifdef DEBUG
Expand Down Expand Up @@ -276,58 +298,6 @@ unsigned long sm501_modify_reg(struct device *dev,

EXPORT_SYMBOL_GPL(sm501_modify_reg);

unsigned long sm501_gpio_get(struct device *dev,
unsigned long gpio)
{
struct sm501_devdata *sm = dev_get_drvdata(dev);
unsigned long result;
unsigned long reg;

reg = (gpio > 32) ? SM501_GPIO_DATA_HIGH : SM501_GPIO_DATA_LOW;
result = readl(sm->regs + reg);

result >>= (gpio & 31);
return result & 1UL;
}

EXPORT_SYMBOL_GPL(sm501_gpio_get);

void sm501_gpio_set(struct device *dev,
unsigned long gpio,
unsigned int to,
unsigned int dir)
{
struct sm501_devdata *sm = dev_get_drvdata(dev);

unsigned long bit = 1 << (gpio & 31);
unsigned long base;
unsigned long save;
unsigned long val;

base = (gpio > 32) ? SM501_GPIO_DATA_HIGH : SM501_GPIO_DATA_LOW;
base += SM501_GPIO;

spin_lock_irqsave(&sm->reg_lock, save);

val = readl(sm->regs + base) & ~bit;
if (to)
val |= bit;
writel(val, sm->regs + base);

val = readl(sm->regs + SM501_GPIO_DDR_LOW) & ~bit;
if (dir)
val |= bit;

writel(val, sm->regs + SM501_GPIO_DDR_LOW);
sm501_sync_regs(sm);

spin_unlock_irqrestore(&sm->reg_lock, save);

}

EXPORT_SYMBOL_GPL(sm501_gpio_set);


/* sm501_unit_power
*
* alters the power active gate to set specific units on or off
Expand Down Expand Up @@ -906,6 +876,226 @@ static int sm501_register_display(struct sm501_devdata *sm,
return sm501_register_device(sm, pdev);
}

#ifdef CONFIG_MFD_SM501_GPIO

static inline struct sm501_gpio_chip *to_sm501_gpio(struct gpio_chip *gc)
{
return container_of(gc, struct sm501_gpio_chip, gpio);
}

static inline struct sm501_devdata *sm501_gpio_to_dev(struct sm501_gpio *gpio)
{
return container_of(gpio, struct sm501_devdata, gpio);
}

static int sm501_gpio_get(struct gpio_chip *chip, unsigned offset)

{
struct sm501_gpio_chip *smgpio = to_sm501_gpio(chip);
unsigned long result;

result = readl(smgpio->regbase + SM501_GPIO_DATA_LOW);
result >>= offset;

return result & 1UL;
}

static void sm501_gpio_set(struct gpio_chip *chip, unsigned offset, int value)

{
struct sm501_gpio_chip *smchip = to_sm501_gpio(chip);
struct sm501_gpio *smgpio = smchip->ourgpio;
unsigned long bit = 1 << offset;
void __iomem *regs = smchip->regbase;
unsigned long save;
unsigned long val;

dev_dbg(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d)\n",
__func__, chip, offset);

spin_lock_irqsave(&smgpio->lock, save);

val = readl(regs + SM501_GPIO_DATA_LOW) & ~bit;
if (value)
val |= bit;
writel(val, regs);

sm501_sync_regs(sm501_gpio_to_dev(smgpio));
spin_unlock_irqrestore(&smgpio->lock, save);
}

static int sm501_gpio_input(struct gpio_chip *chip, unsigned offset)
{
struct sm501_gpio_chip *smchip = to_sm501_gpio(chip);
struct sm501_gpio *smgpio = smchip->ourgpio;
void __iomem *regs = smchip->regbase;
unsigned long bit = 1 << offset;
unsigned long save;
unsigned long ddr;

dev_info(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d)\n",
__func__, chip, offset);

spin_lock_irqsave(&smgpio->lock, save);

ddr = readl(regs + SM501_GPIO_DDR_LOW);
writel(ddr & ~bit, regs + SM501_GPIO_DDR_LOW);

sm501_sync_regs(sm501_gpio_to_dev(smgpio));
spin_unlock_irqrestore(&smgpio->lock, save);

return 0;
}

static int sm501_gpio_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct sm501_gpio_chip *smchip = to_sm501_gpio(chip);
struct sm501_gpio *smgpio = smchip->ourgpio;
unsigned long bit = 1 << offset;
void __iomem *regs = smchip->regbase;
unsigned long save;
unsigned long val;
unsigned long ddr;

dev_dbg(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d,%d)\n",
__func__, chip, offset, value);

spin_lock_irqsave(&smgpio->lock, save);

val = readl(regs + SM501_GPIO_DATA_LOW);
if (value)
val |= bit;
else
val &= ~bit;
writel(val, regs);

ddr = readl(regs + SM501_GPIO_DDR_LOW);
writel(ddr | bit, regs + SM501_GPIO_DDR_LOW);

sm501_sync_regs(sm501_gpio_to_dev(smgpio));
writel(val, regs + SM501_GPIO_DATA_LOW);

sm501_sync_regs(sm501_gpio_to_dev(smgpio));
spin_unlock_irqrestore(&smgpio->lock, save);

return 0;
}

static struct gpio_chip gpio_chip_template = {
.ngpio = 32,
.direction_input = sm501_gpio_input,
.direction_output = sm501_gpio_output,
.set = sm501_gpio_set,
.get = sm501_gpio_get,
};

static int __devinit sm501_gpio_register_chip(struct sm501_devdata *sm,
struct sm501_gpio *gpio,
struct sm501_gpio_chip *chip)
{
struct sm501_platdata *pdata = sm->platdata;
struct gpio_chip *gchip = &chip->gpio;
unsigned base = pdata->gpio_base;

memcpy(chip, &gpio_chip_template, sizeof(struct gpio_chip));

if (chip == &gpio->high) {
base += 32;
chip->regbase = gpio->regs + SM501_GPIO_DATA_HIGH;
gchip->label = "SM501-HIGH";
} else {
chip->regbase = gpio->regs + SM501_GPIO_DATA_LOW;
gchip->label = "SM501-LOW";
}

gchip->base = base;
chip->ourgpio = gpio;

return gpiochip_add(gchip);
}

static int sm501_register_gpio(struct sm501_devdata *sm)
{
struct sm501_gpio *gpio = &sm->gpio;
resource_size_t iobase = sm->io_res->start + SM501_GPIO;
int ret;
int tmp;

dev_dbg(sm->dev, "registering gpio block %08llx\n",
(unsigned long long)iobase);

spin_lock_init(&gpio->lock);

gpio->regs_res = request_mem_region(iobase, 0x20, "sm501-gpio");
if (gpio->regs_res == NULL) {
dev_err(sm->dev, "gpio: failed to request region\n");
return -ENXIO;
}

gpio->regs = ioremap(iobase, 0x20);
if (gpio->regs == NULL) {
dev_err(sm->dev, "gpio: failed to remap registers\n");
ret = -ENXIO;
goto err_mapped;
}

/* Register both our chips. */

ret = sm501_gpio_register_chip(sm, gpio, &gpio->low);
if (ret) {
dev_err(sm->dev, "failed to add low chip\n");
goto err_mapped;
}

ret = sm501_gpio_register_chip(sm, gpio, &gpio->high);
if (ret) {
dev_err(sm->dev, "failed to add high chip\n");
goto err_low_chip;
}

gpio->registered = 1;

return 0;

err_low_chip:
tmp = gpiochip_remove(&gpio->low.gpio);
if (tmp) {
dev_err(sm->dev, "cannot remove low chip, cannot tidy up\n");
return ret;
}

err_mapped:
release_resource(gpio->regs_res);
kfree(gpio->regs_res);

return ret;
}

static void sm501_gpio_remove(struct sm501_devdata *sm)
{
int ret;

ret = gpiochip_remove(&sm->gpio.low.gpio);
if (ret)
dev_err(sm->dev, "cannot remove low chip, cannot tidy up\n");

ret = gpiochip_remove(&sm->gpio.high.gpio);
if (ret)
dev_err(sm->dev, "cannot remove high chip, cannot tidy up\n");
}

#else
static int sm501_register_gpio(struct sm501_devdata *sm)
{
return 0;
}

static void sm501_gpio_remove(struct sm501_devdata *sm)
{
}
#endif

/* sm501_dbg_regs
*
* Debug attribute to attach to parent device to show core registers
Expand Down Expand Up @@ -1059,6 +1249,8 @@ static int sm501_init_dev(struct sm501_devdata *sm)
sm501_register_usbhost(sm, &mem_avail);
if (idata->devices & (SM501_USE_UART0 | SM501_USE_UART1))
sm501_register_uart(sm, idata->devices);
if (idata->devices & SM501_USE_GPIO)
sm501_register_gpio(sm);
}

ret = sm501_check_clocks(sm);
Expand Down Expand Up @@ -1366,6 +1558,9 @@ static void sm501_dev_remove(struct sm501_devdata *sm)
sm501_remove_sub(sm, smdev);

device_remove_file(sm->dev, &dev_attr_dbg_regs);

if (sm->gpio.registered)
sm501_gpio_remove(sm);
}

static void sm501_pci_remove(struct pci_dev *dev)
Expand Down
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