[RFC PATCH v2 08/16] gpio: sch: Consolidate core and resume banks

Mika Westerberg
2014-09-16T11:53:15Z

This is actually a single device with two sets of identical registers,
which just happen to start from a different offset. Instead of having
separate GPIO chips created we consolidate them to be single GPIO chip.

In addition having a single GPIO chip allows us to handle ACPI GPIO
translation in the core in a more generic way, since the two GPIO chips
share the same parent ACPI device.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/gpio/gpio-sch.c | 293 ++++++++++++++++++------------------------------
1 file changed, 112 insertions(+), 181 deletions(-)

diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c
index 41e91d70301e..99720c8bc8ed 100644
--- a/drivers/gpio/gpio-sch.c
+++ b/drivers/gpio/gpio-sch.c
@@ -29,290 +29,221 @@

#include <linux/gpio.h>

-static DEFINE_SPINLOCK(gpio_lock);
-
-#define CGEN (0x00)
-#define CGIO (0x04)
-#define CGLV (0x08)
-
-#define RGEN (0x20)
-#define RGIO (0x24)
-#define RGLV (0x28)
-
-static unsigned short gpio_ba;
-
-static int sch_gpio_core_direction_in(struct gpio_chip *gc, unsigned gpio_num)
-{
- u8 curr_dirs;
- unsigned short offset, bit;
-
- spin_lock(&gpio_lock);
-
- offset = CGIO + gpio_num / 8;
- bit = gpio_num % 8;
-
- curr_dirs = inb(gpio_ba + offset);
-
- if (!(curr_dirs & (1 << bit)))
- outb(curr_dirs | (1 << bit), gpio_ba + offset);
+#define GEN 0x00
+#define GIO 0x04
+#define GLV 0x08
+
+struct sch_gpio {
+ struct gpio_chip chip;
+ spinlock_t lock;
+ unsigned short iobase;
+ unsigned short core_base;
+ unsigned short resume_base;
+};

- spin_unlock(&gpio_lock);
- return 0;
-}
+#define to_sch_gpio(c) container_of(c, struct sch_gpio, chip)

-static int sch_gpio_core_get(struct gpio_chip *gc, unsigned gpio_num)
+static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio,
+ unsigned reg)
{
- int res;
- unsigned short offset, bit;
+ unsigned base = 0;

- offset = CGLV + gpio_num / 8;
- bit = gpio_num % 8;
+ if (gpio >= sch->resume_base) {
+ gpio -= sch->resume_base;
+ base += 0x20;
+ }

- res = !!(inb(gpio_ba + offset) & (1 << bit));
- return res;
+ return base + reg + gpio / 8;
}

-static void sch_gpio_core_set(struct gpio_chip *gc, unsigned gpio_num, int val)
+static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio)
{
- u8 curr_vals;
- unsigned short offset, bit;
-
- spin_lock(&gpio_lock);
-
- offset = CGLV + gpio_num / 8;
- bit = gpio_num % 8;
-
- curr_vals = inb(gpio_ba + offset);
-
- if (val)
- outb(curr_vals | (1 << bit), gpio_ba + offset);
- else
- outb((curr_vals & ~(1 << bit)), gpio_ba + offset);
- spin_unlock(&gpio_lock);
+ if (gpio >= sch->resume_base)
+ gpio -= sch->resume_base;
+ return gpio % 8;
}

-static int sch_gpio_core_direction_out(struct gpio_chip *gc,
- unsigned gpio_num, int val)
+static void sch_gpio_enable(struct sch_gpio *sch, unsigned gpio)
{
- u8 curr_dirs;
unsigned short offset, bit;
+ u8 enable;

- spin_lock(&gpio_lock);
+ spin_lock(&sch->lock);

- offset = CGIO + gpio_num / 8;
- bit = gpio_num % 8;
-
- curr_dirs = inb(gpio_ba + offset);
- if (curr_dirs & (1 << bit))
- outb(curr_dirs & ~(1 << bit), gpio_ba + offset);
+ offset = sch_gpio_offset(sch, gpio, GEN);
+ bit = sch_gpio_bit(sch, gpio);

- spin_unlock(&gpio_lock);
+ enable = inb(sch->iobase + offset);
+ if (!(enable & (1 << bit)))
+ outb(enable | (1 << bit), sch->iobase + offset);

- /*
- * according to the datasheet, writing to the level register has no
- * effect when GPIO is programmed as input.
- * Actually the the level register is read-only when configured as input.
- * Thus presetting the output level before switching to output is _NOT_ possible.
- * Hence we set the level after configuring the GPIO as output.
- * But we cannot prevent a short low pulse if direction is set to high
- * and an external pull-up is connected.
- */
- sch_gpio_core_set(gc, gpio_num, val);
- return 0;
+ spin_unlock(&sch->lock);
}

-static struct gpio_chip sch_gpio_core = {
- .label = "sch_gpio_core",
- .owner = THIS_MODULE,
- .direction_input = sch_gpio_core_direction_in,
- .get = sch_gpio_core_get,
- .direction_output = sch_gpio_core_direction_out,
- .set = sch_gpio_core_set,
-};
-
-static int sch_gpio_resume_direction_in(struct gpio_chip *gc,
- unsigned gpio_num)
+static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
{
+ struct sch_gpio *sch = to_sch_gpio(gc);
u8 curr_dirs;
unsigned short offset, bit;

- spin_lock(&gpio_lock);
+ spin_lock(&sch->lock);

- offset = RGIO + gpio_num / 8;
- bit = gpio_num % 8;
+ offset = sch_gpio_offset(sch, gpio_num, GIO);
+ bit = sch_gpio_bit(sch, gpio_num);

- curr_dirs = inb(gpio_ba + offset);
+ curr_dirs = inb(sch->iobase + offset);

if (!(curr_dirs & (1 << bit)))
- outb(curr_dirs | (1 << bit), gpio_ba + offset);
+ outb(curr_dirs | (1 << bit), sch->iobase + offset);

- spin_unlock(&gpio_lock);
+ spin_unlock(&sch->lock);
return 0;
}

-static int sch_gpio_resume_get(struct gpio_chip *gc, unsigned gpio_num)
+static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
{
+ struct sch_gpio *sch = to_sch_gpio(gc);
+ int res;
unsigned short offset, bit;

- offset = RGLV + gpio_num / 8;
- bit = gpio_num % 8;
+ offset = sch_gpio_offset(sch, gpio_num, GLV);
+ bit = sch_gpio_bit(sch, gpio_num);
+
+ res = !!(inb(sch->iobase + offset) & (1 << bit));

- return !!(inb(gpio_ba + offset) & (1 << bit));
+ return res;
}

-static void sch_gpio_resume_set(struct gpio_chip *gc,
- unsigned gpio_num, int val)
+static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
{
+ struct sch_gpio *sch = to_sch_gpio(gc);
u8 curr_vals;
unsigned short offset, bit;

- spin_lock(&gpio_lock);
+ spin_lock(&sch->lock);

- offset = RGLV + gpio_num / 8;
- bit = gpio_num % 8;
+ offset = sch_gpio_offset(sch, gpio_num, GLV);
+ bit = sch_gpio_bit(sch, gpio_num);

- curr_vals = inb(gpio_ba + offset);
+ curr_vals = inb(sch->iobase + offset);

if (val)
- outb(curr_vals | (1 << bit), gpio_ba + offset);
+ outb(curr_vals | (1 << bit), sch->iobase + offset);
else
- outb((curr_vals & ~(1 << bit)), gpio_ba + offset);
+ outb((curr_vals & ~(1 << bit)), sch->iobase + offset);

- spin_unlock(&gpio_lock);
+ spin_unlock(&sch->lock);
}

-static int sch_gpio_resume_direction_out(struct gpio_chip *gc,
- unsigned gpio_num, int val)
+static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
+ int val)
{
+ struct sch_gpio *sch = to_sch_gpio(gc);
u8 curr_dirs;
unsigned short offset, bit;

- offset = RGIO + gpio_num / 8;
- bit = gpio_num % 8;
+ spin_lock(&sch->lock);

- spin_lock(&gpio_lock);
+ offset = sch_gpio_offset(sch, gpio_num, GIO);
+ bit = sch_gpio_bit(sch, gpio_num);

- curr_dirs = inb(gpio_ba + offset);
+ curr_dirs = inb(sch->iobase + offset);
if (curr_dirs & (1 << bit))
- outb(curr_dirs & ~(1 << bit), gpio_ba + offset);
+ outb(curr_dirs & ~(1 << bit), sch->iobase + offset);

- spin_unlock(&gpio_lock);
+ spin_unlock(&sch->lock);

/*
- * according to the datasheet, writing to the level register has no
- * effect when GPIO is programmed as input.
- * Actually the the level register is read-only when configured as input.
- * Thus presetting the output level before switching to output is _NOT_ possible.
- * Hence we set the level after configuring the GPIO as output.
- * But we cannot prevent a short low pulse if direction is set to high
- * and an external pull-up is connected.
- */
- sch_gpio_resume_set(gc, gpio_num, val);
+ * according to the datasheet, writing to the level register has no
+ * effect when GPIO is programmed as input.
+ * Actually the the level register is read-only when configured as input.
+ * Thus presetting the output level before switching to output is _NOT_ possible.
+ * Hence we set the level after configuring the GPIO as output.
+ * But we cannot prevent a short low pulse if direction is set to high
+ * and an external pull-up is connected.
+ */
+ sch_gpio_set(gc, gpio_num, val);
return 0;
}

-static struct gpio_chip sch_gpio_resume = {
- .label = "sch_gpio_resume",
+static struct gpio_chip sch_gpio_chip = {
+ .label = "sch_gpio",
.owner = THIS_MODULE,
- .direction_input = sch_gpio_resume_direction_in,
- .get = sch_gpio_resume_get,
- .direction_output = sch_gpio_resume_direction_out,
- .set = sch_gpio_resume_set,
+ .direction_input = sch_gpio_direction_in,
+ .get = sch_gpio_get,
+ .direction_output = sch_gpio_direction_out,
+ .set = sch_gpio_set,
};

static int sch_gpio_probe(struct platform_device *pdev)
{
+ struct sch_gpio *sch;
struct resource *res;
- int err, id;

- id = pdev->id;
- if (!id)
- return -ENODEV;
+ sch = devm_kzalloc(&pdev->dev, sizeof(*sch), GFP_KERNEL);
+ if (!sch)
+ return -ENOMEM;

res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res)
return -EBUSY;

- if (!request_region(res->start, resource_size(res), pdev->name))
+ if (!devm_request_region(&pdev->dev, res->start, resource_size(res),
+ pdev->name))
return -EBUSY;

- gpio_ba = res->start;
+ spin_lock_init(&sch->lock);
+ sch->iobase = res->start;
+ sch->chip = sch_gpio_chip;
+ sch->chip.label = dev_name(&pdev->dev);
+ sch->chip.dev = &pdev->dev;

- switch (id) {
+ switch (pdev->id) {
case PCI_DEVICE_ID_INTEL_SCH_LPC:
- sch_gpio_core.base = 0;
- sch_gpio_core.ngpio = 10;
- sch_gpio_resume.base = 10;
- sch_gpio_resume.ngpio = 4;
+ sch->core_base = 0;
+ sch->resume_base = 10;
+ sch->chip.ngpio = 14;
+
/*
* GPIO[6:0] enabled by default
* GPIO7 is configured by the CMC as SLPIOVR
* Enable GPIO[9:8] core powered gpios explicitly
*/
- outb(0x3, gpio_ba + CGEN + 1);
+ sch_gpio_enable(sch, 8);
+ sch_gpio_enable(sch, 9);
/*
* SUS_GPIO[2:0] enabled by default
* Enable SUS_GPIO3 resume powered gpio explicitly
*/
- outb(0x8, gpio_ba + RGEN);
+ sch_gpio_enable(sch, 13);
break;

case PCI_DEVICE_ID_INTEL_ITC_LPC:
- sch_gpio_core.base = 0;
- sch_gpio_core.ngpio = 5;
- sch_gpio_resume.base = 5;
- sch_gpio_resume.ngpio = 9;
+ sch->core_base = 0;
+ sch->resume_base = 5;
+ sch->chip.ngpio = 14;
break;

case PCI_DEVICE_ID_INTEL_CENTERTON_ILB:
- sch_gpio_core.base = 0;
- sch_gpio_core.ngpio = 21;
- sch_gpio_resume.base = 21;
- sch_gpio_resume.ngpio = 9;
+ sch->core_base = 0;
+ sch->resume_base = 21;
+ sch->chip.ngpio = 30;
break;

default:
- err = -ENODEV;
- goto err_sch_gpio_core;
+ return -ENODEV;
}

- sch_gpio_core.dev = &pdev->dev;
- sch_gpio_resume.dev = &pdev->dev;
-
- err = gpiochip_add(&sch_gpio_core);
- if (err < 0)
- goto err_sch_gpio_core;
+ platform_set_drvdata(pdev, sch);

- err = gpiochip_add(&sch_gpio_resume);
- if (err < 0)
- goto err_sch_gpio_resume;
-
- return 0;
-
-err_sch_gpio_resume:
- gpiochip_remove(&sch_gpio_core);
-
-err_sch_gpio_core:
- release_region(res->start, resource_size(res));
- gpio_ba = 0;
-
- return err;
+ return gpiochip_add(&sch->chip);
}

static int sch_gpio_remove(struct platform_device *pdev)
{
- struct resource *res;
- if (gpio_ba) {
-
- gpiochip_remove(&sch_gpio_core);
- gpiochip_remove(&sch_gpio_resume);
-
- res = platform_get_resource(pdev, IORESOURCE_IO, 0);
-
- release_region(res->start, resource_size(res));
- gpio_ba = 0;
- }
+ struct sch_gpio *sch = platform_get_drvdata(pdev);

+ gpiochip_remove(&sch->chip);
return 0;
}

--
2.1.0