[RFC PATCH 10/16] pinctrl: samsung: Use one GPIO chip per pin bank
Tomasz Figa
t.figa at samsung.com
Fri Sep 28 10:28:41 EDT 2012
This patch modifies the pinctrl-samsung driver to register one GPIO chip
per pin bank, instead of a single chip for all pin banks of the
controller.
It simplifies GPIO accesses a lot (constant time instead of looping
through the list of banks to find the right one) and should have a good
effect on performance of any bit-banging driver.
In addition it allows to reference GPIO pins by a phandle to the bank
node and a local pin offset inside of the bank (similar to previous
gpiolib driver), which is more clear and readable than using indices
relative to the whole pin controller.
Example:
device {
/* ... */
gpios = <&gpk0 4 0>;
/* ... */
};
Signed-off-by: Tomasz Figa <t.figa at samsung.com>
---
drivers/pinctrl/pinctrl-samsung.c | 118 +++++++++++++++++++++++---------------
drivers/pinctrl/pinctrl-samsung.h | 12 ++--
2 files changed, 80 insertions(+), 50 deletions(-)
diff --git a/drivers/pinctrl/pinctrl-samsung.c b/drivers/pinctrl/pinctrl-samsung.c
index e63a365..5b85d7b 100644
--- a/drivers/pinctrl/pinctrl-samsung.c
+++ b/drivers/pinctrl/pinctrl-samsung.c
@@ -48,6 +48,11 @@ struct pin_config {
static unsigned int pin_base = 0;
+static inline struct samsung_pin_bank *gc_to_pin_bank(struct gpio_chip *gc)
+{
+ return container_of(gc, struct samsung_pin_bank, gpio_chip);
+}
+
/* check if the selector is a valid pin group selector */
static int samsung_get_group_count(struct pinctrl_dev *pctldev)
{
@@ -333,9 +338,12 @@ static int samsung_pinmux_gpio_set_direction(struct pinctrl_dev *pctldev,
void __iomem *reg;
u32 data, pin_offset, mask, shift;
+ bank = gc_to_pin_bank(range->gc);
drvdata = pinctrl_dev_get_drvdata(pctldev);
- pin_to_reg_bank(drvdata, offset, ®, &pin_offset, &bank);
+ pin_offset = offset - bank->pin_base;
+ reg = drvdata->virt_base + bank->pctl_offset;
+
mask = (1 << bank->func_width) - 1;
shift = pin_offset * bank->func_width;
@@ -469,17 +477,16 @@ static struct pinconf_ops samsung_pinconf_ops = {
/* gpiolib gpio_set callback function */
static void samsung_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
{
+ struct samsung_pin_bank *bank = gc_to_pin_bank(gc);
void __iomem *reg;
- u32 pin_offset, data;
- struct samsung_pinctrl_drv_data *drvdata;
+ u32 data;
- drvdata = dev_get_drvdata(gc->dev);
+ reg = bank->drvdata->virt_base + bank->pctl_offset;
- pin_to_reg_bank(drvdata, offset, ®, &pin_offset, NULL);
data = readl(reg + DAT_REG);
- data &= ~(1 << pin_offset);
+ data &= ~(1 << offset);
if (value)
- data |= 1 << pin_offset;
+ data |= 1 << offset;
writel(data, reg + DAT_REG);
}
@@ -487,14 +494,13 @@ static void samsung_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
static int samsung_gpio_get(struct gpio_chip *gc, unsigned offset)
{
void __iomem *reg;
- u32 pin_offset, data;
- struct samsung_pinctrl_drv_data *drvdata;
+ u32 data;
+ struct samsung_pin_bank *bank = gc_to_pin_bank(gc);
- drvdata = dev_get_drvdata(gc->dev);
+ reg = bank->drvdata->virt_base + bank->pctl_offset;
- pin_to_reg_bank(drvdata, offset, ®, &pin_offset, NULL);
data = readl(reg + DAT_REG);
- data >>= pin_offset;
+ data >>= offset;
data &= 1;
return data;
}
@@ -726,12 +732,15 @@ static int __init samsung_pinctrl_register(struct platform_device *pdev,
return -EINVAL;
}
- drvdata->grange.name = "samsung-pctrl-gpio-range";
- drvdata->grange.id = 0;
- drvdata->grange.base = drvdata->ctrl->base;
- drvdata->grange.npins = drvdata->ctrl->nr_pins;
- drvdata->grange.gc = drvdata->gc;
- pinctrl_add_gpio_range(drvdata->pctl_dev, &drvdata->grange);
+ for (bank = 0; bank < drvdata->ctrl->nr_banks; ++bank) {
+ pin_bank = &drvdata->ctrl->pin_banks[bank];
+ pin_bank->grange.name = pin_bank->name;
+ pin_bank->grange.id = bank;
+ pin_bank->grange.base = pin_bank->gpio_chip.base;
+ pin_bank->grange.npins = pin_bank->gpio_chip.ngpio;
+ pin_bank->grange.gc = &pin_bank->gpio_chip;
+ pinctrl_add_gpio_range(drvdata->pctl_dev, &pin_bank->grange);
+ }
ret = samsung_pinctrl_parse_dt(pdev, drvdata);
if (ret) {
@@ -742,49 +751,68 @@ static int __init samsung_pinctrl_register(struct platform_device *pdev,
return 0;
}
+static const struct gpio_chip samsung_gpiolib_chip = {
+ .set = samsung_gpio_set,
+ .get = samsung_gpio_get,
+ .direction_input = samsung_gpio_direction_input,
+ .direction_output = samsung_gpio_direction_output,
+ .owner = THIS_MODULE,
+};
+
/* register the gpiolib interface with the gpiolib subsystem */
static int __init samsung_gpiolib_register(struct platform_device *pdev,
struct samsung_pinctrl_drv_data *drvdata)
{
+ struct samsung_pin_ctrl *ctrl = drvdata->ctrl;
+ struct samsung_pin_bank *bank = ctrl->pin_banks;
struct gpio_chip *gc;
int ret;
-
- gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
- if (!gc) {
- dev_err(&pdev->dev, "mem alloc for gpio_chip failed\n");
- return -ENOMEM;
- }
-
- drvdata->gc = gc;
- gc->base = drvdata->ctrl->base;
- gc->ngpio = drvdata->ctrl->nr_pins;
- gc->dev = &pdev->dev;
- gc->set = samsung_gpio_set;
- gc->get = samsung_gpio_get;
- gc->direction_input = samsung_gpio_direction_input;
- gc->direction_output = samsung_gpio_direction_output;
- gc->label = drvdata->ctrl->label;
- gc->owner = THIS_MODULE;
- ret = gpiochip_add(gc);
- if (ret) {
- dev_err(&pdev->dev, "failed to register gpio_chip %s, error "
- "code: %d\n", gc->label, ret);
- return ret;
+ int i;
+
+ for (i = 0; i < ctrl->nr_banks; ++i, ++bank) {
+ bank->gpio_chip = samsung_gpiolib_chip;
+
+ gc = &bank->gpio_chip;
+ gc->base = ctrl->base + bank->pin_base;
+ gc->ngpio = bank->nr_pins;
+ gc->dev = &pdev->dev;
+ gc->of_node = bank->of_node;
+ gc->label = bank->name;
+
+ ret = gpiochip_add(gc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register gpio_chip %s, error code: %d\n",
+ gc->label, ret);
+ goto fail;
+ }
}
return 0;
+
+fail:
+ for (--i, --bank; i >= 0; --i, --bank)
+ if (gpiochip_remove(&bank->gpio_chip))
+ dev_err(&pdev->dev, "gpio chip %s remove failed\n",
+ bank->gpio_chip.label);
+ return ret;
}
/* unregister the gpiolib interface with the gpiolib subsystem */
static int __init samsung_gpiolib_unregister(struct platform_device *pdev,
struct samsung_pinctrl_drv_data *drvdata)
{
- int ret = gpiochip_remove(drvdata->gc);
- if (ret) {
+ struct samsung_pin_ctrl *ctrl = drvdata->ctrl;
+ struct samsung_pin_bank *bank = ctrl->pin_banks;
+ int ret = 0;
+ int i;
+
+ for (i = 0; !ret && i < ctrl->nr_banks; ++i, ++bank)
+ ret = gpiochip_remove(&bank->gpio_chip);
+
+ if (ret)
dev_err(&pdev->dev, "gpio chip remove failed\n");
- return ret;
- }
- return 0;
+
+ return ret;
}
static const struct of_device_id samsung_pinctrl_dt_match[];
diff --git a/drivers/pinctrl/pinctrl-samsung.h b/drivers/pinctrl/pinctrl-samsung.h
index 470e11b..f27b1e0 100644
--- a/drivers/pinctrl/pinctrl-samsung.h
+++ b/drivers/pinctrl/pinctrl-samsung.h
@@ -23,6 +23,8 @@
#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/machine.h>
+#include <linux/gpio.h>
+
/* register offsets within a pin bank */
#define DAT_REG 0x4
#define PUD_REG 0x8
@@ -113,6 +115,8 @@ struct samsung_pinctrl_drv_data;
* @of_node: node of pin bank in device tree
* @drvdata: link to controller driver data
* @irq_domain: IRQ domain of the bank.
+ * @gpio_chip: GPIO chip of the bank.
+ * @grange: linux gpio pin range supported by this bank.
*/
struct samsung_pin_bank {
u32 pctl_offset;
@@ -130,6 +134,9 @@ struct samsung_pin_bank {
struct device_node *of_node;
struct samsung_pinctrl_drv_data *drvdata;
struct irq_domain *irq_domain;
+
+ struct gpio_chip gpio_chip;
+ struct pinctrl_gpio_range grange;
};
/**
@@ -199,8 +206,6 @@ struct samsung_pin_ctrl {
* @nr_groups: number of such pin groups.
* @pmx_functions: list of pin functions available to the driver.
* @nr_function: number of such pin functions.
- * @gc: gpio_chip instance registered with gpiolib.
- * @grange: linux gpio pin range supported by this controller.
*/
struct samsung_pinctrl_drv_data {
void __iomem *virt_base;
@@ -217,9 +222,6 @@ struct samsung_pinctrl_drv_data {
unsigned int nr_functions;
struct irq_domain *wkup_irqd;
-
- struct gpio_chip *gc;
- struct pinctrl_gpio_range grange;
};
/**
--
1.7.12
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