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ARM: sunxi: gpio: Add Allwinner SoCs GPIO drivers
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The IP responsible for the muxing on the Allwinner SoCs are also
handling the GPIOs on the system. This patch adds the needed driver that
relies on the pinctrl driver for most of its operations.

The number of pins available for GPIOs operations are already declared
in the pinctrl driver, we only need to probe a generic driver to handle
the banks available for each SoC.

This driver has been tested on a A13-Olinuxino.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Maxime Ripard authored and Linus Walleij committed Jan 29, 2013
1 parent c54729e commit 08e9e61
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Showing 2 changed files with 156 additions and 3 deletions.
134 changes: 132 additions & 2 deletions drivers/pinctrl/pinctrl-sunxi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@
*/

#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
Expand Down Expand Up @@ -609,11 +610,53 @@ static int sunxi_pmx_enable(struct pinctrl_dev *pctldev,
return 0;
}

static int
sunxi_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned offset,
bool input)
{
struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
struct sunxi_desc_function *desc;
char pin_name[SUNXI_PIN_NAME_MAX_LEN];
const char *func;
u8 bank, pin;
int ret;

bank = (offset) / PINS_PER_BANK;
pin = (offset) % PINS_PER_BANK;

ret = sprintf(pin_name, "P%c%d", 'A' + bank, pin);
if (!ret)
goto error;

if (input)
func = "gpio_in";
else
func = "gpio_out";

desc = sunxi_pinctrl_desc_find_function_by_name(pctl,
pin_name,
func);
if (!desc) {
ret = -EINVAL;
goto error;
}

sunxi_pmx_set(pctldev, offset, desc->muxval);

ret = 0;

error:
return ret;
}

static struct pinmux_ops sunxi_pmx_ops = {
.get_functions_count = sunxi_pmx_get_funcs_cnt,
.get_function_name = sunxi_pmx_get_func_name,
.get_function_groups = sunxi_pmx_get_func_groups,
.enable = sunxi_pmx_enable,
.gpio_set_direction = sunxi_pmx_gpio_set_direction,
};

static struct pinctrl_desc sunxi_pctrl_desc = {
Expand All @@ -622,6 +665,60 @@ static struct pinctrl_desc sunxi_pctrl_desc = {
.pmxops = &sunxi_pmx_ops,
};

static int sunxi_pinctrl_gpio_request(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_request_gpio(chip->base + offset);
}

static void sunxi_pinctrl_gpio_free(struct gpio_chip *chip, unsigned offset)
{
pinctrl_free_gpio(chip->base + offset);
}

static int sunxi_pinctrl_gpio_direction_input(struct gpio_chip *chip,
unsigned offset)
{
return pinctrl_gpio_direction_input(chip->base + offset);
}

static int sunxi_pinctrl_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct sunxi_pinctrl *pctl = dev_get_drvdata(chip->dev);

u32 reg = sunxi_data_reg(offset);
u8 index = sunxi_data_offset(offset);
u32 val = (readl(pctl->membase + reg) >> index) & DATA_PINS_MASK;

return val;
}

static int sunxi_pinctrl_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
return pinctrl_gpio_direction_output(chip->base + offset);
}

static void sunxi_pinctrl_gpio_set(struct gpio_chip *chip,
unsigned offset, int value)
{
struct sunxi_pinctrl *pctl = dev_get_drvdata(chip->dev);
u32 reg = sunxi_data_reg(offset);
u8 index = sunxi_data_offset(offset);

writel((value & DATA_PINS_MASK) << index, pctl->membase + reg);
}

static struct gpio_chip sunxi_pinctrl_gpio_chip = {
.owner = THIS_MODULE,
.request = sunxi_pinctrl_gpio_request,
.free = sunxi_pinctrl_gpio_free,
.direction_input = sunxi_pinctrl_gpio_direction_input,
.direction_output = sunxi_pinctrl_gpio_direction_output,
.get = sunxi_pinctrl_gpio_get,
.set = sunxi_pinctrl_gpio_set,
.can_sleep = 0,
};

static struct of_device_id sunxi_pinctrl_match[] = {
{ .compatible = "allwinner,sun5i-a13-pinctrl", .data = (void *)&sun5i_a13_pinctrl_data },
{}
Expand Down Expand Up @@ -737,7 +834,7 @@ static int sunxi_pinctrl_probe(struct platform_device *pdev)
const struct of_device_id *device;
struct pinctrl_pin_desc *pins;
struct sunxi_pinctrl *pctl;
int i, ret;
int i, ret, last_pin;

pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
if (!pctl)
Expand Down Expand Up @@ -781,9 +878,42 @@ static int sunxi_pinctrl_probe(struct platform_device *pdev)
return -EINVAL;
}

dev_info(&pdev->dev, "initialized sunXi pin control driver\n");
pctl->chip = devm_kzalloc(&pdev->dev, sizeof(*pctl->chip), GFP_KERNEL);
if (!pctl->chip) {
ret = -ENOMEM;
goto pinctrl_error;
}

last_pin = pctl->desc->pins[pctl->desc->npins - 1].pin.number;
pctl->chip = &sunxi_pinctrl_gpio_chip;
pctl->chip->ngpio = round_up(last_pin, PINS_PER_BANK);
pctl->chip->label = dev_name(&pdev->dev);
pctl->chip->dev = &pdev->dev;
pctl->chip->base = 0;

ret = gpiochip_add(pctl->chip);
if (ret)
goto pinctrl_error;

for (i = 0; i < pctl->desc->npins; i++) {
const struct sunxi_desc_pin *pin = pctl->desc->pins + i;

ret = gpiochip_add_pin_range(pctl->chip, dev_name(&pdev->dev),
pin->pin.number,
pin->pin.number, 1);
if (ret)
goto gpiochip_error;
}

dev_info(&pdev->dev, "initialized sunXi PIO driver\n");

return 0;

gpiochip_error:
ret = gpiochip_remove(pctl->chip);
pinctrl_error:
pinctrl_unregister(pctl->pctl_dev);
return ret;
}

static struct platform_driver sunxi_pinctrl_driver = {
Expand Down
25 changes: 24 additions & 1 deletion drivers/pinctrl/pinctrl-sunxi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -254,15 +254,21 @@
#define SUNXI_PINCTRL_PIN_PG30 PINCTRL_PIN(PG_BASE + 30, "PG30")
#define SUNXI_PINCTRL_PIN_PG31 PINCTRL_PIN(PG_BASE + 31, "PG31")

#define SUNXI_PIN_NAME_MAX_LEN 5

#define BANK_MEM_SIZE 0x24
#define MUX_REGS_OFFSET 0x0
#define DATA_REGS_OFFSET 0x10
#define DLEVEL_REGS_OFFSET 0x14
#define PULL_REGS_OFFSET 0x1c

#define PINS_PER_BANK 32
#define MUX_PINS_PER_REG 8
#define MUX_PINS_BITS 4
#define MUX_PINS_MASK 0x0f
#define DATA_PINS_PER_REG 32
#define DATA_PINS_BITS 1
#define DATA_PINS_MASK 0x01
#define DLEVEL_PINS_PER_REG 16
#define DLEVEL_PINS_BITS 2
#define DLEVEL_PINS_MASK 0x03
Expand All @@ -283,6 +289,8 @@ struct sunxi_desc_pin {
struct sunxi_pinctrl_desc {
const struct sunxi_desc_pin *pins;
int npins;
struct pinctrl_gpio_range *ranges;
int nranges;
};

struct sunxi_pinctrl_function {
Expand All @@ -299,6 +307,7 @@ struct sunxi_pinctrl_group {

struct sunxi_pinctrl {
void __iomem *membase;
struct gpio_chip *chip;
struct sunxi_pinctrl_desc *desc;
struct device *dev;
struct sunxi_pinctrl_function *functions;
Expand All @@ -321,7 +330,6 @@ struct sunxi_pinctrl {
.muxval = _val, \
}


/*
* The sunXi PIO registers are organized as is:
* 0x00 - 0x0c Muxing values.
Expand Down Expand Up @@ -354,6 +362,21 @@ static inline u32 sunxi_mux_offset(u16 pin)
return pin_num * MUX_PINS_BITS;
}

static inline u32 sunxi_data_reg(u16 pin)
{
u8 bank = pin / PINS_PER_BANK;
u32 offset = bank * BANK_MEM_SIZE;
offset += DATA_REGS_OFFSET;
offset += pin % PINS_PER_BANK / DATA_PINS_PER_REG * 0x04;
return round_down(offset, 4);
}

static inline u32 sunxi_data_offset(u16 pin)
{
u32 pin_num = pin % DATA_PINS_PER_REG;
return pin_num * DATA_PINS_BITS;
}

static inline u32 sunxi_dlevel_reg(u16 pin)
{
u8 bank = pin / PINS_PER_BANK;
Expand Down

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